CN113957622B

CN113957622B - Flat seaming machine

Info

Publication number: CN113957622B
Application number: CN202010703478.6A
Authority: CN
Inventors: 何明金; 祝书伟; 陈勇
Original assignee: Jack Technology Co Ltd
Current assignee: Jack Technology Co Ltd
Priority date: 2020-07-21
Filing date: 2020-07-21
Publication date: 2023-04-25
Anticipated expiration: 2040-07-21
Also published as: CN113957622A

Abstract

The utility model provides a flat seaming machine which comprises a main shaft, a tooth frame, a feeding tooth, a tooth lifting mechanism, a presser foot and presser foot lifting mechanism, a lower supply crank and a lower supply connecting rod, wherein the presser foot lifting mechanism is provided with a presser foot lifting driving source, the upper end and the lower end of the lower supply connecting rod are respectively hinged with a tooth lifting driving part in the lower supply crank and the tooth lifting mechanism, and the hinge point of the lower supply crank and the lower supply connecting rod is arranged in a dislocation way with a first fixed swinging fulcrum. In this application, lift presser foot mechanism when carrying out and lifting the presser foot action, lift presser foot mechanism and still drive and supply crank rotation down, and then make the feeding tooth descend to the upper surface of faller in the lockstitch machine under, realize that the feeding tooth can not upwards emit from the faller when lifting the presser foot, realize from this that supply down is discharged and supply down to get the material, guarantee the sewing experience. In addition, the presser foot lifting mechanism is of an existing structure in the lockstitch sewing machine, only the lower supply crank and the lower supply connecting rod extending up and down are needed to be additionally arranged, the whole machine of the lockstitch sewing machine is changed very little, and the cost is greatly reduced.

Description

Flat seaming machine

Technical Field

The utility model relates to the field of sewing machines, in particular to a flat sewing machine.

Background

The lockstitch sewing machine is provided with a presser foot lifting mechanism, a feed tooth lifting mechanism for driving the feed tooth to reciprocate up and down, a feed mechanism for driving the feed tooth to reciprocate back and forth, and the like. When in sewing, the main shaft is driven by the main motor to rotate, the main shaft drives the tooth frame and the feeding teeth to reciprocate back and forth along the horizontal direction through the feeding mechanism, and the main shaft drives the tooth frame and the feeding teeth to reciprocate up and down along the vertical direction through the lifting tooth mechanism, so that the feeding teeth do the composite motion of back and forth reciprocating motion and up and down reciprocating motion, and the motion track is similar to an ellipse. Before the start of sewing and when the end of sewing, the presser foot lifting mechanism executes automatic presser foot lifting, and the presser foot is lifted upwards.

Further, in the existing lockstitch sewing machine, the presser foot lifting mechanism generally comprises a presser foot lifting electromagnet, a right lever, a presser foot lifting pull rod, a left lever, a presser foot lifting plate, a pressure lever guide frame and a pressure lever extending up and down, wherein the presser foot lifting electromagnet is a driving source and drives the right lever to swing, two ends of the presser foot lifting pull rod are respectively connected with the right lever and the left lever, the left lever is connected with the presser foot lifting plate, the presser foot lifting plate is clamped with the pressure lever guide frame, the pressure lever guide frame is fixed on the pressure lever, and the lower end of the pressure lever is provided with a presser foot. The presser foot lifting mechanism with the structure is commonly used in a lockstitch sewing machine, for example: a sewing machine is disclosed in Chinese patent application No. 201821897744.8.

However, the lockstitch sewing machine of the above structure has the following drawbacks: when the flat seaming machine lifts the presser foot, in order to ensure that the stitching materials are normally placed under the presser foot or taken away from the presser foot, a needle in the flat seaming machine is at the highest point, and the movement of the needle is driven by a main shaft, namely, the needle and a feeding tooth are synchronously linked. When the needle is positioned above the needle plate, the feeding teeth also upwards emerge from the tooth grooves of the needle plate, at the moment, the stitching materials cannot be smoothly placed on the needle plate during discharging, and particularly for elastic thin materials, the elastic thin materials are easily hung by the feeding teeth to cause uneven placement; the sewing material is not easy to take out when the material is taken out, and whether the sewing experience is affected or not is not influenced.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present utility model is to provide a lockstitch sewing machine, in which the feeding teeth are automatically lowered when the presser foot is lifted, and the whole machine of the lockstitch sewing machine is less modified.

