High-stability crank connecting rod mechanism for sewing machine

Abstract

The high-stability crank connecting rod mechanism for the sewing machine comprises a supporting rod, a sewing machine pedal is arranged on one side of the bottom of the supporting rod, a flywheel is arranged on the other side of the supporting rod, a transmission crank is installed on the top of the supporting rod through a bearing, a crank shaft is fixed to one end of the transmission crank, and the other end of the transmission crank is provided with a connecting rod. The crankshaft is sleeved with a transmission connecting rod, the portions, on the two sides of the transmission connecting rod, of the crankshaft are sleeved with a first positioning check ring and a second positioning check ring respectively, and a fastening crank is arranged on one side of the crankshaft. According to the utility model, the crank can be positioned, the gap between the crank and the connecting rod is reduced, the crank and the connecting rod are not easy to swing during transmission, the operation stability of the mechanism is improved, the abrasion condition is reduced, and the service life is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of sewing machine technology, specifically a highly stable crank-connecting rod mechanism for sewing machines. Background Technology

[0002] A sewing machine is a device used to sew together materials such as fabric and leather. It primarily uses one or more sewing threads to create one or more stitches on the fabric, interweaving or sewing together one or more layers of material. Sewing machines can sew fabrics such as cotton, linen, silk, wool, and synthetic fibers, as well as products made of leather, plastic, and paper. The stitches produced are neat, beautiful, flat, and strong. Sewing machines are fast and easy to use. The crank-connecting rod mechanism is a crucial drive mechanism in a sewing machine. Through this mechanism, the reciprocating linear motion of the operator's foot pedal is converted into the rotational motion of the flywheel or spindle. This conversion process enables the sewing machine to perform continuous sewing actions.

[0003] Chinese patent CN207958699U discloses a crank-connecting rod mechanism for a sewing machine, including a first connecting sleeve. A first connecting rod is welded to the right side of the first connecting sleeve. The right end of the first connecting rod is bonded to a grooved rod. The grooved rod is movably connected to an inner fixed rod via a screw. The end of the screw is threadedly engaged with the end of a hollow seat. The end of the grooved rod is machined with an internal threaded hole that engages with the screw thread. A second connecting rod is fixedly connected to the right end of the hollow seat. The second connecting rod is rotatably connected to two first connecting plates via a rotating shaft seat. A shock-absorbing spring is welded and installed in the groove of the first connecting plate. The lower end of the shock-absorbing spring is fixedly connected to a slider. A second connecting plate is bonded to the bottom of the slider.

[0004] The aforementioned crank-connecting rod mechanism, while allowing the distance between the first connecting sleeve and the pivot seat to be adjusted as needed, and the connection between the first connecting plate and the second connecting plate to be movable, enabling the sewing machine to operate more stably, has a gap between the crank and the connecting rod. Furthermore, prolonged friction at the connection point can easily cause wear, leading to loosening after extended operation. This can cause the crank and connecting rod transmission to oscillate, affecting the stability of the mechanism's operation. The oscillation further accelerates wear and reduces service life. Therefore, we propose a highly stable crank-connecting rod mechanism for sewing machines. Utility Model Content

[0005] The purpose of this invention is to provide a highly stable crank-connecting rod mechanism for sewing machines to solve the problems mentioned in the background art.

[0006] To achieve the above object, the utility model provides the following technical solution: a high-stability crank and connecting rod mechanism for a sewing machine, including a support rod. On one side of the bottom of the support rod, there is a sewing machine pedal, and one end of the sewing machine pedal is connected to the support rod through a pedal connecting shaft. On the other side of the support rod, there is a flywheel. The top of the support rod is installed with a transmission crank through a bearing, and one end of the transmission crank is fixed with a crankshaft. The outside of the crankshaft is sleeved with a transmission connecting rod. On the outer parts of the crankshaft on both sides of the transmission connecting rod, a first positioning retaining ring and a second positioning retaining ring are respectively sleeved. And on the outer walls of the first positioning retaining ring and the second positioning retaining ring close to the transmission connecting rod side, there are equally spaced circular grooves, and inside the circular grooves, there are balls. On one side of the crankshaft, there is a fastening crank, and at the end of the fastening crank, there is a threaded hole. One end of the crankshaft is threadedly connected to the threaded hole through an external thread.

[0007] Preferably, the end of the transmission crank far from the crankshaft is fixedly connected to the central position of the flywheel.

