Device for adjusting the tilt of the presser foot and feed dog of a serging machine

Abstract

The utility model provides a device of presser foot lifting and feed tooth inclination adjustment of overlock sewing machine, which solves the following problems compared with prior art: separate driving equipment is needed in presser foot lifting and descending feeding, the cost and price of sewing machine increase, and these driving equipment cannot cope with the inclination adjustment of differential feed tooth. The device of presser foot lifting and feed tooth inclination adjustment of overlock sewing machine has a stepping motor (5), a feed tooth inclination adjustment component (3) connected with the stepping motor (5), a presser foot lifting component (4) connected with the stepping motor (5), and a control device of the stepping motor (5).

Description

Technical Field

[0001] This utility model relates to a device for lifting the presser foot and adjusting the tilt of the feed teeth in an overlock sewing machine. In this utility model, "front and back" refers to the front-to-back direction in the fabric feeding direction, and "left and right" refers to the left-to-right direction when viewing the sewing machine from the front. Additionally, "up and down" refers to the up-and-down direction of the sewing machine. Background Technology

[0002] As for the presser foot device in existing overlock sewing machines, it is known to have a structure with a solenoid, which is a drive device for raising the presser foot (for example, see Patent Document 1). Additionally, as for the feed device in existing overlock sewing machines, it is known to have a structure with a cylinder, which is a drive device for lowering the main feed teeth and differential feed teeth from the upper surface of the needle plate (for example, see paragraphs 0032, 0033, and 0034 of Patent Document 2). Figure 10 , Figure 11 , Figure 12 ).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Publication No. 07-067512

[0006] Patent Document 2: Japanese Patent Application Publication No. 2013-066640 (paragraphs 0032, 0033, 0034 and...) Figure 10 , Figure 11 , Figure 12 ) Utility Model Content

[0007] The problem to be solved by utility models

[0008] In existing technology, when a sewing machine stops after one stitch, the needle waits at the top dead center, as do the main feed teeth and differential feed teeth. Then, when the presser foot is raised using the drive mechanism to place the fabric onto the needle plate, the main feed teeth and differential feed teeth, which fly out from the upper surface of the needle plate, act as an obstacle, causing the fabric to float slightly before being placed in the correct sewing position. For small pieces of fabric such as collars and short sleeves, this slight floating before placement in the correct position, if not matching the position, is repeated, resulting in repetitive work that requires little force but some time. For larger pieces of fabric, such as the sides of trousers or the hem of curtains, the weight of the fabric increases, and the repetitive nature of the work results in extra time and significant fatigue. To alleviate these burdens, additional drive devices are used to lower the main feed teeth and differential feed teeth from the upper surface of the needle plate, so that the main feed teeth and differential feed teeth do not become obstacles and the fabric can be loaded by sliding laterally from the needle plate.

[0009] Thus, additional drive devices are required for the so-called presser foot lifting drive (which raises the presser foot when the sewing machine stops) and the so-called descending feed drive (which lowers the main feed teeth and differential feed teeth from the upper surface of the needle plate), becoming a major reason for the increased cost and price of sewing machines. Furthermore, solenoids and cylinders are frequently used in the descending feed and presser foot lifting drive devices, driving continuously from the top dead center to the bottom dead center. Depending on the sewing conditions, for example, adjusting the tilt of the differential feed teeth to tilt the forward direction upward to increase the force of conveying the fabric when there are thick sections such as steps or bands caused by overlapping in the middle of the fabric, or adjusting the tilt of the differential feed teeth to tilt the forward direction downward to simply reduce the stitch spacing to prevent unraveling, the descending feed drive device cannot handle these situations, requiring additional components or devices.

[0010] The present invention addresses the problem of providing a device for adjusting the presser foot lifting and feed tooth tilt of an overlock sewing machine, which solves the following problems: the above-mentioned presser foot lifting and lowering feed require separate drive devices, which increases the cost and price of the sewing machine, and it is impossible to use these drive devices to adjust the tilt of the differential feed teeth.

[0011] Methods for solving problems

[0012] To achieve the above objectives, the utility model described in technical solution 1 is a device for lifting the presser foot and adjusting the tilt of the feed teeth in an overlock sewing machine. The overlock sewing machine includes: a needle that reciprocates up and down; an upper looper and a lower looper that move in conjunction with the needle and reciprocate left and right; a needle plate disposed on the sewing machine body and supporting the fabric from below; a presser foot that supports the fabric from above; and a main feed tooth and a differential feed tooth that move up and down and back and forth. The device for lifting the presser foot and adjusting the tilt of the feed teeth includes: a stepper motor; a feed tooth tilt adjustment member that is connected to the stepper motor; a presser foot lifting member that is connected to the stepper motor; and a control device for the stepper motor.

