A positioning device for the feed dog of a sewing machine

Abstract

The present application proposes a positioning device for the feed dog of a sewing machine, which specifically relates to the technical field of sewing machine manufacturing, and includes a positioning device, wherein the power source of the positioning device acts on the tooth rack of the sewing machine, so that the tooth tip of the tooth rack is positioned and lower than the plane of the needle plate of the sewing machine; the limiting baffle of the positioning device acts on the fork crank limiting groove of the fork crank, the fork crank movable connecting sleeve is arranged on the tooth lifting shaft, and the tooth lifting slider groove of the fork crank is movably connected to the tooth lifting slider of the tooth rack, so that the tooth tip of the tooth rack is positioned and lower than the plane of the needle plate of the sewing machine, and the tooth tip of the tooth rack is implemented by the above-mentioned specific positioning device to stay below the plane of the needle plate. The positioning device of the present application is set on the sewing machine for use, which fully improves the intelligent control level of the sewing machine, reduces the labor intensity of the operator, and at the same time, the sewing quality is further improved.

Description

Technical Field

[0001] The present application provides a positioning device for a feed dog of a sewing machine, and specifically relates to the technical field of sewing machine manufacturing. Background Art

[0002] In the textile industry, the presser foot of a sewing machine is an essential part of the sewing process. It is used to press the fabric to be sewn against the feed dog to ensure the flatness of the fabric during movement, so that the stitches after sewing are neat and beautiful. The presser foot and feed dog of the sewing machine work in coordination to complete the sewing. However, at the end of sewing, the position where the feed dog stays is often higher than the needle plate. In this case, it is necessary to manually adjust the hand wheel to make the feed dog sink below the needle plate, which increases the workload of the operator. If the operator does not find that the feed dog is too high, the feed dog is likely to hook the fabric when sewing begins, and the fabric is easily damaged. Summary of the invention

[0003] In view of the defects existing in the stop position of the feed dog of the existing sewing machine, the technical problem to be solved by the present application is to provide a positioning device for the feed dog of the sewing machine, characterized in that it includes a positioning device, and the power source of the positioning device indirectly acts on the feed dog of the sewing machine, so that the tip of the feed dog is positioned and lower than the upper plane of the needle plate of the sewing machine. The above scheme is the technical effect to be achieved by the present invention.

[0004] Preferably, the power source pushes the limit baffle to act on the fork crank limit groove of the fork crank, the fork crank movably connected sleeve is arranged on the tooth lifting shaft, the tooth lifting slider groove of the fork crank is movably connected to the tooth lifting slider of the tooth rack, so that the tooth tip of the feed tooth is positioned and lower than the upper plane of the needle plate of the sewing machine, and the above-mentioned specific positioning device is implemented to achieve the tooth tip of the feed tooth staying below the upper plane of the needle plate.

[0005] Preferably, the limit baffle is fixed on a baffle bracket of the positioning device, the baffle bracket is movably connected to the output shaft of the positioning device, the baffle bracket has an idle swing hole, the idle swing hole is movably connected to the tooth lifting crank movable rod, and the output shaft is connected to the power source. The above arrangement effectively realizes the mutual offset of the swing sources and is a key design link in achieving the technical effect.

[0006] Preferably, the limit baffle is fixed to the middle part of the baffle bracket, and the baffle bracket and the power source are provided with springs.

[0007] Preferably, the tooth lifting crank movable rod has a clutch portion that matches the tooth lifting sleeve limiting groove of the tooth lifting sleeve and the fork crank limiting groove of the fork crank, and the tooth lifting sleeve limiting groove and the fork crank limiting groove together form a clutch space for the tooth lifting crank movable rod. The setting of the above-mentioned clutch space facilitates the transmission of the swing source between the tooth lifting sleeve limiting groove and the fork crank limiting groove.

[0008] Preferably, the fixed axial hole of the tooth-lifting shaft sleeve is used to be fixed on the tooth-lifting shaft, and the axial hole of the fork-shaped crank is used for the dynamic connecting sleeve to be arranged on the tooth-lifting shaft.

[0009] Preferably, the fork crank is movably connected to the tooth lifting shaft by a washer and a hexagon socket cylindrical screw.

[0010] Preferably, the tooth lifting shaft is divided into two sections, and the tooth lifting shaft sleeve and the fork crank are installed adjacent to each other.

