JPH0412790A - Walking bar device of sewing machine - Google Patents

Abstract

PURPOSE:To allow the walking bar teeth to ascend by small force by providing a rotary motion giving means for giving a rotary motion to a walking bar supporting arm, and moving a supporting part to the upper part against energizing force of an anergizing means. CONSTITUTION:Walking bar teeth 2 execute a reciprocating motion in the vertical direction and the horizontal direction, that is, a four-motion feed in connection with a vertical reciprocating motion of a sewing needle 23, and the walking bar teeth 2 transfer working cloth placed on the working cloth placing surface of a needle plate 48. A guide 45 is attached to a transfer lever 39 in about the center position of a supporting part 43 and a connecting part 40, therefore, the stroke amount by which the connecting part 40 moves in order to drive the guide 45 in the vertical direction is large. However, a load required for the connecting part 40 for allowing the guide 45 to ascend against energizing force of an energizing means 49 can be made small. In such a way, a vertical driving mechanism 5 can drive the guide 45 in the vertical direction by small force.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an upper feed device for a sewing machine that applies a feeding motion to a work cloth from above the work cloth.

[Conventional technology] An example of a conventional upper feed device of a sewing machine is shown in FIG.

The upper feed device of the sewing machine includes an upper feed support arm 101 that is rotatably supported. This upper feed support arm 101 rotatably supports an L-shaped transmission lever 103 by a support portion 102 on the free end side. One free end of the transmission lever 103 extends downward from the support portion 102, and this one free end side is driven in the horizontal direction by the vertical drive body 104.

Further, the other free end of the transmission lever 103 is connected to the support portion 10.
2 and extends horizontally from the guide 10 at its free end side.
5 is supported. That is, by driving one free end of the transmission lever 1.3 in the horizontal direction by the vertical drive member 104, the guide 105 supported on the other free end of the transmission lever 103 performs reciprocating motion in the vertical direction. conduct.

The guide 105 described above is a member that supports an upper feed table (not shown) that provides horizontal reciprocating motion to an upper feed dog (not shown) so as to be movable in the horizontal direction.

On the other hand, the guide 105 is directly urged toward the workpiece cloth by the urging means 10 and the like in order to press the upper feed dog toward the workpiece cloth via the upper feed table.

Further, the upper feed support arm 101 is connected to rotational motion imparting means (not shown) for moving the support portion 102 upward against the urging force of the urging means 106 and raising the upper feed dog. . An example of rotational motion imparting means is shown. The rotational motion imparting means is an actuator controlled by a control device, or is composed of a foot pedal operated by the operator and a presser foot lifting lever linked to the foot pedal. It is operated when

[Problems to be Solved by the Invention] The support portion 102 of the upper feed support arm 101 is
In order to raise it against the urging force of , it is necessary for the rotational motion imparting means to apply a force larger than the load applied to the support part 102 to the upper feed support arm 101 . However, the conventional support section 102 receives the biasing force of the biasing means 106 via the horizontally extending transmission lever 103. For this reason,
Conventional rotational motion imparting means needed to generate a large force in order to raise the support portion 102. In other words, the conventional upper feed device of a sewing machine requires a large force when raising the upper feed dog.

Specifically, if a foot pedal is used as the rotary motion imparting means, conventionally it has been necessary to press the foot pedal with great force in order to raise the support section.

The present invention has been made in view of the above circumstances, and its object is to provide an upper feed device for a sewing machine that can raise the upper feed dog by one level with a small force.

a guide that is provided on the transmission lever between the connecting portion and supports the upper feed table so as to be movable in the horizontal direction; a biasing means that biases the guide directly toward the workpiece cloth; A technical means is adopted comprising a rotational motion imparting means for imparting a rotational motion to the support arm and moving the support part upward against the biasing force of the biasing means.

[Means for Solving the Problems] In order to achieve the above object, the upper feed device of the sewing machine of the present invention includes a horizontal drive body that performs horizontal reciprocating motion in accordance with the vertical and reciprocating motion of the sewing needle, and this horizontal drive body. an upper feed table rotatably connected to the upper feed table and having upper feed teeth fixed thereon for transferring the work cloth placed on the work cloth placement surface; and an upper feed support arm rotatably supported; A transmission lever is rotatably supported by a support section on the free end side of the upper feed support arm, and the transmission lever is connected to the free end side of the upper feed support arm via a connecting section, and the connecting section is connected to the up and down reciprocating movement of the sewing needle. A vertical drive body that reciprocates vertically along with the above-mentioned support section and the front [operation] function during sewing.

