JPS637026Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to an improvement of a cloth feeding device for a blind stitch sewing machine.

In conventional blind stitch sewing machines, when changing the amount of cloth fed by a feed dog attached to a feed table, the amount of eccentricity of an eccentric crank that swings the feed table using the frame body as a fulcrum is adjusted. In this case, first stop the operation of the sewing machine, then operate the pushbutton, turn the pulley by hand to change the angle, and change the amount of eccentricity of the eccentric crank to change the desired feed amount, or Remove the cover containing the eccentric crank, loosen the set screw on the eccentric crank with a screwdriver, etc., turn the pulley by hand to change its angle, and when the desired feed amount is reached, tighten the set screw on the eccentric crank again with a screwdriver, etc. This required complicated operations.

By the way, when sewing the pocket with a blindstitch sewing machine, the only way to sew the pocket is to sew at a constant feed rate at the beginning and end of the step-stitched part of the pocket. In order to prevent it from cutting and fraying, this part is hand-sewn in a separate process to bar-tack, or a special blind-stitch bar-tack sewing machine called a dotsuking sewing machine is used to perform reinforcement sewing work. It was on. However, these methods not only significantly hinder work efficiency, but also
I couldn't get beautiful seams.

In addition, since blind stitch sewing machines use chain stitch, if the last stitch frays, the entire stitch frays, but conventionally the needle is stopped at the top dead center to prevent the needle from breaking. After that, the fabric was pulled forward to cut the thread, and when the thread was cut, the sewing was completed, and no special tacking was done.

However, with this method, when the fabric is stretched, the seam threads are pulled, causing the beautiful seams to shrink, reducing the value of the product and causing the threads to fray.

For this reason, after cutting the thread, it is necessary to manually tie the end of the thread to make a knot, or at the end of sewing, operate the pedal to remove the presser foot from the throat plate. By separating them and reducing the amount of cloth fed, the stitches are sewn in close overlaps to prevent fraying. However, in the former case, the work efficiency is low because it is done manually, and in the latter case, the presser foot is moved away from the throat plate to sew, so the fabric is not held stably, and the fabric thickness, material, feed rate, etc. Due to variations in quantity and operator handling, it has not been possible to achieve consistent, perfect locking stitches.

The present invention is a back-and-forth feed that changes the amount of cloth feed by attaching a sub-feed with a feed dog to the main feed, and changing the amplitude of the swinging motion of the sub-feed supporting rod that supports the sub-feed. Move the adjustment crank up and down,
The above problem was solved by attaching a rotatably attached feed adjustment slider to the feed adjustment slider crank so that it could slide up and down. The object of the present invention is to provide a cloth feeding device for a sewing machine that can steplessly change the stroke of cloth feeding from a cloth feeding state to tacking stitching.

Hereinafter, the present invention will be explained based on the drawings.

1 to 13 show an embodiment of the present invention, in which reference numeral 1 is an upper shaft, and 2 and 3 are eccentric cranks. These eccentric cranks 2 and 3 are well known, and are adapted to apply a swinging motion to the main feed table 4 in response to the rotation of the upper shaft 1. This main feed base 4 has a root end that is connected to the upper shaft 1 mentioned above.
It is supported by the eccentric cranks 2 and 3, and approximately midway between the free end and the root end is rotatably supported by a main feed stand support pin 6 fixed to the main feed stand 4 with a screw 7. There is. The lower end of the main feed support rod 5, which is rotatably attached to the main feed support pin 6, is connected to the feed adjustment slider crank 1 by means of a screw 12.
It is fixed to the crankshaft 11b of No. 1. The crankshaft 11b is rotatably attached to a bearing bushing 10 that is press-fitted into the frame body 8 and fixed with screws 9. That is, the main feed base support rod 5 is configured to swing relative to the frame body 8 using the crankshaft 11b as a fulcrum, thereby causing the main feed base 4 to swing up and down and back and forth.

