Transmission function device for alternately pressing inner and outer presser feet of sewing machine head

Abstract

The utility model provides a transmission function device for alternately pressing an inner presser foot and an outer presser foot of a sewing machine head, and belongs to the technical field of sewing machines. The problem that an existing inner presser foot and an existing outer presser foot are large in impact force in the sewing process is solved. According to the transmission function device for alternate downward pressing of the inner and outer presser feet of the sewing machine head, a sewing machine comprises the machine head and a main shaft rotationally connected into the machine head, a transmission assembly is connected to the main shaft, an adjusting shaft is rotationally connected to the machine head, the transmission assembly is connected with the adjusting shaft and drives the adjusting shaft to rotate, and a connecting rod arranged in the vertical direction is connected to the adjusting shaft. The transmission function device comprises a triangular hinge block, one end of the swing rod is hinged to the upper end of the hinge block, and an outer presser foot rod and an inner presser foot rod are hinged to the front side and the rear side of the lower end of the hinge block respectively. The transmission function device for alternately pressing the inner presser foot and the outer presser foot of the sewing machine head adopts a lightweight design, so that the stability of the transmission function device is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewing machines and relates to a transmission function device for alternately pressing down inner and outer presser feet of a sewing machine head. Background Art

[0002] When the sewing machine is sewing fabric, the fabric is pressed against the feed dogs, and the friction between the feed dogs and the fabric is used to transport the fabric to ensure normal sewing. When sewing thicker fabrics, the large presser foot and the small presser foot need to be moved alternately and the needle plate and feed dogs need to be coordinated to achieve feeding.

[0003] For example, Chinese patent application [application publication number: CN114775175A] discloses a presser foot interaction amount adjustment and presser foot lifting mechanism, including a driving motor, a driving cam, a presser foot lifting assembly, a presser foot interaction amount adjustment assembly and a presser foot assembly, the presser foot lifting assembly includes a presser foot pressing plate, one end of the presser foot pressing plate is fixedly connected to the presser foot lifting shaft, the other end is provided with a first pin shaft, the outer presser foot component and the first connecting end of the triangular plate are hinged with the first pin shaft, the other end of the presser foot pressing plate is provided with a pressing plate part, and a reset rod is provided above the pressing plate part. A reset spring is mounted on the positioning rod, the lower end of the reset rod passes through the lower spring baffle and is limited below the lower spring baffle, and an upper spring baffle is arranged on the upper end, the two ends of the reset spring are respectively pressed against the upper spring baffle and the lower spring baffle, and the lower spring baffle abuts against the pressure plate part under the action of the reset spring, and a through hole is arranged on the pressure plate part for the lower end of the reset rod to pass through, the outer presser foot component is hinged to one end of the first hinge, the other end of the first hinge is hinged to the first pin shaft, and the second connecting end of the triangle plate is hinged to the inner presser foot component through the second hinge.

[0004] The above structure uses a triangle plate to adjust the interaction amount between the inner presser foot and the outer presser foot. However, when the sewing machine is sewing thicker fabrics, the inner presser foot rod and the outer presser foot rod need to be lifted a higher distance. As a result, when the inner presser foot rod and the outer presser foot rod are moved down, the impact force of the inner presser foot rod and the outer presser foot rod is relatively large, which will cause the fabric to be unable to pass smoothly, thereby generating friction and resistance. When the sewing needle penetrates the fabric, it is easy to encounter resistance, bend or break, and the phenomenon of skipped stitches is easy to occur, affecting the sewing quality. Utility Model Content

[0005] The purpose of the utility model is to solve the above-mentioned problems in the existing technology and to propose a transmission function device for alternately pressing down the inner and outer presser feet of a sewing machine head. The technical problem to be solved by the utility model is: how to solve the problem of large impact force of the existing inner and outer presser feet during sewing.

