Feeding device for covering chain stitch sewing machine

Abstract

To provide a feeding device for covering chain stitch sewing machine which solves the problem in which, compared with conventional ones, a load of manufacturing cost is large, and the change of a main feeding motion amount and a differential feeding motion amount requires extreme number of adjustment man-hours.SOLUTION: A main feeding amount adjustment cam 61 of a feeding amount adjustment mechanism 6 is pressed by a main feeding amount adjustment crank 63 fixed to a main feeding frontward / backward adjustment crank 45 and comes into slide contact, and a differential feeding amount adjustment cam 62 is pressed by a differential feeding amount adjustment crank 64 interlocked with a differential feeding frontward / backward adjustment crank 55 and comes into slide contact. A feeding amount adjustment cam shaft 60 is arranged in a rotatable manner, the main feeding amount adjustment cam 61 is inserted in the feeding amount adjustment cam shaft 60 and fixed, and the differential feeding amount adjustment cam 62 is inserted in the feeding amount adjustment cam shaft 60 and fixed. Thereby, by the rotation of the feeding amount adjustment cam shaft 60, the main feeding amount adjustment cam 61 and the differential feeding amount adjustment cam 62 rotate being interlocked.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a feed device for an interlock stitch sewing machine. In the present invention, "front and rear" refers to the front and rear direction in the fabric feed direction, "left and right" refers to the left and right direction when the sewing machine is viewed from the front, and "up and down" refers to the up and down direction of the sewing machine. [Background technology]

[0002] A known feed device for a conventional interlock stitch sewing machine is configured to include a fabric feed mechanism having a main feed dog, a differential feed dog, a main feed table, and a differential feed table, a manual operation unit that adjusts the main feed momentum (also called the main feed amount), which is the amount of movement of the main feed table in the front-to-back direction, and a manual operation unit that adjusts the differential feed momentum (also called the differential feed amount), which is the amount of movement of the differential feed table in the front-to-back direction (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4078049 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional technology, the manual operation unit that adjusts the main feed momentum and the manual operation unit that adjusts the differential feed momentum each consist of multiple mechanical elements including a link mechanism, which increases manufacturing costs.

[0005] Furthermore, when the sewing specifications change and the sewing machine's main feed momentum and differential feed momentum need to be adjusted, the amount of forward and backward movement of the main feed dog, which forms the basis of the stitch pitch, is changed using the manual operation unit that adjusts the main feed momentum. Then, the amount of forward and backward movement of the differential feed dog, which corresponds to the stretch of the fabric, is changed using the manual operation unit that adjusts the differential feed momentum. In sewing specifications, stitch pitch is often measured in 1mm or 0.5mm increments. For example, to change the stitch pitch from 2mm to 3mm, first operate the manual operation unit that adjusts the main feed momentum. The main feed momentum changes continuously, not in discrete increments, and the actual change is measured and the operation is repeated until the desired amount is reached. For example, the desired amount can be achieved through multiple steps, such as from 2mm to 3.5mm, 2.7mm, and 3.1mm.

[0006] Next, the manual operation unit that adjusts the differential feed momentum is operated. There are various reasons for adjusting the differential feed momentum, but when adjusting to suppress fabric stretch, first, a rough adjustment is made so that the main feed momentum and differential feed momentum are close to each other. Then, actual sewing is performed, and the stretch state of the fabric after sewing is checked and adjustment is made again. By repeating this process, the desired stretch state of the fabric can be obtained. In this way, changing the main feed momentum and differential feed momentum is a repetitive task, and it takes a lot of man-hours for adjustment.

[0007] An object of the present invention is to provide a feed device for an interlock stitch sewing machine that solves the problems of the high manufacturing cost and the time and effort required to change the main feed momentum and the differential feed momentum. [Means for solving the problem]

[0008] In order to achieve the above object, the invention described in claim 1 is a feed device for an interlock stitch sewing machine, which is equipped with a needle that moves back and forth up and down, a looper that moves back and forth left and right in conjunction with the needle, a throat plate that is installed on the sewing machine body and supports the fabric from below, and a presser foot that supports the fabric from above, characterized in that the feed device is equipped with a fabric feed mechanism that includes a main feed dog, a differential feed dog, a main feed table, a differential feed table, a feed up and down mechanism, a main feed front and back mechanism, and a differential feed front and back mechanism, and a feed amount adjustment mechanism that includes a main feed amount adjustment cam and a differential feed amount adjustment cam.

[0009] In order to achieve the above object, the invention described in claim 2 is the feed device for the interlock stitch sewing machine described in claim 1, characterized in that the feed amount adjustment mechanism includes a feed amount adjustment cam shaft that rotates the main feed amount adjustment cam and the differential feed amount adjustment cam in synchronization.

[0010] In order to achieve the above object, the invention described in claim 3 is the feed device for the interlock stitch sewing machine described in claim 2, characterized in that the main feed amount adjusting cam has a plurality of constant regions in its profile in which the main feed momentum does not change, and the differential feed amount adjusting cam has a plurality of variable regions in its profile in which the differential feed momentum changes in synchronization with each of the plurality of constant regions.

[0011] In order to achieve the above object, the invention described in claim 4 is a feed device for a flat stitch sewing machine described in claim 2, characterized in that it includes a motor that drives the feed amount adjusting cam shaft.

[0012] In order to achieve the above object, the invention described in claim 5 is a feed device for a flat stitch sewing machine described in claim 3, characterized in that it includes a motor that drives the feed amount adjusting cam shaft.

[0013] In order to achieve the above object, the invention described in claim 6 is a feed device for a flat stitch sewing machine described in claim 3, characterized in that it is provided with a knob with a mark that is linked to the feed amount adjustment cam shaft.

[0014] In order to achieve the above object, the invention described in claim 7 is a feed device for a flat stitch sewing machine described in any one of claims 1 to 6, characterized in that the main feed forward / backward mechanism comprises a main feed forward / backward source eccentric, a main feed forward / backward source rod, a main feed forward / backward source link, a main feed forward / backward shaft crank, a main feed forward / backward adjustment link, and a main feed forward / backward adjustment crank, and the main feed forward / backward adjustment crank is driven by the main feed amount adjustment cam.

