Thread trapper device and sewing machine
The thread clamp device with double elastic locking design enables fine adjustment and stability of sewing machine thread tension, solving the problems of unstable thread tension and wobbling in existing technology, and improving sewing quality and stability under low thread tension.
Patent Information
- Application Number
- CN202511917503.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-18
- Publication Date
- 2026-02-10
AI Technical Summary
Existing sewing machine thread tensioners are difficult to finely adjust within a low thread tension range, resulting in unstable thread tension, affecting sewing quality, and are prone to shaking and abnormal noise, failing to meet the sewing requirements of ultra-thin materials.
It adopts a dual elastic locking design, with the inner and outer elastic elements acting in opposite directions on the front and rear sides of the rear clamping reel. The pressure of the outer elastic element is adjusted by the nut, while the inner elastic element provides a balancing force, enabling fine adjustment of the line tension and maintaining the stability of the clamping reel at low line tension, avoiding shaking and abnormal noise.
It achieves continuous and stable adjustment from low to high thread tension, improves sewing quality, avoids thread tangling, ensures stability and noise-free operation at low thread tension, and meets the sewing requirements of ultra-thin materials.
Smart Images
Figure CN121496672A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of sewing machines, in particular to a thread clamp device and a sewing machine comprising the same. BACKGROUND
[0002] The thread clamp of a sewing machine is a key component for controlling the tension of sewing thread. The conventional thread clamp adopts a single spring design, including a stud, two thread clamps, a spring and an adjusting nut. The stud is sequentially threaded through the two thread clamps and the single spring, and then threadedly connected with the adjusting nut. The two thread clamps are pressed tightly by the pressure of the spring, and the sewing thread is clamped between the two thread clamps. The pressure of the spring is adjusted by the adjusting nut to control the clamping force between the two thread clamps, thereby adjusting the thread tension. This design has several problems. First, the single spring cannot achieve fine thread tension adjustment, especially in the low thread tension range. The spring pressure changes nonlinearly, resulting in unstable thread tension and affecting the sewing quality. Second, when the thread tension is low, the pressure between the thread clamps decreases, which easily causes the thread clamps to shake and collide, resulting in abnormal noise. Third, the stud does not fix the thread clamps, which also exacerbates the shaking problem. Therefore, the existing thread clamp device cannot be adjusted to a stable low thread tension, and cannot meet the sewing requirements of ultra-thin materials such as netting, chiffon and silk, which require extremely low thread tension. SUMMARY
[0003] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present application is to provide a thread clamp device capable of achieving stable low thread tension.
[0004] In order to solve the above technical problems, the present application adopts the following technical solutions:
[0005] The present application provides a thread clamp device, comprising a stud and a front thread clamp, a middle thread clamp, an inner elastic member, a rear thread clamp, an outer elastic member and a nut which are sequentially sleeved on the stud in the axial direction from front to rear. The front thread clamp and the middle thread clamp form a thread clamping position therebetween. The middle thread clamp is movably sleeved on the stud in the axial direction. The rear thread clamp has a pressing portion which is in abutment with the middle thread clamp and a cap portion which is recessed to the rear side relative to the pressing portion. The pressing portion is connected to the front end outer periphery of the cap portion. The cap portion is movably sleeved on the stud in the axial direction and forms an accommodating cavity with the stud. The inner elastic member is located in the accommodating cavity and elastically presses between the middle thread clamp and the rear thread clamp. The outer elastic member elastically presses between the rear thread clamp and the nut. The nut is threadedly connected with the rear end portion of the stud.
[0006] Preferably, a fixing boss is provided on the stud, and the fixing boss is located at the rear side of the front thread clamp. The front thread clamp is in abutment with the front end face of the fixing boss to be fixed.
[0007] Preferably, the rear end of the fixing boss extends to the rear of the accommodating cavity, and the middle thread clamp is movably sleeved on the fixing boss in the axial direction.
[0008] Preferably, the front clamping disc is fixedly connected to the stud.
[0009] Preferably, the rear end of the stud has a slot that runs radially through the outer circumferential surface of the stud, and the front end of the slot is located on the rear side of the center clamping coil.
[0010] Preferably, the inner elastic element and / or the outer elastic element are tower-shaped springs with diameters gradually decreasing from front to back.
[0011] Preferably, the outer elastic element is fitted over the cap portion, and the front end of the outer elastic element presses against the pressing portion.
