JP3953471B2 - Door opening / closing mechanism - Google Patents

Description

  The present invention relates to a door opening / closing mechanism, and more particularly to a door opening / closing mechanism that opens and closes a door attached to a front surface of a frame.

  FIG. 16 is a front view showing a schematic configuration of a conventional lifting device used in a kitchen, and FIG. 17 is a cross-sectional view of the XVII-XVII line shown in FIG.

  Referring to these drawings, a lifting case 2 having a box shape with the front face opened is housed in a storage case 3 having a box shape with the front face open to constitute a pair of parallel support links. The lifting shelf 2 is supported by the front support links 13a and 13b and the rear support links 14a and 14b. Since the lifting device 81 is configured symmetrically, only the configuration and operation on the left side of the lifting shelf 2 will be described below.

  In the left part of the lifting device 81, the upper end of the front support link 13a is rotatably attached to a mounting plate 10a on the side plate 9a of the lifting shelf 2 via a shaft 11a, and its lower end is a storage case. 3 is attached to a mechanism box 54a fixed to the inner surface of the support plate 6a via a shaft 52a. Further, the upper end portion of the rear support link 14a is rotatably attached to the mounting plate 10a via the shaft 12a, and the lower portion thereof is fixed to a turning shaft 53a inserted into the mechanism box 54a. . Since the elevating shelf 2 is supported in this manner, the elevating shelf 2 can be moved freely from the open surface of the storage case to the front and lower side between the positions of the two-dot chain line shown in FIG. Is possible.

  A spiral spring 56a and an oil damper 55a are mounted inside the mechanism box 54a.

  The spiral spring 56a has an inner end fixed to a rotating shaft 53a inserted through the mechanism box 54a, and an outer end fixed to a portion other than the rotating shaft 53a. The spiral spring 56a urges the rotation shaft 53a in a direction opposite to the rotation direction of the rotation shaft 53a generated by pulling the lifting shelf 2 to reduce the force required for the storage operation of the lifting shelf 2. It is what is installed.

  The upper end of the oil damper 55a is rotatably attached to the mechanism box 54a via a shaft, and the lower end of the oil damper 55a is freely rotatable to a damper mounting shaft 57a inserted into the mechanism box 54a. Installed on. The damper mounting shaft 57a is connected to the lower end of the rear support link 14a outside the mechanism box 54a. When the damper mounting shaft 57a moves around the rotation shaft 53a along with the rotation of the rear support link 14a, the oil damper 55a is expanded and contracted to exert its buffering action. Is suppressed.

  Since the lifting / lowering device 81 is configured in this way, in use, it is possible to take in and out articles such as tableware after grasping the handle 4 of the lifting / lowering shelf 2 and pulling it forward and downward. Therefore, even if the lifting / lowering device 81 is mounted at a high position, the storing operation is easy and the usability is good.

  In the conventional lifting device as described above, since the front surface of the storage case is opened, dust and the like are likely to enter the inside of the lifting shelf. Since it is visible, there is a problem that the appearance of the storage state is not good.

  Therefore, for example, it is conceivable to attach a door that can be opened and closed by lifting from the lower side to the upper side around the upper side portion on the front surface of the storage case. As a result, dust and the like can be prevented from entering the inside of the storage case, and the appearance is also clean.

  However, simply attaching such a door to the storage case necessitates a separate operation for opening and closing the door when the lifting shelf is used. Further, when raising and lowering the lifting shelf, it is necessary to consider, for example, that the user supports the door with his / her hand so that the door opened upward is not closed by its own weight. If it does so, it will require the effort more than before in order to store articles | goods etc. in a raising / lowering shelf, It cannot be said that it is convenient. Furthermore, if no means is provided so that such a door can be kept closed with respect to the storage case, a gap will be generated between the storage case and the door. It is difficult to completely prevent intrusion.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a door opening / closing mechanism that can be easily opened and closed and that is stable and easy to use. To do.

  In order to achieve the above object, the invention described in claim 1 is a door opening / closing mechanism that opens and closes a door attached to the front surface of a frame body whose front surface is open, and the door opens less than a predetermined amount from the closed state. In the first range up to the opened state, the door is biased to the closed state, and in the second range in which the door is opened to the open state beyond the predetermined amount, the door is biased to the open state. A biasing means and a moving means for moving the door between a closed state and an open state by receiving an external force, the door being pivotably mounted about a shaft disposed above the door, The moving means includes an arm whose one end is pivotally attached via a first shaft at a position a predetermined distance away from the shaft on the back surface of the door. The biasing means is a support plate in which the part below the center of gravity constitutes the side surface of the frame The other end of the arm is attached to the inner surface via a third shaft at a portion above a straight line passing through the first shaft and the second shaft. The arm is composed of a weight member that is pivotably attached. The arm moves the door around the shaft body by receiving an external force through the weight member, and moves the door from the closed state to the opened state by a predetermined amount. The weight member is moved from the first position where the center of gravity is disposed on the rear side of the second axis to the second position where the center of gravity is disposed vertically above the second axis, and the door is opened by a predetermined amount. Along with the movement from the state to the open state, the weight member is moved from the second position to the third position where the center of gravity is arranged on the front side of the second shaft.

  If comprised in this way, a door will open and close according to the moving means which received external force, and will be urged | biased in the closing direction in the 1st range, and will be urged | biased in the opening direction in the 2nd range. When the door is in the first range, the center of gravity of the weight member is on the rear side of the second shaft, and the door is urged in the closing direction by the rotational force to the first position due to its own weight. When it is in the range of 2, the center of gravity of the weight member is on the front side of the second shaft, and is biased in the direction of opening the door by the rotational force to the third position due to its own weight.

  According to a second aspect of the present invention, in the configuration of the first aspect of the invention, when the door is in the open state, the third axis is arranged on a straight line.

  With this configuration, when the door is in the open state, the moment of force that causes the door to rotate the weight member due to its own weight disappears.

  According to a third aspect of the present invention, in the configuration of the second aspect of the present invention, when the door is in the open state, the weight member is further stopped at the third position.

  If comprised in this way, a weight member will stop reliably in a 3rd position.

  According to a fourth aspect of the present invention, in the configuration of the first aspect of the present invention, the weight member is located between the second position and the third position when no external force is applied. 4, the magnitude of the moment of force that rotates the weight member about the second axis toward the first position, and the weight member at the third position about the second axis. The magnitude of the moment of the force that rotates to the side is equal.

