TWI550156B - Sewing machine under the trimming mechanism - Google Patents

Description

Sewing machine under the thread cutting mechanism

The invention relates to a bottom thread trimming mechanism suitable for a sewing machine, in particular to a lower thread trimming mechanism which is mounted on an automatic sewing machine base of a sewing button hole for cutting a bottom thread.

At present, an automatic tangential structure is installed on the existing automatic sewing button hole sewing machine, and the main purpose thereof is to separate the sewing thread from the cloth by the cutting method of the automatic tangential structure after the cloth is put into the starting sewing position, thereby saving sewing. Labor and time.

Referring to FIG. 1 , the lower thread cutter of the prior sewing machine comprises a needle plate structure 30 , a thread catching mechanism 31 , a wire mechanism 32 , a rocker link mechanism 33 and a lever 34 . The above-mentioned tangential mechanism 32 includes an upper cutting edge 321 , a lower cutting edge 322 connected to the lower edge of the upper cutting edge 321 , and a pressing piece 323 attached to the bottom surface of the lower cutting edge 322 . The upper and lower cutting edges 321 , 322 are interposed between the needle plate structure 30 and Between the thread catching mechanisms 31, a bolt is inserted through one end of the upper cutting edge 321 to connect the lower portion of the needle plate structure 30, and the lower cutting edge 322 can be pivotally swung with respect to the upper cutting edge 321 and the crimping piece 323 to perform a cutting line.

The rocker arm mechanism 33 includes a rocker arm 331 and a link 332. The rocker arm 331 is respectively provided with a push rod 331a and a limiting post 331b, and the bottom end of the rocker arm 331 is transmitted through a driving device. The drive lever 34 is coupled to the needle plate structure 30 for pushing the cutting edge of the lower blade 322 to be opened and transmitted through another driving device (not shown).

However, in the existing lower thread cutter structure, the upper cutting edge 321 can only swing around the fulcrum thereof, and it is impossible to systematically configure the standby position, the preparation trimming position, and the trimming action position, respectively. When the thread trimming operation is performed, the above-mentioned tangential mechanism 32 must pass through two different sets of driving devices (figure The rocker link mechanism 33 and the lever 34 are respectively driven to rotate the rocker link mechanism 33 and the lever 34 in opposite positive and counterclockwise directions, thereby completing the thread trimming operation of the suture.

In view of the current position limitation of the blade cutter of the existing sewing machine and the tangential mechanism must be driven by a plurality of different rods and driving sources, it is possible to complete the capturing and cutting of the suture. Therefore, it is necessary to design a The system can be configured to systematically configure the moving position of the blade and the lower trimming mechanism that simplifies the number of components to reduce manufacturing costs.

The main object of the present invention is to provide a lower thread cutting mechanism for driving the wire cutter group to move horizontally, so that the wire cutter group can be repeatedly moved from the standby position of the needle plate holder to the deployment position during the guided movement. And move to the preparation position while remaining in the unfolded state, then move to the trimming position to complete the cutting action, and finally return to the standby position of the needle plate holder to complete a trimming cycle.

The secondary object of the present invention is to have a guiding device that cooperates with the slider between the wire cutter group and the needle plate seat, and cooperates with a special pushing design on the needle plate seat, so that a single linkage member can be transmitted through the single linkage member. The complete cutting action of the thread cutting knife group to complete the unfolding, displacement, trimming and resetting greatly simplifies the structural complexity of the lower thread cutting mechanism and the number of components.

In order to achieve the above object, the lower thread trimming mechanism of the present invention is mainly mounted on a base of a sewing machine, and comprises a driving device forming a driving source, a needle plate seat mounted on the base, a wire cutter group for performing suture cutting, and a A wire clamping device for maintaining the tension of the thread, wherein the needle plate holder and the wire cutter group have a guiding device.

The driving device of the present invention is provided with a driving motor. The driving motor is connected with a cam and drives the cam to reciprocally rotate, and the cam drives the plurality of connecting rod members to swing.

A needle plate is mounted on the needle plate holder of the present invention, and a groove is provided at the bottom portion, and the surrounding area of the groove has at least one stopper.

