A sewing machine thickness adjusting device

Abstract

This invention provides a thickness adjustment device for a sewing machine, belonging to the field of sewing machine technology. It solves the problem of cumbersome adjustment in existing thickness adjustment mechanisms. The sewing machine includes a housing, a feed dog, and an eccentric shaft. One end of the eccentric shaft is connected to the feed dog. The adjustment mechanism includes an electromagnet, a mounting bracket, a linkage rod, a limit rod, an elastic element, a limit wheel fixed to the other end of the eccentric shaft, and a driver fixed to the housing. The electromagnet is fixed to the housing via the mounting bracket, which has several stop holes. A stop plate is fixed to the core of the electromagnet, and a stop pin is fixed to the stop plate. The top of the linkage rod is hinged to the stop plate, and the bottom is hinged to the limit rod. The limit wheel has a protruding limit part that abuts against the limit rod under the action of the elastic element. A circumferential positioning structure is provided between the core of the electromagnet and the output shaft of the driver. This thickness adjustment device for a sewing machine has the advantage of convenient adjustment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of sewing machines, and relates to a sewing machine thick-thin adjusting device. BACKGROUND

[0002] The feeding process of the overlock machine is mainly realized by the reciprocating elliptical motion of the feed dog frame. The overlock machine continuously lifts and pulls the fabric on the needle plate through the feed dog frame, so as to continuously drag the fabric to be processed to the machine head to complete the entire feeding process. The angle of the feed dog frame of the traditional overlock machine is fixed, and only fabrics of a specific thickness can be processed. When sewing thick fabrics, the fabric may be layered or the stitches may be too dense due to insufficient fabric dragging force of the feed dog frame. When sewing thin fabrics, the fabric may be wrinkled due to excessive feeding.

[0003] In view of the above problems, people have made various improvements, and some have even applied for patents. For example, the overlock machine feeding adjustment mechanism [application number: 201920911353.5; authorized announcement number: CN210314737U] is disclosed in Chinese patent literature. It includes a support, a feed dog frame mounted on the support, and an adjusting assembly connected to the feed dog frame. The adjusting assembly includes an eccentric shaft mounted on the support and a adjusting rod connected to the eccentric shaft. The eccentric shaft includes a concentric segment connected to the adjusting rod and an eccentric segment connected to the concentric segment. The eccentric segment is simultaneously provided in the first sliding groove and the second sliding groove. By swinging the adjusting rod, the eccentric segment produces a small swing when the concentric segment rotates. The eccentric segment can drive the main feed dog frame and the differential feed dog frame to produce deflection, thereby adjusting the relative height between the main tooth and the differential tooth, facilitating the adaptation of fabrics of different thicknesses.

[0004] The feeding adjustment mechanism of this structure is manually rotated to the high gear or the low gear, the feed dog frame is inclined, the height of the main tooth is lower or higher than that of the differential tooth, the feeding adjustment mechanism is adjusted, and then locked by the locking assembly. However, this feeding adjustment mechanism is adjusted manually, which is troublesome. SUMMARY

[0005] The purpose of the present application is to solve the above-mentioned problems in the prior art, and to provide a sewing machine thick-thin adjusting device. The technical problem to be solved is how to automatically adjust the adjusting mechanism and make the adjustment convenient.

[0006] The purpose of the present application can be achieved by the following technical solutions: a sewing machine thickness adjusting device, the sewing machine comprising a housing, a feed dog frame and an eccentric shaft, one end of the eccentric shaft being connected with the feed dog frame, characterized in that the adjusting mechanism comprises an electromagnet, a mounting frame, a linkage rod, a limiting rod, an elastic member, a limiting wheel fixed to the other end of the eccentric shaft and a driver fixed to the housing, the electromagnet being fixed to the housing through the mounting frame, the mounting frame having a plurality of gear holes, the core of the electromagnet being fixed with a gear plate, the gear plate being fixed with a gear pin, the top of the linkage rod being hinged with the gear plate and the bottom being hinged with the limiting rod, the limiting wheel having a limiting portion protruding therefrom, the limiting portion abutting against the limiting rod under the action of the elastic member, a circumferential positioning structure being provided between the core of the electromagnet and the output shaft of the driver, when the core of the electromagnet extends, the output shaft of the driver drives the core to rotate through the circumferential positioning structure, and the rotation of the core drives the limiting rod to move through the gear plate and the linkage rod, when the core of the electromagnet retracts, the gear pin is embedded in the corresponding gear hole.

