JPS5847195B2 - Safety device for cycle sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention enables the sewing machine to be driven by transmitting the rotation of the drive motor to the main shaft by starting the sewing machine by, for example, depressing a foot pedal by an operator, and starting the sewing machine after forming a predetermined number of stitches. Regarding cycle stitch sewing machines that automatically stop the sewing machine by cutting off the transmission, it is particularly important to use grooves that rotate around a fixed axis when the sewing machine is driven, and whose starting and ending ends are located at different distances from the center of rotation within the plane of rotation. A guide cam is formed with a guide section like a rail, and the sewing machine is fitted into the guide section of the guide cam between the time when the sewing machine is driven and stopped, and is guided from its starting end to its terminal end, and swings around a fixed axis. The sewing machine is configured such that the rocking body and the workpiece are held in the sewing area of the sewing machine, and the swinging of the rocking body causes the first stitch and the last stitch to drop on the workpiece at different positions in accordance with the guide section. The oscillating body is provided with a fabric holding means that swings on the bed surface, and if a worker accidentally sews with the foot pedal depressed, the oscillating body moves the guide part of the guide cam. The present invention is characterized by the provision of a guide mechanism that stops the rotation of the drive motor until it reaches the end.

Conventionally, in this kind of cycle stitch sewing machine, when the starting end and the ending end of the guide portion of the guide cam are located at a position I which is the same distance from the rotation center of the guide cam, that is, when the start end and the end end of the guide portion of the guide cam are located at a position I, the distance between If the needle drops in the same position as the first stitch and the last stitch, the sewing machine may If the sewing machine simply repeats the same cycle stitch without stopping, or if the starting and ending ends of the guide section are at different distances from the center of rotation of the guide cam, in other words, a cycle stitch is formed on the workpiece. If the foot pedal is kept depressed when the first and last stitches of the sewing machine drop into different positions, the oscillating body may collide with the end wall at the end of the guide section, damaging the sewing machine or causing injury to the operator. Accidents that result in unexpected serious injuries occur.

In order to prevent such accidents from occurring, this invention stops the rotation of the drive motor before the rocking body reaches the end of the guide section if the worker mistakenly continues to work with the foot pedal depressed. It is an object of the present invention to provide the above-mentioned cycle stitch sewing machine which is free from the risk of the occurrence of the above-mentioned accident. A cycle sewing machine 2, such as a bar tack sewing machine, which is started by pressing a foot pedal or the like and stops after forming a predetermined number of stitches, is installed, and on the left side there is a machine for feeding fabric into the sewing machine 2. Install the cloth feeding mechanism 3.

First of all, as shown in Figs. 3 and 4, this sewing machine 2 is idle-rotating on a main shaft (not shown) protruding from the rear end surface, which is constantly linked to a drive motor (not shown) via a belt 4. The rotation of the drive boob IJ-5 is controlled by rotating a fixed shaft 6 on the rear end surface of the sewing machine (a cutoff lever 7, which is rotatably installed) counterclockwise from the solid line position in Fig. 4 by an operator's starting operation described later. A cam 8 is installed on the side of the sewing machine frame (right side in Fig. 1) to rotate at a reduced speed counterclockwise in conjunction with the main shaft. The camshaft 8 has a base plate 9 formed on the disk and slidably installed on the bed of the sewing machine on the front side of the base plate 9, for controlling the left and right movement of the base plate 9 so that its starting position and stop position are different. A guide groove 10 is formed so as to gradually approach the axis of the camshaft 8 from its starting end 10a to its terminal end 10b, and the above-mentioned guide groove 10 is formed on the outer peripheral surface of the feed cam 11, which communicates these ends with a return groove 10c. Move the cutoff lever 7 to the stop position (solid line position in Figure 4)
A control cam 12 on a disk is fixed, and the control cam 12 is formed on a disc with a concave portion 12a formed therein and the outer periphery of which locks the cutoff lever 7 in the counterclockwise rotation state, and One end of the surface is provided with a roller 13a that engages with the outer peripheral edge of the control cam 12, and the other end is provided with an engaging portion 13b that engages with a contact point of a second switch, which will be described later, and an arcuate hole 1 that is elongated in the vertical direction.
A locking piece 14 with a bent tip is provided at one end of the L-shaped control lever 13 located between the control lever 13 and the machine frame surface, and a locking piece 14 is provided at the lower end of the other end. The middle part of the transmission lever 15, which has a stepped portion 15a formed on its edge, is rotatably supported by a stepped screw 16, and is rotatably supported by the stepped screw 16. (No) A counterclockwise acting force is applied to the control lever 13 so that the roller 13a is always pressed against the outer peripheral surface of the control cam 12.

