JP4614114B2 - Sewing machine with thread trimmer - Google Patents

Description

  The present invention relates to a sewing machine with a thread trimming device applied to sewing of a cylindrical portion such as a neck of a T-shirt, sewing of a cuff, or covering. Specifically, a cloth bed having a cylindrical bed suitable for sewing a cylindrical portion, and feeding the needle drop hole and the cloth in the cylinder axis direction perpendicular to the cylinder axis direction at the free end of the cylinder bed. A needle plate having a tooth groove is fixed, and a looper is provided at the lower portion of the needle plate, and a needle thread and a looper thread located between the needle plate and the looper after sewing are provided on the side of the needle plate. The present invention relates to a multi-needle cylinder type sewing machine provided with a thread trimming device that draws the blades sideways and cuts them.

  This type of thread trimming device in a multi-needle cylinder type sewing machine has a tip that is bent like a hook and has a thread hook on the inner periphery of the bent tip, and the thread hook has a needle drop hole in the needle plate. A movable knife that is reciprocally driven and swung in a horizontal plane so as to traverse, and a needle thread and a looper thread that are hooked on the tip thread hook and transferred to the side of the needle drop hole when the movable knife is swung backward. A fixed knife that cuts by a shearing action with the movable knife, a movable knife pressing plate that comes into contact with the movable knife and elastically holds and guides the swing of the movable knife between the fixed knife and the cut yarn An end portion is provided with a thread pinching plate that can be elastically sandwiched between the distal end portion of the movable knife.

  By the way, in the sewing machine with a thread trimming device composed of the above components, as a movable knife driving mechanism for reciprocatingly swinging the movable knife, conventionally, the outer side surface of the sewing machine body integrally connected to the proximal end side of the cylindrical bed In addition, for example, a bidirectional electromagnet (solenoid) or a drive unit such as an air cylinder is mounted, while a movable member that linearly reciprocates along the cylinder axis direction (cloth feed direction) is provided in the cylindrical bed, The base end portion of the movable member and the movable portion of the driver are linked and linked through a link provided so as to protrude to one side of the cylindrical bed portion, and the distal end portion of the movable member and the movable knife are connected to each other. What is linked and linked is known (see, for example, Patent Document 1).

  Utility Model Registration No. 3101486

  In the conventional sewing machine with a thread trimming device provided with the movable knife driving mechanism configured as described above, a part of the driver and a link that operates in conjunction with the driver is exposed to the outside of the side of the sewing machine body. Alternatively, even if the exposed portion is covered, the cover protrudes to the outside of the side of the sewing machine body. For this reason, when inserting a cylindrical part, which is the product to be sewn, from the free end of the cylindrical bed and performing a predetermined sewing operation, the exposed part including the part of the operating link, the protruding part, etc. The sewing fabric becomes difficult to handle due to contact or contact, and as a result, the efficiency of sewing workability may not increase. Moreover, since there are many components for the interlocking | linkage cooperation with a movable knife and a driver, when attaching a thread trimming device to a sewing machine, there existed a problem that a great effort was required for those assembly | attachment.

  The present invention has been made in view of the above-described circumstances, and can reduce the number of components, reduce costs, facilitate assembling, rationalize, and facilitate the handling of the fabric during sewing work. An object of the present invention is to provide a sewing machine with a thread trimming device capable of improving the performance.