[0015] In order to achieve the above object, the invention described in claim 8 is a feed device for a flat stitch sewing machine described in claim 7, characterized in that the differential feed forward / backward mechanism comprises a differential feed forward / backward source crank, a differential feed forward / backward source link, a differential feed forward / backward slide piece, a differential feed forward / backward shaft crank, a differential feed forward / backward adjustment link, and a differential feed forward / backward adjustment crank, and the differential feed forward / backward adjustment crank is driven by the differential feed amount adjustment cam. [Effects of the Invention]

[0016] According to the presser foot device of the present invention, by eliminating the multiple mechanical elements including the link mechanism of the prior art and providing a feed rate adjusting mechanism including a main feed rate adjusting cam and a differential feed rate adjusting cam, the device is simplified and the burden on manufacturing costs can be reduced. Furthermore, by providing the feed rate adjusting mechanism with a feed rate adjusting cam shaft that rotates the main feed rate adjusting cam and the differential feed rate adjusting cam in sync, changing the main feed momentum and differential feed momentum can be simplified and the number of adjustment steps can be reduced. [Brief explanation of the drawings]

[0017] [Figure 1] 1A and 1B are perspective views from the left front of a sewing machine applicable to the present invention and a perspective view from the left front showing an internal mechanism, in which the positive direction of the X axis indicates the right direction, the positive direction of the Y axis indicates the rearward direction, and the positive direction of the Z axis indicates the upward direction. [Figure 2] 1 is a perspective view of a fabric feeding mechanism of a feeding device of a sewing machine applied to the present invention, viewed from the left front. [Figure 3] 1 is a perspective view of a feed up / down mechanism of a feed device of a sewing machine applied to the present invention, seen from the left front. [Figure 4] 3A and 3B are a perspective view from the left front and a left side view of a main feed forward / backward mechanism of a feed device of a sewing machine that is applied to the present invention; [Figure 5] 3A and 3B are a perspective view from the left front and a left side view of a differential feed front-rear mechanism of a feed device of a sewing machine that is applied to the present invention. [Figure 6] 1 is a diagram showing a main feed forward / backward mechanism of a feed device of a sewing machine applied to the present invention, as viewed from the left side; [Figure 7] 1 is a diagram showing a differential feed front-rear mechanism of a feed device of a sewing machine applied to the present invention, as viewed from the left side. [Figure 8] 1 is a perspective view of a feed amount adjustment mechanism of a feed device of a sewing machine applied to the present invention, viewed from the left front. [Figure 9] 3A and 3B are front and bottom views of a feed amount adjustment mechanism of a feed device of a sewing machine that is applied to the present invention. [Figure 10] 1 is a left side view of a feed amount adjusting mechanism of a feed device of a sewing machine that is applied to the present invention. [Figure 11] 1 is a cross-sectional view of a feed amount adjusting mechanism of a feed device of a sewing machine applied to the present invention, seen from the left side. [Figure 12] 3A and 3B are diagrams showing a main feed amount adjusting cam and a differential feed amount adjusting cam of a feed device of a sewing machine applied to the present invention, and a schematic diagram of their operation. [Figure 13] 10A and 10B are perspective views of another embodiment of a feeding device of a sewing machine applied to the present invention, seen from the front left, and a detailed view of a portion of the feeding device seen from above at the front; [Figure 14] 10 is a perspective view of another embodiment of a feeding device of a sewing machine applied to the present invention, viewed from the left front. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] An example of an embodiment of the present invention will be described below with reference to FIGS. 1 to 12. FIG. 1 is a perspective view from the left front of a sewing machine applicable to the present invention, and a perspective view from the left front showing the internal mechanism. The positive direction of the X-axis indicates the rightward direction, the positive direction of the Y-axis indicates the rearward direction, and the positive direction of the Z-axis indicates the upward direction. Sewing machine 1 includes a needle 14 that moves up and down, a needle plate 15 installed in sewing machine body 10, and a looper 16 that moves back and forth from side to side, sandwiching needle 14 below needle plate 15, all of which work together to perform sewing. Presser foot 17 is movable up and down and is positioned on top of needle plate 15 while being pressed from above, sandwiching and pressing from above to grip the fabric being sewn. Upper shaft 11 and lower shaft 12 are rotatably arranged on sewing machine body 10 with their axial directions aligned left and right. They are connected to each other by a timing belt 13 on the right side. When lower shaft 12 is rotated by a drive device or the like, upper shaft 11 rotates in conjunction with it. The rotation of the upper shaft 11 is transmitted through various mechanical elements to become the driving force for the up and down movement of the needle 14 on the left. The rotation of the lower shaft 12 is also transmitted through various mechanical elements to become the driving force for the left and right reciprocating movement of the looper 16 on the left and the movement of the fabric feed mechanism 3 of the feed device 2. The feed device 2 has both the fabric feed mechanism 3 and the feed amount adjustment mechanism 6, of which the fabric feed mechanism 3 generates the movement necessary for fabric feed between the needle 14 and the looper 16 using the feed up and down mechanism 30, the main feed front and back mechanism 4, and the differential feed front and back mechanism 5.

[0019] Figure 2 is a perspective view, from the left front, of the fabric feed mechanism of the sewing machine feed device applicable to the present invention. The fabric feed mechanism 3 feeds the fabric as needed during sewing using the main feed table 22 and differential feed table 23, which are connected to the aforementioned feed up / down mechanism 30, main feed front / rear mechanism 4, and differential feed front / rear mechanism 5, and the main feed dog 20 and differential feed dog 21 fixed to one end of each. Fabric feed is performed by moving the fabric rearward by the distance of the stitch pitch each time the needle 14 and looper 16 form a stitch. This occurs when the needle 14 leaves the fabric on the upper surface of the throat plate 15 and moves upward. The rear main feed dog 20 and the front differential feed dog 21 rise from below the groove in the throat plate 15 to the upper surface, supporting the fabric from below and pressing it with the underside of the presser foot 17 as they move from front to rear. When needle 14 descends again to pierce the fabric, main feed dog 20 and differential feed dog 21 have already retreated below throat plate 15, and sewing is performed with the fabric being held by the underside of presser foot 17 and the upper surface of throat plate 15. Therefore, main feed dog 20 and differential feed dog 21 perform cyclical motion that combines up-and-down movement and back-and-forth movement, and main feed base 22 and differential feed base 23, which fix them in place, perform motion that describes an ellipse when viewed from the side.

[0020] 3 is a perspective view from the left front of the feed up / down mechanism of the sewing machine feed device that is applicable to the present invention. The feed up / down mechanism 30 controls the up / down movement of the main feed bar 22 and the differential feed bar 23. The main feed bar 22 and the differential feed bar 23 are plate-shaped and are arranged so that they can slide face-to-face, with the main feed bar 22 on the right side and the differential feed bar 23 on the left side. The main feed bar 22 and the differential feed bar 23 have U-shaped bifurcated sections at the rear and front, and rectangular parallelepiped feed bar rear upper and lower corner pieces 31 and feed bar front upper and lower corner pieces 32 are arranged inside the bifurcated sections so that they can slide, guided by their upper and lower surfaces. The feed bar rear upper and lower corner pieces 31 and feed bar front upper and lower corner pieces 32 have holes formed in the centers in the left-right direction.