Further, as shown in FIG. 4, one end of a horizontal link 17 is fixed to the base of the cutoff lever 7 so that the other end projects horizontally, and one end of a connecting link 18 is rotatably attached to the other end. The other end of the connecting link 18 and the other end of the transmission lever 15 are connected by means of a stepped screw 19) whose stepped portion is loosely fitted into the circular arc hole 13c of the control lever 13.

As shown in FIG.
This branch piece 20) has two connecting parts 21 at one end.
The middle part of the actuating lever 21 forming the a and 21b is connected to the shaft 22.
A connecting rod that is rotatable by the shaft 22 and supported by a spring 23 wound around the shaft 22 while always applying a clockwise acting force, and that connects the connecting portion 21a and the other end of the transmission lever 15 to pass freely through the support base 1. 24/I, and the transmission lever 15 receives the acting force of the operating lever 21 through the connecting rod 24 in the counterclockwise direction (FIG. 4) centering on the step screw 16, and the transmission lever 15 and The stepped portion of the stepped screw 19 connecting the other end of the connecting link 18 is always connected to the control lever 13.
comes into pressure contact with the upper end of the circular arc hole 13c.

Further, a foot pedal 25 is disposed below the support base 1, and the other connecting portion 2 of the foot pedal 25 and the operating lever 21 is
1b is connected by chain 26.

In FIG. 3, a support shaft 27 is arranged at the lower left of the side surface of the sewing machine frame, and this support shaft 27 has an L provided at one end with a roller 28 that fits into the guide groove 10 formed on the surface side of the feed cam 11.
The middle part of the letter-shaped swinging link 29 is swingably supported, an electromagnet 30 is arranged in the sewing machine bed below, and the armchair 30a and one end of the swinging link 29 are connected by a chain 31. .

The sewing machine bed also has a guide shaft provided at its upper end with a track groove (not shown) for fitting into a longitudinal guide hole 9a (FIG. 6) provided in the substrate 9 and guiding the substrate 9 in the longitudinal direction. 32 is installed to be swingable about a vertical axis, and the guide shaft 32 and the other end of the swing link 29 are connected to the swing link 2.
When the guide shaft 9 swings, the guide shaft 32 is connected by the connecting link 33 so as to swing around the axis.

As shown in FIGS. 6 and 7, a guide body 37 with a needle hole 36 formed in the center thereof, through which the needle 35 of the needle bar 34 passes, is installed in the sewing machine bed in the sewing machine bed in a cylindrical shape above the bed surface. Further, a cloth support plate 38 is fixed to the tip of the substrate 9 to support the cloth at the sewing machine seam part, and the guide body 37 is arranged in a straight line in the left-right direction. A cam groove 39 that loosely fits around the outer periphery of the cam groove 39 is formed.

The base of a presser arm 40 whose tip extends below the chin of the sewing machine is fixed to the upper surface of the middle part of the base plate 9, and the tip of the presser arm 40 has a support that supports two upper and lower plates 41 and 42 in a vertically movable manner. The frame 43 is fixed, and the lower end of one of the upper and lower plates 41 is formed into a flat rectangle, and the cam groove 3 of the cloth support plate 38 is formed in the center of the frame 43.
A flat presser foot 44 having a linear needle hole 44a corresponding to the needle hole 44a and a large number of round holes 44b formed at regular intervals on the front and rear sides of the needle hole 44a is fixed, and the other upper and lower plates 42 are fixed.
An upper presser foot 45, which is formed into a flat rectangle having the same shape as the flat presser foot 44 and has a needle hole 45a corresponding to the needle hole 44a, is located at the lower end of the lower presser foot 44. When the upper presser foot 44 and the upper presser foot 45 overlap each other, round holes are formed on the lower surface of the upper presser foot 45 at positions corresponding to the round holes 44b of the flat presser foot 44 before and after the needle drop hole 45a. A plurality of needles 46 are fixedly arranged to protrude slightly from the lower surface of the flat presser foot 44 through 44b.

