JPH0113874B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention comprises a plurality of stitch cams, at least one feed control cam, a cam follower that selectively engages with each cam and swings, and each cam follower. a cam selection device for engaging each of the cams corresponding to a desired stitch pattern; and a feed dog sinking device operable to move the feed dog from an active position to a non-active position. The present invention relates to a feed dog sinking mechanism.

Prior Art In a conventional zigzag sewing machine, a cam selection device is operated to select a pattern cam and a feed control cam corresponding to a desired stitch pattern with the work cloth positioned on the work cloth support surface of the sewing machine bed. Normally, the cam selection device is activated after the needle is placed in the upper position, so the feed dog is placed in a raised position protruding from the upper surface of the needle, and each cam is followed by the action of the release cam of the selection device. It is separated from each child cam, and the feed dog is moved back and forth in conjunction with this. Therefore, if the work cloth has been positioned before the stitch pattern selection operation, the once positioned work cloth will shift from the predetermined position due to the forward and backward movement of the feed dog, and it will be necessary to position the work cloth again. It was a hassle. In addition, after forming a predetermined stitch, when a pattern is selected using the cam selection device in order to continuously form stitches of a different pattern from the predetermined stitch, the feed dog moves back and forth as described above to A positional shift occurs. Therefore, if the sewing operation is continued, the edges of each stitch pattern will not match, and each stitch pattern will be formed discontinuously.
There was a risk that partial thread tightness would occur and the aesthetic appearance of the seams would be spoiled.

Purpose This invention was made in order to eliminate the above-mentioned defects, and its purpose is to cause each cam follower to be relayed from each cam by the relay cam of the cam selection device when selecting various stitch patterns. The feed dog is lowered from the working position to the non-working position before the pattern is selected, which prevents the workpiece cloth from shifting its position when selecting a pattern, and saves the trouble of repositioning the workpiece cloth once it has been positioned. Provides a feed dog sinking mechanism for a novel zigzag sewing machine that can form aesthetically pleasing seams by matching the ends of the seam patterns when consecutively forming a plurality of different seam patterns. It's about doing.

Embodiment Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings.As shown in FIG. a plurality of patterned cams 2 for imparting a pattern, and a plurality of pattern cams 2 for controlling the feed movement of a feed dog 28, which will be described later.
Feed control cam 3, buttonhole feed cam 4
and a gear 5 are integrally inserted and supported, and each of the cams 2, 3, and 4 is decelerated in conjunction with the main shaft by meshing the gear 5 with a gear (not shown) fixed to the main shaft of the sewing machine. be rotated. a fixed shaft 6 inserted into the sewing machine frame so as to extend parallel to the camshaft 1;
First and second swing frames 7 and 8, which are substantially U-shaped, are supported so as to be swingable but immovable in the axial direction. First and second cam followers 9 and 10 are supported on the fixed shaft 6 so as to be movable in the axial direction at their base ends so as to be located within the first and second swing frames 7 and 8. The connecting shafts 7a and 8a fixed to the first and second swing frames 7 and 8 are connected to each cam follower 9 and 1.
0 is inserted.

Each cam follower 9, 10 is connected to each swing frame 7,
The first cam follower 9 can be moved to any one of the pattern cams 2, and the second cam follower 10 can be moved to any one of the pattern cams 2 by the action of a cam selection device to be described later. It can engage with the control cam 3 or the buttonhole feed cam 4, respectively, and is always pressed against each of the cams by a predetermined spring means. Further, the first swing frame 7 is operatively connected to a needle bar support frame (none of which is shown) that supports the needle bar via a known swing link or the like, and the first cam follower 9 The rocking motion is transmitted to the needle bar, imparting a predetermined lateral rocking motion to the needle bar. On the other hand, the second swing frame 8 is operatively connected to a feed adjustment member (none of which is shown) via a feed control lever, a connecting rod, etc.