[0021] A feed bed rear vertical eccentric shaft portion 120 provided at the left end of the lower shaft 12 is inserted from the right side into a hole in the feed bed rear vertical square piece 31, and as the lower shaft 12 rotates, the feed bed rear vertical square piece 31 moves up and down and back and forth, and the main feed bed 22 and differential feed bed 23, whose upper and lower surfaces are guided, move up and down accordingly. A feed bed front vertical eccentric 121 is fixed to the middle part of the lower shaft 12 on the right side of the main feed bed 22, and one end of a feed bed front vertical rod 33 is inserted in a swingable manner. One end of a feed bed front vertical shaft crank 34 is swingably connected to the other end of the feed bed front vertical rod 33, and the other end of the feed bed front vertical shaft crank 34 is fixed to a feed bed front vertical shaft 35 arranged on the sewing machine body 10 so as to be swingable left and right with its axial direction. A feed bed front vertical crank 36 is fixed to the left end of the feed bed front vertical shaft 35, and a pin 37 is installed at one end of the feed bed front vertical crank 36, and the pin 37 is inserted into a hole in the feed bed front vertical square piece 32 from the right side. Therefore, when the lower shaft 12 rotates, the feed bed front vertical shaft 35 swings due to the feed bed front vertical eccentric 121, the feed bed front vertical rod 33, and the feed bed front vertical shaft crank 34. Furthermore, when the feed bed front vertical crank 36 and pin 37 swing, the feed bed front vertical square piece 32 moves up and down, and the main feed bed 22 and differential feed bed 23 move up and down accordingly.

[0022] The feed bar rear upper and lower square pieces 31 and the feed bar front upper and lower square pieces 32 cannot be perfectly synchronized because the rear moves up and down due to an eccentric and the front moves up and down due to a crank swing. However, by approximately matching their vertical movements at the timing required for fabric feeding, the main feed bar 22 and the differential feed bar 23 are moved up and down as a whole. As mentioned above, fabric feeding occurs when the main feed dog 20 and the differential feed dog 21 are positioned above the top surface of the needle plate 15. In normal sewing, the main feed bar 22 and the differential feed bar 23 are adjusted to approximately match their vertical movements at this timing, so that the main feed dog 20 and the differential feed dog 21 are positioned nearly horizontally to feed the fabric. If the front is adjusted to rise first, the front side of the front differential feed dog 21 rises above the top surface of the needle plate 15 first, with the rear side following a little later. In this state, the main feed dog 20 and the differential feed dog 21 are inclined, with the front side up and the rear side down, which is generally referred to as the feed dog front-up position. The opposite state is referred to as the feed dog front-down position.

[0023] 4 is a perspective view from the left front and a left side view of the main feed front / rear mechanism of the sewing machine feed device that is applicable to the present invention. The main feed front / rear mechanism 4 causes the front / rear movement of the main feed table 22. A main feed front / rear source eccentric 40 is fixed to the middle of the lower shaft 12 on the right side of the main feed table 22, and one end of a main feed front / rear source rod 41 is swingably inserted therethrough. One end of a main feed front / rear source link 42 is swingably connected to the other end of the main feed front / rear source link 42, and one end of a main feed front / rear shaft crank 43 is swingably connected to the other end of the main feed front / rear shaft crank 43, and the other end of the main feed front / rear shaft crank 43 is fixed to the middle of a main feed front / rear shaft 47 that is arranged on the sewing machine body 10 so as to be swingable left and right with its axial direction. A main feed front-rear crank 48 is fixed to the left end of the main feed front-rear shaft 47, and one end of the main feed front-rear crank 48 is swingably connected to one end of a main feed table front-rear link 49, and the other end of the main feed table front-rear link 49 is inserted into a pin 220 installed on the left side of the main feed table 22.

[0024] Furthermore, one end of a main feed longitudinal adjustment link 44 is further swingably connected to the connecting portion of the main feed longitudinal source rod 41 and the main feed longitudinal source link 42. The main feed longitudinal adjustment crank 45 is an L-shaped bell crank, and its swing center is fixed to a main feed longitudinal adjustment crank shaft 46 that is arranged on the sewing machine body 10 so as to be swingable with its axial direction in the left-right direction, and another end of the main feed longitudinal adjustment link 44 is swingably connected to the tip of a connecting leg 451 that is an L-shaped single leg. Then, by fixing a support leg 450 that is another L-shaped single leg at a specific position, the position of the other end of the main feed longitudinal adjustment link 44 is determined by the tip of the connecting leg 451 of the main feed longitudinal adjustment crank 45.

[0025] In this state, when the lower shaft 12 rotates, the main feed longitudinal source eccentric 40 rotates, the main feed longitudinal source rod 41 moves while its movement is restricted by the main feed longitudinal adjustment link 44, the main feed longitudinal source link 42, whose movement is also restricted, moves, the main feed longitudinal shaft crank 43 swings, and the main feed longitudinal shaft 47 swings. Then, the main feed longitudinal crank 48 swings, the main feed base longitudinal link 49 moves back and forth, and the main feed base 22 moves back and forth via the pin 220.

[0026] The main feed momentum represents the amount of forward and backward movement of the main feed table 22. However, as described above, the main feed table 22 performs cyclical movement that combines up-down and back-and-forth movement while changing its inclination state during a single fabric feed operation, due to the feed up-down mechanism 30 and the main feed back-and-forth mechanism 4, making it difficult to accurately define the amount of main feed momentum. Therefore, the term main feed momentum is often conventionally referred to as the distance that the working end of the main feed back-and-forth crank 48, i.e., the connection portion with the main feed table back-and-forth link 49, moves forward and backward as a result of the swinging of the main feed back-and-forth crank 48. This is also the meaning used in the present invention. As described above, by approximately synchronizing the up-and-down movement of the main feed table 22 with the timing required for fabric feeding, and further by moving the main feed table back-and-forth link 49 in a nearly horizontal position to swing the main feed back-and-forth crank 48 within an acute angle range in the vertical direction, the distance that the working end moves forward and backward as a result of the swinging of the main feed back-and-forth crank 48 and the actual amount of forward and backward movement of the main feed table 22 become close enough to a value that does not cause any problems in terms of sewing specifications.

