JP5352015B2 - Fine adjustment return mechanism - Google Patents

Description

  The present invention relates to a fine adjustment return mechanism that collectively returns the yarn tension fine adjustment means for finely adjusting the yarn clamping pressure of each yarn tensioner of an overlock sewing machine.

  In a sewing machine that uses a plurality of sewing threads such as an overlock sewing machine, it is necessary to change the tension applied to each sewing thread in accordance with the type of seam (overlock sewing, full winding sewing, decorative sewing, etc.). In addition, models have been developed that can change the tension applied to each sewing thread in a batch with a single operation dial. However, when actually sewing, there may be a slight difference in the thickness of the fabric, etc. Normally, a fine adjustment lever that can finely adjust the tension applied to each sewing thread is equipped as a thread tension fine adjustment means. doing.

  For example, in Patent Document 1, a moving body that moves in conjunction with the yarn tension micro-adjustment means is defined as a swinging body composed of two sides arranged opposite to each other with the moving body interposed therebetween, and the two sides of the swinging body are set in the origin direction. An adjustment knob fixed position returning device for a thread tensioner that returns a moving body to the origin by moving the moving body to the home position is disclosed. Patent Document 2 discloses an adjustment operation device for a thread tensioner that returns a thread tension micro-adjustment means other than the origin to the origin position in conjunction with a pulling operation of the adjustment dial.

Japanese Patent No. 2686188 Japanese Patent No. 3444414

  However, the adjustment knob fixed position return device for the thread tensioner disclosed in Patent Document 1 needs to be provided with a biasing member or the like for adjusting the movement of the swinging body, and can be configured so that the two sides of the swinging body are equally distributed. There is a problem that it is difficult to control the moving body to move, and there is no guarantee that the moving body is accurately returned to the origin by moving the two sides of the oscillating body in the direction of the origin. Therefore, as the number of times increases, the error between the return position and the origin position may accumulate, and in some cases, the tension applied to each sewing thread cannot be finely adjusted. In this case, in order to confirm whether or not the thread tensioner has accurately returned the moving body to the origin, it is necessary to perform trial sewing after all, and there remains a problem that the sewing thread and the workpiece are unnecessarily consumed. Has been.

  In Patent Document 2, although the thread tensioner can be accurately returned to the origin position, it is necessary to correctly process the conversion positioning plate, and there is a problem that it is difficult to reduce the manufacturing cost.

  The present invention has been made in view of such circumstances, and even with a simple structure, the thread tension fine adjustment means for finely adjusting the thread clamping pressure of the thread tension tray can be reliably returned to the origin position. An object is to provide a fine adjustment return mechanism of an overlock sewing machine.

In order to solve the above problem, the fine adjustment return mechanism according to the first aspect of the present invention includes a thread tension setting unit that collectively sets a thread clamping pressure of a plurality of thread tension plates to a desired pressure, and other than the origin position. Thread tension fine adjustment means capable of finely adjusting the thread clamping pressure set by rotating the position to the position with an adjustment lever , respectively, and rotating in conjunction with the thread tension fine adjustment means; A rotating body having one protrusion on one surface, and two sets of slider crank mechanisms facing each other surrounding the protrusion, the pivot points of the cranks of the two sets of slider crank mechanisms and the rotation center of the rotating body Are arranged so as to coincide with each other, and a slider common to the two sets of the slider crank mechanism is disposed from the rotation center of the rotating body so that the projection is sandwiched between the cranks by the setting operation of the yarn tension setting means. , Wherein the serial adjusting lever are so as to return in a direction towards to the home position.

In the first invention, the thread tension setting means for collectively setting the thread clamping pressures of the plurality of thread tension plates to a desired pressure, and the thread clamping pressure set by rotating from the origin position to other positions. Thread tension fine adjustment means that can be finely adjusted with an adjustment lever . A rotary body that rotates in conjunction with the yarn tension fine adjustment means and has one protrusion on one surface, and two sets of slider crank mechanisms that face each other and surround the protrusion, and two sets of the slider crank mechanisms The crank fulcrum of the crankshaft is arranged so that the rotation center of the rotating body coincides. By the setting operation of the thread tension setting means, the slider common to the two sets of slider crank mechanisms is returned from the rotation center of the rotating body so that the adjusting lever is directed toward the origin position so as to sandwich the protrusion with the crank. Thus, every time the thread clamping pressure of the plurality of thread tension plates is set to a desired pressure by the thread tension setting means, the slider is moved in the direction from the center of rotation to the origin position, and the protrusion of the rotating body is moved. It is sandwiched between cranks. Since the crank fulcrum is the center of rotation of the rotating body and the lengths of the cranks are equal, the rotating position of the rotating body is constant, and the protrusion of the rotating body can be reliably moved to the origin position. It is possible to accurately return the tension fine adjustment means to the origin position.

