JPS6121023Y2 - - Google Patents

Description

[Detailed description of the invention] This invention has a perfect circular part and a perfect circular part on the outer periphery that rotate at a reduced speed in synchronization with the main shaft of the sewing machine and engage the control lever to maintain the interlocking state between the main shaft and the driving part of the sewing machine. Regarding a control device for a cycle sewing machine, the control cam continuously forms a concave portion that maintains the main shaft of the sewing machine in a stopped state, especially during the formation of a predetermined number of stitches when the control lever moves from the concave portion of the control cam to the perfect circle portion. The present invention relates to a control device for a cycle sewing machine that drives the main shaft of the sewing machine at a low speed.

Conventionally, in high-speed cycle sewing machines, when the main shaft is brought up to high speed from a stopped state in a short period of time, loads and shocks are applied to each operating mechanism linked to the main shaft, damaging various parts or accelerating wear, which can cause the sewing machine to fail. In order to shorten the life of the sewing machine and prevent the thread from falling out at the beginning of sewing, the main shaft is driven at a low speed during the formation of a predetermined number of stitches at startup to buffer the shock at the start-up.

Examples of configurations for this purpose include, for example, Japanese Patent Publication No. 54-2129 and Japanese Patent Publication No. 56-2012 related to patent applications filed by the present applicant.
13480 is known, and according to this, as shown in FIG. 1, a control cam 10 that rotates counterclockwise with a constant reduction ratio with respect to the main shaft has a true circular portion 11 on the outer periphery. , a lower part 12, 14 which is continuous with the perfect circular part 11 and has a smaller diameter than the true circular part, and a recessed part 13 which is continuously recessed in both the lower parts are provided to connect the main shaft 1 and the driving part (not shown). When the pin 7a of the control lever 7 that enables the operation of the disposed clutch means engages with the circular portion 11, the main shaft 1 is rotated at high speed, and when the pin 7a engages with the lower portions 12 and 14, the main shaft 1 is rotated. When the pin 7a engages with the recess 13 by rotating at a low speed, the interlocking movement between the main shaft 1 and the driving section is cut off. That is, when the cycle sewing machine is inactive, the pin 7a of the control lever 7 is engaged with the recess 13, and when the sewing machine is started, the control lever 7 is moved clockwise (FIG. 1) to shut off the clutch means. When the state is released and the main shaft 1 starts rotating, the control cam 10 rotates counterclockwise, so the pin 7a of the control lever 7 first engages with the front lower part 14, and the sewing machine enters a low-speed driving state. When the pin 7a of the control lever 7 rides on the circular part 11 from the lower part 14 while contacting the inclined part 14a due to the rotation of the control cam 10, the sewing machine enters a high-speed driving state. A low-speed drive period will be set.

However, the amount of penetration resistance when the needle penetrates the fabric varies depending on the thickness of the fabric, and when sewing thick fabric, the penetration resistance of the needle is large, so in order to reduce collisions with each operating mechanism, it is necessary to It is necessary to lengthen the low-speed drive period set in the angle range of 14. On the other hand, when sewing thin cloth, the low-speed drive period can be set short because the penetration resistance of the needle is small.

For this reason, in the past, it was necessary to install control cams with different angle ranges for the lower part depending on the thickness of the material to be sewn, which made replacing the control cams troublesome and required multiple control cams. The disadvantage is that the cost increases because it has to be done.

In addition, in FIG.
When the pin 7a of the control lever 7 is engaged with the inclined portion 14a between When the needles penetrate at the same timing, the main shaft 1 is not receiving any driving force, so the main shaft 1 is moved by the penetration resistance of the needle.
The sewing machine may stop, and this requires the troublesome operation of manually operating the clutch means to open both sides of the sewing machine drive.To prevent this, the above-mentioned idling state and the timing when the needle penetrates the fabric are necessary. It is necessary to perform an operation to shift the coincidence between the two, but in the past, the only way to do this was to change the control cam. This invention aims to eliminate these drawbacks.