The wire cutter group of the present invention is installed in a groove at the bottom of the needle plate seat, and is connected with the link group of the driving device, and can be displaced by the link group, and has two mutually pivoting blades, wherein One blade is a fixed blade and the other blade is a movable blade that can be relatively yawed.

The wire clamping device of the present invention is connected to the other link group of the driving device, and has a first clamping arm and a second clamping arm that is matched and clamped, and the first clamping arm is pivotally connected with the connecting rod set, and the above The second clamping arm is pivotally disposed on the needle plate seat, and is located on the swinging path of the first clamping arm pivoting, and the first clamping arm is biased by the connecting rod group to generate a yaw, and then the first clamping arm is further The second clamping arm is driven to perform a reverse swing.

The guiding device is composed of at least one guiding slot and a corresponding guiding guiding pin, and the guiding slot and the guiding pin are respectively disposed on the needle plate seat and the wire cutter group, wherein the guiding slot A motion trajectory is formed, and the guide pin is restricted to move in the motion trajectory of the guiding slot.

The invention is characterized in that the guiding device between the needle plate holder and the wire cutter group can cause relative movement between the needle plate holder and the wire cutter group along a set motion trajectory, when the wire cutter group is subjected to The driving device drives the wire cutter group to generate a displacement path along the movement track in the groove, and the blade moves to contact the stopper to generate a relative oscillation, so that the two blades can be repeatedly An action between an unfolded state and a closed state. The wire cutter group of the invention completes the unfolding, displacement, trimming and resetting actions during the parallel movement process, thereby completing a suture cutting.

In a preferred embodiment, the guide groove and the guide pin of the present invention are a set of mutually matching guide grooves and sliders, and the action track of the guide groove has a guide for guiding the two blades to form the open state. A path and a second path for guiding the two cutting edges to form the closed state.

Wherein, the first path has a standby position of an un-clamped suture, and the end portion forms an open position for unfolding the two cutting edges, and the second path has a clamping position for positioning the suture, and the end portion A cutting position is formed which closes the two cutting edges.

In addition, the needle plate holder is provided with a first positioning piece and a second positioning piece to sandwich the wire cutter group in the groove, and the block is formed on the first positioning piece and the second positioning piece respectively. In the opposite direction, the two cutting edges of the above-mentioned string cutter group are sequentially pushed by one of the two stoppers during the displacement operation.

In another embodiment, the stopper of the present invention can be integrally extended from the bottom of the needle plate holder to form a bump structure at two fixed positions.

In addition, the wire clamping device of the present invention comprises an elastic member, one end of the elastic member is mounted on the bottom of the needle plate holder, and the other end is connected to the second clamping arm, and the elastic member is used to drive the second clamping arm. A forward swinging, and a stop pin is further disposed on the bottom of the needle plate seat, and the reverse swing of the second clamp arm is limited to the needle plate position.

The invention is characterized in that the lower thread trimming mechanism directly drives the wire cutter group to move in the horizontal direction through the first link group of the driving device, and the wire cutter group is subjected to the action between the guiding groove and the guiding pin. The reciprocating displacement will be performed along a set motion trajectory, and when the thread cutter group moves to both ends of the motion trajectory, it will be subjected to the stopper to cause the two blades to pivot open or close each other, thus allowing the thread cutter group to be moved. During the movement, it is repeatedly moved from the standby position of the needle board seat to the deployed position, and moves to the preparation position while remaining in the unfolded state, then moves to the trimming position to complete the cutting action, and finally returns to the standby position of the needle board seat. Complete a trimming cycle.

Since the lower thread trimming mechanism of the present invention connects the wire cutter group through a single link group, the movement and the blade edge opening and closing operations are completed, the structure complexity of the lower thread trimming mechanism and the number of components are greatly simplified, and the lower thread trimming mechanism can be effectively reduced. The space occupied inside the sewing machine.

