TWI570295B - Cutting device for a sewing machine - Google Patents

Description

Sewing machine cutting mechanism (2)

The invention relates to a sewing machine cutting mechanism (2), which is a cutter structure for sewing a sewing machine while cutting a cloth edge.

According to the sewing machine cutting mechanism, the applicant has already approved the new case of "Sewing Machine Cuttering Mechanism" of Taiwan No. 90224735 and the "SEWING MACHINE" of the US No. 6892658. The case was created on the principle of parallel four-link group. The function of the cutter to stabilize the operation, and the lower cutter can be effectively adjusted to be close to or away from the needle plate, so that the patent is granted.

However, the inventor is not complacent, and has developed a kind of invention according to different transmission modes and innovations that continuously simplify the structure to reduce cost, thereby improving the convenience of use of the overall cutter mechanism and the stability of actuation. Sewing machine cutting mechanism (2).

The present invention provides a "sewing machine cutting mechanism (2)", wherein a long guiding guide structure is matched by a top cutter transmission member and a guide fixed to the base to improve the stability of the upper cutter movement. And with the integrated structure of the upper cutter transmission member, the upper cutter limiting device is more simple and reliable when it is placed thereon; and the lower cutter limiting device is pivoted on the base. The adjusting member is screwed with the lower cutter combined with the seat body, so that the end of the adjusting member is driven by a knob to achieve structural simplification, and the adjusting member and the knob can appropriately change the corresponding positions of the adjusting member to adjust the adjusting member to be adjusted. The angle of rotation is achieved for the purpose of adjusting the applicability of the rotatable range of the adjusting member and reducing the cost and stability of the component.

In order to achieve the above object, the present invention provides a "sewing machine cutting mechanism (2)", wherein the upper The cutter limiting device has an upper cutter transmission member with an upper cutter fixed at one end, and the other end of the upper cutter transmission member is driven by the upper cutter transmission device, and a rod-shaped guide portion is disposed at a middle portion thereof. The guiding portion passes through the guiding groove of a guiding member, and the guiding portion and the guide groove are guided by the guiding distance of the guiding groove to improve the stability of the action of the upper cutting blade transmission member, and the integrated upper cutting knife The upper cutter seat, the return spring, the limit body and the limit shaft in the cutter member matching the cutter limit device can be arranged in groups on the same, and achieve the purpose of integrating the structure and reducing the transmission member and the stable operation. .

Another object of the present invention is to provide a "sewing machine cutting mechanism (2)" which is provided with an adjusting hole which is threadedly engaged with an adjusting member on a lower cutter joint of a fixed lower cutter, and the adjusting member is The pivoting member is pivotally mounted on a lower cutter shaft fixed to the base, the adjusting member exposing the end of the lower cutter coupling seat and a knob to engage with the tooth shape, and the knob can be disengaged or re-installed according to the user's request. Engaged in the adjusting member to be driven or not, and the opposite and the lower guiding portion of the knob and the lower cutting knife are provided with opposite limiting portions and limiting portions, so that the knob can be in the arc length of the limiting portion The adjustment member rotates in the range, and the lower cutter joint on the adjusting member can move to the position close to or away from the needle plate, and when the lower cutter joint moves, there is still no place or other special position requirements. When the knob is disengaged from the adjusting member, the knob can be rotated by a desired angle, and then the knob is re-engaged with the adjusting member to facilitate the rotation of the adjusting member to expand or Reduce the rotation of the adjustment member Wai person.

A second object of the present invention is to provide a "sewing machine cutting mechanism (2)", wherein a pivot portion of a middle portion of a connecting cutter transmission device is pivotally mounted on a machine base, and the connecting rod is opposite to the lower cutting knife A sliding slot extending longitudinally along the longitudinal axis of the connecting rod is disposed at an end of the transmission member, and a power transmission member is slidably disposed in the sliding slot, and the power transmission member extends to a cylindrical shape at an end of the lower cutter transmission member. The shaft pivots are pivotally connected to each other and vertically move the lower cutter transmission member in a vertical direction, and the guiding member is arranged to cooperate with the moving direction of the lower cutter transmission member, so as to achieve the cutting action with the guide member Target person.