In order to achieve the above object, a sewing machine with a thread trimmer according to the present invention is arranged at a free end of a cylindrical bed at a needle drop hole and before and after the needle drop hole so as to be orthogonal to the cylinder axis direction. A needle plate having a groove for a cloth feed tooth that feeds the cloth in the cylinder axis direction is fixed, and a looper that reciprocally swings in a direction intersecting the cloth feed direction is provided in a cylindrical bed below the needle plate. The tip end side is curved like a hook and has a thread hook on the inner periphery of the bent tip, and the tip thread hook is centered on an axis provided on the back side of the needle plate. A movable knife that is reciprocally driven and swung in a horizontal plane between the looper reciprocating rocking movement path and the needle plate so as to cross the needle drop hole, and the movable knife is centered on an axis on the back side of the needle plate And a movable knife drive mechanism that swings back and forth and the movable knife drive mechanism A fixed knife that cuts the needle thread and looper thread that are hooked on the tip thread hook when the knife moves backward and is transferred to the side of the needle drop hole by a shearing action between the knife and the movable knife; A movable knife pushing plate that contacts the knife and elastically holds and guides the swinging movement of the movable knife between the fixed knife and a thread that can elastically hold the cut thread end between the tip of the movable knife In the sewing machine with a thread trimmer provided with a pinch plate, the movable knife driving mechanism is pivotally connected at one end to an intermediate portion between the reciprocating center axis of the movable knife and the tip thread hook. A drive connecting link having an end portion extending in the cloth feeding direction in the cylindrical bed, and a movable rod portion pivotally connected to the other end of the drive connecting link and reciprocating linearly in the cloth feeding direction. And a fluid pressure cylinder fixedly installed in the cylindrical bed. Are, the fluid pressure cylinder constituting the moving knife drive mechanism, the inner cover tubular being interposed standing fixed between the upper cover portion for covering the upper portion of the lower bed portion and a lower portion bed of the cylindrical bed is tipped destination set fixed mounted on the inside cover prior to incorporation into the bed, and, in the tip portion of the drive connection link on said cover so as to pivotally connected to the intermediate portion of the movable knife The cover is sandwiched and fixed between the lower bed portion and the upper cover portion of the cylindrical bed, so that the movable knife driving mechanism is not exposed or protrudes laterally from the cylindrical bed. It is characterized by being assembled et al.

  According to the present invention having the above-described characteristic configuration, all of the drive connection link, the movable rod portion, and the fluid pressure cylinder that constitute the movable knife drive mechanism are accommodated in the cylindrical bed. As in the conventional example shown, there is no exposed portion or protrusion to the outside of the side of the sewing machine main body near the base end of the cylindrical bed, and a sufficiently wide space is provided on the base end side of the cylindrical bed. Can be secured. Therefore, when inserting the cylindrical part of the sewing material having a large body from the free end of the cylindrical bed and performing a predetermined sewing operation, the large body is freely turned or moved without being obstructed. For example, it is possible to facilitate the handling of the sewing fabric and improve the sewing workability. In addition, as described above, the number of components of the movable knife driving mechanism is very small, and not only can the configuration be simplified to save costs, but also the time and effort required for retrofitting the thread trimmer to the sewing machine. Can be reduced.

In particular, the fluid pressure cylinder constituting the movable knife driving mechanism is fixedly installed on an inner cover sandwiched and fixed between a lower bed portion of a cylindrical bed and an upper cover portion covering the upper portion of the lower bed portion. tipping destination was set Te, and said inner cover so as pivotally linking the intermediate portion of the movable knife tip portion of Oite the drive connection link on the inner cover, the upper and lower bed of the cylindrical bedspreads Since the structure that is sandwiched and fixed between the two parts is adopted, the fluid pressure cylinder and the drive connection link are fixed and incorporated in a narrow space such as the inside of the cylindrical bed, or linked and connected. The assembly work is not required, and these components are placed on the inner cover before being installed in the cylindrical bed under a wide space, and the inner cover is sandwiched between the lower bed part and the upper cover part. By fixing, it is possible to assemble a predetermined exactly at a predetermined position in the fluid pressure cylinder and the drive coupling link cylindrical bed, further facilitating the assembling work of the movable knife drive mechanism, making it possible to streamline There is an effect that can be done.