[0027] FIG. 5 shows a perspective view from the left front and a left side view of the differential feed mechanism of the sewing machine feed device applicable to the present invention. The differential feed mechanism 5 controls the forward and backward movement of the differential feed table 23. A differential feed source crank 50 is fixed to the right of the main feed shaft 47 to which the main feed shaft crank 43 is fixed. As a result, when the main feed shaft crank 43 swings, the differential feed source crank 50 swings via the main feed shaft 47. A differential feed source link 51 is swingably connected to one end of the differential feed source crank 50, and the other end of the differential feed source link 51 is inserted into a left-side pin 520 provided on a differential feed slide top 52. The differential feed slide top 52 has a groove extending vertically through its center, with the front and rear sides of the groove serving as arc-shaped sliding guide surfaces. A differential feed shaft 57 is arranged on the sewing machine body 10 so as to be swingable with its axial direction in the left-right direction, and the differential feed shaft crank 53 is fixed to the right side. The differential feed longitudinal shaft crank 53 is provided with a branch-like, arc-shaped sliding guide surface, and the above-mentioned differential feed longitudinal slide top 52 is slidably inserted through it with the corresponding sliding guide surface in face-to-face contact. A differential feed longitudinal crank 58 is fixed to the left end of the differential feed longitudinal shaft 57, and one end of the differential feed longitudinal crank 58 is swingably connected to one end of a differential feed base longitudinal link 59, the other end of which is inserted through a pin 230 installed on the left side of the differential feed base 23.

[0028] One end of the differential feed longitudinal adjustment link 54 is inserted into the right-side pin 521 provided on the differential feed longitudinal slide piece 52, and the other end of the differential feed longitudinal adjustment link 54 is swingably connected to one end of the differential feed longitudinal adjustment crank 55. Another end of the differential feed longitudinal adjustment crank 55 is provided with a shaft portion 550, which is swingably inserted into a bushing 56 provided on the sewing machine body 10. Then, by fixing the differential feed longitudinal adjustment crank 55 at a specific position, the position of the other end of the differential feed longitudinal adjustment link 54 is determined by the one end of the differential feed longitudinal adjustment crank 55 to which it is connected.

[0029] If the lower shaft 12 rotates in this state, as described above, the main feed longitudinal shaft crank 43 swings, the main feed longitudinal shaft 47 swings, the differential feed longitudinal source crank 50 swings, the differential feed longitudinal source link 51 moves while its movement is restricted by the differential feed longitudinal adjustment link 54 via the differential feed longitudinal slide top 52, the differential feed longitudinal shaft crank 53 swings while sliding on the differential feed longitudinal slide top 52, and the differential feed longitudinal shaft 57 swings. Then, the differential feed longitudinal crank 58 swings, the differential feed base longitudinal link 59 moves back and forth, and the differential feed base 23 moves back and forth via the pin 230.

[0030] The differential feed momentum represents the amount of movement of the differential feed table 23 in the front-to-rear direction, but like the main feed momentum, it is often conventionally referred to as the distance that the working end, i.e., the connecting portion with the differential feed table front-to-rear link 59, moves forward or backward due to the swinging of the differential feed front-to-rear crank 58, and is also used in this sense in the present invention. As described above, by approximately matching the up and down movement of the differential feed table 23 at the timing required for fabric feeding, and further by moving the differential feed table front-to-rear link 59 in a nearly horizontal state and swinging the differential feed front-to-rear crank 58 within an acute angle range in the vertical direction, the distance that the working end moves forward or backward due to the swinging of the differential feed front-to-rear crank 58 and the actual amount of movement of the differential feed table 23 in the front-to-rear direction become close to values ​​that do not cause any problems in terms of sewing specifications.

[0031] As described above, in this embodiment, the differential feed front-rear source crank 50 is fixed to the right of the main feed front-rear shaft 47 to which the main feed front-rear shaft crank 43 is fixed, so that when the main feed front-rear shaft crank 43 swings, the differential feed front-rear source crank 50 swings via the main feed front-rear shaft 47. In this configuration, the main feed front-rear shaft crank 43 is used as the driving force for swinging, and the differential feed front-rear source crank 50 swings in conjunction with it, but other configurations may be used. For example, an eccentric other than the main feed front-rear source eccentric 40 may be fixed to the lower shaft 12, and other rods, cranks, and shafts may be similarly arranged and connected to form a link mechanism, which may be used as the driving force for swinging, causing the differential feed front-rear source crank 50 to swing in conjunction with it.

[0032] FIG. 6 is a diagram showing the main feed forward / backward mechanism of a sewing machine feed device according to the present invention, viewed from the left side. The diagram is drawn in a manner similar to that used in general mechanism design. The crosshairs in the diagram represent the center of motion, the straight lines represent nodes at various positions of the mechanical elements, and their lengths represent pitches. The curves, including circles and arcs, represent the loci of motion of the pairs of the nodes. The arrowed lines are intended to draw attention to the main feed forward / backward mechanism 4. The main feed forward / backward momentum is changed as follows: The rotation of the main feed forward / backward source eccentric 40 causes the main feed forward / backward source rod 41 to reciprocate in the lower right direction as viewed in the figure. This movement is regulated by the main feed forward / backward adjusting link 44, and the connection between the main feed forward / backward source rod 41 and the main feed forward / backward adjusting link 44 reciprocates along an arc locus 440 centered on the connection between the main feed forward / backward adjusting link 44 and the connecting leg 451 of the main feed forward / backward adjusting crank 45. The main feed longitudinal source link 42 is also connected to this connecting portion, and the main feed longitudinal shaft crank 43 connected to the main feed longitudinal source link 42 is restricted to swing about the main feed longitudinal shaft 47. When the support leg 450 of the main feed longitudinal adjustment crank 45 is rotated about the main feed longitudinal adjustment crank shaft 46, the connecting leg 451 rotates, and the position of the connecting portion between the main feed longitudinal adjustment link 44 and the connecting leg 451 of the main feed longitudinal adjustment crank 45 changes. This changes the direction of reciprocating motion of the main feed longitudinal source rod 41, and the length and inclination of the chord of the arc trajectory 440 change.

[0033] The left diagram in Figure 6 shows a case where the main feed momentum is large, and the right diagram shows a case where it is small. In the right diagram, compared to the left diagram, the support leg 450 rotates, and the end of the string on the upper side of the diagram moves as if pulling back the main feed front and rear shaft crank 43 from its farthest position, while the end of the string on the lower side of the diagram moves as if pushing the main feed front and rear shaft crank 43 away from its closest position. This reduces the amount of oscillation of the main feed front and rear shaft crank 48, thereby reducing the main feed momentum.

[0034] In FIG. 6 , the line indicating the main feed longitudinal adjustment link 44 and the line indicating the connecting leg 451 are the same length. As a result, the arcuate trajectory 440 intersects with the center of the main feed longitudinal adjustment crankshaft 46. When the main feed longitudinal source eccentric 40 rotates and the connecting portion between the main feed longitudinal source rod 41 and the main feed longitudinal adjustment link 44 is in this position, even if the support leg 450 rotates and the center of the arcuate trajectory 440 moves, the main feed longitudinal source rod 41, the main feed longitudinal source link 42, and the main feed longitudinal axis crank 43 do not move, and the main feed longitudinal crank 48 does not move either. In other words, even if the main feed momentum is adjusted in this state, the main feed dog 20 does not move. This is useful because it prevents the fabric from shifting when the sewing machine is stopped at this position, the main feed momentum is changed after the stop, and sewing is resumed. Note that the present invention is not limited to the above-described length being the same for the line indicating the main feed longitudinal adjustment link 44 and the line indicating the connecting leg 451, and they may be different lengths.

