A feed dog motion for a cylinder sewing machine

Abstract

The utility model provides a kind of movement device of cylinder sewing machine feed dog, belong to sewing machine technical field.It solves the problem that existing feed dog movement device is not applicable to cylinder sewing machine.This sewing machine includes the cabinet with long arm, the first end of swing arm is fixed with feed dog, the middle part of swing arm is hinged with long arm, the first end of lifting tooth bar is hinged with long arm, the first end of lifting tooth bar is located directly below the first end of swing arm, lower shaft can drive swing arm swing back and forth around its hinged point by feeding assembly, lower shaft can drive lifting tooth bar swing up and down around its hinged point by lifting tooth assembly, the first end of lifting tooth bar swing upwards can make the first end of swing arm move upwards, swing arm can make the first end of swing arm move downwards under the action of its elasticity.This movement device of cylinder sewing machine feed dog has the advantages of reasonable use of space, smooth movement of cylinder sewing machine feed dog.

Description

Technical Field

[0001] This utility model belongs to the field of sewing machine technology and relates to a motion device for the feed dog of a tubular sewing machine. Background Technology

[0002] A sewing machine is a mechanical device that uses one or more sewing threads to create specific stitches on a material (such as fabric, leather, etc.), allowing one or more layers of material to interweave or sew together. A sewing machine includes a feed dog, whose up-and-down, back-and-forth movement, in conjunction with the presser foot, ensures even movement of the fabric and guarantees neat stitches.

[0003] Existing devices for driving the feed dog to move up and down and back and forth include, for example, a feed dog assembly, thread cutting mechanism, and presser foot lifting mechanism for a sewing machine disclosed in Chinese patent literature [Patent No.: 202110538708.2; Application Publication No.: CN115369580A]. The sewing machine has feed dogs, a feed dog assembly, a thread cutting mechanism, a presser foot lifting mechanism, an up-and-down lifting power source, and a front-and-back feed power source. The feed dog assembly includes a front-and-back feed assembly and an up-and-down lifting feed assembly. The up-and-down lifting power source drives crank one and crank two of the front-and-back feed assembly to indirectly realize the back-and-forth reciprocating movement of the feed dog, and drives the presser foot lifting cam and top plate of the presser foot lifting mechanism to realize the presser foot lifting action. The front-and-back feed power source drives multi-stage cam one and multi-stage cam two of the up-and-down lifting feed assembly to indirectly realize the up-and-down reciprocating movement of the feed dog, and drives the thread cutting cam and thread cutting transmission bracket of the thread cutting mechanism to realize the thread cutting action.

[0004] In this type of sewing machine feed dog assembly, the front and rear feed power sources reciprocate the feed dog's movement, while the up and down lifting power source reciprocates the feed dog's movement, thus completing the feed dog's feeding action. However, this type of sewing machine includes a base plate and a sewing head mounted on the base plate. The base plate is rectangular, with the feed dog located at its left end. Sufficient mounting space exists below the left end of the base plate, allowing the up / down lifting power source and the front / rear feed power source to be installed below the left end to drive the feed dog's movement. But for tube sewing machines, which include a long, straight cylindrical arm, the feed dog is installed at the left end (the head end) of the arm. The space at the head end of the arm is limited, and there is insufficient space to install the front / rear feed power source and the up / down lifting power source. Therefore, the drive mechanism of this type of feed dog assembly is not suitable for tube sewing machines. Summary of the Invention

[0005] The purpose of this utility model is to address the aforementioned problems in the existing technology by proposing a motion device for the feed dog of a tubular sewing machine. The technical problem to be solved is how to make reasonable use of space to ensure smooth movement of the feed dog in the tubular sewing machine.

