JP2001162076A - Fabric feeding device for sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure optimum, vertical/horizontal momentums of feed gear without preparing several kinds of vertical feed and horizontal feed cams having different eccentric amounts and without changing the combination of cams when such sewing conditions as the kind and thickenss of the fabric to be sewn are changed. SOLUTION: This machine comprises a vertical feed shaft rotating in linkage with rotation of a main shaft, a horizontal feeding rod loosely fitted to an ecccentric cam fixed at its one end to a rear portion of the vertical feed shaft and giving horizontal movement to a feed gear, a vertical feed arm loosely fitted at its lower end to an eccentric cam fixed to a front end of the vertical feed shaft and giving vertical movement to the feed gear. In the machine, at least one of the two eccentric cams is constructed to have a double eccentric cam structure, thereby making the maximum movement of the feed gear variable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cloth feeder for a sewing machine, and more particularly to a cloth feeder in which an elliptical motion is given to a feed dog by giving horizontal and vertical motions to a feed table supporting the feed dog. And a cloth feeding device for a sewing machine.

[0002]

2. Description of the Related Art A conventional cloth feeder for a sewing machine of this type will be described with reference to FIGS. 6, 7, 8 and 9. FIG.

FIG. 6 is a perspective view of a main part of the cloth feeder, FIG. 7 is an exploded perspective view of a horizontal feed rod of FIG. 6, and FIG. 8 is an exploded perspective view of a vertical feed arm of FIG. FIG. 9 is a view taken in the direction of the arrow A in FIG.

A vertical feed shaft 1 is supported by a bearing 2 fixed to a bed of a sewing machine (not shown), and rotates in conjunction with the rotation of a main shaft of the sewing machine (not shown). 6 and 7, a horizontal feed cam 3a having an eccentric cam 3a eccentric with respect to the axis of the vertical feed shaft 1.
Are fixed by screws 4.

A horizontal feed rod 5 has a left end 5a loosely fitted to an eccentric cam 3a of the horizontal feed cam 3 via a bearing 6, and a right end 5b of the horizontal feed rod 5 through a feed adjuster 7 to feed the horizontal feed. It is rotatably connected to a connecting arm 9 fixed to a rear portion 8a of the shaft 8. Reference numeral 10 denotes a thrust receiver for the horizontal feed rod 5, and the horizontal feed cam 3
It is fixed to the end face.

The feed adjusting body 7 has a central shaft 7a rotatably supported by a bed of a sewing machine (not shown) to adjust a feed amount and change a feed direction.

The horizontal feed shaft 8 is supported by a bearing 12 fixed to a bed of a sewing machine (not shown), and reciprocates the horizontal feed rod 5 in the horizontal direction by the eccentric cam 3a of the horizontal feed cam 3 to control the feed. 7 and the connecting arm 9, the horizontal feed shaft 8
This is transmitted as a swinging motion of the horizontal feed arm 13 fixed to the front end 8b of the front end 8b.

A vertical feed cam 14 having an eccentric cam 14a eccentric to the axis of the vertical feed shaft 1 is fixed to a front end 1b of the vertical feed shaft 1 by a screw 15, as shown in FIGS. ing.

Reference numeral 16 denotes an upper and lower feed arm, the lower end 16a of which is loosely fitted to an eccentric cam 14a of the upper and lower feed cam 14 via a bearing 17, and the upper end 16b of the upper and lower feed arm 16 supports a feed dog 18 at the center. A left end 19a of the feed base 19 and a vertical feed base shaft 2 fixed to the vertical feed arm 16 with a screw 20.
1 and are rotatably connected.

The right end 19b of the feed base 19 is connected to a horizontal feed base shaft 22 fixed to the tip 13a of the horizontal feed arm 13.
And are rotatably connected. Reference numeral 23 denotes a thrust receiver for the vertical feed arm 16, and the vertical feed cam 1 is driven by a screw 24.
4 is fixed to the end face.

Next, the operation of the conventional cloth feeder for a sewing machine will be described with reference to FIG. When the sewing machine is driven and its main shaft rotates, the horizontal feed arm 13 swings as described above due to the rotation of the vertical feed shaft 1 linked to the main shaft. The rotation of the vertical feed shaft 1 and the swing of the horizontal feed arm 13 cause the feed dog 1
8 makes an elliptical motion as follows.

That is, the eccentric cam 14a of the vertical feed cam 14
When the vertical feed shaft 1 starts rotating from a state in which the eccentric position of the vertical feed shaft 1 is below the axis of the vertical feed shaft 1 as shown in FIG. The left end 19a is raised, whereby the feed dog 18 is in the raised position.