[0012] Preferably, the position where the pressing part fits against the middle clamping coil corresponds to the clamping position.
[0013] The present invention also provides a sewing machine including the thread clamp device as described above.
[0014] Compared with the prior art, the present invention has significant progress:
[0015] The thread clamping device of the present invention designs the rear thread clamping reel as a cap shape and sets an inner elastic element inside the cap. The inner and outer elastic elements act in opposite directions on the front and rear sides of the rear thread clamping reel, forming a double elastic element locking design. The outer elastic element provides the sewing thread tension, and the inner elastic element provides the balancing force. The inner and outer elastic elements work together through force locking to achieve fine adjustment of thread tension. When the nut is loosened, the elastic force of the outer elastic element decreases and the elastic force of the inner elastic element becomes dominant, which reduces the clamping force between the rear and front thread clamping reels to a minimum, thereby reducing the clamping force between the middle and front thread clamping reels to a minimum, and obtaining low thread tension. Therefore, the thread clamping device of the present invention can achieve continuous and stable fine adjustment from low thread tension to high thread tension, effectively improving sewing quality. Furthermore, at low thread tension, the rear thread clamping reel can remain stable under the support of the inner elastic element, thus avoiding abnormal noise and achieving a stable low thread tension state. Furthermore, the thread clamping device of the present invention also provides a middle thread clamping plate between the front thread clamping plate and the rear thread clamping plate, forming a thread clamping position between the front thread clamping plate and the middle thread clamping plate. The middle thread clamping plate separates the thread clamping position from the inner elastic element provided in the cap of the rear thread clamping plate, which can prevent the sewing thread from getting wrapped around the area where the inner elastic element is located and causing thread wrapping failure. Attached Figure Description
[0016] Figure 1 This is a front view schematic diagram of one embodiment of the wire clamp device of the present invention.
[0017] Figure 2 yes Figure 1 A schematic cross-sectional view of the wire clamp device is shown.
[0018] Figure 3 yesFigure 1 A schematic diagram of the split components of the wire clamp device is shown.
[0019] Figure 4 This is a cross-sectional schematic diagram of another embodiment of the wire clamp device of the present invention.
[0020] The reference numerals in the attached figures are explained as follows:
[0021] 1. Stud; 11. Fixing boss; 12. Slot; 2. Front clamping reel; 3. Inner elastic element; 4. Rear clamping reel; 41. Pressing part; 42. Cap part; 43. Receiving cavity; 5. Outer elastic element; 6. Nut; 7. Middle clamping reel. Detailed Implementation
[0022] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.
[0023] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0025] Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0026] like Figures 1 to 4The image shows an embodiment of the wire clamp device provided by the present invention. This embodiment of the wire clamp device includes a stud 1 and, along the axial direction of the stud 1, a front wire clamping disc 2, a middle wire clamping disc 7, an inner elastic element 3, a rear wire clamping disc 4, an outer elastic element 5, and a nut 6, which are sequentially fitted onto the stud 1 from front to back. In the description of the present invention, for ease of description, the two ends of the axial direction of the stud 1 are defined as the "front" side and the "rear" side, respectively, and the front-back direction is the axial direction of the stud 1. Specifically, it is defined as... Figure 1 and Figure 2 The left side of the paper is the "front" side. Figure 1 and Figure 2 The right side of the paper is the "back" side.
[0027] In this design, the nut 6 and the rear end of the stud 1 are connected by a threaded engagement. The outer elastic element 5 elastically presses against the rear clamping reel 4 and the nut 6. The nut 6 presses against the rear end of the outer elastic element 5, causing the front end of the outer elastic element 5 to press the rear clamping reel 4 against the middle clamping reel 7, and causing the middle clamping reel 7 to press against the front clamping reel 2. By tightening the nut 6, the relative position of the nut 6 and the stud 1 can be changed, thereby changing the compression amount of the outer elastic element 5 and adjusting the pressure exerted by the outer elastic element 5 on the rear clamping reel 4, that is, adjusting the pressure of the rear clamping reel 4 against the middle clamping reel 7, thereby adjusting the clamping force between the front clamping reel 2 and the middle clamping reel 7.
