Locking mechanism in feed dog adjusting device on sewing machine

Abstract

The utility model provides a locking mechanism in a feed dog adjusting device on a sewing machine, and belongs to the technical field of sewing machines. The technical problem that an existing locking mechanism is low in stability is solved. The locking mechanism in the feed dog adjusting device on the sewing machine comprises a synchronous check ring and a locking swing rod, the synchronous check ring is fixedly arranged on a main shaft in a sleeving mode and located at one end of a first eccentric wheel, the synchronous check ring and a second eccentric wheel are fixed in the circumferential direction, and a plurality of positioning grooves are formed in the circumferential surface of the synchronous check ring in the circumferential direction; the middle section of the locking swing rod is hinged to one end of the first eccentric wheel and located on one side of the synchronous check ring, one end of the locking swing rod is provided with a positioning protruding part capable of being embedded into the positioning groove, an elastic piece is arranged between one end of the locking swing rod and the first eccentric wheel, the other end of the locking swing rod is an unlocking end, and the unlocking rod can be pressed on the unlocking end of the locking swing rod when extending. And when the unlocking rod extends, the first eccentric wheel can be circumferentially fixed. The utility model has the advantage of more stable use.

Description

TECHNICAL FIELD

[0001] The utility model belongs to sewing machine technical field relates to a sewing machine upper feed dog adjusting device, especially a locking mechanism in sewing machine upper feed dog adjusting device. BACKGROUND

[0002] The sewing machine upper feed dog is moved in the front and back and up and down directions to realize cloth feeding, the front and back displacement of the sewing machine upper feed dog is related to the density of the sewing thread, and the front and back displacement of the sewing machine upper feed dog needs to be adjusted according to the process requirements of different cloths and different clothes, the sewing machine upper feed dog adjusting device is a device for adjusting the front and back displacement of the sewing machine upper feed dog, and the adjustment of the displacement is mainly realized by adjusting the swing amplitude of the sewing feed shaft.

[0003] At present, the sewing machine upper feed dog adjusting device mainly realizes the adjustment of the swing amplitude of the sewing feed shaft through a double cam structure, for example, a sewing machine cloth feeding adjusting mechanism disclosed in Chinese patent literature (application number 202010009134.5) and a sewing machine cloth feeding adjusting mechanism (application number 201811404195.0), in order to realize the fixing and separation between the two cams, a sliding block is generally used to slide along the groove to realize unlocking and locking, and the sliding block will be jammed or stuck when moving along the groove due to the force direction deviating from the groove, so that the stability is low, and the use is not convenient; the sliding block cannot be positioned on the sliding block during assembly, and the spring and the ratchet wheel need to be assembled in place, and then the sliding block can be positioned in the groove, so that the assembly is more complex, and the production cost is higher. UTILITY MODEL CONTENTS

[0004] The utility model aims at the above problems existing in the prior art, and provides a locking mechanism in a sewing machine upper feed dog adjusting device, and the technical problem to be solved by the utility model is to provide a locking mechanism that is more stable to use.

[0005] The utility model can achieve the purpose by the following technical schemes.

[0006] The application discloses a locking mechanism in a feed dog adjusting device of a sewing machine, and the feed dog adjusting device of the sewing machine comprises a first eccentric wheel connected to a main shaft, a second eccentric wheel sleeved on the first eccentric wheel and an unlocking lever telescopically arranged on a machine shell, and the locking mechanism comprises a synchronous stop ring and a locking swing lever, the synchronous stop ring is fixedly sleeved on the main shaft and located at one end of the first eccentric wheel, the synchronous stop ring is fixed in a circumferential direction of the second eccentric wheel, a plurality of positioning grooves are arranged on a circumferential surface of the synchronous stop ring, the middle section of the locking swing lever is hinged at one end of the first eccentric wheel and located at one side of the synchronous stop ring, one end of the locking swing lever is provided with a positioning protrusion capable of being embedded into the positioning grooves, an elastic element is arranged between the one end of the locking swing lever and the first eccentric wheel and used for pressing the one end of the locking swing lever towards the synchronous stop ring, and the other end of the locking swing lever is an unlocking end, when the unlocking lever is elongated, the unlocking end of the locking swing lever can be pressed to make the one end of the locking swing lever be lifted relative to the synchronous stop ring, and when the unlocking lever is elongated, the first eccentric wheel can be fixed in the circumferential direction.