At the same time, the horizontal feed arm 13 starts oscillating in the counterclockwise direction, and the right end 19b of the feed base 19 is pushed to the left, whereby the feed dog 18 moves to the left, and the upper surface of the feed dog 18 The cloth is fed to the left in cooperation with a cloth presser (not shown) during a period in which the cloth protrudes above the cloth receiving surface on the upper surface of the bed of the sewing machine (not shown). Eventually, the eccentric position of the eccentric cam 14a will be above the axis of the vertical feed shaft 1, and the cloth will be fed further to the left.

Next, when the vertical feed shaft 1 further rotates from the above state, the vertical feed arm 16 starts to descend gradually.
The left end 19a of the feed base 19 descends, and thereby the feed dog 1
8 is in the lowered position, and at the same time, the horizontal feed arm 13 starts swinging clockwise, and the right end 19b of the feed base 19 moves rightward, whereby the feed dog 18 moves rightward to the original position. Returning, the eccentric position of the eccentric cam 14a is the position shown in FIG.
The elliptical movement is completed. That is, the feed dog 18
The cloth is sent by drawing an elliptical motion trajectory as shown in (1).

[0015]

However, in this type of cloth feeder for a sewing machine, the maximum momentum of the vertical and horizontal feed dogs is limited by the vertical feed cam and the horizontal feed cam with respect to the axis of the vertical feed shaft. Since the eccentric amount of the eccentric cam is determined, when sewing conditions such as the type and thickness of the cloth to be sewn change, in order to obtain the optimal vertical and horizontal momentum of the feed dog, several types with different eccentric amounts are required. It was necessary to prepare such vertical feed cams and horizontal feed cams and rearrange them.

The eccentric amount of the eccentric cams of the vertical feed cam and the horizontal feed cam is set to be optimal in accordance with the momentum of the normally used feed dog. As a result, the rotational imbalance increases, and the vibration and noise of the entire sewing machine increase, so that the rotational speed of the main shaft of the sewing machine must be kept low at all times, and there is a problem that the sewing work efficiency is reduced.

[0017]

According to a first aspect of the present invention, there is provided an eccentric cam fixed to a rear portion of the upper and lower feed shafts. A horizontal feed rod, one end of which is loosely fitted to give horizontal movement to the feed dog, and an upper and lower feed arm, whose lower end is loosely fitted to an eccentric cam fixed to the front end of the vertical feed shaft, and gives vertical movement to the feed dog. In the cloth feeding device of the sewing machine provided, at least one of the eccentric cam in which one end of the horizontal feed rod is loosely fitted and the eccentric cam in which the lower end of the upper and lower feed arms are loosely fitted has a double eccentric cam structure, so that the feed dog The maximum momentum was variable.

According to the first aspect of the present invention, since the maximum amount of movement of the feed dog is made variable, there is no need to prepare and reassemble several types of vertical feed cams and horizontal feed cams having different eccentricities.

Also, the rotation speed of the main shaft of the sewing machine may be reduced only when a large amount of momentum of the feed dog is required, and the sewing machine can be driven at a high rotation speed with the normally used momentum of the feed dog, thereby improving sewing work efficiency. There is an excellent effect. According to the invention of claim 2, the maximum vertical movement amount of the feed dog is variable by making the front end of the vertical feed shaft an eccentric shaft and loosely fitting the lower ends of the vertical feed arms to an eccentric cam fixed to the eccentric shaft. did.

According to the second aspect of the present invention, since the maximum vertical movement amount of the feed dog is made variable, there is no need to prepare and reassemble several types of vertical feed cams having different eccentric amounts. The rotation speed of the main shaft of the sewing machine may be reduced only when vertical movement is required, and the sewing machine can be driven at a high rotation speed with the vertical movement of the normally used feed dog, which has an excellent effect of improving sewing work efficiency.

According to a third aspect of the present invention, a vertical eccentric cam shaft having an eccentric cam is fixed to a front end of the vertical feed shaft, and a lower end of the vertical feed arm is loosely fitted to the eccentric cam of the vertical eccentric cam shaft. The maximum vertical momentum of the feed dog was made variable. According to the third aspect of the present invention, the maximum vertical movement amount of the feed dog is made variable, so that there is an excellent effect similar to the second aspect of the invention.