[0035] FIG. 7 is a left side view of the differential feed front-rear mechanism of the sewing machine feed device that is applicable to the present invention. In the differential feed front-rear mechanism 5, the differential feed momentum is changed as follows. The differential feed front-rear source crank 50 swings due to the swinging of the main feed front-rear shaft crank 43 and the main feed front-rear shaft 47. A differential feed front-rear source link 51 connected to the differential feed front-rear source crank 50 reciprocates the differential feed front-rear slide top 52, but the movement of the differential feed front-rear slide top 52 is restricted by a differential feed front-rear adjustment link 54. The differential feed front-rear adjustment link 54 is connected to a differential feed front-rear adjustment crank 55 and can swing around this connection. The differential feed front-rear shaft crank 53 swings while sliding on the differential feed front-rear slide top 52, swinging the differential feed front-rear shaft 57 and swinging the differential feed front-rear crank 58.

[0036] When the differential feed longitudinal adjustment crank 55 is rotated about the shaft 550, the differential feed longitudinal adjustment link 54 moves, which moves the differential feed longitudinal slide top 52, changing the distance between the differential feed longitudinal slide top 52 and the differential feed longitudinal shaft 57, which is the center of oscillation of the differential feed longitudinal shaft crank 53. As a result, the amount of oscillation of the differential feed longitudinal shaft crank 53, which is oscillated by the differential feed longitudinal source link 51 and the differential feed longitudinal slide top 52, changes, and the amount of oscillation of the differential feed longitudinal crank 58 changes.

[0037] The left diagram in Figure 7 shows a case where the differential feed momentum is small, and the right diagram shows a case where it is large. Compared to the left diagram, the amount of oscillation of the differential feed front / rear shaft crank 53 in the right diagram has increased as the differential feed front / rear adjustment crank 55 rotates, causing the differential feed front / rear slide piece 52 to move closer to the differential feed front / rear shaft 57. Therefore, the amount of oscillation of the differential feed front / rear crank 58 increases, and the differential feed momentum increases.

[0038] As described above, in this embodiment, the main feed momentum can be changed by rotating the main feed forward / backward adjusting crank 45, and the differential feed momentum can be changed by rotating the differential feed forward / backward adjusting crank 55. In this embodiment, the main feed forward / backward axis crank 43 is the driving force behind the oscillation, and the differential feed forward / backward source crank 50 oscillates in conjunction with it. Therefore, when the main feed momentum is changed, the differential feed momentum also changes. However, the ratio by which the differential feed momentum is scaled relative to the main feed momentum does not change. This ratio is generally referred to as the differential ratio. For example, if the main feed momentum is 1.0 mm and the differential ratio is set to 2.0, the differential feed momentum will be 2.0 mm. If the differential ratio is set to 0.7, the differential feed momentum will be 0.7 mm.

[0039] FIG. 8 is a perspective view, from the left front, of the feed amount adjustment mechanism of the sewing machine feed device that is applicable to the present invention. The feed amount adjustment mechanism 6 adjusts the main feed momentum and the differential feed momentum using a main feed amount adjustment cam 61 and a differential feed amount adjustment cam 62. The main feed amount adjustment cam 61 is a plate cam, and its outer periphery is pressed against and slides on a main feed amount adjustment crank 63 fixed to the main feed forward / backward adjustment crank 45. This pressing is performed by a first spring member 72. The differential feed amount adjustment crank 64 is inserted into a differential feed amount adjustment crankshaft 65 that is supported by a bearing installed in the sewing machine body 10. The differential feed amount adjustment cam 62 is a plate cam, and its outer periphery is pressed against and slides on the differential feed amount adjustment crank 64. This pressing is performed by a second spring member 73. The differential feed amount adjustment crank 64 is linked to the differential feed forward / backward adjustment crank 55 via a link mechanism, which will be described later.

[0040] The feed amount adjusting cam shaft 60 is disposed so as to be rotatable left and right in the axial direction by a left cam shaft bearing 70 and a right cam shaft bearing 71 mounted on the sewing machine body 10. The main feed amount adjusting cam 61 is inserted into and fixed to the left end of the feed amount adjusting cam shaft 60. The differential feed amount adjusting cam 62 is inserted into and fixed to the right end of the feed amount adjusting cam shaft 60. As a result, when the feed amount adjusting cam shaft 60 rotates, the main feed amount adjusting cam 61 and the differential feed amount adjusting cam 62 rotate synchronously. In this embodiment, a motor coupling 80 and a stepping motor 8 are connected to the right end of the feed amount adjusting cam shaft 60 and used as driving devices. The stepping motor 8 may be any other type of motor capable of high-precision position control, such as a servo motor.

[0041] 9 is a front view and a bottom view of the feed amount adjustment mechanism of the feed device of a sewing machine that is applicable to the present invention. As described above, the shaft portion 550 of the differential feed front-rear adjustment crank 55 is swingably inserted into the bushing 56. The bushing 56 has an inner hole therethrough, and the shaft portion 550 is longer than the bushing 56 and has a protruding shaft end, to which the differential feed amount adjustment auxiliary crank 67 is fixed. The differential feed amount adjustment link 66 is swingably connected to one end of the differential feed amount adjustment auxiliary crank 67. The other end of the differential feed amount adjustment link 66 is connected to one end of the differential feed amount adjustment crank 64 described above. Therefore, when the differential feed amount adjustment crank 64 swings about the differential feed amount adjustment crank shaft 65 described above, the differential feed amount adjustment link 66 is linked, and the differential feed amount adjustment auxiliary crank 67 and the differential feed front-rear adjustment crank 55 swing.

[0042] 10 is a left side view of the feed amount adjusting mechanism of the feed device of a sewing machine that is applied to the present invention. The above-mentioned first spring member 72 includes a bracket 720, a holder 721, a holder 722, and a first spring 723. Bracket 720 is fixed to sewing machine body 10, holder 721 is swingably mounted on bracket 720, and holder 722 is swingably mounted on main feed amount adjusting crank 63. First spring 723 is a compression coil spring, and both sides of first spring 723 are inserted into a shaft portion with seats provided on holders 721 and 722 to apply pressure.

[0043] The second spring member 73 described above includes a holder 730 and a second spring 731. The holder 730 is fixed to the camshaft right bearing 71. The second spring 731 is a tension coil spring, one end of which is supported by a protrusion on the holder 730 and the other end of which is supported by a protrusion provided in the middle of the differential feed amount adjusting crank 64, thereby pressing the differential feed amount adjusting crank 64. In addition, a torsion coil spring 732 may be inserted into a bushing 56 to press the differential feed forward / backward adjusting crank 55, thereby assisting the second spring member 73.