[0028] The front thread clamping reel 2 is disc-shaped, and the middle thread clamping reel 7 is also disc-shaped. A thread clamping position is formed between the front thread clamping reel 2 and the middle thread clamping reel 7, which fit together at the thread clamping position to hold the sewing thread. The middle thread clamping reel 7 can be axially moved and fitted onto the stud 1.
[0029] The rear clamping reel 4 is cap-shaped. The rear clamping reel 4 has a pressing portion 41 and a cap portion 42. The pressing portion 41 fits against the middle clamping reel 7. Preferably, the position where the pressing portion 41 fits against the middle clamping reel 7 corresponds to the clamping position between the front clamping reel 2 and the middle clamping reel 7. The cap portion 42 is recessed rearward relative to the pressing portion 41, forming a receiving space. The pressing portion 41 is connected to the outer periphery of the front end of the cap portion 42, making the rear clamping reel 4 overall cap-shaped. The cap portion 42 is axially movable and fitted onto the stud 1, and a receiving cavity 43 is formed between the cap portion 42 and the stud 1. Preferably, an outer elastic member 5 is fitted onto the cap portion 42, and the front end of the outer elastic member 5 presses against the pressing portion 41. By turning the nut 6 to adjust the pressure of the outer elastic element 5 acting on the rear clamping plate 4, the clamping force between the pressing part 41 and the middle clamping plate 7 can be changed, thereby adjusting the clamping force between the middle clamping plate 7 and the front clamping plate 2, that is, adjusting the thread tension of the sewing thread clamped between the two.
[0030] The inner elastic element 3 is located within the receiving cavity 43, and the inner elastic element 3 elastically presses against the middle clamping reel 7 and the rear clamping reel 4. Preferably, the front end of the inner elastic element 3 presses against the middle clamping reel 7, and the rear end of the inner elastic element 3 presses against the rear side wall of the cap 42 of the rear clamping reel 4.
[0031] Therefore, in this embodiment, the thread clamping device consists of an inner elastic element 3 and an outer elastic element 5 acting in opposite directions on the front and rear sides of the rear thread clamping disc 4, forming a double elastic element locking design. The outer elastic element 5 provides the sewing thread tension, while the inner elastic element 3 provides the balancing force. The inner elastic element 3 and the outer elastic element 5 work together through force locking to achieve fine adjustment of thread tension. When the nut 6 is loosened, the elastic force of the outer elastic element 5 decreases, and the elastic force of the inner elastic element 3 becomes dominant. This reduces the clamping force between the rear thread clamping disc 4 and the middle thread clamping disc 7 to a minimum, thereby reducing the clamping force between the middle thread clamping disc 7 and the front thread clamping disc 2 to a minimum, resulting in low thread tension. Therefore, the thread clamping device in this embodiment can achieve continuous and stable fine adjustment from low thread tension to high thread tension, effectively improving sewing quality. Furthermore, at low thread tension, the rear thread clamping disc 4 can remain stable under the support of the inner elastic element 3, thus avoiding abnormal noise and achieving a stable low thread tension state.
[0032] The thread clamping device in this embodiment also provides a middle thread clamping plate 7 between the front thread clamping plate 2 and the rear thread clamping plate 4, forming a thread clamping position between the front thread clamping plate 2 and the middle thread clamping plate 7. The middle thread clamping plate 7 separates the thread clamping position from the inner elastic element 3 located in the cap 42 of the rear thread clamping plate 4, which can prevent the sewing thread from getting wrapped around the area where the inner elastic element 3 is located and causing thread wrapping failure.
[0033] like Figure 1 , Figure 2 and Figure 3 As shown, in one embodiment, a fixing boss 11 is provided on the outer peripheral surface of the stud 1, and the fixing boss 11 is located behind the front clamping plate 2. The front clamping plate 2 is fixed by abutting against the front end face of the fixing boss 11. The front clamping plate 2 can be pressed and fixed to the front end face of the fixing boss 11 by other components provided on the outer peripheral surface of the front end of the stud 1. The front clamping plate 2 is fixed by abutting against the front end face of the fixing boss 11, so that the front clamping plate 2 and the stud 1 are fixed to each other, thereby eliminating the shaking of the front clamping plate 2 and further ensuring the stability of the line tension at low line tension. Preferably, the rear end of the fixing boss 11 extends rearward to the receiving cavity 43, and the middle clamping plate 7 is axially movable and sleeved on the fixing boss 11.