According to a fourth aspect of the present invention, a horizontal eccentric cam shaft having an eccentric cam is fixed to a rear portion of the vertical feed shaft, and one end of a horizontal feed rod is loosely fitted to the eccentric cam of the horizontal eccentric cam shaft. The maximum horizontal momentum of the feed dog was made variable.

According to the fourth aspect of the present invention, since the maximum horizontal movement amount of the feed dog is made variable, there is no need to prepare and reassemble several types of horizontal feed cams having different eccentric amounts. The rotation speed of the main shaft of the sewing machine may be reduced only when a horizontal momentum is required, and the sewing machine can be driven at a high rotation speed with the horizontal momentum of the normally used feed dog, which has an excellent effect of improving sewing work efficiency.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. Note that components having the same configuration and operation as those of the conventional technology are denoted by the same component names and numbers as those of the conventional technology, and description thereof is omitted.

First, a first embodiment will be described with reference to FIGS. FIG. 1 is an exploded perspective view of a vertical feed arm, which is a different part from FIGS. 6 and 8 for explaining the prior art. FIGS. 3A and 3B show only an eccentric cam of the vertical feed arm. FIG.

Reference numeral 101 denotes a vertical feed shaft.
01 is an eccentric shaft 101b that is eccentric with respect to the axis of the vertical feed shaft 101, and the eccentric shaft 101b
Eccentric cam 1 eccentric to the axis of the eccentric shaft 101b
A vertical feed cam 14 having 4 a is fixed by a screw 15.

The first embodiment has the above configuration, and the operation will be described below. As shown in FIG. 3A, the eccentric position of the eccentric shaft 101b (the amount of eccentricity b with respect to the axis of the vertical feed shaft 101) and the eccentric position of the eccentric cam 14a (the eccentric shaft 1).
The vertical eccentric amount a) of the vertical feed shaft 101
When the vertical feed cam 14 is fixed to the eccentric shaft 101b with the screw 15 so as to be above the axis of
The momentum in the up and down direction is 2x (a + b), which is the maximum,
The vertical momentum of the feed dog 18 is maximized.

Further, as shown in FIG.
01b is made horizontal with respect to the axis of the vertical feed shaft 101, and the eccentric position of the eccentric cam 14a is changed to the vertical feed shaft 101.
The vertical feed cam 14 so that it is above the axis of the eccentric shaft 1.
When it is fixed to the screw 01b by the screw 15, the vertical momentum of the vertical feed arm 16 becomes approximately 2 × a, and the vertical momentum of the feed dog 18 becomes almost the same as the conventional normal vertical momentum.

As described above, the maximum vertical movement amount of the feed dog 18 can be freely changed only by changing the fixing direction of the vertical feed cam 14 with respect to the eccentric shaft 101b.

Next, a second embodiment will be described with reference to FIGS. FIG. 2 is an exploded perspective view of a vertical feed arm, which is a different part from FIGS. 6 and 8 for explaining the prior art. FIGS. 3C and 3D show only eccentric cams of the vertical feed arm. FIG.

A vertical eccentric cam shaft 125 having an eccentric cam 125a eccentric to the axis of the vertical feed shaft 1 is fixed to a front end 1b of the vertical feed shaft 1 by a screw 126. A vertical feed cam 114 having an eccentric cam 114 a eccentric to the axis of the eccentric cam 125 a is fixed to the eccentric cam 125 a by a screw 15.

Reference numeral 116 denotes an upper and lower feed arm, and its lower end 116a
Is loosely fitted to the eccentric cam 114a of the vertical feed cam 114 via a bearing 117, and the upper end 116 of the vertical feed arm 116
b is rotatably connected to a left end 19a of a feed bar 19 supporting a feed dog 18 at a central portion thereof, via a vertical feed bar shaft 21 fixed to a vertical feed arm 116 with a screw 20. Reference numeral 123 denotes a thrust receiver of the vertical feed arm 116, which is fixed to an end face of the vertical feed cam 114 by a screw 24.

The second embodiment has the above configuration, and the operation will be described below. As shown in FIG. 3C, the eccentric position of the eccentric cam 125a (the eccentric amount b of the eccentric cam 125a with respect to the axis of the vertical feed shaft 1) and the eccentric position of the eccentric cam 114a (the eccentric cam with respect to the axis of the eccentric cam 125a). 1
When the vertical feed cam 114 is fixed to the eccentric cam 125a by the screw 15 so that the eccentric amount a of the vertical feed shaft 1 is above the axis of the vertical feed shaft 1, the vertical momentum of the vertical feed arm 116 becomes 2 × ( a + b) and the feed dog 18
The vertical momentum becomes maximum.