[0007] Initially, the gear pin is embedded in a gear hole, the position of the gear pin controls the position of the limiting rod through the gear plate and the linkage rod, and the limiting portion abuts against the limiting rod under the action of the elastic member, i.e. the position of the angle of the limiting wheel is controlled, thereby controlling the height of the feed dog frame through the eccentric shaft, so that the sewing machine is suitable for sewing a kind of thickness of sewing material. When adjusting, the electromagnet receives a signal, the core extends along the axis thereof, the output shaft of the driver is circumferentially positioned with the core through the circumferential positioning structure, then the output shaft of the driver rotates by a certain angle, the core is driven to rotate by a certain angle through the circumferential positioning structure, thereby changing the position of the gear pin, the position of the gear pin controls the limiting rod at another position through the gear plate and the linkage rod, so that the limiting wheel is positioned at another angle, thereby changing the height of the feed dog frame through the eccentric shaft, so that the sewing machine can be suitable for sewing another thickness of sewing material, then the core of the electromagnet retracts along the axis thereof, the output shaft of the driver is separated from the core, the gear pin is embedded in another gear hole to position the gear pin, thereby ensuring stability. The sewing machine cooperates the electromagnet, the driver and the circumferential positioning structure, so that the gear pin can be arranged in different gear holes, thereby making the feed dog frame at different heights, so that the sewing machine can be suitable for sewing different thickness of sewing material, the adjusting device is adjusted in an automatic manner, and the adjustment is convenient.

[0008] In the above-mentioned sewing machine thickness adjusting device, the core of the electromagnet is coaxially arranged with the output shaft of the driver, and the core of the electromagnet and the output shaft of the driver are oppositely arranged. This structure makes the structure of the circumferential positioning structure simple, and the circumferential positioning structure can better realize the circumferential positioning of the core and the output shaft of the driver, and the output shaft of the driver can better drive the core to rotate.

[0009] In the above-described sewing machine thickness adjusting device, the mounting frame comprises a mounting ring in a ring shape and a mounting plate in a plate shape, one end of the mounting plate is fixedly connected with the mounting ring, the mounting frame is fixedly connected with the housing by fastening the mounting plate through the housing, the electromagnet is fixedly arranged in the mounting ring, and the gear hole is arranged in the mounting ring. The mounting frame plays a role of mounting the electromagnet and positioning the gear pin, and the structure is simplified.

[0010] In the above-described sewing machine thickness adjusting device, the linkage rod is in a bent shape, and the top of the linkage rod is arranged in a horizontal direction and offset from the bottom of the linkage rod. The structure enables the linkage rod to better connect the gear plate and the limiting rod, and enables the thickness adjusting device to be more reasonably arranged when mounted outside the housing.

[0011] In the above-described sewing machine thickness adjusting device, the inner end of the gear plate is fixedly connected with the iron core, the outer end has a hinge hole in a strip shape and used for being hingedly connected with the linkage rod, and the gear plate gradually increases in width from the inner end to the outer end. The structure guarantees the strength of the gear plate, saves materials, and enables the linkage rod and the gear plate to not be stuck when relatively rotating.

[0012] In the above-described sewing machine thickness adjusting device, the circumferential positioning structure comprises a positioning groove arranged in a recessed manner on the iron core and a positioning protrusion arranged in a protruding manner on the output shaft of the driver, when the iron core of the electromagnet is extended, the positioning protrusion is embedded into the positioning groove to enable the iron core and the output shaft of the driver to be circumferentially positioned, and when the iron core of the electromagnet is retracted, the positioning protrusion is separated from the positioning groove to enable the iron core and the output shaft of the driver to be separated. The circumferential positioning of the iron core and the output shaft of the driver is realized by the cooperation of the recessed and protruding structures, the structure is simple, the stability of the circumferential positioning is good, and in actual production, the positioning groove can be arranged on the output shaft of the driver and the positioning protrusion can be arranged on the iron core.