[0011] Compared with the prior art, the beneficial effect of the present application is: by using the positioning device to position the feed dog at the end of sewing, the feed dog is allowed to stay below the plane of the needle plate, so that the feed dog's staying position can be lower than the plane of the needle plate each time, thereby effectively solving the adverse factors caused by the feed dog being higher than the plane of the needle plate. The positioning device of the present application is set on the sewing machine for use, which fully improves the intelligent control level of the sewing machine, reduces the labor intensity of the operator, and at the same time the sewing quality is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a structural diagram of a positioning device for a feed dog of a sewing machine according to the present application;

[0013] Figure 2 This is a schematic diagram of a positioning device for a feed dog of a sewing machine according to the present application, in which a limit baffle acts on a fork-shaped crank;

[0014] Figure 3 This is a feed dog position diagram of a positioning device for a feed dog of a sewing machine according to the present application;

[0015] Figure 4 This is a structural diagram of a limit baffle and baffle bracket of a positioning device for a feed dog of a sewing machine according to the present application;

[0016] Figure 5 It is a rear view of a baffle bracket of a positioning device for a feed dog of a sewing machine according to the present application;

[0017] Figure 6 This is a structural diagram of a fork-shaped crank of a positioning device for a feed dog of a sewing machine according to the present application;

[0018] Figure 7 The present invention discloses a structure diagram of a tooth-lifting shaft sleeve of a positioning device for a feed dog of a sewing machine.

[0019] Figure markings: feed dog 1, tooth tip 12, tooth rack 13, tooth lifting slider 14, upper plane 2 of needle plate, tooth lifting shaft 4, tooth lifting sleeve 41, fixed shaft hole 411, tooth lifting sleeve limiting groove 412, fork crank 42, tooth lifting slider groove 421, shaft hole 422, fork crank limiting groove 423, positioning device 50, output shaft 51, baffle bracket 52, idle swing hole 521, connecting end 522, limiting baffle 53, tooth lifting crank movable rod 54, clutch part 541, axial elastic retaining ring 55, screw 56, spring 57, power source 58, washer 6, hexagon socket screw 7. DETAILED DESCRIPTION

[0020] The preferred embodiments of the present application are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present application can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present application. These implementation modes are only used to illustrate the present invention, and are not intended to limit the present invention.

[0021] Embodiment 1

[0022] Figure 1 Figure 2 Figure 3 and Figure 4 The present application shows a positioning device for a feed dog of a sewing machine, and the sewing machine includes a positioning device 50, a tooth lifting shaft 4, a fork crank 42, a tooth lifting shaft sleeve 41, a feed dog 1, and a plane 2 on the needle plate. The feed dog 1 is mounted and fixed on the tooth frame 13, and the power source 58 of the positioning device 50 acts indirectly on the feed dog 1 of the sewing machine to position the feed dog 1 and its tooth tip 12. The positioning device 50 implements the positioning of the feed dog 1 to achieve the positioning of the tooth tip 12 of the feed dog 1 after the sewing is completed, and to make the tooth tip 12 be in a state lower than the plane 2 on the needle plate of the sewing machine, so as to overcome the defect that the tooth tip 12 is higher than the plane 2 on the needle plate at the end of sewing, and the fabric is hooked and damaged during the next sewing.

[0023] In the swing source transmitted from the sewing machine main shaft motor to the tooth lifting shaft 4, the tooth lifting crank movable rod 54 of the positioning device 50 transmits the swing source of the tooth lifting shaft sleeve 41 to the fork crank 42, and then transmitted to the tooth lifting slider 14 and its tooth frame by the tooth lifting slider groove 421 of the fork crank 42, and finally transmitted to the feed dog 1. This is the process of the sewing machine tooth lifting shaft 4 with the positioning device 50 of the present application transmitting the swing source to the feed dog 1. The tooth lifting sleeve 41 is fixed on the tooth lifting shaft 4, the fork crank 42 movable connecting sleeve is arranged on the tooth lifting shaft 4, the clutch mechanism of the positioning device 50 is the tooth lifting crank movable rod 54 and the limit baffle 53, the tooth lifting crank movable rod 54 is used to clutch and transmit the swing source between the fork crank 42 and the tooth lifting sleeve 41, the power source 58 pushes the limit baffle 53 to act on the fork crank limit groove 423 of the fork crank 42, and the tooth lifting crank movable rod 54 and the limit baffle 53 work simultaneously with the power source 58. When the feed dog 1 driven by the fork crank 42 is in a low position, the limit baffle 53 is selected to implement the positioning of the feed dog 1, so that the tooth tip 12 of the feed dog 1 is positioned and below the upper plane 2 of the needle plate of the sewing machine. That is, when the last stitch of sewing is about to be finished, the feed dog 1 is in a low position, and the power source 58 is commanded by the electronic control device of the sewing machine software, and the power source 58 drives the limit baffle 53 to perform the positioning action of inserting into the fork crank limit groove 423, so that the tooth tip 12 stops below the upper plane 2 of the needle plate of the sewing machine. After the tooth tip 12 is positioned, the limit baffle 53 enters the fork crank limit groove 423 of the fork crank 42, and the tooth lifting crank movable rod 54 is separated from the fork crank 42 and retracted into the tooth lifting sleeve limit groove 412 of the tooth lifting sleeve 41.