The embodiment of this invention will be explained below with reference to the drawings.
This is based on the one described in Japanese Patent No. 13480, and a stop body 2 and a stop groove 2a (Figs. 3 to 5) are formed at the rear tip of the main shaft 1 rotatably supported on the machine frame. The pulley 3 rotates in conjunction with a driving body (not shown) and is movable in the axial direction, and is always subject to an elastic force to the right in FIG. 1, and the rotation of the pulley 3 can be transmitted to and interrupted by the main shaft 1. Clutch 4 is supported.

A control body 38 supported on the rear surface of the machine frame and provided with a locking claw 38a at the upper end is arranged in relation to the clutch 4 according to the configuration described in Japanese Patent Publication No. 54-2129, and controls the interlocking of the pulley 4 and the main shaft 1. There is a cutoff position (Fig. 5) where the rotation of the pulley 4 is decelerated and transmitted to the main shaft 1, and the main shaft 1 is rotated at a low speed (the fourth position).
(Fig. 3) and a high-speed position (Fig. 3) where the rotation of the pulley 4 is transmitted to the main shaft 1 without deceleration and the main shaft 1 is rotated at high speed.

A roughly wedge-shaped control lever 7, whose center is supported swingably about a fixed axis on the front of the machine frame by a support shaft 6, is connected at its right end (Fig. 1) to a control body 38, and is always rotated counterclockwise. A first position in which the control body 38 is held in the cutoff position by receiving an acting force in the direction (FIG. 1), and a second position in which the control body 38 is rotated clockwise from the first position and held in the low speed position. and a third position in which the controller 38 is rotated clockwise from the second position to maintain the control body 38 at a high speed position. An operating lever 8 whose one end is rotatably supported on a support shaft 6 has an intermediate portion attached to a control lever 7.
The other end is connected to an electromagnetic solenoid (not shown) and a pedal (not shown).

At the front of the machine frame, a feed cam 9 that rotates counterclockwise at a fixed reduction ratio in conjunction with the main shaft 1 about a fixed axis parallel to the support shaft 6 is fixed, and a control cam 21 is mounted on the same axis. (Figures 6-8) are fixed. The pin 7a of the control lever 7 is engaged with the outer peripheral surface of the control cam 21, and the control lever 7 is connected to the outer peripheral surface of the control cam 21.
a perfectly circular part 11 that holds the part in the third position;
a recess 1 for holding the control lever in the first position;
3 will be provided. Note that the lower part 15 on the activation side of the control cam 21 is formed over a sufficiently wider angular range than the lower part 14 of the control cam 10 (FIG. 1).

Further, as shown in FIG. 6, a notch 15a is provided that stands up from the surface of the lower portion 15 and forms a wall surface 15b parallel to the rotational direction of the control cam 21.

A screw hole 20 is bored in the side surface of the control cam 21 within the rotational angle range corresponding to the lower part 15 on the starting side, and a notch is formed so that the upper surface has a height that matches the perfect circular part 11 and is slidable on the wall surface 15b. The adjustment body 16 provided with the surface 16b has a mounting portion 17 formed with a long hole 18 that extends along the circumferential direction of the control cam 21 and communicates with the screw hole 20, and the adjustment body 16 is attached to the upper surface of the lower portion 15. The control cam 21 is movable along the circumferential direction of the control cam 21, and the screw hole 20 is connected to the elongated hole 18.
The adjusting body 16 is fixed on the lower part 15 by screwing the screw 19 into the lower part 15.

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

First, when sewing thick fabric, loosen the screw 19 and tighten the edge 15c (6th to 8th) of the lower part 15 on the starting side.
The rotation angle from FIG. The adjusting body 16 is moved to the upper surface of the lower part 15 so that the timing of idle rotation of the main shaft 1 when the needle engages with the front end surface 16c does not coincide with the timing when the needle penetrates the cloth (see Fig. 8), and the length Hole 18
The adjusting body 16 is fixed in the position shown in FIG. 8 by connecting the double-sided screws 19 to the screw holes 20.

In this way, when the pedal (not shown) is depressed, the control lever 7 is moved clockwise via the operating lever 8 to the second position, the pin 7a is disengaged from the recess 13, and the control body 38 is moved to the low speed position (fourth position). As the main shaft 1 begins to rotate, the control cam 21 rotates counterclockwise and the pin 7
a engages with the lower part 15 on the starting side, and the sewing machine is maintained at low speed.