[0013] To achieve the above objectives, the utility model described in technical solution 2, based on the device for adjusting the presser foot lifting and feed tooth tilt of the overlock sewing machine described in technical solution 1, is characterized in that the device for adjusting the presser foot lifting and feed tooth tilt comprises: a drive crank that fixes the presser foot lifting component to the motor shaft of the stepper motor; a presser foot lifting drive linkage, one end of which is connected to the drive crank; a presser foot lifting drive rod that is connected to the other end of the presser foot lifting drive linkage; an intermediate crank whose swing end is connected to the swing center of the presser foot lifting drive rod, and swings together when the engaging part of the presser foot lifting drive rod is in contact with the intermediate crank and pressed; and a pivot pin that passes through the swing center of the intermediate crank. The device includes a shaft hole configured to allow the intermediate crank to swing; a presser foot lifting linkage, one end of which is connected to the other swing end of the intermediate crank that is not connected to the presser foot lifting actuator; a presser foot lifting rod, the swing end of which is connected to the other end of the presser foot lifting linkage, and a shaft hole located at the center of the swing that allows it to swing through the presser foot platform shaft; a presser foot lifting shaft crank, which is fixed to the presser foot platform shaft on the side of the presser foot lifting rod; and a presser foot height adjusting screw, which is inserted into a threaded hole on the presser foot lifting shaft crank and fixed with the front end of the screw protruding. When the engaging part of the presser foot lifting rod is engaged with the presser foot height adjusting screw and pressed, the presser foot lifting shaft crank and the presser foot lifting rod swing together.

[0014] To achieve the above objectives, the utility model described in technical solution 3 is based on the device for adjusting the presser foot lifting and feed tooth tilt of the overlock sewing machine described in technical solution 2, characterized in that the device for adjusting the presser foot lifting and feed tooth tilt includes a presser foot height sensor component for detecting the vertical position of the presser foot.

[0015] To achieve the above objectives, the utility model described in technical solution 4, based on the device for lifting the presser foot and adjusting the feed tooth tilt of the overlock sewing machine described in any one of technical solutions 1 to 3, is characterized in that the device for lifting the presser foot and adjusting the feed tooth tilt comprises: a drive cam that fixes the feed tooth tilt adjusting member to the motor shaft of the stepper motor; a feed tooth tilt adjusting rod that swings in conjunction with the drive cam; a feed tooth tilt adjusting connecting rod, one end of which is connected to the feed tooth tilt adjusting rod; and an eccentric shaft crank that is connected to the other end of the feed tooth tilt adjusting connecting rod and is fixed at the center of swing to the body shaft of the eccentric shaft provided on the sewing machine body.

[0016] To achieve the above objectives, the utility model described in technical solution 5 is based on the device for lifting the presser foot and adjusting the tilt of the feed tooth in the overlock sewing machine described in technical solution 4. The device for lifting the presser foot and adjusting the tilt of the feed tooth has a feed tooth tilt adjustment area, a presser foot lifting area, and a transition area on the cam profile of the drive cam and the feed tooth tilt adjustment rod.

[0017] Utility Model Effect

[0018] According to the present invention, a device for adjusting the presser foot lifting and feed tooth tilt addresses the problems of increased sewing machine cost and price due to the need for different drive devices for presser foot lifting and lowering feed, and the inability of these drive devices to handle the tilt adjustment of differential feed teeth. The overlock sewing machine includes: a needle that reciprocates up and down; upper and lower loopers that reciprocate left and right in conjunction with the needle; a needle plate disposed on the sewing machine body and supporting the fabric from below; a presser foot that supports the fabric from above; and main feed teeth and differential feed teeth that move up and down and back and forth. The device for adjusting the presser foot lifting and feed tooth tilt includes a stepper motor; a feed tooth tilt adjustment member linked to the stepper motor; a presser foot lifting member linked to the stepper motor; and a control device for the stepper motor. This allows the drive devices for presser foot lifting and lowering feed to be unified, thus reducing the increase in sewing machine cost and price, and enables the tilt adjustment of differential feed teeth via the feed tooth tilt adjustment member. Attached Figure Description

[0019] Figure 1 This is a perspective view of the sewing machine applied to this invention, viewed from the left rear. The positive X-axis represents the right direction, the positive Y-axis represents the rear direction, and the positive Z-axis represents the upward direction.

[0020] Figure 2 This is a top view of the feed tooth tilt adjustment component of the device for lifting the presser foot and adjusting the tilt of the feed teeth in the sewing machine applied to this utility model.

[0021] Figure 3 This is a left-side view of the feed tooth tilt adjustment component of the device for lifting the presser foot and adjusting the tilt of the feed teeth in the sewing machine applied to this utility model.

[0022] Figure 4 This is a top view of the presser foot lifting component of the presser foot lifting and feed tooth tilting adjustment device of the sewing machine applied to this utility model.

[0023] Figure 5 This is a left-side view of the presser foot lifting component of the presser foot lifting and feed tooth tilting adjustment device of the sewing machine applied to this utility model.

[0024] Figure 6This is a left-side view showing the operation of the feed tooth tilt adjustment component of the presser foot lifting and feed tooth tilt adjustment device applied to the sewing machine of this utility model.

[0025] Figure 7 This is a left-side view showing the first stage of the feed tooth tilt adjustment member and the presser foot lifting member of the sewing machine applied to this utility model, which are part of the device for adjusting the presser foot lifting and the feed tooth tilt.

[0026] Figure 8 This is a left-side view showing the second stage of the feed tooth tilt adjustment member and the presser foot lifting member of the sewing machine applied to this utility model.

[0027] Figure 9 This is a left-side view showing the third stage of the feed tooth tilt adjustment member and the presser foot lifting member of the sewing machine applied to this utility model.

[0028] Figure 10 This is a left-side view showing the fourth stage of the presser foot lifting and feed tooth tilting adjustment device applied to the sewing machine of this utility model, including the feed tooth tilting adjustment member and the presser foot lifting member.

[0029] Figure 11 This is a left-side view showing the fifth stage of the presser foot lifting and feed tooth tilting adjustment device applied to the sewing machine of this utility model, including the feed tooth tilting adjustment member and the presser foot lifting member.