[0034] like Figure 4As shown, in another embodiment, the front clamping disc 2 and the stud 1 can also be fixedly connected to eliminate the wobbling of the front clamping disc 2 and further ensure the stability of the wire tension at low wire tension. Therefore, the fixing boss 11 does not need to be provided on the outer circumferential surface of the stud 1. The fixed connection between the front clamping disc 2 and the stud 1 can be achieved through methods including but not limited to threaded connection, welding, riveting, and crimping.
[0035] like Figure 2 and Figure 4 As shown, in this embodiment, preferably, the rear end of the stud 1 has a slot 12 that radially penetrates the outer circumference of the stud 1. The slot 12 divides the rear end of the stud 1 into two parts and spreads them at a certain angle, which makes the connection between the rear end of the stud 1 and the nut 6 tighter and prevents the nut 6 from shaking. The front end of the slot 12 is located on the rear side of the middle clamping reel 7, so that the slot 12 avoids the wire passage point of the stud 1 between the front clamping reel 2 and the middle clamping reel 7. That is, the wire passage point of the stud 1 is not slotted, which can avoid the wire hanging at the slot 12 and cause unstable wire tension.
[0036] like Figure 2 and Figure 4 As shown, in this embodiment, both the inner elastic element 3 and the outer elastic element 5 are springs. Preferably, the inner elastic element 3 is a tower-shaped spring with a diameter that gradually decreases from front to back, and the outer elastic element 5 is a tower-shaped spring with a diameter that gradually decreases from front to back. Using tower-shaped springs for both the inner elastic element 3 and the outer elastic element 5 can provide stable linear elastic force and improve adjustment accuracy.
[0037] Based on the thread clamp device of the present invention, this embodiment also provides an embodiment of the sewing machine of the present invention, the sewing machine of this embodiment including any of the thread clamp devices described above in this embodiment.
[0038] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.
Claims
1. A wire clamping device, characterized in that, The device includes a stud (1) and a front wire clamping disc (2), a middle wire clamping disc (7), an inner elastic element (3), a rear wire clamping disc (4), an outer elastic element (5), and a nut (6) sequentially fitted onto the stud (1) from front to back along the axial direction of the stud (1). The front wire clamping disc (2) and the middle wire clamping disc (7) form a wire clamping position. The middle wire clamping disc (7) is axially movable and fitted onto the stud (1). The rear wire clamping disc (4) has a pressing part (41) that fits against the middle wire clamping disc (7) and a cap that is recessed rearward relative to the pressing part (41). (42) The pressing part (41) is connected to the outer periphery of the front end of the cap (42). The cap (42) is axially movable and is sleeved on the stud (1) to form a receiving cavity (43) with the stud (1). The inner elastic member (3) is located in the receiving cavity (43) and elastically presses against the middle clamping plate (7) and the rear clamping plate (4). The outer elastic member (5) elastically presses against the rear clamping plate (4) and the nut (6). The nut (6) is connected to the rear end of the stud (1) by a threaded connection.
2. The wire clamp device according to claim 1, characterized in that, The stud (1) is provided with a fixing boss (11), which is located on the rear side of the front clamping plate (2). The front clamping plate (2) is fixed to the front end face of the fixing boss (11).
3. The wire clamp device according to claim 2, characterized in that, The rear end of the fixed boss (11) extends rearward to the receiving cavity (43), and the middle clamping plate (7) is axially movable and fitted onto the fixed boss (11).
4. The wire clamp device according to claim 1, characterized in that, The front clamping disc (2) is fixedly connected to the stud (1).
5. The wire clamp device according to claim 1, characterized in that, The rear end of the stud (1) is provided with a slot (12) that runs radially through the outer circumference of the stud (1), and the front end of the slot (12) is located on the rear side of the middle clamping disc (7).
6. The wire clamp device according to claim 1, characterized in that, The inner elastic element (3) and / or the outer elastic element (5) are tower-shaped springs with diameters gradually decreasing from front to back.
7. The wire clamp device according to claim 1, characterized in that, The outer elastic member (5) is fitted over the cap (42), and the front end of the outer elastic member (5) presses against the pressing part (41).
8. The wire clamp device according to claim 1, characterized in that, The position where the pressing part (41) fits against the middle clamping coil (7) corresponds to the clamping position.
9. A sewing machine, characterized in that, Includes the wire clamp device as described in any one of claims 1 to 8.