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

[0007] A transmission function device for alternately pressing the outer and inner presser feet of a sewing machine head. The sewing machine includes a head and a main shaft rotatably connected inside the head. A transmission assembly is connected to the main shaft. An adjusting shaft is rotatably connected to the head. It is characterized in that the transmission assembly is connected to the adjusting shaft and drives the adjusting shaft to rotate. A vertically arranged connecting rod is connected to the adjusting shaft. The lower end of the connecting rod is hinged to a swinging rod arranged in the front-back direction. This transmission function device includes a triangular hinge block. One end of the swinging rod is hinged to the upper end of the hinge block. The front and rear sides of the lower end of the hinge block are respectively hinged to an outer presser foot rod and an inner presser foot rod. The front and rear swinging of the hinge block drives the outer presser foot rod and the inner presser foot rod to move up and down alternately. The hinge blocks are all made of plastic materials. The outer presser foot rod and the inner presser foot rod are both hollow rods.

[0008] Working principle: The rotation of the main shaft drives the swinging of the transmission assembly. The transmission assembly is connected to the adjusting shaft, and the swinging of the transmission assembly drives the swinging of the adjusting shaft. The adjusting shaft is connected with a connecting rod, and the connecting rod swings along with the swinging of the adjusting shaft. The swinging rod is arranged in the front-back direction, so the lower end of the connecting rod pushes the swinging rod to move in the front-back direction. The movement of the swinging rod drives the upper end of the triangular hinge block to swing back and forth. The front and rear sides of the lower end of the hinge block are respectively hinged to an outer presser foot rod and an inner presser foot rod. When the swinging rod moves backward, it will push the inner presser foot rod downward and the outer presser foot rod upward. The inner presser foot connected below the inner presser foot rod presses the fabric tightly on the feed dog. When the swinging rod moves forward, it pushes the outer presser foot rod downward and the inner presser foot rod upward. The outer presser foot connected below the outer presser foot rod presses the fabric tightly on the needle plate, realizing the alternation of the outer presser foot rod and the inner presser foot rod. During the alternation operation, it can drive the fabric to move forward. One of the outer presser foot and the inner presser foot must press the fabric tightly on the needle plate and the feed dog before the other starts to move. Through the triangular hinge block, it is ensured that during the sewing process, the inner presser foot rod and the outer presser foot rod operate alternately. In order to reduce the downward impact force of the outer presser foot rod and the inner presser foot rod, by making the hinge block of plastic material and making the outer presser foot rod and the inner presser foot rod hollow rods, a lightweight design is adopted to reduce the inertia of the outer presser foot rod and the inner presser foot rod, as well as the inertia of the hinge block, so as to achieve the purpose of reducing the downward impact force of the outer presser foot rod and the inner presser foot rod and improving the stability of the transmission function device.

[0009] In the above-mentioned transmission function device for alternately pressing the outer and inner presser feet of the sewing machine head, a guide sleeve is sleeved on the outer presser foot rod. The guide sleeve is inserted into the head, and the upper end of the guide sleeve is close to the hinge block.

[0010] Since the outer presser foot rod is a hollow rod, the overall weight of the outer presser foot rod is relatively light. Through the setting of the guide sleeve, it is ensured that there is no radial displacement when the outer presser foot rod moves up and down, improving the stability of the transmission function device.

[0011] In the transmission function device for the alternating downward pressing of the inner and outer presser feet of the sewing machine head described above, a needle bar swing frame is sleeved on the inner presser foot bar. The upper end of the inner presser foot bar is hinged with a swing connecting rod. The upper end of the swing connecting rod is hinged with the lower end of a hinge block. The upper end of the inner presser foot bar and the swing connecting rod are hinged through a hinge shaft. One end of the hinge shaft is sleeved with a slider. The needle bar swing frame is provided with a chute along the vertical direction, and the slider can slide vertically in the chute.

[0012] When the inner presser foot bar moves up and down, the slider will slide vertically along the chute on the needle bar swing frame, improving the stability of the vertical movement of the inner presser foot bar. Moreover, by utilizing the existing structure of the needle bar swing frame without adding additional guiding parts, the integration degree of the sewing machine is improved.