  With this configuration, in a state where no external force is applied, when the weight member is between the first position and the fourth position, the force works to rotate the weight member to the first position, When the weight member is between the fourth position and the third position, a force acts to rotate the weight member to the third position.

  According to a fifth aspect of the present invention, in the configuration of the fourth aspect of the present invention, the frame is attached to the frame so as to be movable up and down from the front side to the front and lower side through a parallel support link including a front support link and a rear support link. The lifting shelf is housed, and further includes a first roller attached to the rear support link so as to be included in substantially the same plane as the weight member, and the weight member has a first position in the first position. The fourth position is arranged in the rotation path of the roller and comes into contact with the movement of the first roller caused by the front and lower drawer of the lifting shelf, and moves from the first position to the third position. It moves to a position exceeding.

  If comprised in this way, a door will move to the opening direction with the drawer | drawing-out of a raising / lowering shelf, and a weight member will move to a 4th position and a 3rd position.

  According to a sixth aspect of the present invention, in the configuration of the fifth aspect of the invention, the weight member deviates from the rotation track of the first roller when in the third position.

  If comprised in this way, after the door is made into an open state in the drawer | drawing-out process of a raising / lowering shelf, a back support link will be movable without interfering with a weight member.

  The invention according to claim 7 is the configuration of the invention according to claim 6, further comprising a second roller attached to the front support link so as to be included in substantially the same plane as the weight member. The third position is included in the rotation path of the second roller, and comes into contact with the movement of the second roller caused by the storage of the lifting shelf in the frame, and from the third position to the second position. It moves to a position exceeding the fourth position toward the position 1.

  If comprised in this way, a door will move to the closing direction with accommodation of a raising / lowering shelf, and a weight member will move to between the 1st position and the 4th position.

  As described above, according to the first aspect of the present invention, the door opens and closes according to the moving means that receives an external force, so that the door can be opened and closed without touching the hand. In addition, since the first range is biased in the closing direction, the closed state of the door is stable, and in the second range, the opening direction is biased, so the force required to open the door is reduced. It is easy to use. Further, since the biasing force against the door changes due to the rotational force around the second axis according to the gravity center position of the weight member, the switching point and size of the biasing force against the door can be easily changed depending on the gravity center position of the weight member. It becomes possible. Further, since no power is required and no spring or the like is used, wear and the like are reduced, and durability and reliability of the door opening / closing mechanism are improved.

  In the invention according to claim 2, in addition to the effect of the invention according to claim 1, when the door is in the open state, the moment of the force for rotating the weight member due to the weight of the door disappears. Does not move in the closing direction, and the open state is stable.

  According to the third aspect of the present invention, in addition to the effect of the second aspect of the invention, the weight member surely stops at the third position, so that the door is stably maintained in the maximum open state.

  According to a fourth aspect of the present invention, in addition to the effect of the first aspect of the present invention, the weight member is located between the first position and the fourth position when no external force is applied. In this case, since the force acts to rotate the weight member to the first position, the door automatically moves in the closing direction, and the operation for closing the door becomes easy. In addition, when the weight member is between the fourth position and the third position, a force acts to rotate the weight member to the third position, so that the door automatically moves in the opening direction. And it is easy to use.

  According to the fifth aspect of the invention, in addition to the effect of the fourth aspect of the invention, the door moves in the opening direction as the lifting shelf is pulled out, and the weight member extends to the fourth position and the third position. Since it moves, it becomes possible to open the door in conjunction with the drawer of the lifting shelf, and the door automatically opens from the middle, so it is convenient.

  According to the sixth aspect of the invention, in addition to the effect of the fifth aspect of the invention, the rear support link can be moved without interfering with the weight member after the door is opened in the lifting shelf drawing process. Therefore, the lifting shelf can be further pulled out and used in the state where the door is completely opened.

  According to the seventh aspect of the invention, in addition to the effect of the sixth aspect of the invention, the door moves in the closing direction with the storage of the elevating shelf, and the weight member has the first position and the fourth position. Therefore, the door can be closed in conjunction with the storage of the elevating shelf, and the door is automatically closed from the middle.

  FIG. 1 is a front view showing a schematic configuration of a lifting apparatus according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II shown in FIG.

  Referring to these drawings, the lifting device 1 includes a storage case 3 having a box shape with an open front surface, a lifting shelf 2 stored in the storage case 3, and an open front surface of the storage case 3. The slide door 19 is mounted mainly so as to cover it.

  The storage case 3 is a shelf that is formed so that the front end edges of the pair of support plates 6a and 6b constituting the side surfaces have an arc shape when viewed from the side, and is mounted so as to bridge the support plates 6a and 6b in the horizontal direction. The inside of the plate 5 is divided into an upper section 74 and a lower section 75. In the width direction of the upper section 74, a pair of mechanism boxes 54a and 54b are fixed so as to contact the inner surface of each of the side plates 6a and 6b and the upper surface of the shelf plate 5, but these mechanism boxes 54a and 54b are fixed. As in the conventional example shown in FIG. 16 and FIG. 17, these are attached to facilitate the raising / lowering operation of the lifting / lowering shelf 2.

  The elevating shelf 2 has a box shape with an open front, is accommodated in an upper section 74 of the storage case 3, and is connected to the storage case 3 via a pair of parallel support links. The front support link 13a and the rear support link 14a constituting the parallel support link on the left side of the lift shelf 2 are rotatably attached to the side plate 9a of the lift shelf 2 via shafts 11a and 12a, respectively. The lower portions are respectively attached to the shaft 52a and the rotating shaft 53a of the mechanism box 54a. Similarly, the right side portion of the lift shelf 2 is connected to the mechanism box 54b via the front support link 13b and the rear support link 14b constituting the parallel support link.

  Since the elevating shelf 2 and the storage case 3 are attached in this manner, the elevating shelf 2 can be pulled out from the upper section 74 to the front and lower side with the handle 4 attached to the front and lower side of the elevating shelf 2. It is possible to move.

  The slide door 19 attached to the storage case 3 mainly includes an upper door 20 that covers substantially the entire upper section 74 of the storage case 3 and a lower door 21 that covers substantially the entire lower section 75. After sliding the lower door 21 so as to overlap the upper door 20, the slide door 19 is opened and closed so as to be lifted upward around the hinge 7 in a state where the upper door 20 and the lower door 21 are integrated. The details are described later.

