Presser foot assembly

Abstract

The utility model provides a presser foot assembly, and belongs to the technical field of sewing machines. The presser foot solves the problem that when an existing presser foot is too hard, cloth is prone to being stuck. The presser foot assembly comprises a presser foot handle, a presser foot plate and an auxiliary plate, the presser foot plate is hinged to the bottom end of the presser foot handle, a rod-shaped fixing rod is fixedly connected to the position, behind the presser foot handle, of the upper surface of the presser foot plate, the fixing rod is sleeved with the auxiliary plate, the rear end of the auxiliary plate extends out of the presser foot plate, and the auxiliary plate can slide up and down along the fixing rod. A spring is connected between the upper surface of the auxiliary plate and the top end of the fixing rod. The presser foot assembly can avoid jamming when a hard stem is too hard, so that the sewing process is smoothly carried out.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewing machines and relates to a presser foot assembly. Background Art

[0002] A sewing machine is a machine that sews fabric together using thread. Overlock sewing involves the use of a needle and looper thread, either self-joined or interconnected, to hem or sew the fabric together. An overlock sewing machine is a common sewing machine that achieves overlock sewing. The machine's table is equipped with a presser foot and feed dogs, which work together to feed the fabric.

[0003] Chinese patent documents disclose a sewing machine and a sewing machine presser foot [Application Number: CN201920328721.3; Publication Number: CN209602763U]. The presser foot comprises a presser foot handle and a presser foot base rotatably connected to the bottom of the handle. The presser foot base comprises a base body and a presser foot guard. The presser foot guard is fixed to the base body via screws, with the rear side of the presser foot guard extending beyond the rear end of the base body. The presser foot guard is used to press thread braids.

[0004] At the seams or folds of the fabric, a hard stem of multiple layers of fabric will be formed. When the hard stem passes through the front end of the base plate body, the hard stem will lift the front end of the base plate body. Since the middle part of the base plate body is hinged to the bottom of the presser foot handle, the rear end of the base plate body rotates downward at this time, and the presser foot guard is completely fixed on the base plate body and the presser foot guard extends out of the rear end of the base plate body. If the hard stem is thick, it is easy to cause the rear end of the presser foot guard to press the fabric tightly against the table, causing the fabric to be stuck and the overlock sewing machine to be unable to feed the fabric normally. Utility Model Content

[0005] The purpose of the utility model is to solve the above problems existing in the prior art and propose a presser foot assembly to solve the technical problem that the existing presser foot is prone to getting stuck in the fabric when the fabric is too hard.

[0006] The purpose of this utility model can be achieved through the following technical solutions:

[0007] A presser foot assembly comprises a presser foot handle, a presser foot plate and an auxiliary plate, wherein the presser foot plate is hinged on the bottom end of the presser foot handle, and a rod-shaped fixing rod is fixedly connected to the upper surface of the presser foot plate and located behind the presser foot handle, and the auxiliary plate is sleeved on the fixing rod and the rear end of the auxiliary plate extends out of the presser foot. The auxiliary plate is characterized in that the auxiliary plate can slide up and down along the fixing rod, and a spring is connected between the upper surface of the auxiliary plate and the top end of the fixing rod.

[0008] When feeding fabric of normal thickness, the spring acts on the auxiliary plate to make the auxiliary plate rest against and be fixed on the upper surface of the presser foot, and the rear end of the auxiliary plate is used to block the thread braid. When a thicker hard stem passes the front end of the presser foot, the front end of the presser foot is lifted upward, and the rear end of the presser foot rotates downward. The rear end of the auxiliary plate presses the fabric against the table. At this time, the auxiliary plate is subjected to the reaction force of the table to push the spring away and slide upward along the fixed rod, avoiding crushing the fabric and allowing the fabric to be fed smoothly. In addition, when a thicker hard stem leaves the presser foot and reaches the auxiliary plate, the hard stem can also push the auxiliary plate to slide upward, avoiding jamming of the fabric when the hard stem passes through the auxiliary plate. When the hard stem has completely passed through the presser foot assembly, the spring generates a reset force on the auxiliary plate, causing the auxiliary plate to rest against the presser foot again. Therefore, this presser foot assembly can avoid jamming caused by overly hard stems, allowing the sewing process to proceed smoothly.

[0009] In the above-mentioned presser foot assembly, the fixing rod is an axial screw, the threaded section of the axial screw is threadedly connected to the presser foot plate, the auxiliary plate is sleeved on the axial section of the axial screw, and the top end of the spring rests on the head of the axial screw.

[0010] The threaded section of the axial screw is stably connected to the pressure foot plate, and the auxiliary plate is sleeved on the axial section of the axial screw to make the auxiliary plate slide up and down smoothly, thereby preventing the auxiliary plate from being. In addition, the axial screw is not only easy to install, but also a standard part that can be purchased directly at a low cost.

[0011] In the above-mentioned presser foot assembly, the spring is sleeved on the fixing rod. In this way, the fixing rod has a limiting effect on the spring, preventing the spring from radially expanding and affecting normal use.