[0006] The objective of this utility model can be achieved through the following technical solution: A motion device for the feed dog of a tubular sewing machine, the sewing machine including a machine housing with a long arm, characterized in that the motion device includes a swing arm and a feed dog lever located in the long arm, and a lower shaft, a feed assembly, and a feed dog lever assembly located in the tail end of the machine housing, the swing arm being elastic, the feed dog being fixedly connected to the first end of the swing arm, the middle part of the swing arm being hinged to the long arm, the first end of the feed dog lever being hinged to the long arm, and the first end of the feed dog lever being located directly below the first end of the swing arm. The lower shaft is connected to the tail end of the swing arm via the feeding assembly. The lower shaft can drive the swing arm to swing back and forth around its own hinge point via the feeding assembly. The lower shaft is connected to the tail end of the lifting rod via the lifting tooth assembly. The lower shaft can drive the lifting rod to swing up and down around its own hinge point via the lifting tooth assembly. The upward swing of the head end of the lifting rod can cause the swing arm to undergo elastic deformation and move the head end of the swing arm upward. The swing arm returns to its original shape under the action of its own elastic force, which can move the head end of the swing arm downward.

[0007] The tubular sewing machine includes a long arm, with its first end used for sewing and its second end connected to the tail end of the machine housing. The long arm is relatively slender and has limited internal space; therefore, the lower shaft, feed assembly, and feed dog assembly are placed in the tail end of the machine housing, while only the swing arm and feed dog lever are installed in the long arm. This efficient use of space allows for a rational arrangement of the feed dog's movement mechanism. Both the swing arm and feed dog lever are elongated, with their lengths approximating those of the long arm, meaning the swing arm is longer. The middle of the swing arm is hinged to the long arm. The lower shaft, through the feed assembly, causes the swing arm to swing back and forth, thus moving the feed dog back and forth. The lower shaft, via the lifting assembly, causes the lifting rod to swing up and down. The swing arm is elastic; when the lifting rod's tip swings upward, lifting the tip of the swing arm, the swing arm undergoes elastic deformation, causing its tip to move upward, thus lifting the feed dog. When the lifting rod's tip swings downward, the swing arm returns to its original position under its own elastic force, resetting its tip downward, thus pressing the feed dog down, completing the feed dog's up-and-down movement. In other words, by rotating the lower shaft, the feeding assembly drives the swing arm to swing back and forth, while the lifting assembly simultaneously drives the lifting rod to swing up and down, causing the lifting rod to push the tip of the swing arm to swing up and down, ultimately achieving the back-and-forth and up-and-down movement of the feed dog. This ensures smooth feed dog movement in the tube sewing machine and, in conjunction with the presser foot, facilitates feeding. In actual operation, the feed dog only needs to be lifted by 0.6mm, which means that the amount of deformation required for the swing arm is very small. The swing arm still has sufficient rigidity. When a 1kg upward force is applied to the head end of the swing arm, it can be lifted by 0.8mm, which is perfectly suitable for this motion device.

[0008] In the aforementioned motion device for the feed dog of a tubular sewing machine, the swing arm has a hinge hole in its middle, through which a rivet sleeve is fixedly connected. A rotating shaft is fixedly connected to the long arm, and the rivet sleeve is rotatably fitted around the rotating shaft. A rotating sleeve made of engineering plastic is provided between the rivet sleeve and the rotating shaft. This structure allows the swing arm to hinge with the long arm, and the rotating sleeve, made of engineering plastic, provides sufficient rigidity while also offering elastic deformation. The rotating sleeve can absorb the deformation caused by the swing arm being lifted, preventing damage at the hinge point between the swing arm and the long arm, and improving the stability of the motion device.

[0009] In the aforementioned feed dog mechanism of a tubular sewing machine, the middle and end of the feed dog lever are located below the side of the swing arm, and the middle part of the feed dog lever is a downwardly concave curved section. This structure prevents the feed dog lever from getting stuck with the swing arm when it swings up and down, making reasonable use of space and allowing for a rational arrangement of the motion mechanism.