  Further, door opening / closing mechanisms 60a and 60b are respectively formed on the inner surfaces of the support plates 6a and 6b of the storage case 3. These door opening / closing mechanisms 60a and 60b are for opening and closing the slide door 19 in accordance with the lifting and lowering operation of the lifting shelf 2, which will be described in detail later.

  A long hole 18 is formed in the side surface of the mechanism box 54a. The long hole 18 connects the rear support link 14a and a buffer means such as an oil damper inside the mechanism box 54a by a shaft. belongs to. The stopper 8 attached to the side surface of the mechanism box 54a is connected to the rear edge of the rear support link 14a when the elevating shelf 2 is stored in the upper section 74 and fully pulled out in the front and lower direction. It is for contact | abutting and regulating the movement of the raising / lowering shelf 2 more than necessary.

  First, the configuration and operation of the slide door 19 that covers the front surface of the lifting device 1 will be described in detail.

  FIG. 3 is a partially broken view showing a schematic configuration of the slide door in the lifting apparatus according to the first embodiment of the present invention, and FIG. 4 is an enlarged end view of the IV-IV line shown in FIG. FIG. 5 is an enlarged cross-sectional view of the VV line shown in FIG. In addition, since the sliding door is comprised symmetrically with right and left, it demonstrates centering on the left side part here.

  With reference to these drawings, the upper door 20 constituting a part of the slide door 19 includes a pair of frames 23a extending in an arc shape along the front end edges of the support plates 6a and 6b of the storage case 3. 23b and the panel 22 that covers the open front surface of the upper section 74, and the upper part of the panel 22 is rotatably attached to the storage case 3 via the hinge 7. The frame body 23 a is formed with a rail portion 24 positioned on the support plate 6 a side and a support portion 25 on the outer side of the rail portion 24 in a cross section in the direction extending vertically, and the panel 22 is formed on the support portion 25. It is being fixed to the frame 23a in the state pinched | interposed.

  The lower door 21 constituting another part of the slide door 19 has a vertical cross section formed into an arc shape along the front end edges of the support plates 6a and 6b, and has a shape of a part of a cylindrical side wall as a whole. 26 is the center. On both surfaces within a predetermined range from the left edge of the panel 26, reinforcing plates 28a and 28b extending vertically are attached to form a belt-like edge 27a. A reinforcing plate is similarly attached to the right side of the panel 26 to form an end edge portion 27b.

  The lower door 21 configured as described above is supported by the frame bodies 23a and 23b so that the pair of edge portions 27a and 27b can slide inside the rail portion 24 of the upper door 20. . Therefore, the lower door 21 can move slidably along the arc shape in the space between the frame bodies 23a and 23b.

  In addition, rails 29a and 29b extending vertically along the arc shape of the support plates 6a and 6b are attached to portions corresponding to the lower section 75 at the front edges of the support plates 6a and 6b of the storage case 3. The rails 29a and 29b are formed to have a U-shaped portion in the cross section in the extending direction. When the upper door 20 is closed, each of the U-shaped portions and the rails of the frame bodies 23a and 23b are formed. Each of the parts constitutes a continuous arc-shaped rail body. Therefore, when the upper door 20 is closed, the edge portions 27a and 27b of the lower door 21 can slide continuously inside the rail portions of the frame bodies 23a and 23b and inside the rails 29a and 29b. It is possible to move the door 21 between a position covering the front surface of the lower section 75 and a position covering the front surface of the upper section 74.

  Further, an urging means for urging the lower door 21 is configured in an upper portion of the upper door 20. The urging means includes a rotating shaft 30 arranged so as to bridge the frame bodies 23a and 23b, a coil spring 34 attached so as to surround the rotating shaft 30, and both ends of the rotating shaft 30. A box-shaped configuration comprising the winding drums 31a and 31b attached and the wires 32a and 32b wound around the winding drums 31a and 31b, each of which is connected to the upper part of the lower door 21. Is housed in a case 33 having Both ends of the coil spring 34 are fixed to the spring block 35 and the case 33, respectively, and the winding direction of the rotating shaft 30 is generated by pulling the wires 32 a and 32 b from the winding drums 31 a and 31 b. The rotary shaft 30 is set to be urged in a direction opposite to the direction.

  Since the urging means is configured in this way, the lower door 21 is urged to a position covering the upper section 74 via the wires 32a and 32b. When the pull-out amount of the wires 32a and 32b increases, the torsion of the coil spring 30 increases, so that the force required to open the lower door 21 upward as the lower door 21 moves downward with respect to the upper door 20 is increased. It is efficiently reduced and the opening and closing operation of the lower door 21 at the time of use becomes easy.

  Further, a stopper mechanism and a lock mechanism are configured on the slide door 19 in order to fix the lower door 21 to the upper door 20. First, the configuration of the stopper mechanism will be described.

  FIG. 6 is an enlarged view of the “Y” portion shown in FIG.

  Referring to the figure, a handle member 36 is attached to the lower door 21 via an attachment member 41.

  The attachment member 41 is attached to the lower door 21 with a predetermined portion sandwiched from the lower edge of the panel 26, and has a rectangular section 42 extending along the lower edge of the panel 26, and a groove below the groove 42. A groove 43 having a circular cross section extending along the line 42 is formed. An elastic body 44 made of a material that exerts an elastic force by compression, such as foamed urethane or rubber, is attached to the inside of the groove 42 located on the upper side.

  The handle member 36 is made of, for example, an extruded product of an aluminum alloy, and has a substantially circular shaft portion 37 in cross section, a handle portion 38 that passes from the shaft portion 37 below the mounting member 41 and extends forward, and a shaft portion. A projection 40 that projects substantially vertically upward from 37 and an engagement part 39 that extends from the shaft 37 to the back side of the lower door 21 are provided. The handle member 36 is attached so that the entire shaft portion 37 is rotatable about the shaft portion 37 in a state where the shaft portion 37 is fitted in the groove 43 of the mounting member 41. The position and size of the protrusion 40 are set so that the upper end thereof is in contact with the elastic body 44 mounted in the groove 42 of the mounting member 41, and the handle member 36 is disposed at the position indicated by the solid line in the figure. Has been.

  When the lower door 21 is slid to a position where it overlaps with the upper door 20, the engaging portion 39 of the handle member 36 and the engaging piece 45 of the frame body 23a are engaged as shown by the solid line portion in the figure. ing. Thereby, the lowering of the lower door 21 is prevented, and the state where the lower door 21 is opened is stably maintained.

