JPS5845669Y2 - Cycle sewing machine stitch number conversion device - Google Patents

Description

[Detailed description of the invention] This invention relates to a count conversion device for a cycle sewing machine.

Conventionally, in cycle sewing machines that complete one-edge sewing operation in a cycle corresponding to the required count, for example, in industrial lockstitch button sewing machines, the two-hole button B1 is sewn with nine stitches as shown in Figure 1a. As shown in Figure 1, the four-hole button B2 may be sewn onto the workpiece fabric using 18 stitches, which is twice the count for the two-hole button B1. - It was necessary to change the number of stitches in a sewing cycle as necessary.

This idea was made in consideration of such circumstances, and cycle sewing machines, such as those with industrial lockstitch buttons, require manual switching when sewing two-hole buttons or four-hole buttons. It is an object of the present invention to provide a novel count conversion device for a cycle sewing machine, which allows the count in a sewing cycle to be easily and automatically changed by simply switching a lever.

Hereinafter, this invention will be explained in detail based on an embodiment of an industrial lockstitch button sewing machine. In the drawing, 1 is a frame of the sewing machine, which includes a bed part 1a having a workpiece support surface and It consists of an arm portion 1b above it.

Reference numeral 2 denotes a needle bar mounted on the head of the arm portion 1b so as to be movable up and down, and a needle 3 is attached to the lower end of the needle bar. do not)
It is designed to form a lockstitch seam in cooperation with the sewing machine.

Reference numeral 4 denotes a feed stand supported on the upper surface of the bed portion 1a of the frame 1 so as to be movable in a direction (horizontal direction) across the vertical movement path of the needle 3, and the front part thereof (the left part in Fig. 2.3). A feed plate 5 is attached to the.

Reference numeral 6 denotes a presser arm rotatably supported by the feed base 4 by a support shaft 7, and an operating pin 6a is protruded from the upper surface of the intermediate portion thereof.

Reference numeral 8 denotes a button gripper which also serves as a pair of presser feet, which is rotatably supported by the front end of the presser arm 6 via a support plate 9, and has two holes or four holes between the distal ends of the gripper 8. The buttons Bl and B2 with holes are held in the state shown in FIGS. 1 and 2, and the work cloth is held between the feed plate 5 and the feed plate 5.

10 is a support fixed to the lower surface of the arm portion 1b of the frame 1; 11 is a presser spring interposed between the support 10 and the presser arm 6; The button holder 8 is urged counterclockwise to press the button holder 8 toward the work cloth on the feed plate 5.

Reference numeral 12 denotes a rotary lever rotatably supported by the support body 10, and the front end of the rotary lever 12 can engage the operating pin on the presser arm 6 with the lever 6a.

Reference numeral 13 denotes a presser foot lifting member provided at the lower part of the arm portion 1b of the frame 1 so as to be movable up and down, and the lower end thereof is connected to the rear end of the rotary lever 12.

In this embodiment, at the end of one sewing cycle of the sewing machine, the presser foot lifting member 13 is lowered via a power operating mechanism (not shown), and the presser foot arm 6 is lowered via the rotary lever 12 as shown in FIG. direction, the pressing pressure of the button holder 8 on the workpiece cloth is released, and in this state, the workpiece cloth is inserted onto the feed plate 5 and the button is inserted between the button holders 8. When the sewing machine is started by depressing a starting pedal (not shown), the presser foot lifting member 13 is raised and the presser foot arm 6 is raised by the action of the presser spring 11.
is rotated counterclockwise to apply pressing pressure to the work cloth.

Next, the starting/stopping mechanism of the sewing machine will be explained with reference to FIGS. 4 to 8.

Reference numeral 14 denotes a main shaft of the sewing machine which is rotatably supported within the arm portion 1b of the frame 1, and is configured to impart vertical movement to the needle 3 and rotation to the shuttle via an appropriate linkage device. It has become.

15 and 16 are a pair of clutch plates fixed at a predetermined interval to the tip of the main shaft 14 of the sewing machine, and 17 are both clutch plates 15.
．． 16 is a sliding tube that is slidably fitted onto the main shaft 14 via a bearing metal, and one end thereof has a plurality of protrusions 17a that pass through holes in one of the clutch plates 16. The main shaft 142, both clutch plates 15, 16, and the sliding tube 17 rotate integrally.