[0012] In the aforementioned presser foot assembly, the presser foot plate has a vertically defined insertion hole, and the auxiliary plate has a pin protruding toward the presser foot plate. The pin is inserted into the insertion hole and can move up and down within the insertion hole. The combination of the insertion hole and the pin acts as a circumferential limiter for the auxiliary plate, preventing it from rotating about the fixed rod, thereby ensuring that the auxiliary plate blocks the wire braid.

[0013] In the aforementioned presser foot assembly, the auxiliary plate has a vertically extending insertion hole. The presser foot plate has a pin protruding toward the auxiliary plate. The pin is inserted into the insertion hole, allowing the auxiliary plate to move up and down along the pin. The combination of the insertion hole and the pin acts as a circumferential limiter for the auxiliary plate, preventing it from rotating around the fixed rod, thereby ensuring that the auxiliary plate blocks the wire braid.

[0014] In the aforementioned presser foot assembly, the insertion hole is cylindrical, and the cross-section of the insertion post is rectangular. This reduces the contact area between the outer side of the insertion post and the wall of the insertion hole, reducing sliding friction between the two. This allows the auxiliary plate to slide upward smoothly when the presser foot is too hard, preventing the fabric from getting stuck and ensuring smooth sewing.

[0015] In the above-mentioned presser foot assembly, one side of the auxiliary plate has a lower convex strip bent downward, the lower convex strip is located behind the presser foot plate, and the lower surface of the lower convex strip is higher than the lower surface of the presser foot plate.

[0016] When the thread braid extends from the rear of the presser foot, the lower ridge further blocks the braid, preventing it from moving out of the auxiliary plate. The lower surface of the lower ridge is higher than the lower surface of the presser foot, preventing it from contacting the fabric during normal sewing, thereby avoiding increased resistance during fabric feeding and ensuring smooth sewing.

[0017] In the aforementioned presser foot assembly, a gap is provided between the front end of the lower ridge and the rear end of the presser foot plate. This prevents the lower ridge and the presser foot plate from getting stuck when the auxiliary plate slides up and down, allowing the auxiliary plate to slide smoothly, thereby preventing the fabric from getting stuck when the material is too hard, and ensuring smooth sewing.

[0018] In the presser foot assembly, a chamfer is provided between the front end surface of the lower convex strip and the lower surface of the lower convex strip. The chamfer can prevent hard stems from getting stuck in the gap between the lower convex strip and the presser foot after passing through the presser foot, so that the sewing process can proceed smoothly.

[0019] Compared with the prior art, the utility model has the following advantages:

[0020] The auxiliary plate slides up and down along the fixed rod, and a spring is connected between the upper surface of the auxiliary plate and the top of the fixed rod. This allows the auxiliary plate to block thread strands during normal sewing, but also to adaptively slide upward when the material is too hard to prevent it from getting stuck. The arrangement of the socket and the pin prevents the auxiliary plate from rotating around the fixed rod, allowing the auxiliary plate to block thread strands during normal sewing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a three-dimensional diagram of the first embodiment of the presser foot assembly.

[0022] Figure 2 It is a three-dimensional diagram of the first embodiment of the presser foot assembly from another perspective.

[0023] Figure 3 This is a partial cross-sectional view of the auxiliary plate of the first embodiment of the presser foot assembly.

[0024] In the figure, 1, presser foot handle; 2, presser foot plate; 2a, socket; 3, auxiliary plate; 3a, lower convex strip; 3b, chamfer; 3c, plug post; 4, fixing rod; 4a, threaded section; 4b, axial section; 5, spring. DETAILED DESCRIPTION

[0025] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0026] Example 1

[0027] like Figure 1 As shown, a presser foot assembly includes a presser foot handle 1, a presser foot plate 2, and an auxiliary plate 3. The middle portion of the presser foot plate 2 is hinged to the bottom end of the presser foot handle 1. A rod-shaped fixing rod 4 is fixedly connected to the upper surface of the presser foot plate 2 and located behind the presser foot handle 1. The auxiliary plate 3 is mounted on the fixing rod 4 and can slide up and down along the fixing rod 4. The rear end of the auxiliary plate 3 extends out of the presser foot plate 2. That is, the fixing rod 4 passes through the auxiliary plate 3 and is fixedly connected to the presser foot plate 2. A spring 5 is connected between the upper surface of the auxiliary plate 3 and the top end of the fixing rod 4.

[0028] like Figure 2 and Figure 3 As shown, one side of the auxiliary plate 3 has a lower ridge 3a formed by bending downward. The lower ridge 3a is located behind the presser foot 2, and the lower surface of the lower ridge 3a is higher than the lower surface of the presser foot 2. There is a distance between the front end surface of the lower ridge 3a and the rear end surface of the presser foot 2. A chamfer 3b is provided between the front end surface of the lower ridge 3a and the lower surface of the lower ridge 3a. The rear end surface of the lower ridge 3a is an arc surface.

