JP3523686B2 - Threading device in zigzag sewing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a threading device for a zigzag sewing machine. 2. Description of the Related Art A conventional threading device in a zigzag sewing machine is fixed to a sewing machine frame and is not linked to the vertical movement of a needle bar. The needle bar must be stopped in accordance with the position, and it is troublesome to stop the needle bar at a predetermined position in advance as a preparation step for performing a smooth threading operation, which is a troublesome device especially for a beginner. There were drawbacks such as the generation of noise when linked with the vertical movement of the rod. SUMMARY OF THE INVENTION [0003] The present invention has a fixed position of a needle bar of a threading device in a zigzag sewing machine relative to the position of a needle, thereby facilitating threading and reducing noise generated by the threading device. It is to try to make it. SUMMARY OF THE INVENTION The present invention relates to a needle bar support shaft supported by a sewing machine frame, and supported by the needle bar support shaft to be able to swing while being restricted from moving in a vertical direction. Needle bar support, a needle bar supported up and down by a pair of upper and lower arms extending from the needle bar support, and a threading shaft provided with an operation unit and a threading hook can be moved up and down. And a pair of upper and lower arms provided at one end of the needle bar support for supporting the needle bar with the respective arm portions of the needle bar support, and one end fixed to the threading frame. With the end fitted to the lower arm of the needle bar support,
Spring means interposed between the lower surface of the arm portion and the arm portion of the threading frame, wherein a hole provided in the upper arm of the threading frame is provided in the upper arm of the needle bar support. A zigzag sewing machine, which is slidably fitted to a portion of the needle bar, and wherein the spring means absorbs an impact in a thrust direction of the needle bar between the threading frame body and the needle bar support. The problem was solved by adopting the threading device in the above. According to the present invention, a threading device in a zigzag sewing machine is linked with a swinging motion and a vertical motion of a needle bar to fix a relative position of the threading device with respect to the needle bar, thereby preparing a threading operation. A spring member that acts in the thrust direction between the threading frame of the threading device and the arm of the needle bar support that supports the threading frame. With this arrangement, noise generated by the needle bar movement mechanism during the operation of the sewing machine is reduced. An embodiment of the present invention will be described below with reference to the drawings. A cam plate 3 is fixed to a part of the arm machine frame 1 of the sewing machine via an attachment plate 2 (see FIGS. 1 and 3), and further, a needle bar support is fixed to a part of the arm machine frame 1 via a fixing plate 4. Axis 5
Are rotatably supported (see FIG. 2). The cam plate 3 is integrally fixed to the mounting plate 2 by tightening screws 6, and the cam plate 3 is formed with an arc groove 37 at an appropriate position. Further, the fixing plate 4 is fixed to the arm machine frame 1 by a tightening screw 7, and the needle bar support shaft 5 is fitted in the groove 8 formed at the upper end to prevent the needle bar support shaft 5 from moving in the axial direction. ing. Needle bar support 9 is attached to needle bar support shaft 5.
The two arms 10, 10 having different heights are fitted, and the screw 1
It is fixed at 1. The needle bar support 9 is further provided with two arms 12 and 12 having different heights up and down, and the two arms are provided with a through hole having a common axis and a needle bar in the hole. 13 is fitted slidably in the axial direction. The needle bar support 9 has a radius R1 which intersects with a point of a needle of a thread catcher (not shown) that horizontally rotates the needle bar 13 about the needle bar support shaft 5 in the bed machine frame below. It makes a circular motion (see FIG. 3). The needle bar 13 is fixed to a needle bar dovetail 14, which fits on a needle bar crank 15 which is linked to the rotation of a drive shaft (not shown) rotatably supported by the arm machine frame 1. The needle bar 13 has a needle stopper 16 attached to the lower end thereof, and the sewing needle 17 is exchangeably fixed by the needle stopper. The threading frame 18 has two arms 19, 19 protruding from two upper and lower portions formed on the two arms 12, 12 of the needle bar support 9, which supports the needle bar 13 at the center. The upper and lower arms 19 of the threading frame 18 are formed of a plastic material. A threading shaft 23 is slidably fitted in the holes 22, 22 of the arms 21, 21 of the threading frame 18 penetrated at a specific distance Q from the axis of the needle bar 13. The vertical wall portion 24 is provided with a long cam groove 25 along the axis of the threading shaft 23.