[0044] Figure 11 is a cross-sectional view, seen from the left side, of the feed amount adjustment mechanism of the feed device of a sewing machine that is applicable to the present invention. There are multiple cross-sectional views, and the symbols AA-AA, BB-BB, CC-CC, DD-DD, and EE-EE below the views indicate cross sections at the positions of the same symbols marked in the upper view of Figure 9. The cross section at symbol AA-AA is the position of the main feed forward / backward adjustment crank 45, and the main feed amount adjustment crank 63 is fixed to the support leg 450. The cross section at symbol BB-BB is the position of the main feed amount adjustment crank 63, and the circumferential sliding portion 630 provided on the main feed amount adjustment crank 63 is pressed against and slides against the outer periphery of the main feed amount adjustment cam 61.

[0045] The cross section marked CC-CC is a position where the differential feed longitudinal adjustment crank 55 is viewed from the left, and the differential feed longitudinal adjustment crank 55 is linked to the differential feed amount adjustment crank 64 via the differential feed amount adjustment auxiliary crank 67 and the differential feed amount adjustment link 66, and the differential feed amount adjustment crank 64 is pressed against and slides against the outer periphery of the differential feed amount adjustment cam 62. The cross section marked DD-DD is a position where the differential feed longitudinal adjustment link 54 is viewed from the left, and one end of the differential feed longitudinal adjustment link 54 is inserted into the right-side pin 521 provided on the differential feed longitudinal slide piece 52, and the other end of the differential feed longitudinal adjustment link 54 is swingably connected to one end of the differential feed longitudinal adjustment crank 55. The cross section marked EE-EE is the position of the differential feed amount adjustment crank 64, and a circumferential sliding portion 640 provided on the differential feed amount adjustment crank 64 is pressed against and slides against the outer periphery of the differential feed amount adjustment cam 62.

[0046] 12 shows diagrams of the main feed amount adjusting cam and differential feed amount adjusting cam of the feed device of a sewing machine that is applicable to the present invention, as well as a schematic diagram of their operation. The upper left diagram shows the profile of the main feed amount adjusting cam 61 as viewed from the left (the contour shape of the outer periphery that determines the operation of the cam), and the upper right diagram shows the profile of the differential feed amount adjusting cam 62. The two diagrams on the lower left are schematic diagrams of the main feed amount adjusting cam 61 when it operates, and the two diagrams on the lower right are schematic diagrams of the differential feed amount adjusting cam 62 when it operates.

[0047] The main feed adjustment cam 61 has a profile extending leftward from the center of the figure, which maintains the same radius and moves a fixed distance. This profile is referred to as the fixed area FA1. A short distance from the fixed area FA1, there is a fixed area FA2 with a slightly larger radius than the fixed area FA1. Similarly, fixed areas FA3, FA4, ..., FA9 are provided with gradually increasing radii. Each fixed area FAX (where X is a number from 1 to 9) is an arc with its center at the center of rotation of the main feed adjustment cam 61. In this embodiment, starting with the fixed area FA1 on the left side of the cam, the fixed areas FAX are provided in order, discretely moving clockwise as viewed in the figure, with the final fixed area FA9 located below the cam. The profile between each fixed area FAX is provided as a curve with a smooth transition.

[0048] The differential feed adjustment cam 62 has a profile that moves upward from the center as viewed in the figure, with the radius expanding for a fixed distance; this is referred to here as variable region FB1. A short distance from variable region FB1 is variable region FB2, which similarly expands in radius as variable region FB1 and moves a fixed distance. Similarly, variable regions FB3, FB4, ..., FB9 are also provided. Note that the radius of each variable region FBX (where X is a number from 1 to 9) does not necessarily increase by the same amount. In this embodiment, starting with variable region FB1 at the top of the cam, each variable region FBX is provided in sequence, discretely moving clockwise as viewed in the figure, with the final variable region FB9 being provided on the left side of the cam. The profiles between each variable region FBX are provided with curves that provide a smooth transition.

[0049] The two left-hand diagrams at the bottom of Figure 12 are schematic diagrams of the main feed adjustment cam 61 in operation. In these two diagrams, the main feed adjustment cam 61 rotates within the range of the fixed area FA1. At this time, the sliding contact portion 630 of the main feed adjustment crank 63, which is in sliding contact with the main feed adjustment cam 61, does not move, and the support leg 450 of the main feed forward / backward adjustment crank 45, which fixes this, also does not move. For example, if the main feed momentum at this time is 0.5 mm, this will be maintained within the range of the fixed area FA1. If the main feed momentum for the fixed areas FA1, FA2, FA3, FA4, . . . , FA9 is set to 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, . . . , 4.5 mm in 0.5 mm increments, this will be maintained within each fixed area FAX.

[0050] In this embodiment, the constant areas FAX are arranged in numerical order. This allows the profile between each constant area FAX to transition at a gentle slope throughout, compared to a case where the profile radius changes from expanding to contracting along the way, such as in the order FA1, FA3, FA5, FA7, FA9, FA8, FA6, FA4, and FA2. As a result, when the main feed adjustment cam 61 operates, the sliding contact portion 630 of the main feed adjustment crank 63 moves less as it slides against the profile between each constant area FAX, reducing the pressure angle and the load applied to the sliding contact portion 630.

[0051] The two right-hand diagrams at the bottom of Figure 12 are schematic diagrams illustrating the operation of the differential feed adjustment cam 62. In these diagrams, the differential feed adjustment cam 62 rotates within the range of the fluctuation region FB1. At this time, unlike the sliding contact portion 630 described above, the sliding contact portion 640 of the differential feed adjustment crank 64, which slides against the differential feed adjustment cam 62, moves. This causes the differential feed front / rear adjustment crank 55 to move via the differential feed adjustment crank 64, differential feed adjustment link 66, and differential feed adjustment auxiliary crank 67, changing the differential feed momentum. For example, if this change occurs in the differential ratio range of 0.9 to 1.7, the differential feed ratio can be adjusted to the desired value by rotating the differential feed adjustment cam 62 within the range of the fluctuation region FB1.

[0052] The fixed areas FAX of the main feed amount adjustment cam 61 and the variable areas FBX of the differential feed amount adjustment cam 62 correspond to the same X number, and are set so that they synchronize when the main feed amount adjustment cam 61 and the differential feed amount adjustment cam 62 are rotated by the same rotation angle. In other words, when the main feed amount adjustment cam 61 and the differential feed amount adjustment cam 62 are rotated by the same rotation angle, the fixed area FA1 is within the variable area FB1, and similarly for the others. As a result, even if the main feed amount adjustment cam 61 is rotated within each fixed area FAX, the driven side of the main feed amount adjustment cam 61 does not move, but the driven side of the differential feed amount adjustment cam 62, which is within each variable area FBX, does move. In other words, even if the main feed amount adjustment cam 61 and the differential feed amount adjustment cam 62 are rotated by the same rotation angle within the ranges of the same numbers FAX and FBX, the main feed momentum does not change, and only the differential ratio changes.