[0013] In the transmission function device for the alternating downward pressing of the inner and outer presser feet of the sewing machine head described above, the front and rear side walls of the slider are provided with sliding planes arranged vertically, and the sliding planes are in contact with the groove walls of the chute.

[0014] Through the arrangement of the planes, the mating surface between the slider and the chute is increased, making the sliding of the slider along the chute more stable.

[0015] In the transmission function device for the alternating downward pressing of the inner and outer presser feet of the sewing machine head described above, both the swing connecting rod and the slider are made of plastic.

[0016] This structure makes the swing connecting rod and the slider lighter in weight, more in line with the lightweight design, reducing the inertia of swinging and improving the stability of the transmission function device.

[0017] In the transmission function device for the alternating downward pressing of the inner and outer presser feet of the sewing machine head described above, both the connecting rod and the swing rod are made of aluminum alloy.

[0018] By making the connecting rod and the swing rod of a metal with a lighter weight, the inertia of swinging can be reduced, the impact force on the outer presser foot bar and the inner presser foot bar can be reduced, and the stability of the transmission function device is improved.

[0019] In the transmission function device for the alternating downward pressing of the inner and outer presser feet of the sewing machine head described above, a limit sleeve is also hinged to the upper end of the outer presser foot bar. The hinge block is arranged inside the limit sleeve, and the left and right side walls of the hinge block are in contact with the inner wall of the limit sleeve.

[0020] Through the arrangement of the limit sleeve, the stability of the front and rear swinging of the hinge block is improved, preventing lateral movement and further improving the stability of the transmission function device.

[0021] In the transmission function device for the alternating downward pressing of the inner and outer presser feet of the sewing machine head described above, the limiting sleeve protrudes upward to form a reset rod arranged vertically. A reset spring is sleeved on the reset rod, and an adjusting knob partially located outside the machine head is sleeved on the reset rod. A limiting ring is formed by a protrusion on the inner wall of the adjusting knob. The upper end of the reset spring abuts against the limiting ring, and the lower end abuts against the upper end of the limiting sleeve.

[0022] Through the arrangement of the reset rod and the reset spring, the reset effect of the outer presser foot rod is improved, and the outer presser foot rod can quickly press the fabric against the needle plate.

[0023] In the transmission function device for the alternating downward pressing of the inner and outer presser feet of the sewing machine head described above, the transmission assembly includes an eccentric wheel connected to the main shaft and a swing frame. The eccentric wheel is connected to the swing frame, and the swing frame swings with the adjusting shaft. The rotation of the eccentric wheel can drive the adjusting shaft to swing through the swing frame.

[0024] Through the rotation of the main shaft, the eccentric wheel moves towards or away from the swing frame, thereby realizing the movement of multiple swing rods in the swing frame. The movement of the swing rods drives the adjusting shaft to swing, thereby realizing the alternating movement of the outer presser foot rod and the inner presser foot rod.

[0025] In the transmission function device for the alternating downward pressing of the inner and outer presser feet of the sewing machine head described above, the hinge pins of the connecting rod and the swing rod, the hinge pins of the swing rod and the hinge block, the hinge pins of the hinge block and the outer presser foot rod, the hinge pins of the hinge block and the inner presser foot rod, and the hinge shaft are all hollow rods.

[0026] The setting of this structure makes the mass at the hinge joint relatively light, facilitating swinging, reducing the weight of the transmission function device, further enhancing the lightweight design, and improving the stability in use.

[0027] Compared with the prior art, the present utility model has the following advantages: Through the triangular hinge block, it is ensured that during the sewing process, the inner presser foot rod and the outer presser foot rod operate alternately. In order to reduce the downward impact force of the outer presser foot rod and the inner presser foot rod, the hinge block is made of plastic material, and the outer presser foot rod and the inner presser foot rod are made of hollow rods, adopting a lightweight design to reduce the inertia of the outer presser foot rod and the inner presser foot rod, as well as the inertia of the hinge block, so as to achieve the purpose of reducing the downward impact force of the outer presser foot rod and the inner presser foot rod and improving the stability of the transmission function device. Description of the Drawings

[0028] Figure 1 It is a schematic structural diagram of the present utility model.