In order to achieve the above purpose, the utility model provides a sewing machine, which comprises a main shaft, a tooth frame, a feeding tooth arranged on the tooth frame, a tooth lifting mechanism connected between the main shaft and the tooth frame, a presser foot lifting mechanism for driving the presser foot to move upwards, a lower supply crank and a lower supply connecting rod, wherein the presser foot lifting mechanism is provided with a presser foot lifting driving source, the lower supply crank is provided with a first fixed swing fulcrum, the upper end and the lower end of the lower supply connecting rod are respectively hinged with a tooth lifting transmission part in the lower supply crank and the tooth lifting mechanism, and the hinge point of the lower supply crank and the lower supply connecting rod is arranged in a dislocation manner with the first fixed swing fulcrum;

when the presser foot lifting mechanism does not execute the presser foot lifting action, no power is transmitted between the presser foot lifting driving source and the lower supply crank;

when the presser foot lifting mechanism executes the presser foot lifting action, the presser foot lifting driving source drives the lower supply crank to rotate around the first fixed swing fulcrum, and the lower supply crank drives the lifting tooth transmission part to move through the lower supply connecting rod so that the feeding teeth descend below the upper surface of the needle plate in the lockstitch sewing machine.

Further, the presser foot lifting driving source is provided with a driving part which can extend and retract up and down;

when the presser foot lifting mechanism does not execute the presser foot lifting action, the driving part of the presser foot lifting driving source is positioned at the lower side of the lower supply crank and is not contacted with the lower supply crank;

when the presser foot lifting mechanism executes the presser foot lifting action, the driving part of the presser foot lifting driving source is abutted with the lower supply crank.

Further, the lockstitch sewing machine further comprises a supporting plate fixed on the lockstitch sewing machine shell, the lower supply crank is hinged with the supporting plate, and a hinge point of the lower supply crank and the supporting plate forms a first fixed swing fulcrum of the lower supply crank.

Further, the matching point of the presser foot lifting driving source and the lower supply crank, the hinging point of the lower supply crank and the lower supply connecting rod, and the first fixed swinging fulcrum of the lower supply crank are sequentially arranged along the extending direction of the lower supply crank

Further, the presser foot lifting mechanism further comprises a right lever with a second fixed swinging fulcrum, a presser foot lifting rod, a left lever with a third fixed swinging fulcrum, a presser foot lifting plate, a presser foot guide frame and a pressing rod extending up and down, wherein the presser foot lifting driving source is connected with one end of the right lever and drives the right lever to rotate around the second fixed swinging fulcrum, the other end of the right lever is hinged with one end of the presser foot lifting rod, the other end of the presser foot lifting rod is hinged with one end of the left lever, the other end of the left lever is hinged with the upper end of the presser foot lifting plate, a lifting hook part is arranged on the presser foot lifting plate, a connecting protruding part clamped with the lifting hook part is arranged on the presser foot guide frame, the presser foot guide frame is fixed at the upper end of the pressing rod, and the presser foot is installed at the lower end of the pressing rod.

Further, the lifting tooth mechanism comprises a lifting tooth shaft parallel to the main shaft, a first lifting tooth transmission assembly connected between the main shaft and the lifting tooth shaft, and a second lifting tooth transmission assembly connected between the lifting tooth shaft and the tooth frame, wherein the lifting tooth transmission assembly is one of the first lifting tooth transmission assemblies.

Further, the first tooth-lifting transmission assembly comprises a tooth-lifting eccentric wheel fixed on the main shaft, a tooth-lifting connecting rod, a tooth-lifting swinging seat with a fourth fixed swinging fulcrum, a first swinging plate, a second swinging plate and a tooth-lifting crank fixed on a tooth-lifting shaft, one end of the tooth-lifting connecting rod is rotatably sleeved on the periphery of the tooth-lifting eccentric wheel, the other end of the tooth-lifting connecting rod, one end of the first swinging plate and one end of the second swinging plate are coaxially hinged, the other end of the first swinging plate is hinged with the tooth-lifting swinging seat, the other end of the second swinging plate is hinged with the tooth-lifting crank, and the tooth-lifting swinging seat is hinged with the lower connecting rod.