  Further, in the fine adjustment return mechanism according to the second invention, in the first invention, the yarn tension setting means changes the set yarn clamping pressure of the plurality of thread tension plates by rotating the end face cam. The slider is returned in a direction from the rotation center of the rotating body to the origin position at a position where the shape of the end face cam changes.

  In the second invention, the yarn tension setting means changes the set yarn clamping pressure of the plurality of yarn tension plates by rotating the end face cam. By returning the slider from the rotation center of the rotating body toward the origin position at the position where the shape of the end cam changes, the thread tension setting means is returned to the origin position when a new thread clamping pressure is set. Therefore, fine adjustment can be surely performed.

  According to the present invention, each time the thread clamping pressure of the plurality of thread tension plates is collectively set to a desired pressure by the thread tension setting means, the slider is moved in the direction from the center of rotation toward the origin position. The protruding part of the body is sandwiched between the cranks. Since the crank fulcrum is the center of rotation of the rotating body and the lengths of the cranks are equal, the rotating position of the rotating body is constant, and the protrusion of the rotating body can be reliably moved to the origin position. It is possible to accurately return the tension fine adjustment means to the origin position.

It is a front view which shows the structure of the thread tension device of the overlock sewing machine which concerns on embodiment of this invention. It is a schematic diagram which shows the structure of the connection mechanism of the operation dial of the thread tensioner of the overlock sewing machine which concerns on embodiment of this invention, and a thread tension adjustment mechanism. It is the top view and front view which show the structure of the thread tension adjusting mechanism of the thread tension device of the overlock sewing machine which concerns on embodiment of this invention. It is the schematic block diagram seen from the right of the fine adjustment return mechanism of the thread tension adjustment mechanism of the thread tensioner of the overlock sewing machine which concerns on embodiment of this invention. It is a schematic diagram for demonstrating the principle of the fine adjustment return mechanism of the thread tension adjustment mechanism of the thread tension device of the overlock sewing machine which concerns on embodiment of this invention.

  Hereinafter, a thread tension device of an overlock sewing machine according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view showing a configuration of a thread tensioner of an overlock sewing machine according to an embodiment of the present invention.

  As shown in FIG. 1, the thread tension device 1 of the overlock sewing machine according to the present embodiment includes a thread tension adjusting mechanism 2, 2, 2 for left needle, right needle, upper looper, and lower looper. 2 on the same axis. The thread tension adjusting mechanisms 2, 2, 2, 2 are sandwiched between the support plate 4 and the support plate 5 and can be rotated (moved) in conjunction with the operation dial 3. The operation dial 3 collectively sets the thread clamping pressure of the thread tension plate to a desired pressure. That is, each thread tension adjusting mechanism 2 can collectively adjust the thread clamping pressure in the plurality of thread tension trays 21 by rotating the operation dial 3 from the origin position to other positions.

  FIG. 2 is a schematic diagram showing a configuration of a connection mechanism between the operation dial 3 and the thread tension adjusting mechanism 2 of the thread tension device 1 of the overlock sewing machine according to the embodiment of the present invention. As shown in FIG. 2, a selection gear 31 is connected to the operation dial 3, the selection gear 31 is connected to the interlocking gear 32, and the interlocking gear 32 is connected to the thread tension adjusting mechanism 2 via an intermediate gear 33b. It is.

  FIG. 3 is a plan view and a front view showing the configuration of the thread tension adjusting mechanism 2 of the thread tensioner 1 of the overlock sewing machine according to the embodiment of the present invention. 3A is a plan view of the thread tension adjusting mechanism 2 as viewed from above the overlock sewing machine, and FIG. 3B is a view of the thread tension adjusting mechanism 2 as viewed from the side where the user operates the overlock sewing machine. A front view is shown.