[0010] In the aforementioned motion device for the feed dog of a tubular sewing machine, the feed dog lifting rod includes a lifting lever and a lifting connecting rod. The lifting lever is hinged to the long arm, and the lifting connecting rod is connected to the feed dog assembly. The lifting lever and the lifting connecting rod are detachably connected by bolts. When the feed dog needs to move up and down, the lifting lever and the lifting connecting rod are connected by bolts. When only the feed dog needs to move back and forth, the bolts can be removed to disconnect the lifting lever and the lifting connecting rod, preventing the lifting lever from working and thus preventing it from lifting the feed dog. Therefore, it is not necessary to remove the lifting rod.

[0011] In the aforementioned feed dog movement device of a tubular sewing machine, the machine housing has a guide groove arranged vertically, and a guide block is sleeved on the tail end of the feed dog lever. The guide block is located in the guide groove and can move up and down along the groove wall. This structure ensures the feed dog lever swings up and down, improving its stability and thus enhancing the stability of the movement device.

[0012] In the aforementioned feed dog mechanism of a tubular sewing machine, the feed assembly is entirely located at the bottom of the tail end of the machine housing. This structure makes efficient use of the internal space of the machine housing.

[0013] In the aforementioned motion device for the feed dog of a tubular sewing machine, the feeding assembly includes a feeding connecting rod, a feeding swing frame, a feeding swing rod, a feeding shaft, and a feeding intermediate rod. One end of the feeding connecting rod is provided with a feeding eccentric wheel, and a feeding bearing is provided between the feeding connecting rod and the feeding eccentric wheel. The other end of the feeding connecting rod is connected to the feeding swing frame. The lower shaft passes through the feeding eccentric wheel. The feeding swing rod is sleeved on the feeding shaft. One end of the feeding swing rod is connected to the feeding swing frame, and the other end of the feeding swing rod is connected to one end of the feeding intermediate rod. The other end of the feeding intermediate rod is connected to the tail end of the swing arm. A first joint bearing is provided between the feeding swing rod and the feeding intermediate rod, and a second joint bearing is provided between the feeding intermediate rod and the tail end of the swing arm. The lower shaft rotates, driving the feeding eccentric wheel and feeding connecting rod to swing the feeding swing frame, which in turn drives the feeding swing arm to swing. This causes the feeding intermediate rod to translate horizontally, thus realizing the forward and backward rotation of the swing arm. The placement of the first and second joint bearings prevents the feeding assembly from jamming during linkage, ensuring that the horizontal translation of the feeding intermediate rod is converted into the forward and backward swing of the swing arm. In actual production, the feeding bearings can be omitted to reduce costs.

[0014] In the aforementioned feed dog motion device of a tubular sewing machine, the feed dog assembly includes a feed dog crank and a feed dog eccentric wheel. One end of the feed dog crank is connected to the tail end of the feed dog rod, and a third joint bearing is provided between the feed dog crank and the tail end of the feed dog rod. The feed dog eccentric wheel is located at the other end of the feed dog crank, and a feed dog bearing is provided between the feed dog crank and the feed dog eccentric wheel. The lower shaft passes through the feed dog eccentric wheel. Rotation of the lower shaft drives the feed dog crank to swing via the feed dog eccentric wheel. The third joint bearing, in conjunction with a guide block and guide groove, allows the swing of the feed dog crank to be converted into the up-and-down swing of the feed dog rod. In actual production, the feed dog bearing can also be omitted to reduce costs.

[0015] Compared with the prior art, the motion device for the feed dog of a tubular sewing machine provided by this utility model has the following advantages:

[0016] 1. The long arm of this tube sewing machine is relatively slender and the internal space is limited. Therefore, the lower shaft, feeding assembly and lifting dog assembly are placed at the tail end of the machine housing. Only the swing arm and lifting dog rod need to be installed in the long arm. This makes reasonable use of space and makes the movement device of the feed dog more reasonable.

[0017] 2. This tube sewing machine rotates its lower shaft, which drives the swing arm to swing back and forth via the feeding assembly and simultaneously drives the lifting rod to swing up and down via the lifting assembly. This causes the lifting rod to push the head of the swing arm to swing upward. When the swing arm returns to its original shape under its own elasticity, it drives the head to swing downward, thus realizing the back-and-forth and up-and-down movement of the feed dog and making the feed dog move smoothly.

