JPH084945Y2 - Overrun prevention device for feed cam in cycle sewing machine - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed cam overrun prevention device in a cycle sewing machine applied to boring and the like.

[0002]

2. Description of the Related Art First, a conventional feed cam overrun prevention device in the above-described cycle sewing machine will be described with reference to FIGS.

An overrun prevention device 1 for a feed cam in a cycle sewing machine of this type is supported by a frame (not shown), and an input shaft 2 having a drive pulley 3 fixed to one end thereof.
The rotary drive force of an electric motor or the like, which is a drive source (not shown), is transmitted to the drive pulley 3 of the input shaft 2 by a V belt or a timing belt.
Then, by rotating the drive pulley 3 in the direction of arrow A in FIG. 6, the input shaft 2 is rotated in the same direction, and the worm 4 which is the input side of the speed reducer and is fixed to the input shaft 2 at an appropriate position. The rotating force of the worm 4 that is configured to rotate in the rotation direction A and that is the input side of the reduction gear is transmitted to the worm wheel 5 that is the output side of the reduction gear, and in the direction of arrow B in FIG. The worm wheel 5 is adapted to rotate.

The worm wheel 5 is rotatably fitted to a horizontal shaft 6a supported by a bearing (not shown) so as to be rotatable relative to the horizontal shaft 6a by an appropriate position fixing means such as a retaining ring. A clutch collar 8 is fixed to the horizontal shaft 6a with a set screw 7. Then, the rotational force of the worm wheel 5 is transmitted to the clutch collar 8 via a substantially cylindrical one-way clutch spring 10 having one end engaged with an engagement hole 9 provided at an appropriate position of the worm wheel 5. It is being transmitted.

The one-way clutch spring 10 is applied so that it can be forcibly operated with the driving force of the sewing machine stopped during maintenance or the like.

The one-way clutch spring 10 is fitted around the outer periphery of the clutch collar 8 with a desired tightening margin, and when the worm wheel 5 rotates in the direction of arrow B in FIG. It is wound in the direction of. Then, when the worm wheel 5 rotates, the one-way clutch spring 10 gradually decreases in diameter from one end engaged with the worm wheel 5, and the sliding resistance with the clutch collar 8 increases, and the rotational driving force is increased. It can be transmitted to the clutch collar 8.

A spur gear 12a is provided at one end of the horizontal shaft 6a through a connecting collar 11 to the worm wheel 5a.
6 is arranged so as to rotate in the direction of arrow C in FIG. The spur gear 12a is meshed with a spur gear 12b fixed to one end of a horizontal shaft 6b arranged in parallel with the horizontal shaft 6a by a bearing (not shown). Gear 1
2b is rotated in the direction of arrow D in FIG.

Further, a screw gear 13a is fixed to the other end of the horizontal shaft 6b. This screw gear 13a
Is meshed with a screw gear 13b fixed to the upper side in FIG. 6, which is one end of the drive shaft 14 arranged vertically by a bearing (not shown), and the drive shaft 14 is rotated by the screw gear 13a. It is adapted to rotate in the direction of arrow E in FIG. A drive gear 17, which is a spur gear that meshes with a tooth portion 16 provided on the outer circumference of the feed cam 15, is fixed to the lower end, which is the other end of the drive shaft 14. The drive gear 17 causes the feed cam 15 to rotate in the direction of arrow F in FIG.

The feed cam 15 is formed in a substantially disc shape, and a through hole 18 provided in the shaft center portion is rotatably supported by a support shaft provided at an appropriate position of a frame (not shown). Are arranged. Further, a flat cam 19 or the like is formed on the upper surface in the drawing which is one surface of the feed cam 15 in the axial direction, and a groove cam for boring is formed on the lower surface which is the other surface of the feed cam 15 in the drawing. Various cams 20 are formed, and a feeding mechanism (not shown) is reciprocated.

The flat cam 19 is, as shown in FIG.
A desired step in the axial direction is provided on a plane projecting in an annular shape on the upper surface of the feed cam 15, and the step is connected by an inclined surface 21. Further, a bell crank-shaped needle swing control arm 22 rotatably supported by a horizontal support pin 22c is disposed above the plane cam 19, and the needle swing control arm 22 is almost free. A cylindrical roller 23 is rotatably disposed at the tip of the horizontal arm 22a extending in the horizontal direction. And this cylindrical roller 2
3 is in contact with the flat cam 19.

