JPH04371189A - Sewing machine - Google Patents

Abstract

PURPOSE:To provide a settling mechanism for a feed dog to a sewing machine equipped with a detachable embroidery frame feeder so as to prevent the settling of the feed dog during embroidery from being forgotten. CONSTITUTION:An eccentric cam 45 is mounted on the lower shaft 43 of a sewing machine in such a manner as being slidable in the direction of its axis and rotatable integrally with the shaft and a flange portion 45a is formed on one side of the eccentric cam 45 and a concentrical cam portion 45b on the other side. A vertically shiting lever 47 which puts a feed dog 25 in vertical motion is placed on the eccentric cam 45. A horizontally turning lever 55 is provided which has at one end a protrusion 59 on which the flange portion 45a is made to abut and has at the other end a working protrusion 13 exposed to the coalescence face of an embroidery frame feeder and the horizontally turning lever 55 is put in a turning movement by the pushing piece S3 of the embroidery frame feeder so as to move the eccentric cam 45 and the vertically shifting lever 47 is supported by the concentric cam portion 45b.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine that performs embroidery stitches by incorporating an embroidery frame feeding device that freely moves an embroidery frame loaded with work cloth.

0002

2. Description of the Related Art Conventionally, sewing machines equipped with an embroidery frame feeding device (for example, Japanese Unexamined Patent Publication No. 2-80084) have been equipped with a sinking mechanism for sinking the feed dog below the throat plate. The sinking mechanism releases the vertical movement mechanism that moves the feed dog up and down by moving a lever, and causes the feed dog to sink below the throat plate. In conventional sewing machines, the lever of the sinking mechanism is connected to an externally exposed switching lever. The operator operates this external switching lever to lower the feed dog below the throat plate, and then attaches the embroidery frame feed device to the sewing machine. When the feed dog sinks below the throat plate, the movement of the embroidery frame carried out by the embroidery frame feeder is not hindered by the feed dog, and works together with the vertical movement of the sewing machine's sewing needle to move the workpiece cloth attached to the embroidery frame as desired. embroidery is formed.

0003

However, the conventional sewing machine described above has a problem in that the operator sometimes forgets to operate the switching lever. If you forget to operate the switching lever and operate the embroidery frame feed device with the feed dog protruding from the throat plate, the feed dog will interfere with the workpiece cloth attached to the embroidery frame, making it impossible to embroidery properly.

The purpose of the sewing machine of the present invention is to solve the above-mentioned problems and to eliminate the possibility of erroneous operation such as forgetting to lower the feed dog.

[0005]

[Means and effects for solving the problems] A sewing machine of the present invention executes embroidery stitches by combining an embroidery frame feeding device for moving an embroidery frame on which a workpiece cloth is attached, wherein the embroidery frame feeding device moves the embroidery frame. An operating piece that is provided on the combining surface of the sewing machines to be combined and moves its position when the embroidery frame feed device is combined, and a vertical movement mechanism that moves the feed dog of the sewing machine up and down are released by moving a lever, and the feed dog moves to the needle. It is characterized by comprising a sinking mechanism that sinks from the plate, and a connection mechanism between the action piece and the lever that moves a lever of the sinking mechanism by movement of the action piece.

In the above structure, when the embroidery frame feeding device is combined with the sewing machine, the operating piece provided on the combined surface of the sewing machine moves. The movement of the action piece is transmitted to the lever of the lowering mechanism by the coupling mechanism, causing the lever of the lowering mechanism to move. By moving this lever, the sinking mechanism releases the vertical movement mechanism and sinks the feed dog from the throat plate. In other words, if the embroidery frame feed device is combined, the feed teeth of the sewing machine will automatically sink. Therefore, the operation of lowering the feed dog becomes unnecessary, and there is no possibility of erroneous operation.

[0007]

[Embodiment] An embodiment of the present invention will be described below. FIG. 1 shows a state in which an embroidery frame feeding device S is attached to a free arm 2 of a sewing machine 1. The embroidery frame feeding device S places the embroidery frame S1 on the upper surface of the throat plate 3 of the sewing machine 1, and controls the positioning of the embroidery frame S1 in two axial directions. This positioning control of the embroidery frame S1 and the vertical movement of the sewing needle 7 attached to the needle bar 5 of the sewing machine 1 work together to form embroidery on the work cloth. A presser foot 11 for embroidery is attached to the presser foot 9 of the sewing machine M in advance.

An operating protrusion 13 is provided on the lower surface of the free arm 2 as a mechanism for lowering the feed dog 25 (FIG. 2) of the sewing machine 1. The working protrusion 13 protrudes inside a recess 15 provided on the lower surface of the free arm 2 for protection. The embroidery frame feeding device S includes a push-out piece S3 that moves the working protrusion 13 of the sewing machine 1.
is provided.