[0024] Refer to the attached figure and combine Figure 5 Figure 6 and Figure 7The positioning device 50 includes auxiliary components such as an output shaft 51, a baffle bracket 52, a limit baffle 53, a tooth lifting crank movable rod 54 and a power source 58. The limit baffle 53 is fixed on the baffle bracket 52 with a screw 56. The limit baffle 53 of this embodiment is fixed at the middle position of the baffle bracket 52; the baffle bracket 52 and the output shaft 51 are dynamically connected. Specifically, the output shaft 51 is dynamically connected to the baffle bracket 52 with two axial elastic retaining rings 55. When the limit baffle 53 is inserted into the fork crank limit groove 423 of the fork crank 42, if there is an angular deviation between the limit baffle 53 and the fork crank 42, it will be offset by the dynamic connection between the output shaft 51 and the limit baffle 53, so it will not directly act on the output shaft 51. The baffle bracket 52 has an idle swing hole 521, and the idle swing hole 521 is movably connected to a connection end 522 of a tooth lifting crank movable rod 54, and the tooth lifting crank movable rod 54 is movably connected to the baffle bracket 52 by two axial elastic retaining rings 55. The idle swing hole 521 is used to receive the swing source transmitted by the tooth lifting shaft 4 to the tooth lifting shaft sleeve 41, so that the connection end 522 of the tooth lifting crank movable rod 54 is idle in the idle swing hole 521. In addition, the baffle bracket 52 and the power source 58 are provided with a spring 57.

[0025] The above-mentioned tooth lifting crank movable rod 54 has a clutch part 541 that matches the tooth lifting sleeve limiting groove 412 of the tooth lifting sleeve 41 and the fork crank limiting groove 423 of the fork crank 42. When the swing source transmitted by the tooth lifting shaft 4 reaches the tooth lifting sleeve 41, the tooth lifting crank movable rod 54 is between the tooth lifting sleeve limiting groove 412 and the fork crank limiting groove 423, and the swing source is transmitted from the tooth lifting sleeve 41 to the fork crank 42 via the tooth lifting crank movable rod 54. This is the detailed action process of feeding and sewing of the feed dog 1 under normal conditions. When the feed dog 1 is to be positioned, the power source 58 is controlled to issue a command to retract the limit baffle 53 and the tooth lifting crank movable rod 54 at the same time, and the limit baffle 53 enters the fork crank limit groove 423 of the fork crank 42, first stopping the fork crank 42 from swinging, and then successfully positioning the feed dog 1; at the same time, the tooth lifting crank movable rod 54 disengages from the fork crank limit groove 423 of the fork crank 42 and enters the tooth lifting sleeve limit groove 412 of the tooth lifting shaft sleeve 41, at this time, the swing source continued to be transmitted by the tooth lifting shaft 4 is received by the tooth lifting shaft sleeve 41, and the tooth lifting shaft sleeve 41 drives the tooth lifting crank movable rod 54 to swing, and the swing source of the tooth crank movable rod 54 is offset by the idle swing in the idle swing hole 521, and will not produce a swinging effect on the limit baffle 53. The above-mentioned limiting baffle 53 is matched with the fork crank limiting groove 423, and the tooth lifting crank movable rod 54 is matched with the tooth lifting shaft sleeve limiting groove 412 and the fork crank limiting groove 423 to jointly form a clutch space for the tooth lifting crank movable rod 54, which is the core active component of the positioning device 50 of the present application to realize the positioning of the feed dog 1.

[0026] The fixed axial hole 411 of the tooth-lifting sleeve 41 is used to be fixed on the tooth-lifting shaft 4, and the axial hole 422 of the fork crank 42 is used to be movably connected and sleeved on the tooth-lifting shaft 4. The tooth-lifting sleeve 41 and the fork crank 42 are adjacent and installed at the end of the tooth-lifting shaft 4. The fork crank 42 is movably connected and sleeved on the tooth-lifting shaft 4 by a washer 6 and a hexagon socket screw 7.

