JPH0659355B2 - Middle presser device for sewing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermediate presser device for preventing the cloth from fluttering as the needle rises when sewing with a sewing machine.

[Conventional technology]

In the case of a sewing machine such as a stab sewing machine which does not use feed dogs and carries out sewing while conveying the cloth in the XY directions, in order to prevent the cloth from rising together with the needle due to friction with the needle, it is possible to prevent the cloth from fluttering. An intermediate presser device is provided which presses down around the needle penetration portion of the cloth when the needle is raised.

As a conventional device of this type, there is one as shown in FIG.

In the figure, the needle bar 1 moves up and down according to the rotation of the upper shaft by a known needle bar up-and-down mechanism. Intermediate presser drive arm 2 for needle bar 1
Is fixed and moves up and down together with the needle bar 1. Further, the intermediate presser drive arm 2 is formed with a projection 2a, which is a long hole 3a of the intermediate presser cam 3 rotatably supported by the machine frame.
The intermediate presser cam 3 is vertically inserted around the shaft 4 as the intermediate presser drive arm 2 moves up and down. Further, the intermediate presser cam 3 is formed with an elliptical hole 3b.
On the inner surface of b, the protrusion 5a formed on the intermediate presser link 5 is formed.
Are in contact with. The intermediate presser link 5 is rotatably supported on the machine frame by a shaft 6, and when the intermediate presser cam 3 rotates, the projection 5a moves upward or downward along the inner surface of the hole 3b, resulting in The intermediate presser link 5 swings vertically. The swing of the intermediate presser link 5 is transmitted to the intermediate presser bar 8 through the connecting link 7, and the intermediate presser member 9 provided at the tip end thereof.
Move up and down with. The intermediate presser member 9 is formed with a presser portion 9b having a hole 9a through which the needle 10 is inserted. When the needle 10 is pulled out of the cloth, the presser portion 9b descends to surround the needle penetrating portion of the cloth. To prevent the cloth from rising together with the needle 10.

After the needle 10 is completely removed from the cloth, the pressing member 9
Is raised, it is possible to prevent the pressing member 9 from being caught by the embroidery formed so far in the subsequent cloth conveying operation.

[Problems to be solved by the invention]

However, the conventional intermediate presser device is effective for a device such as an embroidery sewing machine that sewes a cloth placed and fixed on a flat plate by a cloth support member. In the case of sewing a cloth having elasticity to, there is a problem that the cloth may move up and down as the intermediate presser member 9 moves up and down, resulting in defective seams. That is,
When the cloth is lifted as the intermediate presser member 9 is lifted, the needle thread loop is also lifted accordingly, so that the hook tip of the hook does not catch on the loop, so that a so-called stitch skip occurs. Occurs. Therefore, in the case of such a cloth having elasticity in the vertical direction, it is desirable that the lower presser is not moved up and down, and that the sewing is performed while the intermediate presser member 9 is in the lowered state.

However, in the above-mentioned conventional intermediate presser device, the vertical movement of the needle bar 1 is always transmitted to the intermediate presser bar 8 via the intermediate presser cam 3, the intermediate presser link 5 and the connecting link 7.
It was not possible to perform the sewing operation with the intermediate presser member 9 lowered.

The present invention has been made in view of the above problems, and it is possible to perform the sewing operation while raising and lowering the intermediate presser member, and to perform the sewing operation while maintaining the lowered state of the intermediate presser member. An object of the present invention is to provide a middle presser device for a sewing machine.

[Means for solving problems]

This invention provides a swing mechanism that swings a swing shaft and a swing member provided on the swing shaft as the upper shaft rotates, and rotates one end of the swing member and the other end of the swing member to an intermediate presser member. A rotating member provided so as to be movably connected is provided, and an arm body rotatably supported by a machine frame is rotatably connected to an intermediate portion of the rotating member, and a predetermined direction of the arm body is provided. It is provided with a stopper that restricts the rotation to the.

[Work]

In the present invention, when the sewing operation is performed while moving the intermediate presser member up and down, the mounting position of the swing member or the swing mechanism with respect to the swing shaft is adjusted, and the arm body is brought into contact with the stopper in the intermediate press member descending state. . As a result, when the upper shaft rotates, the pivoting member pivots around the connection point with the arm due to the pivotal movement of the pivoting member, which causes the interlocking member to move up and down and the intermediate presser bar to move. Move it up and down.

