JPS6058994B2 - Clutch lever load reduction device for cycle sewing machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clutch lever load reduction device for a cycle sewing machine.

Conventionally, a cycle sewing machine as shown in FIG. 1 has been known.

This cycle sewing machine lowers the flower presser foot (not shown) by operating the operating lever 1 clockwise in the first stage, and moves the control lever 2 clockwise by operating the operating lever 1 clockwise in the second stage. The clutch lever 3 connected thereto is disengaged from the cam plate 4, and at the same time, the clutch 5 is engaged to rotate the main shaft 6, and a predetermined number of cloth feed cams 7 are rotated at a reduced speed in conjunction with the main shaft. The clutch lever 3 is rotated to operate a known seam forming mechanism (not shown), and the clutch 5 is disconnected by the return movement of the control lever 2 by the disconnection cam 8 supported coaxially with the cloth feed cam. engaging the plate 4 to stop the main shaft 6 at a predetermined rotational angle position;
This stops the stitch forming mechanism. However, in this type of cycle sewing machine, the control lever 2 is required to disengage the clutch lever 3 from the cam plate 4.
It was also necessary to manually pull the operating lever 1 to a predetermined rotation angle against the fairly strong elastic force of the spring S to start the seam forming mechanism.

As a result, there was a drawback that the worker's fatigue level increased and work efficiency decreased.

This invention was made in view of these drawbacks, and its purpose is to constantly tension the elastic body provided on the clutch lever by utilizing the rotational movement of the control lever. By applying the elastic force of the elastic body to the clutch lever and releasing the tensile state of the elastic body when the clutch lever is started, the elastic force of the elastic body acting on the clutch lever is reduced, and the elastic force of the elastic body is reduced when the cycle sewing machine is started. To provide a load reduction device for a clutch lever in a cycle sewing machine that reduces the burden on a worker.

Hereinafter, one embodiment of the present invention will be described based on the drawings.
The illustrated embodiment is applied to a cycle sewing machine in which the presser foot is mechanically lowered by depressing a single operating lever to its initial position, and the sewing machine is started by depressing it to the lowest position beyond the initial position. This is what I did.
Note that the same parts as in the conventional example are given the same reference numerals.

FIG. 2 shows a known presser mechanism, in which 8 is a pet 9.
A board is provided on the upper surface so as to be able to slide left and right and rotate around the right end using a cloth feeding cam 7, 10 is a cloth support provided at the tip of the board 9, 11 is a curved support frame provided on the board 8, and 12 is a support frame provided on the board 8; The fabric support 1 is a fabric presser foot supported vertically movably at the tip of the supporting frame 11.
It is facing 0. This presser foot 12 engages with the tip of the press plate 14 by the force of a spring 13 and constantly receives a downward force, and also has a rotating body 16 connected to the press plate 14 by a link 15. It is designed to move upward by rotating in the direction. 17, 17 is an L-shaped link rotatably provided inside the sewing machine arm 18, 19 is a pressing body provided at one end of the L-shaped links 17, 17, 20 is a link 17,
A connecting rod 21 provided at the other end of 17 is an L-shaped arm rotatably provided on the sewing machine body, one end of which is connected to the connecting rod 20, and the other end forms a fork 22.

When the L-shaped arm 21 is normally rotated counterclockwise by a coil spring (not shown) stretched between the arm 18 and the connecting rod 20 (see Fig. 2), the presser foot 12 supports the cloth. When the upper surface of the cloth support 10 is pressed and the L-shaped arm 21 rotates clockwise, the cloth presser foot 12 resists the spring 13 and presses the upper surface of the cloth support 10.
Place it away from the Next, in Figures 1, 3, and 4, 6 is the aforementioned main shaft, which is rotatably supported on the sewing machine body! However, it can be connected to and separated from the drive source via the clutch 5.

Reference numeral 3 denotes a clutch lever rotatably supported on a fixed axis centering on a shaft 3A provided on the sewing machine body, and the clutch lever 3 is detached from the cam plate 4 at the same time as the clutch 5 is connected and activated by forward movement in the counterclockwise direction. The main shaft 6 is rotationally driven, and the clutch 5 is disconnected by the clockwise return motion, and at the same time, the cam plate 4 is engaged to stop the rotational drive of the main shaft 6.