[0018] 3. The swing arm of this tube sewing machine is elastic and has sufficient rigidity, and the rotating sleeve is elastic and has sufficient rigidity, so that the swing arm can rotate back and forth and swing up and down at the same time, thereby realizing the back-and-forth and up-and-down movement of the feed dog. The structure is simple and the design is ingenious. Attached Figure Description

[0019] Figure 1 This is a structural diagram of this tube sewing machine.

[0020] Figure 2 This is a schematic diagram of the arrangement of the feed dog motion device of this tubular sewing machine.

[0021] Figure 3 This is a schematic diagram of the overall structure of the feed dog motion device of this tubular sewing machine.

[0022] Figure 4 This is a cross-sectional view of the hinge joint between the swing arm and the housing of this motion device.

[0023] In the diagram, 1. Housing; 1a. Long arm; 1b. Guide groove; 2. Swing arm; 21. Hinge hole; 3. Tooth lifting rod; 31. Tooth lifting lever; 32. Tooth lifting connecting rod; 33. Bolt; 34. Guide block; 4. Lower shaft; 5. Feeding assembly; 51. Feeding connecting rod; 52. Feeding swing frame; 53. Feeding swing arm; 54. Feeding shaft; 55. Feeding intermediate rod; 56. Feeding eccentric wheel; 57. Feeding bearing; 58. First joint bearing; 59. Second joint bearing; 6. Tooth lifting assembly; 61. Tooth lifting crank; 62. Tooth lifting eccentric wheel; 63. Third joint bearing; 64. Tooth lifting bearing; 7. Feeding tooth; 8. Riveting sleeve; 9. Rotating shaft; 10. Rotating sleeve. Detailed Implementation

[0024] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0025] like Figure 1 , Figure 2 , Figure 3 As shown, the tube sewing machine includes a housing 1 with a long arm 1a and a motion device for the feed dog 7. The motion device includes a swing arm 2, a feed dog lever 3, a lower shaft 4, a feed assembly 5, and a feed dog lever 6. The swing arm 2 and the feed dog lever 3 are both located in the long arm 1a, and the lower shaft 4, the feed assembly 5, and the feed dog lever 6 are all located as a whole in the bottom of the tail end of the housing 1.

[0026] The swing arm 2 is elastic, with a feed tooth 7 fixedly connected to its head end, and the middle part of the swing arm 2 hinged to the long arm 1a. Specifically, as shown... Figure 4As shown, the middle part of the swing arm 2 has a hinge hole 21, and a rivet sleeve 8 is fixedly connected through the hinge hole 21. A rotating shaft 9 is fixedly connected in the long arm 1a. The rivet sleeve 8 is rotatably sleeved on the outside of the rotating shaft 9. A rotating sleeve 10 made of engineering plastic is provided between the rivet sleeve 8 and the rotating shaft 9.

[0027] The tail end of the swing arm 2 extends into the tail end of the housing 1 and is connected to the feeding assembly 5. Specifically, the feeding assembly 5 includes a feeding connecting rod 51, a feeding swing frame 52, a feeding swing rod 53, a feeding shaft 54, and a feeding intermediate rod 55. One end of the feeding connecting rod 51 is provided with a feeding eccentric wheel 56, and a feeding bearing 57 is provided between the feeding connecting rod 51 and the feeding eccentric wheel 56. The other end of the feeding connecting rod 51 is connected to the feeding swing frame 52. The lower shaft 4 passes through the feeding eccentric wheel 56. The feeding swing rod 53 is sleeved on the feeding shaft 54. One end of the feeding swing rod 53 is connected to the feeding swing frame 52, and the other end of the feeding swing rod 53 is connected to one end of the feeding intermediate rod 55. The other end of the feeding intermediate rod 55 is connected to the tail end of the swing arm 2. A first joint bearing 58 is provided between the feeding swing rod 53 and the feeding intermediate rod 55, and a second joint bearing 59 is provided between the feeding intermediate rod 55 and the tail end of the swing arm 2.

