JPH0720180U - Draw-out cam for looper thread in double chain stitch sewing machine - Google Patents

Abstract

(57) [Abstract] [Purpose] A thread reeling device in which the looper thread is fed out by slidingly contacting the looper thread with the peripheral surface of a cam plate rotating between two thread guides. In a double chainstitch sewing machine having a double loop stitch sewing machine, when the looper thread is cut, it is effective that the loose cutting thread end falls between the thread guide and the cam and contacts the cam shaft, and winds around the shaft. To provide a simple device that can be blocked. [Structure] A cover having at least one side surface made of a flexible material is fixed to a machine frame, and the vicinity of a mounting portion of a cam plate on a rotating shaft is shielded by the cover.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention is a double chain stitch having a thread take-up device in which the looper thread is slidably contacted with the peripheral surface of a cam plate which rotates between two thread guides to control the amount of delivery of the looper thread. The present invention relates to a device for preventing looper yarn from being wound around a yarn feeding cam shaft in a sewing machine.

[0002]

[Prior art]

 A looper thread feeding device in a sewing machine in which a double loop stitch is formed by a looper thread and a needle thread usually has a rotary cam that is projected and retracted between two thread guides provided in a bed of the sewing machine. The looper thread is slidably brought into contact with the peripheral surface of the cam plate to control the thread delivery amount. However, when the thread is cut during sewing or when the thread is cut again before and after the sewing work and sewing is restarted, if the thread end is loose, the thread end falls between the thread guide and the cam and the cam rotates. If it continues to be sewn without noticing it, the thread is pulled out from the supply source side and the amount of winding increases, and the work efficiency is greatly reduced to remove this. Furthermore, in a tubular bed sewing machine for sewing a tubular material, it is very difficult to remove the wound thread because the space inside the bed is narrow.

In order to prevent the winding, for example, Japanese Patent Publication No. 3-69557 discloses a device in which the gap between the outer surface of the cam and the yarn path mounting plate is closed by a yarn holding material such as a mold. In this case, however, in some cases, the yarn passes along the cam surface through the gap in the block and reaches the cam shaft. If the shaft continues to rotate while being in contact with the shaft, it may become entangled with the shaft, that is, there is a problem that winding around the shaft cannot be surely prevented. Further, in US Pat. No. 4,492,174, there is a problem. Although a device in which air is blown to a portion to prevent wrapping is disclosed, equipment such as a compressor and a device for controlling the jetting time of the air flow are required, and the air flow causes the yarn path to pass. There was a concern that .

[0004]

[Problems to be solved by the device]

 Therefore, the object of the present invention is to prevent the loose cutting thread end from falling down between the thread guide and the cam and reaching the cam shaft at the time of cutting the looper thread, and to prevent the winding around the shaft. An object is to provide a simple device that can effectively block.

[0005]

[Means for Solving the Problems]

 That is, this invention is a double chain stitch sewing machine having a thread take-up device in which a looper thread is slidably brought into contact with the peripheral surface of a cam plate which rotates between two thread guides so as to control the thread take-out amount. In the first aspect, the first feature is that a cover having at least one side surface made of a flexible material is fixed to the machine frame, and the vicinity of the mounting portion of the cam plate on the rotating shaft is shielded by the cover.

Another feature of the present invention is that the cover is formed of a metal plate on which a sponge-like material is stuck, and the sponge-like material sticking surface is placed close to the rotary shaft.

Further, in the case where two cam plates are arranged in parallel and a yarn pressing lever is provided between them to control the yarn feeding amount, a cover is provided between both cam plates and both cam plates. The effect can be ensured by covering the shaft of the outer part.

[0008]

[Action]

 Even if the loose thread end falls between the thread guide and the cam when the thread is cut during sewing with the double chain stitch sewing machine or when sewing is resumed after cutting the thread before and after the sewing work, the cam Since the vicinity of the attachment part of the cam to the rotary shaft is covered by the cover, the yarn end is held in the vicinity, and it prevents long hanging in the free state and coming into contact with the shaft. It does not cause wrapping. Since the surface of the cover is made of a flexible material, the cover can be brought into close contact with the surfaces of the rotating shaft and the cam to enhance the shielding effect, and the cover can be easily installed without requiring high accuracy.

Further, the cover is formed by laminating a metal plate and a sponge-like material together, so that the stability of the position and shape and the shielding property can be secured, and further, two rotating cam plates are provided. In this case, the effect of preventing wrapping can be further enhanced by shielding the rotary shaft between the cam plates with the cover.

[0010]

【Example】

 An embodiment of this invention will be described with reference to FIGS. FIG. 1 shows an essential part of a double chain stitch sewing machine 4 having a tubular bed 3 provided with three needles 1 and one looper-2. The needle thread 6 supplied through the thread 5 and the looper thread 8 which is also supplied through the thread tension device 7 form a double chain stitch in three rows. In the cylindrical bed 3, a yarn reeling device 9 for controlling the amount of delivery of the looper yarn 8 is installed.