Further, the upper and lower plates 41 located within the support frame 43 are provided with elongated holes 47 in the vertical direction.
When these are overlapped (state A in Fig. 5), the lower end forms a short hole 48 that coincides with the long hole 47, and a step screw 49 (one side Only one side is rotatable and supported by 50 springs (only one side is shown).
The tips of the suppressing plates 51 and 51, which always apply a counterclockwise force (FIG. 3), pass through holes (not shown) provided in the rear end surface of the support frame 43, and then pass through the long holes 47 and the short holes 48. The upper and lower plates 41 and 42 are fitted with each other, and the above-mentioned force always applies a downward force to each of the upper and lower plates 41 and 42.

A horizontal shaft 52 in the left and right direction is rotatably supported in the middle part of the presser arm, and both ends thereof protrude from both sides of the presser arm 40, and one end thereof protruding from one side is curved upward. Attach one end of the pressing shaft 53 to the right end (Fig. 3).
The middle part of the rotating body 54 is fixed so that it projects horizontally in substantially the same direction as the horizontal axis 52, and the left end of the rotating body 54 and the pressing plate 51 are connected by a link 55 to rotate the rotating body 54 in the clockwise direction. As a result of the movement, the press plate 51 is connected so as to rotate clockwise.

On the other hand, one end of the connecting body 56 is fixed to the other end of the horizontal shaft 52 protruding from the other side of the presser arm 40, and the other end and the suppressing plate 5
1' is connected to the pressing plate 51'fJ5 so as to rotate in the same direction as the one pressing plate 51 through the rotation of the horizontal shaft 52 by the rotation of the rotating body 54 through a link 551.

Inside the sewing machine arm, a pair of hook-shaped links 57 are rotatably supported at their intermediate portions. Connected so as to cross this shaft 53, the left end of a horizontally long connecting plate 59 (
3), and the right end of the connecting plate 59 is interlocked with a presser foot control M mechanism 60 (not shown) installed on the rear end surface of the sewing machine frame.

This presser control mechanism 60 is the same as that described in Japanese Patent Application Laid-open No. 48-69648 filed by the present applicant, and is driven by the belt 4 on an intermittent shaft 61 rotatably supported on the machine frame. The rotation of a pulley (not shown) which is idly rotating in conjunction with the motor is transmitted to the intermittent shaft 61 via a spring clutch etc. interposed between the pawl body 62 installed on the intermittent shaft 61. The intermittent shaft 61 rotates due to the rotation of the intermittent shaft 61.
and the right end of the connecting plate 59 (
(not shown), the connecting plate 59 is moved in the left and right direction, and the flat presser foot 44° 45 on the upper shaft is moved up and down with respect to the upper surface of the cloth support plate 38 by the action described later. The intermediate portions are rotatably supported by a step screw 65, and are opposed to each other with the pawl body 62 sandwiched between their ends, and when one enters the engagement position with the pawl body 62, the other Two engaging bodies 63°6 are located at non-engaging positions and interrupt the interlocking movement between the pulley and the intermittent shaft 61 by engaging with the claw body 62.
4 and which has a weaker acting force than the spring 23 which applies a clockwise rotational force to the operating lever 21, the locking body 63 and the claw body 62 are always rotated counterclockwise. When engaged (double-dashed line in FIG. 4) to cut off the rotational transmission of the boo IJ- to the intermittent shaft 61, the connecting plate 59 stops at the left position, and at this time the elevating plate 58
The lower edge of is located at a position leaving a constant distance from the pressing shaft 53.

Further, when the operating lever 67 is rotated clockwise, the engagement between the locking body 63 and the claw body 62 is released, and the intermittent shaft 61 and the pulley are thereby interlocked to rotate the intermittent shaft 61. After half a rotation, the locking body 64 and the claw body 62 engage and the interlocking movement is interrupted again. During this period, the connecting plate 59 moves from the left position to the right position and stops. Each hook-shaped link 57 rotates counterclockwise and the elevating plate 58 descends, and from this descent, its lower edge pushes up the pressing shaft 53 and rotates the rotating body 54 clockwise, simultaneously pushing the horizontal shaft 52. The connecting body 56 also rotates through the link 55.
．． The suppression plates 51 and 51' are rotated clockwise through the upper and lower plates 41 and 55', and the tips of the respective upper and lower plates 41 and 51, which are engaged in the long holes 47 and the short holes 48 of 42, are raised. After raising the upper and lower plates 42 until the upper ends of their short holes 48 match the upper ends of the long holes 47 of the other upper and lower plates 41 (B in Fig. 5), both upper and lower plates 41 and 42 are moved simultaneously. Increase by a certain amount.

