JPS598687Y2 - Sewing machine feed rate adjustment device - Google Patents

Description

[Detailed description of the invention] The present invention adjusts the sewing machine feed amount by moving the feed adjustment screw, whose tip is in contact with the cam surface of one of the recesses of the approximately heart-shaped cam body, back and forth to adjust the position of the cam body. The present invention relates to a sewing machine feed amount adjustment device.

In a sewing machine feed rate adjusting device having a substantially heart-shaped cam body,
Cam body recess The sewing machine feed rate can be adjusted by moving the feed rate adjustment screw, whose tip is in contact with one cam surface, back and forth to adjust the position of the cam body. By switching the cam surface of one cam body that was in contact with the other cam surface and bringing it into contact, a reverse feed pitch that is the same as the previous feed pitch can be obtained.

A conventional sewing machine feed rate adjusting device will be explained below based on the drawings.

FIG. 1 shows a schematic diagram of a sewing machine equipped with a sewing machine feed adjustment device.

In the figure, the sewing machine frame is shown by hatching, and a feed cam 12 is fixed to the main shaft 10 supported on the sewing machine frame.
It is gripped at a.

The fork rod 14 can swing about the fork rod swing fulcrum 14b, and the swing of the fork rod root 14C is converted into rotational motion by the arm 16 and transmitted to the shaft 18, and the arm 2
0 converts the feed dog 22 into a back and forth reciprocating motion in the figure, allowing the feed dog 22 to perform a cloth feeding action.

The feed amount of the feed dog 22 is determined by displacing the position of the forked rod swing fulcrum 14b, and this positional displacement is performed by the sewing machine feed amount adjusting device 24.

FIG. 2 shows a conventional sewing machine feed rate adjusting device 24, and the hatched portion in the figure indicates a sewing machine frame or an arm machine frame.

A feed adjustment knob 28 is fixed to a feed adjustment screw 26 rotatably supported on the sewing machine frame, and a cam on one side of the recess of a substantially heart-shaped cam body 30 is attached to the tip 26a of the feed adjustment screw 26. The surfaces 30a or 30b are in contact with each other.

The upper cam surface 30a of this cam body recess is a cam surface for normal feeding, while the force cam surface 30b on the lower side of the recess is a cam surface for reverse feeding.

The cam body 30 is rotatably supported on a cam body shaft 32 supported on the sewing machine frame, and is rotated about the cam body shaft 32 by moving the feed rate adjusting screw 26 forward or backward by rotating the feed rate adjusting knob 28. It is rotatable.

The cam body 30 has an arm portion 30C in the form of an arm portion 30C.
0 C is provided with a connecting part shaft hole 30 d, and the arm part 3
A sliding portion 30e is provided at 0C.

A shaft 14d is fixed to this shaft hole 30d (in addition,
The forked rod swing fulcrum 14b is the axial center of the shaft 14d), and the shaft 14d is linked to the rotating shaft 14e of the forked rod 14 by a link 34.

A square piece 38 is loosely fitted into the sliding portion 30e, and the square piece 38 is fixed to the arm 40.

A shaft hole 40a is provided at the other end of the arm 40, and a shaft 42 rotatably supported on the arm machine frame is provided in the shaft hole 40a.
is inserted.

A spring 44 is locked to the arm machine frame and the arm 40,
The spring 44 applies a biasing force to the arm 40 in a counterclockwise direction in the figure.

On the one hand, the shaft 42 is inserted and fixed to a reverse feed lever 46, which is always urged upward in the figure by a spring 44.

Due to the biasing force of the spring 44, the tip 26a of the feed adjustment screw 26 normally comes into contact with the normal feed cam surface 30a of the cam body 30, but the reverse feed lever 46 is moved downward in the figure by the spring 44.
When the tip 26a of the feed adjustment screw 26 is pushed down against the urging force of
comes into contact.

The conventional example shown in FIG. 2 has the above structure, and its operation will be explained below.

FIG. 2 is an explanatory diagram of the cloth feeding action of the conventional example. In FIG. 3, the same members as in FIGS. 1 and 2 are given the same reference numerals.