[0030] Figure 12 This is a left-side view of the presser foot height sensor component and the pneumatic presser foot pressing component of the device for adjusting the presser foot lifting and feed tooth tilt of the sewing machine applied to this utility model.

[0031] Explanation of reference numerals in the attached figures

[0032] 1. Sewing machine

[0033] 2. Feed mechanism

[0034] 3. Feed tooth tilt adjustment component

[0035] 4. Lift the component with the presser foot.

[0036] 5 stepper motors

[0037] 6. Pressure Foot Height Sensor Component

[0038] 7. Pneumatic press foot component

[0039] 10. Sewing machine body

[0040] 11 needle plate

[0041] 12 presser feet

[0042] 13. Foot presser

[0043] 14. Presser foot bar

[0044] 15. Presser foot spring

[0045] 16 Presser foot joint

[0046] 17. Presser foot axis

[0047] 18. Presser foot bearing

[0048] 20 Main feed teeth

[0049] 21 Differential feed gear

[0050] 22 Main feed table

[0051] 23 Differential feed stage

[0052] 24. Front corner block of the feed table

[0053] 25 Corner block behind the feed table

[0054] 26 Eccentric Shaft

[0055] 30 Active Cam

[0056] 31 Feed gear tilt adjustment rod

[0057] 32 shaft pins

[0058] 33 Feed gear tilt adjustment linkage

[0059] 34 Eccentric Shaft Crank

[0060] 40 Active crank

[0061] 41. Lift the active linkage with the presser foot.

[0062] 42. Lift the lever with the presser foot.

[0063] 43. Intermediate crank

[0064] 44 shaft pins

[0065] 45. Lift the connecting rod with the presser foot.

[0066] 46. ​​Press down with the foot and lift the lever.

[0067] 47. Lift the crankshaft using the presser foot.

[0068] 48. Presser foot height adjustment screw

[0069] 49. Adjusting screw for bottom stop under the pressure foot

[0070] 50 Motor mounting base

[0071] 60 Hall Sensor

[0072] 61 Permanent Magnets

[0073] 70 cylinders

[0074] 71 Bracket

[0075] 72 Double-arm crank

[0076] 260 Eccentric Shaft

[0077] 261. Body shaft

[0078] 300 feed tooth tilt adjustment area

[0079] 301 Presser foot lifting area

[0080] 302 Transition Zone

[0081] 310 Cam Follower

[0082] 420 (The locking part where the presser foot lifts the drive lever)

[0083] 430 (Intermediate crank) engagement part

[0084] 460 (The locking part of the lever with the presser foot). Detailed Implementation

[0085] The following is based on Figures 1 to 12 An example of an embodiment of this utility model will be described. Figure 1 This is a perspective view of the sewing machine as seen from the left rear, applicable to this invention. The positive X-axis represents the right direction, the positive Y-axis represents the rear direction, and the positive Z-axis represents the upward direction. As is known, the sewing machine 1 is equipped with a needle (not shown) that moves up and down, a needle plate 11 disposed on the sewing machine body 10, and an upper curved needle (not shown) and a lower curved needle (not shown) that clamp the needle near the needle plate 11 and move back and forth, working together to sew. The presser foot 12 can move up and down and is positioned on the upper surface of the needle plate 11 in a state of being pressed from above, clamping the fabric being sewn and pressing it from above for holding it.

[0086] The presser foot 13 is arranged in a branching manner behind the needle, with a shaft portion at its lower front end extending in the left-right direction and inserted into a bearing portion located in the middle of the presser foot 12, thereby allowing the presser foot 12 to swing from above. Thus, if the front end of the presser foot 13 rises, the presser foot 12 rises together, and the presser foot 12 swings around its bearing portion. The presser foot lever 14 is tilted slightly upwards and backwards along its length, and holds the presser foot 13 from above at a position slightly behind the front end of the presser foot 13. The presser foot lever spring 15 presses down from the upper end of the presser foot lever 14, thereby pressing the presser foot 13 and the presser foot 12. The presser foot joint 16 is connected to the branching rear end of the presser foot 13 in a manner that allows the presser foot 13 to swing laterally. The presser foot shaft 17 is oriented axially in the left-right direction and is oscillatingly connected to the presser foot connector 16 at its left end. The presser foot bearing 18 is located at the rear of the sewing machine body 10 and oscillatingly supports the middle part of the presser foot shaft 17.

[0087] Thus, the presser foot 12 is pressed against the needle plate 11 from above by the presser foot lever spring 15 without any external force, and remains stationary on the needle plate 11 by being held by the presser foot platform 13 via the presser foot lever 14. Furthermore, if the presser foot 12 is lifted upwards, it swings upwards around the presser foot platform axis 17 at the rear of the presser foot platform 13. In addition, if the presser foot lever 14 is raised against the force of the presser foot lever spring 15, the presser foot platform 13 and the presser foot 12 are released from the hold of the presser foot lever 14 above, and can swing laterally at the connection point with the presser foot platform joint 16 at its rear end.

[0088] The main spindle (not shown) is rotatably mounted on the sewing machine body 10 with its axis pointing left and right, and is driven by a servo motor or similar device. The rotation of the main spindle is transmitted through various mechanical elements, thus becoming the driving force for the up-and-down movement of the needle on the left, the reciprocating motion of the upper and lower loopers, and the movement of the feed mechanism 2. The feed mechanism 2 applies a periodic motion, which combines up-and-down and back-and-forth movements, to the main feed table 22, the main feed gear 20 located in front of the differential feed table 23, and the differential feed gear 21, for example, an elliptical motion when viewed from the side.