[0028] The first end of the lifting rod 3 is hinged to the long arm 1a. The first end of the lifting rod 3 is located directly below the first end of the swing arm 2. The middle and tail ends of the lifting rod 3 are located on the side and below the swing arm 2. The middle part of the lifting rod 3 is a downwardly concave curved section.

[0029] The tail end of the swing arm 2 extends into the tail end of the housing 1 and is connected to the feeding assembly 5. Specifically, the tooth lifting assembly 6 includes a tooth lifting crank 61 and a tooth lifting eccentric wheel 62. One end of the tooth lifting crank 61 is connected to the tail end of the tooth lifting rod 3. A third joint bearing 63 is provided between the tooth lifting crank 61 and the tail end of the tooth lifting rod 3. The tooth lifting eccentric wheel 62 is located in the other end of the tooth lifting crank 61. A tooth lifting bearing 64 is provided between the tooth lifting crank 61 and the tooth lifting eccentric wheel 62. The lower shaft 4 passes through the tooth lifting eccentric wheel 62.

[0030] The lifting rod 3 includes a lifting lever 31 and a lifting connecting rod 32. The lifting lever 31 is hinged to the long arm 1a, and the lifting connecting rod 32 is connected to the lifting assembly 6. The lifting lever 31 and the lifting connecting rod 32 are detachably connected by bolts 33. The housing 1 has a guide groove 1b arranged in a vertical direction. A guide block 34 is sleeved on the tail end of the lifting rod 3. The guide block 34 is located in the guide groove 1b and can move up and down along the groove wall of the guide groove 1b.

[0031] During operation, the lower shaft 4 drives the swing arm 2 to swing back and forth around its own hinge point through the feeding assembly 5. At the same time, the lower shaft 4 drives the lifting rod 3 to swing up and down around its own hinge point through the lifting assembly 6. The upward swing of the lifting rod 3 can cause the swing arm 2 to undergo elastic deformation and move the head of the swing arm 2 upward. Under the action of its own elastic force, the swing arm 2 returns to its original shape and moves the head of the swing arm 2 downward, thereby realizing the up and down and back and forth movement of the feeding tooth.

[0032] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0033] Although this document frequently uses terms such as housing 1, long arm 1a, guide groove 1b, swing arm 2, hinge hole 21, lifting rod 3, lifting lever 31, lifting connecting rod 32, bolt 33, guide block 34, lower shaft 4, feeding assembly 5, feeding connecting rod 51, feeding swing frame 52, feeding swing rod 53, feeding shaft 54, feeding intermediate rod 55, feeding eccentric wheel 56, feeding bearing 57, first joint bearing 58, second joint bearing 59, lifting assembly 6, lifting crank 61, lifting eccentric wheel 62, third joint bearing 63, lifting bearing 64, feeding tooth 7, riveting sleeve 8, rotating shaft 9, rotating sleeve 10, etc., the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any additional limitation would contradict the spirit of this utility model.

Claims

1. A movement device for the feed dog of a cylinder sewing machine, the sewing machine comprising a casing (1) having a long arm (1a), characterized in that, The motion device includes a swing arm (2) and a lifting rod (3) located in the long arm (1a), and a lower shaft (4), a feeding assembly (5), and a lifting rod assembly (6) located in the tail end of the housing (1). The swing arm (2) is elastic, and a feeding tooth (7) is fixedly connected to the head end of the swing arm (2). The middle part of the swing arm (2) is hinged to the long arm (1a). The head end of the lifting rod (3) is hinged to the long arm (1a). The head end of the lifting rod (3) is located directly below the head end of the swing arm (2). The lower shaft (4) is connected to the tail end of the swing arm (2) through the feeding assembly (5). The lower shaft (4) is connected to the end of the feeding assembly (5). The lower shaft (4) can drive the swing arm (2) to swing back and forth around its own hinge point through the feeding assembly (5). The lower shaft (4) is connected to the tail end of the lifting rod (3) through the lifting assembly (6). The lower shaft (4) can drive the lifting rod (3) to swing up and down around its own hinge point through the lifting assembly (6). The upward swing of the head end of the lifting rod (3) can cause the swing arm (2) to undergo elastic deformation and move the head end of the swing arm (2) upward. The swing arm (2) returns to its original shape under the action of its own elastic force and can move the head end of the swing arm (2) downward.