A pair of pulleys 18 and 19 are rotatably supported by the sliding tube 17 via bearings, and each clutch plate 15
．． Clutch bodies 18a and 19 are provided in the parts corresponding to 16.
It is equipped with a.

One pulley 18 is connected to a low-speed drive source via a belt 20, and the other pulley 19 is connected to a high-speed drive source via a belt 21.

A compression spring 22 is interposed between one of the clutch plates 15 and the sliding tube 17, and urges the sliding tube 17 to move in the direction of the arrow in FIG.

Reference numeral 23 denotes a support member attached to the tip of the protrusion 17a of the sliding tube 17, and a steel ball 24 is rotatably accommodated in a recess on the outer surface of the support member.

Reference numeral 25 denotes an operating member rotatably supported within the frame 1 of the sewing machine around a support shaft 26 parallel to the axis of the main shaft 14, and has a continuous ring at its upper end that can engage with the steel ball 24. A cam plate 27 having curved cam surfaces 27 a , 27 b , 27 C is attached.

Also, it is connected to the starting pedal via this operating member 28 and the power operating mechanism for lifting the presser foot, and the connecting rod 29
is operatively connected to a cam contactor of a cam mechanism to be described below.

Note that 30 is a tension spring for biasing the operating member 25 to rotate in the clockwise direction in FIG.

Therefore, by depressing the starting pedal, the operating rod 28
When the operating member 25 is rotated in the counterclockwise direction in FIG. 6 via the 22 in the opposite direction of the arrow in FIG. 7, the clutch body 18a of the pulley 18 engages one clutch plate 15, and low-speed rotation is transmitted to the main shaft 14.

Thereafter, when the cam surface 27C of the cam plate 27 is moved to a position facing the steel ball 24 based on the action of the cam mechanism,
The sliding tube 17 is slid in the direction of the arrow in FIG. 7 by the action of the compression spring 22, and the clutch body 19a of the pulley 19 engages with the other clutch plate 16, so that high-speed rotation is transmitted to the main shaft 14.

Furthermore, since the operating member 25 is held at the rotational position by the cam mechanism via the connecting rod 29 until one sewing cycle is completed, even if the starting pedal is subsequently released, the sewing machine will not operate. Operation will not be stopped.

Then, at the end of the - cycle sewing operation, the operation member 25 is rotated back by the action of the tension spring 30 based on the action of the cam mechanism, and the main shaft 14 changes from high speed rotation to low speed rotation and then stops.

Reference numeral 31 denotes a brake member rotatably supported within the frame 1 of the sewing machine by a support shaft 32 at one end, and as shown in FIG. A brake shoe 31a is attached.

33 is a cam hole formed in the brake member 31,
Cam portions 33 a and 33 b are provided on the inner circumferential surface thereof, with which retaining pins 34 protruding from the operating member 25 engage.

Reference numeral 35 denotes a tension spring provided between the brake member 31 and the sewing machine frame 1, which biases the brake member 31 to rotate in the counterclockwise direction in FIG. It is adapted to be brought into pressure contact with the outer peripheral surface of the plate 15.

Therefore, when the operating member 25 begins to rotate in the direction of the arrow in FIG. When the brake member 31 is slightly rotated and its brake shoe 313 is separated from the outer peripheral surface of the clutch plate 15 , and the operating member 25 is then further rotated, the retaining pin 34 is moved to the other cam portion of the cam hole 33 . 33b, a lost motion occurs between the operating member 25 and the brake member 31, and the brake member 31 is held at the rotational position regardless of the rotation of the operating member 26.

Then, as described above, when the sewing operation is finished, the operating member 25
When the brake member 31 is returned to rotation by the action of the tension spring 30, the brake member 31 is returned to rotation by the action of the tension spring 35.
The brake shoe 31a comes into pressure contact with the outer peripheral surface of the clutch plate 15, and the main shaft 14 is stopped by braking.

36 is a fixed position stopping cam fixed to the main shaft 14 as shown in FIGS. 5 and 6, and a part thereof has a notch 36.
It has a.

37 is a stopper member inserted into the hole 38 on the operating member 25, and is capable of engaging with a protrusion 37a that can engage with the notch 36a of the cam 36 and a part of the operating member 25. A shoulder portion 37b is formed.

A rod 39 is inserted into the stopper member 37 and the operating member 25, and has a head 39a that engages with the stopper member 37 at its upper end.

A compression spring 40 is interposed between the stopper member 37 and the operating member 25, and urges the stopper member 37 upward.

