JP6402937B2 - Base lifting device - Google Patents

Description

  The present invention relates to a gantry lifting device that lifts and lowers a ceiling gantry in a horizontal state by relatively rotating a first lift arm and a second lift arm in a standing direction or a lying direction.

  A technique related to the above-described gantry lifting device is disclosed in Patent Document 1. As shown in FIG. 10, the gantry lifting device 100 of Patent Document 1 is installed on a floor F, and is installed on the base member 102, and is in a standing direction or a lying direction in a state of crossing the X shape. And a pair of lift arms 104 and 105 connected to each other so as to be relatively rotatable, and a platform 107 (ceiling mount) installed on the pair of lift arms 104 and 105. A roller 108 is provided at a position between the pair of lift arms 104 and 105 from above and below. The roller 108 is configured to be able to approach or separate from the connection center 106 of the pair of lift arms 104 and 105 by the operation of the drive mechanism 109. When the roller 108 approaches the connection center 106 of the pair of lift arms 104 and 105 by the operation of the drive mechanism 109, the roller 108 pushes the pair of lift arms 104 and 105 up and down in a wedge shape, and the pair of lift arms 104 and 105 rise gradually and the platform 107 rises. Further, when the roller 108 is separated from the connection center 106 of the pair of lift arms 104 and 105, the pair of lift arms 104 and 105 gradually fall down following the roller 108 due to the weight of the platform 107 and the platform 107 is lowered. .

JP 2014-5086 A

  In the above-described gantry lifting device 100, it is conceivable that the lowering of the platform 107 stops due to the influence of foreign matter or the like while the platform 107 is lowered. In this case, since the operation of the drive mechanism 109 is continued in a state where the lift arms 104 and 105 have stopped rotating in the lying down direction, the roller 108 is moved down following the lower lift arm 104. As a result, the upper lift arm 105 is separated from the roller 108. Therefore, when the operation of the drive mechanism 109 is further continued, the gap between the upper lift arm 105 and the roller 108 gradually increases. For this reason, when the foreign matter or the like that has stopped the lowering of the platform 107 is removed, the platform 107 is greatly lowered by the gap between the upper lift arm 105 and the roller 108 by its own weight.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to prevent a large drop of the ceiling mount due to the influence of foreign matter or the like.

  The above-described problems are solved by the inventions of the claims. According to a first aspect of the present invention, there are provided a first lift arm and a second lift arm which are connected so as to be relatively rotatable in an upright direction or a lying down direction while intersecting with an X shape, and the first lift arm and the second lift. A gantry raising / lowering device comprising a ceiling gantry installed on the arm and moving the first and second lift arms relative to each other in an upright direction or a lying down direction so as to raise and lower the ceiling gantry in a horizontal state. A roller whose outer peripheral surface is sandwiched from above and below by the first lift arm and the second lift arm, and the roller approaching or separating from the connection center of the first lift arm and the second lift arm. By causing the first lift arm and the second lift arm to rotate relative to each other in the upright direction or the lying down direction, the first lift arm is attached to the roller. A separation detection mechanism capable of detecting separation from the circumferential surface, and a change for changing the operation of the drive mechanism when the separation detection mechanism detects that the first lift arm is separated from the outer circumferential surface of the roller. Means.

  According to the present invention, the drive mechanism causes the roller to approach the connection center between the first lift arm and the second lift arm, so that the roller spreads the first lift arm and the second lift arm up and down like a wedge. The first lift arm and the second lift arm rise and the ceiling mount rises. Further, by separating the roller with respect to the connection center between the first lift arm and the second lift arm by the driving mechanism, the first lift arm and the second lift arm gradually follow the roller by the weight of the ceiling mount or the like. The ceiling mount descends. Further, for example, when the ceiling mount is lowered due to the influence of foreign matter or the like while the ceiling mount is lowered, and the first lift arm is separated from the outer peripheral surface of the roller, the separation detection mechanism causes the first lift arm and the outer peripheral surface of the roller to A separation is detected. As a result, the changing means operates to change the operation of the drive mechanism. That is, the operation of the drive mechanism becomes slow or the operation of the drive mechanism is stopped. For example, when the operation of the drive mechanism is stopped, the drive mechanism does not continue to operate in a state where the outer peripheral surface of the roller is separated from the first lift arm on the upper side, and there is a problem that the ceiling mount is greatly lowered. Disappear.