[0029] Figure 2 It is a schematic structural diagram of the present utility model without the installation of the machine head.

[0030] Figure 3It is a top view of the present utility model without the installation of the machine head.

[0031] Figure 4 It is Figure 3 the sectional view taken along A-A in

[0032] Figure 5 a partial structural schematic diagram of the present utility model.

[0033] In the figure, 1 is the machine head; 2 is the main shaft; 3 is the transmission assembly; 31 is the eccentric wheel; 32 is the swing frame; 4 is the adjusting shaft; 41 is the connecting rod; 5 is the swing rod; 6 is the hinge block; 7 is the outer presser foot rod; 71 is the guide sleeve; 72 is the limit sleeve; 73 is the reset rod; 74 is the reset spring; 75 is the adjusting knob; 75a is the limit ring; 8 is the inner presser foot rod; 81 is the swing connecting rod; 82 is the hinge shaft; 83 is the slider; 83a is the sliding plane; 9 is the needle bar swing frame; 91 is the chute. Specific embodiments

[0034] The following are specific embodiments of the present utility model and in combination with the attached drawings, the technical solutions of the present utility model are further described, but the present utility model is not limited to these embodiments.

[0035] As Figure 1 shown, for the transmission function device of the present sewing machine head with the outer and inner presser feet pressing down alternately, the sewing machine includes the machine head 1 and the main shaft 2 rotatably connected inside the machine head 1. A transmission assembly 3 is connected to the main shaft 2. The transmission assembly 3 includes an eccentric wheel 31 connected to the main shaft 2 and a swing frame 32. The eccentric wheel 31 is connected to the swing frame 32, and the swing frame 32 swings with the adjusting shaft 4. The rotation of the eccentric wheel 31 can drive the adjusting shaft 4 to swing through the swing frame 32.

[0036] Specifically, as Figures 1-5 shown, an adjusting shaft 4 is rotatably connected to the machine head 1. The transmission assembly 3 is connected to the adjusting shaft 4 and drives the adjusting shaft 4 to rotate. A connecting rod 41 arranged vertically is connected to the adjusting shaft 4. The lower end of the connecting rod 41 is hinged to a swing rod 5 arranged in the front-rear direction. The present transmission function device includes a hinge block 6 in the shape of a triangle. One end of the swing rod 5 is hinged to the upper end of the hinge block 6. The front and rear sides of the lower end of the hinge block 6 are respectively hinged to an outer presser foot rod 7 and an inner presser foot rod 8. The front and rear swing of the hinge block 6 drives the outer presser foot rod 7 and the inner presser foot rod 8 to move up and down alternately. The hinge block 6 is made of plastic material. The outer presser foot rod 7 and the inner presser foot rod 8 are both hollow rods. The connecting rod 41 and the swing rod 5 are both made of aluminum alloy.

