JP2543843Y2 - Threading device in automatic thread trimming sewing machine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an automatic sewing machine, and has a function of automatically cutting a thread after sewing by operating a thread cutting mechanism. The present invention relates to a thread pulling device in a sewing machine.

[0002]

2. Description of the Related Art Conventionally, an automatic thread trimming machine that operates a thread trimming mechanism by a drive signal input from a foot switch or the like to cut a thread after sewing has been used. In the device, as a mechanism to prevent the upper thread cut under the needle from being pulled out from the needle hole at the start of the next sewing, the upper thread is adjusted by an upper thread adjusting mechanism (thread tensioner) before the upper thread is cut by the thread cutter. A yarn loosening device that releases the yarn feeding resistance to the yarn,
There is a thread pulling device for providing in advance the amount of thread coming off as the needle bar descends, and is configured to be driven by independent solenoids.

That is, the thread loosening device and the thread pulling device are operated by separate and independent driving sources, and when the thread pulling device is attached to the arm portion of the sewing machine, a thread loosening solenoid and a thread pulling solenoid are used. However, the number of parts has increased, and securing installation space has been a problem.

[0004] In order to solve these problems, the applicant of the present application has previously described a drive source used also as a thread loosening device as shown in FIG. In addition, a compact stringing device was proposed.

In this thread pulling device, a solenoid 53 is fixedly mounted on a mounting plate 52 fixed to a part of the sewing machine, and a thread loosening operating portion 57 of an upper thread adjusting mechanism 58 provided on the mounting plate 52.
Oscillating plate 5 oscillating by driving the solenoid 53
5 through a drive connection. In a fulcrum position adjusting bracket 62 fixed to the mounting plate 52 via a fulcrum adjusting screw (not shown) so as to be capable of adjusting the mounting position in the rod direction, a thread hooking end 72 is located in the upper thread supply path of the sewing machine. Threading rod 6
The base 3 is mounted so as to be swingable in the front direction and to be adjustable in the mounting direction in the rod direction by the mounting position adjusting screw 70. In addition, the vicinity of the base of the threading rod 63 is pivotally connected to the drive shaft 54 of the solenoid 53 via a fastening nut 71, and the threading ends 72 of the threading rod 63 are located on both sides thereof. Pull out at a predetermined timing from between,
This is a configuration in which the upper thread a is given a slack.

[0006]

However, in the threading device having the above-described structure, the amount of threading is determined by the relative displacement between the threading guide rod 73 and the threading end 72 of the threading rod 63. Since there is a variation in the amount of threading that is approximately twice the amount of displacement, fine adjustment cannot be performed in the rod-direction mounting position adjustment of the threading rod 63 using the fulcrum adjusting screw and the mounting position adjusting screw 70, and a positional shift occurs during fastening. And it was very troublesome.

The present invention has been made in view of the above-mentioned problems, and it is possible to extremely easily and accurately adjust the amount of stringing, and also to reduce the installation space by using a driving source also as a yarn loosening device to reduce the installation space, thereby forming an arm portion. It is an object of the present invention to provide a thread pulling device in an automatic thread trimming sewing machine which is simple and compact.

[0008]