  According to a second aspect of the present invention, the separation detecting mechanism detects whether or not the first lift arm is at a predetermined position with respect to the roller, and the first lift arm is detected when the first lift arm is not at the predetermined position. It is determined that the arm is separated from the outer peripheral surface of the roller. Thus, since it is not the structure which detects directly the contact of the upper 1st lift arm with respect to the outer peripheral surface of a roller, or a separation | separation, the freedom degree of the installation position of a separation | spacing detection mechanism becomes high.

  According to the invention of claim 3, the separation detecting mechanism is mounted on a bracket that supports a roller, and is configured to reciprocate within a certain range, and an elastic body that urges the moving member in one direction. And a switch for detecting the movement of the moving member, and when the first lift arm is in a predetermined position with respect to the roller, the moving member comes into contact with the first lift arm and is in the middle of the moving range. When the first lift arm does not exist at the predetermined position, the moving member is configured not to stop at an intermediate position in the moving range. For this reason, the presence or absence of the upper first lift arm can be reliably detected with a simple configuration.

  According to the invention of claim 4, the moving member is connected in a state where the upper end portion of the moving member is rotatable with respect to the bracket, and the moving member is an arc centering on a connecting portion with the bracket. It is configured to be able to move up and down. For this reason, when the upper first lift arm comes into contact with or moves away from the moving member, the moving member is hardly damaged.

  According to the invention of claim 5, the separation detecting mechanism is provided between the connection center of the first lift arm and the second lift arm and the roller.

  According to the present invention, it is possible to prevent a large drop of the ceiling mount due to the influence of foreign matter or the like.

It is a whole perspective view of the level | step difference resolver provided with the gantry raising / lowering apparatus which concerns on this Embodiment 1 of this invention. 1 is an overall perspective view of a gantry lifting device according to Embodiment 1. FIG. It is a side view (side view which looked at the X lift mechanism of the right side from the outer side) showing the principle of operation of the said platform raising / lowering apparatus. FIG. 4 is an enlarged view taken along arrow IV in FIG. 3. It is a front view (VV arrow view of FIG. 4) showing the installation state of a separation | spacing detection mechanism. It is the perspective view which looked at the installation state of the separation | spacing detection mechanism from the inside of the right side X lift mechanism. It is a VII-VII arrow line view of FIG. It is a perspective view of a separation detection mechanism. It is a schematic diagram of the motor drive circuit of a gantry raising / lowering apparatus. It is a side view showing the conventional frame raising / lowering apparatus.

  Hereinafter, based on FIGS. 1-9, the gantry raising / lowering apparatus which concerns on Embodiment 1 of this invention is demonstrated. The gantry lifting device according to the present embodiment is a device that lifts and lowers a platform used in a level difference canceling machine that eliminates a level difference. Here, front and rear, right and left, and up and down shown in the figure correspond to front and rear, right and left and up and down in the level difference canceller.

<About the outline of the level difference canceller 10>
As shown in FIG. 1, the level difference canceling machine 10 is configured so that a user of a wheelchair K (wheelchair user) is, for example, between an entrance floor FH at a high position and a road surface FL at a position lower than the entrance floor FH. It is an apparatus for enabling to move the step part. The level difference canceling machine 10 includes a horizontal platform 20 on which a wheelchair user can get on while sitting on the wheelchair K, a lifting device 30 (see FIGS. 2 and 3) for raising and lowering the platform 20, and the platform 20. It is comprised from the wheelchair slope 4 etc. which are used when it exists in a lower limit position.