In the sewing machine with a thread trimming device according to the present invention, the thread hooking portion on the inner periphery of the curved tip of the movable knife may be formed so that both the needle thread and the looper thread are hooked on one thread hooking portion. In particular, as described in claim 2 , the thread hooking portion of the inner periphery of the curved tip of the movable knife is divided into a needle thread hooking portion for hooking the needle yarn and a looper yarn hooking portion for hooking the looper yarn. It is preferable to form. In this case, the needle thread and looper thread are captured separately and cut separately with a time lag, resulting in wear on the blade edge due to excessive cutting load acting on the movable knife and fixed knife at once (blade spillage). ) And deformation as much as possible, and the yarn cutting performance can be satisfactorily maintained over a long period of time without frequent knife replacement.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic perspective view of an entire three needle cylinder type sewing machine with a thread trimming device according to the present invention, FIG. 2 is an exploded perspective view of components of the thread trimming device, and FIG. 3 is a cross-sectional view of a part of the sewing machine. FIG. 4A is an enlarged vertical sectional view taken along the line XX of FIG. 3, and FIG. 4B is an enlarged view of portion B of FIG. 4A. It is. This three-needle cylinder type sewing machine M has a sewing machine spindle, a needle drive mechanism and a presser drive mechanism (these are well-known and detailed structure) from the lower part of the machine bed part (sewing machine body) 2 to the front. The cylindrical bed 1 is extended along with the sewing machine arm portion 3 containing the same.

  As shown in FIG. 2, the cylindrical bed 1 is divided into a lower bed portion 1A that opens upward and an upper cover portion 1B that covers the upper opening of the lower bed portion 1A. A plate-like inner cover 30 described later is provided between the portion 1A and the upper cover portion 1B so as to be sandwiched and fixed. A needle plate 5 is fixed on the free end of the lower bed portion 1A of the cylindrical bed 1 via a needle plate spacer 31 and a screw 4, and the lower portion of the needle plate 5 is shown in FIG. As described above, the looper 6 and the looper driving mechanism that reciprocately swing in the bc direction intersecting (orthogonal) with the cloth feeding direction (sewing progress direction) a (this is well known, and the detailed structure and description thereof are omitted. And a bed cover 7 surrounding the looper 6 and the looper drive mechanism is provided at the free end of the cylindrical bed 1 so as to be detachable from the front end side.

  A needle bar 8 that is reciprocated up and down and a presser bar 9 that can be moved up and down are supported in a protruding state downward at the tip of the sewing machine arm 3. The three needles 11 are attached in parallel in a direction orthogonal to the cloth feeding direction a through the stopper 10 and the presser foot presses the sewing product against the needle plate 5 at the lower end portion of the presser bar 9. 12 is attached. The needle plate 5 has left and right sides 5a, 5a formed in parallel with the cloth feeding direction a. The needle plate 5 has three needle plates 5 orthogonal to the cylindrical axis direction of the cylindrical bed portion 2. Needle drop holes 13 are formed, and grooves 14 for cloth feed teeth (not shown because they are well-known) for feeding the cloth in the cylinder axis direction are formed on the front and rear sides and the left and right sides of the needle drop holes 13. A thread trimming device 18 having a movable knife 15, a stationary knife 16, a movable knife pusher plate 17, a thread pinching plate 27, etc., which will be described later as main components, is mounted on the back surface of the needle plate 5 that is formed.

  3 and 5 to 7 show a specific structure of the thread trimming device 18, and the movable knife 15 is bent in a hook shape on the tip side and hooks a single looper thread LT on the inner periphery of the curved tip. A looper yarn hooking portion 15a and a hook-like needle yarn hooking portion 15b for hooking three needle threads NT are separately formed, and a base end portion 15c of the movable knife 15 is formed on the needle plate 5. The looper 6 is reciprocally swung so that the two hook-shaped thread hooks 15a and 15b cross the three needle drop holes 13 with the screw shaft 19 as the center. When reciprocatingly swinging in the direction of the arrow de in the horizontal plane between the dynamic motion path and the needle plate 5, when the back plate is swung back to the retracted position shown by the solid line in FIGS. An outer peripheral edge 15d that does not protrude outward from one side 5a parallel to the cloth feed direction a of 5; When it is swung forward to the advance position shown by the phantom line in FIGS. 5 to 7, it is configured in a substantially sling shape having an inner peripheral edge 15 e located outside the cloth feed dog groove 14 of the needle plate 5. Yes.