[0029] like Figure 1 and Figure 3 As shown, the presser foot plate 2 is provided with a socket 2a in the up-down direction, and the auxiliary plate 3 has a pin 3c protruding toward the presser foot plate 2. The pin 3c is inserted into the socket 2a and can move up and down. The socket 2a is a cylindrical hole, and the cross-section of the pin 3c is rectangular. The fixing rod 4 is an axial screw, and the threaded section 4a of the axial screw is threadedly connected to the presser foot plate 2. The auxiliary plate 3 is mounted on the axial section 4b of the axial screw. The spring 5 is mounted on the axial section 4b of the axial screw, and the top end of the spring 5 rests on the head of the axial screw. The spring 5 is a tower spring, which allows the auxiliary plate 3 to have more space to slide up and down.

[0030] When feeding fabric of normal thickness, spring 5 acts on auxiliary plate 3, forcing it to rest against and secure it to the upper surface of presser foot 2. The rear end of auxiliary plate 3 serves as a thread retaining device. When a thick, hard stem passes the front end of presser foot 2, the front end of presser foot 2 lifts upward, while the rear end of presser foot 2 rotates downward, pressing the fabric against the overlock machine's table. The reaction force of the table pushes spring 5 against auxiliary plate 3, causing it to slide upward along fixed rod 4, preventing the fabric from being crushed. Pin 3c then slides upward in socket 2a, allowing the fabric to be fed smoothly. Furthermore, when a thick, hard stem leaves presser foot 2 and reaches auxiliary plate 3, the stem pushes auxiliary plate 3 upward, preventing the fabric from becoming stuck when it passes the lower ridge 3a of auxiliary plate 3. Once the stem has completely passed through the presser foot assembly, spring 5 exerts a restoring force on auxiliary plate 3, resetting it to rest against presser foot 2. Therefore, this presser foot assembly prevents jamming caused by excessively hard stems, ensuring a smooth sewing process.

[0031] Example 2

[0032] The auxiliary plate 3 has an insertion hole 2a formed in the vertical direction, and the presser foot plate 2 has a pin 3c protruding toward the auxiliary plate 3. The pin 3c is inserted into the insertion hole 2a and the auxiliary plate 3 can move up and down along the pin 3c. Other structures are the same as those in the first embodiment.

[0033] Example 3

[0034] The fixing rod 4 is a pin, which is inserted and fixed tightly on the presser foot plate 2. Other structures are the same as those in the first embodiment.

[0035] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

Claims

1. A presser foot assembly, comprising a presser foot handle (1), a presser foot plate (2) and an auxiliary plate (3), wherein the presser foot plate (2) is hinged to the bottom end of the presser foot handle (1), a rod-shaped fixed rod (4) is fixedly connected to the upper surface of the presser foot plate (2) behind the presser foot handle (1), the auxiliary plate (3) is sleeved on the fixed rod (4) and the rear end of the auxiliary plate (3) extends out of the presser foot plate (2), characterized in that: The auxiliary plate (3) can slide up and down along the fixed rod (4), and a spring (5) is connected between the upper surface of the auxiliary plate (3) and the top end of the fixed rod (4).

2. The presser foot assembly according to claim 1, wherein: The fixing rod (4) is an axial screw, the threaded section (4a) of the axial screw is threadedly connected to the pressure foot plate (2), the auxiliary plate (3) is sleeved on the axial section (4b) of the axial screw, and the top end of the spring (5) abuts against the head of the axial screw.

3. The presser foot assembly according to claim 1, wherein: The spring (5) is sleeved on the fixing rod (4).

4. The presser foot assembly according to claim 1, wherein: The presser foot plate (2) is provided with an insertion hole (2a) in the up-down direction, and the auxiliary plate (3) is provided with an insertion column (3c) protruding toward the presser foot plate (2), and the insertion column (3c) is inserted into the insertion hole (2a) and can move up and down in the insertion hole (2a).

5. The presser foot assembly according to claim 1, wherein: The auxiliary plate (3) is provided with an insertion hole (2a) in the up-down direction, and the presser foot plate (2) is provided with an insertion column (3c) protruding toward the auxiliary plate (3). The insertion column (3c) is inserted into the insertion hole (2a) and the auxiliary plate (3) can move up and down along the insertion column (3c).

6. The presser foot assembly according to claim 4 or 5, characterized in that: The insertion hole (2a) is a cylindrical hole, and the cross section of the insertion column (3c) is rectangular.

7. The presser foot assembly according to any one of claims 1 to 5, characterized in that: One side of the auxiliary plate (3) has a lower convex strip (3a) formed by bending downwards. The lower convex strip (3a) is located behind the presser foot plate (2), and the lower surface of the lower convex strip (3a) is higher than the lower surface of the presser foot plate (2).

8. The presser foot assembly according to claim 7, wherein: There is a spacing distance between the front end surface of the lower convex strip (3a) and the rear end surface of the presser foot plate (2).

9. The presser foot assembly according to claim 7, wherein: A chamfer (3b) is provided between the front end surface of the lower convex strip (3a) and the lower surface of the lower convex strip (3a).

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