"Knowledge Technology"

A‧‧‧Cutter mechanism

10‧‧‧Sewing machine

11‧‧‧After

12‧‧‧ cantilever

13‧‧‧Drive shaft

14‧‧‧ needle board

111‧‧‧through shaft

140‧‧‧first needle board

141‧‧‧second needle board

31‧‧‧Upper knife

30‧‧‧Upper knife limiter

31‧‧‧Upper knife

40‧‧‧ Lower knife limiter

41‧‧‧Under the knife

"this invention"

112‧‧‧Card Department

21‧‧‧Active parts

22‧‧‧Drives

23‧‧‧ pivot

24‧‧‧ Connecting rod

240‧‧ ‧ chute

241‧‧‧ first end

242‧‧‧ second end

25‧‧‧Power transmission parts

250‧‧‧Axis

31‧‧‧Upper knife

310‧‧‧Adjustment hole

311‧‧‧ adjustment bolt

32‧‧‧Upper knife holder

320‧‧‧ seat

321‧‧‧ fixed sipe

322‧‧‧ pivot

33‧‧‧Return spring

34‧‧‧Limited body

340‧‧‧ center hole

341‧‧‧ Limit slot

35‧‧‧ Limit bolt

36‧‧‧Upper cutter transmission parts

360‧‧‧ Guide

361‧‧‧Extension

362‧‧‧Parts

363‧‧‧Pivot

364‧‧‧First wearing hole

365‧‧‧

366‧‧‧Second piercing

37‧‧‧ Guides

370‧‧‧ ear

371‧‧‧First perforation

372‧‧‧Second perforation

38‧‧‧ fixing bolt

373‧‧ ‧ guide slot

42‧‧‧ Lower cutter combined with seat

43‧‧‧Adjustment

44‧‧‧ knob

45‧‧‧ Lower cutter shaft

420‧‧‧Knife Department

421‧‧‧ vertical end

422‧‧‧guide hole

423‧‧‧Let the hole

424‧‧‧Adjustment hole

425‧‧‧Restriction Department

426‧‧‧Limited

43‧‧‧The adjustment piece

430‧‧‧With shaft hole

431‧‧‧passive teeth

434‧‧‧Adjustment Department

44‧‧‧ knob

441‧‧‧ notch

440‧‧‧Limited

442‧‧‧Active teeth

450‧‧‧ 容容

451‧‧‧End ring

Fig. 1 is a schematic view showing the structure of a cutting mechanism and a partial sewing machine of the present invention.

Fig. 2 is an exploded perspective view of the cutter mechanism of the present invention.

Fig. 3 is a schematic enlarged view of the knob of the cutting tool limiting device of the cutting mechanism of the present invention.

Fig. 4 is a schematic plan view showing the cutting mechanism of the present invention.

Figure 5 is a schematic cross-sectional view of the upper cutter limiting device of the present invention.

Fig. 6 is a schematic view showing the action of the upper cutter limiting device of the present invention.

Figure 7 is a schematic cross-sectional view of the lower cutter limiting device of the present invention.

Fig. 8 is a schematic view showing the detaching of the knob and the adjusting member of the downloading knife limit device of the present invention.