  The platform 20 is formed in a rectangular shape that is long in the front-rear direction, and, as shown in FIG. 1, square cylindrical columns 22 are erected at the positions of the four corners. And the safety fence 23 of the upper and lower two steps | paragraphs is provided between the support | pillar 22 of the rear end right and left of the platform 20, and between the support | pillar 22 of the front end right side and the rear end right side. In addition, the platform 20 is provided with a first entrance 22a for moving between the platform 20 and the wheelchair slope 4 (road surface FL) between the right and left support columns 22 at the front end. Between the left column 22, a second entrance 22 b is provided for going back and forth between the platform 20 and the entrance floor FH.

<About the lifting device 30 of the platform 20>
The lifting device 30 of the platform 20 is a device that lifts and lowers the platform 20 in a horizontal state, and is installed on the lower side of the platform 20 as shown in FIGS. As shown in FIG. 1, the lifting device 30 of the platform 20 is covered with a shutter member 20 s that can be deformed in the vertical direction. As shown in FIG. 2, the lifting device 30 of the platform 20 includes a square frame-shaped base member 30b fixed on the road surface FL, and a pair of left and right X lift mechanisms provided on the left and right sides of the base member 30b. 31. The pair of left and right X lift mechanisms 31 is configured by connecting a first lift arm 33 and a second lift arm 34 at a center position of each other so as to be relatively rotatable in the vertical direction. That is, the first lift arm 33 and the second lift arm 34 of the X lift mechanism 31 can be rotated relative to each other in the standing direction or the lying down direction with the connection center C as the center. Here, the first lift arm 33 is overlapped with the second lift arm 34 from the outside in the width direction (left-right direction) of the base member 30b.

  As shown in FIGS. 2 and 3, the lower ends of the first lift arms 33 constituting the left and right X lift mechanisms 31 can be turned up and down by the first connecting pins 33p with respect to the left and right front portions of the base member 30b. It is connected in the state. A wheel 33r is attached to the upper end of the first lift arm 33, and the wheel 33r is fitted in a rollable manner on a guide rail 20m extending in the front-rear direction along the left and right edges of the platform 20. Match. As shown in FIGS. 2 and 3, the upper ends of the second lift arms 34 constituting the left and right X lift mechanisms 31 can be turned up and down by the second connecting pins 34 p with respect to the left and right front portions of the platform 20. Linked in state. A wheel 34r is mounted on the lower end of the second lift arm 34, and the wheel 34r can roll on a guide rail 30m extending in the front-rear direction along the left and right edges of the base member 30b. It is mated. For this reason, when the first lift arm 33 and the second lift arm 34 of the left and right X lift mechanisms 31 are relatively rotated in the standing direction, the platform 20 is raised in a horizontal state and is relatively rotated in the lying down direction. Thus, the platform 20 descends in a horizontal state.

  As shown in FIG. 3, the first lift arm 33 located on the upper rear side with respect to the connection center C of the first lift arm 33 and the second lift arm 34 has an upper cam surface 33c in a state of bulging rearward and downward. Is formed. In addition, a lower cam surface 34c is formed on the second lift arm 34 located on the lower rear side with respect to the connection center C of the first lift arm 33 and the second lift arm 34 in a state of bulging rearward and upward. Yes. The outer peripheral surface of the roller 41 of the drive mechanism 40 is sandwiched from above and below between the lower cam surface 34 c of the second lift arm 34 and the upper cam surface 33 c of the first lift arm 33.

<About the drive mechanism 40>
The drive mechanism 40 is a mechanism that relatively rotates the first lift arm 33 and the second lift arm 34 of the pair of left and right X lift mechanisms 31 around the connection center C in the standing direction or the lying down direction. As shown in FIG. 2, the drive mechanism 40 includes a pair of left and right rollers 41, a roller bracket 47 that supports the pair of left and right rollers 41, a motor bracket 43 k that supports the pair of left and right motors 43, and a pair of left and right ball screws 45. , And a ball nut 46.