[0013] In the above-described sewing machine thickness adjusting device, the output shaft of the driver is provided with an accommodating groove at one end close to the electromagnet, the accommodating groove is fixedly connected with a positioning block through a fastening piece, the positioning block comprises the positioning protrusion arranged in a protruding manner, the positioning protrusion is arranged outside the circumferential outer wall of the output shaft of the driver, the positioning groove comprises a main groove and a secondary groove arranged in a protruding manner outside the main groove, and when the iron core of the electromagnet is extended, the output shaft of the driver is partially embedded into the main groove and the positioning protrusion is embedded into the secondary groove. The structure increases the contact area and guarantees the stability of the circumferential positioning of the output shaft of the driver and the iron core.

[0014] In the above-described sewing machine thickness adjusting device, the outer side wall of the shell has a recessed avoidance slot, the shell is further fixedly connected with a limiting plate, the limiting plate is located at the slot opening of the avoidance slot, the limiting rod is L-shaped, the limiting rod is partially located in the avoidance slot, the top of the long side of the limiting rod is hingedly connected with the bottom of the linkage rod, and the outer end of the short side of the limiting rod is in contact with the limiting portion. The installation space is provided by the avoidance slot, the limiting of the limiting rod is realized by the cooperation of the slot bottom of the avoidance slot and the limiting plate, the limiting rod moves along the set path, the stability of the adjusting device during adjustment is ensured, and the adjustment accuracy is improved.

[0015] In the above-described sewing machine thickness adjusting device, the elastic member is a tension spring, the limiting portion is in a strip shape, one end of the elastic member acts on the outer end of the limiting portion, and the other end acts on the shell. The structure is simple through the tension spring pulling, and the limiting portion can also be moved by the spring in actual production.

[0016] In the above-described sewing machine thickness adjusting device, the output shaft of the driver is further fixedly connected with a thread cutting cam for driving the sewing machine cutter to rotate, a first eccentric wheel for driving the sewing machine presser foot to work, and a second eccentric wheel for driving the eccentric shaft to reciprocate. The sewing machine can realize the actions of cutting, lifting the presser foot, and the feeding tooth movement of the sewing machine through one driver, and can realize the height adjustment of the feeding tooth frame, so that the sewing machine is suitable for sewing different thicknesses of sewing materials, that is, four actions of the sewing machine can be realized through one driver, the design is ingenious, and the cost is reduced.

[0017] Compared with the prior art, the sewing machine thickness adjusting device provided by the application has the following advantages:

[0018] 1. The gear position pin can be arranged in different gear holes through the cooperation of the electromagnet, the driver, and the circumferential positioning structure, so that the feeding tooth frame can be at different heights, the sewing machine can be suitable for sewing different thicknesses of sewing materials, and the adjusting device is adjusted in an automatic mode, so that the adjustment is convenient.

[0019] 2. The output shaft of the driver of the sewing machine is fixedly connected with a plurality of components, the plurality of components are connected with the cutter, the presser foot, and the feeding tooth frame of the sewing machine through corresponding structures, the height adjustment of the feeding tooth frame can be realized, that is, four actions of the sewing machine can be realized through one driver, the design is ingenious, and the cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is an external structure schematic view of the sewing machine.

[0021] Figure 2 It is a structure schematic view of the thickness adjusting device installed on the sewing machine.

[0022] Figure 3 is the structural schematic diagram of the thickness adjusting device of the sewing machine.

[0023] Figure 4 is the structural schematic diagram of the driver and electromagnet of the sewing machine.

[0024] In the figure, 1, housing; 2, feed dog frame; 3, eccentric shaft; 4, electromagnet; 41, core; 5, mounting bracket; 51, gear hole; 52, mounting ring; 53, mounting plate; 6, linkage rod; 7, limiting rod; 8, elastic member; 9, limiting wheel; 91, limiting part; 10, driver; 101, output shaft; 11, gear plate; 111, hinged hole; 12, gear pin; 13, positioning groove; 131, main body groove; 132, auxiliary body groove; 14, positioning block; 141, positioning protrusion; 15, accommodating groove; 16, avoiding groove; 17, limiting plate; 18, thread trimming cam; 19, first eccentric wheel; 20, second eccentric wheel. DETAILED DESCRIPTION

[0025] The following is a specific embodiment of the present application and further describes the technical solutions of the present application in conjunction with the drawings, but the present application is not limited to these embodiments.

