JPH0580240B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a thread tying mechanism in a cycle sewing machine that is particularly effective when applied to a lockstitch button sewing machine.

(Prior Art) Various lockstitch and single chain stitch button sewing machines have been proposed as conventional cycle sewing machines, but in particular, in lockstitch button sewing machines, the thread at the end of sewing is cut without thread tying. It was cut by a device etc. In this case, even if a normal tacking operation is performed, fraying occurs and the quality of the sewn product deteriorates. In addition, in the case of the above-mentioned tacking stitch,
A thread knot can only be made when multiple tacking stitches form a hitch stitch, but conventionally it was impossible to actively make a hitch stitch.

(Problems to be Solved by the Invention) The present invention solves problems such as thread fraying at the end of sewing in conventional lockstitch button sewing machines in particular, and provides a thread tying mechanism that can securely tie threads. This is what we are trying to provide.

[Structure of the invention]

(Means for Solving the Problem) Therefore, the present invention uses the rotation of the feed cam shaft, which rotates once per cycle, to control the button hole through the left and right feed cams, front and rear feed cams, and feed base attached to the feed cam shaft. A cycle sewing machine that has a feed plate that moves forward and backward and left and right to the center of the needle drop by the pitch, has a thread tying cam that is fixed to the feed cam shaft and has a protrusion on the outer periphery, and a pin screw that is pressed against the outer periphery of the cam. However, when the pin screw rides on the protrusion, the cam lever swings around a fulcrum, is connected to the cam lever, moves linearly in response to the swing of the cam lever, and when the pin screw passes the protrusion, it instantly a link mechanism that restores its original state, and a movable thread knotting plate connected to the linkage mechanism and capable of reciprocating while being guided by the groove of the feed plate, and when the pin screw of the cam lever rides on the protrusion of the thread knotting,
The movable thread knotting plate moves to forcibly move the lower thread to the right side of the needle drop hole, and this is used as a means for solving the problem.

(Function) When the pin screw of the thread tying cam lever engages with the protrusion of the thread tying cam, the cam lever swings around the fulcrum, converts the link mechanism connected to it into a linear motion, and moves the movable thread tying plate. , and force the bobbin thread near the center of the needle drop hole to the right. At the beginning of the next needle drop, the protrusion of the cam inserts the cam lever pin screw, and the movable thread tying plate is restored, allowing the needle to pass through the needle drop hole, allowing the needle to pass through the bobbin thread. Since it passes on the left side, a hit stitch is generated.

(Example) Examples of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show examples of the present invention,
FIG. 1 is a plan view, and FIG. 2 is a side view. Now 5
4 is a feed camshaft that rotates once per cycle.
A left and right feed arm 53 is attached to a left and right feed cam 58 mounted on the shaft 54, and a feed roller pin screw 47 attached to the tip of the arm 53 is engaged with a groove 58a of the feed cam 58. There is. Further, the left and right feed arms 53 are pivotally connected to the bed body by the feed arm pins 48, so when the feed cam 58 rotates due to the rotation of the shaft 54, the left and right feed arms 53 move around the pin 48 as a fulcrum via the feed corropin screws 47. Perform a rocking motion.

Reference numeral 46 denotes a longitudinal feed cam, which is attached to the feed cam shaft 54, and a groove 46a of the cam 46 engages with a feed roller pin screw 47a attached to the tip of the longitudinal feed adjuster 49. Also, the regulator 4
9 is pivotally connected to the bed body by a feed arm pin 48a, and swings along the groove 46a around the pin 48a. Further, the left and right feed arms 53 are connected to a feed table 64 via a left and right feed link 57, and the front and rear feed adjuster 49 is connected to the feed table via a first and rear feed link 59 and a second front and rear feed link 63. 64.

The feed plate 64 is centered around a left-right feed adjustment nut 66 and a front-rear feed adjustment piece 50, and the feed plate 40 is operated by combining these left-right feed operations and front-rear feed operations. The movement of the feed plate 40 in the needle drop section of the button sewing machine moves back and forth and left and right to the center of the needle drop by the distance of the button hole pitch. Also, the feed cam shaft 5 to which the left and right feed cams 58 and the front and back feed cams 46 are attached
4 rotates once per cycle (set to 18 stitches in this embodiment), so the operation pattern of the needle drop portion of the feed plate 40 is set as shown in FIG. Fourth
In the figure, 70 is a button, 70a and 70c are button holes on the left side, and 70b and 70d are button holes on the right side. In addition, in Fig. 4, the stitches in the button holes 70a and 70c are all hitch stitches, and 18 stitches are tacking stitches, and the position of the lower thread 71 at the end of 16 stitches is as shown in Fig. 5, and the position of the lower thread 71 at the beginning of 17 stitches. is as shown in Figure 6. Further, 72 is a needle thread, and 73 is a needle drop hole.

Figure 3 A, B, C, and D show the procedure for generating hit stitches in the feed mechanism, and show the button hole 70a on the left side.
A hit stitch is generated by the needle drop in , but in the button feed pattern shown in Figure 4, 3,
5, 7, 12, 14, 16 needles are in the left button holes 70a, 70
Since it comes to c, a hitch stitch is generated.

Reference numeral 30 denotes a thread tying cam attached to the end surface of the feed cam shaft 54, and the cam 30 has a protrusion 30a formed on its outer periphery. Reference numeral 28 denotes a thread tying cam lever which is pivotally attached to the bed main body with a set screw 24, and a cam lever pin screw 29 that contacts the outer periphery of the cam 30 is attached to the tip of the thread tying cam lever 28.
A thread tying link 34 is connected to the lever 28, and when the lever 28 swings, a thread tying intermediate lever 60 connected to the tip thereof swings via the link 34.