During sewing, as the sewing needle reciprocates up and down, the vertical drive body reciprocates the free end side of the transmission lever in the up and down direction via the connecting portion. Then, the transmission lever performs a reciprocating rotational movement within a predetermined angle around the support part, and a guide provided on the transmission lever between the support part and the connection part performs a reciprocating movement in the vertical direction.

As a result, the upper feed base supported by the guide reciprocates in the vertical direction, and the upper feed dog reciprocates in the vertical and horizontal directions as the sewing needle reciprocates in the vertical direction.

Since the guide is provided on the transmission lever between the support part and the connecting part, the stroke amount that the connecting part moves to drive the guide in the vertical direction becomes large. However, the load required by the connecting portion to raise the guide against the biasing force of the biasing means can be reduced. In other words, the guide can be driven in the vertical direction with a small force.

Action when raising the upper feed dog.

When an operator raises the upper feed dog, such as when exchanging a workpiece cloth, the rotational motion imparting means applies a rotational motion to the upper feed support arm to raise the support portion. At this time, the transmission lever rotates around the connection part, and a guide provided on the transmission lever between the support part and the connection part is lifted upward. As a result, the upper feed base rises and the upper feed dog rises.

Since the guide is provided on the transmission lever between the support part and the connecting part, the stroke amount that the support part moves to move the guide upward becomes large, but conversely, the guide is biased by the biasing means. The load required to move it upward against the urging force of can be reduced. In other words, the guide can be raised with a small force.

[Effects of the Invention] As explained above, during sewing, the guide can be driven in the vertical direction with a small force, so it is possible to give the upper feed dog reciprocating motion in the vertical direction with a small force. can.

In addition, when raising the upper feed dog, the guide can be raised with a small force, compared to conventional methods.
The upper feed dog can be raised with a small amount of force.

[Embodiment] Next, an upper feed device for a sewing machine according to the present invention will be described based on an embodiment shown in the drawings.

(Configuration of the embodiment) Figures 1 to 5 show embodiments of the present invention.
FIG. 1 is a side view of the main part of the upper feed device of the sewing machine, and FIGS. 2 and 3 are side views showing the link mechanism of the upper feed device of the sewing machine.

b) General explanation of the upper feed device f1 of the sewing machine.

The upper feed device Wt, 1 of the sewing machine includes a horizontal drive mechanism 3 for giving horizontal reciprocating motion to the upper feed dog 2, and an upper feed dog 2.
a horizontal feed momentum adjustment mechanism 4 that adjusts the horizontal momentum of the upper feed dog 2; a vertical drive mechanism 5 that gives the upper feed dog 2 vertical reciprocating motion; and a vertical feed mechanism that adjusts the vertical momentum of the upper feed dog 2. A momentum adjustment mechanism 6 is provided.

The upper feed device 1 of the sewing machine also includes a presser foot 7 shown in FIG.
"Upper feed dog that raises upper feed dog 2 when raising the upper feed dog."
- Equipped with a lifting mechanism 8.

Mouth) Explanation of the horizontal drive mechanism 3.

An eccentric wheel 10 is fixed to a drive shaft 9 that rotates in one direction, and a swing motion is transmitted to a horizontal feed shaft 13 via a feed rod 11 and a horizontal feed arm 12. A horizontal feed adjustment arm 16 is fixed to the end of the horizontal feed shaft 13, in which a square piece 15 is fitted into an arm 14 having a U-shaped cross section. For square piece 15,
One end of the horizontal feed link 17 is fitted. The other end of the horizontal feed link 17 is connected by a pin 20 to a horizontal crankshaft arm 19 fixed to the horizontal crankshaft 18, and transmits the swinging movement of the horizontal feed adjustment arm 16 to the horizontal crankshaft 18. There is. The end of the horizontal crankshaft 18 is provided with a horizontal drive body 21 extending downward, and the horizontal drive body 21
The tip is rotatably connected to one end of the upper feed table 22. As a result, horizontal reciprocating motion is transmitted to the upper feed table 22 along with the vertical reciprocating motion of the sewing needle 23.

