JP2660402B2 - Needle thread cutting device in embroidery sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to an embroidery sewing machine for cutting an upper thread for changing a place for performing embroidery sewing or changing a color of an upper thread for embroidery sewing. The present invention relates to a needle thread cutting device in an embroidery sewing machine. (Prior Art) In a conventional upper thread cutting device, a member for removing a lower thread to prevent erroneous cutting of a lower thread and a member for hooking a loop of an upper thread formed by the action of a shuttle. Also, there is known an apparatus provided with a movable blade for cutting a needle thread hooked on the member. (Problems to be Solved by the Invention) However, the above-described apparatus having a movable blade has a complicated structure, is expensive, and has a problem that the drive unit of the movable blade often suffers a failure. This invention eliminates the above conventional problems and eliminates erroneous cutting of the lower thread, and can cut only the upper thread accurately,
An object of the present invention is to provide an upper thread cutting device in an embroidery sewing machine which has a simple configuration, can be provided at low cost, and can reduce the chance of occurrence of a failure. The configuration of the present invention is as follows. (Means for Solving the Problems) The needle thread cutting device in the embroidery sewing machine according to the present invention includes a shuttle below the needle plate having the needle through hole, and the needle through hole above the needle plate. A needle that can be moved up and down so as to be able to descend toward the shuttle, and by rotating the shuttle and moving the needle up and down, the needle is fed out through the needle and passes through the shuttle by the rotation of the shuttle. In an embroidery sewing machine in which embroidery sewing is performed on a cloth with a thread and a lower thread unwound from a shuttle, on the lower side of the needle plate, a hook rod and an upper thread hooked on the hook rod are moved from the hook rod. A hook consisting of a hook attached to the tip of the hook is arranged near the hook to prevent the hook from coming off. Before passing through the front, The upper thread is advanced to a position where the upper thread is to be moved, and a part of the upper thread tries to pass through the front side of the shuttle so that the upper thread is hooked on the hooking rod of the hooking piece. After passing through the front side of the shuttle, it is possible to move backward and forward from the advanced position, and in the process of further retreating, the upper thread hooked on the hooking piece is pulled by the cutting blade. A cutting blade was fixedly provided on the hooking piece so as to be cut. (Operation) Before the part of the upper thread that passes through the hook by the rotation of the hook passes through the front side of the hook, the hooking piece advances to the thread movement position on the front face of the hook. Thereafter, a part of the upper thread tries to pass on the front side of the shuttle, so that the upper thread is hooked on the hooking piece. Thereafter, the hooking piece is retracted from the above position. In this case, the hook at the tip of the hooking piece moves by pulling the upper thread. In the course of the movement, the cutting thread is fixedly provided on the hooking piece so that the upper thread caught in the hooking hole is pulled and cut by the pulling blade. Is cut off when approaching. (Embodiment) Drawings showing an embodiment of the present application will be described below. First
In FIG. 5 to FIG. 5, F is a base frame of the embroidery sewing machine, 1 is a needle plate having a needle passage hole 1a, and 2 is a shuttle located below the needle plate 1 so as to be rotated by a shaft 50. An outer hook 3 and an inner hook 5 housed in the outer hook 3 and prevented from rotating by a fixed hook stopper 4 are configured in a known manner. A bobbin case 6 for a bobbin for a lower thread is housed in the inner hook 5. 6a shows a yarn guide. Reference numeral 7 denotes a needle disposed above the needle plate 1, which is vertically movable so as to be able to descend through the needle passage hole 1a as is well known. Next, 8 is a mounting plate fixed to the frame F, 9 is a rotary solenoid mounted on the mounting plate 8, and operates in association with the shuttle 2 and the needle 7 according to a command from a control device (not shown). ing. Reference numeral 10 denotes a rotating shaft 9a of the rotary solenoid 9.
