TWI840959B - Sewing track switching device - Google Patents

Abstract

A sewing track switching device includes a rotating shaft unit, a cam unit, a lifting contact platform and an operating unit. The rotating shaft unit includes a rotating rod. The cam unit includes a track changing cam arranged around the rotating rod. The track changing cam has a ring portion and a plurality of track portions arranged in sequence from the ring portion. At least a part of the outer peripheral profile of the track portions is different from each other. The lifting contact platform extends The operating unit extends above the track change cam and can be abutted by one of the track parts to swing along the outer peripheral contour. The operating unit includes a track switching rod extending below the track change cam to carry the ring. The track switching rod can drive the track change cam to move along the rotating rod so that one of the track parts abuts against the lifting contact platform, so that the track parts can be selected according to needs.

Description

Sewing track switching device

The present invention relates to a sewing machine, and more particularly to a sewing track switching device.

An existing sewing machine, when performing sewing operations, can take up the thread by rotating a cam to link the feed teeth located above to swing up and down.

However, each type of fabric has the most suitable take-up action (that is, the most suitable feed tooth oscillation trajectory) when taking up the thread, and the outer peripheral profile of a single cam can only correspond to one feed tooth oscillation trajectory, so when changing to other types of fabric, the best take-up effect cannot be obtained.

Therefore, the purpose of the present invention is to provide a sewing track switching device that overcomes the shortcomings of the prior art.

Therefore, the sewing track switching device of the present invention is applied to a sewing machine having a frame, and the sewing track switching device includes a rotating shaft unit, a cam unit, a lifting contact platform, and an operating unit.

The shaft unit includes a rotating rod disposed in the frame and extending along an axis and being driven to rotate around the axis, a set set disposed on the rotating rod, and a cam stop ring disposed on the rotating rod and spaced from the set set. The cam unit includes a trajectory changing cam disposed around the rotating rod and located between the set set and the cam stop ring and being rotated in conjunction with the rotating rod, and an elastic member abutting against the set set and the trajectory changing cam at two opposite ends to apply an elastic force to the trajectory changing cam in a direction opposite to the set set. The trajectory changing cam has a ring portion and a plurality of self-actuating members. The ring has track parts arranged in sequence along the axis, and at least a part of the outer peripheral contours of the track parts are different from each other. The lifting contact platform is pivoted to the frame and extends above the track change cam, and can be abutted by one of the track parts and swing along the outer peripheral contour. The operating unit includes a bracket arranged on the frame, and a track switching rod arranged on the bracket and extending below the track change cam to carry the ring. The track switching rod can drive the track change cam to move along the rotating rod so that one of the track parts abuts against the lifting contact platform.

The effect of the present invention is that by providing the rotating rod, the track changing cam and the track switching rod, the track parts can be adjusted and selected according to needs to be suitable for different fabrics, thereby improving applicability.

2: Rotating shaft unit

21: Rotating rod

22:Kit

23: Cam stop ring

24: Positioning pin

3: Cam unit

31: Track changing cam

311: Environmental Protection Department

312: Track Department

313: Card support

32: Elastic parts

321: Helical segment

322: Card section

33: Positioning slot

4: Lifting contact table

5: Operation unit

51: Bracket

52: Track switching lever

521: Support rod joint

522: Carrying unit

523: Butt rod

524: Positioning hinge

53: Positioning plate

531:Surroundings

532: Card slot

54: Switch slot

55: Switch positioning rod

56: hinge pin

57: Switch positioning spring

9:Sewing machine

91:Frame

L: axis

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, wherein: FIG. 1 is a three-dimensional exploded view of an embodiment of the sewing track switching device of the present invention and a sewing machine; FIG. 2 is a three-dimensional assembly view of the embodiment; FIG. 3 is a three-dimensional exploded view of the embodiment; FIG. 4 is a use schematic diagram of the embodiment, illustrating a state where a switching positioning rod is located in a slot on the right side; FIG. 5 is a view similar to FIG. 4, illustrating a state where the switching positioning rod moves to a switching slot; and FIG. 6 is a view similar to FIG. 5, illustrating a state where the switching positioning rod moves to another slot on the left side.

Referring to Figures 1, 2, and 3, an embodiment of the sewing track switching device of the present invention is applied to a sewing machine 9 having a frame 91. The sewing track switching device includes a rotating shaft unit 2, a cam unit 3, a lifting contact platform 4, and an operating unit 5.

The rotating shaft unit 2 includes a rotating rod 21 disposed in the frame 91 and extending along an axis L and being driven to rotate around the axis L, a sleeve 22 disposed on the rotating rod 21, a cam stop ring 23 disposed on the rotating rod 21 and spaced from the sleeve 22, and a positioning pin 24 disposed on the rotating rod 21.