SUMMARY OF THE INVENTION A thread pulling device in an automatic thread trimming machine according to the present invention is an automatic thread trimming device which operates a thread trimming mechanism by a drive signal input from a foot switch or the like to cut a thread after sewing. A solenoid is fixedly mounted on a mounting plate fixed to a part of the thread trimming sewing machine, and the driving plate is connected to a thread loosening mechanism of a needle thread adjusting mechanism via a swinging continuous plate which is swung by driving the solenoid. The base of the thread pulling rod having the thread hooking end positioned in the upper thread supply path of the sewing machine is fixed to the rod mounting position adjusting mechanism fixed to the mounting plate by a hinge portion and a fulcrum adjusting screw so that the rod direction mounting position can be adjusted freely. And the base of the stringing rod is pivotally connected to the drive shaft of the solenoid, and the threaded ends of the stringing rod are arranged at predetermined timing from between the stringing guide rods located on both sides thereof. Pull forward and loosen the upper thread The thread pulling amount adjusting mechanism includes a sliding screw threadedly engaged with a screw shaft erected on an adjusting screw mounting base fixed to the mounting plate; and a screw shaft with respect to the adjusting screw mounting base. A fulcrum receiving bracket pivotally mounted so as to be freely displaceable in the direction is axially engaged, and a threading rod fixing bracket is pivotally mounted on the fulcrum bracket via a stepped screw so as to be rotatable in the horizontal direction. The gist of the present invention is to fix the base end of the rod to form a pivot point.

[0009]

According to the above construction, when the solenoid is driven, the upper thread adjusting mechanism releases the thread via the swinging continuous plate and enters the free-feeding state. At the same time, the thread pulling rod swings around the fulcrum,
Since the threading end moves forward from between the threading guide rods, the thread passing through the portion is drawn forward from between the quantity rods of the threading guide rod.

[0010] The amount of this pull-out is determined by the amount of movement of the yarn hooking end projecting forward from the yarn pulling guide rod.
Since the moving stroke is constant depending on the stroke of the solenoid, it can be adjusted by the relative position of the fulcrum, whereby the length of the remaining thread on the needle side can be adjusted. The relative position can be implemented by changing the fastening position of the fulcrum position adjusting screw by the screw action of the threading amount adjusting mechanism. The adjusting operation of the rotation fulcrum position requires fine adjustment by the screw action. Possible and accurate.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a threading device in an automatic thread trimming sewing machine according to the present invention will be described below with reference to FIGS.

FIGS. 1 and 2 show a front view and a rear view of the threading device 1, respectively, which are fixed to an arm of a sewing machine 40. A solenoid 3 is fixedly mounted on the back surface of a solenoid mounting portion 2a formed by bending the lower end of the mounting plate 2 forward, and its drive shaft 4 is positioned so as to be orthogonal to the mounting plate 2 and protrude and retract in the rear direction. It becomes. On the back surface of the mounting plate 2, a swinging connecting plate 5 has an upper end swingably attached to the upper end via small screws 6 and 6, and
The lower end of the oscillating continuous plate 5 is pivotally connected to the drive shaft 4 of the solenoid 3, and is freely swingable in the front-rear direction by the drive stroke S1 of the solenoid 3 with the play portion of the small screws 6, 6 as a fulcrum. The rocking plate is provided with a thread tightening operating portion 7, and two thread clamping plates are pivotally mounted on a front surface of the mounting plate 2 corresponding to the portion, on a support shaft erected on the mounting plate 2. The upper thread adjusting mechanism 8 disclosed in, for example, Japanese Utility Model Laid-Open Publication No. 50-71147, in which both clamping plates are pressed by a spring, is fixed. The thread loosening operating section 7 is in contact with the tip of a thread loosening pin 9 for disengaging the holding board of the upper thread adjusting mechanism 8 penetrating through the mounting plate 2, and is provided in the forward direction of the swinging continuous board 5. A thread-releasing mechanism is configured to release the two holding boards of the upper thread adjusting mechanism 8 against the spring by release through the thread-releasing pin 9 by swinging. Incidentally, reference numeral 11 denotes a known thread take-up belt.

An adjusting screw mounting base 14 of a threading amount adjusting mechanism 12 for pivotally connecting a base of a threading rod 13 to be described later is fixed to the adjusting mechanism mounting portion 2b of the mounting plate 2. The threading amount adjusting mechanism 12 engages a sliding screw boss 16 with a screw shaft 15 erected on an adjusting screw mounting base 14, and the sliding screw boss 16 is externally inserted around an outer periphery of a step portion of the sliding screw boss 16. The screw 17 is integrated by a set screw 18 and the circumferential groove 1 formed by the sliding screw boss 16 and the sliding screw 17 is formed.
9, a circular hole 21 of a fulcrum receiving member 20 is rotatably provided on a shaft. Reference numeral 22 denotes a lock nut screwed to the rear end of the screw shaft 15.

