JPH0567317B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a multi-needle sewing device used in the manufacture of tatami floors, etc. The amount can be set to any size, and the lower end position of the stroke is maintained at a substantially constant height when changing the stroke amount.

(Prior technology) As a sewing device for performing multiple rows of single chain stitches on objects to be sewn, such as tatami floors, a widthwise long needle base with multiple sewing machine needles fixed downward is positioned on both the left and right sides. The needle rest is guided by a vertical guide that moves up and down, and the needle rest is raised and lowered via a pair of left and right connecting rods that reciprocate up and down by transmission from a lower cam or crank, etc., in synchronization with the raising and lowering movement of the needle rest. There is a known sewing machine in which an object to be sewn, such as a tatami floor, which is fed forward in the downward direction of the needle stand, is sewn using the above-mentioned sewing needle.

As a means for changing the vertical stroke of the needle rest in such a multi-needle sewing device according to the thickness of the material to be sewn, a plurality of pin holes are drilled along the length of the crank. It is known to replace the connecting pin with the connecting rod depending on the thickness of the item to be sewn, and to adjust the length of the connecting rod to maintain a constant height of the bottom dead center of the sewing machine needle. In addition, in this type of single chainstitch sewing machine, the sewing operation is performed by hooking the thread to the sewing machine needle near the bottom dead center of the sewing machine needle, so when changing the vertical stroke of the needle rest, the bottom dead center position must be changed. It is necessary to change the top dead center position without changing the top dead center position.

Further, a horizontally movable table is provided below the fixed guide plate that supports and guides the object to be sewn from below, and a pair of left and right swinging levers are provided on the horizontally movable table so as to be vertically swingable. The lower ends of the connecting rods at both ends are guided vertically up and down, and the lower ends of the connecting rods are slidably connected to a guide provided along the length of the swinging lever, so that the swinging lever can be moved up and down. While the needle rest is raised and lowered by rocking, by changing the front and back position of the horizontal moving stage, the connection position of the lower end of the connecting rod to the guide of the rocking lever is changed, thereby improving the bottom dead center when the needle rest goes up and down. It is known to change the lifting stroke without changing the height (see Japanese Patent Laid-Open No. 1-285289).

(Problem to be Solved by the Invention) However, since the means for replacing the connecting pin between the crank and the connecting rod requires replacing the pin and adjusting the length of the connecting rod, it is necessary to change the setting of the lifting stroke. The work for this was troublesome. In addition, the means for driving the needle rest via a connecting rod using a swinging lever provided on the horizontal moving table makes it easy to change the setting of the elevating stroke, but the mechanism for elevating the needle rest is different from the conventional one. The problem is that this mechanism is fundamentally different from a mechanism that uses a crank, a cam, etc., and is more complicated than the conventional mechanism.

This invention makes it easy to change the setting of the lifting stroke, maintains the height of the bottom dead center almost constant during the change, and has a simple mechanism, allowing conventional cranks, cams, etc. to be used as is. The purpose of this invention is to provide a multi-needle sewing device that can.

(Means for Solving the Problems) The device of the present invention (see Fig. 1) has a plurality of sewing machine needles 2 fixed downward, and widthwise long needles that are movable up and down along a vertical guide 4. The base 1 is raised and lowered via a pair of left and right connecting rods 7 that are driven up and down, and the sewing machine needle 2 performs multiple rows of single chain stitches on the workpiece that is fed forward and backward below the needle base 1. In the multi-needle sewing device,
Between the end of the needle rest 1 and the upper end of the connecting rod 7,
A swinging lever 10 that can swing vertically and has a fulcrum 13 that can swing back and forth is interposed, and a sliding block 15 that can be fixed at any position in the length direction is attached to this swinging lever 10. swing lever 10
The upper end of the connecting rod 7 is connected to one side of the sliding block 15 by a connecting pin 20 in the width direction, and the end of the needle rest 1 is connected to the other side by a connecting pin 25 in the width direction (see Fig. 2) so as to be rotatable. It is characterized by being connected.