Therefore, when the operating member 25 is rotated in the direction of the arrow in FIG. 6 as the starting pedal is depressed as described above, the protrusion 37a of the stopper member 37 moves out of the rotational trajectory of the cam 36. , rotation of the main shaft 14 is allowed.

Further, when the operating member 25 is rotated back in the direction opposite to the arrow at the end of the sewing operation, both pulleys 18 and 19 are moved toward the clutch plate 15.
．． 16 and while the main shaft 14 is rotating at a low speed, the protrusion 37a of the stopper member 37 engages with the outer peripheral surface of the cam 36, and then the protrusion 37a engages with the outer peripheral surface of the cam 36.
The main shaft 14 is stopped at a predetermined position.

Next, the fourth, ninth to first cam mechanisms for operating the start/stop mechanism of the sewing machine in relation to the rotation of the sewing machine main shaft 14 and in cycles corresponding to a required count will be described.
This will be explained based on FIG.

Reference numeral 41 denotes a camshaft rotatably supported in the frame 1 of the sewing machine around a vertical axis, and as the sewing machine main shaft 14 rotates, the worm 42 and the worm wheel 43 rotate.
It is designed to be rotated at a reduced speed in the counterclockwise direction in FIGS. 4 and 9.

Reference numeral 44 denotes a first cam fixed to the central part of the camshaft 41 by a screw 45, and on its outer periphery are a stop cam part 44a, a low speed cam part 44b, and a high speed cam part 44C.
Four sets of cam parts having the same shape, including one set of low-speed cam part 44d, are formed, and as the sewing machine main shaft 14 rotates, sewing operation is performed in a cycle corresponding to the number of nine stitches. , this first cam 44 is rotated by an angular amount (90°) corresponding to one set of cam portions.

A first cam contactor 46 is rotatably supported on the sewing machine frame 1 by a rotary shaft 47 outside the first cam 44, and each cam of the first cam 44 is attached to the tip of the first cam contactor 46. Engagement rollers 46a that can engage with portions 44a-d are rotatably mounted.

Reference numeral 48 denotes a connecting lever fixed to the upper end of the rotating shaft 47, and the operating member 25 of the starting/stopping mechanism is attached to the end of the connecting lever.
A connecting rod 29 extending from the two is connected to each other.

Therefore, the first cam contact 46 is normally urged to rotate in the counterclockwise direction in FIG. 9 by the action of the tension spring 30 applied to the operating member 25, and the engaging roller 46a It is arranged to engage with the cam portion of the cam 44.

As shown in FIG. 9, when the sewing machine is stopped, the engaging roller 46a of the cam contactor 46 is located within the stopping cam portion 44a of the first cam 44, and the starting pedal is pressed as described above. Operation member 2 of the start/stop mechanism upon stepping operation
5 is rotated counterclockwise from the state shown in FIG. 6 to start the sewing machine, the cam contactor 46 is rotated clockwise from the state shown in FIG. 9 via the connecting rod 29, the connecting lever 48, etc. When the engaging roller 46a is moved, the engaging roller 46a separates from the stopping cam portion 44a.

Further, after the sewing machine is started, as the first cam 44 that interlocks with the sewing machine main shaft 14 rotates, the first and second stitches of the needle 3 are sewn as shown at positions 1 to 9 in FIG. During operation, the engaging roller 46a of the cam contactor 46 engages with the low speed cam portion 44b of the negative cam 44, and the operation member 25 of the start/stop mechanism is held at the low speed position, and the third During the sewing operation of the 5th stitch to 5th stitch, the engaging roller 46a engages with the high speed cam part C to switch and hold the operating member 25 at the high speed position, and furthermore, during the 6th to 8th stitch sewing operation, the engaging roller 46a engages with the high speed cam portion C. 46a engages with the low-speed cam portion 44d, and the operating member 25 is switched to and held at the low-speed position, and with the sewing operation of the 9th stitch, the engaging roller 46a engages with the stop cam portion 44a, and the operation member 25 is switched to the low-speed position. The member 25 is adapted to be returned to the rest position shown in FIG.

49 indicates the camshaft 4 near the lower end of the camshaft 41.
As the camshaft 41, which is a rotary shaft rotatably supported within the frame 1 of the sewing machine and extends parallel to the sewing machine main shaft 14, rotates, the gear 5 rotates.
0.51, and is rotated clockwise in FIGS. 4 and 9 at the same speed as the camshaft 41.