The fulcrum support member 20 engages a rotation stop pin 23 erected at the upper end with a sliding hole 24 formed in the adjusting screw mounting base 14 so as to be slidable in the axial direction of the screw shaft 15. A thread pulling rod fixing bracket 25 is pivotally mounted on a lower end hinge portion 20a bent in an L-shape via a stepped screw 26 so as to be rotatable in the horizontal direction.
3 are formed. The thread pulling rod fixing bracket 25 is always urged and resiliently biased in the direction of arrow E1 by a coil spring 27 elastically mounted between the thread pulling rod fixing bracket 25 and the hinge portion 20a.

The thread pulling rod 13 has two parallel rods 28 and 29 formed by bending a wire at the base thereof, and the parallel rod 28 at the end side is attached to the thread through a mounting position adjusting screw 30. The parallel rod portion 29 at the point of force B is connected to the drive shaft 4 of the solenoid 3 while being fastened to the pull rod fixing bracket 25.
Fastened to the end via a fastening nut 31, each arrow D
It has a function of adjusting the fastening position in two directions. Further, the leading end of the thread pulling rod 13 forms a thread hooking end 32 whose plane shape is curved in a forward concave shape, and the thread hooking end 32 is loosely fitted in a groove below a balance 41 formed in an arm portion of the sewing machine. In addition, it is supported so as to always be located behind a front-shaped U-shaped thread pulling guide rod 33 fixed to the arm portion, and forms a thread pulling action point C. The solenoid 3 is driven by suction (arrow D3). Then, the thread pulling rod 13 swings with the stepped screw 26 as the rotation fulcrum A, and the thread hooking end 32 is displaced forward against the elasticity of the coil spring 27.

In the drawing, reference numeral 37 denotes an upper thread adjusting mechanism 8 for the upper thread.
43 is a base tension device for constantly applying a very weak resistance, and 43 is a needle cap 4 to which a sewing needle 44 is attached.
The needle drop section 43 is provided below the needle drop section 5, and the needle drop section 43 incorporates an automatic thread trimming device 46 driven by an input signal from a foot switch or the like via a central control device (one-chip LSI). .

Further, the solenoid 3 sucks at the operation timing from the central control unit synchronized with the operation input of the automatic thread cutting device 46.

As shown in FIG. 8, when the solenoid 3 is driven, the swinging connecting plate 5 and the thread pulling rod 13 are sucked by the driving shaft 4.
Is moved by the drive stroke S1. This displacement pushes the thread loosening pin 9 of the upper thread adjusting mechanism 8 via the oscillating connecting plate 5, so that the two holding plates are in a disengaged free feeding state. At the same time, the thread pulling rod 13 swings with the stepped screw 26 as the rotation fulcrum A, and the thread hooking end 22 which is the action point C moves forward from between the two rods of the thread pulling guide rod 33, The thread a passing through the portion between the balance 41 and the sewing machine needle 44 is drawn forward from between the two thread guide rods 33.

The withdrawal amount is the amount of movement (Sa, S, Sb) of the yarn hooking end 22 projecting forward from the yarn pulling guide rod 33.
Since the movement stroke S1 of the force point position B is constant by the stroke of the solenoid 3, the position of the stepped screw 26 serving as the fulcrum A can be adjusted by relative movement (arrow D1). The position of the stepped screw 26 can be achieved by rotating the sliding screw 17 of the threading amount adjusting mechanism 12. When the sliding screw 17 is rotated, the sliding screw boss 16 integrated with the sliding screw 17 is screwed with the screw shaft 15, and the screwing action causes the fulcrum support 20 to move in the direction of arrow D1. Displace. After the displacement adjustment, the sliding screw boss 16 can be fixed at the adjustment position by fastening the lock nut 22.

