JPH03258289A - Cloth feeding device of sewing machine - Google Patents

Abstract

PURPOSE:To simplify a cloth feeding mechanism by a method wherein a throat plate is moved up from and down to a dog teeth by a throat plate moving mechanism, cloths are held between the throat plate and a presser member when the throat plate is moved up, and the dog teeth is brought in feed action when the throat plate is moved down, and in return action when the throat plate is moved up. CONSTITUTION:When a sewing needle is moved up, a controller 44 controls a throat plate up-and-down driving motor 24 to rotate a triangle cam 26 so that a throat plate 18 is moved down and a throat plate face 20 is lowered. A presser member 6 is forced to descend together with the throat plate 18 by the force of a spring 10, and when the throat plate face 20 is lowered below a dog teeth 22, cloths 1 are held between the presser member 6 and the dog teeth 22. A pinion 38 is revolved by the controller 44 to move a horizontal-transfer arm 32 in the direction B, and the dog teeth 22 is moved forward to feed the cloths 1. After that, the triangle cam 26 is turned by the controller 44 to move the throat plate 18 up, and when the throat plate face 20 is raised above the dog teeth 22, the cloths 1 are held between the throat plate 18 and the presser member 6. Then the pinion 38 is turned in the direction C to move the horizontal-transfer arm 32 in the direction D, and the dog teeth 22 is moved back.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cloth feeding device for a sewing machine that feeds cloth to a position where the next stitch is to be formed.

[Prior Art] Conventionally, cloth feeding devices have been known that feed cloth to the next stitch forming position by moving a feeding dog. This involves raising the feed dog above the throat plate and bringing it into contact with the cloth, and moving the cloth forward by a horizontally determined seam bone while pressing the cloth against the presser member. After that, the feed dog is lowered from the throat plate, and the feed dog is horizontally retracted to return to the starting point of movement, so-called four-movement feed in which the feed dog moves vertically and horizontally, which is repeated to feed the cloth. It is.

[Problems to be Solved by the Invention] However, in such conventional cloth feeding devices, generally, the feed table that holds the feed dog is rotated by an eccentric cam for horizontal feeding via a swinging arm for horizontal feeding. Horizontal feed/
A horizontal movement mechanism that provides return movement and a vertical movement mechanism that provides vertical movement to the feed table via a swing arm for vertical feed by rotation of an eccentric cam for vertical feed are required. In this way, the two moving mechanisms are linked to the feed dog, and the feed dog performs four-movement feeding, which is a compound vertical and horizontal movement, resulting in a complicated mechanism.The present invention therefore solves the above-mentioned problems. The purpose of this invention is to provide a cloth feeding device with a simple mechanism.

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following configuration as a means for solving the problems. That is, the present invention has the following configuration as a means for solving the problems. A needle plate moving mechanism that lowers and raises the needle plate from the feed dog, pinches the cloth with the presser member when the needle moves upward, moves the feed dog forward when it descends, and moves the feed dog back when it rises. This is the structure of a cloth feeding device for a sewing machine, which is characterized in that a mechanism feeds the cloth while sandwiching it between the presser member and the feed dog when the cloth is lowered.

[Function] The cloth feeding device of the sewing machine of the present invention having the above configuration (the companion throat plate moving mechanism lowers the throat plate from the feed dog, and at the time of the descent, the feed dog moving mechanism feeds and moves the feed dog to direct the needle plate toward the fabric) The fabric is sandwiched between the presser member and the feed dog, which are biased by the force, and then fed.Then, the throat plate moving mechanism raises the throat plate above the feed dog to sandwich the fabric between the presser member and the throat plate, and as it rises, the feed dog A moving mechanism moves the feed dog back.

[Example] Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a schematic diagram of a cloth feeding device of a sewing machine according to an embodiment of the present invention. A presser member 6 is attached to the lower end of the presser bar 4, which is supported by the sewing machine arm 2 in a vertically movable manner, with a mounting screw 8, and a presser bar holder is located in the middle of the presser bar 4.
4 is screwed on. A presser spring 10 is compressed and inserted between the presser bar holder 4 and the sewing machine arm 2 to urge the presser member 6 toward the cloth via the presser bar 4. Furthermore, by operating a presser foot lifting lever (not shown), the presser bar 4 and the presser member 6 are raised via the presser bar holder 14, and are held in the raised position.

A throat plate 18 on which the cloth 1 is placed is arranged, and the throat plate 18
The upper throat plate surface 20 is a smooth flat surface so that the cloth can easily pass through it during cloth feeding. In addition, the presser member 6
A feed dog through hole 23 is provided opposite to the feed dog through hole 23, and this feed dog through hole 23 allows the throat plate 18 to move up and down without being hindered by a feed dog 22, which will be described later. 2
3, the feed dog 22 is shaped so that it can be moved forward and backward along the throat plate 18. The pressing member 6 and the feed dog 2
2, and the cloth 1 can be held between the presser member 6 and throat plate 8.

A triangular cam 26 is provided on the lower side of the throat plate 8 and is rotated by a throat plate vertical motor 24 fixed to the bottom plate 28. By rotating the triangular cam 26, the throat plate [8] is raised and lowered, and when the throat plate 18 is raised to the maximum, it is brought into contact with the triangular cam 26. As shown in
2, and when the throat plate 18 is lowered to the maximum (as shown in FIG. The assembly plate 18 may be raised and lowered by converting rotation into reciprocating motion using an eccentric cam, an elliptical cam, a crank mechanism, or the like, or by directly causing reciprocating motion using a solenoid or the like.