[0007] One end of the connecting rod is sleeved on the second eccentric wheel, the other end of the connecting rod is connected to one end of a crank of the feed dog shaft, the first eccentric wheel and the second eccentric wheel are driven to rotate by the main shaft, the connecting rod is driven to swing up and down, the feed dog shaft is driven to rotate back and forth, and the feed dog is driven to move back and forth.

[0008] The second eccentric wheel and the synchronous stop ring rotate synchronously, when the positioning protrusion is embedded into the positioning grooves, the synchronous stop ring and the first eccentric wheel rotate synchronously through the locking swing lever, so that the first eccentric wheel, the second eccentric wheel, the synchronous stop ring and the main shaft rotate synchronously. When it is necessary to adjust the displacement of the feed dog, the main shaft is rotated to align the unlocking end of the unlocking lever and the locking swing lever, the unlocking lever is stretched to the unlocking end and is pressed on the unlocking end, the locking swing lever is rotated, the positioning protrusion of the locking swing lever is separated from the positioning grooves of the synchronous stop ring, the synchronous stop ring and the first eccentric wheel are separated in the circumferential direction, the first eccentric wheel is fixed in the circumferential direction, the synchronous stop ring and the second eccentric wheel rotate when the main shaft is rotated, the first eccentric wheel remains fixed, the first eccentric wheel and the second eccentric wheel rotate relatively, the eccentric amount of the connecting rod relative to the main shaft is adjusted, the swing amplitude of the crank is adjusted, the unlocking lever is retracted after the adjustment, the positioning protrusion of the locking swing lever is repositioned to the synchronous stop ring and is embedded into the corresponding positioning grooves under the action of the elastic element, the synchronous stop ring and the first eccentric wheel are relatively fixed in the circumferential direction, and the adjustment of the displacement of the feed dog is completed. The simple structure of the synchronous stop ring and the locking swing lever can realize the unlocking and locking between the first eccentric wheel and the second eccentric wheel relative to the main shaft, the production cost is reduced, the hinged locking swing lever does not have the problem of being stuck, and the use stability is higher.

[0009] In the locking mechanism of the feed dog adjusting device of the sewing machine, the positioning slots are gear slots formed on the synchronous stop ring, and the positioning protrusion of the locking swing lever is a gear tooth capable of engaging with the gear slots.

[0010] In the locking mechanism of the feed dog adjusting device of the sewing machine, the first eccentric wheel comprises a first cam portion and a mounting ring portion located at one end of the first cam portion, the edge of the mounting ring portion is provided with a stop edge, the elastic member is a spring, one end of the spring abuts against the stop edge, and the other end of the spring abuts against one end of the locking swing lever provided with a positioning protrusion.

[0011] In the locking mechanism of the feed dog adjusting device of the sewing machine, a clearance gap is formed on the stop edge, the clearance gap is opposite to the unlocking end of the locking swing lever, and the unlocking lever can pass through the clearance gap. When the unlocking lever passes through the clearance gap, the first eccentric wheel is prevented from rotating circumferentially, and the unlocking end of the locking swing lever is also pressed.

[0012] In the locking mechanism of the feed dog adjusting device of the sewing machine, the middle segment of the locking swing lever is hinged to the mounting ring portion through an axial screw. The axial screw can directly mount the locking swing lever to the first eccentric wheel, thereby improving the structural stability, simplifying the mounting steps, reducing the production cost, and improving the efficiency.

[0013] In the locking mechanism of the feed dog adjusting device of the sewing machine, the second eccentric wheel comprises a second cam portion and a connecting ring portion located at the second cam portion, a sliding groove is formed on the connecting ring portion in the radial direction, a sliding block is slidably connected in the sliding groove, and a connecting shaft is connected between the sliding block and the synchronous stop ring. When the first eccentric wheel and the second eccentric wheel rotate relative to each other, the sliding block can move along the sliding groove, and the connecting shaft can fix the sliding block and the synchronous stop ring in the circumferential direction, so that the second eccentric wheel and the synchronous stop ring rotate synchronously.