Further, the needle swing control arm 22 is urged at the distal end of the vertical arm 22b extending substantially vertically to rotate the needle swing control arm 22 clockwise in FIG. One end of a tension spring 24 is locked, and the cylindrical roller 23 is brought into contact with the flat cam 19 with a desired pressing force.

By the way, as shown in FIG. 8, when the sewing machine is stopped by a stop instruction, the cylindrical roller 23 is arranged so that the plane cam 19 of the feed cam 15 is inclined as shown in FIG. It stops at the position where it always contacts the surface 21. Therefore, the cylindrical roller 23 stops in a state of being in pressure contact with the inclined surface 21 of the flat cam 19, which provides a force for rotating the feed cam 15 in the direction indicated by arrow F in FIG. At this time, even if the rotation of the drive pulley 3 is stopped, the rotational force reversely transmitted from the feed cam 15 acts in the direction of expanding the diameter of the one-way clutch spring 10 to cause the worm wheel 5 to move.
One end engaged with is fixed and the other end is given rotation by the clutch collar 8 in the direction of arrow C shown in FIG. As a result, the clutch collar 8 rotates, and it is impossible to prevent the rotational force that is transmitted in reverse. Therefore, the feed cam 15 overruns and rotates in the direction indicated by the arrow F in FIG. As a result, the feeding operation and the like are performed even when the driving force of the sewing machine is stopped.

Therefore, conventionally, as shown in FIGS. 6 and 8, a groove 25 having a substantially semicircular cross section is formed in the circumferential direction of the outer peripheral surface of the feed cam 15, and a brake spring 26 is provided in the groove 25.
Thus, the brake band 27, which generates an appropriate frictional resistance when the feed cam 15 overruns, is arranged so as to always come in contact with a desired pressing force to prevent the feed cam 15 from overrunning.

[0014]

However, in the feed cam overrun prevention device 1 in the conventional cycle sewing machine described above, the feed cam 15 is always provided with the brake band 27 in order to prevent the feed cam 15 from overrunning. Must be abutted and therefore the feed cam 15
However, there is a problem in that a drive motor having a large capacity has to be applied, the transmission torque applied to each gear train increases, and the life of each gear is shortened.

Further, the brake band 27 and the feed cam 15
Is always in contact with the groove 25 of the brake band 27.
However, there is a problem in that the frictional resistance between the groove 25 formed on the feed cam 15 and the groove 25 decreases with the lapse of time, which is inevitable.

The present invention overcomes the above-mentioned problems in the prior art, and prevents the overrun of the feed cam with high reliability by a simple structure without applying a brake band. It is an object to provide a run prevention device.

[0017]

In order to achieve the above-mentioned object, a feed cam overrun prevention device in a cycle sewing machine according to the present invention is provided with a worm and a worm wheel for decelerating a rotational driving force of a driving source rotationally driven in one direction. And a one-way clutch for transmitting the rotational driving force of the worm wheel, which is the output side of the speed reducer, to the feed cam on the driven side, and the one-way clutch is driven by the driving side member and the driven side member. A side member, and one end of the driving side member is engaged with the worm wheel by a spring member biased in a direction of separating from the worm wheel so as to be freely accessible, and the other end and the driven side member. The driven member is fixed to the output shaft by meshing one end of the driven member with a tooth formed in a direction for transmitting the rotation output of the speed reducer to the feed cam. It is characterized in that which is formed by.

[0018]

According to the feed cam overrun prevention device in the cycle sewing machine of the present invention having the above-described structure, the driving side member and the driven side member of the one-way clutch are formed when the rotational driving force is transmitted from the driving source. The generated tooth portions are meshed with each other by the spring member, and the rotation output of the worm gear, which is a speed reducer, can be transmitted to the feed cam. When the feed cam tries to overrun after the rotation driving force from the driving source is stopped, the rotation driving force reversely transmitted to the driven side member of the one-way clutch attempts to rotate the driving side member. The driving-side member of the one-way clutch, which is locked to the worm wheel in the fixed state, operates in a direction away from the driven-side member, and sliding resistance is generated at the meshing portion between the driving-side member and the driven-side member. As a result, the reversely transmitted rotational driving force generated when the feed cam tries to overrun can be stopped.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Note that the same or corresponding configurations as those of the conventional one described above are denoted by the same reference numerals in the drawings, and description thereof will be omitted.

As shown in FIGS. 1 to 5, in this embodiment, the rotational driving force of an electric motor or the like, which is a drive source (not shown), is reduced by a speed reducer composed of a worm 4 and a worm wheel 5, and a horizontal axis is used. It is formed so as to be transmitted to a feed cam via a one-way clutch 28 provided in a portion 6a, and is biased by a groove 25 provided in the conventional feed cam 15 and a brake spring 26 abutting against the groove 25. And the brake band 27 has been deleted.