Also, approximately midway between the root end of the main feed base 4 and the main feed base support rod 5, there is a sub-feed base support rod 18 that rotates with a support rod pin 17 fixed by a screw 16 as a fulcrum. It is attached freely. At the tip of this sub-feed support rod 18,
A sub-feed transmission pin 19 is fixed by a screw 20, and a sub-feed table 15 and a sub-feed transmission rod 21 are rotatably attached to the sub-feed transmission pin 19. In addition, the above sub-feed transmission pin 1
At 9, a collar 22 which is brought into close contact with the boss end face of the sub-feed transmission rod 21 is fixed by a screw 23.

A sliding body 14 is rotatably attached to the core pin 13 fixed to the free end of the main feed table 4 by a screw 12a, and the sliding body 14 and the sub-feed table 15 slide into the groove 15a. It is set freely. The core pin 13 attached to this sliding body 14 has
A washer 26 is inserted so that movement of the sub-feed table 15 in the axial direction is restricted. Also,
A feed dog 24 is fixed to the tip of the sub-feed table 15 with a screw 25.

On the other hand, a forward/backward feed adjustment arm 28 that rotates around a transmission shaft 27 rotatably supported by the frame body 8 is fixed to the transmission shaft 27 with a screw 29 . A longitudinal feed adjustment crank 30 is rotatably attached to one side of the longitudinal feed adjustment arm 28, and a collar 31 is fixed to the other side by a screw 32, and a longitudinal feed adjustment crank 30 is attached to the other side of the longitudinal feed adjustment arm 28.
0 is restricted from moving in the axial direction. Further, the tip of the sub-feed transmission rod 21 is rotatably connected to the upper shaft of the longitudinal feed adjustment crank 30, and a feed adjustment slider 33 is rotatably attached. The feed adjustment slider 33 is slidably fitted into the groove 11a of the feed adjustment slider crank 11. That is, the rotation of the transmission shaft 27 causes the feed adjustment slider 33 to slide up and down via the longitudinal feed adjustment crank 30. Therefore, the shaft portion 30a of the longitudinal feed adjustment crank 30 moves up and down within the groove portion 11a from a position that approximately coincides with the center of the main feed base support pin 6 to a position that approximately coincides with the crankshaft 11b of the feed adjustment slider crank 11. It is designed to slide.

On the other hand, the transmission shaft 27 has one end supported by the frame body 8, and the other end supported by the shaft support plate 3 fixed to the frame body 8 by screws 34.
5 is rotatably supported. The transmission shaft 27
An operating lever 37 is fixed to one side of the shaft support plate 35 with a screw 36. That is, the transmission shaft 27 rotates as the operating lever 37 rotates, and the feed adjustment slider 33 slides up and down in accordance with the rotation angle of the transmission shaft 37. Further, on the other side of the shaft support plate 35, a knock pin 3 is provided.
The adjusting block 39 is secured by 8.
By sandwiching the shaft support plate 35 between the adjustment block 39 and the operating lever 37, the transmission shaft 27 is restrained from moving in the axial direction.

Operation lever 37 screwed to the transmission shaft 27
A mounting hole 37a is bored in the free end of the holder to allow an operating rod (not shown) connected to a foot pedal, an air cylinder, a solenoid (not shown), or the like to be mounted. Further, a bulging portion formed by bulging the upper end surface of the operating lever 37 is formed near the mounting hole 37a, and a hole 37b is bored in this bulging portion. A tension coil spring 40 is attached to a pin 41 fixed to the frame body 8 in this hole 37b.

Further, a protrusion 37d having a substantially elliptical elongated hole 37c is formed in the center of the operating lever 37, and a stop pin 42 fixed to the frame body 8 is inserted into the elongated hole 37c. That is, the rotation angle of the operating lever 37 is regulated by the length of the elongated hole 37c. Therefore, the length of the elongated hole 37c is set so that the feed adjustment slider 33 can slide in the groove 11a of the feed adjustment slider crank 11 from the upper end to the lower end by rotating the operating lever 37.