[0008] Preferably, the thread direction of the fastening of the threaded hole and the external thread is the same as the rotation direction of the transmission crank.

[0009] Preferably, two groups of supports are fixed on the surface of the sewing machine pedal, and the supports are located at one end of the sewing machine pedal close to the support rod.

[0010] Preferably, the bottom end of the transmission connecting rod extends between the supports and is connected to the supports through a connecting rod connecting shaft.

[0011] Preferably, one end of the ball extends to the outside of the circular groove and is in close contact with the transmission connecting rod.

[0012] Preferably, the transmission crank, the crankshaft, and the fastening crank form a "ji" - shaped structure.

[0013] Preferably, the sides of the first positioning retaining ring and the second positioning retaining ring far from the transmission connecting rod are in close fit with the transmission crank and the fastening crank respectively.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] The connecting rod is mounted on the crankshaft at one end of the transmission crank. A first and second locating retaining rings are installed on the crankshafts on both sides of the connecting rod. The connecting rod is then threaded into the external thread at the end of the crankshaft via a threaded hole at the end of the crank, tightening the crank to secure it to the crankshaft. The tightening crank presses the first locating retaining ring, the connecting rod, and the second locating retaining ring together, thus positioning the connecting rod. When using the sewing machine, the operator steps on the sewing machine pedal, causing it to swing back and forth around the pedal connecting shaft. The sewing machine pedal drives the transmission crank to rotate via the connecting rod and the crankshaft. The transmission crank then drives the flywheel to rotate. The lever mechanism converts the reciprocating linear motion of the operator's foot pedal on the sewing machine into the rotational motion of the flywheel or main shaft. Due to the positioning effect of the first and second positioning retaining rings, the gap at the connection between the transmission connecting rod and the transmission crank is small, reducing loosening. Furthermore, since both the first and second positioning retaining rings make rolling contact with the transmission connecting rod through ball bearings, friction is reduced, thereby reducing wear between the transmission connecting rod and the transmission crank. This crank-connecting rod mechanism reduces the gap between the crank and the connecting rod, making the crank and connecting rod transmission less prone to wobbling, thus improving the stability of the mechanism's operation, reducing wear, and extending its service life. Attached Figure Description

[0016] Figure 1 This is a front view structural diagram of the present utility model;

[0017] Figure 2 This is a side view of the structure of this utility model;

[0018] Figure 3 This is a top-view enlarged structural diagram of the transmission crank of this utility model;

[0019] Figure 4 This is a top view enlarged cross-sectional schematic diagram of the fastening crank of this utility model;

[0020] Figure 5 This is a side enlarged structural schematic diagram of the first positioning retaining ring of this utility model.

[0021] In the diagram: 1. Support rod; 2. Sewing machine pedal; 3. Support; 4. Transmission connecting rod; 5. Fastening crank; 6. Flywheel; 7. Pedal connecting shaft; 8. Connecting rod connecting shaft; 9. Transmission crank; 10. Bearing; 11. Threaded hole; 12. External thread; 13. First positioning retaining ring; 14. Second positioning retaining ring; 15. Crankshaft; 16. Circular groove; 17. Ball bearing. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Therefore, the following detailed description of the embodiments of this utility model provided in the drawings is not intended to limit the scope of the claimed utility model, but merely to illustrate selected embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0024] Please see Figure 1-5 An embodiment of this utility model provides a high-stability crank-connecting rod mechanism for a sewing machine, including a support rod 1, a sewing machine pedal 2 is provided on one side of the bottom of the support rod 1, and one end of the sewing machine pedal 2 is connected to the support rod 1 through a pedal connecting shaft 7. A flywheel 6 is provided on the other side of the support rod 1, and a transmission crank 9 is installed on the top of the support rod 1 through a bearing 10. A crank shaft 15 is fixed to one end of the transmission crank 9, and a transmission connecting rod 4 is sleeved on the outside of the crank shaft 15.

[0025] Specifically, when using the sewing machine, the operator steps on the sewing machine pedal 2, causing it to swing back and forth around the pedal connecting shaft 7. The sewing machine pedal 2 drives the transmission crank 9 to rotate through the transmission connecting rod 4 and the crank shaft 15. The transmission crank 9 drives the flywheel 6 to rotate. Through this crank-connecting rod mechanism, the reciprocating linear motion of the operator stepping on the sewing machine pedal 2 is converted into the rotational motion of the flywheel 6 or the main shaft. This conversion process enables the sewing machine to achieve continuous sewing action. During this process, due to the positioning effect of the first positioning retaining ring 13 and the second positioning retaining ring 14, the gap at the connection between the transmission connecting rod 4 and the transmission crank 9 is small, reducing loosening.

