CN211394888U

CN211394888U - Thread cutting mechanism of platform type sewing machine

Info

Publication number: CN211394888U
Application number: CN201922501903.9U
Authority: CN
Inventors: 罗一明; 叶剑立
Original assignee: Precious Science And Technology Group Corp ltd
Current assignee: Precious Science And Technology Group Corp ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-09-01
Anticipated expiration: 2029-12-31

Abstract

The utility model provides a platform formula sewing machine's thread trimming mechanism belongs to sewing machine technical field. The thread cutting mechanism solves the technical problems that a thread cutting mechanism in the existing sewing machine is complex, high in manufacturing cost and the like. The thread trimming mechanism of the platform type sewing machine comprises a knife rest, a fixed knife fixed on the knife rest and a movable knife capable of trimming threads by matching with the fixed knife, wherein the movable knife is connected with a movable knife driving assembly; the movable cutter driving assembly comprises a transmission lever, a driving piece, a trimming driving gear and a movable cutter driving gear, wherein the driving piece can drive the transmission lever to move, one end of the transmission lever is connected with a trimming gear shaft, the trimming driving gear is fixed on the trimming gear shaft, a movable cutter shaft is inserted on a cutter rest, one end of the movable cutter shaft is fixedly connected with the rear end of the movable cutter, the movable cutter driving gear is fixed on the movable cutter shaft, and the movable cutter driving gear is meshed with the trimming driving gear. The utility model discloses in simplified thread trimming mechanism, had the advantage that reduces thread trimming mechanism manufacturing cost.

Description

Thread cutting mechanism of platform type sewing machine

Technical Field

The utility model belongs to the technical field of sewing machine, a platform formula sewing machine's thread trimming mechanism is related to.

Background

The sewing machine is a machine which uses one or more sewing threads to form one or more stitches on a sewing material so as to interweave or sew one or more layers of the sewing material; with the development of society, the existing sewing machine is provided with an automatic thread trimming mechanism, so that the sewing machine is more convenient to use, but the thread trimming mechanism of a plurality of sewing machines is more complex, the manufacturing cost is increased, and the maintenance is more troublesome.

Chinese patent (publication number: CN 106894175A; publication date: 2017-06-27) discloses an automatic thread trimming mechanism of a sewing machine, which comprises a lower shaft, a thread trimming driving cam fixed on the lower shaft, a movable cutter assembly capable of swinging around the lower shaft and provided with at least one movable cutter and one movable cutter holder, a crankshaft, a thread trimming driving assembly arranged at one end of the crankshaft, a thread trimming crank fixed at the other end of the crankshaft, and a thread trimming connecting rod, wherein the thread trimming driving assembly is provided with a first extension arm, the end part of the first extension arm is connected with a roller, two ends of the thread trimming connecting rod are respectively hinged with the thread trimming crank and the movable cutter holder, the distance L1 between the hinged points of the crankshaft and the thread trimming crank and the thread trimming connecting rod, the ratio of the distance L2 between the lower shaft and the hinged points of the movable cutter holder and the thread trimming connecting rod is not less than 2.5, and the transmission angle gamma of the thread trimming connecting rod to the.

The automatic thread trimming mechanism of the sewing machine disclosed in the above patent document has a complicated structure, many parts, and a high manufacturing cost.

Disclosure of Invention

The utility model discloses to the above-mentioned problem that prior art exists, provide a platform formula sewing machine's thread trimming mechanism, the utility model aims to solve the technical problem that: how to simplify the thread trimming mechanism and reduce the manufacturing cost.

The purpose of the utility model can be realized by the following technical proposal:

a thread trimming mechanism of a platform type sewing machine comprises a knife rest, a fixed knife fixed on the knife rest and a movable knife capable of being matched with the fixed knife to form shearing motion, wherein the movable knife is connected with a movable knife driving assembly; the movable knife driving assembly is characterized by comprising a transmission lever, a driving piece capable of driving the transmission lever to move, a trimming driving gear and a movable knife driving gear, wherein one end of the transmission lever is connected with a trimming gear shaft, the trimming driving gear is fixed on the trimming gear shaft, a movable knife shaft is inserted into a knife rest, one end of the movable knife shaft is fixedly connected with the rear end of the movable knife, the movable knife driving gear is fixed on the movable knife shaft, and the movable knife driving gear is meshed with the trimming driving gear.

The working principle is as follows: the driving piece in the technical scheme can drive the transmission lever to move along the length direction of the transmission lever, the transmission lever moves to drive the trimming gear shaft to rotate and further drive the trimming drive gear to rotate, and the movable cutter drive gear rotates to drive the movable cutter shaft to rotate due to the fact that the movable cutter drive gear is meshed with the trimming drive gear, so that the movable cutter swings and is matched with the fixed cutter to trim wires.