  Further, the fixed knife 16 in the thread trimming device 18 is moved backward when the movable knife 15 swings backward from the advanced position indicated by the phantom line in FIGS. 5 to 7 to the retracted position indicated by the solid line in FIG. When swinging in the direction d from the arrow e, one looper thread LT and three threads hooked on the hook-like thread hooks 15a and 15b at the tip and transferred to the side of the needle drop hole 13 The needle thread NT is cut by a shearing action between the needle thread NT and the movable knife 15 pressed against the fixed knife 16 via the movable knife pusher plate 17. The movable knife 15 is elastically pressed and brought into contact with the fixed knife 16 so as to be elastically held between the fixed knife 16 and the thread end after cutting between the tip of the movable knife 15. It is an elastic sandwich.

  The fixed knife 16 having the above-described function has a blade edge 16a whose elastic contact point with the movable knife 15 is near the tip portion near the thread hooks 15a and 15b according to the reciprocating drive swing of the movable knife 15. The cloth so that the swing of the movable knife 15 is sandwiched and guided between the fixed knife 16 and the movable knife pushing plate 17 over the entire reciprocating drive swing range while changing between the part near the base end 15c. The rear side of the feed direction a is formed in an oblique straight line along an inclined direction gradually separating from the groove 14 for the cloth feed teeth, and the oblique straight edge 16a is directed to the front side in the cloth feed direction a. A mounting plate portion 16b parallel to the cloth feeding direction a is integrally formed, and the fixing knife 16 is fixed to the back surface of the temporary needle 5 via the screw member 28 in the mounting plate portion 16b.

  Further, the thread pinching plate 27 has a blade edge of the fixed knife 16 so as to pinch and guide the swing of the movable knife 15 between the movable knife 15 and the fixed knife 16 over the entire reciprocating drive swing range of the movable knife 15. A thread end pinching portion 27a that is long in a slanting straight line along the inclined direction is provided at a position slightly retreated from 16a, and the cloth extends from the slanting straight thread end pinching portion 27a toward the front side in the cloth feeding direction a. A mounting plate portion 27b parallel to the feed direction a is integrally formed, and the mounting plate portion 27b is fixed to the back surface of the fixed knife 16 via a screw member 32.

On the other hand, a cylinder mounting block 34 is fixed to the upper surface of the inner cover 30 corresponding to a position near the base end of the cylindrical bed 1 by welding or the like, and an air cylinder (a fluid pressure cylinder) is mounted on the mounting block 34. (Example) 20 is configured to be fixedly installed via a screw 33 screwed from the lower surface side of the inner cover 30. At the tip of the movable rod portion 21 of the air cylinder 20, there is a drive connection link 26 disposed on the inner cover 30 and extending in the cloth feeding direction (sewing progress direction) a in the cylindrical bed 1. The end portion is pivotally connected via a stopper collar 22, a nut 23, a mounting block 24, and a support shaft 25, and the distal end portion of the drive connection link 26 protrudes near the proximal end portion 15c of the movable knife 15. The pin 29 is fitted and connected so as to be relatively rotatable.

  The above-described air cylinder 20 with the movable rod portion 21 and the drive connection link 26 constitute a movable knife driving mechanism. This movable knife driving mechanism is mounted on the inner cover 30 before the inner cover 30 is assembled into the cylindrical bed 1. The inner cover 30 is sandwiched and fixed between the lower bed portion 1A and the upper cover portion 1B of the cylindrical bed 1 without being exposed or protruding sideways from the cylindrical bed 1. It is assembled inside the cylindrical bed 1.

  Next, the sewing and thread trimming operation by the three needle cylinder type sewing machine M provided with the thread trimming device 18 configured as described above will be described.