C) Description of the horizontal feed momentum adjuster 1114.

One end of the horizontal feed link 17 of the horizontal drive mechanism 3 (square piece 15
One end of the horizontal feed adjustment link 24 is fitted into the side). The other end of this horizontal feed adjustment link 24 is connected to one end of a first horizontal feed adjustment lever 25. This first
The other end of the horizontal feed adjustment lever 25 is fixed to one end of a second horizontal feed adjustment lever 27 via a rotatably supported pin 26. The other end of the second horizontal feed adjustment lever 27 protrudes from the outside of a frame 29 that houses each internal mechanism, and a horizontal feed scale plate 30 is fixed to the frame 29.
is fixed by a thumbscrew 31.

As a result, by loosening the thumbscrew 31 and moving the other end of the second horizontal feed adjustment lever 27 on the horizontal feed scale plate 30, the square piece 15 moves along 71114, and By changing the length of the upper feed shaft with respect to the axis, the amount of horizontal reciprocating motion transmitted to the upper feed table 22 is adjusted.

2) Description of the vertical drive mechanism 5.

The upper knife shaft 32 performs a rocking motion in conjunction with the drive shaft 9
A vertical feed adjustment arm 35, in which a square piece 34 is fitted into an arm 33 having a U-shaped cross section, is fixed to the end of the arm. One end of the vertical feed link 36 is fitted into the square piece 34. The other end of the vertical feed link 36 is connected by a pin to a vertical crankshaft arm 38a fixed to the vertical crankshaft 37, and transmits the swinging motion of the vertical feed adjustment arm 35 to the vertical crankshaft 37. . At the ends of the upper and lower crankshafts 37,
It is provided with a vertical drive body 38 extending in the horizontal direction. On the free end side of this vertical drive body 38, there is a square piece 4 that transmits reciprocating motion in the vertical direction to a connecting portion 40 on the free end side of the three transmission levers.
1 is inserted.

As a result, as the sewing needle 23 reciprocates up and down, the connecting portion 40 of the transmission lever 39 reciprocates in the up and down direction.

The transmission lever 39 is rotatably supported by a support portion 43 on the free end side of an upper feed support arm 42, which will be described later.

Further, the connecting portion 40 on the free end side of the transmission lever 39 is provided in a bifurcated shape, and is connected to a square piece 41 inside the bifurcated portion. The transmission lever 39 has a hole 44 approximately in the center between the support portion 43 and the connection portion 40, and a guide 4 is provided in the hole 44.
5 is inserted. That is, in the transmission lever 39, the guide 45 is rotatably provided between the support part 43 and the connection part 40. The guide 45 includes a groove 46 having a U-shaped cross section. The center portion of the upper feed table 22 is fitted into this 71146, and supports the upper feed table 22 so as to be slidable in the horizontal direction. The guide 45 transmits vertical reciprocating motion to the upper feed table 22 in accordance with the vertical reciprocating motion of the sewing needle 23.

The upper feed dog 2 is fixed to the tip of the upper feed table 22 with a screw 47. The upper feed dog 2 performs an elliptical feed movement (so-called four-movement feed) by combining the horizontal and vertical reciprocating motions transmitted by the horizontal drive mechanism 3 and the vertical drive mechanism 5, and performs a lower feed (not shown). Working together with the teeth, the work cloth placed on the work cloth placement surface of the throat plate 48 is transferred.

On the other hand, the guide 45 is directly urged toward the work cloth by the urging means 49. This urging means 49 will be specifically explained. The urging means 49 includes a presser bar 50 placed on the upper side of the guide 45, a presser adjustment screw 51 for adjusting the urging force, and a compression coil spring 52 disposed between the presser rod 50 and the presser adjustment screw 51. It consists of The urging force of the urging means 49 is set to be large so that the upper feed dog 2 follows the movement of the vertical drive mechanism 5 when the upper feed f12 is operated at high speed.

On the other hand, the upper feed support arm 42 is rotatably supported around the upper feed support shaft 54 via a metal 53. This upper feed support arm 42 is provided with a stopper 55 that extends to one side, and when this stopper 55 comes into contact with the frame 29, the position of the lower end of the support portion 43 of the upper feed support arm 42 is regulated.

e) Description of the vertical feed momentum adjustment mechanism 6.