[0026] As shown in Figure 1 , the sewing machine comprises a housing 1, a feed dog frame 2, an eccentric shaft 3 and a thickness adjusting device, the adjusting mechanism comprising an electromagnet 4, a mounting bracket 5, a linkage rod 6, a limiting rod 7, an elastic member 8, a limiting wheel 9 and a driver 10. As shown in Figure 4 , the output shaft 101 of the driver 10 is fixedly connected with a thread trimming cam 18 for driving the rotating of the cutter of the sewing machine, a first eccentric wheel 19 for driving the work of lifting the presser foot of the sewing machine and a second eccentric wheel 20 for driving the reciprocating swing of the eccentric shaft 3.

[0027] The driver 10 is fixedly connected to the housing 1, the mounting bracket 5 comprises a mounting ring 52 in the form of a ring and a mounting plate 53 in the form of a plate, one end of the mounting plate 53 is fixedly connected to the mounting ring 52, the mounting bracket 5 is fixedly connected to the housing 1 by means of fasteners such as bolts passing through the mounting plate 53 and into the housing 1, the electromagnet 4 is fixedly arranged in the mounting ring 52, the core 41 of the electromagnet 4 is coaxially arranged with the output shaft 101 of the driver 10, and the core 41 of the electromagnet 4 and the output shaft 101 of the driver 10 are oppositely arranged. The mounting ring 52 has gear holes 51, in this embodiment, the number of gear holes 51 is three, in actual production, the number of gear holes 51 can be two or four.

[0028] As shown in Figure 2 , Figure 3As shown, the circumferential positioning structure is arranged between the core 41 of the electromagnet 4 and the output shaft 101 of the driver 10, and comprises a positioning groove 13 recessed on the core 41 and a positioning protrusion 141 protruded on the output shaft 101 of the driver 10. The end of the output shaft 101 of the driver 10 close to the electromagnet 4 is provided with a receiving groove 15, and the positioning block 14 is embedded in the positioning groove 13 and fixed to the output shaft 101 of the driver 10 by a fastener such as a bolt. The positioning block 14 comprises the protrusion 141 protruded outside the circumferential outer wall of the output shaft 101 of the driver 10. The positioning groove 13 comprises a main groove 131 and a secondary groove 132 protruded outside the main groove 131. When the core 41 of the electromagnet 4 is extended, the output shaft 101 of the driver 10 is partially embedded in the main groove 131 and the protrusion 141 is embedded in the secondary groove 132, so that the core 41 and the output shaft 101 of the driver 10 are circumferentially positioned. When the core 41 of the electromagnet 4 is retracted, the protrusion 141 is separated from the positioning groove 13, so that the core 41 and the output shaft 101 of the driver 10 are disengaged.

[0029] One end of the eccentric shaft 3 is connected to the feed dog frame 2, and the other end of the eccentric shaft 3 is fixedly connected to a limiting wheel 9. The limiting wheel 9 has a limiting portion 91 protruded thereon, and the limiting portion 91 abuts against the limiting rod 7 under the action of the elastic member 8. Specifically, the elastic member 8 is a tension spring, and the limiting portion 91 is in a strip shape. One end of the elastic member 8 acts on the outer end of the limiting portion 91, and the other end acts on the housing 1.