[0014] In the locking mechanism of the feed dog adjusting device of the sewing machine, one end of the connecting shaft is integrally formed with the synchronous stop ring, and a connecting hole one is formed on the sliding block. The other end of the connecting shaft is arranged in the connecting hole one.

[0015] As another case, in the locking mechanism of the feed dog adjusting device of the sewing machine, one end of the connecting shaft is integrally formed with the sliding block, a connecting hole two is formed on the synchronous stop ring, and the other end of the connecting shaft is arranged in the connecting hole two.

[0016] In the locking mechanism of the feed dog adjusting device of the sewing machine, the mounting ring portion and the connecting ring portion abut against each other, the mounting ring portion is provided with an arc-shaped hole, and the connecting shaft passes through the arc-shaped hole. When the first eccentric wheel and the second eccentric wheel rotate relative to each other, the connecting shaft can move along the arc-shaped hole.

[0017] The locking mechanism of the feeding dog adjusting device of the sewing machine has the advantages of higher stability and easier installation compared with the prior art.

[0018] The locking mechanism of the feeding dog adjusting device of the sewing machine has the advantages of higher stability and easier installation compared with the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a top view of the embodiment one assembled in the sewing machine.

[0020] Figure 2 is a perspective view of the embodiment one assembled in the sewing machine.

[0021] Figure 3 is an exploded view of the adjusting device in the embodiment one.

[0022] Figure 4 is a perspective view of the adjusting device in the embodiment one.

[0023] Figure 5 is a left view of the first eccentric wheel and the second eccentric wheel when assembled.

[0024] Figure 6 is a perspective view of the second eccentric wheel.

[0025] Figure 7 is a perspective view of the first eccentric wheel.

[0026] Figure 8 is a perspective view of the synchronous stop ring.

[0027] Figure 9 is a perspective view of the locking swing lever.

[0028] In the figure, 1, main shaft; 11, flat key groove; 12, connecting rod; 13, upper feeding shaft; 14, crank; 15, upper feeding dog; 16, machine housing; 2, first eccentric wheel; 21, first cam part; 22, mounting ring part; 221, arc-shaped hole; 23, stop edge; 231, let-out notch; 3, second eccentric wheel; 31, second cam part; 32, connecting ring part; 33, mounting groove; 331, compression spring sheet; 34, sliding groove; 35, sliding block; 351, connecting hole one; 4, unlocking lever; 41, button; 5, synchronous stop ring; 51, gear groove; 52, connecting shaft; 6, locking swing lever; 61, gear tooth; 62, unlocking end; 63, limiting groove; 64, shaft position screw; 65, spring. DETAILED DESCRIPTION

[0029] The utility model discloses the following specific embodiments are combined with the drawings, and the technical scheme of the utility model is further described, but the utility model is not limited to these embodiments.

[0030] Embodiment one

[0031] As Figure 1 And Figure 2 As shown in the sewing machine, the feed dog 15 adjusting device includes connecting rod 12, the first eccentric wheel 2 connected on the main shaft 1, the second eccentric wheel 3 on the first eccentric wheel 2 and the unlocking lever 4 set on the shell 16, the first eccentric wheel 2 includes the first cam portion 21 and the mounting ring portion 22 at one end of the first cam portion 21, the second eccentric wheel 3 includes the second cam portion 31 and the connecting ring portion 32 at the second cam portion 31, the second cam portion 31 is sleeved on the first cam portion 21, one end of the connecting rod 12 is sleeved on the second cam portion 31, the other end of the connecting rod 12 is connected to one end of the crank 14 of the feed shaft 13, the first eccentric wheel 2 and the second eccentric wheel 3 are driven to rotate by the main shaft 1, the up-and-down swing of the connecting rod 12 is realized, the feed shaft 13 is driven to rotate back and forth by the crank 14, the feed dog 15 is connected with the feed shaft 13, and the feed shaft 13 can drive the feed dog 15 to move back and forth.