The one-way clutch 28 includes the driving member 2
9 and the driven member 30 are divided into two parts, and are formed integrally by axially meshing the tooth portions 32a and 32b formed on the surfaces facing each other by a compression spring 35 which is a spring member.

The one-way clutch 28 will be further described. One driven member 30 is fixed to the horizontal shaft 6a with a set screw 7, and the other driven member 29 is fixed.
Is the distance L between the driven member 30 and the worm wheel 5.
Horizontal shaft 6 that can be freely moved in the axial direction and can be rotated
It is loosely fitted in a. On the end surface of the driving side member 29 facing the boss portion 33 provided at one end of the worm wheel 5, a suitable number of engaging projections 37 are provided at two positions facing the diametrical position in this embodiment. There is. Then, each engaging convex portion 37 is engaged with each engaging concave portion 36 provided in the boss portion 33 of the worm wheel 5 so as to be slidable only in the axial direction. Thereby, the driving force from the worm wheel 5 is formed to be transmitted to the driving side member 29.

The compression spring 35 is composed of the worm wheel 5
Is mounted in an annular mounting space 34 formed between the inner peripheral surface of the boss portion 33 and the outer peripheral surface of the horizontal shaft 6a, and the end of the compression spring 35 is attached to the worm wheel 5 of the drive side member 29.
Is elastically contacted with an end surface opposed to and the other end is elastically contacted with a C ring 42 arranged near the lower surface 41 of the mounting space 34. The compression spring 35 constantly applies an urging force to the driving-side member 29 to move it from the worm wheel 5 in the direction of the arrow G in FIG.

The engaging concave portion 36 and the engaging convex portion 37 need only be engageable with each other, and are not particularly limited to this embodiment. And the mounting space 3
4 and the engaging recess 36 may be formed on the end surface of the worm wheel 5 instead of on the inner peripheral surface or the end surface of the boss portion 33 provided at one end of the worm wheel 5. It is not limited.

The shapes of the teeth 32a and 32b formed at the opposing portions of the driving side member 29 and the driven side member 30 are such that the driving force of the driving side member 29 is transmitted to the driven side member 30 in one direction. As long as it is formed,
The present embodiment is not limited.

Further, as shown in FIGS. 1, 3 and 4, the outer peripheral surface 40 of the feed cam 39 applied to this embodiment has a tooth portion 16 meshed with the drive gear 17 unlike the conventional example.
Only formed. Others are formed similarly to the above-mentioned conventional example.

A bevel spring or the like may be applied instead of the compression spring 35 described above. In this case, it is not necessary to form the mounting space 34 provided on the inner peripheral surface of the boss portion 33. Further, the worm wheel 5 and the driving side member 2
The coupling method with 9 is not limited to the engagement by the engagement concave portion 36 and the engagement convex portion 37, but may be a meshing clutch in which a claw is formed on the adjoining opposing surfaces of the both, and is not limited to this embodiment. is not.

Next, the operation of this embodiment having the above-mentioned structure will be described.

When the driving force is transmitted by driving the sewing machine, the rotational driving force of the electric motor or the like, which is a drive source (not shown), is transmitted to the drive pulley 3 of the input shaft 2 by the V belt or the timing belt. The drive pulley 3 is shown in FIG.
By rotating the input shaft 2 in the same direction by rotating it in the direction of the middle arrow A, the worm 4, which is the input side of the speed reducer fixed to the appropriate position of the input shaft 2, is rotated in the rotation direction A. The rotational force of the worm 4 on the input side of the speed reducer is transmitted to the worm wheel 5 on the output side of the speed reducer to rotate the worm wheel 5 in the direction of arrow B in FIG. Further, the driving force transmitted to the worm wheel 5 is transmitted to the driving side member 29 of the one-way clutch 28 by the engagement between the engagement concave portion 36 and the engagement convex portion 37, as shown in FIG. Then, the tooth portions 32a of the driving side member 29 and the driven side member 30,
32b is always meshed with the compression spring 35, and only the driving force transmitted to the driving side member 29 in the direction of arrow B in FIG. 2 is transmitted to the driven side member 30. Subsequent driving force transmission operates in the same manner as the above-mentioned conventional example.