When the control cam 21 continues to rotate counterclockwise due to continued low-speed driving, the pin 7a of the control lever 7 comes into contact with the front end surface 16c of the adjustment body 16, and the control cam 2
1 rotates further, the pin 7a climbs up the front end surface 16c and comes to engage with the upper surface 16a, so the control lever 7 moves to the third position and the control body 5 moves to the high speed position (fifth position). (Fig.) and spindle 1
rotates at high speed. However, the rotation angle range of the lower portion 15 up to the front edge 16c of the adjuster 16 is sufficiently wide as shown in FIG. Even if the pin 7a of the control lever 7 is large, the front edge 1 of the adjustment body 16
Since the shaft 1 has attained a sufficient rotational speed when it comes into contact with the shaft 6c, the impact force applied to each operating mechanism of the sewing machine during this changeover from low-speed rotation to high-speed rotation is not large.

Then, the pin 7a of the control lever 7
When the control cam 21 rotates approximately one revolution while being engaged with the
When the control cam 21 rotates, the pin 7a engages with the recess, and the control body 5 is moved to the cutoff position (first position) via the control lever 7. 3), the sewing machine stops and one cycle of sewing is completed.

As described above, according to this invention, an adjusting body is attached to the upper surface of the recess of the control cam corresponding to the low-speed drive period after startup so as to be movable along the circumferential direction of the control cam, and the adjusting body is moved. Since the low-speed drive period after startup can be adjusted, it is possible to
When sewing a material that has a high resistance to the needle, set the low-speed drive period as long as shown in Figure 8, and then switch to high-speed drive after the main shaft has achieved sufficient speed to operate the sewing machine. In addition to reducing the impact force on the mechanism, when sewing materials with low resistance to the needle, such as thin cloth, the low-speed drive period can be set short and the high-speed drive can be started quickly, as shown in Figure 7. By switching, the time required for one cycle can be shortened and work efficiency can be improved.

In addition, since any low-speed drive period can be set with a single control cam, there is no need to prepare multiple control cams as in the past, eliminating the need to replace control cams and reducing costs. effective.

Furthermore, as mentioned above, even if the time when the spindle idles coincides with the time when the needle penetrates the fabric, and the sewing machine stops driving, it is possible to change the timing between both times by simply moving the adjustment body slightly. Since the drive can be stopped so that the two do not match, the adjustment operation is extremely easy.

[Brief explanation of the drawing]

Figure 1 is a front view of the control device of a cycle sewing machine.
Figure 2 is a diagram showing the concave portion of a conventional control cam;
4 and 5 are right side views of the stop mechanism, FIG. 6 is an exploded perspective view of essential parts of the control cam of the present invention, and FIGS. 7 and 8 are views showing the adjustment state of the control cam. 2, 3, 4, 5...Clutch means, 7...Control lever, 11...Perfect circular portion, 15...Low portion, 13
... recess, 21 ... control cam, 16 ... adjustment body.

Claims (1)

[Claims for Utility Model Registration] A high-speed state where the rotation of the driving part is transmitted to the main shaft so as to drive the main shaft of the sewing machine at high speed, and a state where the rotation of the driving part is decelerated and transmitted to the main shaft so that the rotation is slower than the high-speed state. a clutch means interposed between the driving part and the main shaft so as to be switchable between a low speed state and a cutoff state for cutting off interlocking between the drive body and the main shaft; a first position for putting the clutch mechanism in the cutoff state; A control lever is arranged in relation to the clutch mechanism so as to be movable between a second position in which the clutch mechanism is in a high speed state and a third position in which the clutch mechanism is in a high speed state. It is supported on the machine frame so as to rotate, and has a perfect circular part formed on the outer periphery equidistant from the center of rotation to hold the control lever in the third position, and a perfect circular part formed on the outer periphery to hold the control lever in the first position. a control cam having a concave portion recessed toward the center of rotation; and a low portion connected to the circular portion and the concave portion and formed at an intermediate center distance between the two so as to hold the control lever in the second position. In a cycle sewing machine, an adjusting body whose outer periphery has the same center distance as the true circular part of the control cam and can be moved and locked in the circumferential direction along the lower part so that the control lever moves from the second position to the third position. A control device for a cycle sewing machine, characterized in that it is provided with.