Further, the feed dog 22 is attached to a horizontally moving arm 32, and a rack portion 34 is formed on this horizontally moving arm 32. This rack portion 34 is engaged with a pinion 38 that is rotated by a feed dog moving motor 36 fixed to the bottom plate 28.

Further, the horizontally moving arm 32 is supported by a support base 40 screwed to the bottom plate 28 so as to be slidable in parallel to the throat plate surface 20. The throat plate up/down motor 24 and the feed dog moving motor 36 are both connected to a control device 44 to lower the throat plate 18 from the feed dog 22, feed and move the feed dog 22 at the time of the descent, and then, Both motors 24 and 36 are controlled so that the throat plate 8 is raised and the feed dog 22 is moved back when the throat plate 8 is raised.

The aforementioned nail plate 18, throat plate up/down motor 24, triangular cam 2
6. The needle plate moving mechanism 30 is configured by the control device 44, and includes a horizontal moving arm 32, a feed plane moving motor 36, and a pinion 38.
, the support table 40 and the feed surface moving mechanism 42 by the control device 44.
It consists of

Next, the operation of the cloth feeding device of the sewing machine of this embodiment will be explained.

When the needle (not shown) rises, the control device 44 controls the needle plate up/down motor 24 to rotate the triangular cam 26, as shown in FIG.
From the state of (a), the throat plate 18 is lowered to lower the throat plate surface 20. Then, the presser member 6 descends together with the throat plate 18 due to the biasing force of the presser spring 0, and the throat plate surface 20 moves toward the feed dog 2.
2, the cloth 1 is sandwiched between the feed member 6 and the feed dog 22 as shown in FIG. Then, the control device 44 controls the feed surface moving motor 36 to rotate the pinion 38 in the direction of arrow A and move the horizontal moving arm 32 in the direction of arrow B, so that the feed surface is moved as shown in FIG. The teeth 22 are fed and moved horizontally by a determined stitch length. The cloth 1 slides while being pressed against the feed dog 22 by the presser member 6, and is fed by the stitch length to the position shown in FIG. 3(c).

Thereafter, the control device 44 controls the throat plate up/down motor 24 to rotate the triangular cam 26 to raise the throat plate 18 from the state shown in FIG. , the throat plate] 8 is in contact with the cloth, and the throat plate] 8 and the presser member 6
The cloth 1 is held between the two.

In this state I, the control device 44 controls the feed surface moving motor 36 to rotate the pinion 38 in the direction of arrow C, which is opposite to the direction of arrow 6, and move the horizontal moving arm 32 in the direction of arrow. As shown in FIG. 3(d), the feed dog 22 is moved back horizontally to the starting point of movement, returning to the state shown in FIG. 3(a). By repeating this, the cloth 1 is fed stitch by stitch. In addition, FIG. 4 shows vertical displacement of the needle, feed dog 22, and throat plate surface 20 of this embodiment during one cycle in which the needle returns from the uppermost position to the uppermost position again on the vertical axis.
It is a time chart showing time on the horizontal axis.

As described above, in the fabric feeding device of the sewing machine of this embodiment, the throat plate 18 is lowered from the feeding teeth 22, the cloth 1 is held between the presser member 6, and the feeding teeth 22 are moved to feed the fabric. After that, raise the throat plate 8 and sandwich the cloth with the presser member 6,
The feed dog 22 is moved back to the starting point of movement. By repeating this, the cloth is sent.

In this way, the feed surface moving mechanism 42 may be a simple mechanism that causes the feed dog 22 to move forward and backward only in the horizontal direction. Further, the throat plate moving mechanism 30 may be a simple mechanism that moves the throat plate 8 downward and upward only in the vertical direction, and the mechanism for feeding the cloth can be simplified.

The present invention is not limited to these embodiments in any way, and may be implemented in various forms without departing from the gist of the present invention. For example (L: Using a crank mechanism etc. that converts the rotation of the Booneau into reciprocating motion, the feed dog 221 is moved forward and back, and the rotation of the same pulley is connected to a cam mechanism etc. that lowers and raises the needle plate 8 using a link mechanism) so that when the throat plate] 8 is lowered than the feed dog 22, the feed dog 22 moves, and when the throat plate 18 is raised above the feed dog 22, the feed dog 22 moves back. , without using the control device 44, it can be similarly implemented with a mechanical structure or with a configuration driven by a single motor.

[Effects of the Invention] As described in detail above, in the fabric feeding device of the sewing machine of the present invention, the throat plate moving mechanism lowers and raises the throat plate, and the feeding surface moving mechanism moves the feed dog to feed and return, thereby feeding the fabric. Since each of the cloth feeders has a simple configuration, it is possible to simplify the cloth feeding mechanism.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a cloth feeding device of a sewing machine according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the present embodiment when the throat plate is raised,
FIG. 3 is an explanatory diagram of movement of the throat plate and feed dog during cloth feeding in this embodiment, and FIG. 4 is a time chart showing displacement of the needle, feed dog, and throat plate surface in this embodiment. ]... Cloth 6... - Pressing member 18... Throat plate 22... Feed dog 30... Throat plate moving mechanism 42... Feed dog moving mechanism

Claims (1)

[Scope of Claims] A presser member biased toward the cloth is provided, and a throat plate moving mechanism that lowers and raises the throat plate from the feed dog pinches the cloth with the presser member when the throat plate is raised, and when the cloth is lowered, The sewing machine is characterized in that the fabric is fed while being sandwiched between the presser member and the feed dog during the descent by a feed dog moving mechanism that feeds the feed dog and moves the feed dog back when the feed dog goes up. Cloth feeding device.