As shown in the perspective view of FIG. 2, the feed dog 25 sinking mechanism 20 includes a back and forth feed drive mechanism 21 that moves the feed dog 25 of the sewing machine back and forth, and a vertical feed drive mechanism 23 that moves the feed dog 25 up and down. organized around. Prior to explaining the sinking mechanism 20, the outline of the longitudinal feed drive mechanism 21 and the vertical feed drive mechanism 23 of the feed dog 25 will be explained below. FIG. 3 is a plan view, FIG. 4 is a front view, and FIG. 5 is a left side view.

[0010] The feed dog 25 is fixed to the upper surface of the feed base 27. The feed table 27 is given back and forth motion by the back and forth feed drive mechanism 21 . The back and forth feed drive mechanism 21 includes a swing arm 29
It consists of a horizontal feed arm 31, and the like. The swinging arm 29 is swingably supported by a lower support shaft 33. The swinging arm 29 is given a swinging motion about the support shaft 33 by a swinging drive section (not shown). A support shaft 35 is supported on the upper part of the swing arm 29, and as the swing arm 29 swings, the support shaft 35 also reciprocates in the front-rear direction.

Two bearings 31 at the rear of the horizontal feed arm 31
a and 31b are rotatably supported by a support shaft 35. The horizontal feed arm 31 includes a roller 31c at its front end. roller 31
c is supported by the support surface 37. A tension spring 39 is tensioned between the side surface of the horizontal feed arm 31 and the lower frame. The tension spring 39 urges the horizontal feed arm 31 downward to bring the roller 31c into close contact with the support surface 37. Therefore, as the support shaft 35 reciprocates back and forth, the horizontal feed arm 31 moves back and forth almost horizontally, and the feed dog 2 on the feed base 27
5 is given forward and backward feed.

The vertical feed drive mechanism 23 includes a guide rod 41
, a lower shaft 43, an eccentric cam 45, a vertically moving lever 47, etc. The guide rod 41 is connected to the bearing portion 3 of the horizontal feed arm 31.
It is fixed to 1c in a vertically protruding state. The axis of the guide rod 41 and the plate surface of the horizontal feed arm 31 intersect perpendicularly. The upper part of the guide rod 41 penetrates the upper part of the feed table 27, and the lower part of the guide rod 41 penetrates the guide part 27a extending below the feed table 27. In this way, the feed base 27 is supported by the guide rod 41 so as to be movable in its axial direction.

A timing belt is attached to a pulley of the lower shaft 43, and the lower shaft 43 is rotated in synchronization with the upper shaft for moving the sewing needle 7 up and down. The eccentric cam 45 is a cam provided eccentrically on the lower shaft 43. The amount of eccentricity is determined in accordance with the vertical movement stroke of the feed dog 25. Details of the eccentric cam 45 will be described later.

The vertical movement lever 47 has a front end formed by a rod 49.
The lower surface of the abdomen contacts the eccentric cam 45. A roller 49 is rotatably supported on the side surface of the rear end of the vertically movable lever 47. A support surface 27b provided on the lower surface of the feed table 27 comes into sliding contact with the roller 49. Guide portion 27a of feed base 27 and bearing portion 31b of horizontal feed arm 31
A compression spring 51 is arranged between the feed base 27 and
is urged downward.

Therefore, when the lower shaft 43 rotates, the roller 49 of the vertically moving lever 47 moves up and down in accordance with the outer peripheral shape of the eccentric cam 45. As a result, the feed dog 25 fixed to the upper part of the feed table 27 is given vertical feed. Next, the sinking mechanism 20 will be explained.

A flange portion 45a and a concentric cam portion 45b are integrally formed on both sides of the eccentric cam 45 of the vertical feed drive mechanism 23. The outer diameter of the concentric cam portion 45b is the same as the minimum diameter of the eccentric cam 45 (the shortest distance from the center of the lower shaft 43). Therefore, a portion of the surface 45c is formed between the eccentric cam 45 and the concentric cam portion 45b. As shown in FIG. 3, a notch 45d is formed inside the concentric cam 45b in the axial direction of the lower shaft 43. A pin 46 that engages with this notch 45d is attached to the lower shaft 43. With this configuration, the eccentric cam 45, the flange portions 45a on both sides thereof, and the concentric cam portions 45b do not rotate relative to the lower shaft 43, but can freely slide in the axial direction of the lower shaft 43.

Flange 45a of eccentric cam 45 and lower shaft 43
A compression spring 53 is interposed between the bearing portion 43a and the bearing portion 43a. The compression spring 53 urges the eccentric cam 45 toward the vertically movable lever 47 to position the eccentric cam 45 on the lower surface of the abdomen of the vertically movable lever 47 . Below the compression spring 53 is a horizontal rotation lever 55.
is arranged so as to be swingable in the horizontal direction by a shaft 57. On the lower surface of the end of the horizontal rotation lever 55, the above-mentioned operating protrusion 13 is provided.
is provided. Further, on the upper surface of the other end of the horizontal rotation lever 55, an abutment protrusion 59 that abuts against the flange portion 45a of the eccentric cam 45 is provided. Horizontal rotation lever 55
is pulled by a tension spring 61 fixed to a frame (not shown), and the contact protrusion 59 is urged toward the flange portion 45 side. Note that the spring constant of the tension spring 61 is smaller than the spring constant of the compression spring 53.