Further, the lockstitch sewing machine also comprises a stitch length adjusting mechanism, wherein the stitch length adjusting mechanism acts on the lifting tooth swinging seat and is used for changing the position angle of the lifting tooth swinging seat.

Further, the stitch length adjusting mechanism comprises an adjusting stud in the sewing machine shell in threaded connection, an adjusting knob fixed at the outer end of the adjusting stud, an adjusting crank rotatably installed in the sewing machine shell and provided with a fifth fixed swinging fulcrum, and an adjusting connecting rod, wherein the inner end of the adjusting stud is abutted to the adjusting crank and drives the adjusting crank to rotate around the fifth fixed swinging fulcrum, and two ends of the adjusting connecting rod are hinged with the adjusting crank and the lifting tooth swinging seat respectively.

Further, the second lifting tooth transmission assembly comprises a lifting tooth fork fixed on the lifting tooth shaft and a lifting tooth sliding block hinged with the tooth frame, a lifting tooth sliding groove is formed in the lifting tooth fork, and the lifting tooth sliding block is located in the lifting tooth sliding groove and is in sliding fit with the lifting tooth sliding groove.

As described above, the flush joint machine according to the present utility model has the following advantages:

in this application, lift presser foot mechanism when carrying out and lifting the presser foot action, lift presser foot mechanism and still drive and supply crank rotation down, and then make the feeding tooth descend to the upper surface of faller in the lockstitch machine under, realize that the feeding tooth can not upwards emit from the faller when lifting the presser foot, realize from this that supply down is discharged and supply down to get the material, guarantee the sewing experience. In addition, the presser foot lifting mechanism is of an existing structure in the lockstitch sewing machine, only the lower supply crank and the lower supply connecting rod extending up and down are needed to be additionally arranged, the whole machine of the lockstitch sewing machine is changed very little, and the cost is greatly reduced.

Drawings

Fig. 1 is a schematic structural view of a flat seaming machine according to the present application.

Fig. 2 is an enlarged view of circle a of fig. 1.

Fig. 3 is a schematic diagram of the connection among the presser foot lifting mechanism, the lower crank, the lower connecting rod and the lifter swing seat in the present application.

Fig. 4 is a schematic diagram of connection between the needle pitch adjusting mechanism and the lifting tooth swinging seat in the present application.

Fig. 5 is a diagram showing a relationship between the presser foot lifting drive source and the lower feed crank when the presser foot lifting mechanism does not perform the presser foot lifting operation in the present application.

Fig. 6 is a view showing the positional relationship between the feed dog, presser foot and needle plate in the state of fig. 5.

Fig. 7 is a diagram showing a relationship between a presser foot lifting drive source and a lower feed crank when the presser foot lifting mechanism performs a presser foot lifting operation in the present application.

Fig. 8 is a view showing the positional relationship between the feed dog, presser foot and needle plate in the state of fig. 7.

Description of element reference numerals

10. Main shaft

20. Tooth rack

30. Feeding tooth

40. Tooth lifting mechanism

41. Lifting shaft

42. Lifting tooth eccentric wheel

43. Lifting tooth connecting rod

44. Lifting tooth swinging seat

441. Left seat arm

442. Right seat arm

45. First swinging plate

46. Second swinging plate

47. Lifting tooth crank

48. Feed lifting fork

49. Lifting tooth sliding block

410. Supporting pin

50. Presser foot

60. Presser foot lifting mechanism

61. Presser foot lifting driving source

611. Drive unit

62. Right lever

63. Presser foot lifting pull rod

64. Left lever

65. Lifting plate for lifting presser foot

66. Compression bar guide frame

67. Compression bar

70. Lower supply crank

80. Lower supply connecting rod

90. Supporting plate

110. Needle pitch adjusting mechanism

111. Adjusting stud

112. Adjusting knob

113. Adjusting crank

114. Adjusting connecting rod

115. Supporting shaft

116. Tension spring

117. Pulling plate

120. Needle plate

Detailed Description

Further advantages and effects of the present utility model will become apparent to those skilled in the art from the disclosure of the present utility model, which is described by the following specific examples.