  In order to release the engagement between the lower door 21 and the upper door 20 from this state, the handle portion 38 of the handle member 36 is pushed downward, and the entire handle member 36 is illustrated with the shaft portion 37 as the center. Move to the position indicated by the two-dot chain line. Then, since the engaging portion 39 moves forward about the shaft portion 37, the engagement with the engaging piece 45 attached to the back side of the upper door 20 is released, and the lower door 21 is slid downward. It becomes possible to make it.

  In the state where the handle member 36 is pushed down to the position indicated by the two-dot chain line in the figure, the elastic body 44 is compressed by the projection 40 and exerts an elastic force. When the handle member 36 is released, the handle member 36 returns to a state where it can engage with the engagement piece 45 at the position shown by the solid line in the drawing.

  When the lower door 21 is engaged with the upper door 20 again, when the lower door 21 is slid upward with the handle portion 38, the engaging piece 45 comes into contact with the engaging portion 39 of the stopper member 36. Once bent to the back side, it is engaged with the engaging portion 39 as shown by the solid line in the figure.

  Thus, the lower door 21 is automatically engaged with the upper door 20 only by the operation of sliding upward, and the lower door 21 is engaged with the upper door 20 only by the operation of holding the handle member 36 and sliding downward. Since it is released, the lower door 21 can be easily fixed and it is easy to use.

  Next, the configuration of the lock mechanism configured on the slide door will be described.

  FIG. 7 is a view showing the main part in the cross section of the VII-VII line shown in FIG. 3, and is a view showing an outline of the lock mechanism of the slide door.

  With reference to (1) of FIG. 7, the lock mechanism includes a lock member 46 attached to the back surface of the frame body 23 b of the upper door 20 via a shaft 48, and a pin 49 attached to the storage case 3. . The lock member 46 is formed, for example, by bending a metal plate. The lock member 46 is formed with an engagement portion 47 extending in a hook shape downward and forward, and an arrow shown in the drawing centering on the shaft 48 by a biasing means (not shown). It is biased in the direction of the arrow and in the direction of the arrow. On the other hand, the pin 49 is attached to the inner surface of the support plate 6b of the storage case 3 so as to protrude in the horizontal direction. The attachment position and dimensions of the pin 49 are the axis of the lock member 46 when the slide door 19 is closed. It is set so as to be able to contact a portion above 48.

  When the slide door 19 is completely closed with respect to the storage case 3, the lock member 46 is arranged at the position shown in the figure by the pin 49. At this time, since the movement of the lower door 21 is not restricted by the lock member 46, the lower door 21 can be freely slid by releasing the stopper mechanism described above.

  In a state where the lower door 21 and the upper door 20 are integrated, as the slide door 19 is moved so as to be lifted in the direction of the arrow, the lock member 46 attached to the frame body 23b moves away from the pin 49 of the support plate 6b. Therefore, the lock member 46 gradually rotates in the direction of the arrow about the shaft 48 in accordance with a biasing force by a biasing means (not shown).

  Then, when the slide door 19 is opened until the lock member 46 is completely separated from the pin 49, the tip of the engaging portion 47 of the lock member 46 is below the slide door 19 as shown in FIG. It moves and engages with the lower door 21 while holding the mounting member 41 of the lower door 21 from below. Thereby, regardless of the engagement state of the stopper mechanism, the lower door 21 is completely fixed to the upper door 20 and is prevented from sliding downward. Therefore, even if the handle member 36 is inadvertently touched when the slide door 19 is open, there is no possibility that the lower door 21 is lowered.

  In the process of closing the slide door 19, the lock member 46 moves in the reverse direction to release the locked state of the lower door 21. That is, when the slide door 19 is moved from the state shown in FIG. 7B to the support plate 6b side, the pin 49 of the support plate 6b comes into contact with the upper portion of the lock member 46 and is not urged (not shown). The lock member 46 is gradually moved in the counterclockwise direction about the shaft 48 against the urging force by the means. When the slide door 19 is completely closed, as shown in FIG. 7 (1), the engagement between the engagement portion 47 of the lock member 46 and the attachment member 41 of the lower door 21 is completely released. .

  If the lock mechanism is configured in this manner, the lower door 21 is locked to the upper door 20 simply by opening the slide door 19, and the locked state of the lower door 21 is released simply by closing the slide door 19. In addition to the engagement between the door 21 and the upper door 20, the lower door 21 can be fixed to the upper door 20 with a simple operation.

  Next, the structure of the door opening / closing mechanism attached inside the storage case will be described in detail.

  FIG. 8 is a diagram showing a schematic configuration of a door opening / closing mechanism in the lifting apparatus according to the first embodiment of the present invention, and FIG. 9 is a sectional view taken along line IX-IX shown in FIG. 10 is a cross-sectional view taken along the line XX shown in FIG. Since the door opening / closing mechanism is configured to be symmetrical on the left and right of the lifting device, only the door opening / closing mechanism 60a configured on the left support plate 6a will be described in detail here.

  Referring to these drawings, the door opening / closing mechanism 60a is mainly composed of an arm 61 and a weight member 64 with a mounting plate 67 fixed to the inner surface of the support plate 6a as a center.

  The arm 61 constituting the moving means is attached so as to bridge the upper door 20 and the weight member 64. A front end portion of the arm 61 is rotatably attached to a door metal member 76 disposed at a position away from the rotation center of the hinge 7 on the back side of the upper door 20 via a shaft 62. The rear end portion of the arm 61 is disposed so as to face the surface of the weight member 64 on the support plate 6 a side, and is attached to the weight member 64 via a shaft 63 so as to be rotatable.

  The weight member 64 constituting the urging means is formed into a thick plate shape by, for example, overlapping a plurality of metal plates, and is attached to the attachment plate 67 via a shaft 65 at a portion below the center of gravity G so as to be rotatable. It has been. The position of the shaft 63 for attaching the arm 61 to the weight member 64 is set to be positioned above a straight line passing through the shaft 62 and the shaft 65.

  In addition, a part of the front lower side of the mounting plate 67 is bent in a direction orthogonal to the support plate 6 a to form a stopper 68. When the weight member 64 rotates about the shaft 65 in the counterclockwise direction in FIG. 8, the stopper 68 comes into contact with a part of the side surface of the weight member 64 to further increase the weight member 64 in the same direction. This is for stopping the movement.