  As shown in FIG. 2, the roller 41 is rotatably mounted at both left and right positions of the roller bracket 47 so that the axis of the roller 41 extends in the left-right direction of the base member 30b. As shown in FIGS. 4 to 7, the roller 41 has a right outer peripheral surface 411 on which the upper cam surface 33c of the first lift arm 33 abuts from above and a lower cam surface 34c of the second lift arm 34 from below. The left outer peripheral surface 412 that is in contact with the outer peripheral surface 412 is formed in a state of being separated by a certain dimension in the axial direction (left-right direction). As shown in FIG. 5, a ring-shaped partition ring 414 is provided between the right outer peripheral surface 411 and the left outer peripheral surface 412 of the roller 41. In addition, a detachment preventing ring 416 having the same diameter as the partition ring 414 is provided outside the right outer peripheral surface 411 of the roller 41. That is, the upper cam surface 33c of the first lift arm 33 is located above the right outer peripheral surface 411 of the roller 41 in a state inserted between the separation prevention ring 416 and the partition ring 414 of the roller 41, as shown in FIG. Will come into contact. Further, the lower cam surface 34 c of the second lift arm 34 comes into contact with the left outer peripheral surface 412 of the roller 41 from below while being inserted between the partition ring 414 of the roller 41 and the roller bracket 47.

  As shown in FIG. 2 and the like, the roller bracket 47 is a square frame-shaped bracket that is long in the left-right direction of the base member 30b, and the left and right rollers 41 are provided on the outer side of the left end surface and the outer side of the right end surface of the roller bracket 47. It is rotatably mounted. In addition, left and right ball nuts 46 are respectively attached in the vicinity of the left and right rollers 41 on the inner side of the left end surface and the inner side of the right end surface of the roller bracket 47. The left and right ball nuts 46 are positioned so that the axis of the ball nut 46 extends in the front-rear direction of the base member 30b. A ball screw 45 is screwed to each ball nut 46. Further, the front end portions of the left and right ball screws 45 are connected to the rotation shafts (not shown) of the left and right motors 43 as shown in FIG. The left and right motors 43 are attached to a square frame-shaped motor bracket 43k that is long in the left-right direction. As shown in FIGS. 2 and 3, the motor bracket 43 k is provided on the opposite side of the roller bracket 47 across the connection center C of the left and right X lift mechanisms 31.

  With the above configuration, when the left and right motors 43 rotate in the forward direction, the roller bracket 47 approaches the motor bracket 43k by the screwing action of the left and right ball screws 45 and the ball nuts 46, and the left and right rollers 41 It approaches the connection center C of the X lift mechanism 31. Thereby, as shown in FIG. 3, the roller 41 pushes the upper cam surface 33c of the first lift arm 33 and the lower cam surface 34c of the second lift arm 34 up and down like a wedge. That is, the upper cam surface 33c of the first lift arm 33 is pushed up with respect to the lower cam surface 34c of the second lift arm 34 by the roller 41, and the first lift arm 33 and the second lift arm 34 rotate relative to each other in the standing direction. Move. Thereby, the platform 20 comes to rise in a horizontal state.

  When the motor 43 rotates in the reverse direction, the roller bracket 47 is separated from the motor bracket 43 k by the screwing action of the ball screw 45 and the ball nut 46, and the roller 41 is separated from the connection center C of the X lift mechanism 31. As a result, the first lift arm 33 and the second lift arm 34 relatively rotate in the lying down direction following the roller 41 due to the weight of the platform 20, and the platform 20 is lowered in a horizontal state.

<About the separation detection mechanism 50>
During the lowering of the platform 20, the rotation of the first lift arm 33 and the second lift arm 34 may be stopped due to foreign matters or the like. In this state, when the drive of the motor 43 is continued, the roller 41 moves down along the lower cam surface 34 c of the second lift arm 34 by moving away from the connection center C of the X lift mechanism 31. As a result, the upper cam surface 33 c of the first lift arm 33 is separated from the right outer peripheral surface 411 of the roller 41. The separation detection mechanism 50 is a mechanism that detects that the upper cam surface 33 c of the first lift arm 33 is separated from the right outer peripheral surface 411 of the roller 41.