Therefore, the upper and lower insert feet 44.45 fixed at the lower end of each
After the presser foot 45 rises by a certain amount and rises from the upper surface of the flat presser foot 44, the flat presser foot 44 comes to rise together with the upper presser foot 45.

On the other hand, the other end of the clamping lever 67 and the other end of the operating lever 21 are connected by a chain 68 that loosely passes through the support base 1, so that the spring 2 is always
3, the operating lever 67 is pulled against the action force of the spring 66 to the solid line position in FIG. Concatenate to maintain.

As a result, the upper and lower inserting feet 44 and 45 are always maintained at a position elevated from the cloth support plate 38, as shown in FIG.

In FIG. 3, two support pieces 69 and 70 are installed on the sewing machine bed below the feed cam 11, and one support piece 69 has an engagement piece 7 that engages with the lower surface of one end of the swing link 29.
An elastic acting force (not shown) in a clockwise direction so that one end of the swinging piece 72 to which the link 1 is fixed can be rotated by a step screw 73, and the engaging piece 71 is always pressed against the lower end surface of the swinging link 29. The other end of the swinging piece 72 is movable in the lateral direction (left and right direction in FIG. 3) relative to the other supporting piece 70, and one end engages with the locking piece 14 of the transmission lever 15. An engaging body 76 provided with an engaging edge 74 and a fitting piece 75 projecting downward.
Rotatably connect the other end.

Furthermore, a fitting hole 77 for fitting the fitting piece 75 of the engaging body 76 is formed at one end on the sewing machine bed, and a locking piece 78 facing the lower end of the other end of the transmission lever is formed at the other end. A sliding body 79 having a shape formed thereon is arranged so as to be slidable in the lateral direction by means of stepped screws 80.

Further, on one side of the rear end of the presser arm 40 located behind the axis of the guide shaft 32, which is the center of horizontal swing of the board 9, a driven piece has a vertical plane that intersects the guide groove 9a of the board 9. 81 is fixedly arranged, and the board 9 is placed on the sewing machine bed surface near the rear end of the presser arm 40 at its final swinging position, that is, when the cycle sewing is completed and the board 9 is stopped (solid line position in FIG. 7). , so that the armature 82 protrudes opposite to and orthogonally to the plane of the driven piece 81.
This electromagnet 83 is fixedly arranged.

Further, as shown in FIG. 3, the first switch SW1 is arranged above the rear end of the side surface of the machine frame, and
An engaging piece 8 is provided on the outer periphery of the feed cam 11 and engages with the first switch SW2 during cycle sewing to close the contact point.
4 is fixedly arranged at a position close to the engaging portion 13b of the control lever 13, so that when the roller 13a of the control lever 13 is fitted into the recess 12a of the control cam 12, the contact point is closed by the engaging portion 13b. A second switch S front 2 is placed at the front of the second switch S.

When the contact point 2 in front of the second switch S is closed, the electromagnets 30 and 83 are excited for a predetermined time via a delay circuit (not shown), and the armature 30a of the electromagnet 30 is
is attracted downward, and the armature 82 of the electromagnet 83 is curved so as to protrude.

The present invention has the above structure, and its operation will be explained next.

When the sewing machine is stopped, as shown in FIG. 3, the roller 13a provided at one end of the control lever 13 fits into the recess 12a of the control cam 12, and the engaging portion 13b engages the contact point of the front 2 of the second switch S. The electromagnet 30 is energized and the chain 31 is closed.
The roller 28 at one end of the swing link 29 is connected to the feed cam 1 via
The swing link 29 is pulled so as to be located at the starting end 10a of the guide groove 10 of No. 1, the armature 82 of the electromagnet 83 protrudes, and the base plate 9, that is, the cloth support plate 38 and the upper flat presser foot 44
, 45 are located at the solid line position in FIG. 2 (the two-dot chain line position in FIG. 7), which is the starting position.

Also, an engagement piece 7 that engages with the lower surface of one end of the swing link 29
1 is pushed down against the clockwise acting force i of the rocking piece 72, and as a result, as shown in FIG. Locking piece 1
The locking piece 78 of the sliding body 79 is located outside the path of the bent end portion of the transmission lever 15 and faces the stepped portion 15a of the lower end edge of the transmission lever 15.

Furthermore, as described above, the operating lever 67 is in the solid line state in FIG. 4 due to the clockwise acting force of the operating lever 21 due to the spring 231, so that the locking body 64 and the claw body 62 are engaged with each other. As a result, the upper flat presser feet 44 and 45 are elevated from the fabric support plate 38.