A swinging arm 11 is fixed to the swinging arm 10 by a hooking piece. Reference numeral 11a denotes a hook rod of the hook piece, which is formed to be narrow as shown. 13 is the catch rod
The claw attached to the tip of 11a prevents the upper thread hooked on the hooking rod 11a from coming off from the hook. The hooking piece 11 is retracted from the shuttle 2 as shown in FIG. 1 by a reciprocating rotation of the rotation shaft 9a, and a second position.
As shown in FIG. 3 and FIG. 3, the claw 13 is movable between a hooking position where the claw 13 enters the hook 2 and
The rotary solenoid 9 constitutes a driving means for moving the hooking piece 11 between the above-mentioned two positions. Incidentally, the driving means may be a motor capable of rotating forward and backward. The hooking position of the hooking piece 11 is set at a position where the claw 13 is immersed in the hook 2 as seen from above as clearly shown in FIG.
Reference numeral 15 denotes a cutting blade for cutting the upper thread, which is fixed to the claw 13 by a fixing means such as brazing or an adhesive. In the above configuration, when the upper thread b is passed through the hole of the needle 7 and the bobbin of the lower thread a is set in the bobbin case 6 and the embroidery sewing machine is operated, the needle 7 is moved up and down through the needle through hole 1a. The embroidery stitch 17 can be applied to the cloth 16 in a known manner by rotating the outer hook 3 together. During this normal sewing, no operation command is given to the solenoid 9,
The hook piece 11 remains in the retracted position in FIG. Next, when the upper thread b is to be cut after the embroidery sewing of one pattern has been completed, for example, when the embroidery sewing of another pattern is to be performed, an operation command is given to the solenoid 9 and the hook piece 11 is moved to the position shown in FIG. The upper thread b is cut in association with the needle 7 and the shuttle 2 at the timing shown in FIG. That is, at the time when the cycle angle is 0 ° (a), the hooking piece 11 moves from the retreat position to the hooking position. Thereafter, the rotation of the outer hook 3, the vertical movement of the needle 7, and the vertical movement of the balance are continued as usual. When the cycle angle reaches 205 °, the needle 7 is lowered through the cloth 16 and the needle passage hole 1 a. The thread b is hooked by the point 3a of the outer hook 3.
Thereafter, as the outer hook 3 continues to rotate, the upper thread b hooked on the blade point 3a forms a loop and passes through the inner hook 5. In the process, the portion of the loop of the upper thread b that passes through the front side of the shuttle is one edge 11a 'of the hooking rod 11a at the time before the loop is maximized (for example, at a cycle angle of 290 °). Contact Thereafter, when the cycle angle reaches 353 degrees, the upper thread b finishes passing through the inner hook 5, and the upper thread b
Is lifted upward (by a balance) off the point 3a. As a result, as shown in FIG.
It becomes a state caught in a. Next, at time (b), the hooking piece 11 is retracted from the hooking position toward the retreat position. In the process, when the cutting blade 15 emerges from the shuttle 2 as shown in FIG. 5, the upper thread b is cut by the cutting blade 15. Since this cutting step is performed in the process of raising the balance as shown in FIG. 6, that is, in a state where the upper thread b is taut,
The upper thread b is reliably cut. When the cutting of the upper thread b is completed as described above, the operation of the shuttle, the needle, and the balance is stopped, the cloth 16 is moved for embroidery sewing at the next place, and the color change of the upper thread is well known. Done. Next, when the hook piece 11 is moved from the retracted position to the hook position, the upper thread is wound around the hook piece 11 when the last stitch of the normal sewing is formed as shown by A in FIG. From the time after moving to a position where it does not stick (the time after the portion of the upper thread loop passing the front side of the hook has passed the hooking position of the hooking piece 11), passing the front side of the hook in the loop of the upper thread. This may be performed at any time before the portion passes through the hooking position of the hooking piece 11. Further, the movement from the hooking position to the retreating position starts from the time when the portion passing through the front side of the shuttle in the loop of the upper thread comes into contact with one edge 11a 'of the hooking rod 11a as shown by B in FIG. There may be three stitches from the last stitch formation, and it may be performed at any time before the hook piece 11 can be moved away from the hooking position before the upper thread b is hooked doubly on the hooking rod 11a. Next, FIGS. 7, 8 and 9 showing different embodiments of the present invention will be described. These figures show different examples of means for fixedly providing the cutting blade on the hook piece 11,
7 and 8 show an example in which the cutting blade 15 is fixed to the claw 13 with a rivet 18, and FIG. 9 shows an example in which a part of the claw 13 is sharpened to form the cutting blade 15. (Effects of the Invention) As described above, in the present invention, when it is desired to cut the upper thread b that has penetrated the cloth 16 toward the shuttle 5 under the needle plate 1, Before a part of the thread b passes the front side of the shuttle 5, the hooking piece 11 is advanced to a position close to the front face of the shuttle 5 so that a part of the upper thread b tries to pass the front side of the shuttle 5. Then, the upper thread is hooked on the hooking rod 11 of the hooking piece 11.