  As shown in FIG. 3, the thread tension adjusting mechanism 2 has a thread tension tray 21 that adjusts the thread clamping pressure for clamping the sewing thread, crimped to one end side. The thread tension tray 21 is composed of symmetrical plates 21a and 21b that are opposed to each other to sandwich the sewing thread, and the other tray 21b is pressure-bonded to one tray 21a by an urging force. is there.

  A base plate 22 is provided on the other end side of the thread tension adjusting mechanism 2, and the base plate 22 is provided with a protrusion 23 that controls the operation of the end face cam 24. The shape of the end face cam 24 is changed for each thread tension adjusting mechanism 2, and is rotated via the selection gear 31, the interlocking gear 32, and the intermediate gear 33 b connected by the rotation of the operation dial 3, and connected to the intermediate gear 33 b. The end face cam 24 of the thread tension adjusting mechanism 2 is rotated.

  As the end face cam 24 rotates, the position of contact with the protrusion 23 varies, and the position of the end face cam 24 along the rotation axis according to the position of contact with the protrusion 23, that is, in the direction of the arrow in FIG. Move left and right). In accordance with the movement of the end face cam 24, the urging force of the compression spring (biasing member) 25 to the thread tension plate presser gear 26 and the thread tension plate presser 27 that can move along the rotation axis without rotating is applied. fluctuate. That is, the end face cam 24 moves to the left as the end face of the end face cam 24 and the projection 23 come into contact with each other at a shallow position on the end face of the end face cam 24, and the thread tension plate presser of the compression spring (biasing member) 25 is moved. The urging force to the gear 26 and the thread tension plate presser 27 is increased. Accordingly, since the pressing force with which the thread tension plate presser 27 presses the other tray 21b of the thread tension tray 21 against the one tray 21a increases, the thread clamping pressure for sandwiching the sewing thread in the thread tension tray 21 increases.

  On the other hand, the end face cam 24 moves to the right as the end face of the end face cam 24 and the protrusion 23 come into contact with each other at a deeper position on the end face of the end face cam 24, and the thread tension plate presser of the compression spring (biasing member) 25 is moved. The biasing force to the gear 26 and the thread tension plate presser 27 is reduced. Accordingly, since the pressing force with which the thread tension tray presser 27 presses the other tray 21b of the thread tension tray 21 against the one tray 21a is reduced, the thread clamping pressure for clamping the sewing thread in the thread tension tray 21 is reduced. By designing the shape of the end face cam 24 corresponding to the rotation of the operation dial 3, the rotation of the operation dial 3 allows the plurality of thread tension plates 21, 21, 21, 21 to be configured with two plates. The thread clamping pressure for clamping the sewing thread can be collectively adjusted to a desired pressure.

  In addition to the adjustment in a lump, the thread clamping pressure for clamping the sewing thread in the thread tension tray 21 can be finely adjusted. In the present embodiment, the intermediate gear 33a and the intermediate gear 33b are gears that rotate (operate) separately and independently, and only have the same rotation axis. When finely adjusting the thread clamping pressure for clamping the sewing thread in the thread tension tray 21, only the thread tension tray presser gear 26 is rotated by rotating the adjustment gear 30.

  A thread is formed on the inner diameter of the thread tension plate presser gear 26 and is screwed with a thread formed on the surface of the connecting shaft 271 connected to the thread tension plate presser 27. That is, a female screw is formed on the inner diameter of the thread tension plate presser gear 26, and a male screw is formed on the surface of the connecting shaft 271 of the thread tension plate presser 27. By rotating the thread tension tray presser gear 26, the position of the thread tension tray presser gear 26 moves in the direction of the connecting shaft 271 (left and right direction). As a result, the biasing force of the compression spring (biasing member) 25 to the thread tension plate presser 27 can be increased or decreased.