In order to enable your review committee to have a better understanding and understanding of the purpose, features and effects of the present invention, please refer to the following [simplified description of the drawings] for details:

As shown in the first, second, third, and fourth drawings, the cutter mechanism A of the present invention is disposed inside the base 11 of the sewing machine 10, and a cantilever is extended on the side of the base 11, and the inside of the base 11 is provided. A drive shaft 13 is provided to simultaneously drive the drive base 11 and the transmission member in the cantilever, and the free end of the cantilever has a stylus that moves up and down, and the base 11 is provided with a cutter mechanism A below the bur, and the base 11 A needle plate 14 is disposed above the cutter mechanism A. The needle plate 14 can be divided into a first needle plate 140 and a second needle plate 141. The cutter mechanism A has an upper cutter 31 and a lower cutter 41. And the transmission and the limiting device of the upper and lower cutters 31 and 41, wherein the machine housing 11 is further provided with a cutter transmission device 20 on the cutter mechanism A for driving the transmission shaft 13 to be linked a cutter 31, the base 11 is further provided with a protruding threading shaft 111 and a locking portion 112 arranged in a layer adjacent to the threading shaft 111 for respectively providing the knife limiting device 30 on the cutting mechanism A and The lower cutter limiting device 40 is disposed to change the position of the upper cutter 31 and the lower cutter 41 in the two devices and ensure the position of the lower cutter 41; , The present invention is based i.e. the fitting 40 is provided thereon by cutter 30 and lower cutter stop means limiting device, so that the upper cutter 31 and lower cutter gear 41 is more definite and are stabilized by a simplified structure.

The drive shaft 13 in the base 11 of the present invention is driven by a power source in the form of a motor, one end is interlocked with the upper cutter transmission device 20, and the upper cutter drive device 20 is disposed on the base 11 of the drive shaft. 13 is provided with a cam-coupled active member 21, and an annular ring portion at the end of a driving member 22 is sleeved on the cam of the driving member 21, and is screwed through the driving member 21 by a bolt and is urged to the driving shaft 13 The bottom end of the driving member 22 is driven by a first end 241 of a connecting rod 24 pivotally provided with a pivot 23 at a middle portion thereof. The two ends of the pivoting member 23 are pivotally disposed on the base 11, and the two ends of the connecting rod 24 are respectively The first end 241 and the second end 242 form a long slot 240 extending along the longitudinal direction of the connecting rod 24, and a sliding slot 240 is disposed along the sliding slot 240. The moving power transmission member 25 has a square shape at the end of the power transmission member 25 that slides in the sliding slot 240, and a cylindrical shaft extends from the cutter limiting device 30 above the cutter mechanism A. The pivot portion 250 pivotally drives the opposing members.

The upper cutter limiting device 30 has the upper cutter 31, the upper cutter base 32, a return spring 33, a limiting body 34 and a limit bolt 35. The upper cutter 31 is matched with the bottom elongated adjustment. Hole 310 and bolt form The screw of the adjusting bolt 311 is fixed, so that the upper cutter 31 is fixed to the fixed slot 321 of the seat portion 320 of the upper cutter base 32, and the outer diameter of the upper end surface of the upper cutter base 32 is smaller than the seat portion. The pivoting portion 322 of the sleeve 322 is passed through a central spring hole 340 of the ring-shaped spring 34, and the outer diameter structure of the limiting body 34 is matched with the outer diameter of the limiting body 34. The feature is that there is an upper cutter drive member 36 for the upper cutter holder 32 to pass through and the upper cutter holder 32 is placed thereon. The cutter transmission member 36 is then passed through the return spring 33 and the limiting body 34. The positioning bolt 35 is constrained between the upper cutter transmission member 36 and the limiting body 34. The positioning of the embodiment is performed. The bolt 35 is fixed on the upper cutter transmission member and restricts the limiting body 34. The middle portion of the upper cutter transmission member 36 is vertically disposed on a guide member 37 fixed to the base 11 and The upper cutter transmission member 36 is pivotally connected to the power transmission member 25 pivot portion 250 of the upper cutter transmission 20 through the end of the guide member 37, so that the link 24 can be moved via the power transmission member 25 when the link 24 is actuated. The moving direction of the guide on the guiding member 37 drives the cutter member 36.