It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the utility model to the extent that it can be practiced, since modifications, changes in the proportions, or adjustments of the sizes, which are otherwise, used in the practice of the utility model, are included in the spirit and scope of the utility model which is otherwise, without departing from the spirit or scope thereof. Also, the terms such as "upper," "lower," "left," "right," "middle," and "a" and the like are used herein for descriptive purposes only and not for purposes of limitation, and are intended to limit the scope of the utility model as defined by the claims and the relative terms thereof as construed as corresponding to the claims.

As shown in fig. 1, the present application provides a lockstitch sewing machine having a housing, a main shaft 10 rotatably mounted in the housing, and a main motor for driving the main shaft 10 to rotate. For convenience of description, in the following embodiments, the following directions are defined as follows: defining the axial direction of the main shaft 10 as the left-right direction, the direction of the main shaft 10 facing the head of the flat seaming machine as the left direction, and the direction of the main shaft 10 facing the tail of the flat seaming machine as the right direction; defining the moving direction of the sewing material as the front direction when the flat seaming machine is forward seaming; a direction orthogonal to both the left-right direction and the front-rear direction is defined as an up-down direction.

Further, as shown in fig. 1 and 3, the lockstitch sewing machine according to the present application further includes a feed gear 30 fixedly mounted on the feed gear 20, a feed gear 40 connected between the spindle 10 and the rear end of the feed gear 20, a presser foot 50, a presser foot lifting mechanism 60 for driving the presser foot 50 to move upward, a lower feed crank 70, and a lower feed link 80, wherein the presser foot lifting mechanism 60 has a presser foot lifting driving source 61, the lower feed crank 70 has a first fixed swing pivot O1, the upper end of the lower feed link 80 is hinged with the lower feed crank 70 by a left-right extending axial screw, and the hinge point of the lower feed crank 70 and the lower feed link 80 is set in a dislocation manner with the first fixed swing pivot O1 of the lower feed crank 70, and the lower end of the lower feed link 80 is hinged with a lifter transmission member in the feed gear 40 by a left-right extending axial screw.

In the lockstitch sewing machine, when the presser foot lifting mechanism 60 does not perform the presser foot lifting operation, as shown in fig. 5, no power is transmitted between the presser foot lifting driving source 61 and the lower feed crank 70; at this time, the presser foot lifting driving source 61 does not act, the lower feed crank 70 maintains the current position angle, and further, the lower feed link 80 and the lifter transmission member in the lifter mechanism 40 maintain the current position angle, when the main motor drives the main shaft 10 to rotate, the main shaft 10 drives the rack 20 and the feed dog 30 to reciprocate up and down through the lifter mechanism 40, and the feed dog 30 stably performs the lifter action, as shown in fig. 6, the feed dog 30 may protrude upward from the needle plate 120 of the lockstitch machine. When the presser foot lifting mechanism 60 performs the presser foot lifting operation, the presser foot lifting driving source 61 is operated, and the presser foot lifting mechanism 60 drives the presser foot 50 to lift up; meanwhile, power is transmitted between the presser foot lifting driving source 61 and the lower feed crank 70, as shown in fig. 7, that is, the lower feed crank 70 is driven by the presser foot lifting driving source 61 to rotate around the first fixed swing pivot O1, and then the lower feed crank 70 drives the feed dog transmission member to move through the lower feed link 80, so that the feed dog 30 descends below the upper surface of the needle plate 120 in the lockstitch sewing machine, as shown in fig. 8.