  Further, a shock damper 66 is attached to an upper front portion of the shaft 65 in the weight member 64. The shock damper 66 is attached so that its axial direction is parallel to the tangent of a virtual circle centered on the shaft 65, and moves together with the weight member 64 so as to be rotatable about the shaft 65. Is possible. The shock damper 66 is attached in order to interfere with an impact when the weight member 64 comes into contact with the stopper 68.

  Further, an oil damper 69 is attached to the weight member 64 so as to span the attachment plate 67. The lower end portion of the oil damper 69 is pivotally attached via a shaft 70 at a rear upper part of the shaft 65 of the weight member 64, and the upper end portion is pivotally attached to a mounting plate 67 via a shaft 71. It has been. The oil damper 69 is attached to suppress a rapid movement of the slide door 19 via the weight member 64 and the arm 61.

  Furthermore, a roller 16 is rotatably attached to the front support link 13a via a roller attachment plate 15 that extends forward facing the support plate 6a, and a roller 17 is attached to the upper end of the rear support link 14a. Is rotatably mounted. The rollers 16 and 17 are both attached so as to protrude toward the support plate 6 a, and their rotational surfaces are set to be included in substantially the same plane as the moving surface of the weight member 64. These rollers 16 and 17 are for transmitting an external force applied for raising and lowering the lifting shelf from the front support link 13a or the rear support link 14a to the arm 61 via the weight member 64. Details of the operation will be described later.

  Here, the urging state of the slide door 19 by the door opening / closing mechanism 60a configured as described above will be described.

  FIG. 11 is a view showing a main part of the door opening / closing mechanism in the lifting apparatus according to the first embodiment of the present invention, for explaining the relationship between the weight member and the slide door. For the explanation in this figure, the weight of the weight member is m, and the gravitational acceleration is g.

  Referring to (1) of FIG. 11, the solid line portion in the figure shows the arrangement of each part when the slide door 19 is in the closed state, and the broken line portion indicates that the slide door 19 is opened by a predetermined amount. The arrangement of each part when in the state is shown.

First, as shown by the solid line portion in the figure, when the slide door 19 is in the closed state, the weight member 64 is in the first position where the center of gravity G is disposed on the rear side of the shaft 65. Here, if the horizontal distance between the center of gravity G and the shaft 65 in this state is l ₁ , the rotational moment due to the weight of the weight member 64 is mgl ₁ clockwise about the shaft 65. Therefore, the slide door 19 is urged in the closing direction (right direction in the drawing) via the arm 61 by the rotational force in the clockwise direction due to the weight of the weight member 64.

  Next, the arm 61 receives external force through the weight member 64 and rotates the weight member 64 about the shaft 65 in the clockwise direction as the slide door 19 is moved in the opening direction. In this process, since the center of gravity G is located behind the shaft 65, the weight member 64 is still given a clockwise rotational moment about the shaft 65 by its own weight. In addition, when the slide door 19 is opened, a part of its own weight is added to the weight member 64 via the arm 61, so that the weight member 64 is rotated clockwise around the shaft 65 by the slide door 19. A rotational moment is further applied. In other words, due to the resultant force of the weight of the weight member 64 and the force applied from the slide door 19, a clockwise rotational moment about the shaft 65 is applied to the weight member 64. It is urged to close.

Next, as shown by the broken line portion in the figure, the arm 61 receives an external force through the weight member 64 and moves the slide door 19 to a state where the slide door 19 is opened by a predetermined amount around the hinge 7. Moves the weight member 64 to a second position where the center of gravity G is disposed vertically above the shaft 65. At this time, since the weight of the weight member 64 is applied in the direction of the vertically lower shaft 65, the rotational moment due to the weight of the weight member 64 disappears. On the other hand, at this time the force acting from the slide door 19 to the weight member 64 via the arm 61 and F _1, when the orthogonal distance from the axis 65 to force F ₁ and L _1, the weight member 64, a shaft 65 A clockwise moment F ₁ L ₁ around the center is applied. Therefore, when the sliding door 19 is opened by a predetermined amount, the sliding door 19 is not biased in any direction by the weight member 64. If the external force is removed, the sliding door 19 is weighted via the arm 61 by its own weight. The member 64 moves in the closing direction while rotating.

  As described above, the slide door 19 is biased to the closed state by the weight member 64 when the slide door 19 is in the first range from the closed state to the opened state less than a predetermined amount. Therefore, the state where the slide door 19 is closed with respect to the frame body such as the storage case is stably maintained.

  Subsequently, referring to (2) of FIG. 11, the arm 61 further receives an external force via the weight member 64, thereby moving the slide door 19 beyond the predetermined amount around the hinge in a direction of further opening. Accordingly, the arm 61 moves the weight member 64 from the first position indicated by the solid line to the position indicated by the broken line. In this process, since the center of gravity G of the weight member 64 is located in front of the shaft 65, the weight member 64 is given a counterclockwise rotational moment about the shaft 65 by its own weight. As a result, a part of the moment of the force that causes the sliding door 19 to rotate the weight member 64 clockwise via the arm 61 can be offset, so that the external force required to move the sliding door 19 in the opening direction can be reduced. It becomes possible to do.

  Then, as shown in the two-dot chain line portion of the figure, the arm 61 is configured such that the center of gravity of the weight member 64 is disposed on the front side of the shaft 65 as the slide door 19 is moved to the open state. Move to the position. In this embodiment, the third position of the weight member 64 is set so that the shaft 63 of the arm 61 is arranged on a straight line passing through the shaft 62 and the shaft 65. (That is, the shaft 61, the shaft 62, and the shaft 65 are aligned in a straight line.) Therefore, the weight member 64 due to the weight of the slide door 19 is moved to the first position (clockwise around the shaft 65). The moment of the rotating force disappears, and only the counterclockwise rotational moment due to its own weight is applied to the weight member 64. Therefore, the sliding door 19 does not move in the closing direction depending on its own weight, and is biased in the direction of further opening through the arm 61 by the rotational force of the weight member 64, and thus is indicated by a two-dot chain line. It will be stably maintained in the open state.