The feed pitch is adjusted by rotating the feed amount adjustment knob 28.

When the feed rate adjustment knob 28 is rotated, the feed rate adjustment screw 2
6 is the tip 26 a of the cam body 30 for normal feeding cam surface 3
0 Move forward and backward while in contact with a.

The normal feed cam surface 30 is adjusted by advancing and retracting the feed amount adjustment screw 26.
a and the feed amount adjusting screw tip 26 a slide while in contact with each other, and the cam body 30 rotates around the cam body shaft 32 .

The rotation of the cam body 30 displaces the position of the forked rod swing fulcrum 14b, and the feed amount (or feed pitch) changes as described above.

As described above, by rotating the cam body 30 by moving the feed amount adjusting screw 26 back and forth, the position of the forked rod swing fulcrum 14b can be displaced and the feed amount (feed pitch) can be changed. .

Next, to perform reverse stitching, press the reverse feed lever 46 with the spring 44.
This is done by pulling down against the

When the reverse feed lever 46 is pulled down, the cam body 30 is rotated clockwise around the cam body shaft 32, and the forward end 26a of the feed adjustment screw comes into contact with the reverse feed cam surface 30b to maintain this state. The feed dog 22 is reversely fed.

The conventional example shown in FIG. 2 described above has the disadvantage that it is difficult to improve the precision of the slopes of the cam body recess, that is, the two cam surfaces 30a and 30b, and therefore it is not possible to precisely finely adjust the stitch pitch of the workpiece. Was.

Furthermore, when reverse stitching is performed, there is a drawback that an error occurs between the normal feed pitch and the reverse feed pitch depending on various sewing conditions such as the type and thickness of the fabric to be sewn or the pressure of the presser foot.

In addition, in order to obtain uniform and accurate stitches as shown in the conventional example shown in FIG. 2, it is necessary to spend a long time adjusting the rotation of the feed amount adjusting knob, which requires a long time for the sewing operation.

The present invention was devised in view of the above-mentioned conventional problems, and its purpose is to make it possible to quickly and easily finely adjust the stitch pitch, and to adjust the forward and reverse feed pitches so that they are equal. The purpose of the present invention is to provide a sewing machine feed amount adjustment device that can be used.

In order to achieve the above object, the present invention includes a substantially heart-shaped cam body supported on a sewing machine frame, and a substantially heart-shaped concave portion of the cam body whose tip abuts against a certain cam surface from one slope of the substantially heart-shaped recess of the cam body. In the sewing machine feed rate adjusting device, which has a feed rate adjusting screw supported on the machine frame and adjusts the sewing machine feed rate by rotating the feed rate adjusting screw, the support mechanism for the cam body supports the cam body. The eccentric has a cam body shaft that is rotatably supported, and an eccentric inner hole with respect to the center of the cam body shaft, and the cam body shaft is rotatably fitted into the eccentric inner hole and rotatably supported on the sewing machine frame. The sewing machine has a push and is characterized in that the cam body is deflected by the rotation of the eccentric push to adjust the feed amount of the sewing machine.

Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 4 shows a preferred embodiment of the present invention, and the same members as those in FIG. 2 are given the same reference numerals and their explanations will be omitted.

The cam shaft 32 is rotatably inserted into an eccentric inner hole 48 a of an eccentric pusher 48 having an inner hole 48 a eccentric with respect to the shaft center 100 of the cam shaft 32 .

A fine adjustment lever 50 is fitted into the eccentric push 48, and the fine adjustment lever 50 is fixed in a predetermined position by a set screw 34 inserted into a threaded hole drilled in the arm machine frame (not shown). .

The eccentric pusher 48 is rotatably supported on the sewing machine frame.

Fine adjustment of the sewing machine feed amount, which is the purpose of the present invention, is achieved by rotating the eccentric pusher 48 by rotating the fine adjustment lever 50, and thereby deviating the cam body axis center 100 to 100' as shown in FIG. It is carried out by

Such fine adjustment of the sewing machine feed amount is performed as follows.