Further, when performing the sewing operation with the intermediate presser member fixed downward, the mounting position of the swing member or the swing mechanism is adjusted so that the arm body and the stopper are separated when the intermediate presser member is in the lowered state. When the upper shaft rotates and the swinging member swings in this state, the rotating member rotates about the connecting point with the connecting member, so that the connecting member does not move up and down and the pressing member is maintained in the lowered state. It

Example of Invention

An embodiment of the present invention will be described below with reference to FIGS. In each figure, the same or corresponding parts as those of the conventional example are designated by the same reference numerals, and the detailed description thereof will be omitted.

In the figure, 11 is an upper shaft that is rotated by a drive device (not shown), 12 is a counterweight that rotates together with the upper shaft 11, and 13 is the conversion of the rotational movement of the counterweight 12 into vertical movement of the needle bar 1. It is a needle bar crank. Further, 14 is an eccentric cam fixed to the upper shaft 11, 15 is a swing rod having one end rotatably fitted to the outer periphery of the eccentric cam 14, and 16 is bearing members 17, 18 attached to the machine frame. The swing shaft is inserted and supported in the inside.

Reference numeral 19 denotes a connecting swing arm fastened to the other end of the swing shaft 16 with a screw 19b, and has an arc-shaped elongated hole 1 in the longitudinal direction thereof.
9a is formed, and a shaft portion of a step screw 15a fixed to one end portion of the swing rod 15 is rotatably inserted into the long hole 19a. In addition, above 14, 15, 19
The rocking mechanism A is configured by. Further, 20 is a swing link having one end fixed to the other end of the swing shaft 16, 21
Is a connecting link rotatably connected to the other end of the swing link 20, and the connecting link 21 and the swing link 2
0 and 0 constitute a swing member. Reference numeral 22 denotes an L-shaped rotating member whose one end is rotatably connected to the connecting link 21.
Reference numeral 3 denotes an arm body having a central portion rotatably attached to the machine frame, and one end thereof is rotatably connected to the bent portion of the rotating member 22.

Reference numeral 24 is a stopper that restricts the counterclockwise rotation of the arm 23, and is fixed to the machine frame.

Reference numeral 25 denotes a connecting member having one end rotatably connected to a knuckle 27 provided on the intermediate presser bar 26 and the other end rotatably connected to the rotating member 22. The intermediate presser member 9 constitutes an intermediate presser mechanism together with the intermediate presser bar 26 and the knuckle 27. Reference numeral 28 denotes an intermediate presser adjusting screw, which is screwed into a nut 29 fixed to the machine frame. By rotating this screw 28, the spring 30 expands and contracts along the guide rod 31, and the intermediate presser rod 26 The pressing force is changing.

Next, the operation will be described based on the above configuration. When performing the sewing operation while vertically moving the intermediate presser member 9 such as stab stitching, the stopper 24 and the arm body 23 are always operated during the sewing operation.
Set so that and come into contact. To this end, first, the intermediate presser member 9 is lowered, and the screw 19b of the connecting swing arm 19 is loosened to move the swing shaft 16 and the swing link 20 from the position shown in FIG. 4 to the position shown in FIG. The rotation member 22 is rotated via the connecting ring 21. At this time, the rotating member 22 rotates about the connection point P2 of the connecting member 25 until the arm 23 and the stopper 24 come into contact with each other. The setting work is completed by tightening the screw 19b with the arm 23 and the stopper 24 in contact with each other and fixing the swing shaft 16.

When the sewing operation is started in the above setting state, the eccentric cam 14 rotates in accordance with the rotation of the upper shaft 11, the swing rod 15 swings in the direction of the arrow a, and swings via the connecting swing arm 19. The moving shaft 16 rotates and swings by a predetermined angle. The swing link 20 swings by the swing swing of the swing shaft 16, and the swing is transmitted to the swing member 22 via the connecting link 21. At this time, since the arm 23 connected to the rotating member 22 is in contact with the stopper 24, the rotating member 22 rotates about the connection point P1 with the arm 23, and the connecting member 25 is used. The intermediate presser bar 26 moves up and down. As a result, the pressing member 9 also moves up and down with respect to the needle 10 that moves up and down, which is well-known as the upper shaft 11 rotates, and when the needle 10 is pulled out of the cloth, presses around the needle penetration portion of the cloth. You can suppress flapping.
Further, since the pressing member 9 rises when the cloth is fed, the pressing member 9 does not get caught on the piercing stitches (seam) formed up to that time.