Therefore, when the workpiece cloth W is pushed between the flat presser foot 44 and the cloth support plate 38 by the cloth feeding mechanism 3 and the foot pedal 25 is slightly depressed, the actuating lever 21 is moved counterclockwise through the chain 26. This causes the operating lever 67 to be released from traction via the chain 68, and the operating lever 67 is rotated around the stepped screw 65 to the position indicated by the chain double-dashed line by the force exerted by the spring 66, and its locking position is released. The engagement between the body 64 and the claw body 62 is disengaged, the rotation of the pulley idling on the intermittent shaft 61 is transmitted to the intermittent shaft 61, the intermittent shaft 61 rotates together with the claw body 62, and after half a rotation, The pawl body 62 engages with the locking body 63 to cut off the transmission, and the intermittent shaft 61 rotates half a rotation and stops.

This half rotation of the intermittent shaft 61 moves the connecting plate 59 to the left (FIG. 3), and the lifting plate 58 moves via the hook-shaped link 57.
rises.

Therefore, the pressing down of the pressing shaft 53 by the lifting plate 581 is released, so the pressing plates 51, 51 are rotated counterclockwise (FIG. 3) by the spring 50, and the upper and lower plates 41, 42 are lowered. The flat presser foot 44 descends onto the workpiece cloth W and the cloth support plate 3
8 (B in FIG. 5), the upper presser foot 45 is superimposed on the flat presser foot 44, and the tip of each needle 46 provided on the lower surface of the upper presser foot 45 is flat. Round hole 44 of presser foot 44
The workpiece cloth W is pierced through b to prevent the workpiece cloth from shifting.

Further, due to the rotation of the operating lever 21, the transmission lever 15 is slightly rotated clockwise via the connecting rod 24 around the step screw 16, and the step screw connecting the transmission lever 15 and the connection link 18 is rotated slightly. 19 is connected to the lower end of the circular shaft hole 13C of the control lever 13.

Therefore, when the foot pedal 25 is further depressed, the operating lever 21 is further rotated clockwise, and the transmission lever 15 is further rotated clockwise via the connecting rod 24, which is controlled by the stepped portion of the stepped screw 19. The lower end of the arcuate hole 13c of the lever 13 is pressed down, and the control lever 13 is rotated clockwise against the counterclockwise acting force, and the roller 13a provided at one end of the lever 13 moves from the recess 12a of the control cam 12. I'll leave it out.

On the other hand, due to the rotation of the transmission lever 15, the connecting link 1
8 and the horizontal link 17, the cutoff lever 7 rotates counterclockwise, and the rotation of the pulley 5, which is idling on the main shaft, is transmitted to the main shaft, and the sewing machine is driven.

The camshaft 8 rotates counterclockwise (FIG. 3) in conjunction with the rotation of the main shaft, and the feed cam 11 and control cam 12 rotate in the same direction.

If the foot pedal 25 is released after the control cam 13 has rotated, the roller 13a of the control lever 13 or the control cam 1
The outer periphery RI of 2 is engaged, and the control lever 13 is locked in the rotational position.Therefore, the transmission lever 15 is also locked in the rotational position, and the cutoff lever 7 is also rotated in the counterclockwise direction. maintained in the same state.

Further, by rotating the control lever 13, the engaging portion 1
3b separates from the contact of the second switch SW2, and the electromagnet 30
and 83 become inoperative, the suction maintenance of the swing link 29 is released, the roller 28 is guided by the guide groove 10 of the feed cam 11, the swing link 29 swings around the support shaft 27, and the electromagnet 83 The armature 82 is retracted into the electromagnet 83 by an elastic force.

As the swing link 29 swings, the guide shaft 32 swings about its vertical axis Jc via the connecting link 33, and the board 9 swings in the left-right direction.

In this embodiment, the base plate 9 is swung from the starting position shown by the two-dot chain line in FIG. The cam groove 39 moves while being guided by the guide body 37 of the sewing machine bed, and the circular arc movement of the fabric support plate 38 due to the swinging of the board 9 about the axis of the guide shaft 32 causes the linear cam groove 39 to move as shown in the guide body 37 of the sewing machine bed. Movement along the guide body 37 is canceled by the back-and-forth movement of the substrate 9, and therefore the cam groove 39 is formed in the workpiece cloth held between the cloth support plate 38 and the upper and lower inserts 44 and 45. A straight seam of the same length can be formed.