Rotation of the fine adjustment lever 50 causes the eccentric push 48 to be adjusted so that the cam body axis center 100 is on the axis of the feed adjustment screw 26;
That is, it is set in advance to be in a neutral state.

Next, when the tip 26a of the feed adjustment screw 26 comes into contact with the upper cam surface 30a of the cam body recess and the main shaft 10 rotates, the fork rod 14 swings about the fork rod swing fulcrum 14b.

At this time, when the reverse feed lever 46 is pulled down, the tip of the feed adjustment screw 15 comes into contact with the lower cam surface 30b of the cam body recess, thereby performing reverse feed with the same amount of feed as the normal feed.

However, the concave cam surfaces 30a, 30 of the cam body 30
Depending on the sewing conditions such as machining dimensional error of b and sewing material,
The forward feed pitch and the reverse feed pitch are not the same, and some errors occur.

Therefore, in order to correct this error, the fine adjustment lever 50
is rotated, and the eccentric push 48 is rotated to deviate the cam body axis center 100 to a new cam body axis center 100'.

Due to this deviation toward the cam body axis center 100', the contact position of the tip 26a of the feed adjustment screw 26 that is in contact with the recessed cam surface 30a or 30b of the cam body 30 changes, and the forked rod swing fulcrum changes. 14b is also deflected to 14b'.

As a result of the deviation of the forked rod swing fulcrum 14b in this way,
The operating range of the arms 16 and 20 changes, and the reciprocating range of the feed dog 22 is adjusted.

Note that when the bifurcated rod swing fulcrum 14b moves counterclockwise, the forward feed amount becomes large and the reverse feed amount becomes small, and when it moves clockwise, the opposite occurs.

As explained above, in the present invention, the feed amount can be finely adjusted by deflecting the axis center 100 of the cam body shaft 32 by the rotation of the eccentric pusher 48, and the forward feed amount and the reverse feed amount can be made equal. It has the advantage of being able to

As a result, it is possible to always sew with the same forward and reverse feed amounts and a uniform forward and reverse stitch pitch, making it possible to obtain sewn products with beautiful seams and high commercial value. It has the advantage that it can be quickly and easily adjusted in response to changes in sewing conditions or changes in the feed pitch caused by switching between forward and reverse feed.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a sewing machine equipped with a conventional sewing machine feed amount adjustment device, Fig. 2 is a schematic diagram showing a conventional sewing machine feed amount adjustment device, and Fig. 3 is a diagram illustrating the operation of the conventional example in Fig. 2. FIG. 4 is a schematic view showing a preferred embodiment of the present invention, and FIG. 5 is an explanatory diagram of the operation of the embodiment shown in FIG. In each figure, the same members are given the same reference numerals, 14b is the bifurcated rod swing fulcrum, 26 is the feed rate adjustment screw, 26a is the tip of the feed rate adjustment screw, 28 is the feed rate adjustment knob, and 30 is approximately the heart. 30a is a cam surface for normal feeding, 30b is a cam surface for reverse feeding, 32 is a cam body axis, 100 is a center of the cam body axis, 4
6 is a reverse feed lever, 48 is an eccentric push, 48a is an eccentric hole, and 50 is a fine adjustment lever.

Claims (1)

[Scope of utility model registration request] a substantially heart-shaped cam body supported by the sewing machine; and a feed rate adjusting screw supported by the sewing machine frame, the tip of which contacts a certain cam surface from one slope of the substantially heart-shaped recess of the cam body. In the sewing machine feed rate adjusting device, which adjusts the sewing machine feed rate by rotating the feed rate adjusting screw, the support mechanism for the cam body includes a cam body shaft that rotatably supports the cam body, and a cam body shaft that rotatably supports the cam body; The cam body shaft is rotatably fitted into the eccentric inner hole and is rotatably supported on the sewing machine frame. 1. A sewing machine feed amount adjusting device, which adjusts the sewing machine feed amount by deflecting a cam body by motion.