[0053] In this embodiment, the main feed momentum and differential feed momentum of the sewing machine are adjusted as follows. The values ​​of the main feed momentum and differential feed ratio are the same as those in the example described above. For example, if the sewing specifications are fixed and the main feed momentum is changed from 1.0 mm to 2.0 mm and the differential feed ratio is changed from 1.2 to 1.0, the main feed amount adjusting cam 61 and the differential feed amount adjusting cam 62 are rotated from their positions where the differential feed ratio is 1.2 in the fixed region FA2 and variable region FB2 to their positions where the differential feed ratio is 1.0 in the fixed region FA4 and variable region FB4. Furthermore, if only the differential feed ratio is to be changed, the cams are rotated within the range of the fixed region FA4 and variable region FB4.

[0054] Another embodiment of the present invention will be described below with reference to FIG. 13. FIG. 13 is a perspective view from the front left of another embodiment of a sewing machine feed device applicable to the present invention, and a detailed view of a portion of the feed device from above from the front. In the above-described embodiment, the feed amount adjustment cam shaft 60, which synchronously rotates the main feed amount adjustment cam 61 and the differential feed amount adjustment cam 62 of the feed amount adjustment mechanism 6, is connected to the stepping motor 8 via the motor coupling 80 to drive the cam. However, instead, a marked knob 74 interlocking with the feed amount adjustment cam shaft 60 may be provided. In this embodiment, the marked knob 74 is provided on the right end of the feed amount adjustment cam shaft 60, which protrudes to the right of the cam shaft right bearing 71. Therefore, by turning the marked knob 74, the feed amount adjustment cam shaft 60 rotates, and the main feed amount adjustment cam 61 and the differential feed amount adjustment cam 62 rotate synchronously for adjustment. After adjustment, the marked knob 74 is fixed in position using a screw or the like.

[0055] The marked knob 74 is disk-shaped and has multiple number markings 740 spaced apart on its outer periphery. These markings indicate the amount of main feed momentum. In this embodiment, they are marked in 0.5-mm increments, such as 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, etc., and correspond to the constant regions FA1, FA2, FA3, FA4, etc. of the main feed rate adjustment cam 61. To the left of the number markings 740 is a triangular mark 741, which resembles a triangle with the apex at the top and the base at the bottom. To the left of the triangular mark 741, slightly above the center, is a line mark 742. A tray-shaped cover 75 with a match mark is installed to the right of the right camshaft bearing 71, and its outer periphery is positioned to cover the triangular mark 741 and line mark 742 of the marked knob 74 from the left. The tray-shaped cover 75 with a reference mark has a cutout on the outer periphery of its side, and when the marked knob 74 is turned to align the number mark 740 with the right side of the cutout, a triangular mark 741 and a line mark 742 become visible through the cutout. A reference mark 750 is marked on the left side of the cutout on the cover 75 with a reference mark.

[0056] In this embodiment, the main feed momentum and differential feed momentum of the sewing machine are adjusted as follows. First, find the number mark 740 that corresponds to the desired main feed momentum, and then rotate the marked knob 74 so that the line mark 742 to the left of the number mark 740 aligns with the reference mark 750. The triangle mark 741 to the right of the line mark 742 indicates the change in the differential feed momentum, with the differential feed momentum being small near the upper apex of the triangle and large near the lower base. When the line mark 742 and the reference mark 750 align, the differential feed ratio is 1.0, and the differential feed momentum is equal to the main feed momentum. Therefore, the above-described procedure, which required repeated operations in the prior art, completes the main feed momentum adjustment and the subsequent adjustment of the differential feed momentum to approximate the main feed momentum, greatly simplifying the process compared to the prior art. The rest of the process is the same as with conventional techniques, whereby the sewing is actually carried out, and while checking the condition of the sewn product, the marked knob 74 is rotated within the height range of the triangular mark 741 to repeatedly adjust the differential feed momentum, and the adjustment change is then completed.

[0057] In the above-described embodiment, a marked knob 74 is provided instead of the stepping motor 8 and is linked to the feed rate adjustment cam shaft 60. However, both the stepping motor 8 and the marked knob 74 may be provided and linked together. This allows adjustments to be made selectively using the stepping motor 8 and the marked knob 74 as needed. This is useful, for example, when all power to electrical equipment is turned off for maintenance purposes to perform inspection and adjustment. Also, in the above-described embodiment, the marked knob 74 is provided at the right end of the feed rate adjustment cam shaft 60. However, the marked knob 74 may instead be provided via a transmission element or another shaft that is linked to the feed rate adjustment cam shaft 60.

[0058] Another embodiment of the present invention will be described below with reference to FIG. 14. FIG. 14 is a perspective view from the left front of another embodiment of a sewing machine feed device to which the present invention is applied. In the above-described embodiment, the feed amount adjusting cam shaft 60, which synchronously rotates the main feed amount adjusting cam 61 and the differential feed amount adjusting cam 62 of the feed amount adjustment mechanism 6, is connected to and driven by the stepping motor 8 via the motor coupling 80. However, instead, it may be connected to the stepping motor 8 via a transmission element or another shaft that interlocks with the feed amount adjusting cam shaft 60. In this embodiment, a second driven gear 85 is provided on one end of the feed amount adjusting cam shaft 60. The stepping motor 8 is fixed to a motor bracket 81 provided on the sewing machine body 10, and a first main driving gear 82 is provided on the motor shaft. The drive adjusting shaft 68 is rotatably provided on the sewing machine body 10, and a first driven gear 83 and a second main driving gear 84 are provided on both ends thereof. These four gears are positioned such that the first main driving gear 82 and the first driven gear 83 mesh together to transmit power, and the second main driving gear 84 and the second driven gear 85 mesh together to transmit power. As a result, the rotation of the stepping motor 8 is transmitted to the feed amount adjusting cam shaft 60. The same effect can be obtained by using a timing belt or the like instead of transmission using these gears.

[0059] By driving the feed amount adjusting cam shaft 60 with the stepping motor 8, the main feed momentum and differential feed momentum can be adjusted electrically rather than mechanically, thereby saving labor. Electrical adjustment can be performed using a general method, for example, by connecting the motor to a control device and an operating device. The operating device can be a general device such as a touch panel with a display unit for the main feed momentum and differential feed momentum, and the motor can be operated via the control device by changing the numerical values. In addition, by providing a memory unit in the control device, it is possible to call up the appropriate values ​​for the main feed momentum, differential feed momentum, and differential ratio from the memory unit every time the sewing specifications are changed.