[study]

30‧‧‧needle plate structure

31‧‧‧Line-catching agency

32‧‧‧ Thread cutting mechanism

321‧‧‧Upper blade

322‧‧‧ lower blade

323‧‧‧Crimping film

33‧‧‧ rocker linkage

331‧‧‧ rocker arm

331a‧‧‧Put

331b‧‧‧Limited Column

332‧‧‧ linkage

34‧‧‧

〔this invention〕

10‧‧‧Sewing machine

11‧‧‧ head

12‧‧‧Base

20‧‧‧ drive

201‧‧‧Drive motor

202‧‧‧ shaft

203‧‧‧fixed board

204‧‧‧ cam

204a‧‧‧first groove track

204b‧‧‧second groove track

205‧‧‧First wheel

206‧‧‧First Link Group

206a‧‧‧ swing arm

206b‧‧‧ activity pole

207‧‧‧Second wheel

208‧‧‧Second linkage

208a‧‧‧ swinging rod

208b‧‧‧ linkage rod

21‧‧‧ needle seat

211‧‧‧ needle board

211a‧‧‧ pinhole

211b‧‧‧Cutter hole

212‧‧‧ guiding slot

212a‧‧‧Action track

212b‧‧‧First path

212c‧‧‧second path

213‧‧‧ Groove

214‧‧ ‧block

215‧‧ ‧block

216‧‧‧First positioning piece

217‧‧‧Second positioning piece

22‧‧‧Thread cutter group

221‧‧‧ displacement plate

222‧‧‧ Guide pin

223‧‧‧first blade

224‧‧‧second blade

225‧‧‧Crimping film

226‧‧‧ convex

227‧‧‧ convex

23‧‧‧Clamping device

231‧‧‧First clamp arm

231a‧‧‧First pivot end

231b‧‧‧First clamping end

231c‧‧‧ push block

232‧‧‧Second clamp arm

232a‧‧‧Second pivotal end

232b‧‧‧Second clamping end

233‧‧‧Flexible parts

234‧‧‧Distribution

1 is an exploded view of a lower thread cutting mechanism of a conventional sewing machine; FIG. 2 is a perspective view of a lower thread cutting mechanism of the present invention attached to a sewing machine base; FIG. 3 is a perspective view of a lower thread cutting mechanism of the present invention; 3 is an exploded view of the thread cutting mechanism; Fig. 5 is a sectional view taken along line AA' of Fig. 3; Fig. 6 is a bottom view of the hidden driving motor of the lower thread cutting mechanism of the present invention; and Fig. 7 is a needle of the present invention; FIG. 8A is a schematic view showing a standby position of the wire cutter group of the present invention in an unactuated state; FIG. 8B is a view showing a wire cutter of the present invention corresponding to a wire cutter group in a non-operating manner; Schematic diagram of the standby position of the state; FIG. 9A is a schematic view of the wire cutter group of the present invention at the position of the loose wire; FIG. 9B is a schematic view of the wire clamping device of the present invention corresponding to the position of the wire cutter group; FIG. 10A is the present invention FIG. 10B is a schematic view of the wire clamping device of the present invention corresponding to the wire cutting tool set in the position where the wire cutting is prepared; FIG. 11A is the wire cutting tool group of the present invention in the position where the wire cutting is completed. Schematic diagram; and FIG. 11B is a corresponding shearing device of the present invention A schematic diagram of the wire cutter set at the completion of the trimming.

For a more detailed and detailed understanding and understanding of the structure, the use and the features of the present invention, the preferred embodiment will be described in detail with reference to the drawings as follows: First, please refer to FIG. 2 to FIG. As shown, the lower thread trimming mechanism of the sewing machine 10 of the present invention is located at a sewing position of the base 12 corresponding to the front end 11, and mainly comprises: a driving device 20, a needle plate seat 21, a wire cutter group 22 and a wire clamping device 23 The driving device 20 is located inside the base 12 and provides power to form a driving source; the needle plate seat 21 is mounted on the reserved opening position of the base 12; the wire cutter group 22 is located on the needle plate. The suture cutting operation is performed below the seat 21; and the above-mentioned wire clamping device 23 is also located below the needle plate holder 21 to capture the suture, thereby maintaining the suture tension.

As shown in FIG. 4, the driving device 20 of the present invention is provided with a driving motor 201 having a rotating shaft 202, and the driving motor 201 is mounted on a fixing plate 203, and a cam 204 is pivotally connected by the rotating shaft 202, and is driven. The cam 204 performs a reciprocating rotation, and the cam 204 is provided with a first groove track 204a and a second groove track 204b.