In foretell platform formula sewing machine's thread trimming mechanism, the both ends of transmission lever are connected with transmission crank and thread trimming crank respectively, transmission crank and thread trimming crank all with the transmission lever is articulated mutually, transmission crank's one end is rotated and is connected on sewing machine's casing, the thread trimming crank is fixed the one end of thread trimming gear shaft, thread trimming drive gear is located the other end of thread trimming gear shaft. The transmission lever moves along the length direction of the transmission lever, so that the transmission crank can swing around a hinge point with the machine shell, and the arrangement of the transmission crank provides favorable conditions for the swing of the movable knife.

In foretell platform formula sewing machine's thread trimming mechanism, be close to on the transmission lever transmission crank's position has the extension portion of outside extension, the extension portion orientation one side bending type of transmission lever, transmission crank with the driving piece sets up respectively the both sides of extension portion, the driving piece with extension portion meets. The driving piece and the transmission crank are in different spaces, so that the driving piece is convenient to install, and the transmission crank is convenient to move.

In the thread trimming mechanism of the platform type sewing machine, one side of the extension part, which is close to the driving part, is provided with an arc surface, the arc surface extends to the end part of the extension part from the middle part of the extension part, and the driving part is abutted against the arc surface. When the transmission lever moves along the length direction of the transmission lever, the transmission crank and the trimming crank are arranged to swing, and the position, which is contacted with the driving piece, on the extension part is an arc surface, so that the driving piece is not damaged on the contact surface with the extension part in the operation process, and the service life of the transmission lever is prolonged.

In the thread trimming mechanism of the platform type sewing machine, the driving piece is an electromagnet or an air cylinder. The armature at the end of the electromagnet or the piston end of the cylinder is abutted against the extension part to drive the transmission lever to move, the transmission crank is connected with a reset spring which can reset the transmission crank, and the transmission crank can reset to drive the transmission lever to reset.

Alternatively, the driving part is an electromagnet or an air cylinder, an armature at the end part of the electromagnet or the end part of a piston rod of the air cylinder can be fixedly connected with the extension part, and the transmission lever can be reset without a reset spring.

In foretell platform formula sewing machine's thread trimming mechanism, the thread trimming crank has the open slot, the thread trimming gear shaft is worn to establish and is locked in the open slot and through set screw, the thread trimming gear shaft with move the parallel interval of cutter shaft and set up, thread trimming crank's periphery one side has outside convex connecting portion, the connecting axle has set firmly on the connecting portion, the transmission lever passes through the connecting axle with the thread trimming crank is articulated mutually. The thread trimming crank can be detached or installed by loosening or locking the fixing screw, and time is saved during maintenance.

Compared with the prior art, the utility model provides a trimming mechanism simple structure, spare part is few, makes current trimming mechanism obtain simplifying, has the advantage that reduces trimming mechanism manufacturing cost.

Drawings

Fig. 1 is a schematic perspective view of a thread trimming mechanism of the flat bed sewing machine.

Fig. 2 is a schematic perspective view of a thread trimming mechanism of the flat bed sewing machine.

Fig. 3 is a three-dimensional structure schematic diagram of the thread trimming mechanism of the platform type sewing machine.

In the figure, 1, a tool holder; 2. fixing a cutter; 3. moving a knife; 4. a moving blade driving component; 41. a transmission lever; 41a, an extension part; 41a1, arc surface; 42. a drive member; 43. a thread cutting driving gear; 44. the moving blade drives the gear; 45. a trimming gear shaft; 46. a movable cutter shaft; 47. a drive crank; 48. a thread cutting crank; 48a, an open slot; 48b, a connecting part; 5. a set screw; 6. and (7) connecting the shafts.

Detailed Description

The following are specific embodiments of the present invention and the accompanying drawings are used to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

As shown in fig. 1 to 3, the thread trimming mechanism of the platform-type sewing machine in this embodiment includes a knife rest 1, a stationary knife 2 and a movable knife 3 capable of cooperating with the stationary knife 2 to form a trimming motion are fixedly disposed on the knife rest 1, the movable knife 3 is connected to a movable knife driving assembly 4 capable of driving the movable knife 3 to swing, the movable knife driving assembly 4 includes a transmission lever 41, a driving member 42, a trimming gear shaft 45, a trimming driving gear 43 and a movable knife driving gear 44, a movable knife shaft 46 is inserted on the knife rest 1, a rear end of the movable knife 3 is fixedly connected to one end of the movable knife shaft 46, the movable knife driving gear 44 is fixed to the movable knife shaft 46 near the other end, the movable knife shaft 46 and the trimming gear shaft 45 are disposed in parallel and spaced relation, a trimming crank 48 is fixedly disposed at one end of the trimming gear shaft 45, the trimming crank 48 has an open slot 48a, the trimming gear shaft 45 is inserted into the open slot 48a and is locked by, one side of the periphery of the thread cutting crank 48 is provided with a connecting part 48b protruding outwards, a connecting shaft 6 is fixedly arranged in the connecting part 48b, one end of a transmission lever 41 is hinged with the thread cutting crank 48 through the connecting shaft 6, a thread cutting driving gear 43 is fixedly arranged at the other end of a thread cutting gear shaft 45, the thread cutting driving gear 43 is meshed with a movable knife driving gear 44, the other end of the transmission lever 41 is connected with a transmission crank 47, one end of the transmission crank 47 is hinged with the sewing machine shell, the transmission lever 41 is hinged with the transmission crank 47, the hinged point of the transmission lever 41 and the transmission crank 47 is a position on the transmission crank 47 close to the other end, an extending part 41a extending outwards is arranged on the position on the transmission lever 41 close to the transmission crank 47, the extending part 41a bends towards one side of the transmission lever 41, the transmission crank 47 and a driving part 42 are arranged on two sides of the extending part 41a, the driving part 42 is connected, the transmission lever 41 drives the thread trimming crank 48 to swing, the thread trimming gear shaft 45 rotates to drive the thread trimming driving gear 43 to rotate, the movable cutter driving gear 44 rotates to drive the movable cutter 3 to swing, and the movable cutter 3 and the fixed cutter 2 are matched for thread trimming.