The guide member 37 protrudes laterally from an ear piece 370, and the ear piece 370 is provided with a first through hole 371 having a small diameter perforation shape and a second hole 372 having a large diameter perforation shape at the lower side. The first through hole 371 is provided for the guide piece 37. A bolt-shaped fixing bolt 38 passes through and is screwed to the opposite side of the base 11, and the tab 370 is flatly attached to the surface of the base 11 and passes through the second through-hole 372. The guide 37 is provided. 370, the other end of the vertical square closed frame form a central guide groove 373 for the upper cutter transmission member 36 to pass through and guide, and the guide groove 373 has a certain length, thereby stably guiding the upper cutter transmission member 36 is slipped therein, and the outer wall of the guiding groove 373 is in close contact with the locking portion 112 of the base 11 to be mutually engaged, so that the guiding member 37 can be reliably positioned; At the same time, as shown in FIGS. 4 and 5, the upper cutter transmission member 36 is a quadrangular rod-shaped guide portion 360 in the vertical direction, and an extension portion 361 extending horizontally from the tip end of the guide portion 360 and an end portion of the extension portion 361. The abutting portion 362 of the short vertical free end is turned into an inverted J shape, wherein the guiding portion 360 has a length larger than the guiding groove 373 and is inserted into the guiding groove 373 at the middle portion to be surely guided in the vertical direction. The bottom portion of the guide portion 360 is provided with a pivot hole 363 for the shaft pivot portion 250 to pass through, so that the link 24 can drive the upper cutter drive member 36 to operate, and the upper cutter drive member 36 is driven. A first receiving hole 364 is defined in the connecting portion of the extending portion 361 and the guiding portion 360 for the upper cutting seat 32 to pass through. The bottom portion of the extending portion 361 is further provided with a downwardly protruding stopping edge 365. The abutting portion 362 is provided with a second receiving hole 366 at the first receiving hole 364 for the end of the upper cutting seat 32 to pass through the first and second receiving holes 364, 366. The return spring 33 and the limiting body 34 are arranged in series, and one end of the return spring 33 is disposed at the end of the first receiving hole 364, and the other end is adjacent to the limiting body 34. The body 34 is bolted to the upper cutter holder 32, and the upper cutter holder 32 can be pulled axially along the first and second insertion holes 364, 366. The limiting body 34 moves the restriction of the abutting portion 362 and the locking edge 365 within a certain stroke, and the abutting portion 362 is further provided with a fixing hole near the second receiving hole 366 for a limiting bolt 35 to pass through. The fixing pin is extended and the limit bolt 35 is extended to the outer diameter of the limiting body 34 to produce a mutual locking positioning effect.

The limiting body 34 is an annular structure with a central hole 340 at the center. The outer diameter is 180 degrees apart and each has a semi-circular concave limiting slot 341, so as to fit the limiting bolt 35 to the limit. The upper sleeve 341 of the body 34 is different, so that the upper cutter holder 32 that integrally rotates the limiting body 34 can simultaneously position the upper cutter 31 at different positions, please cooperate with the figure 6 as the user. To change the position of the upper cutter 31, the upper cutter holder 32 can be pulled to cause the limiting body 34 on the upper cutter holder 32 to leave the position locked with the limit pin 35 to the top of the limiting body 34 and the retaining edge 365. Simultaneously compressing the return spring 33, and then rotating the upper cutter holder 32 to the other limiting slot 341 of the limiting body 34, aligning the limiting pin 35, and directly releasing the hand, the return spring 33 can be used to limit the position. The body 34 is retracted to abut against the abutting portion 362. The limiting groove 341 of the limiting body 34 is positively engaged with the limiting pin 35, and the upper cutting seat 32 is no longer rotated.