The adjustment block 39, whose both sides are formed of thick plates having an elliptical shape in plan, has adjustment screws 43 and 46 fitted with coil springs 45 and 46 to prevent loosening on both sides.
44 is threaded through. This adjustment screw 43・
A stop plate 47 is fixed to the frame body 8 at the tip of each screw 44 so as to abut the respective screw ends.

Next, the operation of the cloth feeding device of this embodiment will be explained.

First, when the upper shaft 1 is rotated, the cloth feed table 4 swings about the crankshaft 11b of the adjustment slider crank 11 via the eccentric cranks 2 and 3.

In this case, in the normal cloth feeding state, that is, in the state in which the operating lever 37 is not operated, as shown in FIGS. The shaft portion 30a of the feed adjustment crank 30 is located at a position that substantially coincides with the center of the main feed base support pin 6. Therefore, the shaft portion 30a is connected to the crankshaft 11b.
A swinging motion with the same amplitude as the main feed support rod 5 is performed using the main feed support rod 5 as a fulcrum. Since the sub-feed table support rod 18 also performs the oscillating movement in response to the oscillating movement of the shaft portion 30a, the sub-feed table 15 attached to the main feed table 4 is integrated with the main feed table 4. Performs an oscillating motion to feed the cloth. That is, as shown in FIG. 8, the feed dog 24 attached to the sub-feed table 15
draws a circulation trajectory A indicated by a broken line. The stroke S and height H of this circulation locus A are determined by the amount of eccentricity of the eccentric cranks 2 and 3. Note that when the eccentricity of the eccentric cranks 2 and 3 is assumed to be constant and unchanging, the stroke S is at its maximum in the normal cloth feeding state when the operating lever 37 is not operated.

Next, the operating lever 37 is raised in the direction of arrow 0 shown in FIG. (Figure 9). Then, the shaft portion 30
a performs a rocking motion with an amplitude of approximately 1/2 using the crankshaft 11b as a fulcrum. Since this rocking motion of the shaft portion 30a is transmitted to the sub-feed base support rod 18, the height H of the circulation locus A of the feed dog 24 hardly changes as shown in No. 10, but the stroke S' is approximately Changes to 1/2. However, it is assumed that the eccentricity of the eccentric cranks 2 and 3 remains unchanged.

Furthermore, when the operating lever 37 is raised and the shaft portion 30a of the longitudinal feed adjustment crank 30 is aligned with the crankshaft 11b of the feed adjustment slider crank 11 (Fig. 11), the shaft portion 30a becomes a fixed point and swings. do not. Therefore, the sub-feed support rod 18
As shown in Fig. 12, the height H of the circulation path A of the feed dog 24 hardly changes, but the stroke S'' becomes almost zero. In this state, the fabric hardly moves. It is stopped without being fed. Therefore, if you perform overlapping sewing in this state, the sewing thread will not easily come undone.

In addition, by adjusting the adjustment screws 43 and 44, the rotation range of the operation lever 37, that is, the rotation range of the transmission shaft 27, is regulated to adjust the feed stroke to a predetermined length S.
It can be adjusted steplessly from S'' to almost zero.
That is, if the cloth feed stroke is set in advance, the desired feed amount can be obtained simply by operating the operating lever 37, even at the beginning of sewing or the end of sewing of the step-stitched portion of the pocket. Therefore,
There is no need to stop the sewing machine and sew again by hand, or use a darts-king sewing machine to perform reinforcing sewing work. For example, FIG. 13 shows the sewing state of the pockets on the back side of the fabric sewn using the fabric feeding device of the above embodiment, and the stitching at the beginning and end of the stitching part is different from other parts. The stitches are finely stitched to ensure that the threads do not come undone.