Reference numeral 2 denotes an L-shaped control lever rotatably supported on a shaft 2A fixed horizontally and perpendicular to the shaft 3A at the rear lower part of the arm 18, and at the upper end thereof, the lever rotates at a deceleration speed in conjunction with the main shaft 6. It has a mouth 23 that joins to the outer circumferential surface of the cutoff cam 8, and has a vertically elongated hole 24 in the horizontal part, and the horizontal end is connected to the clutch lever 3 via a connecting member 25.

In conjunction with this clockwise unidirectional movement of the control lever 2 (FIG. 1), the clutch lever 3 is moved forward and the main shaft 6 is rotated, and after a predetermined rotation of the cutoff cam accompanying the rotation of the main shaft 6, the clutch lever 3 is moved counterclockwise. The rotation of the main shaft 6 is stopped by moving the clutch lever 3 back in the direction shown in FIG. 1
29 is an actuating lever whose base end is rotatably supported on the shaft 2A of the control lever 2, and has a step screw 27 and an L-shaped rod 28 loosely fitted in the long hole 24 of the control lever 2 in the middle part; 29 is an arm 18; By means of a coil spring provided between the L-shaped rod 28 and the L-shaped rod 28, the operating lever 1 is normally rotated counterclockwise in FIG. It works like this.

The arm 18 on the right side of the clutch lever 3 (FIG. 3) is equipped with a known control device 30 (see FIG. 5) that moves the presser foot 12 up and down, as shown in Japanese Patent Laid-Open No. 48-6964 (see FIG. 5). Provided in connection with 1.

That is, the engaging portion 32 of the second control lever 31 is normally pressed upward in FIG. The gear 36 is in the state shown in FIG. 3, and in this state, the gear 36 idles in conjunction with the drive source via the free P1 gear G, and the operating lever 1 is moved to the first position where the step screw 27 contacts the lower end of the elongated hole 34. When the L-shaped rod 28 is rotated clockwise against the spring 29 up to the stage, the L-shaped rod 28 also rotates, and the second control lever 31 also follows the L-shaped rod 28 counterclockwise due to the tensile force of the spring 35. The rotating claw 33 is removed from the movement path of the claw 34a of the rotating body 34. As a result, the clutch spring 35 shown in FIG. When rotated to 180 degrees, its pawl 34a engages with the pawl portion 31a of the second control lever 31, and they stop at that position. As the second control lever 31 is displaced to the two positions described above, the shaft 37 rotates approximately 180 degrees at a time, and at this time, the eccentric cam 39 provided at the tip of the shaft 37 moves the sliding body 40 along the guide groove of the arm 18. FIG. 5 The L-shaped arm 21 is controlled to move in the vertical direction and rotated at a certain angle in two directions via the square piece 41 fitted to the forked portion 22 of the L-shaped arm 21. It is starting to move downward. 41 is a guide rod fixed to the sewing machine body, and this guide rod 41 has a locking member 4 having a locking portion 42a.
2 is loosely fitted in a direction perpendicular to the axis of the shaft 3A of the clutch lever 3 so as to be able to reciprocate.

S is a spring as an elastic body having one end connected to a horizontal rod 3a provided on the clutch lever 3 and the other end connected to the upper end of the locking body 42; 43, one end rotatably attached to the sewing machine body near the operating lever 1; This is a link whose other end is rotatably connected to the lower end of the locking member.

44 is an arm rod whose base end is provided at the upper end of the control lever 2 and whose free end extends above the link 43, as shown in FIG. When moved, the link 43 is pushed down clockwise to move the locking body 42 in the direction in which the spring S is pulled.

45 is rotatably supported by the sewing machine body, and is always supported by spring 4.
6, which is rotated clockwise by a rolling element 6, and has a roller 45a at the upper end that comes into contact with a cam body 47 fixed to the shaft 37 of the control device 30 shown in FIG. 5, and a locking body at the lower end. 42
It has a pawl 45b that engages with the locking portion 42a when it reaches the lowest position.