While the sewing machine is running, as the swing link 29 swings counterclockwise about the support shaft 27 while being guided by the guide groove 10 of the feed cam 11, the swing link 7
2 is rotated clockwise by the acting force, and as a result, the engaging body 76 moves leftward and its engaging edge 74 moves below the bent portion at the tip of the locking piece 14 of the transmission lever 15. At the same time, the sliding body 79 moves to the left via the fitting piece 75, and the locking piece 78 engages with the stepped portion 15a on the lower edge of the other end of the transmission lever 15, as shown by the two-dot chain line in FIG. from a position facing the base to a position facing the lower edge of the base.

Therefore, when the camshaft 8 rotates once, the roller 13a of the control lever 13 returns to the original position in the recess 1 of the control cam 12.
2a, the control lever 13 rotates counterclockwise around the stepped screw 16, and the pressing down of the stepped portion of the stepped screw 19 by the circular arc hole 13c is released, and the transmission lever 1
5 is also rotated counterclockwise about the step screw 16, and as a result, the cutoff lever 7 is rotated back clockwise via the connecting link 18 and the horizontal link 17, and the movement between the pulley 5 and the main shaft is cut off. The main shaft stops after rotating through a certain angle of inertia.

The rotation of the transmission lever 15 in the counterclockwise direction is performed at a position where the bent end portion of the locking piece 14 at one end abuts against the engagement edge 74 of the engagement body 76, as shown in FIG. is locked in
In this state, the stepped portion of the step screw 19 of the transmission lever 15 is engaged with the lower end of the circular arc hole 13c of the control lever 13, and the upper and lower insert feet 44 and 45 remain lowered onto the cloth support plate 38. It is.

In addition, when the control lever 13 returns to rotation, the engagement portion 13b-1 closes the contact point of the front 2 of the second switch S (at this time, the main shaft is rotating due to inertia), and this causes a delay. After a predetermined time, the electromagnets 30 and 83 are excited via the circuit (at this time, the inertial rotation of the main shaft is stopped,
The roller 28 of the swing link 29 is located at the end 10b of the guide groove 10), and the armature 30a is attracted,
The swing link 29 is rotated clockwise, and the roller 28 returns from the terminal end 10b of the guide groove 10 to the starting end 10at through the return path 10c, and connects the substrate 9 to the seventh via the connecting link 33 and the guide shaft 32. It returns to the starting position shown by the two-dot chain line in the figure.

At the beginning of the return rotation of the swing link 29, the armature 82 protrudes due to the excitation of the electromagnet 83.
pushes out the driven piece 81 of the presser arm 40 located at the opposing position, thereby applying a rotational force to the board 9 in the clockwise direction in FIG. 7 about the axis of the guide shaft 32.

This electromagnet 83 (the rotational force of the substrate 9 is applied to the substrate 9 by the return rotation of the swing link 29 by the electromagnet 30).
When the motor returns from the stop position shown by the solid line in FIG. 7 to the starting position shown by the two-dot chain line, it assists in smooth movement.

That is, due to the return of the swing link 29, the connection link 33
The board 9 returns to the starting position via the guide shaft 32, but the mounting resistance of the connecting parts from the swing link 29 to the board 9 and the sliding resistance between the board 9 and the bed surface. At the beginning of the return rotation of the swing link 29, it is necessary to return the swing link 29 with a large force, but at the beginning of the rotation, the armature 82 of the electromagnet 83 applies a return force to the board 9 in the direction of the starting position. By applying a return force to the board 9 in the direction of the starting position, the swing link 29 can be returned with a small force, and the return movement of the board 9 can be performed smoothly and quickly. .

The return rotation of the swing link 29 causes the swing piece 72 to rotate counterclockwise via the engagement piece 71, and the engagement body 76 moves to the right, so that the engagement edge 74 thereof is shown in FIG. Then, the locking piece 14 moves out to the right from the lower position of the bent portion at the tip thereof, and as a result, the locking piece 14 is released and the transmission lever 1
5 is rotated counterclockwise by the rotational force of the operating lever 21 until the step of the step screw 19 at the other end joins with the upper end of the circular arc hole 13c of the control lever 13, and the operating lever 21 is also rotated by the action force of the spring 23. Rotate back clockwise (Fig. 4) to the solid line position.

Therefore, the operating lever 67 is rotated clockwise against the spring 66 via the chain 68, and returns to the solid line state again, and as described above, the elevating plate 58 is lowered and the upper and lower inserting feet 44.45
rises from the cloth support plate 38.