Note that in order to return to the normal cloth feeding state, the force applied to the operating lever 37 may be released. That is, the tension coil spring 40 causes the operating lever 37 to rotate in the direction opposite to the arrow 0 shown in FIG. Then, as the operating lever 37 rotates, the longitudinal feed adjustment crank 3 is activated via the transmission shaft 27.
Since the shaft portion 30a of No. 0 returns to the center of the main feed base support pin 6, the feed dog 24 performs a normal cloth feeding movement.

As mentioned above, in the present invention, a sub-feed table equipped with feed teeth is attached to the main feed plate, and the sub-feed table that supports the sub-feed table is configured to feed cloth by changing the amplitude of the rocking motion of the support rod. The feed adjustment slider attached to the front and rear feed adjustment crank changes the stroke.
It is provided in a groove of the feed adjustment slider crank so that it can freely slide up and down as the transmission shaft rotates. Therefore, the cloth feed stroke can be adjusted steplessly from a predetermined amount to almost zero, and as a result, there is no need to stop the sewing machine and sew by hand in areas such as pocket stitching. There is no need to perform reinforcing sewing work using a sewing machine, which improves work efficiency and allows beautiful seams to be obtained. Furthermore, by adjusting the cloth feed stroke to zero, you can perform almost perfect tacking stitches without stopping the sewing machine.
It has the advantage of being able to reliably prevent the threads from fraying.

[Brief explanation of the drawing]

Figures 1 to 13 show one embodiment of the present invention. Figure 1 is a three-dimensional perspective view showing the cloth feeding device of the present invention, and Figure 2 shows the fabric feeding mechanism incorporated into a blind stitch sewing machine. Figure 3 is a front view of Figure 2, Figure 4 is a side view showing the main parts of the main feeder and sub-feeder, and Figure 5 is a partial cross-section taken along the - line in Figure 4. 6 is a partial cross-sectional view taken along the - line in FIG.
FIG. 2 is a circulation locus diagram showing the movement state of the feed dog, and FIG. 13 is a reference diagram showing the sewing state according to the present invention. 1... Upper shaft, 2... Eccentric crank, 3... Eccentric crank, 4... Main feed stand, 5... Main feed stand support rod, 11... Feed adjustment slider crank, 1
1b...Crankshaft, 17...Support rod pin,
18... Sub-feed stand support rod, 24... Feed dog,
27...Transmission shaft, 30...Back and forth feed adjustment crank.

Claims (1)

[Scope of utility model registration request] The main feed bar 4 has its base end fitted into the eccentric cranks 2 and 3 of the upper shaft 1, and its intermediate part connected to the main feed bar support rod 5 which rotates around the crankshaft 11b of the feed adjustment slider crank 11. A support rod pin 17 attached to the main feed base 4 is attached to the main feed base 4 at a position approximately midway between the support position by the main feed base support rod 5 and the root end. A sub-feed base support rod 18 is rotatably provided, and this sub-feed base support rod 18
The base of a sub-feed table 15 is rotatably attached to the main feed plate 4 and has a feed dog 24 for feeding the cloth back and forth, and the tip of the sub-feed plate 15 is locked to the main feed plate 4 so as to be slidable back and forth. A longitudinal feed adjustment arm 28 is fixed to a transmission shaft 27 rotatably supported by the transmission shaft 27, and a sub-feed support rod 18 that moves up and down as the transmission shaft 27 rotates. A longitudinal feed adjustment crank 30 that changes the cloth feeding stroke of the sub-feed table 15 by changing the amplitude of the swinging motion of the
is provided with one end rotatably attached,
At the other end of the longitudinal feed adjustment crank 30, there is a feed adjustment slider 33 that is slid up and down in the groove 11a of the feed adjustment slider crank 11 by the vertical movement of the longitudinal feed adjustment crank 30, and a sub-feed support. A cloth feeding device for a sewing machine, characterized in that a sub-feed transmission rod 21 is rotatably attached to a rod 18.