A second cam 52 is fixed to the rotating shaft 49, and has a high cam portion 53a and a low cam portion 53 on its outer periphery.
Two sets of cam parts 5 for controlling the number of stitches having the same shape, with b as one set.
3 is formed on the top surface of the feed table 4 of the workpiece feed mechanism shown in FIGS. 2 and 3 in the vertical direction (X-X in FIGS.
vertical feeding cam portion 54 for imparting feeding motion in the direction)
is formed, and a lateral feed cam portion (not shown) is formed on the lower surface for imparting a feed motion in the lateral direction (Y-Y direction in FIGS. 1 and 3) to the feed table 4, etc. has been done.

A second cam contactor 55 is rotatably supported on the frame 1 of the sewing machine by a rotary shaft 56 outside the second cam 52, and the needle of the second cam 52 is attached to the tip of the second cam contactor. An engaging roller 55a that can engage with the number control cam portion 53 is rotatably attached.

57 is a tension spring provided between the second cam contactor 55 and the frame 1, which biases the cam contactor 55 to rotate in the clockwise direction in FIG. a is held in a state of engagement with the cam portion 53 for controlling the number of stitches.

As shown in the O position in FIG. 15, when the sewing machine is stopped, the engaging roller 55a of the second cam contactor 55 is engaged with the high cam portion 53a of the cam portion 53 for controlling the number of stitches. , and after starting the sewing machine, the sewing machine main shaft 1
As the second cam 52 rotates in conjunction with the 15th cam 52, the 15th
As shown at positions 1 to 18 in the figure, up to the sewing operation of the first and second stitches of the needle 3, the engaging roller 55a of the cam contactor 55
is maintained in a state engaged with the high cam part 53a of the cam part 53 for controlling the number of stitches, and during the sewing operation of the 3rd to 13th stitches,
The engaging roller 55a engages with the low cam portion 53b, and the first
During the sewing operation of the 4th to 18th stitches, the engaging roller 55a again engages with the high cam portion 53a.

Reference numeral 58 denotes a rotating lever fixed to the upper end of the rotating shaft 56, and a two-pronged engagement portion 58a is formed at the tip thereof.

Reference numeral 59 denotes a holder which is loosely fitted and supported on the camshaft 41 at the lower part of the first cam 44, and the lower surface of one side thereof engages with the bifurcated engaging portion 58a of the rotary lever 58. A retaining pin 59 a is provided protrudingly on the other side outer surface and engages with the engaging roller 46 a of the first cam contactor 46 .
6 a separated from each cam portion 44 a to 44 d of the first cam 44, and the engaging roller 46
A holding portion 59b is formed to hold the shaving portion 59a at approximately the same position (strictly speaking, at a slightly higher position) than the position moved by the high-speed cam portion 44C during first cam shaving.

Then, as shown in FIG. 9, the second cam contactor 55
When the engaging roller 55 a is engaged with the high cam portion 53 a of the stitch number control cam portion 53 of the second cam 52 (the 15th
During the sewing operations of the 6th to 8th stitches and the 14th to 18th stitches in the figures), the holding body 59 is placed in an inactive position where it does not engage with the engaging roller 46a of the first cam contactor 46,
Further, as the second cam 52 rotates, the engaging roller 55a of the second cam contactor 55 engages with the lower cam portion 53b of the cam portion 53 for controlling the number of stitches, as shown in FIG. At the time (during the sewing operation of the 3rd to 13th stitches in FIG. 15), the holding body 59
6a, and is adapted to be pivoted into an operating position in which it engages with 6a.

Therefore, when the needle 3 is sewing the first and second stitches when the sewing machine is started, the engaging roller 46 of the first cam contactor 46
a engages with the low-speed cam portion gap of the first cam 44,
The main shaft 14 of the sewing machine is rotated at a low speed by the action of the cam portion 44b, and during the sewing operation of the third to thirteenth stitches, the engaging roller 46a is moved to the first position by the holding portion 59a of the holding body 59.
The low-speed cam portion 44d is maintained in a high-speed control state separated from the cam portions 44a to 44d of the first cam 44, and corresponds to the sixth to eighth stitches of the first cam 44, and the stop cam corresponds to the ninth stitch. Regardless of the presence of part 44H, sewing machine main shaft 1
4 is rotated at high speed, and during the 14th to 18th stitch sewing operation, the engaging roller 46a of the first cam contactor 46 engages with the cam portion of the first cam 44 again as shown in FIG. hand,
The main shaft 14 of the sewing machine is stopped after rotating at a low speed by the action of the low speed cam portion 44 d and the stopping cam portion 44 a.