[0089] During fabric feeding during sewing, the fabric moves backward a distance equal to the stitch spacing each time the needle and the upper and lower loopers form a stitch. This is achieved as follows: as the needle moves upward from the fabric located on the upper surface of the needle plate 11, the rear main feed tooth 20 and the front differential feed tooth 21 rise from below the slots in the needle plate 11 to the upper surface of the needle plate 11, supporting the fabric from below and pressing it down with the lower surface of the presser foot 12, while moving backward. When the needle descends again to pierce the fabric, the main feed tooth 20 and the differential feed tooth 21 have retracted downward from the needle plate 11, and sewing is performed with the fabric held by the lower surface of the presser foot 12 and the upper surface of the needle plate 11. The stitch spacing is approximately determined by the distance the main feed tooth 20 and the differential feed tooth 21 move back and forth on the upper surface of the needle plate 11.

[0090] The main feed stage 22 and the differential feed stage 23 are plate-shaped, with the main feed stage 22 positioned on the right and the differential feed stage 23 positioned on the left, slidably arranged facing each other. The main feed stage 22 and the differential feed stage 23 have two U-shaped forks at their rear and front, respectively. Inside these forks, cuboid upper and lower corner blocks 24 at the rear and 25 at the front are slidably arranged and guided on their upper and lower surfaces. A through-hole is formed in the center of each of the upper and lower corner blocks 24 and 25, extending in the left-right direction. The upper and lower corner blocks 24 at the front are inserted into their through-holes at an eccentric shaft (not shown) located to the left of the main shaft's center. As the main shaft rotates, the upper and lower corner blocks 24 move up and down and back and forth, and the main feed stage 22 and the differential feed stage 23, guided on their upper and lower surfaces, move up and down accordingly.

[0091] Behind the main shaft, the eccentric shaft 26 protrudes to the left, inserting the shaft portion on the machine body side into the shaft hole provided in the sewing machine body 10. The eccentric shaft portion of the eccentric shaft 26 is inserted into the upper and lower corner blocks 25 behind the feed table. Thus, by rotating the main shaft, the upper and lower corner blocks 24 in front of the feed table move up and down, and the front of the main feed table 22 and the differential feed table 23 move up and down. Behind the main feed table 22 and the differential feed table 23, the upper and lower corner blocks 25 behind the feed table restrict the up and down movement and give it an inclination.

[0092] By rotating and fixing the eccentric shaft 26, the main feed table 22 and the differential feed table 23 are given various inclinations as follows: the main feed teeth 20 and the differential feed teeth 21 remain approximately horizontal only near the top dead center and are inclined in other positions; the main feed teeth 20 and the differential feed teeth 21 remain approximately horizontal when their upper ends are aligned with the upper surface of the needle plate 11 in the path from the front dead center to the top dead center and are inclined in other positions; the main feed teeth 20 and the differential feed teeth 21 are always inclined upwards in the movement from the front dead center through the top dead center to the rear dead center; the main feed teeth 20 and the differential feed teeth 21 are always inclined downwards in the movement from the front dead center through the top dead center to the rear dead center; and the so-called downward feed state, in which the front is further inclined downwards significantly and the upper ends of the main feed teeth 20 and the differential feed teeth 21 do not protrude from the upper surface of the needle plate 11 even at the top dead center.

[0093] Figure 2 This is a top view of the feed tooth tilt adjustment component of the device for lifting the presser foot and adjusting the feed tooth tilt of the sewing machine applied to this utility model. Figure 3 This is a left-side view of the feed tooth tilt adjustment member of the device for adjusting the presser foot lift and feed tooth tilt of the sewing machine according to this invention. The device includes a stepper motor 5, a feed tooth tilt adjustment member 3 linked to the stepper motor 5, a control device (not shown) for the stepper motor 5, and an input device (not shown). The stepper motor 5 is driven to the left and is threadedly fixed to a motor mounting base 50 located at the rear of the sewing machine body 10. The stepper motor 5 has a control device and an input device, and can operate during or before / after sewing. The input device can be a known device based on an LCD panel and buttons, or a touch panel, etc.

[0094] In this embodiment, the feed gear tilt adjustment member 3 includes: an active cam 30 fixedly connected to the motor shaft of the stepper motor 5; a feed gear tilt adjustment rod 31 that swings in conjunction with the active cam 30; a pin 32 inserted into a shaft hole provided at the swing center of the feed gear tilt adjustment rod 31 and provided on the motor mounting base 50; a feed gear tilt adjustment connecting rod 33, one end of which is connected to the swing end of the feed gear tilt adjustment rod 31; and an eccentric shaft crank 34 connected to the other end of the feed gear tilt adjustment connecting rod 33 and fixedly connected at the swing center to the machine body shaft portion 261 (the aforementioned machine body side shaft portion) of the eccentric shaft 26 provided on the sewing machine body 10.

[0095] A cam follower 310 is provided in the middle of the feed gear tilt adjustment rod 31. The cam profile of the driving cam 30 and the cam follower 310 are pressed together by a spring (not shown), thereby linking them. Alternatively, the cam follower 310 can be omitted, and the driving cam 30 can directly abut against the middle of the feed gear tilt adjustment rod 31.

[0096] As described above, if the motor shaft of the stepper motor 5 rotates, the feed gear tilt adjustment rod 31 is oscillated by the active cam 30, the eccentric shaft crank 34 is oscillated by the feed gear tilt adjustment linkage 33, and the eccentric shaft portion 260 (the aforementioned eccentric shaft portion) of the eccentric shaft 26 oscillates, thereby applying various tilts to the main feed gear 20 and the differential feed gear 21.