[0032] As Figures 1 to 9 As shown in the locking mechanism, the locking mechanism includes the synchronous blocking ring 5 and the locking swing lever 6, the synchronous blocking ring 5 is fixedly sleeved on the main shaft 1 and located at one end of the first eccentric wheel 2, the synchronous blocking ring 5 is fixed in the circumferential direction of the second eccentric wheel 3, a plurality of positioning grooves are formed on the circumferential surface of the synchronous blocking ring 5 in the circumferential direction, the middle segment of the locking swing lever 6 is hinged at one end of the first eccentric wheel 2 and located at one side of the synchronous blocking ring 5, one end of the locking swing lever 6 is provided with a positioning convex portion capable of being embedded into the positioning groove, and an elastic member is arranged between one end of the locking swing lever 6 and the first eccentric wheel 2 and used for pressing one end of the locking swing lever 6 towards the synchronous blocking ring 5, preferably, the plurality of positioning grooves in the embodiment are a plurality of gear grooves 51 formed in the synchronous blocking ring 5, the positioning convex portion of the locking swing lever 6 is a gear tooth 61 capable of being engaged with the gear groove 51, the gear tooth 61 is provided with a plurality of gear teeth and arranged in an arc shape and opposite to the plurality of gear grooves 51, the gear tooth 61 is engaged with the gear groove 51 under the action of the elastic member, the other end of the locking swing lever 6 is an unlocking end 62, and the unlocking lever 4 can be pressed against the unlocking end 62 of the locking swing lever 6 so that the locking swing lever 6 swings and prevents the first eccentric wheel 2 from rotating in the circumferential direction.

[0033] The middle section of the locking swing lever 6 is hinged to the mounting ring part 22 through an axial screw 64, the edge of the mounting ring part 22 is provided with a stop edge 23, the elastic member is a spring 65, one end of the spring 65 abuts against the stop edge 23, the locking swing lever 6 is provided with a limiting groove 63 on the side of the end provided with the positioning protrusion, facing the side of the spring 65, the other end of the spring 65 abuts against in the limiting groove 63. The stop edge 23 is annular, a gap 231 is formed in the stop edge 23, the width of the gap 231 matches the diameter of the unlocking lever 4, the unlocking lever 4 can just pass through the gap 231 and collide with the stop edge 23 when the first eccentric wheel 2 rotates; the unlocking lever 4 extends inwardly to pass through the gap 231 and press the unlocking end 62 of the locking swing lever 6 when the button 41 is pressed, so that the locking swing lever 6 rotates around the axial screw 64 to realize that the gear teeth 61 are separated from the gear groove 51, at this time, the unlocking lever 4 abuts against the stop edge 23 to limit the rotation of the first eccentric wheel 2; the unlocking lever 4 retracts outwardly and is separated from the gap 231 after the button 41 is released.

[0034] A sliding groove 34 is formed in the connecting ring part 32 in the radial direction, a sliding block 35 is slidably connected in the sliding groove 34, a connecting shaft 52 is connected between the sliding block 35 and the synchronous stop ring 5, one end of the connecting shaft 52 is integrally formed with the synchronous stop ring 5, an arc-shaped hole 221 is formed in the mounting ring part 22, the connecting shaft 52 passes through the arc-shaped hole 221, a connecting hole one 351 is formed in the sliding block 35, the other end of the connecting shaft 52 passes through the connecting hole one 351. When the first eccentric wheel 2 and the second eccentric wheel 3 rotate relative to each other, the sliding block 35 can move along the sliding groove 34, the connecting shaft 52 can fix the sliding block 35 and the synchronous stop ring 5 in the circumferential direction, so that the second eccentric wheel 3 and the synchronous stop ring 5 rotate synchronously.

[0035] A pressing spring piece 331 is arranged between the first eccentric wheel 2 and the second eccentric wheel 3, specifically, an installation groove 33 is formed in the inner wall of the second eccentric wheel 3, the pressing spring piece 65 is located in the installation groove 33, a threaded hole is further formed in the installation groove 33, a bolt is screwed in the installation groove 33 and abuts against the pressing spring piece 65 to press the pressing spring piece 65 against the outer peripheral wall of the first cam part 21. The pressing spring piece 331 can increase the sliding friction, thereby stabilizing the eccentricity of the first eccentric wheel 2 and the second eccentric wheel 3 during high-speed operation.

[0036] A flat key groove 11 is formed in the main shaft 1, the synchronous stop ring 5 is sleeved at the flat key groove 11 of the main shaft 1, a bolt is screwed on the synchronous stop ring 5, and the end of the bolt abuts against in the flat key groove 11. Through the structure, the main shaft 1 and the synchronous stop ring 5 are fixed in the circumferential direction.