a), after a point in time when a part of the upper thread b passes on the front side of the shuttle 5, the hooking piece 11 is retracted from a position close to the front of the shuttle, and in the process of retreating thereafter. There is a feature that the upper thread b hooked on the hooking piece 11 can be cut in a stretched state. This means that the lower thread a may be accidentally cut or the lower thread a
This has the effect that only the upper thread b can be cut accurately without affecting the upper thread b. In addition, since the tension is applied only to the upper thread b by moving the hook piece 11 forward and backward as described above, the configuration may be extremely simple, that is, the cutting blade 15 is fixedly provided on the hook piece 11,
Since it is not necessary to separate the hooking piece 11 from the hooking piece 11, the configuration is simplified, and it is possible to provide an inexpensive product, and to minimize the chance of occurrence of a failure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention. FIG. 1 is a perspective view showing a shuttle of an embroidery sewing machine and members provided in the vicinity thereof.
FIG. 3 is a view showing a state in which the hooking pieces have been moved to the hooking position in FIG. 1, and FIG. 3 is a plan view showing a relationship between the shuttle, the hooking pieces, the upper thread and the lower thread in the state of FIG. 4 is a front view of the same, FIG. 5 is a plan view showing a state where the hooking pieces have started to retreat from the state of FIG. 3, FIG. 6 is a time chart, and FIG. FIG. 8 is a plan view showing a different example, FIG. 8 is a partially cutaway front view of FIG. 7, and FIG. 9 is a plan view showing still another example of a means for attaching a cutting blade to a hook piece. 1. Needle plate, 1a Needle threading hole, a ... lower thread, b ... upper thread, 11 ... hooking piece, 11a ... hooking rod, 13 ... claw.

Claims (1)

(57) [Claims] While equipped with a shuttle below the needle plate having a needle passage hole,
Above the needle plate, there is provided a vertically movable needle that can be lowered toward the shuttle through the needle passage hole. By rotating the shuttle and moving the needle up and down, the needle is passed through. In an embroidery sewing machine in which an embroidery sewing is performed on a cloth by an upper thread that is fed and passed through the hook by the rotation of the hook and a lower thread that is fed from the hook, a hooking rod is provided on a lower side of the needle plate. In order to prevent the upper thread hooked on the hooking rod from coming off the hooking rod, a hooking piece consisting of a hook attached to the tip of the hooking rod is arranged near the hook, and the hooking piece is Before a part of the upper thread passing through the front side of the shuttle, a part of the upper thread advances to a position where the upper thread is to be moved on the front side of the shuttle and a part of the upper thread passes through the front side of the shuttle. The upper thread is hooked on the hooking rod of the hooking piece After a point in time when a part of the upper thread passes through the front side of the shuttle, the upper thread can be moved back and forth from the advanced position, and in the process of further retreating, the upper thread hooked on the hooking piece An upper thread cutting device in an embroidery sewing machine, wherein a cutting blade is fixedly provided on the hooking piece so that the hook is pulled and cut by the cutting blade.