As shown in FIG. 3D, the eccentric position of the eccentric cam 125a is made horizontal with respect to the axis of the vertical feed shaft 1, and the eccentric position of the eccentric cam 114a is set with respect to the axis of the vertical feed shaft 1. The eccentric cam 1
25a, the upper and lower feed arms 116
The momentum in the vertical direction of the feed dog 18 is approximately 2xa.
Is approximately the same as the conventional normal vertical momentum. Thus, the maximum vertical movement amount of the feed dog 18 can be freely changed only by changing the fixing direction of the vertical feed cam 114 with respect to the eccentric cam 125a.

Further, the third embodiment is described with reference to FIGS.
This will be described below. FIG. 4 is an exploded perspective view of a horizontal feed rod portion which is a different part from FIGS. 6 and 7 for explaining the prior art, and FIGS. 5A and 5B show only the eccentric cam of the horizontal feed rod portion. FIG.

A horizontal eccentric cam shaft 127 having an eccentric cam 127a eccentric to the axis of the vertical feed shaft 1 is fixed to a rear portion 1a of the vertical feed shaft 1 by a screw 128. The horizontal feed cam 103 having the eccentric cam 103a eccentric with respect to the axis of the eccentric cam 127a is fixed to the eccentric cam 127a by the screw 4.

Numeral 105 denotes a horizontal feed rod, and its left end 10
5a is loosely fitted to the eccentric cam 103a of the horizontal feed cam 103 via the bearing 106, and the right end 105b of the horizontal feed rod 105 is connected to the connecting arm 9 fixed to the rear portion 8a of the horizontal feed shaft 8 via the feed adjusting body 7. And are rotatably connected. Reference numeral 110 denotes a thrust receiver of the horizontal feed rod 105, which is fixed to an end face of the horizontal feed cam 103 by a screw 11.

The third embodiment has the above configuration, and the operation will be described below. As shown in FIG. 5A, the eccentric position of the eccentric cam 127a (the eccentric amount d of the eccentric cam 127a with respect to the axis of the vertical feed shaft 1) and the eccentric position of the eccentric cam 103a (the eccentric amount of the eccentric cam 127a with respect to the axis). c)
When the horizontal feed cam 103 is fixed to the eccentric cam 127a by the screw 4 so that the horizontal feed cam 105 is located to the right of the axis of the vertical feed shaft 1, the horizontal movement amount of the horizontal feed rod 105 is 2 ×
(C + d), and the horizontal momentum of the feed dog 18 becomes the maximum.

Further, as shown in FIG. 5B, the eccentric position of the eccentric cam 127a is set above the axis of the vertical feed shaft 1,
The horizontal feed cam 103 is set to the eccentric cam 127a so that the eccentric position of the eccentric cam 103a is to the right of the axis of the vertical feed shaft 1.
, The horizontal momentum of the horizontal feed rod 105 is approximately 2 × c, and the horizontal momentum of the feed dog 18 is substantially the same as the conventional ordinary horizontal momentum.

As described above, only by changing the fixing direction of the horizontal feed cam 103 with respect to the eccentric cam 127a, the feed dog 1
8 can freely change the maximum horizontal momentum.

It should be noted that the present invention is not limited to the above-described embodiment, but is a combination of the first and third embodiments, or the second and third embodiments. A configuration combining the embodiments may be adopted.

[0042]

According to the cloth feeding device for a sewing machine according to the first aspect of the present invention, the maximum momentum of the feed dog is variable.
To obtain the optimal momentum of the feed dog when sewing conditions such as the type and thickness of the cloth to be sewn change without preparing and reassembling several types of vertical feed cam and horizontal feed cam with different eccentricity. Can be done.

Also, the rotation speed of the main shaft of the sewing machine may be reduced only when a large amount of momentum of the feed dog is required, and the sewing machine can be driven at a high rotation speed with the normally used momentum of the feed dog, and vibration and noise of the sewing machine can be obtained. And has an excellent effect of improving sewing work efficiency.

According to the cloth feeder of the sewing machine according to the second aspect of the present invention, since the maximum vertical movement amount of the feed dog is made variable, several kinds of vertical feed cams having different eccentric amounts are prepared and rearranged. When the sewing conditions such as the type and thickness of the cloth to be sewn change, an optimum vertical movement amount of the feed dog can be obtained.

The rotation speed of the main shaft of the sewing machine may be reduced only when a large vertical movement amount of the feed dog is required. The sewing machine can be driven at a high rotation speed with the vertical movement amount of the normally used feed dog. It has an excellent effect of holding down noise and noise and improving sewing work efficiency.