  The separation detection mechanism 50 determines that the upper cam surface 33 c of the first lift arm 33 is separated from the right outer peripheral surface 411 of the roller 41 when the first lift arm 33 is not present at a predetermined position with respect to the roller 41. As shown in FIGS. 4 to 7 and the like, the separation detection mechanism 50 includes a detection mechanism base 52 coupled to the roller bracket 47 of the drive mechanism 40, a moving cam 53 attached to the detection mechanism base 52, and a limit switch 57. And.

  The moving cam 53 is a pendulum-like cam configured to be able to contact the side surface of the first lift arm 33 at a predetermined position with respect to the roller 41. As shown in FIGS. 5, 6, and 8, the moving cam 53 is formed in a substantially fan shape. A portion of the moving cam 53 corresponding to the main part of the fan is connected to the detection mechanism pedestal 52 so as to be rotatable in the left-right direction by a connecting pin 52p. That is, the moving cam 53 is configured to be able to reciprocate on an arc centered on the connecting pin 52p.

  The right end of the moving cam 53 is provided with a pressing portion 53p that contacts the side surface of the first lift arm 33 and presses the side surface. Further, a striker portion 53 s that presses the operating lever 57 r of the limit switch 57 is provided at the left end portion of the moving cam 53. Further, around the connecting pin 52p of the moving cam 53, a coil spring 55 biased in a direction in which the moving cam 53 is pressed against the side surface of the first lift arm 33, that is, in a direction in which the moving cam 53 is rotated to the left is mounted. Has been. That is, the moving cam 53 corresponds to the moving member of the present invention, and the coil spring 55 corresponds to the elastic body of the present invention.

  When the first lift arm 33 does not exist at a predetermined position with respect to the roller 41, the pressing portion 53p of the moving cam 53 does not contact the side surface of the first lift arm 33 as shown in FIG. Therefore, the movable cam 53 is held at the left rotation limit position by the spring force of the coil spring 55. Thus, the striker portion 53s of the moving cam 53 does not press the operating lever 57r of the limit switch 57, and the operating lever 57r is returned to the original position. In this state, the contact 57s (see FIG. 9) of the limit switch 57 is turned off.

  When the first lift arm 33 is present at a predetermined position with respect to the roller 41, as shown in FIGS. 4 and 6, the pressing portion 53p of the moving cam 53 contacts the side surface of the first lift arm 33, and the moving cam 53 is stopped from rotating counterclockwise against the spring force of the coil spring 55. Accordingly, the striker portion 53s of the moving cam 53 is held in a state where the operating lever 57r of the limit switch 57 is pressed. That is, the operating lever 57r of the limit switch 57 is pushed from the original position, and the contact 57s of the limit switch 57 is turned on as shown in FIG. For this reason, when the upper cam surface 33c of the first lift arm 33 is in contact with the right outer peripheral surface 411 of the roller 41, the contact 57s of the limit switch 57 is always on.

  As shown in the schematic diagram of FIG. 9, the motor start circuit 60 that drives the motor 43 includes a start switch SW for causing the motor 43 to rotate forward (up), reverse (down), and stop. A contact 57 s of the limit switch 57 is connected in series to a power source negative line connecting the start switch SW and the motor 43. Therefore, when the upper cam surface 33c of the first lift arm 33 is separated from the right outer peripheral surface 411 of the roller 41 (when the first lift arm 33 does not exist at a predetermined position with respect to the roller 41), the contact of the limit switch 57 57s is turned off, the circuit is opened, and the motor 43 is stopped. That is, the motor starting circuit 60 corresponds to the changing means of the present invention.

<About the operation of the level difference canceller 10>
Next, the operation of the level difference canceling machine 10 will be described. First, a case where a wheelchair user sitting on the wheelchair K is moved from the road surface FL to the entrance floor FH will be described. In a state where the platform 20 is at the lower limit position, the platform 20 is held at a position continuous with the wheelchair slope 4 positioned on the front side. In this state, the upper cam surface 33c of the first lift arm 33 is in contact with the right outer peripheral surface 411 of the roller 41 as shown in FIGS. The pressing portion 53 p is in contact with the side surface of the first lift arm 33. Thereby, the striker portion 53s of the moving cam 53 presses the operating lever 57r of the limit switch 57, and the contact 57s of the limit switch 57 is in the ON state as shown in FIG.