Next, without receiving the action of the stitch number control cam part 53 of the second cam 52, the cam part 44a of the first cam shaft is moved.
44d, a configuration for switching to perform the sewing operation with nine stitches as a -cycle will be described.

60 is the bottle 60 at the proximal end as shown in Fig. 9.10.12.
A manual switching lever made of an elastic plate fixed to the holder 59 with a screw 61 at a portion a, the free end of which is a through hole 62 formed in a part of the sewing machine frame 1.
An operating portion 60b for rotating the holding body 59 is bent at the end thereof.

Reference numeral 63 denotes a locking plate fixed to the outer surface of the sewing machine frame 1 with a screw 64 on one side of the through hole 62, as shown in FIGS. In order to arrange at two different switching positions, two switching setting parts 63b, 6 are inserted between the locking protrusion 63a.
3C is provided.

Reference numerals 65 and 66 are indicators attached to the surface of the locking plate 63 corresponding to the switching setting portions 63b and 63C, and indicate the counting switching positions of 18 stitches and 9 stitches.

Therefore, as shown by the solid line in FIG.
When the switch is set to the b side, rotation of the holding body 59 is allowed, so when the sewing machine is started, the holding body 59 is affected by the action of the stitch number control cam part 53 of the second cam 52. is rotated between the inactive position of FIG. 9 and the active position of FIG. 12, and the first and second cams 44.
Based on the cooperative operation of 52, a sewing operation is performed in which the number of stitches is 18 in -cycles.

In addition, as shown by the chain line in FIG. 11, when the manual switching lever 60 is switched to the 9-stitch switching setting section 63C side based on the indicator 66 and the locking protrusion 63a locks it in the middle part. 9, the holding body 59 is rotated clockwise from the state shown in FIG.
5 is rotated counterclockwise, and the engaging roller 55a is disengaged from the stitch number control cam portion 53 of the second cam 52, as shown in FIG.

Therefore, when the sewing machine is started in this switching state,
With the engaging rollers 46 a of the first cam contactor 46 always engaged with the cam portions 44 a to 44 d of the first cam 44, the main shaft 14 of the sewing machine is rotated by the action of the cam portions 44 a to 44 d. The rotation is controlled, and a sewing operation is performed with a cycle of nine stitches.

Next, a configuration for moving the feed table 4 and the like of the workpiece feed mechanism based on the vertical feed cam portion 54 and the horizontal feed cam portion of the second cam 52 will be described.

67 and 68 are swingably supported within the sewing machine frame 1 so as to engage with the vertical feed cam part 54 and the horizontal feed cam part (not shown) of the second cam 52, as shown in FIG. With the rotation of the second cam 52, which is the second and second cam follower that is rotated in conjunction with the sewing machine main shaft 14,
It is designed to swing based on the cam portion.

Reference numerals 69.70 and 69.70 respectively correspond to the respective cam followers 67.68, and are swingably supported within the sewing machine frame 1.
and a second swinging lever, the cam follower 67.68
As the workpieces swing, the workpieces shown in FIGS. The feed table 4 and the like of the feed mechanism are moved in the X-X direction and the Y-Y direction.

In this embodiment, when the manual switching lever 60 is switched to a state in which -cycle sewing operation is performed with a count of 18 stitches, the swing ratio changing section 71.7
Based on the adjustment setting of 2, half a rotation of the second cam 52 causes the first
In order to sew the four-hole button B2 on the workpiece cloth as shown in the figure, a feeding motion is applied to the feed table 4, etc., and a -cycle sewing operation is performed with a count of 9 stitches. When the state is changed to the state in which the swing ratio changing section 71.
Based on the adjustment setting of 72, a feed movement is applied to the feed table 4, etc., so that the second cam 52 turns a quarter turn to sew the two-hole button B1 on the workpiece cloth as shown in FIG. 1a. It is now possible to do so.

As is clear from the above description, in the button-equipped sewing machine of this embodiment, the manual switching lever 60 protruding outward from the sewing machine frame 1 can be used to move the holder 59 into the operation permissible state shown in FIG. By simply switching to the operational restraint state shown in FIG. first cam 4
4, the rotation of the main shaft 14 of the sewing machine is automatically controlled by the action of the sewing machine 4, making it easy to sew a four-hole button B2 or a two-hole button B1 as shown in FIG. can be done.