One end of the vertical feed link 36 of the vertical drive mechanism 5 (square piece 34
One end of the vertical feed adjustment link 56 is fitted into the vertical feed adjustment link 56 (side). The other end of this vertical feed adjustment link 56 is connected to one end of a first vertical feed adjustment lever 57. This first
The other end of the vertical feed adjustment lever 57 is fixed to one end of a second vertical feed adjustment lever 59 via a rotatable pin 58. The other end of the second vertical feed adjustment lever 59 protrudes from the outside of the frame 29 and is fixed to a vertical feed scale plate (not shown) fixed to the frame 29 with a thumbscrew 60.

As a result, by loosening the thumbscrew 60 and moving the other end of the second vertical feed adjustment lever 59 on the vertical feed scale plate, the square piece 34 moves along the stream 33.
4 and the axis of the upper knife shaft 32 change, and the guide 45
The amount of reciprocating motion in the vertical direction transmitted to is adjusted.

5) Upper feed dog"-elevator [8 will be explained using FIGS. 4 and 5.

The upper feed dog upper valve mechanism 8 is a rotational movement applying means of the present invention that applies a rotational movement to the upper feed support arm 42 and moves the support part 43 upward against the urging force of the urging means 49. A lifting intermediate lever 61 is provided.

This presser foot lifting intermediate lever 61 has an abbreviated shape, and the bent portion is connected to the upper feed support shaft 5 through a metal (not shown).
It is rotatably supported around 4.

One free end of the presser foot lifting intermediate lever 61 extends upward and faces the adjustment screw 62 screwed into the stopper 55 of the upper feed support arm 42 with a certain gap therebetween. Further, a collar 6 fixed to the upper feed support shaft 54 is provided on the free end side extending upward of the presser foot lifting intermediate lever 61.
The protrusions 64 of No. 3 also face each other with a certain gap therebetween. The other free end of the intermediate presser foot lifting lever 61 extends in the horizontal direction and is connected to a foot pedal (not shown) via a transmission mechanism (not shown). By adjusting the above two gaps, the upper feed dog 2 and the presser foot 7 can be adjusted.
You can adjust the amount and timing of the rise.

Note that a presser arm 65 is fixed to the end of the upper feed support shaft 54. A cloth presser foot 7 is fixed to the free end side of the presser arm 65 by screws, and presses the workpiece cloth toward the throat plate 48 from above. Note that the free end side of the presser arm 65 is urged downward by an urging means 66.

As a result, when the operator steps on the foot pedal, the presser foot lifting intermediate lever 61 rotates via the transmission mechanism, and the upper feed support arm 42 and upper feed support shaft 54 rotate, causing the upper feed dog 2 and the cloth The presser foot 7 also rises.

(Operation of the embodiment) Next, the operation of the embodiment of the portion according to the present invention will be briefly described.

g) Operation during sewing.

During sewing, as the sewing needle 23 reciprocates up and down, the horizontal drive body 21 of the horizontal drive mechanism 3 reciprocates the upper feed table 22 in the horizontal direction, and the vertical drive body 3 of the vertical drive mechanism 5
8 causes the guide 45 to reciprocate in the vertical direction. Then, the upper feed dog 2 performs a reciprocating movement in the vertical and horizontal directions, that is, four-movement feed, in accordance with the vertical reciprocating movement of the sewing needle 23, and the upper feed dog 2 is placed on the work cloth placement surface of the throat plate 48. Transfer the placed work cloth.

Since the guide 45 is attached to the transmission lever 39 at a position approximately in the center between the support part 43 and the connecting part 40, the stroke amount that the connecting part 40 moves to drive the guide 45 in the vertical direction is large. However, the connecting portion 40 is connected to the guide 45.
It is possible to reduce the load required to raise the body against the biasing force of the biasing means 49. That is, the vertical drive machine 115 can drive the guide 45 in the vertical direction with a small force.

H) Operation when raising upper feed dog 2.