  Therefore, when the wheelchair user who has moved from the wheelchair slope 4 onto the platform 20 operates the activation switch SW in the upward direction, the motor 43 rotates in the forward direction. As a result, the roller bracket 47 approaches the motor bracket 43 k by the screwing action of the ball screw 45 and the ball nut 46, and the roller 41 approaches the connection center C of the X lift mechanism 31. Thereby, as shown in FIG. 3, the roller 41 pushes the upper cam surface 33c of the first lift arm 33 and the lower cam surface 34c of the second lift arm 34 up and down like a wedge. That is, the upper cam surface 33c of the first lift arm 33 is pushed up with respect to the lower cam surface 34c of the second lift arm 34 by the roller 41, and the first lift arm 33 and the second lift arm 34 rotate relative to each other in the standing direction. Move. Thereby, the platform 20 comes to rise in a horizontal state. The motor 43 stops when the platform 20 rises to the entrance floor FH.

  Further, in order to lower the platform 20 from the position of the entrance floor FH, the start switch SW is operated in the downward direction to rotate the motor 43 in the reverse direction. Thereby, the roller bracket 47 is separated from the motor bracket 43 k by the screwing action of the ball screw 45 and the ball nut 46, and the roller 41 is separated from the connection center C of the X lift mechanism 31. As a result, the first lift arm 33 and the second lift arm 34 relatively rotate in the lying down direction following the roller 41 due to the weight of the platform 20, and the platform 20 is lowered in a horizontal state.

  Next, a case will be described in which the first lift arm 33 and the second lift arm 34 stop rotating in the lying down direction due to foreign object biting or the like while the platform 20 is descending. In this state, when the drive of the motor 43 is continued, the roller 41 moves down along the lower cam surface 34 c of the second lift arm 34 by moving away from the connection center C of the X lift mechanism 31. Thus, when the upper cam surface 33c of the first lift arm 33 is separated from the right outer peripheral surface 411 of the roller 41, the side surface of the first lift arm 33 is separated and the moving cam 53 of the detection mechanism 50 is pressed as shown in FIG. It comes away from the part 53p. As a result, the moving cam 53 of the separation detecting mechanism 50 rotates counterclockwise by the spring force of the coil spring 55, and the striker portion 53s of the moving cam 53 does not press the operating lever 57r of the limit switch 57. As a result, the operating lever 57r of the limit switch 57 is returned to the original position, and the contact 57s of the limit switch 57 is turned off. As a result, the motor drive circuit 60 is opened and the motor 43 is stopped. That is, the platform 20 is not greatly lowered by its own weight.

<Advantages of the lifting device 30 of the platform according to this embodiment>
According to the platform lifting / lowering device 30 according to the present embodiment, for example, while the platform 20 is lowered, the lowering of the platform 20 stops due to the influence of foreign matter or the like, and the upper cam surface 33c of the first lift arm 33 that presses the roller 41 from above. When separated from the roller 41, the separation detection mechanism 50 detects the separation between the roller 41 and the upper cam surface 33c of the first lift arm 33. Thereby, the limit switch 57 operates and the motor 43 of the drive mechanism 40 stops. As a result, the motor 43 of the drive mechanism 40 does not continue to operate in a state where the roller 41 and the upper cam surface 33c of the first lift arm 33 are separated from each other, and the platform 20 does not drop greatly.

  Further, the separation detecting mechanism 50 detects whether or not the first lift arm 33 is present at a predetermined position with respect to the roller 41, and when the first lift arm 33 is not present at the predetermined position, the upper cam of the first lift arm 33 is detected. It is determined that the surface 33c is separated from the roller 41. Thus, since it is not the structure which detects directly the contact or separation of the upper cam surface 33c of the 1st lift arm 33 with respect to the roller 41, the freedom degree of the installation position of the separation detection mechanism 50 becomes high. Further, the presence or absence of the upper cam surface 33c of the first lift arm 33 can be reliably detected with a simple configuration. Further, since the moving cam 53 (moving member) of the separation detecting mechanism 50 is formed in a pendulum shape, the moving cam 53 is damaged when the moving cam 53 contacts or separates from the first lift arm 33. It becomes difficult to do.