The lower cutter limiting device 40 has a lower cutter 41, a lower cutter coupling base 42 coupled with the lower cutter 41, an adjustment member 43 and a cover screwed to the lower cutter coupling base 42 The knob 44 which is disposed at the end of the lower cutter joint base 42 and the lower cutter which is fixed to the base 11 at one end and protrudes from the other end of the base 11 to the center of the adjuster 43 The shaft 45; as shown in FIG. 7, the lower cutter 41 is matched with two sets of bolts fixed to the seat portion 420 of the top end of the lower cutter joint base 42 at the free end, and the lower cutter joint body 42 is a piece. a 7-shaped structure, a vertical elongated elliptical hole-shaped guide hole 422 and a large-diameter circular hole 423 are formed on the vertical end 421 to respectively pass through the shaft 111 to generate a locking force and The large-diameter head end of the fixing bolt 38 is disposed therebetween, and a adjusting hole 424 having a hollow tubular inner diameter and an internal thread shape is disposed at a turning portion of the lower cutting tool joint body 42. The adjusting hole 424 is surrounded by a limiting portion. 425, and a limiting portion 426 for stopping the limiting portion 425 is formed at the end of the limiting portion 425; the adjusting member 43 is a hollow cylinder The hollow portion is a through hole 430 for the lower cutter shaft 45 to protrude from the end of the base 11 to engage an E-type buckle on the lower cutter shaft 45, and the adjusting member 43 is positioned and pivoted On the lower cutter shaft 45, the outer diameter of the adjusting member 43 is equivalent to the adjusting hole 424, and a toothed tooth 431 having a surrounding tooth shape is disposed at an end of the lower cutter coupling base 42. The adjusting member 43 and the The outer diameter of the lower cutter jointing body 42 is adjusted to be an outer diameter of the adjusting portion 434; the knob 44 is a concave dome, and a notch 441 is formed on the end surface of the adjusting member 43. A flange-shaped limiting portion 440 extends from the periphery of the notch 441 to the lower cutter coupling seat 42 limiting portion 425 for limiting the limiting portion 426 of the limiting groove 425, and the inner diameter of the recess 441 is adjusted. The outer diameter of the piece 43 is equivalent, and The driving tooth 442 is provided with a surrounding tooth shape, and the driving tooth 442 is engaged with the passive tooth 431 of the adjusting member 43 to enable the knob 44 to positively rotate the adjusting member 43 to effectively change the lower cutting. The position of the knife-bonding base 42 on the adjusting member 43 is adjusted to adjust the position of the lower cutting blade to the base 42. The limiting portion 440 is further provided with an elastic card portion 443, and the knob 44 is sleeved on the passive tooth 432. The knob 44 is disposed at the end of the adjusting member 43 and is inserted into the adjusting member 43 at the end. After the card portion 443 passes over the passive tooth 432, the card portion 443 and the side edge of the other end of the passive tooth 431 are mutually engaged. Therefore, the knob 44 cannot be retracted from the driving tooth 442 to engage with the passive tooth 432 to form a retracted state; the card portion 443 is provided with a slot 444 at the periphery to form elasticity.

One end of the lower cutter shaft 45 is fixed on the base 11 , and the other end protrudes from the base 11 and is provided with a concave annular groove 450 for receiving a resilient retaining ring 451 and the retaining ring 451 The outer peripheral edge elastically abuts against the adjusting member 43 to prevent the adjusting member 43 and the lower cutting shaft 45 from generating unnecessary clearance to cause damage and noise of the vibration collision, and has a certain mud blocking effect.

When the driving teeth 442 of the knob 44 are engaged with the passive teeth 431 of the adjusting member 43 , the positions of the lower cutting tool joint body 42 can be adjusted to each other, and the limiting portion 440 of the knob 44 is stopped by the limiting portion 426 to The final point of the stroke, and when the adjusted position of the lower cutter combined with the seat 42 has not reached the correct position, the tool can be picked up and the card portion 443 is not locked with the passive teeth 432 to retreat the knob 44. The end of the adjusting member 43 causes the driving tooth 442 of the knob 44 to be separated from the position of the passive tooth 431 of the adjusting member 43. As shown in FIG. 8, the knob 44 can be rotated by a required angle and then re-opened. Pushing back to the position where the driving tooth 442 and the driven tooth 431 are engaged, the starting point of the rotating stroke of the adjusting member 43 can be redefined, and then the adjusting member 43 can be rotated by the knob 44 to adjust the lower portion. The cutter combines the position of the seat 42.