As can be seen from the above description, the lockstitch machine according to the present application further performs the feeding operation of lowering the feeding tooth 30 below the needle plate 120 when performing the presser foot lifting operation, so that the feeding tooth 30 does not protrude upward from the needle plate 120 even when the presser foot 50 is lifted upward and the needle in the lockstitch machine moves to the highest point, thereby realizing feeding and discharging, improving the sewing experience of the user, and improving the product competitiveness. In addition, the presser foot lifting mechanism 60 in the present application is an existing structure in the lockstitch sewing machine, and only the lower supply crank 70 and the lower supply connecting rod 80 extending up and down are required to be additionally arranged, so that the whole machine of the lockstitch sewing machine is changed very little, and the cost is greatly reduced.

Preferably, as shown in fig. 3, the lockstitch machine further includes a support plate 90 fixed to the housing of the lockstitch machine, the lower support crank 70 is hinged to the support plate 90 by a left-right extending axial screw, and the hinge point of the lower support crank 70 and the support plate 90 forms a first fixed swing fulcrum O1 of the lower support crank 70. In addition, the lower feed crank 70 extends in the front-rear direction, and the mating point of the presser foot lifting drive source 61 and the lower feed crank 70, the hinge point of the lower feed crank 70 and the lower feed link 80, and the first fixed swing fulcrum O1 of the lower feed crank 70 are sequentially arranged from front to rear, and the mating point of the presser foot lifting drive source 61 and the lower feed crank 70 is located at the front end of the lower feed crank 70.

Further, the presser foot lifting driving source 61 has a driving part 611 that can be extended and contracted up and down, and based on this, the presser foot lifting driving source 61 may be an electromagnet, a cylinder, a linear motor, or the like, and in this embodiment, the presser foot lifting driving source 61 is an electromagnet, and the iron core of the electromagnet forms the driving part 611. When the presser foot lifting mechanism 60 does not perform the presser foot lifting operation, as shown in fig. 5, the driving portion 611 of the presser foot lifting driving source 61 is positioned below the lower feed crank 70 so that the both do not contact each other. When the presser foot lifting mechanism 60 performs the presser foot lifting operation, as shown in fig. 7, the driving portion 611 of the presser foot lifting driving source 61 abuts against the lower end surface of the lower feed crank 70, and when the driving portion 611 of the presser foot lifting driving source 61 moves upward, the presser foot 50 is driven by the remaining components in the presser foot lifting mechanism 60 to lift up and perform the presser foot lifting operation, and at the same time, the lower feed crank 70 is driven to rotate about the first fixed swing fulcrum O1 thereof by abutment between the driving portion 611 and the front end of the lower feed crank 70 to perform the lower feed operation.

Further, the preferable structure of the presser foot lifting mechanism 60 is: as shown in fig. 3, the presser foot lifting transmission assembly includes a right lever 62 having a second fixed swing fulcrum O2, a presser foot lifting lever 63, a left lever 64 having a third fixed swing fulcrum O3, a presser foot lifting plate 65, a presser bar guide 66, and a vertically extending presser bar 67; the right lever 62 and the left lever 64 are hinged to the machine shell of the lockstitch sewing machine through a shaft position screw extending forwards and backwards; the right upper end of the right lever 62 is hinged with a driving part 611 of the presser foot lifting driving source 61, and the left lower end of the right lever 62 is hinged with the right end of the presser foot lifting pull rod 63; the left end of the presser foot lifting pull rod 63 is hinged with the right upper end of the left lever 64; the left lower end of the left lever 64 is hinged with the upper end of the presser foot lifting plate 65; the presser foot lifting plate 65 is provided with a lifting hook part, and the pressure bar guide frame 66 is provided with a connecting protruding part which is clamped with the lifting hook part; the compression bar guide 66 is fixed at the upper end of the compression bar 67; the presser foot 50 is mounted at the lower end of the presser bar 67. When the driving part 611 of the presser foot lifting driving source 61 extends upwards, the presser foot lifting driving source 61 drives the right lever 62 to rotate clockwise around the second fixed swinging fulcrum O2, the right lever 62 drives the left lever 64 to rotate anticlockwise around the third fixed swinging fulcrum O3 through the presser foot lifting pull rod 63, and then the presser foot lifting plate 65 is driven to move upwards, so that the presser bar 67 is driven to move upwards through the presser bar guide frame 66, finally the presser foot 50 is driven to move upwards, and the presser foot lifting action is executed.