[0030] The core 41 of the electromagnet 4 is fixedly connected to a gear plate 11, and the gear plate 11 is fixedly connected to a gear pin 12. The inner end of the gear plate 11 is fixedly connected to the core 41, and the outer end has a hinge hole 111 in a strip shape for being hingedly connected to the linkage rod 6. The gear plate 11 gradually increases in width from the inner end to the outer end. The linkage rod 6 is in a bent shape, and the top of the linkage rod 6 is arranged in a horizontal direction and offset from the bottom of the linkage rod 6. The top of the linkage rod 6 is hingedly connected to the gear plate 11, and the bottom is hingedly connected to the limiting rod 7. The outer side wall of the housing 1 has a recessed avoiding groove 16, and the housing 1 is further fixedly connected to a limiting plate 17 located at the slot opening of the avoiding groove 16. The limiting rod 7 is in an L shape, and part of the limiting rod 7 is located in the avoiding groove 16. The top of the long side of the limiting rod 7 is hingedly connected to the bottom of the linkage rod 6, and the outer end of the short side of the limiting rod 7 is in contact with the limiting portion 91.

[0031] At the beginning, the gear pin 12 is embedded in a gear hole 51, and the position of the gear pin 12 controls the position of the limiting rod 7 through the gear plate 11 and the linkage rod 6, i.e. controls the position of the limiting wheel 9, so as to control the height of the feed dog frame 2 through the eccentric shaft 3. During adjustment, the electromagnet 4 receives a signal, and the iron core 41 extends along its own axis, so that the output shaft 101 of the driver 10 is positioned circumferentially with the iron core 41, and then the output shaft 101 of the driver 10 rotates by a certain angle, and drives the iron core 41 to rotate by a certain angle through the circumferential positioning structure, so as to change the position of the gear pin 12, and the gear pin 12 controls the limiting rod 7 in another position through the gear plate 11 and the linkage rod 6, so as to fix the limiting wheel 9 at another angle, so as to change the height of the feed dog frame 2 through the eccentric shaft 3, and then the iron core 41 of the electromagnet 4 moves along its own axis, and the output shaft 101 of the driver 10 and the iron core 41 are separated, the gear pin 12 is embedded in another gear hole 51, and the adjustment is completed.

[0032] The specific embodiments described herein merely exemplify the spirit of the present application. Those skilled in the art to which the present application pertains can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, without departing from the spirit of the present application or exceeding the scope defined by the appended claims.

[0033] Although the terms such as the housing 1, the feed dog frame 2, the eccentric shaft 3, the electromagnet 4, the iron core 41, the mounting frame 5, the gear hole 51, the mounting ring 52, the mounting plate 53, the linkage rod 6, the limiting rod 7, the elastic member 8, the limiting wheel 9, the limiting part 91, the driver 10, the output shaft 101, the gear plate 11, the hinge hole 111, the gear pin 12, the positioning groove 13, the main body groove 131, the auxiliary body groove 132, the positioning block 14, the positioning protrusion 141, the accommodating groove 15, the avoiding groove 16, the limiting plate 17, the thread trimming cam 18, the first eccentric wheel 19, the second eccentric wheel 20, etc. are used more frequently herein, the possibility of using other terms is not excluded. The use of these terms is only for the convenience of describing and explaining the essence of the present application; any kind of additional limitation by interpreting them is contrary to the spirit of the present application.

Claims

1. A thickness adjustment device for a sewing machine, the sewing machine comprising a housing (1), a feed dog (2), and an eccentric shaft (3), one end of the eccentric shaft (3) being connected to the feed dog (2), characterized in that, The adjustment mechanism includes an electromagnet (4), a mounting bracket (5), a linkage rod (6), a limiting rod (7), an elastic element (8), a limiting wheel (9) fixed to the other end of the eccentric shaft (3), and a driver (10) fixed to the housing (1). The electromagnet (4) is fixed to the housing (1) via the mounting bracket (5). The mounting bracket (5) has several stop holes (51). A stop plate (11) is fixed to the iron core (41) of the electromagnet (4). A stop pin (12) is fixed to the stop plate (11). The top of the linkage rod (6) is hinged to the stop plate (11), and the bottom is hinged to the limiting rod (7). The limiting wheel (9) has a... A protruding limiting part (91) is provided, which abuts against the limiting rod (7) under the action of the elastic member (8). A circumferential positioning structure is provided between the iron core (41) of the electromagnet (4) and the output shaft (101) of the driver (10). When the iron core (41) of the electromagnet (4) extends, the output shaft (101) of the driver (10) drives the iron core (41) to rotate through the circumferential positioning structure. The rotation of the iron core (41) drives the limiting rod (7) to move through the gear plate (11) and the linkage rod (6). When the iron core (41) of the electromagnet (4) retracts, the gear pin (12) is embedded in the corresponding gear hole (51).