With the aforementioned structure, the following functions can be achieved, including:

1. The transmission structure is simplified: the guide member 37 is matched with the linear guiding structure of the cutter transmission member 36, and the structure of the connecting rod 24 of the cutter transmission device 20 is pivoted on the pivot shaft 23, and The simplified purpose of the transmission structure can be achieved.

2. The upper cutter limiting device is simplified: the upper cutter transmission member 36 is integrally designed for the relevant components of the upper cutter limiting device 30 to be installed, so that the structure related to the upper cutter is effectively simplified to reduce manufacturing. Cost associated with assembly.

3. The adjustment is more efficient: the knob 44 and the adjusting member 43 can be driven and not driven, and the adjustment structure of the adjusting member 43 and the lower cutter coupling base 42 is screwed to make the lower cutter The adjustable range of the combined seat 42 is larger and the adjustment structure is also a simplified design, which is in line with the purpose of efficiency.

"Knowledge Technology"

A‧‧‧Cutter mechanism

11‧‧‧After

13‧‧‧Drive shaft

111‧‧‧through shaft

140‧‧‧first needle board

141‧‧‧second needle board

31‧‧‧Upper knife

30‧‧‧Upper knife limiter

31‧‧‧Upper knife

40‧‧‧ Lower knife limiter

41‧‧‧Under the knife

"this invention"

112‧‧‧Card Department

20‧‧‧Upper cutter drive

21‧‧‧Active parts

22‧‧‧Drives

23‧‧‧ pivot

24‧‧‧ Connecting rod

240‧‧ ‧ chute

242‧‧‧ second end

25‧‧‧Power transmission parts

250‧‧‧Axis

31‧‧‧Upper knife

310‧‧‧Adjustment hole

311‧‧‧ adjustment bolt

32‧‧‧Upper knife holder

320‧‧‧ seat

321‧‧‧ fixed sipe

322‧‧‧ pivot

33‧‧‧Return spring

34‧‧‧Limited body

340‧‧‧ center hole

341‧‧‧ Limit slot

35‧‧‧ Limit bolt

36‧‧‧Upper cutter transmission parts

360‧‧‧ Guide

361‧‧‧Extension

362‧‧‧Parts

363‧‧‧Pivot

364‧‧‧First wearing hole

365‧‧‧

366‧‧‧Second piercing

37‧‧‧ Guides

370‧‧‧ ear

371‧‧‧First perforation

372‧‧‧Second perforation

38‧‧‧ fixing bolt

373‧‧ ‧ guide slot

42‧‧‧ Lower cutter combined with seat

43‧‧‧Adjustment

44‧‧‧ knob

45‧‧‧ Lower cutter shaft

420‧‧‧Knife Department

421‧‧‧ vertical end

422‧‧‧guide hole

423‧‧‧Let the hole

424‧‧‧Adjustment hole

425‧‧‧Restriction Department

426‧‧‧Limited

430‧‧‧With shaft hole

431‧‧‧passive teeth

434‧‧‧Adjustment Department

441‧‧‧ notch

440‧‧‧Limited

Claims (9)