Next, to explain the cam selection device, a bracket 11 is attached to the sewing machine frame with a plurality of screws (not shown), and as shown in FIG. 2, an operating shaft 1 is rotatably supported by the bracket 11.
A manual operation member 13 projecting outward from the sewing machine frame is fixed to one end of the sewing machine frame 2, and a gear 14 located inside the bracket 11 is fixed to the other end. A support shaft 15 is rotatably supported on the bracket 11 so as to extend parallel to the operation shaft 12. As shown in FIGS. 1 and 2, the support shaft 15 has a release cam having a gear portion 16a on one side. 16 is supported so as to be integrally rotatable, and its gear portion 16a meshes with the gear 14. A release lever 1 is attached to the bracket 11 by a shaft 17.
8 is pivotally mounted, and a contact pin 18a at the tip thereof is pressed against the cam surface of the release cam 16 by an appropriate spring action. Furthermore, an engaging portion 18b is formed on the upper edge of the release lever 18 so that it can be engaged with each inner extension portion (not shown) of the first and second swing frames 7 and 8 from below. It's summery.

The support shaft 1 is adjacent to the release cam 16.
A selection cam 19 is fitted into the support shaft 15 so as to be able to rotate integrally with the support shaft 15, and on both sides thereof a first cam surface 19a for selecting the pattern cam 2 and a feed control cam 3 or a feed cam for buttonholes are provided. A second cam surface 19b for selecting No. 4 is formed respectively. First and second moving levers 22 and 23 are rotatably supported by shafts 20 and 21 on the bracket 11, and a first cam surface of the selection cam 19 is provided at an intermediate portion of the first moving lever 22. A contact pin 22a that engages with the contact pin 19a is implanted, and a pin 22b that fits into the base end of the first cam follower 9 is implanted at its tip. Further, a contact head 23a that engages with the second cam surface 19b of the selection cam 19 is formed in the intermediate portion of the second moving lever 23, and a contact head 23a that engages with the second cam surface 19b of the selection cam 19 is formed at the tip thereof. A pin 23b that fits into the base end is implanted. Then, by an appropriate spring action, the contact pin 22a and the contact head 23a are attached to the corresponding cam surface 19.
a, 19b are pressed against each other.

Therefore, when the manual operation body 13 is rotated, the gear 14 and the gear portion 16a of the release cam 16 are rotated.
Release cam 16 and selection cam 1
9 is rotated, first, the first and second swing frames 7 and 8 are rotated counterclockwise in FIG. 1 by the action of the release lever 18, and thereby the first and second cam followers 9 , 10 are separated from each cam 2, 3, and 4, respectively. Next, the first and second moving levers 2
2 and 23, both the cam followers 9 and 10
are individually moved along the fixed shaft 6, and any cam can be selected.

The configuration of the cam selection device is described in Japanese Unexamined Patent Publication No. 103549/1989 filed by the same applicant as this application, so further explanation will be omitted.

Next, the configuration of the feed dog lowering device operably connected to the presser foot lifting mechanism will be explained according to FIGS. 3 to 5. The head of the sewing machine frame has a presser foot at the lower end, and A presser bar 2 equipped with a presser bar holder 24a
4 is supported so as to be movable up and down, and an actuation plate 25 having an actuation protrusion 25a on the upper part is inserted into the presser rod 24 so as to be movable up and down. A presser foot lifting lever 26 equipped with a cam portion 26a capable of engaging with a presser foot bar holder 24a and an operating plate 25 is rotatably supported at the head of the sewing machine frame. When rotated in the direction of the arrow, the actuating plate 25 is raised together with the presser foot 24 and the presser foot, and is held at the raised position. Then, the presser bar 2
4. The actuating plate 25, the presser foot lifting lever 26, etc. constitute a cloth presser foot lifting mechanism. A feed table 27 is supported within the bed portion of the sewing machine frame, and is reciprocated in the front and rear directions via the feed adjustment member by a well-known horizontal feed cam (not shown) that rotates in conjunction with the main shaft of the sewing machine. A feed dog 28 is fixed on the feed base 27 and can be retracted onto the bed portion. The feed bar 27 is rotatably biased in the direction in which the feed dog 28 sinks by a spring (not shown) provided between a part of the feed bar and the bed section, and the lower limit position thereof is on the feed bar 27. This is regulated by engagement between a provided stopper 29 and a part of the bed.