[0037] Working principle: The rotation of the main shaft 2 drives the swing of the transmission component 3. The transmission component 3 is connected to the adjusting shaft 4. The swing of the transmission component 3 drives the swing of the adjusting shaft 4. The adjusting shaft 4 is connected with a connecting rod 41. The connecting rod 41 swings along with the swing of the adjusting shaft 4. The lower end of the connecting rod 41 pushes the swing rod 5 to move. The swing rod 5 moves in the front-rear direction, pushing the upper end of the triangular hinge block 6 to swing back and forth. The front and rear sides of the lower end of the hinge block 6 are respectively hinged with an outer presser foot rod 7 and an inner presser foot rod 8. When the swing rod 5 moves backward, it will push the inner presser foot rod 8 to move downward and the outer presser foot rod 7 to move upward. The inner presser foot connected to the lower part of the inner presser foot rod 8 presses the fabric tightly on the feed dog. When the swing rod 5 moves forward, it pushes the outer presser foot rod 7 to move downward and the inner presser foot rod 8 to move upward. The outer presser foot connected to the lower part of the outer presser foot rod 7 presses the fabric tightly on the needle plate, realizing the alternation of the outer presser foot rod 7 and the inner presser foot rod 8. Through the triangular hinge block 6, it is ensured that during the sewing process, the inner presser foot rod 8 and the outer presser foot rod 7 operate alternately. When operating alternately, they can drive the fabric to move forward. One of the outer presser foot and the inner presser foot must press the fabric tightly on the needle plate and the feed dog before the other starts to move. In order to reduce the downward impact force of the outer presser foot rod 7 and the inner presser foot rod 8, the hinge block 6 is made of plastic material, and the outer presser foot rod 7 and the inner presser foot rod 8 are made of hollow rods, adopting a lightweight design to reduce the inertia of the outer presser foot rod 7 and the inner presser foot rod 8, as well as the inertia of the hinge block 6, so as to achieve the purpose of reducing the downward impact force of the outer presser foot rod 7 and the inner presser foot rod 8 and improving the stability of the transmission function device.

[0038] As Figures 2-5 shown, a guide sleeve 71 is sleeved on the outer presser foot rod 7. The guide sleeve 71 is inserted into the machine head 1, and the upper end of the guide sleeve 71 is close to the hinge block 6. A needle bar swing frame 9 is sleeved on the inner presser foot rod 8. The upper end of the inner presser foot rod 8 is hinged with a swing link 81. The upper end of the swing link 81 is hinged with the lower end of the hinge block 6. The upper end of the inner presser foot rod 8 and the swing link 81 are hinged through a hinge shaft 82. One end of the hinge shaft 82 is sleeved with a slider 83. The needle bar swing frame 9 is provided with a chute 91 in the vertical direction. The slider 83 can slide vertically in the chute 91. It is characterized in that the front and rear side walls of the slider 83 have sliding planes 83a arranged vertically. The sliding planes 83a are attached to the groove walls of the chute 91. Both the swing link 81 and the slider 83 are made of plastic.

[0039] As Figures 2-4As shown, a limit sleeve 72 is also hinged to the upper end of the external presser foot rod 7. The hinge block 6 is arranged inside the limit sleeve 72, and the left and right side walls of the hinge block 6 are in contact with the inner wall of the limit sleeve 72. The limit sleeve 72 protrudes upward to form a reset rod 73 arranged vertically. A reset spring 74 is sleeved on the reset rod 73. An adjustment knob 75 partially located outside the machine head 1 is sleeved on the reset rod 73. A limit ring 75a is formed by protrusion on the inner wall of the adjustment knob 75. The upper end of the reset spring 74 abuts against the limit ring 75a, and the lower end abuts against the upper end of the limit sleeve 72. The hinge pins of the connecting rod 41 and the swing rod 5, the hinge pin of the swing rod 5 and the hinge block 6, the hinge pin of the hinge block 6 and the external presser foot rod 7, the hinge pin of the hinge block 6 and the internal presser foot rod 8, and the hinge shaft 82 are all hollow rods.

[0040] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A transmission function device for alternately pressing down the inner and outer presser feet of a sewing machine head, the sewing machine comprising a head (1) and a main shaft (2) rotatably connected to the head (1), a transmission assembly (3) being connected to the main shaft (2), and an adjustment shaft (4) being rotatably connected to the head (1), characterized in that: The transmission assembly (3) is connected to the adjustment shaft (4) and drives the adjustment shaft (4) to rotate. The adjustment shaft (4) is connected to a connecting rod (41) arranged vertically. The lower end of the connecting rod (41) is hinged with a swing rod (5) arranged in the front-back direction. The transmission function device comprises a triangular hinge block (6). One end of the swing rod (5) is hinged with the upper end of the hinge block (6). The front and rear sides of the lower end of the hinge block (6) are respectively hinged with an outer presser foot rod (7) and an inner presser foot rod (8). The front and rear swinging of the hinge block (6) drives the outer presser foot rod (7) and the inner presser foot rod (8) to move up and down alternately. The hinge block (6) is made of plastic material. The outer presser foot rod (7) and the inner presser foot rod (8) are both hollow rods.