[0097] Figure 4 This is a top view of the presser foot lifting component of the device for lifting the presser foot and adjusting the inclination of the feed teeth in the sewing machine applied to this utility model. Figure 5 This is a left-side view of the presser foot lifting member of the device for adjusting the presser foot lifting and feed tooth tilt of the sewing machine according to this invention. The device for adjusting the presser foot lifting and feed tooth tilt includes a presser foot lifting member 4 that is linked to a stepper motor 5. In this embodiment, the presser foot lifting member 4 includes: a drive crank 40, which is fixed to the motor shaft of the stepper motor 5; a presser foot lifting drive linkage 41, one end of which is connected to the drive crank 40; a presser foot lifting drive rod 42, which is connected to the other end of the presser foot lifting drive linkage 41; an intermediate crank 43, the swing end of which is connected to the swing center of the presser foot lifting drive rod 42, and swings together when the engaging part 420 of the presser foot lifting drive rod 42 engages with the intermediate crank 43 and is pressed; and a shaft pin 44, which is inserted into the shaft hole at the swing center of the intermediate crank 43, and the intermediate crank 43 is swingably positioned.

[0098] In addition, in this embodiment, the presser foot lifting member 4 includes: a presser foot lifting connecting rod 45, one end of which is connected to the other swing end of the unconnected presser foot lifting active rod 42 of the intermediate crank 43; a presser foot lifting rod 46, the swing end of which is connected to the other end of the presser foot lifting connecting rod 45, and a shaft hole provided at the swing center that can swing through the presser foot platform shaft 17; a presser foot lifting shaft crank 47, which is fixed to the presser foot platform shaft 17 on the side of the presser foot lifting rod 46; and a presser foot height adjusting screw 48, which is inserted through the threaded hole provided in the presser foot lifting shaft crank 47 and fixed in such a way that the front end of the screw protrudes, and when pressed by engaging with the engaging part 460 of the presser foot lifting rod 46, the presser foot lifting shaft crank 47 and the presser foot lifting rod 46 swing together.

[0099] exist Figure 4 In this state, the presser foot 12 is pressed against the needle plate 11 from above by the presser foot lever spring 15 and remains stationary. When the drive crank 40 rotates from this point, the presser foot lifting drive linkage 41 moves downward, and the presser foot lifting drive lever 42 swings downward. The middle part of the presser foot lifting drive lever 42 (located in...) Figure 4The engaging part 420 (near the swing center) engages with and presses against the middle crank 43 from above, causing the middle crank 43 to swing downwards. Simultaneously, the presser foot lifting linkage 45, connected to the other swing end of the middle crank 43, moves downwards, causing the presser foot lifting lever 46 to swing downwards. The engaging part 460 of the presser foot lifting lever 46 is located in front of the presser foot height adjusting screw 48. By swinging the presser foot lifting lever 46 downwards, it engages with the presser foot height adjusting screw 48 and presses it backwards, causing the presser foot lifting shaft crank 47 to swing downwards, and the presser foot platform shaft 17 to swing (in... Figure 4 (Observed from the center, the direction is counterclockwise). Furthermore, by utilizing the swing of the presser foot pivot 17, the presser foot 12 swings upward via the presser foot platform 13. The drive to lift the presser foot is thus performed.

[0100] Furthermore, when the presser foot 12 is lifted upwards while the drive crank 40 is stationary, the presser foot platform shaft 17 swings via the presser foot platform 13 and the presser foot platform connector 16. At this time, although the presser foot lifting shaft crank 47, which is fixed to the presser foot platform shaft 17, swings, the protruding screw tip of the presser foot height adjusting screw 48, which is fixed to the presser foot lifting shaft crank 47, moves away from the engaging portion 460 of the presser foot lifting rod 46 ( Figure 4 The presser foot lifting lever 46 is not pressed because the movement is counterclockwise (as observed in the middle). Therefore, during sewing, even if the main feed tooth 20 and the differential feed tooth 21 move upward to lift the fabric and lift the presser foot 12 upward, the engaging part 460 of the presser foot lifting lever 46 is not pressed, so the movement is unrestricted.

[0101] exist Figure 4 In the current state, the presser foot bottom dead center adjusting screw 49 is inserted into the threaded hole provided in the motor mounting base 50. The front end of the screw protrudes and is fixed, engaging with the engagement portion 430 of the intermediate crank 43. When the presser foot bottom dead center adjusting screw 49 is further tightened from this point, slightly increasing the protrusion of the front end of the screw, the engagement portion 430 of the intermediate crank 43 is pressed, the intermediate crank 43 swings, the presser foot lifting linkage 45 moves downward, the presser foot lifting lever 46 swings downward, engages with the presser foot height adjusting screw 48 and presses backward, the presser foot lifting shaft crank 47 swings downward, and the presser foot 12 is lifted upward. Thus, the presser foot 12 can be kept in a slightly floating state without pressing down, such as when there is no fabric between the presser foot 12 and the needle plate 11 when forming an empty loop, thus suppressing damage and noise caused by the collision between the presser foot 12 and the needle plate 11.