<Example of change>
Here, the present invention is not limited to the above-described embodiment, and can be modified without departing from the gist of the present invention. For example, in the present embodiment, the separation detection mechanism 50 including the moving cam 53 and the limit switch 57 is illustrated. However, instead of the moving cam 53 and the limit switch 57, for example, a photoelectric switch or the like can be used to detect whether or not the first lift arm 33 is present at a predetermined position with respect to the roller 41. Further, in the present embodiment, an example is shown in which when the separation between the roller 41 and the upper cam surface 33c of the first lift arm 33 is detected by the separation detection mechanism 50, the motor 43 of the drive mechanism 40 is stopped by the limit switch 57. It was. However, instead of stopping the motor 43, the rotational speed of the motor 43 can be switched to a low speed. Further, in the present embodiment, the example in which the present invention is applied to the lifting device 30 of the platform 20 of the level difference canceller 10 has been described. However, the present invention can also be applied to a lifting device for a gantry that lifts and lowers a vehicle or the like. .

20 .... Platform (ceiling mount)
30 ... Elevating device 31 ... X lift mechanism 33 ... First lift arm 33c ... Upper cam surface 34 ... Second lift arm 34c ... Lower cam surface 40 ... .... Drive mechanism 41 ... Roller 411 ... Right outer peripheral surface 412 ... Left outer peripheral surface 43 ... Motor 47 ... Roller bracket (bracket)
50 ··· Separation detection mechanism 53 ··· Moving cam (moving member)
53p ... Pressing part 55 ... Coil spring (elastic body)
57... Limit switch (switch)
57r ... actuating lever 57s ... contact 60 ... motor starting circuit (changing means)

Claims (5)

A ceiling installed on the first lift arm and the second lift arm, the first lift arm and the second lift arm being connected to each other so as to be relatively rotatable in the standing direction or the lying down direction in a state of crossing the X shape. A gantry lifting device that lifts and lowers the ceiling gantry in a horizontal state by relatively rotating the first lift arm and the second lift arm in the standing direction or the lying down direction,
A roller whose outer peripheral surface is sandwiched from above and below by the first lift arm and the second lift arm;
By moving the roller toward or away from the connection center of the first lift arm and the second lift arm, the first lift arm and the second lift arm are rotated relative to each other in a standing direction or a lying direction. A drive mechanism
A separation detecting mechanism capable of detecting that the first lift arm has separated from the outer peripheral surface of the roller;
Changing means for changing the operation of the drive mechanism when it is detected by the separation detection mechanism that the first lift arm is separated from the outer peripheral surface of the roller;
A platform lifting device. The gantry lifting device according to claim 1,
The separation detection mechanism detects whether or not the first lift arm is at a predetermined position with respect to the roller, and when the first lift arm is not at the predetermined position, the first lift arm is A gantry lifting device that determines that it is away from the outer peripheral surface. The gantry lifting device according to claim 2,
The separation detection mechanism is attached to a bracket that supports the roller and is configured to reciprocate within a certain range; an elastic body that urges the movement member in one direction; and With a switch to detect movement,
When the first lift arm is in a predetermined position with respect to the roller, the moving member comes into contact with the first lift arm and stops at an intermediate position of the moving range, and when the first lift arm is not in the predetermined position. A gantry elevating device configured such that the moving member does not stop at an intermediate position in the moving range. The gantry lifting device according to claim 3,
The moving member is connected in a state in which the upper end of the moving member is rotatable with respect to the bracket,
The gantry raising / lowering device is configured such that the moving member can reciprocate on an arc centering on a connection portion with the bracket. The gantry lifting device according to any one of claims 1 to 4,
The separation detection mechanism is a gantry lifting device provided between a connection center of the first lift arm and the second lift arm and the roller.

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