The cam unit 3 includes a track changing cam 31 which is arranged around the rotating rod 21 and is located between the set 22 and the cam stop ring 23 and can be rotated in conjunction with the rotating rod 21, an elastic member 32 which respectively abuts against the set 22 and the track changing cam 31 at two opposite ends to apply an elastic force to the track changing cam 31 in a direction opposite to the set 22, and a positioning groove 33 which is located at the track changing cam 31 and is open in at least one direction along the extension direction of the axis L. In this embodiment, the positioning groove 33 is open in a direction opposite to the elastic member 32, and the positioning pin 24 is inserted into the positioning groove 33 so that when the rotating rod 21 rotates, the track changing cam 31 can be rotated in conjunction with the positioning pin 24.

The track changing cam 31 has a ring portion 311, four track portions 312 arranged in sequence along the axis L from the ring portion 311 on a side of the ring portion 311 opposite to the elastic member 32, and a stop portion 313 connected to the ring portion 311 adjacent to a side of the elastic member 32. At least a portion of the outer peripheral profiles of the track portions 312 are different from each other. The elastic member 32 has a spiral section 321 spirally wound around the rotating rod 21, and a stop portion 322 connected to the spiral section 321 adjacent to a side of the track changing cam 31 and corresponding to the stop portion 313.

The lifting contact platform 4 is pivoted to the frame 91 and extends above the track change cam 31, and can be abutted by one of the track portions 312 and swing along the outer peripheral contour.

The operating unit 5 includes a bracket 51 disposed on the frame 91, a track switching rod 52 movably disposed on the bracket 51 and extending to the bottom of the track changing cam 31 to carry the ring 311, a positioning plate 53 disposed on the frame 91, a switching groove 54 formed on the positioning plate 53, a switching positioning rod 55 movably disposed on the track switching rod 52 and passing through the switching groove 54, a pivot pin 56 passing through the track switching rod 52 and the switching positioning rod 55, and a switching positioning spring 57 wound around the pivot pin 56 to constantly push against the switching positioning rod 55.

When the track switching rod 52 is swung relative to the bracket 51, it can drive the track changing cam 31 to move along the rotating rod 21, so that one of the track portions 312 abuts against the bottom of the lifting contact platform 4. The track switching rod 52 has a support rod pivoting portion 521 pivoted to the bracket 51, a supporting portion 522 connected to the support rod pivoting portion 521 to support the ring portion 311, an abutting rod 523 extending upward from the supporting portion 522 and located on a side of the ring portion 311 opposite to the elastic member 32, and a positioning pivoting portion 524 connected to a side of the supporting portion 522 opposite to the support rod pivoting portion 521 for the pivoting pin 56 to pivot.

The positioning plate 53 has a surrounding portion 531 surrounding the switching slot 54, and four slots 532 spaced along the swing direction of the track switching rod 52 and connected to the switching slot 54. The position of each slot 532 corresponds to the position where the respective track portion 312 abuts against the lifting contact platform 4, and the switching positioning spring 57 constantly causes the switching positioning rod 55 to swing toward the direction of the slots 532.

When the switch positioning rod 55 is inserted into each slot 532, the adjacent surrounding portion 531 can restrict the switch positioning rod 55 and the track switch rod 52 from swinging. In this embodiment, the slots 532 are located above the switch slot 54.

Referring to Figures 1, 3, and 4, when in use, the sewing machine 9 is used to sew a cloth (not shown), and the rotating rod 21 will be rotated by the operation of the sewing machine 9, and drive the track change cam 31 to rotate together. At this time, one of the track parts 312 abuts against the bottom of the lifting contact platform 4, and during the rotation process, the lifting contact platform 4 is pushed up and down along the outer peripheral contour of one of the track parts 312, so that a feed tooth (not shown) arranged above the lifting contact platform 4 is linked to assist the sewing machine 9 in winding up.

Referring to Figures 1, 3, and 5, when the sewing machine 9 is to sew another type of cloth, it only needs to pull the switching positioning rod 55 to overcome the elastic force of the switching positioning spring 57 and move downward from the corresponding slot 532 to the switching slot 54, and then it can move horizontally to make the track switching rod 52 swing relative to the bracket 51.

Referring to Figures 1, 3, and 6, when the track switching rod 52 swings, the track changing cam 31 will move along the rotating rod 21 after overcoming the elastic force of the elastic member 32, and move until one of the track portions 312 corresponding to the other type of fabric abuts against the bottom of the lifting contact platform 4, and then the switching positioning rod 55 is moved upward to another corresponding slot 532 by the elastic force of the switching positioning spring 57, and the positions of the switching positioning rod 55, the track switching rod 52, and the track changing cam 31 can be fixed, so that the sewing operation can continue.