  FIG. 4 is a schematic configuration diagram viewed from the right of the fine adjustment return mechanism of the thread tension adjusting mechanism 2 of the thread tension device 1 of the overlock sewing machine according to the embodiment of the present invention. As shown in FIG. 4, the adjustment gear (rotary body) 30 and the adjustment lever (thread tension fine adjustment means) 30a are integrally formed and rotate in conjunction with each other. When finely adjusting the thread clamping pressure for clamping the sewing thread in the thread tension tray 21, the intermediate gear 33a is rotated by rotating the adjustment lever 30a in the vertical (arrow) direction, and the thread tension tray presser gear 26 is rotated. To do. As the thread tension plate presser gear 26 rotates, the position of the thread tension plate presser gear 26 moves in the direction of the connecting shaft 271 (left and right direction) as shown in FIG. 3, and the thread tension of the compression spring (biasing member) 25 is increased. The urging force to the plate presser 27 is increased or decreased.

  The selection gear 31 connected to the operation dial 3 includes a rotating cam 311 that rotates coaxially. The rotating cam 311 corresponds to the variation in the depth of the position where the end face of the end face cam 24 of the thread tension adjusting mechanism 2 and the protrusion 23 come into contact, and the position where the end face of the end face cam 24 and the protrusion 23 come into contact. Each time the depth of the thread fluctuates and the urging force to the thread tension plate presser 27 increases or decreases, the fine adjustment return claw 41 has a shape (for example, a star shape) that can be engaged.

  The fine adjustment return claw 41 is formed integrally with the fine adjustment return arm 42, and can mesh with the star-shaped valley of the rotating cam 311. In other words, when the operation dial 3 is rotated and the thread clamping pressure for clamping the sewing thread in the thread tension plates 21 of the plurality of thread tension adjusting mechanisms 2, 2, 2, 2 is collectively adjusted, fine adjustment is restored. The claw 41 passes through the star-shaped peak of the rotating cam 311. When the fine adjustment return claw 41 passes through the star-shaped peak of the rotating cam 311, the fine adjustment return claw 41 moves to the right in FIG. 4 (rotates counterclockwise), and the fine adjustment return claw 41 The end 422 of the fine adjustment return arm 42 is pulled out in the lower right direction (arrow direction) in FIG.

  One end of two fine adjustment return links 43, 43 is rotatably connected to the end 422 of the fine adjustment return arm 42, and the other end of the fine adjustment return links 43, 43 is connected to the fine adjustment return. One end of each of the plates 44 and 44 is connected so as to be rotatable. The other ends of the fine adjustment return plates 44 and 44 are connected to the rotation center of the adjustment gear (rotating body) 30 so as to be rotatable.

  That is, the mechanism (fine adjustment return mechanism) from the rotation center of the adjustment gear (rotating body) 30 to the end 422 of the fine adjustment return arm 42 causes the end 422 of the fine adjustment return arm 42 to function as a slider. Two sets of slider crank mechanisms which are composed of a fine adjustment return link 43 and a fine adjustment return plate (crank) 44 are opposed to each other.

  One protrusion 30 b is provided on one surface of the adjustment gear 30 so as to be sandwiched between the two fine adjustment return plates 44, 44. When the end 422 of the fine adjustment return arm 42 that functions as a slider is pulled out in the lower right direction (arrow direction) in FIG. 4, the fine adjustment return links 43 and 43 are similarly pulled out in the lower right direction, The angle formed by the fine adjustment return plates 44, 44 becomes narrower. Accordingly, the protrusion 30b is sandwiched between the two fine adjustment return plates (cranks) 44, 44, and the adjustment gear 30 rotates to a certain position.

  Since the shaft fulcrum of the two fine adjustment return plates 44, 44 and the rotation center of the adjustment gear (rotating body) 30 are aligned, the lengths of the fine adjustment return links 43, 43 are equal. The adjustment gear 30 rotates to a certain position. Therefore, by setting the fixed position as the origin position of the adjusting lever 30a, the operation dial 3 can be operated no matter how much the adjusting lever 30a is rotated in order to finely adjust the thread clamping pressure in the thread tension plate 21. Is rotated to collectively adjust the thread clamping pressure for clamping the sewing thread in each of the thread tension adjusting plates 21 of the plurality of thread tension adjusting mechanisms 2, 2, 2, 2, and the adjustment lever 30 a is returned to the origin position. Can be made.