In addition, the first groove 204a is coupled to a first roller set 205, and the second groove 204b is coupled to a second roller 207 to a second link set 208. The connecting rod set 206 is provided with a swing arm 206a and a movable rod 206b which are pivotally connected to the first roller 205 at the same time. The other end of the swing arm 206a is pivotally disposed on the fixing plate 203, and the other end of the movable rod 206b is And the second link group 208 is provided with a swinging rod 208a pivotally connected to the second roller 207 at one end, and the central position of the swinging rod 208a is pivoted, and then The other end of the swing lever 208a is connected to a linkage rod 208b, and the other end of the linkage rod 208b is pivotally connected to the wire clamping device 23.

Referring to FIG. 4 to FIG. 6 , the needle plate holder 21 of the present invention has a needle plate 211 and at least one guiding groove 212 , and a recess for receiving the wire cutter group 22 is concavely formed in the bottom portion. 213 (such as the 5th As shown in the figure, and the surrounding area of the above-mentioned groove 213 has two stoppers 214, 215 which cooperate with the above-mentioned string cutter group 22.

In the preferred embodiment of the present invention, the needle plate holder 21 is provided with a first positioning piece 216 and a second positioning piece 217 for confining the wire cutter group 22 to the groove 213; and the needle plate 211 A pinhole 211a and all the holes 211b are formed. The two stoppers 214 and 215 are respectively formed on the first positioning piece 216 and the second positioning piece 217.

Please refer to FIG. 7 , however, the design of the two blocks 214 and 215 is for convenience of illustration and is not limited; in another embodiment, the two blocks 214 and 215 may also be used. The bump structure of the two fixed positions is directly formed by the bottom of the needle plate holder 21 integrally formed.

Referring to FIG. 4 and FIG. 6 again, the wire cutter group 22 of the present invention has a displacement plate 221 located inside the groove 213, and the displacement plate 221 is provided with a guide corresponding to the combination of the guiding grooves 212. The pin 222 has a first cutting edge 223 extending from one end and pivotally connected to the movable rod 206b of the first connecting rod set 206. The bottom surface of the displacement plate 221 is pivotally formed to cooperate with the first cutting edge 223 to form a cutting edge. a second cutting edge 224 of the mouth and a pressing piece 225, wherein the first cutting edge 223 is a non-rotating fixed cutting edge, the second cutting edge 224 is a movable cutting edge yawable relative to the first cutting edge 223, and the second A convex portion 226, 227 corresponding to the stoppers 214, 215 is respectively extended on both sides of the blade 224.

The wire clamping device 23 of the present invention is provided with a first clamping arm 231 and a second clamping arm 232. The first clamping arm 231 has a first pivoting end 231a and a first clamping end mounted with the needle plate seat 21. 231b, the linkage rod 208b of the second link group 208 is pivotally connected to the first clamping arm 231, and the first clamping arm 231 is further provided with a pushing block 231c for driving the second clamping arm 232.

In addition, the second clamping arm 232 also has a second pivoting end 232a and a second clamping end 232b that are mounted on the needle plate base 21, and the second clamping arm 232 is pivoted on the pushing block 231c. In the swinging path, when the second link set 208 drives the first clamping arm 231 to generate a yaw, the first clamping arm 231 pushes the second clamping arm 232 to generate a counterclockwise swinging deployment.

Furthermore, the second clamping arm 232 is further provided with an elastic member 233. One end of the elastic member 233 is connected to the second clamping arm 232, and the other end is mounted on the bottom of the needle plate holder 21. When the second connecting rod set 208 is returned. In the first clamping arm 231, the elastic member 233 drives the second clamping arm 232 to perform a clockwise swinging closure.

Thus, the interaction between the second link set 208 and the elastic member 233 can be performed to form a forward and reverse swing of the first clamp arm 231 and the second clamp arm 232 in a direction opposite to each other. In this embodiment, a pin 234 is further disposed on the bottom of the needle plate base 21 to limit the position of the second clamp arm 232 to at most only the needle plate 211.