That is, this rolling element 45 engages with the locking body 42 when the spring S is pulled and the locking body 42 is at the lowest position, and maintains the tensioned state of the spring S, thereby causing the clutch lever 3 to have the spring S tightened. It applies elastic force and rotates counterclockwise upon contact with the cam body 47 to release the engagement with the locking body 42 and reduce the elastic force of the spring S acting on the clutch lever 3. It is.

Next, the operation of this embodiment will be explained.

FIG. 6A shows the state of each component when the operating lever 1 is not operated, that is, when the sewing machine is not operating.

In this state, the second control lever 31 is prevented from rotating counterclockwise by the L-shaped rod 28, and in this state, the claw 34a of the rotating body 34 and the claw 33 are engaged, and the rotating body
4 is stationary.

Furthermore, the locking body 42 is located at the lowermost position, and the pawl 45 of the rolling element 45
a is locked to the locking portion 42a, and applies the tensile force of the spring S to the clutch lever 3.

Furthermore, as shown in FIG. 6A, the roller 23 of the control lever 2 falls into the lower part A of the cutoff cam 8, rotates the control lever 2 counterclockwise, and connects the clutch lever 3 to the cam plate via the connecting member 25. While being rotated in four directions, it is firmly engaged with the cam plate 4 by the tensile force of the spring S.
At the same time, the clutch 5 is disconnected and the main shaft 6 is stopped.

Next, as shown in FIG. 7, when the foot pedal is depressed one step, the step screw 27 of the operating lever 1
When the L-shaped rod 28 is rotated downward until it touches the lower end of 4,
also moves downward against the elastic force.

As a result, the second control lever 31, which is always receiving a counterclockwise rotational force from the spring 35, also rotates counterclockwise to follow the L-shaped rod 28. Therefore, the pawl 33 is disengaged from the pawl 34a of the rotary body 34, and the rotary body 34 rotates 1800 times together with the shaft 37, and the pawl portion 31a of the second control lever 31 is rotated 1800 times.
The claw 34a engages and stops. Therefore, as shown in FIG. 5, the sliding body 40, which has been in the downward position due to the eccentric cam 39, moves upward due to the 1800 revolutions of the eccentric cam 39, and the L-shaped arm 21 is moved upward as shown in FIG. The presser foot 12 is rotated counterclockwise to lower the presser foot 12 and press and hold the fabric to be sewn. Also, in connection with the 180 rotation of the rotating body 34, the cam
The body 47 also rotates by 180 degrees, and while the cam body 47 is rotating, the cam body 4
7 comes into contact with the roller 45a of the rolling element 45 and rotates it counterclockwise.

Then, the engagement between the locking body 42 and the rolling element 45 is released, the locking body 42 moves upward, and the link 43 also rotates counterclockwise. Therefore, the spring S returns to almost its natural length, and the elastic force of the spring S no longer acts on the clutch lever 3.

Next, when the foot pedal is further depressed from the state shown in FIG. 7, that is, when the operating lever 1 is further rotated, the lower end of the elongated hole 24 engages with the step screw 27, as shown in FIG. 8A. Rotate the control lever 2 clockwise.

Then, the clutch lever 3 rotates counterclockwise via the connecting member 25 as shown in the opening in FIG. Rotate cam 8. At this time, the force applied to the operating lever 1 when rotating the control lever 2 is only the elastic force of the spring 29, and the elastic force of the spring S does not act, so the operating lever 1 can be easily pulled.

Thereafter, when the roller 23 of the control lever 2 comes into contact with the circumferential opening of the cutoff cam 8, the control lever 2 further rotates clockwise, thereby also rotating the arm rod 44 and moving the link 43 as shown in FIG. Rotate clockwise from the state shown in FIG. 8.