As shown in FIGS. 3 and 4, when the sewing machine is stopped by a stop instruction, the cylindrical roller 23 stops at the position where it abuts the inclined surface 21 of the flat cam 19. At this time, the cylindrical roller 23 presses the inclined surface 21 of the flat cam 19, so that the force causes the feed cam 39 to overrun in the direction shown by the arrow F in FIG. 1 as in the conventional example.
This overrunning force is reversely transmitted from the feed cam 39 to the drive source side, and the driven side member 30 of the one-way clutch 28.
Is transmitted to Then, in the one-way clutch 28,
The reversely transmitted rotational force in the direction indicated by arrow G in FIG. 3 acts on the driven member 30. At this time, the driving side member 29 engaged with the worm wheel 5 is in a fixed state.

The rotational force for rotating the driven member 30 in the direction indicated by the arrow H in FIG. 3 also attempts to rotate the driving member 29 in the same direction, but the driving member 29 compresses the compression spring. 3 is contracted while trying to separate from the driven side member 30 in the axial direction shown by the arrow I in FIG.
A load torque due to sliding resistance is generated between the sloped surface 43a of the serrated tooth 32a of No. 9 and the sloped surface 43b of the serrated tooth 32b of the driven member 30. This load torque can stop the rotational force reversely transmitted from the feed cam 39.

Therefore, even if the cylindrical roller 23 arranged on the needle swing control arm 22 stops at the inclined surface 21 of the flat cam 19 formed on the feed cam 39, the feed cam 39 is held at the stop position. You can Since the load torque prevents the feed cam 39 from overrunning, a drive motor having a smaller capacity than the conventional one can be applied to reliably prevent the feed cam 39 from overrunning. It is an overrun prevention device for the feed cam in a high cycle sewing machine.

The present invention is not limited to the above embodiment, but can be modified as necessary.

[0034]

As described above, according to the feed cam overrun prevention device in the cycle sewing machine of the present invention, the one-way clutch is divided into the driving side member and the driven side member which are movable in the axial direction. , A tooth portion that transmits a driving force in one direction is provided on the opposing surfaces of the two, and the driving side member is brought into contact with the driven side member by the urging force, and the both tooth portions are meshed to form a feed cam. Even if the cylindrical roller placed on the needle swing control arm stops due to the inclined part of the flat cam, the feed cam can be held at that stop position, and the overrun of the feed cam is ensured with a simple structure. In addition to being able to prevent it, it is possible to reduce the capacity of the drive motor, further improve durability and maintain high reliability over a long period of time, and it is possible to achieve an extremely economical effect.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of essential parts showing an entire embodiment of a feed cam overrun prevention device in a cycle sewing machine of the present invention.

FIG. 2 is a front view of a main part showing a one-way clutch part.

FIG. 3 is a diagram illustrating a state where a feed cam overrun occurs.

FIG. 4 is a development view illustrating a plane cam of a feed cam.

FIG. 5 is an explanatory view of essential parts for explaining the operation of the feed cam overrun prevention device in the cycle sewing machine of the present invention.

FIG. 6 is an exploded perspective view of essential parts showing the entire feed cam overrun prevention device in a conventional cycle sewing machine.

FIG. 7 is a front view of the main part of FIG.

FIG. 8 is a front view of a main part for explaining a stopped state of a feed cam.

[Explanation of symbols]

 2 Input Shaft 4 Worm 5 Worm Wheel 6a, 6b Horizontal Shaft 8 Clutch Collar 9 Engagement Hole 10 One-way Clutch Spring 12a, 12b Spur Gear 14 Drive Shaft 19 Planar Cam 21 Sloping Surface 23 Cylindrical Roller 28 One-way Clutch 29 Driving Side Member 30 driven side member 32a, 32b tooth part 35 compression spring 36 engagement concave part 37 engagement convex part 39 feed cam 43 slope

Claims (1)

[Scope of utility model registration request] 1. A speed reducer composed of a worm and a worm wheel that reduces the rotational drive force of a drive source rotationally driven in one direction, and a rotational drive force of a worm wheel that is an output side of the speed reducer is fed to a driven side. A one-way clutch that transmits to a cam, the one-way clutch is configured by a driving side member and a driven side member, and one end of the driving side member is urged in a direction separating from the worm wheel. The worm wheel is engaged with a worm wheel via a spring member that is freely moved, and the other end and one end of the driven side member are engaged with each other by a tooth portion formed in a direction for transmitting the rotation output from the speed reducer to the feed cam. A feed cam overrun prevention device in a cycle sewing machine, wherein the driven member is fixed to an output shaft.