Note that the invention is not limited to the above embodiments,
For example, when sewing a two-hole button B1 with a button according to the above embodiment, the manual switching lever 60 is sometimes moved to the rotational position shown in FIG. The second cam 52 can be restrained in a position where it does not act on the matching roller 46a, and the second cam 52 is activated when the sewing machine is started.
Due to the rotation of the engaging roller 55 of the second cam contactor 55
The cam part 53 a of the stitch number control cam part 53 may be configured to engage with the high cam part 53 a but not be engaged with the low cam part 53 b and be held in a state separated from the intermediate part. By changing the cam shape of the second cam 44, 52, the number of stitches in the sewing cycle can be set to an arbitrary value, etc.
The structure of each part can be changed as appropriate without departing from the spirit of this invention, and this invention can also be embodied in cycle sewing machines other than the button-equipped sewing machine of the above embodiment.

As detailed above, this invention enables a cycle sewing machine, for example, an industrial lockstitch button sewing machine, to sew a two-hole button or a four-hole button by simply switching the manual switching lever. The counting in a cycle can be easily and automatically changed, and there is no need for the complicated work of replacing control cams, etc., and the sewing operation can be immediately started, which is an excellent effect.

[Brief explanation of the drawing]

Figure 1 a, l) is a front view showing the state of sewing two-hole buttons and four-hole buttons, Figure 2 is a partial side view of the sewing machine with buttons embodying this invention, and Figure 3 is a partial side view of the sewing machine. is 3- in Figure 2.
3 is a cross-sectional view taken along line 3, FIG. 4 is a perspective view of a main part showing a cam mechanism for controlling starting/stopping of the sewing machine and feeding of the workpiece, FIG. 5 is a partial side view showing the starting/stopping mechanism of the sewing machine, and FIG. 6 is a rear view, FIG. 7 is a partial sectional view taken along line 7-7 in FIG. 6, FIG. 8 is a partial sectional view taken along line 8-8 in FIG. 6, and FIG. 9 is an enlarged view of the cam mechanism. 10 is a partially enlarged sectional view taken along line 10-10 in FIG. 9, FIG. 11 is a partially enlarged sectional view taken along line 11-11 in FIG. 9, and FIGS. FIG. 9 is a partial sectional view showing different operating states; FIG. 14 is an explanatory view showing the engagement position of the first cam contactor with respect to the first cam in correspondence with the count in one sewing cycle; FIG. 15 FIG. 3 is an explanatory diagram showing the engagement position of the second cam contactor with respect to the cam portion for controlling the number of stitches of the second cam in correspondence with the count in one sewing cycle.

Claims (1)

[Claims for Utility Model Registration] A sewing machine main shaft rotatably supported on the frame of a sewing machine and for imparting vertical movement to the needle, and a sewing machine main shaft provided between the sewing machine main shaft and a drive source to start the sewing machine main shaft, a start/stop means for stopping the sewing machine; a workpiece feeding mechanism for holding a workpiece on the bed of the frame and moving the workpiece across the vertical movement path of the needle; and a main shaft of the sewing machine. a first cam that is rotated in conjunction to operate the activation/stopping means with a cycle corresponding to a required count; one end of the cam can be engaged with the first cam, and the other end of the cam can engage the activation/stopping means; a cam contactor operatively connected to the sewing machine main shaft, the cam contactor being rotated in conjunction with the sewing machine main shaft to provide a feed movement to the workpiece feeding mechanism in a count of an integral multiple of the number of stitches corresponding to one cycle of the first cam; and a second cam for imparting the cam contactor to the first cam, regardless of the rotation of the first cam, until immediately before the end of one sewing cycle by the second cam. between an active position for holding the cam contactor disengaged from the first cam and an inactive position for releasing the cam contactor from the holding position and engaging the first cam at the end of the sewing cycle. a holder to be operated; a manual switching lever having a proximal end fixed to the holder and a free end extending outside the frame; and a manual switching lever for manually operating the holder; provided on said frame for operative locking of said lever in two different switching positions, allowing said retainer in one position to be actuated by a second cam and in the other position; A count conversion device for a cycle sewing machine, comprising: a locking means for restraining the holding body in the inactive position.