Here, by adjusting the position of the fulcrum A, the displacement of the position relative to the arm of the threading end 32, which is the point of action C of the thread pulling rod 13, can be corrected by the fastening nut fastened to the drive shaft 4 of the solenoid 3. With the fixing of the attachment position adjusting screw 30 to which the parallel rod portion 28 is fastened, with the attachment position adjusting screw 30 being loosened, the above-mentioned amount of adjustment is adjusted, and after the adjusting operation, the attachment position adjusting screw is tightened to complete the operation. I do.

[0021]

As described above, the threading device in the automatic thread trimmer according to the present invention adjusts the amount of threading by changing the rotation fulcrum position of the threading rod that determines the amount of threading. By making the structure to be displaced by a screw action, fine adjustment can be easily and accurately performed. In addition, in the configuration of the present invention, since the yarn loosening device and the yarn drawing device are driven by one solenoid, the number of parts can be reduced, and the installation space can be reduced and the size can be reduced. It has excellent features such as the following, and the practical effect after implementation of the present invention is extremely large.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of a sewing machine showing an embodiment provided with a thread pulling device according to the present invention.

FIG. 2 is a rear view of the yarn pulling device.

FIG. 3 is a partially cutaway front view of the threading amount adjusting mechanism.

FIG. 4 is a rear view of the same.

FIG. 5 is a right side view of the same.

FIG. 6 is a plan view of the same.

FIG. 7 is a perspective view of the main part.

FIG. 8 is an explanatory view showing a threading amount adjusting action of the present apparatus.

FIG. 9 is a rear view showing a conventional stringing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Threading device 2 Mounting plate 5 Oscillating continuous plate 8 Upper thread adjusting mechanism 13 Threading rod 12 Threading amount adjusting mechanism 14 Adjusting screw mounting base 15 Screw shaft 16 Sliding screw boss 17 Sliding screw 20 Supporting point support 23 Around Lock pin 25 Thread puller fixing bracket 26 Step screw 27 Coil spring 28,29 Parallel rod 30 Mounting position adjusting screw 31 Fastening nut 32 Thread end 33 Thread guide bar 44 Sewing needle 46 Automatic thread cutter 41 Balance a Thread

Claims (1)

(57) [Scope of request for utility model registration] An automatic thread trimming machine that operates a thread trimming mechanism to cut a thread after sewing in response to a drive signal input from a foot switch or the like, wherein a solenoid is fixed to a mounting plate fixed to a part of the sewing machine. A thread having a thread hooking end positioned in the upper thread supply path of the sewing machine, and being drivingly connected to the mounting plate via a swinging continuous plate which swings by driving the solenoid, and a thread loosening mechanism of the upper thread adjusting mechanism. The base of the pull rod is fixedly mounted on the mounting plate in such a manner that the mounting position in the rod direction can be freely adjusted via a hinge portion of a thread pulling amount adjusting mechanism fixed to the mounting plate and a fulcrum adjusting screw. It is configured to be pivotally connected to the drive shaft, and the thread hooking end of the thread pulling rod is pulled forward at a predetermined timing from between the thread pulling guide rods located on both sides thereof, thereby giving a slack to the upper thread, The threading amount adjusting mechanism is A sliding screw threadedly engaged with a screw shaft erected on an adjusting screw mounting base fixed to the mounting plate, and a fulcrum receiving bracket pivotally displaceable in the screw axis direction with respect to the adjusting screw mounting base in the axial direction. At the same time, a thread pulling rod fixing bracket is axially mounted on the fulcrum fitting via a stepped screw so as to be rotatable in the horizontal direction, and the base end of the thread pulling rod is fixed to form a pivot point. A thread pulling device in an automatic thread trimming sewing machine, wherein