Further, the preferred structure of the tooth lifting mechanism 40 is: as shown in fig. 1, the lifting tooth mechanism 40 includes a lifting tooth shaft 41 parallel to the main shaft 10, a first lifting tooth transmission assembly connected between the main shaft 10 and the right end of the lifting tooth shaft 41, and a second lifting tooth transmission assembly connected between the left end of the lifting tooth shaft 41 and the rear end of the tooth frame 20, and the lifting tooth transmission assembly is one of the first lifting tooth transmission assemblies.

Further, as shown in fig. 1 and 2, the first lifting-tooth transmission assembly includes a lifting-tooth eccentric wheel 42, a lifting-tooth connecting rod 43, a lifting-tooth swinging seat 44 with a fourth fixed swinging fulcrum O4, a first swinging plate 45, a second swinging plate 46, and a lifting-tooth crank 47 locked at the right end of the lifting-tooth shaft 41 by screw fixation, wherein the upper end of the lifting-tooth connecting rod 43 is rotatably sleeved on the outer periphery of the upper eccentric part of the lifting-tooth eccentric wheel 42, the lower end of the lifting-tooth connecting rod 43, one end of the first swinging plate 45 and one end of the second swinging plate 46 are coaxially hinged by a pin extending from left to right, the other end of the first swinging plate 45 is hinged with the lifting-tooth swinging seat 44 by a pin extending from left to right, and the other end of the second swinging plate 46 is hinged with the lifting-tooth crank 47 by a pin extending from left to right. The lifting-tooth swinging seat 44 constitutes the lifting-tooth transmission part, and the lifting-tooth swinging seat 44 is hinged with the lower supply connecting rod 80 through a left-right extending axial screw. As shown in fig. 1, the second tooth lifting transmission assembly comprises a tooth lifting fork 48 fixed on the tooth lifting shaft 41 and a tooth lifting sliding block 49, a tooth lifting sliding groove is formed in the tooth lifting fork 48, the tooth lifting sliding block 49 is located in the tooth lifting sliding groove and is in sliding fit with the tooth lifting sliding groove, and the tooth lifting sliding block 49 is hinged with the tooth rack 20 through a pin extending from left to right.

Preferably, as shown in fig. 2, the lifting-tooth swinging seat 44 has two seat arm portions symmetrically arranged left and right, and the two seat arm portions are respectively a left seat arm portion 441 and a right seat arm portion 442; the first swinging plates 45 and the second swinging plates 46 are respectively arranged between the left seat arm portion 441 and the right seat arm portion 442, the two second swinging plates 46 are distributed on the left side and the right side of the lower end of the tooth lifting connecting rod 43, and the first swinging plates 45 are respectively distributed between the first swinging plates 45 and the left seat arm portion 441 and between the first swinging plates 45 and the right seat arm portion 442. The left seat arm 441 and the right seat arm 442 are rotatably mounted on a support pin 410 extending in the left-right direction, the support pin 410 is fixed to the sewing machine casing, and constitutes a fourth fixed swing fulcrum O4 of the lift arm 44, and the lift arm 44 is rotatable about the support pin 410.

Further, as shown in fig. 1, the lockstitch sewing machine further includes a stitch length adjusting mechanism 110; when the stitch length adjusting mechanism 110 acts, the stitch length adjusting mechanism 110 acts on the feed lifting and swinging seat 44 to drive the feed lifting and swinging seat 44 to rotate around the supporting pin 410 by an angle, so that the position angle of the feed lifting and swinging seat 44 is changed, the transmission efficiency of the feed lifting and swinging mechanism 40 in the follow-up sewing process is changed, and the adjustment of the feed lifting and swinging height of the feed feeding tooth 30 is realized.