2. The thickness adjustment device for a sewing machine according to claim 1, characterized in that, The core (41) of the electromagnet (4) is coaxially arranged with the output shaft (101) of the driver (10), and the core (41) of the electromagnet (4) and the output shaft (101) of the driver (10) are arranged opposite to each other.

3. The thickness adjustment device for a sewing machine according to claim 1, characterized in that, The mounting bracket (5) includes an annular mounting ring (52) and a plate-shaped mounting plate (53). One end of the mounting plate (53) is fixedly connected to the mounting ring (52). The mounting bracket (5) is fixedly connected to the housing (1) by fasteners passing through the mounting plate (53) and into the housing (1). The electromagnet (4) is fixedly installed in the mounting ring (52). The stop hole (51) is located in the mounting ring (52).

4. A sewing machine thickness adjustment device according to claim 1, 2, or 3, characterized in that, The linkage rod (6) is bent, and the top of the linkage rod (6) is offset from the bottom of the linkage rod (6) in the horizontal direction.

5. A sewing machine thickness adjustment device according to claim 1, 2, or 3, characterized in that, The inner end of the gear plate (11) is fixedly connected to the iron core (41), and the outer end has a long strip-shaped hinge hole (111) for hinged with the linkage rod (6). The width of the gear plate (11) gradually increases from the inner end to the outer end.

6. A sewing machine thickness adjustment device according to claim 1, 2, or 3, characterized in that, The circumferential positioning structure includes a positioning groove (13) recessed on the iron core (41) and a positioning protrusion (141) protruding on the output shaft (101) of the driver (10). When the iron core (41) of the electromagnet (4) extends, the positioning protrusion (141) is embedded in the positioning groove (13) to circumferentially position the iron core (41) and the output shaft (101) of the driver (10). When the iron core (41) of the electromagnet (4) retracts, the positioning protrusion (141) leaves the positioning groove (13) to disengage the iron core (41) and the output shaft (101) of the driver (10).

7. A sewing machine thickness adjustment device according to claim 6, characterized in that, The output shaft (101) of the driver (10) has a receiving groove (15) at one end near the electromagnet (4). A positioning block (14) is fixed in the receiving groove (15) by fasteners. The positioning block (14) includes a positioning protrusion (141) that protrudes from the outer circumferential wall of the output shaft (101) of the driver (10). The positioning groove (13) includes a main groove (131) and a secondary groove (132) that protrudes from the main groove (131). When the iron core (41) of the electromagnet (4) extends out, the output shaft (101) of the driver (10) is partially embedded in the main groove (131) and the positioning protrusion (141) is embedded in the secondary groove (132).

8. A sewing machine thickness adjustment device according to claim 1, 2, or 3, characterized in that, The outer side wall of the housing (1) has a recessed clearance groove (16), and a limiting plate (17) is fixedly connected to the housing (1). The limiting plate (17) is located at the opening of the clearance groove (16). The limiting rod (7) is L-shaped and part of the limiting rod (7) is located in the clearance groove (16). The top of the long side of the limiting rod (7) is hinged to the bottom of the linkage rod (6), and the outer end of the short side of the limiting rod (7) is in contact with the limiting part (91).

9. A sewing machine thickness adjustment device according to claim 1, 2, or 3, characterized in that, The elastic element (8) is a tension spring, the limiting part (91) is long and narrow, one end of the elastic element (8) acts on the outer end of the limiting part (91), and the other end acts on the housing (1).

10. A sewing machine thickness adjustment device according to claim 1, 2, or 3, characterized in that, The output shaft (101) of the driver (10) is also fixedly connected to a thread-cutting cam (18) for driving the sewing machine cutter to rotate, a first eccentric wheel (19) for driving the sewing machine presser foot to work, and a second eccentric wheel (20) for driving the eccentric shaft (3) to reciprocate.

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