[0037] The second eccentric wheel 3 and the synchronous blocking ring 5 rotate synchronously, and when the positioning protrusion is embedded in the positioning groove, the synchronous blocking ring 5 and the first eccentric wheel 2 rotate synchronously through the locking swing lever 6, so that the first eccentric wheel 2, the second eccentric wheel 3, the synchronous blocking ring 5 and the main shaft 1 rotate synchronously. When the displacement size of the back-and-forth movement of the upper feeding tooth 15 needs to be adjusted, the main shaft 1 is rotated to align the unlocking end 62 of the locking swing lever 6, the unlocking lever 4 is pressed to the unlocking end 62 and is pressed tightly on the unlocking end 62, the locking swing lever 6 is rotated, the positioning protrusion of the locking swing lever 6 is separated from the positioning groove of the synchronous blocking ring 5, at this time the synchronous blocking ring 5 is separated from the first eccentric wheel 2 in the circumferential direction and the first eccentric wheel 2 is fixed in the circumferential direction, the synchronous blocking ring 5 and the second eccentric wheel 3 rotate when the main shaft 1 is rotated, but the first eccentric wheel 2 remains fixed, the relative rotation of the first eccentric wheel 2 and the second eccentric wheel 3 is realized, the purpose of adjusting the eccentric amount of the connecting rod 12 relative to the main shaft 1 is achieved, and the adjustment of the swing amplitude of the crank 14 is realized; after the adjustment is completed, the unlocking lever 4 is retracted, the positioning protrusion of the locking swing lever 6 is re-embedded in the corresponding positioning groove under the action of the elastic element, the synchronous blocking ring 5 and the first eccentric wheel 2 are re-fixed relative to each other in the circumferential direction, and the adjustment of the displacement size of the back-and-forth movement of the upper feeding tooth 15 is completed.

[0038] Embodiment two

[0039] The structure and principle of this embodiment are basically the same as those of embodiment one, and the difference lies in that one end of the connecting shaft is integrally formed with the sliding block, and a connecting hole two is formed in the synchronous blocking ring, and the other end of the connecting shaft is arranged in the connecting hole two.

[0040] Embodiment three

[0041] The structure and principle of this embodiment are basically the same as those of embodiment one, and the difference lies in that the elastic element is a torsion spring, the torsion spring is sleeved on the shaft position screw, one end of the torsion spring acts on the mounting ring part, and the other end of the torsion spring acts on one end of the locking swing lever provided with the positioning protrusion, and the torsion spring presses one end of the locking swing lever provided with the positioning protrusion towards the synchronous blocking ring.

[0042] Embodiment four

[0043] The structure and principle of this embodiment are basically the same as those of embodiment one, and the difference lies in that the main shaft and the synchronous blocking ring are connected through spline cooperation, and the circumferential fixing of the main shaft and the synchronous blocking ring is realized.

[0044] Embodiment five

[0045] The structure and principle of this embodiment are basically the same as those of embodiment one, and the difference lies in that the plurality of positioning grooves are a plurality of tapered holes formed in the synchronous blocking ring, the positioning protrusion of the locking swing lever is a tapered protrusion, and the tapered protrusion can be clamped into the tapered hole.

[0046] Embodiment six

[0047] The embodiment is basically same as the structure and principle of the embodiment one, and the difference is that the unlocking rod is fixed with a positioning rod in parallel, the peripheral surface of the mounting ring part is provided with a positioning hole, the positioning hole and the unlocking end of the locking swing rod are located at the same side, the positioning rod will extend to the mounting ring part and be inserted into the positioning hole when the unlocking rod is elongated, and the first eccentric wheel is fixed in the circumferential direction through the cooperation of the positioning rod and the positioning hole.

[0048] The specific embodiments described herein are merely illustrative of the spirit of the present application. Those skilled in the art of the present application can make various modifications or supplements to the described specific embodiments or replace them with similar ways, but will not deviate from the spirit of the present application or exceed the scope defined by the appended claims.