Further, the preferred structure of the stitch length adjusting mechanism 110 is: as shown in fig. 4, the stitch length adjusting mechanism 110 includes an adjusting stud 111 extending forward and backward, an adjusting knob 112 fixed at the rear end of the adjusting stud 111, an adjusting crank 113 rotatably installed in the sewing machine housing and having a fifth fixed swing fulcrum O5, and an adjusting link 114, the adjusting stud 111 is screwed in the sewing machine housing, the front end of the adjusting stud 111 abuts against the adjusting crank 113, and the contact point of the adjusting stud 111 and the fifth fixed swing fulcrum O5 of the adjusting crank 113 are dislocated, and the upper and lower ends of the adjusting link 114 are hinged with the adjusting crank 113 and the lifting-tooth swing seat 44 respectively through a pin extending left and right. When the adjusting knob 112 is rotated, the adjusting knob 112 drives the adjusting stud 111 to rotate together, the adjusting stud 111 moves forward or right while rotating, and then the adjusting crank 113 is driven to rotate around the fifth fixed swinging fulcrum O5, and the adjusting crank 113 acts on the lifting-tooth swinging seat 44 through the adjusting connecting rod 114 and drives the lifting-tooth swinging seat 44 to rotate around the supporting pin 410 by an angle.

Preferably, the adjusting crank 113 is rotatably mounted on a support shaft 115 extending in the left-right direction, the support shaft 115 is fixed to the lockstitch machine casing and constitutes a fifth fixed swing fulcrum O5 of the adjusting crank 113, and the adjusting crank 113 is rotatable about the support shaft 115. The stitch length adjusting mechanism 110 further comprises a tension spring 116 and a pulling plate 117 fixed on the lifting tooth swinging seat 44, wherein two ends of the tension spring 116 are respectively connected with the supporting shaft 115 and the pulling plate 117; when the adjusting knob 112 does not rotate, the adjusting stud 111 is stationary relative to the sewing machine casing, the adjusting crank 113 always keeps a state of abutting against the front end of the adjusting stud 111 under the action of the tension force of the tension spring 116, and the lifting and swinging seat 44 also keeps the current position angle.

In summary, the present utility model effectively overcomes the disadvantages of the prior art and has high industrial utility value.

The above embodiments are merely illustrative of the principles of the present utility model and its effectiveness, and are not intended to limit the utility model. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the utility model. Accordingly, it is intended that all equivalent modifications and variations of the utility model be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims

1. The utility model provides a flush joint machine, includes main shaft (10), tooth frame (20), installs feeding tooth (30) on tooth frame (20), connects lift tooth mechanism (40) between main shaft (10) and tooth frame (20), presser foot (50), and drive presser foot (50) upwards remove lift presser foot mechanism (60), lift presser foot mechanism (60) have and lift presser foot actuating source (61), its characterized in that: the automatic lifting foot pressing device is characterized by further comprising a lower supply crank (70) and a lower supply connecting rod (80), wherein the lower supply crank (70) is provided with a first fixed swing pivot O1, the upper end and the lower end of the lower supply connecting rod (80) are respectively hinged with a lifting tooth transmission part in the lower supply crank (70) and the lifting tooth mechanism (40), the hinge point of the lower supply crank (70) and the lower supply connecting rod (80) is arranged in a staggered manner with the first fixed swing pivot O1, and the lifting foot pressing driving source (61) is provided with a driving part (611) which can stretch up and down;

when the presser foot lifting mechanism (60) does not execute the presser foot lifting action, a driving part (611) of the presser foot lifting driving source (61) is positioned at the lower side of the lower supply crank (70) and is not contacted with the lower supply crank (70), so that no power is transmitted between the presser foot lifting driving source (61) and the lower supply crank (70);

when the presser foot lifting mechanism (60) executes the presser foot lifting action, a driving part (611) of the presser foot lifting driving source (61) is in contact with a lower supply crank (70), the lower supply crank (70) is driven by the presser foot lifting driving source (61) to rotate around a first fixed swinging fulcrum O1, and the lower supply crank (70) drives a lifting tooth transmission part to move through a lower supply connecting rod (80) so as to enable a feeding tooth (30) to descend below the upper surface of a needle plate (120) in the lockstitch sewing machine.

2. The flush joint machine according to claim 1, wherein: the lower support crank (70) is hinged with the support plate (90), and a hinge point of the lower support crank (70) and the support plate (90) forms a first fixed swing fulcrum O1 of the lower support crank (70).