2. A motion device for a feed dog of a cylinder-type sewing machine according to claim 1, wherein The swing arm (2) has a hinge hole (21) in the middle, and a rivet sleeve (8) is fixedly connected through the hinge hole (21). A rotating shaft (9) is fixedly connected in the long arm (1a). The rivet sleeve (8) is rotatably sleeved on the rotating shaft (9). A rotating sleeve (10) made of engineering plastic is provided between the rivet sleeve (8) and the rotating shaft (9).

3. A motion device for a feed dog of a cylinder-type sewing machine according to claim 1, wherein The middle and tail ends of the lifting rod (3) are located below the side of the swing arm (2), and the middle part of the lifting rod (3) is a downwardly concave curved section.

4. A motion device for a feed dog of a cylinder lockstitch sewing machine according to claim 1 or 2 or 3, characterized in that, The tooth-lifting rod (3) includes a tooth-lifting lever (31) and a tooth-lifting connecting rod (32). The tooth-lifting lever (31) is hinged to the long arm (1a), and the tooth-lifting connecting rod (32) is connected to the tooth-lifting assembly (6). The tooth-lifting lever (31) and the tooth-lifting connecting rod (32) are detachably connected by bolts (33).

5. A motion device for a feed dog of a cylinder lockstitch sewing machine according to claim 1 or 2 or 3, characterized in that, The housing (1) has a guide groove (1b) arranged in a vertical direction. The tail end of the lifting rod (3) is fitted with a guide block (34). The guide block (34) is located in the guide groove (1b) and can move up and down along the groove wall of the guide groove (1b).

6. A motion device for a feed dog of a cylinder lockstitch sewing machine according to claim 1 or 2 or 3, characterized in that, The feeding assembly (5) is located at the bottom of the tail end of the housing (1).

7. A motion device for a feed dog of a cylinder lockstitch sewing machine according to claim 1 or 2 or 3, characterized in that, The feeding assembly (5) includes a feeding connecting rod (51), a feeding swing frame (52), a feeding swing rod (53), a feeding shaft (54), and a feeding intermediate rod (55). One end of the feeding connecting rod (51) is provided with a feeding eccentric wheel (56), and a feeding bearing (57) is provided between the feeding connecting rod (51) and the feeding eccentric wheel (56). The other end of the feeding connecting rod (51) is connected to the feeding swing frame (52). The lower shaft (4) passes through the feeding eccentric wheel (56), and the feeding swing rod (53) is sleeved on... On the feeding shaft (54), one end of the feeding swing rod (53) is connected to the feeding swing frame (52), the other end of the feeding swing rod (53) is connected to one end of the feeding intermediate rod (55), the other end of the feeding intermediate rod (55) is connected to the tail end of the swing arm (2), a first joint bearing (58) is provided between the feeding swing rod (53) and the feeding intermediate rod (55), and a second joint bearing (59) is provided between the feeding intermediate rod (55) and the tail end of the swing arm (2).

8. A motion device for a feed dog of a cylinder lockstitch sewing machine according to claim 1 or 2 or 3, characterized in that, The tooth lifting assembly (6) includes a tooth lifting crank (61) and a tooth lifting eccentric wheel (62). One end of the tooth lifting crank (61) is connected to the tail end of the tooth lifting rod (3). A third joint bearing (63) is provided between the tooth lifting crank (61) and the tail end of the tooth lifting rod (3). The tooth lifting eccentric wheel (62) is located in the other end of the tooth lifting crank (61). A tooth lifting bearing (64) is provided between the tooth lifting crank (61) and the tooth lifting eccentric wheel (62). The lower shaft (4) passes through the tooth lifting eccentric wheel (62).

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