A pin shaft 26 implanted in a direction perpendicular to the axis of the threading shaft 23 is slidably engaged with the cam groove. A compression coil spring 27 is fitted on the threading shaft 23 between the pin shaft 26 implanted in the perpendicular direction and the support arm 21 below the threading frame 18, and an operating portion 28 is provided at the lower end.
And a hook support arm 29 protruding in the axial direction of the needle bar 13 is provided, and a needle med 30 provided at the lower end of the sewing machine needle 17 is provided at the tip of the hook support arm.
Is provided with a threading hook 31 that can be inserted into the hook. A positioning member 32 of the threading shaft 5 is fixed to the needle bar 13, and an upper end surface 33 of the positioning member is extended so that the descending pin shaft 26 abuts thereon. When the operating portion 28 is operated and the threading shaft 23 is slid downward against the action of the spring 27 while stopped near the top dead center, the lower end of the threading shaft 23 The hook 31 provided in the section 3
It is provided at a position where it can be stopped at the height of the zero position. The upper arm 19 of the threading frame 18 is formed with a hole 34 into which the step 20 of the arm 12 of the needle bar support 9 is fitted. Narrow grooves 35, 35 larger than the diameter are formed, and the lower arm 19 of the threading frame 18 has a step 2 of the lower arm 12 of the needle bar support 9.
However, a leaf spring 36 is interposed between the upper surface of the lower arm 19 of the threading frame 18 and the lower surface of the step 20 of the needle bar support 9 (see FIG. 1). ). The upper end of the threading shaft 23 is engaged with an arc groove 37 formed in the cam plate 3 so as to be rotatable along an arc and to be slidable in a penetrating direction. The arc center of the arc groove 37 formed in the cam plate 3 is located at a position P at a fixed distance S from the center of the needle bar support shaft 5, and the fixed distance S is the center of the needle bar 13. The length of the arc radius R2 of the arc groove 34 coincides with the radius R1 of the needle bar 13 in the circular motion. A connecting arm 38 is fixed to the needle bar support shaft 5 rotatably supported by the arm machine frame 1 (FIG. 2). One end of the connecting arm is swung by a zigzag generating mechanism. One end of the amplitude rod 39 is connected. The amplitude of the zigzag is controlled by the amplitude stepping motors (S, M), the feed pitch is controlled by the feed stepping motors (F, M), and control data from the CPU (CP) is supplied to each stepping motor. Sent. A drive shaft (not shown) of the sewing machine is rotated by a drive motor (M). Since the present invention has the above-described structure, the needle bar 13 is moved up and down in conjunction with the rotation of the drive shaft, and is moved in an arc by the zigzag generating mechanism so that the amplitude of the needle bar 13 is increased via the needle bar support 9. Exercise. The threading device comprises a threading frame 18 and a threading shaft 2.
3 and a compression coil spring 27, a threading hook 31, and the like, and are mounted on the needle bar support 9. Therefore, the threading device is swung with the circular motion of the needle bar support 9, but the threading shaft 23 is formed by the circular groove 3 of the cam plate 3 fixed to the arm machine frame 1.