  Further, the door opening / closing mechanism according to this embodiment is provided with a stopper 68 for stopping the weight member 64 at the third position when the slide door 19 is in the open state. Thereby, since the weight member 64 stops reliably in the 3rd position, the open state of the slide door 19 becomes more stable. Then, since the shaft 61, the shaft 62 and the shaft 65 are aligned in a straight line and the arm 61 is pushed out most outward, the slide door 19 can be stopped in the fully opened state, The storage operation after the slide door 19 is opened can be easily performed.

  Thus, the slide door 19 is biased to the open state by the weight member 64 when it is in the second range that is open to the open state beyond a predetermined amount. Therefore, the force required to move the slide door 19 to the open state is reduced, and the operation for opening the door is facilitated.

  Here, the state when the weight member 64 is between the second position and the third position will be described in more detail.

Referring again to (2) in FIG. 11, the portion indicated by a broken line in the drawing is in a range where the slide door 19 is opened beyond a predetermined amount, and the weight member 64 is in the second position (solid line portion). The state which exists in the 4th position between the 3rd position and the 3rd position (part of a dashed-two dotted line) is shown. In this state, if the horizontal distance between the center of gravity G of the weight member 64 and the shaft 65 is l ₂ , the rotational moment due to the weight of the weight member 64 is mgl ₂ counterclockwise around the shaft 65. Moreover, the force applied to the weight member 64 and F ₂ via the arm 61, when the orthogonal distance from the axis 65 to force F ₂ and L _2, by the force F ₂ exerted by its own weight or the like of its own weight or the arm of the slide door 19 The rotational moment of the weight member 64 is F ₂ L ₂ in the clockwise direction around the shaft 65.

In the storage device according to this embodiment, when the weight member 64 is at the fourth position indicated by the broken line in a state where no external force is applied, the moment of force (clockpiece) that rotates the weight member 64 to the first position is shown. The magnitude of the rotation direction) and the magnitude of the moment of force to rotate to the third position (counterclockwise direction), that is,
mgl ₂ = F ₂ L ₂
It is set to satisfy the relationship. Therefore, when the weight member 64 is in the fourth position, the force by which the weight member 64 rotates due to its own weight and the force in the direction in which the slide door 19 closes are balanced.

  When the weight member 64 moves counterclockwise beyond the fourth position to the third position (the position of the two-dot chain line), the weight is increased so that the force due to the weight of the weight member 64 becomes larger. The weight and positional relationship of the member 64, the slide door 19, and the arm 61 are set. Therefore, when the sliding door 19 is opened, if the weight member 64 is rotated from the first position to the third position by the external force to the position exceeding the fourth position, no external force is applied thereafter. However, since the weight member 64 continues to rotate further in the same direction due to its own weight, the sliding door 19 can be automatically opened to the open state indicated by the two-dot chain line by the rotational force of the weight member 64.

  On the contrary, when the weight member 64 moves clockwise beyond the fourth position to the second position (solid line position), the force due to the weight of the slide door 19 or the like becomes larger. It is configured as follows. Therefore, when closing the slide door, if the weight member 64 is rotated from the third position toward the first position by the external force to the position exceeding the fourth position, no external force is applied thereafter. The weight member 64 can continue to rotate beyond the second position by a force applied from the slide door 19 or the like. As described above, when the weight member 64 is between the second position and the first position, the weight member 64 is given a moment in the clockwise direction around the shaft 65, so that Thus, the slide door 19 can be automatically closed to the closed state.

  If comprised in this way, the urging | biasing state with respect to the slide door 19 can be changed only by the change of the gravity center position of the weight member 64, but since power is not required and a spring etc. are not used, the door opening / closing mechanism 60a Wear and the like of each part are reduced, and durability and reliability are improved. Further, by changing the position and weight of the center of gravity G of the weight member 64, it is possible to easily set the switching point and the size of the urging force with respect to the slide door 19.

  Next, the operation of the entire lifting device using the door opening / closing mechanism as described above will be described.

  FIG. 12 is a view showing a part of the lifting shelf drawing process in the lifting device according to the first embodiment of the present invention, and FIG. 13 is a drawing showing the lifting shelf drawing process following FIG. It is.

  Referring to (1) of FIG. 12, when using the lifting rack 2 stored in the upper section 74 of the storage case 3, first, the lower door 21 is indicated by a solid line above from the position indicated by the two-dot chain line. Slide to the desired position. At this time, since the upper door 20 and the lower door 21 are integrated by the stopper mechanism described above, the entire slide door 19 can be opened and closed by lifting from the lower side to the upper side around the hinge 7. It becomes. Further, by sliding the lower door 21 upward, the handle 4 is exposed in front of the lower section 75, so that the lifting shelf 2 can be pulled out with the handle 4.

  When the handle 4 is grasped and the lifting shelf 2 is moved slightly so as to be pulled out from the upper section 74 to the front and lower side, the roller 17 attached to the upper end portion of the rear support link 14a is moved to the peripheral wall surface of the rear portion of the weight member 64. Abut. As a result, an external force applied to pull out the lifting shelf 2 is transmitted to the slide door 19 via the rear support link 14a, the weight member 64, and the arm 61, and the sliding door 19 is opened in conjunction with the drawer of the lifting shelf 2. It is possible to move in the direction.

  When the lifting shelf 2 is further pulled out, the roller 17 of the rear support link 14a rotates around the rotation shaft 53a while rolling along the peripheral wall surface of the weight member 64, as shown in FIG. The arm 61 receives an external force due to the pull-out operation of the elevating shelf 2 through the weight member 64, moves the slide door 19 to a state where it is opened by a predetermined amount, and moves the weight member 64 around the shaft 65 to the first position. Is moved from the position ((1) in FIG. 12) to the second position. At this time, since the center of gravity G of the weight member 64 is disposed vertically above the shaft 65 as described above, the slide door 19 is not biased in any direction by the weight member 64.

  As described above, the lock mechanism of the slide door 19 is activated as the slide door 19 is opened, and the lower door 21 is securely fixed to the upper door 20. Therefore, there is no possibility that the lower door 21 will fall inadvertently when the slide door 19 is subsequently opened and closed.

  Subsequently, referring to (1) of FIG. 13, when the lifting shelf 2 is further pulled out, the arm 61 moves the slide door 19 in a direction to open beyond a predetermined amount. At this time, the arm 61 rotates the weight member 64 counterclockwise around the shaft 65 from the second position toward the third position, so that the center of gravity G of the weight member 64 moves forward from the shaft 65. Moving. In this process, a part of the force in the closing direction due to the weight of the slide door 19 is canceled out by the rotational force due to the weight of the weight member 64, so that the force required to open the slide door 19 is reduced. Therefore, the sliding door 19 can be easily opened in conjunction with the pulling-out operation of the lifting / lowering shelf 2, and the usability is good.