Further, as the engaging body 76 moves to the right, the sliding body 79 moves to the right via its fitting piece 75, and its locking piece 78 moves to a position facing the stepped portion 15a of the transmission lever 15. do.

In addition, if the electromagnet 30 or the second switch S front 2 fails and the swing link 29 cannot be rotated back, the locking piece 78 of the sliding body 79 will close as shown in FIG. The transmission lever 15 remains at a position opposite to the lower line of the base, and even if the foot pedal 25 is depressed in this state, the transmission lever 15 is prevented from rotating clockwise by the locking piece 78t. It becomes impossible to drive the sewing machine 2.

Next, the control system for emergency stop of the sewing machine will be explained with reference to FIG.

In the figure, F is a flip-flop circuit, O8 is a one-shot multi-circuit, TR is a transistor, p is a photocoupler, M is a driving motor, S is an electromagnetic switch for controlling the driving and stopping of the driving motor, and IR is a power switch. This is a reset signal for resetting the flip-flop circuit when turned ON.

In the description of this control device, when the input/output voltage of each part is higher than a predetermined voltage, it is assumed to be a 1 signal, and when it is a low voltage, it is assumed to be a 0 signal.

Also, the one-shot multi-circuit O8 always outputs a 0 signal, but when the input signal changes from 1 to O, it outputs a 1 signal for a set time; When the contact point of the first switch SW1 arranged on the side surface of the machine frame is closed by the engaging piece 84 of the feed cam 11 during cycle sewing, the second switch S is opened by the engaging part 13b of the control lever 13 by the return rotation of the control lever 13. The time required for the first two contacts to close is set slightly longer.

First, when the power switch is turned on, each flip-flop circuit F1. F2 is reset, which turns on the transistor TR, closes the electromagnetic switch S, and drives the drive motor M.

When the sewing machine is driven by depressing the foot pedal 25 and cycle sewing is started, the contact of the first switch SW1 is closed by the engagement piece 84 of the feed cam 11 during the cycle sewing, and the flip-flop One-shot multi-circuit F is set, the input signal of one-shot multi-circuit O8 changes from 1 to O, and 1 signal is output for the set time.

When the control lever 13 returns to rotation upon completion of the cycle sewing, the second switch S is activated by the engaging portion 13b of the control lever 13.
When the first two contacts are closed, the flip-flop circuit F1 is reset, and immediately thereafter the output signal from the one-shot multi-circuit O8 changes from 1 to 0.

In this case, the flip-flop circuit F2 remains reset, the drive motor M continues to rotate, and the sewing machine 2
When the control lever 13 returns, the interlock between the pulley 5 and the main shaft is cut off and the pulley 5 is stopped, but the pulley 5 is interlocked with the drive motor M and idles on the main shaft.

Therefore, if the operator mistakenly continues to work while depressing the foot pedal 25, the control lever 13 will not be able to return even if the cycle sewing of the predetermined number of stitches is completed, and therefore the second switch SW2 Since the contact is not closed, the flip-flop circuit F1 remains set, and in this state, when the output signal from the one-shot multi-circuit O8 changes from 1 to O, a signal is output from the NAND circuit NAND1 and the flip-flop circuit F1 remains set. The pull circuit F2 is set,
As a result, the transistor TR is turned off, the contact of the electromagnetic switch S is opened, and the driving of the drive motor M is stopped.

In addition, when the drive motor M is stopped in this way, when re-driving it, first, the control lever 13 is returned to close the contact point of the second switch S front 2,
If the flip-flop circuit F1 is reset and the normally closed contact of the third switch SW3 is opened, the O signal is output from the NAND circuit NAND2 and the flip-flop circuit F2 is reset.