[0102] Figure 6This is a left-side view showing the operation of the feed tooth tilt adjustment member in the device for adjusting the presser foot lift and feed tooth tilt of the sewing machine applied to this invention. In this embodiment, the drive cam 30 has a feed tooth tilt adjustment region 300, a presser foot lift region 301, and a transition region 302 on its cam profile linked to the feed tooth tilt adjustment rod 31. Figure 6 In the diagram, following the order of top, center, and bottom, we see the stepper motor 5 rotating clockwise as observed in the diagram. With the cam follower 310 of the feed gear tilt adjustment rod 31 in contact with the feed gear tilt adjustment area 300 of the drive cam 30, the swing end of the feed gear tilt adjustment rod 31 rises. At this time, as the feed gear tilt adjustment linkage 33 rises, the eccentric shaft crank 34 swings clockwise as observed in the diagram, and the eccentric shaft 26 rotates. Therefore, as described above, various tilts are assigned to the main feed gear 20 and the differential feed gear 21.

[0103] When the active cam 30 from Figure 6 When the lower diagram is rotated further clockwise, the cam follower 310 of the feed gear tilt adjustment lever 31 extends beyond the feed gear tilt adjustment area 300 of the driving cam 30 and comes into contact with the presser foot lifting area 301. The cam profile in the presser foot lifting area 301 becomes a circumferential region sharing a center with the rotation center of the driving cam 30, in which the cam follower 310 does not move up or down. If the driving cam 30 rotates further, it extends beyond the presser foot lifting area 301 and becomes a transition area 302. The transition area 302 is formed to smoothly connect the cam profiles of the feed gear tilt adjustment area 300 and the presser foot lifting area 301.

[0104] Figure 7 This is a left-side view showing the first stage of the feed tooth tilt adjustment member and the presser foot lifting member of the device for adjusting the presser foot lift and feed tooth tilt in the sewing machine of this utility model. In the first stage, it shows the cam follower 310 of the feed tooth tilt adjustment rod 31 engaging at the middle of the feed tooth tilt adjustment area 300 of the driving cam 30. This is in conjunction with... Figure 6 In the same state as the central diagram, the axis center of the eccentric shaft portion 260 of the eccentric shaft 26 is horizontally positioned behind the axis center of the body shaft portion 261. At this time, the main feed table 22 and the differential feed table 23 remain approximately horizontal only near the top dead center, so the main feed gear 20 and the differential feed gear 21 remain approximately horizontal only near the top dead center.

[0105] In the first stage, it is used in the sewing of fabrics such as shirts or ribbed fabrics such as T-shirts. When the fabric stretches or shrinks due to sewing, the input device of the stepper motor 5 slightly rotates the active cam 30, causing a slight increase or decrease in the force of conveying the fabric. This allows for adjustment in a way that eliminates the stretching or shrinkage of the fabric to a certain extent. In conventional technology, the screw fixing of the eccentric shaft 26 is loosened, rotated by hand, and then the screw is tightened again for adjustment, which requires tools and time. In this embodiment, for example, by using the input device of a touch panel, tools are not required, and the time is reduced.

[0106] Figure 8 This is a left-side view showing the second stage of the feed tooth tilt adjustment member and the presser foot lifting member of the device for adjusting the presser foot lift and feed tooth tilt in the sewing machine of this utility model. In the second stage, it shows the cam follower 310 of the feed tooth tilt adjustment rod 31 contacting near the boundary of the transition region 302 within the feed tooth tilt adjustment region 300 of the driving cam 30. This is in contrast to... Figure 6 In the same state as shown in the figure above, the center of the eccentric shaft portion 260 of the eccentric shaft 26 is located behind and below the center of the shaft portion 261 of the body. At this time, the main feed table 22 and the differential feed table 23 are tilted upward in the forward direction. Therefore, the main feed gear 20 and the differential feed gear 21 are tilted upward in the forward direction when they move up and down and back and forth on the upper surface of the needle plate 11.

[0107] The second stage is used for sewing thicker parts of the fabric, such as steps or strips formed by overlapping. When the thicker part of the fabric is blocked at the front end of the presser foot 12 and cannot move forward, the operation is temporarily stopped, and the differential feed tooth 21 is tilted upward in the forward direction from the first stage to the second stage, thereby increasing the force of conveying the fabric.

[0108] Figure 9 This is a left-side view showing the third stage of the feed tooth tilt adjustment member and the presser foot lifting member of the device for adjusting the presser foot lift and feed tooth tilt in the sewing machine of this invention. In the third stage, it shows the cam follower 310 of the feed tooth tilt adjustment rod 31 contacting near the boundary of the presser foot lift area 301 within the feed tooth tilt adjustment area 300 of the driving cam 30. This is in conjunction with... Figure 6 In the same state as shown in the diagram below, the center of the eccentric shaft portion 260 of the eccentric shaft 26 is located behind and above the center of the shaft portion 261 of the machine body. At this time, the main feed table 22 and the differential feed table 23 are tilted downward in the forward direction. Therefore, the main feed gear 20 and the differential feed gear 21 are tilted downward in the forward direction when moving up and down and back and forth.

[0109] In the third stage, the main feed tooth 20 and the differential feed tooth 21 descend significantly as a whole. During up-and-down and back-and-forth movements, their upper ends do not protrude onto the upper surface of the needle plate 11; that is, it is used as a descending feed state. Furthermore, by slightly rotating the drive cam 30 from the third stage state, the contact point between the cam follower 310 and the drive cam 30 returns to the inner part of the feed tooth tilt adjustment area 300, thereby slightly mitigating the downward tilt and causing a portion of the rear end of the main feed tooth 20 to protrude onto the upper surface of the needle plate 11. In this state, through the up-and-down and back-and-forth movements of the main feed tooth 20 and the differential feed tooth 21, only a portion of the rear end of the main feed tooth 20 moves back and forth on the upper surface of the needle plate 11. This simply serves as an anti-unraveling device to reduce stitch spacing.