  If the elevating shelf 2 is continuously moved downward and forward, the weight member 64 moves to the third position side to the position exceeding the above-described fourth position with the movement of the roller 17 of the rear support link 14a. . When the weight member 64 is between the fourth position and the third position, the force for moving the weight member 64 to the third position acts on the weight member 64 as described above. Therefore, the weight member 64 continues to rotate counterclockwise around the shaft 65 and stops at the third position in contact with the stopper 68 as shown in (2) of FIG. When the weight member 64 comes into contact with the stopper, the shock is reduced by a shock damper attached to the weight member 64. As the weight member 64 rotates from the fourth position to the third position, the slide door 19 automatically moves in the opening direction via the arm 61 and stops in a fully opened state.

  In addition, when the weight member 64 is in the third position, the weight member 64 is inwardly disengaged from the rotation track of the roller 17 of the rear support link 14a, so that the roller 17 interferes with the weight member 64. It can be moved on the outer side. Therefore, the lifting shelf 2 can be used by being completely lowered further forward and downward from the position indicated by the two-dot chain line in FIG.

  When the door opening / closing mechanism is attached in this manner, the slide door 19 can be moved to the open state in conjunction with the drawer of the lifting shelf, and the slide door is automatically opened from the middle, which is convenient. In addition, when the weight member 64 is in the third position, the shaft 62, the shaft 63, and the shaft 65 are set so as to be aligned in a straight line. It does not move in the direction of closing with its own weight, and it is easy to use. At this time, since the weight member 64 is stopped by the stopper 68, the open state of the slide door 19 is reliably maintained.

  FIG. 14 is a diagram showing a part of the storage process of the lifting shelf in the lifting device according to the first embodiment of the present invention, and FIG. 15 is a diagram showing the storage process of the lifting shelf following FIG. It is.

  Referring to (1) of FIG. 14, in use, with the sliding door 19 opened, the lifting shelf 2 is completely lowered to the front of the lower section 75, and the articles are moved into the lifting shelf 2. It is possible to take in and out. Thereafter, when the lifting shelf 2 is stored in the storage case 3, the lifting shelf 2 is moved so as to be lifted to the upper section 74. At this time, the front support link 13a and the rear support link 14a move from the position indicated by the two-dot chain line to the position indicated by the solid line.

  As described above, when the weight member 64 is in the third position, the roller 17 is out of the rotational trajectory of the roller 17 of the rear support link 14a, so that the roller 17 contacts the weight member 64 as shown in the figure. It passes through the outer side without moving to the inner side of the storage case 3. That is, since the arm 61 cannot receive an external force via the weight member 64, the slide door 19 is maintained in an open state, and does not hinder the storage operation of the lifting shelf 2.

  When the elevating shelf 2 is further moved into the storage case 3, the roller 16 attached to the front support link 13 a via the roller attachment plate 15 is attached to the weight member 64 as shown in FIG. It contacts the peripheral wall surface of the front part. As a result, the external force applied to store the elevating shelf 2 is transmitted from the front support link 13 a to the arm 61 via the weight member 64.

  When the elevating shelf 2 is further moved, the roller 16 of the front support link 13a rotates around the shaft 52a while rolling along the peripheral wall surface of the weight member 64. The arm 61 receives external force due to the storage operation of the lifting shelf 2 via the weight member 64 and moves the slide door 19 in the closing direction, and rotates the weight member 64 clockwise about the shaft 65.

  Subsequently, referring to (1) of FIG. 15, when the elevating shelf 2 is continuously moved into the storage case 3, the weight member 64 is moved to the first position as the roller 16 of the front support link 13 a moves. Move to the position beyond the fourth position. When the weight member 64 is between the fourth position and the first position, as described above, a force for moving the weight member 64 to the first position acts on the weight member 64, so that the weight member 64 has the shaft 65. Continue to rotate clockwise around. Further, the slide door 19 moves to the closed state by its own weight.

  Then, as shown in (2) of FIG. 15, as the slide door 19 closes from the position indicated by the broken line to the position indicated by the solid line, the weight member 64 moves from the position indicated by the broken line to the second position. Then, it automatically moves to the first position indicated by the solid line.

  In the process of closing the slide door 19, the oil damper 69 attached via the weight member 64 exerts a buffering action, so that the slide door 19 is prevented from closing suddenly.

  When the sliding door 19 is completely closed, the locking mechanism is released, so the lower door 21 is lowered to a position covering the lower section 75, and the entire front surface of the storage case 3 is covered again. State.

  When the door opening / closing mechanism is attached in this manner, it can be moved to the closed state without directly touching the slide door 19 in conjunction with the storage of the elevating shelf 2, and the slide door 19 is automatically closed from the middle. Easy to use. Further, when the slide door 19 is closed, the slide door 19 is urged by the weight member 64 through the arm 61 in the closing direction, so that the slide door 19 is closed tightly with respect to the storage case 3. The state is maintained, and it is possible to effectively prevent entry of dust and the like.

  Thereafter, the operation shown in FIG. 12 to FIG. 15 is repeated every time the lifting device 1 is used, and the same usability continues for opening and closing the sliding door 19 in conjunction with the lifting operation of the lifting shelf 2.

  In the above embodiment, the storage case, which is a frame, is provided with a slide door composed of an upper door and a lower door. However, the present invention is not necessarily limited to such a slide door. May be attached.

  In the above embodiment, the weight member is set so as to be movable only from the first position to the third position. However, the weight member does not necessarily have to be configured in this manner. If the closed state corresponds to the first position of the weight member and the open state of the door corresponds to the third position of the weight member, the moving range of the weight member may be set wider. For example, the weight member may be moved beyond the third position, and may be configured to stop after moving the door in a slightly closing direction once the door is completely opened.

  Furthermore, in the above-described embodiment, the arm is configured to move the door in response to an external force applied to move the lifting shelf. However, the arm is not necessarily configured in this manner. The moving means may be configured to move the door by an external force different from the movement.

  Furthermore, in the above-described embodiment, the stopper for stopping the weight member at the third position is formed. However, the stopper is not necessarily required to be configured in this manner.