Next, the operation of the sewing machine having the above configuration will be explained. When the upper shaft (not shown) rotates by the sewing machine motor, the lower shaft 43 rotates in synchronization with the rotation of the upper shaft. Lower axis 4
3, the vertical movement lever 47 moves up and down along the outer circumferential shape of the eccentric cam 45, and the vertical movement is applied to the feed dog 25. The feed dog 25 protrudes from the throat plate 3 in the raised position, and is moved in a predetermined direction by the operation of the front-rear feed drive mechanism 21 to close the throat plate 3.
Transfer the processed fabric on the surface. The feed dog 25 sinks below the throat plate 3 in the lowered position, and the front and rear positions return to the positions before the work cloth is transferred by the operation of the front and rear feed drive mechanism 21.

When the embroidery frame feed device S is attached to the sewing machine 1, the push-out piece S3 provided on the embroidery frame feed device S pushes out the working protrusion 13 of the sewing machine in the direction of arrow A in FIG. 6, and swings the horizontal rotation lever 55. . Then, the abutting protrusion 59 touches the flange portion 4.
5a is moved against the pressing force of the compression spring 53, and the concentric cam portion 45b is disposed at the lower part of the sub-portion of the vertically movable lever 47. Since the concentric cam portion 45b has the same outer diameter as the minimum diameter of the eccentric cam 45, in this state, even if the lower shaft 43 rotates,
The vertical movement lever 47 does not rise. That is, as shown in FIGS. 7 and 8, the feed dog 25 maintains a state sunk below the throat plate 3.

When the embroidery frame feed device S is attached to the sewing machine 1, the feed dog 25 is sunk below the throat plate 3, so the embroidery frame S1 of the embroidery frame feed device S can be moved without being obstructed by the feed dog 25. The movement and the vertical movement of the sewing needle 9 of the sewing machine work together to form a desired embroidery on the work cloth mounted on the embroidery frame S1.

When the embroidery frame feeder S is removed from the sewing machine 1,
The extrusion piece S3 is separated from the working protrusion 13. Then, the compression spring 53 urges the eccentric cam 45 toward the lower side of the secondary portion of the vertically movable lever 47. Since there is a surface portion 45c between the eccentric cam 45 and the concentric cam portion 45b, when the surface portion 45c rotates to the vertical movement lever 47 position due to the rotation of the lower shaft 43, the biased eccentric cam 45 moves to the lower part of the sub-portion of the vertically moving lever 47. After this, the vertically movable lever 47 is moved up and down by the eccentric cam 45, and the work cloth can be fed so that the feed dog 25 protrudes from the throat plate 3.

According to the sewing machine described above, by simply installing the embroidery frame feed device S on the sewing machine, the feed dog 25 can be moved to the needle plate 3.
Since the feed dog 25 is lowered more automatically and the operation of lowering the feed dog 25 is not necessary, the possibility of erroneous operation can be fundamentally eliminated. Although the embodiments have been described above, the present invention is not limited to the embodiments in any way, and it goes without saying that it can be implemented in various forms without departing from the spirit of the invention.

[0023]

[Effects of the Invention] As detailed above, according to the sewing machine of the present invention, it is possible to realize a configuration in which the feed dog of the sewing machine automatically sinks when the embroidery frame feeding device is combined with the sewing machine. This eliminates the need for operations and eliminates erroneous operations.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing essential parts of a sewing machine according to the present invention.

FIG. 2 is a perspective view showing a mechanism for lowering the feed dog.

FIG. 3 is a plan view of the sinking mechanism.

FIG. 4 is a front view of the sinking mechanism.

FIG. 5 is a left side view of the sinking mechanism.

FIG. 6 is a plan view of the sinking mechanism when the feed dog is in a sinking state.

FIG. 7 is a front view of the sinking mechanism when the feed dog is in a sinking state.

FIG. 8 is a left side view of the sinking mechanism when the feed dog is in a sinking state.

[Explanation of symbols]

2... Sewing machine arm, 3... Throat plate, 7
...Sewing needle, 13...Working protrusion, 25...Feed dog, 4
5... Eccentric cam, 45b... Concentric cam,
S...Embroidery frame feeding device,

Claims (1)

[Claims] 1. A sewing machine that performs embroidery stitching by combining an embroidery frame feed device that moves an embroidery frame with a work cloth mounted thereon, the embroidery frame feed device is provided on a combined surface of the sewing machine to which the embroidery frame is attached, and the embroidery an action piece that moves the position by combining the frame feed device; a sinking mechanism that releases the vertical movement mechanism that moves the feed dog of the sewing machine up and down by moving a lever, and sinks the feed dog from the throat plate; A sewing machine comprising: a coupling mechanism between the lever and the operating piece that moves the lever of the sinking mechanism by movement.