[0110] Figure 10 This is a left-side view showing the fourth stage of the feed tooth tilt adjustment member and the presser foot lifting member of the device for adjusting the presser foot lift and feed tooth tilt in the sewing machine of this utility model. In the fourth stage, moving forward from the third stage, it shows the case where the cam follower 310 of the feed tooth tilt adjustment rod 31 is engaged at the middle of the presser foot lifting area 301 of the drive cam 30. Within the presser foot lifting area 301, similar to the third stage, the axis center of the eccentric shaft portion 260 of the eccentric shaft 26 is located rearward and above the axis center of the machine body shaft portion 261, resulting in a downward feed state.

[0111] As the process transitions from the third to the fourth stage, the swing end of the active crank 40 descends, the presser foot lifting active linkage 41 descends, and the swing end of the presser foot lifting active lever 42 descends. Consequently, the engaging portion 420 of the presser foot lifting active lever 42 engages with the intermediate crank 43. If the swing end of the presser foot lifting active lever 42 descends further from this point, the engaging portion 420 of the presser foot lifting active lever 42 engages with the intermediate crank 43 and presses down on the intermediate crank 43, while simultaneously swinging downwards.

[0112] Figure 11 This is a left-side view showing the fifth stage of the feed tooth tilt adjustment member and the presser foot lifting member of the device for adjusting the presser foot lift and feed tooth tilt in the sewing machine of this invention. In the fifth stage, progressing from the fourth stage, it shows the cam follower 310 of the feed tooth tilt adjustment rod 31 contacting near the boundary of the presser foot lift area 301 within the area of ​​the presser foot lift area 301 of the driving cam 30. In this state, as in the third and fourth stages, the axis center of the eccentric shaft portion 260 of the eccentric shaft 26 is positioned above the axis center of the body shaft portion 261, resulting in a downward feed state.

[0113] As the process moves from the fourth stage to the fifth stage, the swing end of the drive crank 40 descends further, the engaging part 420 of the presser foot lifting drive lever 42 engages with the intermediate crank 43 and presses it down, while simultaneously swinging downwards. Furthermore, the presser foot lifting connecting rod 45, connected to the other swing end of the intermediate crank 43, moves downwards, and the presser foot lifting lever 46 swings downwards. The engaging part 460 of the presser foot lifting lever 46 is located in front of the presser foot height adjusting screw 48. By swinging the presser foot lifting lever 46 downwards, it engages with the presser foot height adjusting screw 48 and presses it backwards, causing the presser foot lifting shaft crank 47 to swing downwards, thus swinging the presser foot platform shaft 17. Furthermore, by swinging the presser foot platform shaft 17, the presser foot 12 swings upwards via the presser foot platform 13, thereby driving the presser foot to lift. Thus, in the fifth stage, the presser foot is lifted while in a descending feed state.

[0114] Figure 12 This is a left-side view of the presser foot height sensor component and the pneumatic presser foot pressing component of the device for adjusting the presser foot lifting and feed tooth tilt of the sewing machine used in this utility model. The following is based on... Figure 12 Another embodiment of this utility model will be described. In this embodiment, the device for adjusting the presser foot lifting and feed tooth tilt includes a presser foot height sensor component 6 for detecting the vertical position of the presser foot. The presser foot height sensor component 6 includes: a Hall sensor 60, which is disposed near the side of the presser foot platform 13 on the sewing machine body 10; and a permanent magnet 61, which is fixed to the middle part of the presser foot platform 13. Thus, when the permanent magnet 61 is moved vertically by the vertical movement of the presser foot 12 and the presser foot platform 13, the strength of the magnetic field changes, and the voltage output by the Hall sensor 60 changes. Therefore, the vertical position of the presser foot 12 can be detected based on the various voltage values ​​output by the Hall sensor 60 corresponding to various vertical positions of the presser foot 12.

[0115] When there are thicker sections of fabric, such as steps or bands caused by overlapping, during sewing, as the fabric is conveyed and the thicker sections reach the front of the presser foot 12, the raised portion at the front of the presser foot 12 is pressed up. If the force of conveying the fabric is insufficient, the fabric will become blocked at the front of the presser foot 12 and struggle to advance. In the prior art, in this situation, the operation is temporarily stopped, the eccentric shaft 26 is loosened and rotated, then fixed again, causing the differential feed tooth 21 to tilt upwards in the forward direction, thereby increasing the force of conveying the fabric at the front of the presser foot 12. In this embodiment, the presser foot height sensor 6 detects the vertical position of the presser foot 12. By cooperating with the control device of the stepper motor 5, the feed tooth tilt adjustment member 3 can be activated without stopping the operation, causing the differential feed tooth 21 to tilt upwards in the forward direction at the thicker sections of the fabric, thereby increasing the force of conveying the fabric without requiring time.

[0116] In this embodiment, the device for lifting the presser foot and adjusting the feed tooth tilt includes a pneumatic presser foot pressing component. The pneumatic presser foot pressing component 7 includes: a cylinder 70, which is arranged axially in the front-rear direction above and behind the presser foot 12; a bracket 71, which is mounted on the sewing machine body 10 and fixed to the cylinder 70; and a double-arm crank 72, which swings around a pivot pin (not shown) mounted on the sewing machine body 10, with one swing end connected to the front end of the cylinder 70's pivot shaft and the other swing end connected to the upper end of the presser foot lever 14, thereby transmitting force. The presser foot lever spring 15 is omitted in this embodiment.