When sewing a cloth that has upward elasticity such as a band,
The above setting state is changed to the setting state as shown in FIG. That is, the arm body 23 is set to be separated from the stopper 24 until the intermediate presser bar 26 reaches the highest position from the lowest position. To do this, loosen the screw 19b while the intermediate presser bar 26 has reached the lowest position, and
The swinging link 20 is further rotated counterclockwise from the set position shown in the figure to a position (α + β) where the arm 23 and the stopper 24 do not come into contact with each other until at least the intermediate presser bar 26 reaches the maximum raised position. The swing arm 20 is fixed.

When the sewing operation is started in this state, as the upper shaft 11 rotates, the rocking rod 15 rocks and the rocking shaft 16 rocks in the same manner as described above. Link 21
However, since the arm member 23 connected to the rotating member 22 is not in contact with the stopper 24, the connecting point P1 which is the above-described rotating fulcrum is movable. In this state, the rotating member 22 rotates about the connecting point P2 with the connecting member 25.

Therefore, even if the rotating member 22 rotates, the rotational force does not act on the connecting member 25, and the intermediate presser bar 26 does not move at all. That is, the sewing operation is performed while the intermediate presser bar 26 is kept in the lowered state. As a result, the cloth is always pressed downward and sewn, so the upper thread loop is always held in the proper position, so the upper thread loop can always be held in the proper position, and the seam can be reliably formed. You can

Further, in this embodiment, by changing the connecting position of the swing rod 15 to the connecting swing arm 19 along the elongated hole 19a, the lifting stroke of the intermediate presser bar 26 can be changed.

In the embodiment, the mounting positions of the swing shaft 16 and the connecting swing arm 19 constituting the swing mechanism A are changed by the screw 19b, but the swing shaft 16 and the swing arm 20 (the swing member is configured). The mounting position of may be changed by a screw.

〔The invention's effect〕

As described above, according to the present invention, the sewing operation can be performed while moving the intermediate presser member up and down, and
Since it is possible to perform the sewing operation while maintaining the state where the intermediate presser member is lowered, it is possible not only to prevent the flat cloth from fluttering such as embroidery sewing, but also to have upward elasticity such as a brim. There is an effect that a stable seam formation can be realized even for cloth.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is an exploded perspective view of what is shown in FIG. 1, and FIGS. 3 and 4 are schematic explanatory views of main parts of what is shown in FIG. 3 shows the initial setting state when the intermediate presser member is raised and lowered, and FIG. 4 shows the initial set state when the intermediate presser member is fixed downward. FIG. 5 is a perspective view showing a conventional intermediate presser device. 9 ... Intermediate presser member 11 ... Upper shaft 20 ... Oscillating arm (oscillating member) 21 ... Oscillating link (oscillating member) 22 ... Rotating member 23 ... Arm 24 ... Stopper

Claims (1)

[Claims] 1. An intermediate presser member that is supported so as to be able to move up and down along a sewing needle and presses the periphery of the needle penetration portion of the cloth when descending, a swing shaft that is rotatably supported by a machine frame, and this swing shaft. And an upper shaft, and a connecting swing arm that swings the swing shaft with the rotation of the upper shaft and a swing rod, and a swing link that is provided on the swing shaft and swings together with the swing shaft. And a connecting link whose one end is rotatably supported by the swinging link and one end which is rotatably connected to the connecting link and whose other end is rotatably connected to the intermediate presser member. A rotatably supported rotative member, an intermediate body rotatably supported by the machine frame, and one end rotatably connected to the intermediate portion of the rotative member, and the arm body And a stopper that restricts rotation of the arm body in a predetermined direction, and is connected to the swing shaft. It is possible to change the contact / separation state of the stopper and the arm body when the intermediate presser member descends by changing the mounting position of, and in the contact state of the stopper and the arm body, the rotating member is connected to the arm body. An intermediate presser for a sewing machine, wherein the connecting point is fixed and the connecting point between the rotating member and the arm is movable when the stopper and the arm are not in contact with each other.