This thread reeling device 9 is installed on the machine frame of the sewing machine 4 above the lower shaft 10 as shown in FIG. 2 and two clam-shaped cam plates 11 and 11 fixed to the lower shaft 10 of the sewing machine 4. The thread guide 13 having a gap 12 for retracting the cam plate 11 and inclined so that the front side is lowered, and a lever-like thread guide 14 installed on the thread guide 13 and extending upward between two cam plates 14. And the yarn paths 15 and 15 provided on both sides of the gap 12, respectively, the amount of protrusion of both cam plates 11 from the gap of the thread guide 13 changes as the lower shaft 10 rotates.

Further, as shown in FIGS. 3 and 4, a cover 16 is arranged in the vicinity of a mounting portion of the cam plate 11 below the thread reel 13 to the lower shaft 10. The cover 16 is made of a metal plate 18 having a sponge 17 attached to the lower surface thereof, and is of a fork type so as to cover the space between the cam plates 11 and 11 and the lower shaft 10 on both outer sides thereof from above, and to form a base 19 Is fixed to the frame 20 of the sewing machine with screws 21.

In this embodiment, a metal plate with a sponge attached is used as the cover, but the entire cover may be made of an elastic material such as rubber. Considering the shape and mounting position so that the lower shaft and the portion of the cam where the thread is easily wound can be sufficiently shielded. It goes without saying that it may be installed in a position.

In the sewing machine configured as described above, the looper yarn 8 is formed from the thread tension device 7 to the eyelet 22 of the thread passage 15 on the right side and the outer peripheral surface of the cam plate 11 on the right side as shown by an arrow A in FIG. The bent state is guided by the lower surface of the lever-shaped yarn guide 14, the outer peripheral surface of the left cam plate 11, and the eyelet 22 of the left yarn path 15 into the bent state. When the sewing machine is operated, the cam plate 11 rotates in the direction of arrow B together with the lower shaft 10, and the bending shape of the looper yarn 8 changes in accordance with the change in the protrusion amount of the cam plate protruding from the gap 12 of the thread guide 13. Changes and the amount of yarn feeding out is controlled.

When the looper thread 8 is cut during sewing or the looper thread 8 cut before and after sewing becomes loose, the cut end of the looper thread 8 becomes free. Even if the cam plate 11 falls into the gap 12 of the thread reel 13 as the cam plate 11 rotates, the attachment portion of the cam plate 11 to the lower shaft 10 is shielded by the cover 16, so that the lower shaft 10 is prevented from being wound. It Even if the yarn end reaches the lower shaft 10 by passing between the cover 16 and the cam plate 11, the cover 16 hangs down because it is near the lower shaft 10. The length of the yarn is short, and therefore, the yarn does not run on the rotating lower shaft 10 and become entangled.

[0016]

[Effect of device]

 As described above, the present invention can prevent the looper thread from being wound around the thread winder with an extremely simple device, and the thread is cut during sewing by the double chain stitch sewing machine, and Even if the loosened thread end falls between the thread guide and the cam when sewing is resumed after cutting the thread in the front and back, it is slackened because the vicinity of the cam attachment part to the rotary shaft is covered by the cover. Since the yarn end is held by the cover in the vicinity thereof and prevents the yarn end from hanging down in the free state and coming into contact with the rotary shaft, the yarn end is not transferred to the shaft to cause winding. Since the surface of the cover is made of a flexible material, the cover can be brought into close contact with the surface of the shaft or cam to enhance the shielding effect, and it does not require high mounting accuracy at the installation position.

Further, the cover is formed by laminating a metal plate and a sponge-like material together, so that the stability of the position and shape and the shielding property can be secured, and further, two rotating cam plates are provided. In the case of the product, the effect of preventing wrapping can be further enhanced by shielding the shaft between the cam plates with the cover.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a sewing machine using an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the embodiment.

FIG. 3 is likewise a vertical cross-sectional view of the main part thereof.

FIG. 4 is a partial side sectional view of the same main portion.

[Explanation of symbols]

1 needle 2 looper 3 tubular bed 4 double chain stitch sewing machine 5, 7 thread tensioner 6 needle thread 8 looper thread 9 thread reel 10 lower shaft 11 cam plate 12 gap 13 thread guide 14 thread guide 15 Thread path 16 Cover 17 Sponge 18 Metal plate 22 Eyelet

Claims (3)

[Scope of utility model registration request] 1. A double having a thread take-up device for controlling the amount of delivery of the looper thread by slidingly contacting the looper thread with the peripheral surface of a cam plate rotating between two thread guides. In a chain stitch sewing machine, a cover, at least one side of which is made of a flexible material, is fixed to a machine frame, and the vicinity of a portion where a cam plate is attached to a rotary shaft is shielded by the cover.
A device to prevent the winding of the par thread around the thread feeding cam shaft. 2. The yarn feeding camshaft for looper yarn according to claim 1, wherein the cover is made of a metal plate to which a sponge-like material is pasted, and the sponge-like article pasting surface is installed close to the rotary shaft. Device to prevent wrapping around. 3. The looper yarn according to claim 1, wherein the two cam plates are arranged in parallel, and the cover is installed so as to cover the shafts between both cam plates and both outer portions. A device to prevent winding around the payout cam shaft.