The guiding device 212 and the guiding pin 222 form a guiding device, and the guiding device overlaps with the groove 213, and the guiding groove 212 forms an action track 212a, and the guiding pin 222 is received by the guiding pin 212 It is limited to move in the motion locus 212a of the above-described guiding groove 212.

In the preferred embodiment of the present invention, the motion path 212a of the present invention has a first path 212b for guiding the first blade 223 and the second blade 224 to form the open state (refer to FIG. 9A) and a guiding The one edge 223 and the second cutting edge 224 form the second path 212c in the above closed state (see FIG. 11A).

The structure design of the lower thread trimming mechanism of the present invention can be known from the foregoing description, but the following will explain the action patterns and connection relationships between each member during the completion of one trimming cycle, please refer to Fig. 8A and As shown in FIG. 8B, when the driving device 20 is not in operation, the guiding pin 222 of the displacement plate 221 will be located in the first path 212b, and a standby state is formed adjacent to the intersection of the second path 212c.

At this time, the convex portion 226 of the second cutting edge 224 is not in contact with the stopper 214 of the first positioning piece 216. And the second clamping arm 232 of the wire clamping device 23 is pushed by the first clamping arm 231, and forms a deployment state with the first clamping arm 231 without holding the suture (in the pinhole 211a). The elastic member 233 is stretched by the second clamp arm 232 to have an elastic restoring force.

Referring to FIGS. 9A and 9B, when the driving device 20 drives the guiding pin 222 of the displacement plate 221 to move to the end of the first path 212b, the convex portion 226 of the second cutting edge 224 will be subjected to The stopper 214 of the first positioning piece 216 is pushed to form a blade open state after the first blade 223 is relatively oscillated. At the same time, the first clamping arm 231 and the second clamping arm 232 of the above-mentioned wire clamping device 23 will maintain the same deployment state as the standby state.

Referring to FIGS. 10A and 10B, when the driving device 20 drives the guiding pin 222 of the displacement plate 221, the end portion of the first path 212b moves to a clamping position in the second path 212c. There is no change in the relative position between the first cutting edge 223 and the second cutting edge 224. At the same time, the first clamping arm 231 of the wire clamping device 23 is biased by the second link group 208 to position the first clamping end 231b toward the pinhole 211a, and the second clamping arm 232, due to the looseness of the first clamping arm 231, is subjected to the elastic restoring force of the elastic member 233, and the second clamping arm 232 is reversely biased to contact the stopper pin 234, and the first clamping arm 231 will be The second clamp arm 232 collectively captures the suture and brings the suture to a designated position.

Please refer to FIG. 11A and FIG. 11B again. Then, when the driving device 20 drives the guiding pin 222 of the displacement plate 221 to move to the end of the second path 212c, the other convexity of the second cutting edge 224 The portion 227 is pushed by the stopper 215 of the second positioning piece 217, and is relatively oscillated with the first blade 223 to form a blade closed state, thereby completing the thread trimming operation.

At the same time, the second clamping arm 232 of the wire clamping device 23 is incapable of being operated by the stopper pin 234, and the first clamping arm 231 is biased toward the overlapping position of the second clamping arm 232, and the sewing stitch is moderately tightened. The first cutting edge 223 and the second cutting edge 224 cannot be accurately cut completely due to insufficient stitch tension.

Finally, when the driving device 20 drives the guiding pin 222 of the displacement plate 221, the end portion of the second path 212c moves to the standby position in the first path 212b (the same position as the seventh drawing), and the lower trimming line of the present invention The organization did indeed complete a trimming process.

It can be seen from the above description that the present invention can cause the needle plate holder 21 and the string cutter group 22 to be generated along a set motion track 212a through the guiding device between the needle plate holder 21 and the thread cutter group 22. When the wire cutter group 22 is driven by the driving device 20, the wire cutter group 22 generates a displacement path in the groove 213 which is the same as the motion track 212a, and moves the second blade 224. Upon contact with the stoppers 214, 215, a relative oscillation is generated, so that the first blade 223 and the second blade 224 can repeatedly operate between an unfolded state and a closed state.

The above embodiments are intended to be illustrative only, and are not intended to limit the scope of the present invention. It is included in the scope of the following patent application.