4, the needle bar 13 and the threading shaft 23 are always kept at a constant distance. Next, the method of using the threading device will be described. First, the operation of the sewing machine is stopped with the needle bar or the balance stopped substantially near the top dead center, and the operation unit 28 of the threading device is grasped with a finger and turned downward. When operated, the pin shaft 26 of the threading shaft 23 is
The abutment of the threading shaft 23 is stopped by abutting against the tip 33 of the second. The pin shaft 24 fixed to the threading shaft 23
Is engaged with the cam groove 25 of the threading frame 18, the direction is slightly changed as it descends, and the threading shaft 23 is rotated, so that the threading hook 31 of the hook support arm 29 is Is inserted into The threading hook 31 inserted into the needle med 30
By pulling the upper thread and pulling the threading hook 31, the thread is introduced into the needle med 30. When the finger is released from the operation unit, the threading shaft 23 returns to the original position by the action of the compression coil spring 27. The threading device of the present invention is supported by the needle bar support 9 and is swung together with the needle bar support 9. The threading device of the threading device fitted on the arm 12 above the needle bar support 9 is provided. The hole 34 of the upper arm 19 of the threading frame 18 forms a narrow groove 35 in the diameter direction larger than the diameter of the hole, and the threading frame 18 is formed of a plastic material so that it has elasticity. I have. Accordingly, there is no backlash in the diameter direction between the outer diameter of the stepped portion and the generation of noise is reduced. In addition, since the positioning member 32 is fixed to the needle bar 13, the movement including the needle bar 13 which moves up and down is performed. Although the mass is increased, the leaf spring 36 is interposed between the lower arm portion 12 of the threading frame 18 and the lower arm portion 12 of the needle bar support 9, so that the inertia of the vertical movement of the needle bar is generated. The impact in the thrust direction is absorbed by the spring 36, and the generation of noise is reduced. Since the embodiment of the present invention has the above-described structure and operation, the threading operation can be performed extremely easily. Noise is likely to be generated between the frame 18 and the needle bar support 9 supporting the threading frame. However, the hole 34 of the upper arm 19 of the threading frame has a narrow groove 35 which is long in the diameter direction. , 35, which are always compressed with a slight force against the shaft diameter of the stepped portion, so that there is no backlash, and a spring 36 is provided between the lower arm 19 of the thread passing frame and the stepped portion of the needle bar support 9. Since it is interposed, it has an absorptive power to the impact in the thrust direction, so that the impact sound is reduced, so that it is excellent in the practical effect and the effect of quieting the environment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention. FIG. 1 is a front view of the present invention, FIG. 2 is a side view of the present invention, and FIG.
FIG. 2 is a plan view of the present invention cut in FIG. DESCRIPTION OF SYMBOLS 1 ... Sewing machine frame 5 ... Needle bar support shaft 9 ... Needle bar support 12 ... Arm 13 ... Needle bar 17 ... Needle 18 ... Threading frame 19 ... Arm 30 ... Needle med 34 ... Hole 35 ... Narrow groove 36 ... leaf spring

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-54979 (JP, A) JP-A-57-139395 (JP, A) JP-A-5-44083 (JP, U) 9891 (JP, Y1) Jigyo Sho 55-34067 (JP, Y1) Jigyo Sho 56-37513 (JP, Y1) (58) Field surveyed (Int. Cl. ⁷ , DB name) D05B 87/00-87 / 02

Claims (1)

(57) [Claim 1] A needle bar support shaft supported by a sewing machine frame,
A needle bar support, which is held by the needle bar support shaft and is restricted in vertical movement and is swingable, is supported by a pair of upper and lower arms extending from the needle bar support so as to be vertically movable. A needle bar, a threading shaft provided with an operation unit and a threading hook are supported so as to be vertically movable, and a pair of upper and lower arms provided at one end are provided on each arm of the needle bar support for supporting the needle bar. A threading frame to be fitted, one end of which is fixed to the threading frame and the other end of which is fitted to the lower arm of the needle bar support, and the lower surface of the arm and the arm of the threading frame. And a spring means interposed between the threading frame body and a hole provided in the upper arm of the threading frame body is slidably fitted to the upper arm of the needle bar support, and A zigzag sewing machine, characterized in that a spring means absorbs an impact in the thrust direction of the needle bar between the threading frame and the needle bar support. Kicking threading device.