2. The transmission function device for alternately pressing down the inner and outer presser feet of a sewing machine head according to claim 1, characterized in that: The outer presser foot rod (7) is sleeved with a guide sleeve (71), the guide sleeve (71) is plugged into the machine head (1), and the upper end of the guide sleeve (71) is close to the hinge block (6).

3. The transmission function device for alternately pressing down the inner and outer presser feet of a sewing machine head according to claim 1 or 2, characterized in that: The inner presser foot rod (8) is sleeved with a needle bar swing frame (9), the upper end of the inner presser foot rod (8) is hinged with a swing connecting rod (81), the upper end of the swing connecting rod (81) is hinged with the lower end of the hinge block (6), the upper end of the inner presser foot rod (8) and the swing connecting rod (81) are hinged through a hinge shaft (82), one end of the hinge shaft (82) is sleeved with a slide block (83), the needle bar swing frame (9) is vertically provided with a slide groove (91), and the slide block (83) can slide vertically in the slide groove (91).

4. The transmission function device for alternately pressing down the inner and outer presser feet of a sewing machine head according to claim 3, characterized in that: The front and rear side walls of the sliding block (83) have sliding planes (83a) arranged vertically, and the sliding planes (83a) are in contact with the groove walls of the sliding groove (91).

5. The transmission function device for alternately pressing down the inner and outer presser feet of a sewing machine head according to claim 3, characterized in that: The swing connecting rod (81) and the sliding block (83) are both made of plastic.

6. The transmission function device for alternately pressing down the inner and outer presser feet of a sewing machine head according to claim 1 or 2, characterized in that: The connecting rod (41) and the swing rod (5) are both made of aluminum alloy.

7. The transmission function device for alternately pressing down the inner and outer presser feet of a sewing machine head according to claim 1 or 2, characterized in that: The upper end of the outer presser foot rod (7) is also hinged to a limiting sleeve (72), the hinge block (6) is arranged in the limiting sleeve (72), and the left and right side walls of the hinge block (6) are in contact with the inner wall of the limiting sleeve (72).

8. The transmission function device for alternately pressing down the inner and outer presser feet of a sewing machine head according to claim 7, characterized in that: The limiting sleeve (72) protrudes upward to form a reset rod (73) arranged in a vertical direction, a reset spring (74) is sleeved on the reset rod (73), an adjustment knob (75) partially located outside the machine head (1) is sleeved on the reset rod (73), a limiting ring (75a) is protruded on the inner wall of the adjustment knob (75), the upper end of the reset spring (74) abuts against the limiting ring (75a), and the lower end abuts against the upper end of the limiting sleeve (72).

9. The transmission function device for alternately pressing down the inner and outer presser feet of a sewing machine head according to claim 1 or 2, characterized in that: The transmission assembly (3) comprises an eccentric wheel (31) and a swing frame (32) connected to the main shaft (2); the eccentric wheel (31) is connected to the swing frame (32); the swing frame (32) swings with the adjustment shaft (4); the rotation of the eccentric wheel (31) can drive the adjustment shaft (4) to swing via the swing frame (32).

10. The transmission function device for alternately pressing down the inner and outer presser feet of a sewing machine head according to claim 3, characterized in that: The hinge pins between the connecting rod (41) and the swing rod (5), the hinge pins between the swing rod (5) and the hinge block (6), the hinge pins between the hinge block (6) and the outer presser foot rod (7), the hinge pins between the hinge block (6) and the inner presser foot rod (8), and the hinge shaft (82) are all hollow rods.

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