20‧‧‧ drive

201‧‧‧Drive motor

202‧‧‧ shaft

203‧‧‧fixed board

204‧‧‧ cam

204a‧‧‧first groove track

204b‧‧‧second groove track

205‧‧‧First wheel

206‧‧‧First Link Group

206a‧‧‧ swing arm

206b‧‧‧ activity pole

207‧‧‧Second wheel

208‧‧‧Second linkage

208a‧‧‧ swinging rod

208b‧‧‧ linkage rod

21‧‧‧ needle seat

211‧‧‧ needle board

211a‧‧‧ pinhole

211b‧‧‧Cutter hole

212‧‧‧ guiding slot

212a‧‧‧Action track

212b‧‧‧First path

212c‧‧‧second path

214‧‧ ‧block

215‧‧ ‧block

216‧‧‧First positioning piece

217‧‧‧Second positioning piece

22‧‧‧Thread cutter group

221‧‧‧ displacement plate

222‧‧‧ Guide pin

223‧‧‧first blade

224‧‧‧second blade

225‧‧‧Crimping film

226‧‧‧ convex

227‧‧‧ convex

23‧‧‧Clamping device

231‧‧‧First clamp arm

231a‧‧‧First pivot end

231b‧‧‧First clamping end

231c‧‧‧ push block

232‧‧‧Second clamp arm

232a‧‧‧Second pivotal end

232b‧‧‧Second clamping end

233‧‧‧Flexible parts

Claims (8)

A sewing machine lower thread cutting mechanism is mounted on a base of a sewing machine, comprising: a driving device having a driving motor, and connecting a cam by the driving motor, the plurality of connecting rod groups being driven by the cam; a needle plate seat, mounting The base has a needle plate, and at least one stopper and a groove are formed at the bottom; a wire cutter group is installed in the groove at the bottom of the needle plate seat, is connected with the driving device, and is connected by the above The rod group is driven to generate displacement, and has two mutually arranging blades; and a guiding device is disposed between the needle plate seat and the wire cutter group, and is composed of at least one guiding groove and correspondingly connected guiding pins, The guiding groove forms an action track, and the guiding pin is restricted to move in the motion track of the guiding slot; wherein the wire cutter group is driven by the driving device to generate a a displacement path having the same motion trajectory, and causing the blade to move into contact with the stopper to generate a relative oscillation, so that the two blades can be repeatedly between an unfolded state and a closed state. Make. 55. The sewing machine lower thread cutting mechanism according to claim 1, wherein the guiding groove and the guiding pin are respectively disposed on the needle plate seat and the wire cutter group. According to the sewing machine lower thread trimming mechanism of claim 1, wherein the action track has a first path for guiding the two blades to form the open state and a second path for guiding the two blades to form the closed state. According to the sewing machine lower thread trimming mechanism of claim 3, wherein the first path has a standby position without an unstitched stitch, and the end portion forms an open position for expanding the two cutting edges, The second path has a clamping position for positioning the suture, and the end portion forms a clipping position for closing the two cutting edges. According to the sewing machine lower thread trimming mechanism of claim 1, wherein the needle plate seat is provided with a first positioning piece and a second positioning piece to restrain the wire cutter group in the groove. According to the sewing machine lower thread cutting mechanism of claim 5, wherein the above-mentioned stoppers are respectively formed on the first positioning piece and the second positioning piece, and the two cutting edges of the wire cutting knife group are in the process of displacement The sequence is pushed by one of the above two stops. According to the sewing machine lower thread trimming mechanism of claim 1, wherein the above-mentioned stopper pushing unit is a bump structure integrally formed by the bottom of the needle board seat to form a fixed position. According to the sewing machine lower thread trimming mechanism of claim 1, wherein the lower thread trimming mechanism further comprises a wire clamping device connected to the driving device and driven by another link group; the wire clamping device has a first clamp An arm and a second clamping arm that cooperates with the clamping, the first clamping arm is pivotally connected to the connecting rod set, and the second clamping arm is pivotally disposed on the needle plate seat and is pivoted on the first clamping arm In the swinging path, the second clamping arm is driven by the first clamping arm to perform a reverse swing.