According to the sewing machine cloth feeding device of the third aspect of the present invention, since the maximum vertical movement amount of the feed dog is variable, the same excellent effect as the sewing machine cloth feeding device of the second aspect is obtained. .

According to the cloth feeder for a sewing machine according to the fourth aspect of the present invention, since the maximum horizontal momentum of the feed dog is made variable, several types of horizontal feed cams having different eccentric amounts are prepared and rearranged. When the sewing conditions such as the type and thickness of the cloth to be sewn change, an optimum horizontal momentum of the feed dog can be obtained.

Further, the rotation speed of the main shaft of the sewing machine may be reduced only when a large horizontal momentum of the feed dog is required. The sewing machine can be driven at a high rotation speed with the horizontal momentum of the feed dog normally used, and the vibration of the sewing machine can be improved. It has an excellent effect of holding down noise and noise and improving sewing work efficiency.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an upper and lower feed arm according to a first embodiment in a cloth feeder of the present invention.

FIG. 2 is an exploded perspective view of an upper and lower feed arm according to a second embodiment of the cloth feeder of the present invention.

FIG. 3 is an explanatory view showing only the eccentric cams of the upper and lower feed arms of the first and second embodiments in the cloth feeder of the present invention.

FIG. 4 is an exploded perspective view of a horizontal feed rod according to a third embodiment in the cloth feeder of the present invention.

FIG. 5 is an explanatory view showing only an eccentric cam of a horizontal feed rod portion according to a third embodiment in a cloth feeder of the present invention.

FIG. 6 is a perspective view of a main part in a conventional cloth feeder.

FIG. 7 is an exploded perspective view of a horizontal feed rod in a conventional cloth feeder.

FIG. 8 is an exploded perspective view of an upper and lower feed arm in a conventional cloth feeder.

FIG. 9 is a perspective view of a main part of the conventional cloth feeder, as viewed in the direction of arrow A.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 101 Vertical feed shaft 101b Eccentric shaft 2, 12 Bearing 3, 103 Horizontal feed cam 3a, 103a Eccentric cam 5, 105 Horizontal feed rod 6, 17, 106, 117 Bearing 7 Feed adjuster 8 Horizontal feed shaft 9 Connecting arm 10 , 23, 110, 123 Thrust receiver 13 Horizontal feed arm 14, 114 Vertical feed cam 14a, 114a Eccentric cam 16, 116 Vertical feed arm 18 Feed dog 19 Feed bar 21 Vertical feed bar shaft 22 Horizontal feed bar shaft 125 Vertical eccentric cam shaft 127 Horizontal eccentric cam shaft 125a, 127a Eccentric cam a, b, c, d Eccentric amount of eccentric cam

Claims (4)

[Claims] A vertical feed shaft that rotates in conjunction with the rotation of the main shaft, a horizontal feed rod that has one end loosely fitted to an eccentric cam fixed to a rear portion of the vertical feed shaft and applies horizontal motion to a feed dog; One end of a horizontal feed rod is loosely fitted in a cloth feeder of a sewing machine having a lower end loosely fitted to an eccentric cam fixed to a front end of the vertical feed shaft and an upper and lower feed arm for giving a vertical movement to a feed dog. A cloth feeding device for a sewing machine, wherein a maximum momentum of a feed dog is variable by forming at least one of an eccentric cam and an eccentric cam into which a lower end of an upper and lower feed arm is loosely fitted. 2. A front end of the vertical feed shaft is an eccentric shaft,
The cloth feeding device for a sewing machine according to claim 1, wherein the maximum vertical movement amount of the feed dog is made variable by loosely fitting the lower ends of the upper and lower feed arms to the eccentric cam fixed to the eccentric shaft. 3. An upper and lower eccentric cam shaft having an eccentric cam is fixed to a front end of the upper and lower feed shaft, and a lower end of an upper and lower feed arm is loosely fitted to the eccentric cam of the upper and lower eccentric cam shaft.
The cloth feeder for a sewing machine according to claim 1, wherein the maximum vertical movement amount of the feed dog is variable. 4. A horizontal eccentric cam shaft having an eccentric cam is fixed to a rear portion of the vertical feed shaft, and one end of a horizontal feed rod is loosely fitted to the eccentric cam of the horizontal eccentric cam shaft, thereby maximizing a feed dog. The cloth feeding device for a sewing machine according to claim 1, wherein the horizontal momentum is variable.