[0026] The crankshafts 15 on both sides of the transmission connecting rod 4 are respectively fitted with a first positioning retaining ring 13 and a second positioning retaining ring 14. The outer walls of the first positioning retaining ring 13 and the second positioning retaining ring 14 near the transmission connecting rod 4 are provided with equally spaced circular grooves 16, and the inside of the circular grooves 16 is provided with balls 17. A fastening crank 5 is provided on one side of the crankshaft 15, and a threaded hole 11 is provided at the end of the fastening crank 5. One end of the crankshaft 15 is threadedly connected to the threaded hole 11 through an external thread 12.

[0027] Specifically, the crank drive mechanism consists of a transmission connecting rod 4, a transmission crank 9, a crankshaft 15, and a fastening crank 5. The transmission connecting rod 4 is installed on the crankshaft 15 at one end of the transmission crank 9. By installing a first positioning retaining ring 13 and a second positioning retaining ring 14 on the crankshaft 15 on both sides of the transmission connecting rod 4, and then threadedly connecting the threaded hole 11 at the end of the fastening crank 5 with the external thread 12 at the end of the crankshaft 15, the fastening crank 5 is screwed and fixed at the end of the crankshaft 15. The fastening crank 5 presses the first positioning retaining ring 13, the transmission connecting rod 4, and the second positioning retaining ring 14, thereby positioning the transmission connecting rod 4.

[0028] One end of the transmission crank 9 away from the crankshaft 15 is fixedly connected to the central position of the flywheel 6.

[0029] The threading direction of the threaded hole 11 and the external thread 12 for fastening is the same as the rotation direction of the transmission crank 9.

[0030] Two groups of supports 3 are fixed on the surface of the sewing machine pedal 2. The supports 3 are located at one end of the sewing machine pedal 2 close to the support rod 1.

[0031] The bottom end of the transmission connecting rod 4 extends between the supports 3 and is connected to the supports 3 through a connecting rod connecting shaft 8.

[0032] One end of the ball 17 extends outside the circular groove 16 and is in close contact with the transmission connecting rod 4. The opening diameter of the circular groove 16 is smaller than the diameter of the ball 17, so that the ball 17 can roll in the circular groove 16 but will not come out of the circular groove 16.

[0033] Furthermore, since both the first positioning retaining ring 13 and the second positioning retaining ring 14 are in rolling contact with the transmission connecting rod 4 through the balls 17, the frictional force is reduced, thereby reducing the wear between the transmission connecting rod 4 and the transmission crank 9. Moreover, the second positioning retaining ring 14 can be separately disassembled and replaced. The threading direction of the threaded hole 11 and the external thread 12 for fastening is the same as the rotation direction of the transmission crank 9, so that the fastening crank 5 is not easily loosened when the transmission crank 9 rotates. This crank and connecting rod mechanism reduces the gap between the crank and the connecting rod, and the crank and connecting rod transmission is not prone to swing, thereby improving the stability of the mechanism operation, reducing the wear condition, and extending the service life.

[0034] The transmission crank 9, the crankshaft 15, and the fastening crank 5 form a "ji" - shaped structure.

[0035] On the sides of the first positioning retaining ring 13 and the second positioning retaining ring 14 away from the transmission connecting rod 4, they are respectively in close fit with the transmission crank 9 and the fastening crank 5.