  Further, in the above embodiment, when the door is in the open state, the first shaft and the third shaft at the both ends of the arm and the second shaft of the weight member are arranged in a straight line. However, it is not always necessary to configure in this way, and these three axes may be configured to be, for example, arranged in a dogleg shape.

  Furthermore, in the above-described embodiment, when the weight member is in the fourth position, the force for closing the door by its own weight and the force for rotating the weight member by its own weight are balanced. It is not necessary to configure these two forces so that these two forces are balanced in the third position, or the door closing force is always larger (that is, the two forces are the second position and the second position). You may comprise so that it may not balance with 3rd position. Even in such a case, since the door is urged by the rotational force due to the weight of the weight member, the force required to open the door is reduced, and the same usability is exhibited.

  Further, in the above-described embodiment, a pair of door opening / closing mechanisms are attached in the width direction of the lifting device.

  Further, in the above-described embodiment, the roller of the front support link is attached via the roller mounting plate. However, it is not always necessary to configure in this manner, and the roller may be directly attached to the front support link.

  Furthermore, in the above-described embodiment, an oil damper and a shock damper are attached. However, these are not necessarily required, and one or both of them may be omitted.

  Furthermore, in the above embodiment, the present invention is applied to a lifting device used in a kitchen, but is not necessarily limited to a kitchen, and similarly applied to a lifting device used in another place such as a front door. Is possible.

It is the front view which showed schematic structure of the raising / lowering apparatus by 1st Embodiment of this invention. It is sectional drawing of the II-II line shown in FIG. It is a partially broken figure which showed schematic structure of the sliding door in the raising / lowering apparatus by 1st Embodiment of this invention. FIG. 4 is an enlarged end view of the IV-IV line shown in FIG. 3. FIG. 5 is an enlarged cross-sectional view taken along line VV shown in FIG. 3. FIG. 6 is an enlarged view of a “Y” portion shown in FIG. 5. It is the figure which showed the principal part in the cross section of the VII-VII line shown in FIG. 3, Comprising: It is the figure which showed the outline | summary of the locking mechanism of a slide door. It is the figure which showed schematic structure of the door opening / closing mechanism in the raising / lowering apparatus by 1st Embodiment of this invention. It is sectional drawing of the IX-IX line shown in FIG. It is sectional drawing of the XX line shown in FIG. It is the figure which showed the principal part of the door opening / closing mechanism in the raising / lowering apparatus by 1st Embodiment of this invention, Comprising: It is a figure for demonstrating the relationship between a weight member and a slide door. In the raising / lowering apparatus by 1st Embodiment of this invention, it is the figure which showed a part of drawer | drawing-out process of the raising / lowering shelf. It is the figure which showed the drawer process of the raising / lowering shelf following FIG. In the raising / lowering apparatus by 1st Embodiment of this invention, it is the figure which showed a part of accommodation process of the raising / lowering shelf. It is the figure which showed the accommodation process of the raising / lowering shelf following FIG. It is the front view which showed schematic structure of the conventional raising / lowering apparatus used in a kitchen. It is sectional drawing of the XVII-XVII line shown in FIG.

Explanation of symbols

2 ... Lifting shelf 3 ... Storage case 6 ... Support plate 7 ... Hinge 13 ... Front support link 14 ... Rear support link 16, 17 ... Roller 19 ... Slide door 60 ... Door open / close mechanism 61 ... Arm 62, 63, 65 ... Shaft 64 ... Weight member 68 ... Stopper In addition, the same code | symbol in each figure shows the same or an equivalent part.

Claims (7)

A door opening and closing mechanism for opening and closing a door attached to the front surface of the frame body whose front surface is open,
In a first range from the closed state to a state where the door is opened less than a predetermined amount, the door is biased to the closed state, and the door is opened to the open state beyond the predetermined amount. In a range, biasing means for biasing the door to an open state;
Moving means for moving the door between the closed state and the open state by receiving an external force;
The door is pivotally mounted around a shaft disposed above, and opens and closes so that it can be lifted upward from below.
The moving means includes an arm whose one end is rotatably attached via a first shaft at a position away from the shaft body on the back surface of the door by a predetermined distance;
The biasing means is pivotally attached to an inner surface of a support plate constituting a side surface of the frame body with a portion below the center of gravity via a second shaft, and the first shaft and the first shaft. A weight member to which the other end of the arm is rotatably attached via a third shaft to a portion above a straight line passing through the second shaft,
The arm receives the external force through the weight member, thereby moving the door around the shaft body, and moving the door from the closed state to the opened state by the predetermined amount. The weight member is moved from a first position where the center of gravity is disposed on the rear side of the second axis to a second position where the center of gravity is disposed vertically above the second axis, and the door is moved. As the predetermined amount is moved from the open state to the open state, the weight member is moved from the second position to a third position where the center of gravity is disposed on the front side of the second shaft. Door opening / closing mechanism. The door opening / closing mechanism according to claim 1, wherein the third shaft is arranged on the straight line when the door is in the open state. The door opening / closing mechanism according to claim 2, further comprising stopper means for stopping the weight member at the third position when the door is in the open state. When the weight member is in a fourth position between the second position and the third position in a state where the external force does not act, the weight member is centered on the second axis and the second The magnitude of the moment of force for rotating the first member toward the position of 1 is equal to the magnitude of the moment of force for rotating the weight member toward the third position around the second axis. The door opening / closing mechanism according to any one of claims 1 to 3. In the frame body, an elevating shelf that is mounted so as to be movable up and down from the front surface to the front and lower side through a parallel support link including a front support link and a rear support link is stored,
A first roller attached to the rear support link so as to be substantially in the same plane as the weight member;
The weight member is disposed in the rotation path of the first roller at the first position, and is moved along with the movement of the first roller caused by the front and lower drawer being pulled out. The door opening and closing mechanism according to claim 4, wherein the door opening and closing mechanism moves to a position exceeding the fourth position from the first position toward the third position. The door opening / closing mechanism according to claim 5, wherein the weight member deviates from a rotation track of the first roller when in the third position. A second roller attached to the front support link so as to be substantially in the same plane as the weight member;
In the third position, the weight member is included in the rotation path of the second roller, and the weight member is moved along with the movement of the second roller caused by the storage of the lifting shelf in the frame body. The door opening / closing mechanism according to claim 6, wherein the door opening / closing mechanism is in contact with the third position and moves from the third position toward the first position to a position exceeding the fourth position.

Images