3. The flush joint machine according to claim 2, wherein: the fit point of the presser foot lifting driving source (61) and the lower supply crank (70), the hinge point of the lower supply crank (70) and the lower supply connecting rod (80) and the first fixed swinging fulcrum O1 of the lower supply crank (70) are sequentially arranged along the extending direction of the lower supply crank (70).

4. The flush joint machine according to claim 1, wherein: the presser foot lifting mechanism (60) further comprises a right lever (62) with a second fixed swinging fulcrum O2, a presser foot lifting pull rod (63), a left lever (64) with a third fixed swinging fulcrum O3, a presser foot lifting plate (65), a pressing rod guide frame (66) and a pressing rod (67) extending up and down, the presser foot lifting driving source (61) is connected with one end of the right lever (62) and drives the right lever (62) to rotate around the second fixed swinging fulcrum O2, the other end of the right lever (62) is hinged with one end of the presser foot lifting pull rod (63), the other end of the presser foot lifting pull rod (63) is hinged with one end of the left lever (64), the other end of the left lever (64) is hinged with the upper end of the presser foot lifting plate (65), a lifting hook portion is arranged on the presser foot lifting plate (65), a connecting protrusion portion clamped with the lifting hook portion is arranged on the pressing rod guide frame (66), the pressing rod guide frame (66) is fixed at the upper end of the pressing rod (67), and the pressing foot (50) is mounted at the lower end of the pressing rod (67).

5. The flush joint machine according to claim 1, wherein: the lifting tooth mechanism (40) comprises a lifting tooth shaft (41) parallel to the main shaft (10), a first lifting tooth transmission assembly connected between the main shaft (10) and the lifting tooth shaft (41), and a second lifting tooth transmission assembly connected between the lifting tooth shaft (41) and the tooth frame (20), wherein the lifting tooth transmission assembly is one of the first lifting tooth transmission assemblies.

6. The flush joint machine according to claim 5, wherein: the first lifting tooth transmission assembly comprises a lifting tooth eccentric wheel (42) fixed on a main shaft (10), a lifting tooth connecting rod (43), a lifting tooth swinging seat (44) with a fourth fixed swinging fulcrum O4, a first swinging plate (45), a second swinging plate (46) and a lifting tooth crank (47) fixed on a lifting tooth shaft (41), one end of the lifting tooth connecting rod (43) is rotatably sleeved on the periphery of the lifting tooth eccentric wheel (42), the other end of the lifting tooth connecting rod (43), one end of the first swinging plate (45) and one end of the second swinging plate (46) are coaxially hinged, the other end of the first swinging plate (45) is hinged with the lifting tooth swinging seat (44), the other end of the second swinging plate (46) is hinged with the lifting tooth crank (47), and the lifting tooth swinging seat (44) is hinged with a lower supply connecting rod (80).

7. The flush joint machine according to claim 6, wherein: the needle distance adjusting mechanism (110) acts on the lifting tooth swinging seat (44) and is used for changing the position angle of the lifting tooth swinging seat (44).

8. The flush joint machine according to claim 7, wherein: the stitch length adjusting mechanism (110) comprises an adjusting stud (111) in the flat seaming machine shell in a threaded mode, an adjusting knob (112) fixed at the outer end of the adjusting stud (111), an adjusting crank (113) rotatably installed in the flat seaming machine shell and provided with a fifth fixed swing pivot O5, and an adjusting connecting rod (114), wherein the inner end of the adjusting stud (111) is abutted to the adjusting crank (113) and drives the adjusting crank (113) to rotate around the fifth fixed swing pivot O5, and two ends of the adjusting connecting rod (114) are hinged to the adjusting crank (113) and the lifting-tooth swing seat (44) respectively.

9. The flush joint machine according to claim 5, wherein: the second lifting tooth transmission assembly comprises a lifting tooth fork (48) fixed on a lifting tooth shaft (41) and a lifting tooth sliding block (49) hinged with the tooth frame (20), a lifting tooth sliding groove is formed in the lifting tooth fork (48), and the lifting tooth sliding block (49) is located in the lifting tooth sliding groove and is in sliding fit with the lifting tooth sliding groove.