Since the outer peripheral contours of the track portions 312 are all different and are designed to correspond to the best take-up track for different fabrics, the appropriate track portion 312 can be selected according to the needs to meet the needs of different fabrics, thereby achieving the best take-up effect.

In summary, by providing the rotating rod 21, the track changing cam 31, the track switching rod 52 and the switching positioning rod 55, the track portions 312 can be adjusted and selected as needed to be suitable for different fabrics, thereby improving applicability, and thus the purpose of the present invention can be achieved.

However, the above is only an example of the implementation of the present invention, and it cannot be used to limit the scope of the implementation of the present invention. All simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification are still within the scope of the patent of the present invention.

2: Rotating shaft unit 21: Rotating rod 22: Kit 23: Cam stop ring 24: Positioning pin 3: Cam unit 31: Track changing cam 311: Ring 312: Track section 313: Clamping section 32: Elastic member 321: Screw section 322: Clamping section 33: Positioning slot 4: Lifting contact table 5: Operation unit 51: Bracket 52: Track switching rod 521: Support rod pivot 522: Carrying section 523: Clamping rod 524: Positioning pivot 53: Positioning plate 531: Surrounding section 532: Clamping slot 54: Switching slot 55: Switching positioning rod 56: Pivot pin 57: Switching positioning spring L: Axis

Claims (8)

A sewing track switching device is applied to a sewing machine with a frame, and the sewing track switching device comprises: a rotating shaft unit, including a rotating rod arranged in the frame and extending along an axis and being driven to rotate around the axis, a set set arranged on the rotating rod, and a cam stop ring arranged on the rotating rod and spaced from the set set; a cam unit, including a track changing cam ring arranged on the rotating rod and located between the set set and the cam stop ring and being rotated in conjunction with the rotating rod, and an elastic member at two opposite ends respectively abutting against the set set and the track changing cam to apply an elastic force to the track changing cam in a direction opposite to the set set , the track change cam has a ring, and a plurality of track parts sequentially arranged from the ring along the axis, at least a part of the outer peripheral contours of the track parts are different from each other; a lifting contact platform, pivoted to the frame and extending above the track change cam, and can be abutted by one of the track parts and swing along the outer peripheral contour; and an operating unit, including a bracket arranged on the frame, and a track switching rod arranged on the bracket and extending below the track change cam to carry the ring, the track switching rod can drive the track change cam to move along the rotating rod so that one of the track parts abuts against the lifting contact platform. The sewing track switching device as described in claim 1, wherein the operating unit further includes a positioning plate arranged on the frame, a switching groove formed on the positioning plate, and a switching positioning rod arranged on the track switching rod and passing through the switching groove so as to be swingable up and down, the track switching rod can swing relative to the frame, the positioning plate has a surrounding portion surrounding the switching groove, and a plurality of slots arranged on the surrounding portion at intervals along the swinging direction of the track switching rod and connected to the switching groove, the position of each slot corresponds to the position where the respective track portion abuts against the lifting contact platform, and when the switching positioning rod is embedded in each slot, the surrounding portion adjacent to the slot can restrict the track switching rod from swinging. As described in claim 2, the sewing track switching device, wherein the operating unit further includes a pivot pin passing through the track switching rod and the switching positioning rod, and a switching positioning spring wound around the pivot pin to constantly swing the switching positioning rod toward the direction of the slots. The sewing track switching device as described in claim 3, wherein the track switching rod has a support rod pivoting portion pivoted to the bracket, a bearing portion connected to the support rod pivoting portion to support the ring portion, an abutment rod extending upward from the bearing portion and located on a side of the ring portion opposite to the elastic member, and a positioning pivoting portion connected to a side of the support rod pivoting portion opposite to the bearing portion for the pivot pin to pivot. The sewing track switching device as described in claim 1, wherein the track switching rod has a support rod pivoting portion pivotally connected to the bracket, a supporting portion connected to the support rod pivoting portion to support the ring portion, and an abutting rod extending upward from the supporting portion and located on a side of the elastic member opposite to the ring portion. As described in claim 1, the sewing track switching device, wherein the shaft unit further includes a positioning pin disposed on the rotating rod, and the cam unit further includes a positioning groove located on the track changing cam and open at least in one direction along the extension direction of the axis, the positioning groove is for the positioning pin to penetrate, so that when the rotating rod rotates, the track changing cam can be linked to rotate through the positioning pin. A sewing track switching device as described in claim 1, wherein the elastic member has a spiral section spirally wound around the rotating rod. As described in claim 7, the sewing track switching device, wherein the track changing cam also has a latching portion connected to the side of the ring portion adjacent to the elastic member, and the elastic member also has a latching section connected to the side of the spiral section adjacent to the track changing cam and corresponding to the latching portion.

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