[0117] Therefore, when the presser foot 12 rises and the presser foot lever 14 rises via the presser foot platform 13, the compression of the presser foot lever spring 15 increases, thus increasing the downward force on the presser foot 12. However, in this example, since the presser foot 12 is pressed using the cylinder 70 via the double-arm crank 72, the downward force on the presser foot 12 remains constant. Therefore, when the differential feed tooth 21 is tilted forward and upward in the aforementioned thicker fabric portion to increase the force of conveying the fabric, the downward force on the presser foot 12 does not increase, thus allowing for smoother fabric conveying.

[0118] According to the above-described device for adjusting the presser foot lift and feed tooth tilt of an overlock sewing machine, the overlock sewing machine includes: a needle that reciprocates up and down; upper and lower loopers that reciprocate left and right in conjunction with the needle; a needle plate disposed on the sewing machine body and supporting the fabric from below; a presser foot that supports the fabric from above; and main feed teeth and differential feed teeth that move up and down and back and forth. This overlock sewing machine also includes: a stepper motor; a feed tooth tilt adjustment member linked to the stepper motor; a presser foot lift member linked to the stepper motor; and a control device for the stepper motor. This eliminates the following problems: the device for adjusting the presser foot lift and feed tooth tilt requires separate drive equipment for presser foot lift and lower feed, increasing the cost and price of the sewing machine; and it is impossible to use these drive equipment to adjust the tilt of the differential feed teeth.

[0119] This invention is not limited to the embodiments described above. Anyone skilled in the art can make various modifications to the embodiments without departing from the spirit of this invention, and this invention also includes these modifications. Furthermore, this embodiment uses an overlock sewing machine, but is not limited to this. For example, it can also be implemented using other circular sewing machines such as single-needle double-thread lockstitch sewing machines and safety sewing machines that have a similar mechanism to an overlock sewing machine.

Claims

1. A device for adjusting the presser foot lifting and feed tooth tilting of an overlock sewing machine, the overlock sewing machine comprising: a needle that reciprocates up and down; an upper looper and a lower looper that move in conjunction with the needle and reciprocate left and right; a needle plate disposed on the sewing machine body and supporting the fabric from below; a presser foot that supports the fabric from above; and a main feed tooth and a differential feed tooth that move up and down and back and forth, characterized in that... The presser foot lifting and feed tooth tilting adjustment device of the overlock sewing machine includes: a stepper motor; a feed tooth tilting adjustment member linked to the stepper motor; a presser foot lifting member linked to the stepper motor; and a control device for the stepper motor.

2. The device for lifting the presser foot and adjusting the inclination of the feed teeth in an overlock sewing machine according to claim 1, characterized in that, The device for adjusting the pressure foot lifting and feed gear tilt includes: a drive crank that fixes the pressure foot lifting member to the motor shaft of the stepper motor; and a pressure foot lifting drive linkage, one end of which is connected to the drive crank. A presser foot lifting active lever is connected to the other end of the presser foot lifting active connecting rod; an intermediate crank, the swinging end of which is connected to the swing center of the presser foot lifting active lever, swings together with the intermediate crank when the engaging part of the presser foot lifting active lever is engaged with the intermediate crank and pressed; a shaft pin is inserted into a shaft hole provided at the swing center of the intermediate crank and is configured to allow the intermediate crank to swing; a presser foot lifting connecting rod, one end of which is connected to the other swinging end of the intermediate crank that is not connected to the presser foot lifting active lever; and a presser foot lifting lever. Its swing end is connected to the other end of the presser foot lifting linkage, and the shaft hole provided at the swing center can swing through the presser foot platform shaft; the presser foot lifting shaft crank is fixed to the presser foot platform shaft on the side of the presser foot lifting rod; and the presser foot height adjusting screw is inserted into the threaded hole provided in the presser foot lifting shaft crank and is fixed in such a way that the front end of the screw protrudes. When the engaging part of the presser foot lifting rod is engaged with the presser foot height adjusting screw and pressed, the presser foot lifting shaft crank swings together with the presser foot lifting rod.

3. The device for lifting the presser foot and adjusting the inclination of the feed teeth in an overlock sewing machine according to claim 2, characterized in that, The device for lifting the presser foot and adjusting the tilt of the feed gear includes a presser foot height sensor component for detecting the vertical position of the presser foot.

4. The device for lifting the presser foot and adjusting the inclination of the feed teeth in an overlock sewing machine according to any one of claims 1 to 3, characterized in that, The presser foot lifting and feed gear tilt adjustment device comprises: a drive cam that fixes the feed gear tilt adjustment member to the motor shaft of the stepper motor; a feed gear tilt adjustment rod that swings in conjunction with the drive cam; a feed gear tilt adjustment linkage, one end of which is connected to the feed gear tilt adjustment rod; and an eccentric shaft crank that is connected to the other end of the feed gear tilt adjustment linkage and is fixed at the center of the swing to the machine body shaft of the eccentric shaft provided on the sewing machine body.

5. The device for lifting the presser foot and adjusting the inclination of the feed teeth in an overlock sewing machine according to claim 4, characterized in that, The device for lifting the presser foot and adjusting the tilt of the feed tooth has a feed tooth tilt adjustment area, a presser foot lifting area, and a transition area on the cam profile of the active cam and the feed tooth tilt adjustment rod.

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