[0036] In use, the following steps are taken in this embodiment: First, the crank transmission mechanism consists of a transmission connecting rod 4, a transmission crank 9, a crank shaft 15, and a fastening crank 5. The transmission connecting rod 4 is mounted on the crank shaft 15 at one end of the transmission crank 9. A first positioning retaining ring 13 and a second positioning retaining ring 14 are installed on the crank shaft 15 on both sides of the transmission connecting rod 4. The fastening crank 5 is then threadedly connected to the external thread 12 at the end of the crank shaft 15 through the threaded hole 11 at the end of the fastening crank 5, thus tightening and fixing the fastening crank 5 to the end of the crank shaft 15. The fastening crank 5 presses the first positioning retaining ring 13, the transmission connecting rod 4, and the second positioning retaining ring 14, thereby positioning the transmission connecting rod 4. Then, when using the sewing machine, the operator steps on the sewing machine pedal 2, causing it to swing back and forth around the pedal connecting shaft 7. The sewing machine pedal 2 drives the transmission crank 9 to rotate through the transmission connecting rod 4 and the crank shaft 15. The transmission crank 9 drives the flywheel 6 to rotate. The crank-connecting rod mechanism controls the operator's foot movement on the sewing machine pedal. The reciprocating linear motion of plate 2 is converted into the rotational motion of flywheel 6 or main shaft. This conversion process enables the sewing machine to achieve continuous sewing action. During this process, due to the positioning effect of the first positioning retaining ring 13 and the second positioning retaining ring 14, the gap at the connection between the transmission connecting rod 4 and the transmission crank 9 is small, reducing loosening. Furthermore, since the first positioning retaining ring 13 and the second positioning retaining ring 14 are in rolling contact with the transmission connecting rod 4 through the ball bearing 17, the friction is reduced, thereby reducing the wear between the transmission connecting rod 4 and the transmission crank 9. Moreover, the second positioning retaining ring 14 can be replaced separately. The thread direction of the threaded hole 11 and the external thread 12 is the same as the rotation direction of the transmission crank 9, making it difficult for the crank 5 to loosen when the transmission crank 9 rotates. This crank-connecting rod mechanism reduces the gap between the crank and the connecting rod, making the crank and connecting rod transmission less prone to wobbling, thereby improving the stability of the mechanism operation, reducing wear, and extending the service life.

[0037] Obviously, the embodiments described above are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

Claims

1. A high-stability crank-connecting rod mechanism for a sewing machine, comprising a support rod (1), a sewing machine pedal (2) being provided on one side of the bottom of the support rod (1), and one end of the sewing machine pedal (2) being connected to the support rod (1) via a pedal connecting shaft (7), and a flywheel (6) being provided on the other side of the support rod (1), characterized in that, The top of the support rod (1) is installed with a transmission crank (9) through a bearing (10), and one end of the transmission crank (9) is fixed with a crankshaft (15). An outer part of the crankshaft (15) is sleeved with a transmission connecting rod (4). The outer parts of the crankshaft (15) on both sides of the transmission connecting rod (4) are respectively sleeved with a first positioning retaining ring (13) and a second positioning retaining ring (14). The outer walls of the first positioning retaining ring (13) and the second positioning retaining ring (14) on the side close to the transmission connecting rod (4) are provided with equally spaced circular grooves (16), and the circular grooves (16) are internally provided with balls (17). One side of the crankshaft (15) is provided with a fastening crank (5), and a threaded hole (11) is arranged at the end of the fastening crank (5). One end of the crankshaft (15) is threadedly connected with the threaded hole (11) through an external thread (12).

2. The high-stability crank-connecting rod mechanism for a sewing machine according to claim 1, characterized in that: One end of the transmission crank (9) far from the crankshaft (15) is fixedly connected with the center position of a flywheel (6).

3. The high-stability crank-connecting rod mechanism for a sewing machine according to claim 1, characterized in that: The threaded direction of the fastening of the threaded hole (11) and the external thread (12) is the same as the rotating direction of the transmission crank (9).

4. The high-stability crank-connecting rod mechanism for a sewing machine according to claim 1, characterized in that: Two groups of supports (3) are fixed on the surface of the sewing machine pedal (2), and the supports (3) are located at one end of the sewing machine pedal (2) close to the support rod (1).

5. A high-stability crank-connecting rod mechanism for a sewing machine according to claim 1, characterized in that: The bottom end of the transmission connecting rod (4) extends between the supports (3) and is connected with the supports (3) through a connecting rod connecting shaft (8).

6. The high-stability crank-connecting rod mechanism for a sewing machine according to claim 1, characterized in that: One end of the ball (17) extends to the outside of the circular groove (16) and is in close contact with the transmission connecting rod (4).

7. A high-stability crank-connecting rod mechanism for a sewing machine according to claim 1, characterized in that: The transmission crank (9), the crankshaft (15), and the fastening crank (5) form a "Ji" - shaped structure.

8. A high-stability crank-connecting rod mechanism for a sewing machine according to claim 1, characterized in that: The sides of the first positioning retaining ring (13) and the second positioning retaining ring (14) far from the transmission connecting rod (4) are respectively in close fit with the transmission crank (9) and the fastening crank (5).

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