(Function) As the connecting rod 7 moves up and down, the up and down movement is transmitted to the needle rest 1 via the connecting pin 20, the swing lever 10, the sliding block 15, and the connecting pin 25, and the needle rest 1 moves in the vertical direction. A vertical movement of a fixed stroke is performed along the guide 4, and at this time, the fulcrum 13 of the swing lever 10 swings back and forth. and,
When the upper end of the connecting rod 7 and the sliding block 15 overlap, the up-down stroke of the needle rest 1 matches the up-down stroke of the joining rod 7, but the upper end of the joining rod 7 swings more than the needle rest 1. When the lever 10 is located on the fulcrum 13 side, the vertical stroke of the connecting rod 7 is expanded and the vertical stroke of the needle rest 1 becomes large.On the other hand, when the upper end of the connecting rod 7 is located on the opposite side, the vertical stroke of the connecting rod 7 is reduced, and the vertical stroke of the needle rest 1 becomes smaller. Furthermore, when the upper and lower end positions of the vertical stroke are symmetrical with respect to the horizontal line passing through the fulcrum 13 of the swing lever 10, the connecting rod 7
The amount of change in the upper and lower end positions of the lifting stroke due to the change in the upper end position becomes equal, but when the lower end position of the lifting stroke rises and approaches the above horizontal line, the lower end position of the lifting stroke hardly changes, and the upper end Only the position changes significantly. Therefore, the locus of movement of the fulcrum 13 of the swinging lever 10 is set slightly downward with respect to the horizontal line, and the locus of movement of the bottom dead center of the connecting rod 7 is set close to the locus of movement of the fulcrum 13 of the swinging lever 10. By doing so, it becomes possible to increase or decrease the lifting stroke without changing the lower end position of the lifting stroke.

(Example) In FIG. 1, a needle rest 1 is formed to be long in the machine width direction, and a large number of single chainstitch sewing machine needles 2 are fixed downwardly at regular intervals along the lower surface of the needle rest 1. A vertical guide shaft 4 fixed to a frame (not shown) is slidably inserted into the lifting block 3 fixed to the end, and the needle rest 1 is guided by this guide shaft 4. It is designed to rise and fall vertically. A main shaft 5, which is long in the width direction and rotates by a motor drive, is provided below the needle rest 1, and the lower end of a long connecting rod 7 is connected to a pin 8 at the tip of a crank 6 fixed to the end of the main shaft 5. The upper ends thereof extend upward.

A swing lever 1 is connected between the upper end of the connecting rod 7 and the lifting block 3 fixed to the end of the needle rest 1.
0 intervenes. This swinging lever 10 is provided facing forward and backward, and one end thereof is connected to the upper end of a swinging arm 12 with a lower support shaft 11 as a fulcrum by a pin 13, and this pin 13 can swing forward and backward. This pin 13 constitutes a fulcrum for the vertical swing of the swing lever 10. A slot 14 is formed in the swing lever 10 along its length, and a sliding block 15 is slidably fitted into the slot 14. A longitudinal adjusting screw 16 connected to the oscillating lever 10 is screwed into the free end 17 of the swing lever 10, and a locking nut 18 is mounted on its projecting end. That is, by turning the adjusting screw 16, the sliding block 15 is moved in the longitudinal direction of the swinging lever 10, and by tightening the lock nut 18, the sliding block 15 is fixed at a desired position on the swinging lever 10.

A U-shaped pin plate 19 that straddles the slot 14 is fixed to the center of the swing lever 10, and the upper end of the connecting rod 7 is fixed to this pin plate 19 by a pin 20 in the width direction. connected. Further, a rear block 3a, which projects from the lifting block 3 of the needle rest 1, is connected to the sliding block 15 by a widthwise pin 25 (see FIG. 2).

In the above structure, when the main shaft 5 is driven,
As the crank 6 rotates, the connecting rod 7 moves up and down, and in conjunction with this, the swinging lever 10 swings up and down using the pin 13 at one end as a fulcrum, and moves through the sliding block 15 and the back block 3a. The lifting block 3 and the needle rest 1 move up and down. At this time, the lifting block 3 moves up and down along the guide shaft 4, so that the movement of the sliding block 15 and the swinging lever 10, which are connected to the lifting block 3 via the back block 3a, is caused by the movement of the lifting block 3. pin 1, which is the fulcrum of the swinging lever 10, is restrained by the movement of
3 swings back and forth along an arc drawn at the upper end of the swing arm 12.

That is, as shown in FIG. 2, when the crank 6 rotates, the lifting block 3 and the back block 3a vertically move up and down between the lower end position a of the solid line and the upper end position b of the chain line, and the The fulcrum of the lever 10 swings back and forth between points A and B along a trajectory K of the tip of the swing arm 12. Point A indicates the position of the fulcrum pin 13 at the lower end of the lifting stroke, and point B indicates the position of the fulcrum pin 13 at the upper end of the lifting stroke. A straight line P extending upward to the right passing through points B and b indicates the position of the swing lever 10 at the upper end of the lifting stroke.