Therefore, the locking body 42 moves downward against the spring S, and the pawl 45b of the rolling element 45 and the locking portion of the locking body 42, which are always receiving a clockwise acting force due to the elastic force, move downward. 42
a engages to prevent upward movement of the locking body 42 and apply the elastic force of the spring S to the clutch lever 3. After that, when the cut-off cam 8 makes one revolution, the control lever 2 re-enters the lower part A of the cut-off cam 8 as shown in FIG. 3 is restored, the clutch 5 is disconnected, and after cutting off the interlock between the drive source and the main shaft 6, it engages with the cam plate 4 and the main shaft 6
At the same time, the operating lever 1 also returns to its original position, and the second control lever 31 is rotated counterclockwise via the L-shaped rod 28 against the spring 35. Therefore, the engagement between the pawl 31a and the pawl 34a is released, and the rotating body 34 moves between the pawl 33 and the pawl 31a.
The shaft 37 rotates 1800 times until it engages, and as a result, the shaft 37 also rotates 180 degrees.
Then, as shown in FIG. 5, the sliding body 40 is moved downward. For this reason,. The presser foot 12 moves upward, and each component returns to the state shown in FIG. 6 before starting. Furthermore, the top of the presser foot 12
The cam body 47 is used when the downward movement is not performed using the driving source of the sewing machine as in this embodiment, but is performed using a dedicated operating lever for upward and downward movement of the presser foot against spring pressure by human power. It is not necessary to rotate the rotor 45 by using the lever, but a mechanism may be used that releases the engagement between the rotor 45 and the locking body 42 in conjunction with the operation of this operating lever.

Further, the operation of the roller 45 does not have to be associated with the operation lever for moving the presser foot up and down, and may be operated manually using a separate actuation means. Further, instead of the link 43, the arm rod 44 may be extended to directly engage the locking body 42, and the rolling element 45 is also not always rotated clockwise using the spring 46. Alternatively, the center of gravity may be changed by changing the center of rotation, thereby always rotating clockwise.

As explained above, according to the present invention, the elastic body provided on the clutch lever is normally pulled using the rotational movement of the control lever, thereby imparting the elastic force of the elastic body to the clutch lever, and the clutch By releasing the tensile state of the elastic body when the lever is started, the elastic force of the elastic body acting on the clutch lever is reduced, which reduces the operator's operating force when starting the cycle sewing machine. This has the effect of reducing work fatigue and improving work efficiency.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the main parts of a conventional cycle sewing machine, FIG. 2 is a cross-sectional view of the main parts of the presser mechanism of the cycle sewing machine, FIG. 3 is a front view of an embodiment of the device of the present invention, and FIG. 3 is an exploded perspective view of the device shown in FIG. 3, FIG. 5 is a partial sectional view of the control device 30, and FIGS. 6 to 8 are explanatory views of the operation of the device shown in FIG. 3. 2...Control lever, 3...Clutch lever, 6...
- Main shaft, 8... Shutoff cam, 42... Locking body, 42a
... Locking part, 44 ... Arm rod, 45 ... Rolling element, S
...Elastic body.

Claims (1)

[Claims] 1. A main shaft rotatably supported on the sewing machine body and capable of approaching and separating from the drive source via a clutch, and a free end that engages the clutch in forward motion to drive the main shaft rotationally, and disengages the clutch in backward motion. A clutch lever that engages the clutch and whose base end can be rotated around a fixed axis, a cut-off cam that is linked to the main shaft and rotates at a deceleration speed, and a clutch lever that moves in one direction in conjunction with manual operation to operate the clutch lever. A control lever capable of reciprocating with the clutch lever so that it moves forward and follows the cutoff cam after a predetermined rotation of the main shaft, returns after a predetermined rotation of the cutoff cam, and moves the clutch lever backward, and a locking portion. A locking body that is capable of reciprocating along a straight line that separates from and intersects with the rotational axis of the clutch lever, an elastic body that spans between the clutch lever and the locking member, and a follow-up and shutoff cam of the control lever. an arm rod that moves the locking body in a direction that tensions the elastic body in relation to the rotational movement; a rolling element that can engage with a locking portion of the locking body at a specific position where the elastic body is always tensioned; A clutch lever load reduction device for cycle sewing machines.