Further, as shown in fig. 2, the driving element 42 is an electromagnet or an air cylinder, one side of the extending portion 41a close to the driving element 42 is provided with an arc surface 41a1, the arc surface 41a1 extends from the middle of the extending portion 41a to the end of the extending portion 41a, an armature at the end of the electromagnet or the end of a piston rod of the air cylinder abuts against the arc surface 41a1 of the extending portion 41a, the driving crank 47 is connected with a return spring, and the driving crank 47 is returned to drive the driving lever 41 to return; the armature at the end of the magnet or the end of the piston rod of the cylinder may also be fixedly connected to the extension 41a, and when the armature at the end of the magnet or the piston rod of the cylinder is reset, the transmission lever 41 is reset accordingly.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims

1. A thread trimming mechanism of a platform type sewing machine comprises a knife rest (1), a fixed knife (2) fixed on the knife rest (1) and a movable knife (3) capable of being matched with the fixed knife (2) to form shearing motion, wherein the movable knife (3) is connected with a movable knife driving assembly (4); the movable knife driving assembly is characterized in that the movable knife driving assembly (4) comprises a transmission lever (41), and can drive a driving piece (42), a trimming driving gear (43) and a movable knife driving gear (44) which are moved by the transmission lever (41), one end of the transmission lever (41) is connected with a trimming gear shaft (45), the trimming driving gear (43) is fixed on the trimming gear shaft (45), a movable knife shaft (46) is inserted on the knife rest (1), one end of the movable knife shaft (46) is fixedly connected with the rear end of the movable knife (3), the movable knife driving gear (44) is fixed on the movable knife shaft (46), and the movable knife driving gear (44) is meshed with the trimming driving gear (43).

2. The thread trimming mechanism of a flatbed sewing machine according to claim 1, wherein both ends of the transmission lever (41) are respectively connected with a transmission crank (47) and a thread trimming crank (48), the transmission crank (47) and the thread trimming crank (48) are hinged with the transmission lever (41), one end of the transmission crank (47) is rotatably connected to a machine shell of the sewing machine, the thread trimming crank (48) is fixed at one end of the thread trimming gear shaft (45), and the thread trimming driving gear (43) is located at the other end of the thread trimming gear shaft (45).

3. The thread trimming mechanism of a flatbed sewing machine according to claim 2, wherein the transmission lever (41) has an extension (41a) extending outward at a position close to the transmission crank (47), the extension (41a) is bent toward one side of the transmission lever (41), the transmission crank (47) and the driving member (42) are respectively disposed at both sides of the extension (41a), and the driving member (42) is connected to the extension (41 a).

4. The thread trimming mechanism of a flatbed sewing machine according to claim 3, wherein the extension portion (41a) has a circular arc surface (41a1) on a side thereof adjacent to the driving member (42), the circular arc surface (41a1) extends from a middle portion of the extension portion (41a) to an end portion of the extension portion (41a), and the driving member (42) abuts against the circular arc surface (41a 1).

5. The thread trimming mechanism of a flatbed sewing machine as claimed in claim 1, 2, 3 or 4, wherein the driving member (42) is an electromagnet or an air cylinder.

6. The trimming mechanism of a platform type sewing machine according to claim 2, wherein the trimming crank (48) is provided with an open slot (48a), the trimming gear shaft (45) is arranged in the open slot (48a) in a penetrating manner and locked by a fixing screw (5), the trimming gear shaft (45) and the movable cutter shaft (46) are arranged in parallel at intervals, one side of the periphery of the trimming crank (48) is provided with a connecting part (48b) protruding outwards, the connecting part (48b) is fixedly provided with a connecting shaft (6), and the transmission lever (41) is hinged with the trimming crank (48) through the connecting shaft (6).