[0027] In addition, after the positioning device 50 of the present application positions the feed dog 1, the power source 58 returns to its original position, so that the tooth crank movable rod 54 and the limit baffle 53 return to their original positions, and the limit baffle 53 is ready for the next positioning. When sewing next time, the sewing machine also needs to return to the initial position so that the subsequent sewing work can continue.

[0028] Embodiment 2

[0029] The second embodiment is basically the same as the first embodiment, except that the tooth lifting shaft sleeve 41 and the fork crank 42 are installed at different positions, so that the positioning device 50 matched therewith is also configured accordingly. In this embodiment, the tooth lifting shaft 4 is set as a two-stage type, the tooth lifting shaft sleeve 41 and the fork crank 42 are installed adjacently, and the positioning device 50 is also configured accordingly at the position for positioning the feed dog 1, and the technical effect is the same as that of the first embodiment.

[0030] The above description is only a preferred implementation mode of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A positioning device for a feed dog of a sewing machine, characterized in that: The invention comprises a positioning device (50), wherein the positioning device (50) comprises a fork crank (42), a baffle bracket (52), a limit baffle (53) and a power source (58), wherein the power source (58) acts indirectly on a feed dog (1) so that a tooth tip (12) of the feed dog (1) is positioned below an upper plane (2) of a needle plate of a sewing machine; The feed dog (1) is mounted and fixed on a tooth frame (13), the tooth frame (13) has a tooth lifting slider (14), the fork crank (42) is movably connected to the tooth lifting shaft (4), the fork crank (42) has a tooth lifting slider groove (421) and a fork crank limiting groove (423), the power source (58) pushes the limiting baffle (53) to act on the fork crank limiting groove (423), the tooth lifting slider groove (421) is movably connected to the tooth lifting slider (14); the limiting baffle (53) is fixed on the baffle bracket (52), the baffle bracket (52) is movably connected to the output shaft (51), the output shaft (51) is connected to the power source (58), the baffle bracket (52) has an idle swing hole (521), the idle swing hole ( 521) is dynamically connected to a tooth-lifting crank movable rod (54), the tooth-lifting crank movable rod (54) has a clutch portion (541), the tooth-lifting shaft sleeve (41) has a fixed shaft hole (411) and a tooth-lifting shaft sleeve limiting groove (412), the clutch portion (541) matches the tooth-lifting shaft sleeve limiting groove (412) and the fork crank limiting groove (423), the tooth-lifting shaft sleeve limiting groove (412) and the fork crank limiting groove (423) together form a clutch space for the clutch portion (541), the fixed shaft hole (411) is fixed on the tooth-lifting shaft (4), the shaft hole (422) of the fork crank (42) is dynamically connected and sleeved on the tooth-lifting shaft (4), and a spring (57) is provided between the baffle bracket (52) and the power source (58); When the swing source transmitted by the tooth-lifting shaft (4) reaches the tooth-lifting shaft sleeve (41), the clutch portion (541) is located between the tooth-lifting shaft sleeve limiting groove (412) and the fork-shaped crank limiting groove (423), and the swing source is transmitted from the tooth-lifting shaft sleeve (41) to the fork-shaped crank (42) via the clutch portion (541); when the feed dog (1) is to be positioned, the power source (58) is controlled to issue a command to retract the limit baffle (53) and the clutch portion (541) simultaneously, and the limit baffle (53) enters the fork-shaped crank limiting groove (423), first stopping the fork-shaped crank (42) from swinging, and then successfully positioning the feed dog (1).

2. A positioning device for a feed dog of a sewing machine according to claim 1, characterized in that: The limiting baffle (53) is fixed at the middle position of the baffle bracket (52).

3. A positioning device for a feed dog of a sewing machine according to claim 1, characterized in that: The fork crank (42) is movably connected to the tooth lifting shaft (4) by a washer (6) and a hexagon socket cylindrical screw (7).

4. A positioning device for a feed dog of a sewing machine according to claim 1, characterized in that: The tooth lifting shaft (4) is divided into two sections, and the tooth lifting shaft sleeve (41) and the fork crank (42) are installed adjacent to each other.

5. A positioning device for a feed dog of a sewing machine according to claim 1, characterized in that: The output shaft (51) is movably connected to the baffle support (52) by two axial elastic retaining rings (55).

6. A positioning device for feed dogs of a sewing machine according to claim 1, characterized in that: The tooth lifting crank movable rod (54) is movably connected to the baffle bracket (52) by two axial elastic retaining rings (55).

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