  For example, a cover ring or the like is sewn while the cylindrical portion of the sewing product inserted into the cylindrical bed portion 1 from the free end side is fed in a predetermined cloth feeding direction a via the cloth feeding teeth. When the predetermined sewing is completed, the movable knife 15 of the thread trimmer 18 is guided between the fixed knife 16 and the movable knife pusher plate 17 along a certain horizontal plane with no wobbling or the like. The hook-like thread hooks 15a and 15b at the tips of the needles 5 cross the three needle drop holes 13 in the needle plate 5 and drive forward to the advance position indicated by the phantom lines in FIGS. Then, the backward drive is swung from the advanced position to the retracted position shown by the solid line in FIGS. During the backward drive swing, the three needle threads NT passing through the needle drop hole 13 in the vertical direction are hooked on the thread hooking portion 15 b and one looper thread LT locked on the looper 6. Is hooked by the thread hook 15a, transferred to one side of the needle drop hole 13 and the feed dog groove 14, and is cut by the shearing action between the movable knife 15 and the fixed knife 16, and the cutting is performed. The thread end portion thus elastically sandwiched between the tip of the movable knife 15 and the thread end sandwiching portion 27a of the thread sandwiching plate 27.

  A movable knife in a sewing machine M in which a predetermined sewing operation is performed on a tubular portion such as a T-shirt neck, cuff stitching or covering by repeatedly performing the above-described thread cutting action and the thread end clamping action after cutting. A drive connecting link 26 constituting the driving mechanism, an air cylinder 20 and a stopper collar 22, a nut 23, a mounting block 24, and a support shaft 25, which interlock and link the movable rod portion 21 of the air cylinder 20 and the driving connecting link 26. All of the linked components such as the like are accommodated in the cylindrical bed 1 and the side of the sewing machine bed portion 2 near the base end portion of the cylindrical bed 1 as in the conventional example shown in Patent Document 1 Since there is no exposed portion or protruding cover portion to the outside, a sufficiently wide space is secured on the side of the base end portion of the cylindrical bed 1. Accordingly, when a predetermined sewing operation is performed by inserting a cylindrical portion of a sewing fabric having a large body from the free end of the cylindrical bed 1, the sewing fabricator freely swings and moves the large body. Can be easily handled, the sewing workability can be improved, and the occurrence of sewing errors can be reduced as much as possible.

Furthermore, as described above, since the number of components of the movable knife driving mechanism is very small, not only can the configuration of the movable knife driving mechanism be simplified to save costs, but also the thread trimming device Are attached to the sewing machine M, the components such as the air cylinder 20, the drive connecting link 26, and the linked components between the two are attached to the inner cover 30 before being assembled in the cylindrical bed 1. The inner cover 30 is attached to the lower bed of the cylindrical bed 1 so as to be fitted with the pin 29 that is assembled with the tip first and the distal end portion of the drive connecting link protrudes near the base end portion 15c of the movable knife 15. By sandwiching and fixing between the part 1A and the upper cover part 1B, it is possible to assemble the air cylinder 20 and the drive connection link 26 at predetermined positions in the cylindrical bed 1 as predetermined, and move. It is possible to perform the assembling operation of the scan drive mechanism easily and rationally.

  A hook-like looper yarn hooking portion 15a for hooking one looper yarn LT and a hook-like needle yarn hooking portion 15b for hooking three needle threads NT on the inner circumference of the curved tip of the movable knife 15; Are formed separately from each other, the needle thread NT and the looper thread LT are separately captured and cut individually with a time difference, so that an excessive cutting load is applied to the movable knife 15 and the fixed knife 16. It does not act at once, and it is possible to suppress blade edge wear (blade spillage) and deformation as much as possible due to excessive cutting load acting at once, so that frequent knife replacement is not required The yarn cutting performance can be maintained well over a long period of time.

  In the above embodiment, the three-needle cylinder type sewing machine M has been described in detail, but the two-needle cylinder type, the four-needle cylinder type, and the single-needle cylinder type sewing machine. You may apply to.

  In the above embodiment, the looper thread hooking portion 15a and the needle thread hooking portion 15b are separately formed on the inner periphery of the curved tip of the movable knife 15, but one hook-like thread is described. You may comprise so that a needle thread | yarn and a looper thread | hook may be hooked on a hanging part.