As described above, the present invention includes a start/stop means that drives a sewing machine by a movement operation in one direction and returns to the movement after forming a predetermined number of stitches to stop the sewing machine; A feed cam with one or more guide parts whose starting and ending ends are located at different distances from the center of rotation, and a guide part of the feed cam that extends from the starting end to the ending end between the start and stop of the sewing machine. The feed and recam has one or more guiding parts whose starting and ending ends are located at different distances from the fixed axis in a plane of rotation centered around a fixed axis, and from the drive of the sewing machine to the stop of the sewing machine. A rocking body that is guided from its start end to its end by a guide section of a feed cam and swings about a fixed axis, and a workpiece is held between a rocking body and a rocking body that is guided by a guide portion of a feed cam from its starting end to its trailing end. A cloth clamp holder that swings on the lower surface of the sewing machine base in conjunction with the five swinging bodies so that the first and last stitches are placed at different positions on the workpiece; A signal transmitting means for transmitting a predetermined signal in connection with the return to the working position, and a signal transmitting means interposed between the signal transmitting means and the driving motor, and after a predetermined number of stitches are formed (the predetermined signal from the signal transmitting means is transmitted to the starting pedal. 25, the cutoff lever γ is moved counterclockwise via the chain 26 etc., that is, to drive the sewing machine.
This is shown below, but the foot pedal 25 is used by worker I.
An operation such as pressing the switch (the contact point of the switch) may be closed, and the electromagnet excited thereby attracts the chain 26 etc. and rotates the cutoff lever 7.

Furthermore, in the above embodiment, the rotation of the pulley 5 is transmitted to the main shaft via the clutch mechanism and the cut-off control is performed by rotating the cutoff lever 7, which is rotatably arranged around an axis parallel to the main shaft. We have shown what was implemented in a cycle stitch sewing machine designed to do this, but for example,
As shown in Publication No. 25, at the rear end of the sewing machine,
The belt is placed on the main shaft via a belt shifter by rotating a cutoff lever that can be rotated around an axis perpendicular to the main shaft, and the main shaft and drive motor are linked by changing the hooks on the drive pulley and idle pulley as appropriate. It is also possible to carry out a cycle stitch sewing machine with a function of shutting off the sewing machine.

[Brief explanation of the drawing]

Fig. 1 is an overall perspective view of the suturing device, Fig. 2 is its top view, Fig. 3 is a right side view of the sewing machine, Fig. 4 is a rear end view of the suturing device centering on the sewing machine, and Fig. 5 is a top view of the suturing device. An enlarged sectional view taken along the line ■-v in Fig. 3, Fig. 6 an exploded perspective view of the cloth holding means,
FIG. 7 is a top view of the sewing machine bed, FIG. 8 is a control circuit diagram for emergency stop of the sewing machine, and FIG. 9 is a right side view corresponding to FIG. 3, showing only the rear end of the sewing machine. FIG. 10 is a front view of a feed cam showing another embodiment. Starting/stopping means...7, 13, Feed cam...11, Feed cam guide portion...10, Locking means...12, Rocking body...29, Cloth clamping means...9, 38, 44, 45
, return means...30, extrusion means...83, signal transmission means...SW2, blocking means -78, 79°

Claims (1)

[Scope of Claims] 1. A drive motor that is movable between an operating position where the rotation of the drive motor is transmitted to the main shaft to drive the sewing machine and an inactive position where the transmission is cut off, and which is always in the inactive position. a cutoff lever that receives the acting force of the sewing machine and moves to the operating position when the sewing machine is driven; and a guide that rotates around a fixed axis when the sewing machine is driven, and whose starting and ending ends are located at different distances from the center of rotation within the plane of rotation. a feed cam formed with one or more cams, a portion that engages with one end of the cutoff lever and maintains the cutoff lever in the working position against the acting force thereof in connection with the starting operation of the sewing machine, and a predetermined stitch. The feed cam has a cam surface consisting of a portion that allows the cutoff lever to move to the inactive position after formation.
A locking means rotates around a fixed axis in conjunction with the locking means, and a locking means rotates around a fixed axis while being guided from the start end to the end by the guide section of the feed cam between the time when the sewing machine is driven and stopped. a rocking body that grips the workpiece within the sewing area of the sewing machine, and slides on the sewing machine head surface in conjunction with the rocker so that the first stitch and the last stitch drop into different positions on the workpiece. a movable cloth holding means; a first switch disposed within the rotation path of the engaging piece fixed to the feed cam; and a first switch that engages with the engaging piece to generate a signal after the sewing machine is driven; and a return path for the cutoff lever. a second switch disposed above that generates a return signal when engaged with the cutoff lever, and a return signal from the second switch related to the return of the cutoff lever from the signal generation in relation to the signal from the first switch. A signal generating means that generates a signal for a certain period of time immediately before the signal is generated, and a signal generating means that generates a return signal from the second switch while the signal from the signal generating means is being generated, and a return signal that continues to be transmitted to the motor thereafter. A safety device for a cycle stitch sewing machine, comprising: a control circuit that maintains an energized state and cuts off energization to a motor when a return signal is not generated.