When the worker steps on the foot pedal, the presser foot lifting intermediate lever 6
1 rotates, and the rotational movement of the presser foot lifting intermediate lever 61 is transmitted to the upper feed support arm 42 via the adjustment screw 62 and the stopper 55. A load is applied to the foot pedal to raise the support part 43 against the biasing means 49, and a load is applied to the presser foot 7 by the biasing means 6.
When a lifting load is applied against 6, the upper feed support arm 4
2 and the upper feed support shaft 54 rotate.

When the support part 43 rises due to the rotation of the upper feed support arm 42, the transmission lever 39 rotates around the connection part 40,
The guide 45 between the support part 43 and the connecting part 40 is lifted upward. As a result, the upper feed table 22 is raised, the upper feed dog 2 is raised, and the presser foot 7 is raised.

Since the guide 45 is attached to the transmission lever 39 at a position approximately in the center between the support part 43 and the connecting part 40, the stroke amount that the support part 43 moves in the direction between the guide 45 becomes large. . However, the load required to move the guide 45 upward against the urging force of the urging means 49 can be reduced. In other words, the load required to press the foot pedal to raise the upper feed dog 2 can be reduced.

(Effects of Example) As shown in the above example, during sewing, the guide 45 can be driven in the vertical direction with a small force.
The lower drive mechanism 5 can be driven by an electric motor with a smaller output torque than the conventional one. As a result, the sewing machine can be made smaller and lighter, and the manufacturing cost of the sewing machine can be kept low. In addition, since the load required by the vertical drive body 38 to drive the connecting portion 40 in the vertical direction is reduced, the vertical drive unit $15
The load on each part is also reduced. As a result, the durability of each part of the vertical drive mechanism 5 is improved, and the durability of the sewing machine is improved.

On the other hand, when raising the upper feed dog 2, the upper feed dog 2 can be raised via the guide 45 with a small stepping force, so the labor of the operator can be reduced.
As a result, the fatigue of the worker who operates the sewing machine can be reduced.

(Modifications) The present invention can be modified in various ways without departing from the scope of the invention, examples of which are listed below.

Although an example has been shown in which the guide 45 is attached to the transmission lever 39 at a position approximately in the center between the support part 43 and the connection part 40,
3 and the connecting part 40, the transmission lever 39 may be shifted toward the supporting part 43 side or the connecting part 40 side. The load can be reduced, and by shifting it toward the connecting portion 40, the load when raising the upper feed dog 2 can be reduced.

That is, depending on the position of the guide 45, the load on the vertical drive mechanism 5 and the load when raising the upper feed dog 2 can be adjusted.

Although an example has been shown in which the upper feed dog 82 is raised by the force of the operator, the upper feed dog 2 may be raised by force generated by an actuator controlled by a control device.

[Brief explanation of drawings]

Figures 1 to 5 show embodiments of the present invention. Figure 1 is a side view of the main part of the upper feed device of the sewing machine, and Figures 2 and 3 are the link mechanism of the upper feed device of the sewing machine. FIG. 4 is a side view of the upper feed dog raising mechanism, and FIG. 5 is a rear view of the upper feed dog raising mechanism. FIG. 6 is a side view of a main part of an upper feed device of a sewing machine for explaining the prior art. In the diagram: 1... Upper feed device of the sewing machine 2... Upper feed dog 8... Upper feed dog upper limit l! l structure (rotational motion imparting means) 21... horizontal drive body 22... upper feed table 23...
・Sewing needle 38...Bow...Lower drive body 39...Transmission lever 40...Connection part 42...Upper feed support arm 43...Support part 45...Guide 48...
・Throat plate 49...biasing means Fig. 5

Claims (1)

[Scope of Claims] 1) (a) A horizontal drive body that performs horizontal reciprocating motion in accordance with the vertical and reciprocating motion of the sewing needle; (b) A workpiece cloth placement surface rotatably connected to the horizontal drive body. (c) a rotatably supported upper feed support arm; and (d) a free end of this upper feed support arm. (e) a transmission lever rotatably supported by a support part on the side; (e) connected to the free end side of the transmission lever via a connecting part, and causing the connecting part to move up and down in a reciprocating manner in accordance with the up and down reciprocating movement of the sewing needle; (f) a guide provided on the transmission lever between the support part and the connection part to support the upper feed table movably in a horizontal direction; (g) process the guide; (h) applying a rotational motion to the upper feed support arm to move the support part upward against the urging force of the urging means; An upper feed device for a sewing machine, comprising means.