[0060] Furthermore, in machines equipped with a motor, the main feed momentum can be adjusted with minimal effort to prevent fraying. Fraying refers to the process of the entire stitch unraveling after a portion of the thread has come off the end of the stitch for some reason, and fray prevention is a process to prevent this. With an interlock stitch sewing machine, fraying can be prevented by stopping the sewing machine slightly before the end of the stitch, minimizing the main feed momentum, creating very fine stitches, and sewing several to a dozen times. For this purpose, a dedicated device including a drive mechanism and a switch is used. With the feed device of the present invention, as described above, the main feed momentum and differential feed momentum can be adjusted, and the main feed momentum can be minimized to prevent fraying, eliminating the need for a separate dedicated device.

[0061] According to the feed device of the interlock stitch sewing machine described above, by providing a feed amount adjustment mechanism including a main feed amount adjustment cam and a differential feed amount adjustment cam, it is possible to simplify and reduce the burden on manufacturing costs. Furthermore, by providing the feed amount adjustment mechanism with a feed amount adjustment cam shaft that rotates the main feed amount adjustment cam and the differential feed amount adjustment cam in synchronization, it is possible to simplify changing the main feed momentum and differential feed momentum, thereby reducing the number of adjustment steps.

[0062] The present invention is not limited to the above-described embodiment, and those skilled in the art can make various modifications to the above-described embodiment without departing from the spirit of the present invention, and the present invention also encompasses such modifications. Furthermore, although this embodiment uses a flat stitch sewing machine, the present invention is not limited to this, and can be implemented with other chain stitch sewing machines, such as a single-needle or multi-needle double chain stitch sewing machine equipped with a feed device similar to that of a flat stitch sewing machine. [Explanation of symbols]

[0063] 1 sewing machine 2 Feeder 3 Fabric feeding mechanism 4 Main feed forward / backward mechanism 5 Differential feed mechanism 6. Feed rate adjustment mechanism 8 Stepping Motor 10 Sewing machine body 11 Upper shaft 12 Lower axis 13 Timing belt 14 needles 15 Needle plate 16 Looper 17 Presser foot 20 Main feed dog 21 Differential feed dog 22 Main slide 23 Differential slide 30 Feed up / down mechanism 31 Feed table rear upper and lower corner pieces 32 Feed table front upper and lower corner pieces 33 Feed table front up / down rod 34 Feed table front vertical axis crank 35 Slide table front up / down axis 36 Feed table front up / down crank 37 pin 40 Main feed front and rear source eccentric 41 Main feed front and rear source rod 42 Main feed front and rear source link 43 Main feed front and rear shaft crank 44 Main feed front / rear adjustment link 45 Main feed front / rear adjustment crank 46 Main feed front / rear adjustment crankshaft 47 Main feed front and rear axis 48 Main feed front and rear crank 49 Main feed table front and rear link 50 Differential feed front and rear source crank 51 Differential feed front and rear source link 52 Differential feed front and rear slide piece 53 Differential feed front and rear shaft crank 54 Differential feed front and rear adjustment link 55 Differential feed front / rear adjustment crank 56 Bush 57 Differential feed front and rear shaft 58 Differential feed front and rear crank 59 Differential slide front and rear link 60 Feed rate adjustment cam shaft 61 Main feed rate adjustment cam 62 Differential feed rate adjustment cam 63 Main feed rate adjustment crank 64 Differential feed adjustment crank 65 Differential feed adjustment crankshaft 66 Differential feed adjustment link 67 Differential feed adjustment auxiliary crank 68 Drive adjustment shaft 70 Camshaft left bearing 71 Camshaft right bearing 72 First spring member 73 Second spring member 74 Knob with markings 75 Cover with matching mark 80 Motor Coupling 81 Motor bracket 82 First driving gear 83 First driven gear 84 Second main driving gear 85 Second driven gear 120 Feed base rear upper and lower eccentric shaft 121 Feed table front up / down eccentric 220 pins 230 pins 440 Arc Trajectory 450 Support leg 451 Connecting leg 520 left pin 521 Right Pin 550 Shaft 630 Sliding contact part 640 Sliding contact part 720 bracket 721 Holder 722 Holder 723 First Spring 730 Holder 731 Second Spring 732 Torsion coil spring 740 number stamp 741 triangle mark 742 Line mark 750 joint seal FA1~9 invariant region FB1~9 fluctuation area

Claims

1. A feed device for an interlock stitch machine is provided with a needle that reciprocates up and down, a looper that reciprocates left and right in conjunction with the needle, a throat plate that is attached to the sewing machine body and supports the fabric from below, and a presser foot that supports the fabric from above, characterized in that the feed device is provided with a fabric feed mechanism that includes a main feed dog, a differential feed dog, a main feed table, a differential feed table, a feed up and down mechanism, a main feed front and rear mechanism, and a differential feed front and rear mechanism, and a feed amount adjustment mechanism that includes a main feed amount adjustment cam and a differential feed amount adjustment cam.

2. 2. The feed device for a flat stitch sewing machine according to claim 1, wherein the feed amount adjustment mechanism includes a feed amount adjustment cam shaft that rotates the main feed amount adjustment cam and the differential feed amount adjustment cam in synchronization with each other.

3. 3. The feed device for a flat stitch sewing machine according to claim 2, wherein the main feed amount adjusting cam has a plurality of constant regions in its profile in which the main feed momentum does not change, and the differential feed amount adjusting cam has a plurality of variable regions in its profile in which the differential feed momentum changes in synchronization with the plurality of constant regions.

4. 3. The feed device for a flat stitch sewing machine according to claim 2, wherein the feed device includes a motor that drives the feed amount adjusting cam shaft.

5. 4. The feed device for a flat stitch sewing machine according to claim 3, wherein the feed device includes a motor that drives the feed amount adjusting cam shaft.

6. 4. The feed device for a flat stitch sewing machine according to claim 3, wherein the feed device includes a knob with a mark that moves in conjunction with the feed amount adjusting cam shaft.

7. 7. The feed device for a flat stitch sewing machine according to claim 1, wherein the main feed forward / backward mechanism comprises a main feed forward / backward source eccentric, a main feed forward / backward source rod, a main feed forward / backward source link, a main feed forward / backward shaft crank, a main feed forward / backward adjustment link, and a main feed forward / backward adjustment crank, and the main feed forward / backward adjustment crank is driven by the main feed amount adjustment cam.

8. 8. The feed device for a flat stitch sewing machine according to claim 7, wherein the differential feed forward / backward mechanism comprises a differential feed forward / backward source crank, a differential feed forward / backward source link, a differential feed forward / backward slide piece, a differential feed forward / backward shaft crank, a differential feed forward / backward adjustment link, and a differential feed forward / backward adjustment crank, and the differential feed forward / backward adjustment crank is driven by the differential feed amount adjustment cam.

Images