1 is a schematic perspective view of an entire three needle cylinder type sewing machine with a thread trimming device according to the present invention. It is a disassembled perspective view of the component of the thread trimming device in a sewing machine same as the above. It is a top view centering on the thread trimming device vicinity which is a principal part crossing a part of sewing machine same as the above. (A) is an enlarged longitudinal sectional view taken along line XX of (3), and (B) is an enlarged view of a portion B. It is an enlarged plan view of the principal part containing the same thread trimming apparatus. It is an expanded bottom view of the principal part containing a thread trimming apparatus same as the above. It is an enlarged plan view of only the same thread trimming apparatus.

DESCRIPTION OF SYMBOLS 1 Tubular bed 1A Lower bed part 1B Upper cover part 5 Needle plate 6 Looper 13 Needle drop hole 14 Groove for cloth feed dog 15 Movable knife 15a, 15b Hook-shaped thread hook part 16 Fixed knife 17 Movable knife pusher 18 System cut Device 19 Screw shaft 20 Air cylinder (fluid pressure cylinder)
21 Movable rod portion 26 Drive connection link 27 Thread pinching plate 30 Inner cover a Cloth feed direction (sewing advance direction)
M Three needle cylinder type sewing machine LT Looper thread NT needle thread

Claims (2)

At the free end of the cylindrical bed, there is a needle plate that has a needle drop hole orthogonal to the cylinder axis direction and a groove for a cloth feed tooth that is arranged before and after the needle drop hole and feeds the cloth in the cylinder axis direction. A looper that is fixed and reciprocally swings in a direction intersecting the cloth feeding direction is provided in the cylindrical bed below the needle plate, and the tip side is curved like a bowl to the inner circumference of the curved tip. A reciprocating rocking motion path of the looper and the needle plate so that the tip yarn hooking portion traverses the needle drop hole about a shaft provided on the back surface side of the needle plate. A movable scalpel capable of reciprocatingly swinging in a horizontal plane between them, a movable scalpel driving mechanism for reciprocatingly swinging the movable scalpel about the axis on the back side of the needle plate, and a movable scalpel by the movable scalpel driving mechanism. Side of the needle drop hole that is hooked by the thread hook at the tip of the backward drive swing A fixed knife that cuts the transferred needle thread and looper thread by a shearing action between the movable knife and a movable knife that contacts the movable knife and elastically holds and guides the swing of the movable knife between the fixed knife and the movable knife. In a sewing machine with a thread trimming device provided with a knife pusher plate and a thread pinching plate capable of elastically holding the cut thread end between the tip of the movable knife,
The movable knife driving mechanism has one end pivotally connected to an intermediate portion between the reciprocating center axis of the movable knife and the front thread hooking portion, and the other end directed toward the cloth feeding direction side in the cylindrical bed. A fluid pressure fixedly installed in the cylindrical bed, having an extended drive connection link and a movable rod portion pivotally connected to the other end of the drive connection link and linearly reciprocating in the cloth feed direction. It consists of a cylinder and
The fluid pressure cylinder constituting the movable knife driving mechanism incorporates an inner cover sandwiched between a lower bed portion of the cylindrical bed and an upper cover portion covering the upper portion of the lower bed portion into the cylindrical bed. and fixedly installed on the inside cover is tipped destination set before, and, said inner cover so as to pivotally connect the front end portion of the drive connection link on the inside cover to the intermediate portion of the movable knife, cylinder by clamping standing fixed between the lower bed portion and the upper cover portion of the form bed, without exposing or projecting the moving knife drive mechanism from the tubular bed sideways, Re et assembled inside the cylindrical bed A sewing machine with a thread trimming device.   2. The yarn according to claim 1, wherein the thread hooking portion on the inner periphery of the curved tip of the movable knife is divided into a needle thread hooking portion for hooking a needle yarn and a looper yarn hooking portion for hooking a looper yarn. Sewing machine with cutting device.

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