When the sliding block 15 (see FIG. 1) is moved by turning the adjusting screw 16, the pin 20 connecting the sliding block 15 and the connecting rod 7 is
It moves along arc G in FIG. 2 at the lower end of the lifting stroke. Then, the sliding block 15
If the position of is fixed at point c, the fulcrum pin 13 of the swinging lever 10 moves to point C, and the straight line Q connecting points C and c, that is, the center line of the swinging lever 10, moves to the point a above. passing through almost the same location as
Therefore, the height of the sliding block 15 and the height of the needle rest 1 are almost equal to the initial height, but at the upper end of the lifting stroke, the connecting pin 20 at the upper end of the connecting rod 7 rises to point d, and at the same time swings. Lever 1
The fulcrum pin 13 of 0 moves to point D, and the swing lever 1
0 moves on the straight line R connecting points D and d, the position of the sliding block 15 is between points a and b.
A vertical line connecting the point d and an inclined straight line R connecting the point D
, and only the upper end position of the vertical stroke changes significantly. In the figure, m is the amount of change in this upper end position.

In the embodiment shown in FIG. 3, instead of attaching the fulcrum pin 13 of the swing lever 10 to the tip of the swing arm 12, a slot guide 21 is provided in the frame in a direction slightly inclined with respect to the horizontal line in the front-rear direction. The sliding lever 10 is connected to a sliding block 22 that fits into a slot guide 21 by an intersection pin 13, and compared to the embodiment shown in FIG. oscillate.

In the embodiment shown in FIG. 4, the upper end of the connecting rod 7 is connected to the sliding block 15 of the swinging lever 10, and a pin plate 19 fixed to the back side of the paper in the center of the swinging lever 10 is moved up and down integrally with the needle rest 1. Pin 2 in the width direction to block 3
It is connected by 5. In addition, the fulcrum pin 13
may be connected either to the upper end of the swing arm 12 in FIG. 1 or to the sliding block 22 in FIG. 3.

(Effects of the Invention) This invention provides a swinging lever, one end of which is supported so as to swing back and forth, between the needle rest and the upper end of the connecting rod, and the longitudinal position of this swinging lever can be set arbitrarily. A sliding block is attached, and one of the connecting rod and needle rest is connected to this swinging lever, and the other of the connecting rod and needle rest is connected to the sliding block. By adjusting the fixed position of the sliding block, the magnitude of the lifting stroke can be increased or decreased without changing the lower end position of the lifting stroke, and only the upper end position of the lifting stroke can be changed. Moreover, the above-mentioned swing lever is interposed between the needle rest and the upper end of the connecting rod, and a sliding block is attached to this swing lever to transmit the vertical movement of the above-mentioned joining rod to the needle rest. Conventional lifting means such as cranks and cams can be used as is.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an embodiment of the present invention, Fig. 2 is a side view explaining the operation of the embodiment of Fig. 1, Fig. 3 is a side view of main parts of another embodiment, and Fig. 4 is It is a side view of the main part of still another Example. 1...needle rest, 2...sewing machine needle, 3...lifting block, 4...vertical guide, 6...crank, 7...connection rod, 10...swing lever, 1
3...Fully point that can freely swing back and forth, 14...Slot hole, 15
...Sliding block, 16...Adjustment screw, 18...
Lock nut, 19...Pin plate fixed to the swing lever, 20, 25...Connection pin.

Claims (1)

[Claims] 1 A number of sewing machine needles are fixed downward, and a widthwise long needle stand that can be raised and lowered along a vertical guide is raised and lowered via a pair of left and right connecting rods that are driven up and down, In the multi-needle sewing device, which performs multiple rows of single chain stitches using the sewing machine needle on a workpiece that is fed in the front-rear direction, there is provided a needle between the end of the needle rest and the upper end of the connecting rod.
A swinging lever that has a fulcrum that can swing back and forth and can swing up and down is interposed, and a sliding block that can be fixed at any position along its length is attached to this swinging lever. The upper end of the connecting rod is rotatably connected to one of the lever and the sliding block, and the end of the needle rest is rotatably connected to the other of the swinging lever and the sliding block by a connecting pin in the width direction. Multi-needle sewing device.