A sewing machine cutting mechanism (2), the sewing machine has a transmission shaft through an upper cutter transmission device to drive the upper cutter action of the cutter limit device on the cutter mechanism, and the cutter mechanism further has a lower cutter Cooperating with the upper cutter; the upper cutter transmission device is driven by the drive shaft with a first moving end of the connecting rod, and the middle portion of the connecting rod is pivoted to a base, and the two ends are respectively respectively a first end and a second end; the upper cutter limiting device has an upper cutter, an upper cutter seat, a return spring, a limit body and a limit bolt, wherein the upper cutter is fixed to the One end of the upper cutter holder, the other end of the upper cutter holder passes through the return spring and the limiting body, and is characterized in that: the upper cutter limiting device further has an upper cutter transmission member, the upper cutting The cutter transmission member is configured to pass through the upper cutter holder, the limit bolt is mutually restrained between the upper cutter transmission member and the limiting body, the upper cutter transmission member has a guide portion; Fixed to the base, the guide member is provided with a guide slot for the guide portion of the upper cutter transmission member, and the guide portion of the upper cutter transmission member passes through the guide portion An end member on the second end of the link for the transmission of the driving cutter. A sewing machine cutting mechanism (2) according to the first aspect of the patent application, wherein the upper cutter transmission member extends from the top end of the guide portion to an extension portion, and the end portion of the extension portion is provided with abutting portion, the upper cutter transmission member a first receiving hole is formed at the connection between the extending portion and the guiding portion for the upper cutting seat to pass through, and a second receiving hole is provided at the opposite portion of the abutting portion for the upper cutting seat The end is passed through, and the upper cutting seat is sleeved with a return spring and a limiting body between the two wearing holes, and one end of the returning spring is placed on the end of the first receiving hole, and the other end is placed on the limiting body. A sewing machine cutting mechanism (2) as shown in the second aspect of the patent application, wherein a protruding edge is further disposed at a middle portion of the extending portion, and the limiting body is fixed to the upper cutting tool holder, and the upper cutting tool holder is The first and second through holes are axially moved, and the limiting body is restricted by the abutting portion and the retaining edge. A sewing machine cutting mechanism (2) according to the first aspect of the patent application, wherein the second end of the connecting rod is opposite to the end of the upper cutter driving member, and a power transmission member is pivotally connected to the power transmitting member. One end of the piece is slidably disposed in the chute. A sewing machine cutting mechanism (2), the sewing machine has a transmission shaft through a top cutter transmission device to drive a cutter mechanism on the upper cutter mechanism, and the machine base is further provided with a lower cutter The cutter limiting device cooperates with the upper cutter; the lower cutter limiting device has a lower cutter and a lower cutter combined with the lower cutter, and the characteristic is that the lower cutter is combined The seat body has an adjusting hole; an adjusting member has a threading hole, and the outer diameter of the adjusting member and the lower cutting knife combined with the adjusting hole of the seat body is an adjusting portion having an external thread; The other end of the protrusion is pivoted to the through hole of the adjusting member, and the adjusting member is rotatably adjustable to adjust the position of the lower cutting tool joint body. A sewing machine cutting mechanism (2) according to the fifth aspect of the patent application, wherein the adjusting member is provided with a tooth having a surrounding tooth shape at an end portion of the lower cutting tool joint body, and the sewing machine cutting mechanism further comprises a knob, and the knob forms a notch facing the end surface of the adjusting member, and the periphery of the notch extends a limiting portion to the lower cutter coupling body limiting portion, and the inner diameter of the recess is provided with an active surrounding shape The teeth are driven by the active teeth engaging the passive teeth of the adjusting member. The sewing machine cutting mechanism (2) shown in claim 6 is characterized in that: the limiting portion of the knob is further provided with an elastic card portion, the knob is sleeved on the passive tooth, and the card portion and the passive tooth card are stopped. Retreat. A sewing machine cutting mechanism (2) as shown in claim 7 is characterized in that the peripheral portion of the card portion is provided with a slit to form elasticity. A sewing machine cutting mechanism (2) as shown in claim 5, wherein the lower cutter shaft is provided with a receiving groove for receiving a resilient retaining ring, and the outer circumference of the retaining ring is The elastic top abuts the adjustment member.