Claims

1. A locking mechanism in a feed dog adjusting device of a sewing machine, the feed dog adjusting device of the sewing machine comprising a first eccentric wheel (2) connected to a main shaft (1), a second eccentric wheel (3) sleeved on the first eccentric wheel (2), and an unlocking lever (4) telescopically arranged on a machine housing (16), characterized in that, The locking mechanism comprises a synchronous stop ring (5) and a locking swing lever (6), the synchronous stop ring (5) is fixed on the main shaft (1) and located at one end of the first eccentric wheel (2), the synchronous stop ring (5) is fixed in the circumferential direction of the second eccentric wheel (3), a plurality of positioning grooves are arranged on the circumferential surface of the synchronous stop ring (5), the middle section of the locking swing lever (6) is hinged at one end of the first eccentric wheel (2) and located at one side of the synchronous stop ring (5), one end of the locking swing lever (6) is provided with a positioning protrusion which can be embedded in the positioning groove, an elastic element is arranged between one end of the locking swing lever (6) and the first eccentric wheel (2) to press one end of the locking swing lever (6) towards the synchronous stop ring (5), the other end of the locking swing lever (6) is an unlocking end (62), the unlocking lever (4) can press on the unlocking end (62) of the locking swing lever (6) when it is elongated, so that one end of the locking swing lever (6) is lifted relative to the synchronous stop ring (5), and the first eccentric wheel (2) is circumferentially fixed when the unlocking lever (4) is elongated.

2. The locking mechanism in a sewing machine upper feed dog adjusting device according to claim 1, wherein The plurality of positioning grooves are a plurality of gear grooves (51) arranged on the synchronous stop ring (5), and the positioning protrusion of the locking swing lever (6) is a gear tooth (61) which can engage with the gear groove (51).

3. The locking mechanism in a sewing machine upper feed dog adjustment device according to claim 1, wherein The middle section of the locking swing lever (6) is hinged to the mounting ring part (22) through an axle position screw (64).

4. The locking mechanism in the upper feed dog adjusting device of the sewing machine according to claim 1 or 2 or 3, characterized in that, The first eccentric wheel (2) comprises a first cam part (21) and a mounting ring part (22) located at one end of the first cam part (21), the edge of the mounting ring part (22) is provided with a stop edge (23), the elastic element is a spring (65), one end of the spring (65) abuts against the stop edge (23), and the other end of the spring (65) abuts against one end of the locking swing lever (6) provided with the positioning protrusion.

5. The locking mechanism in a sewing machine upper feed dog adjustment device according to claim 4, wherein The stop edge (23) is provided with a gap notch (231), the gap notch (231) is opposite to the unlocking end (62) of the locking swing lever (6), and the unlocking lever (4) can pass through the gap notch (231).

6. The locking mechanism in a sewing machine upper feed dog adjustment device according to claim 4, wherein The second eccentric wheel (3) comprises a second cam part (31) and a connecting ring part (32) located at the second cam part (31), the connecting ring part (32) is provided with a sliding groove (34) in the radial direction, the sliding groove (34) is slidably connected with a sliding block (35), and the sliding block (35) and the synchronous stop ring (5) are connected with a connecting shaft (52).

7. The locking mechanism in a sewing machine upper feed dog adjustment device according to claim 6, wherein One end of the connecting shaft (52) is integrally formed with the synchronous stop ring (5), the sliding block (35) is provided with a connecting hole one (351), and the other end of the connecting shaft (52) is arranged in the connecting hole one (351).

8. The locking mechanism in a sewing machine upper feed dog adjustment device according to claim 6, wherein One end of the connecting shaft (52) is integrally formed with the sliding block (35), the synchronous stop ring (5) is provided with a connecting hole two, and the other end of the connecting shaft (52) is arranged in the connecting hole two.

9. The locking mechanism in a sewing machine upper feed dog adjustment device according to claim 6, wherein The mounting ring part (22) and the connecting ring part (32) abut against each other, the mounting ring part (22) is provided with an arc-shaped hole (221), and the connecting shaft (52) passes through the arc-shaped hole (221).

10. The locking mechanism in the upper feed dog adjusting device of the sewing machine according to claim 1 or 2 or 3, characterized in that, The first eccentric wheel (2) and the second eccentric wheel (3) are provided with a compression spring sheet (331).

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