  FIG. 5 is a schematic diagram for explaining the principle of the fine adjustment return mechanism of the thread tension adjusting mechanism 2 of the thread tension device 1 of the overlock sewing machine according to the embodiment of the present invention. As shown in FIG. 5A, when the adjustment lever 30a is rotated, one of the two fine adjustment return plates 44, 44 is pushed up by one protrusion 30b provided on one surface of the adjustment gear 30. When pushed down, the two fine adjustment return plates 44, 44 spread so as to form a certain angle. Therefore, the thread clamping pressure in the thread tension tray 21 can be finely adjusted for each thread tension tray 21 by the rotation of the adjustment lever 30a.

  When the operation dial 3 is rotated to collectively adjust the thread clamping pressure in the thread tension tray 21, the end 422 of the fine adjustment return arm 42 that functions as a slider is provided as shown in FIG. 5B. Pulled out in the lower right direction (arrow direction), the angle formed by the two fine adjustment return plates 44, 44 becomes narrower. Accordingly, the protrusion 30b is sandwiched between the two fine adjustment return plates (cranks) 44, 44, and the adjustment gear 30 rotates to a certain position.

  Since the shaft fulcrum of the two fine adjustment return plates 44, 44 and the rotation center of the adjustment gear (rotating body) 30 are aligned, the lengths of the fine adjustment return links 43, 43 are equal. The adjustment gear 30 rotates to a certain position. Therefore, by setting the fixed position as the origin position of the adjusting lever 30a, the operation dial 3 can be operated no matter how much the adjusting lever 30a is rotated in order to finely adjust the thread clamping pressure in the thread tension plate 21. Is rotated to collectively adjust the thread clamping pressure for clamping the sewing thread in each of the thread tension adjusting plates 21 of the plurality of thread tension adjusting mechanisms 2, 2, 2, 2, and the adjustment lever 30 a is returned to the origin position. Can be made.

  As described above, according to the present embodiment, the fine adjustment return arm is set every time the thread clamping pressures at the plurality of thread tension plates 21, 21, 21, 21 are collectively set to a desired pressure by the operation dial 3. 42, the end (slider) 422 of the adjustment gear 30 is moved in the direction from the rotation center of the adjustment gear 30 to the origin position, and the protrusion 30b of the adjustment gear (rotary body) 30 is located between the fine adjustment return plates (cranks) 44, 44. Sandwiched between. Since the shaft support point of the fine adjustment return plates 44 and 44 and the rotation center of the adjustment gear 30 are aligned with each other, and the lengths of the fine adjustment return links 43 and 43 are equal, the adjustment gear 30 reaches a certain position. By rotating, the protrusion 30b of the adjustment gear 30 can be reliably moved to the origin position, and the adjustment lever 30a can be accurately returned to the origin position.

  In addition, various modifications can be added to the above-described embodiment without departing from the spirit of the present invention.

1 Thread tension device 2 Thread tension adjustment mechanism 3 Operation dial (thread tension setting means)
21 Thread tension plate 23 Projection 24 End face cam 25 Compression spring (biasing member)
26 Thread tension plate presser gear 27 Thread tension plate presser 30 Adjustment gear (rotating body)
30a Adjusting lever (thread tension fine adjusting means)
30b Protrusion 33a, 33b Intermediate gear 42 Fine adjustment return arm 43 Fine adjustment return link 44 Fine adjustment return plate (crank)
422 end (slider)

Claims (2)

Thread tension setting means for collectively setting a thread clamping pressure of a plurality of thread tension plates to a desired pressure;
Thread tension fine adjustment means capable of finely adjusting the thread clamping pressure set by rotating from the origin position to the other position with an adjustment lever ;
A rotating body that rotates in conjunction with the thread tension fine adjustment means and has one protrusion on one surface;
Two sets of slider crank mechanisms that surround the protrusion and face each other,
The crank fulcrum of the two sets of the slider crank mechanism are arranged so that the rotation center of the rotating body coincides,
By the setting operation of the yarn tension setting means, a slider common to the two sets of the slider crank mechanism is sandwiched between the cranks so that the protrusion is sandwiched between the cranks, and the adjustment lever moves from the rotation center of the rotating body to the origin position. A fine adjustment return mechanism characterized by being returned in such a direction. The thread tension setting means is configured to change the thread clamping pressure of the plurality of thread tension plates set by rotating an end face cam,
2. The fine adjustment return mechanism according to claim 1, wherein the slider is returned in a direction from the rotation center of the rotating body toward the origin position at a position where the shape of the end face cam changes.

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