The thread tying cam 30 moves the thread tying cam lever 28 with the set screw 24 as a fulcrum when the sewing machine performs a start operation and the pin screw 29 rides on the protrusion 30a of the cam 30 at the end of 16 stitches. oscillate counterclockwise.
An intermediate lever return spring 15 is tensioned between the thread knot intermediate lever 60 and the spring hook 17 attached by the spring hook nut 36, and when the cam lever 28 swings,
The intermediate lever 60 rotates against the return spring 15 using the set screw 60a as a fulcrum. Furthermore, when the protrusion 30a passes through the pin screw 29, the intermediate lever 6 instantly
0 restores.

At the other end of the intermediate lever 60 is a thread-tied intermediate link 5.
5 and an adjustment link 51 are connected to each other, and a movable thread tying plate 43 is connected to the link 51 via a thread tying lever 61. When the cam lever 28 swings, the tip of the movable thread tying plate 43 It approaches the tip of a fixed thread knotting plate 42 which is superimposed thereon and provided by a thread knotting plate support 41. Movable thread knotting plate 4
3 is a fixed thread knotting plate 4 in a groove on the back side of the feed plate 40 so that the hook part 43a at the tip is attached to the needle drop part.
It is guided along with 2. Furthermore, at the end of the 16th stitch, the movable thread knotting plate 43 is in a position where it closes the needle drop hole 73 as shown in FIG.
When the pin screw 29 rides on a, the cam lever 28 swings, and the movable thread tying plate 43 moves, the bobbin thread 71, which was near the center of the needle drop hole 73, is forced to the right side of the needle drop hole 73, as shown in FIG. move the target. In addition, 38 is a feed plate washer, 39 is a feed plate set screw, 44 is a throat plate, and 45 in FIG. 3 is a hook.

At the beginning of the 17th stitch after the sewing machine is started, the protrusion 30a of the thread tying cam 30 passes through the pin screw 29 of the thread tying cam lever 28. Therefore, due to the restoring force of the intermediate lever return spring 15, the movable thread knotting plate 43 moves to the position shown in FIG. A hit stitch is generated. The condition for forming a thread knot is when the thread is in the tacking state (16th and 17th stitches in Fig. 4), and the tacking stitches are made several times in succession, and then the thread is cut. FIG. 7 shows a state in which hit stitches have been performed twice.

In addition, in the figure, 1 is the rotary leaf, 2 is the external play set screw, 3 is the oil drain collar, 4 is the hook shaft bushing, 5 is the hook shaft, 6 is the hook shaft collar, 7 is the hook shaft spacer, and 8 is the hook shaft bush. , 9 and 14 are helical gears, 10 is a lower shaft washer set screw, 11 is a lower shaft positioning washer, 12 is a lower shaft bush, 13 is a ball bearing, 16 is a lower shaft, 18 is a threaded gear, and 19 is a threaded gear set screw. , 20 is warm, 2
1 is a bearing receiver, 22 is a ball bearing with a collar, 23 is a ball bearing washer, 25 is a stop arm, 26 is a thread knot cam washer, 27 is a thread knot cam set screw, 31 is a stop arm roller set screw, 32 is a stop arm Koro, 33 is the stitch number adjustment wheel,
Reference numeral 35 designates a front and rear feed link, 37 a front and rear feed link set screw, 52 a worm gear, 56 a left and right feed link set screw, 62 a screw gear, 65 a left and right feed instruction plate, and 67 a feed platform guide plate.

〔Effect of the invention〕

Since the present invention is configured as described in detail above, when a tacking stitch is performed, the thread knot becomes a hit stitch. The prerequisite for occurrence of a hit stitch is that if the needle faces the front of the hook and is on the left side of the bobbin thread, a hit stitch structure will normally occur. is moved to the right side by the hook at the tip of the movable thread knotting plate, so the seam formation at the end of sewing becomes a hit stitch even in the tacking stitch state, and the thread at the end of sewing becomes unraveled like in conventional lockstitch button sewing machines. There are no defects that reduce quality.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a thread tying mechanism in a cycle sewing machine showing an embodiment of the present invention, Fig. 2 is a side view of the same, Figs. Fig. 4 is an explanatory diagram showing the button feeding pattern of the feeding plate, Figs. 5 and 6 are explanatory diagrams showing the moving state of the movable thread knotting plate, and Fig. 7 is an explanatory diagram showing the state in which hit stitches have been performed twice. It is. Explanation of the main parts of the figure, 28... Thread knotting cam lever, 29... Pin screw, 30... Thread knotting cam, 3
0a...Protrusion, 34...Link, 40...Feed plate, 42...Fixed thread knotting plate, 43...Movable thread knotting plate, 46...Back and forth feed cam, 54...Feed cam shaft, 58... Left and right feed cam, 64... feed base.

Claims (1)

[Claims] 1. A feed plate that moves by the pitch of the button hole back and forth to the left and right to the center of the needle drop through the left and right feed cams, front and rear feed cams, and feed base attached to the feed cam shaft, which rotates once per cycle. A cycle sewing machine having a thread tying cam fixed to the feed cam shaft and having a protrusion on the outer periphery, and a pin screw pressed against the outer periphery of the cam, and when the pin screw rides on the protrusion, the thread tying cam has a fulcrum. a cam lever that swings at the center; a link mechanism that is connected to the cam lever and moves linearly in response to the swing of the cam lever; and that returns to its original state instantaneously when the pin screw passes through the protrusion; When the pin screw of the cam lever rides on the protrusion of the thread tying cam, the movable thread tying plate moves to tie the bobbin thread to the right side of the needle drop hole. A thread knotting mechanism in a cycle sewing machine, which is characterized by forcibly moving the thread.