As shown in FIGS. 4 and 5, a vertical feed arm 31 is rotatably supported by a shaft 30 below the feed base 27, and an accommodation hole 31a is formed at the tip of the arm 31. spring 32
An engaging pin 33 is housed therein, and is urged outwardly by the locking pin 33 . Further, this vertical feed arm 31 is reciprocated in the vertical direction by a vertical feed cam 34. A vertical feed plate 36 is rotatably attached to the intermediate portion of one side of the vertical feed arm 31 by a stepped screw 35, and a fitting hole 36 that can match the accommodation hole 31a is provided at the tip end of the vertical feed plate 36.
A is transparent. An eccentric screw 37 is rotatably attached to the intermediate portion of the vertical feed plate 36, and a roller 38 is rotatably fitted and supported on the eccentric shaft portion. A clamping plate 3 is provided at the front end of the feed base 27.
9 is fixed with a screw 40, and the roller 38 is held between this holding plate 39 and the feed base 27. Further, the feed table 27, the vertical feed arm 31, the engagement pin 33, the vertical feed plate 36, and the like constitute a feed dog sinking device.

When the accommodation hole 31a of the vertical feed arm 31 and the fitting hole 36a of the vertical feed plate 36 match, the head 33a of the engagement pin 33 is fitted into the fitting hole 36a by the biasing force of the spring 32. is,
The vertical feed arm 31 and the vertical feed plate 36 are integrally coupled, and the feed dog sinking device is held in an inoperative state. In this state, the feed table 27 is held in the upper operating position via the rollers 38, and vertical movement is imparted to the feed table 27 via the vertical feed arm 31 and the vertical feed plate 36 due to the rotation of the vertical feed cam 34. At the same time, the rotation of the horizontal feed cam imparts back-and-forth motion to the feed table 27, and the feed dog 28 performs a well-known feed movement. Further, when the head 33a of the engagement pin 33 is disengaged from the fitting hole 36a and the feed dog sinking device is maintained in the operating state, the connection between the vertical feed arm 31 and the vertical feed plate 36 is released. Then, as shown in FIG.
is lowered from the top of the bed.

When the presser foot lifting lever 26 is rotated as described above, the operating protrusion 25a of the operating plate 25
The two-arm lever 41 is rotated in the direction of the arrow in FIG. 47 will be moved up. The upward movement of the connecting rod 47 causes the operating lever 4 on the mounting plate 45 to
6, the operating rod 48 is moved in the direction of the arrow in FIG. 3, and as shown in FIG.
The head 33a of the vertical feed plate 36 is disengaged from the fitting hole 36a of the vertical feed plate 36, and the feed dog 28 is lowered together with the feed base 27.

The structure of the feed dog lowering device is described in Japanese Patent Application Laid-Open No. 56-20490 by the same applicant as this application, so further explanation will be omitted.

Next, a description will be given of the control cam 50 that is rotated in conjunction with the operation of the cam selection device, and the linking means for operating the feed dog sinking device by the action of the control cam 50.

As shown in FIGS. 1 and 2, a control cam 50 is fitted and supported on the support shaft 15 adjacent to the selection cam 19 so as to be rotatable integrally with the support shaft 15, and on both sides of the control cam 50 is provided A first cam groove 50a for changing the feed amount of the feed dog 28 and a second cam groove (not shown) for changing the feed amount of the feed dog 28 are formed. Further, a control cam 50 is used to operate the feed dog sinking device in conjunction with the operation of the cam selection device.
A third cam surface 50b consisting of the same number of peaks and valleys as the plurality of pattern cams 2 is formed on the outer periphery of the cam. The operation of the feed dog tooth sinking device is caused by the action of the release cam 16 on each cam follower 9, 10.
Each cam surface 50b of the control cam 50 and the release cam 16 is
The operating phase of the control cam 16b is set, and the control cam 50 is rotated one pitch each time a predetermined stitch pattern is selected by the cam selection device.

First and second connecting levers 52 and 53 are rotatably supported on the bracket 11 by a pivot 51, and a first cam of the control cam 50 is mounted at an intermediate portion of each connecting lever 52 and 53. Groove 50
Contact pins 52a (only one is shown) that fit into the a and second cam grooves are implanted, and the tips of each connecting lever 52, 53 are connected to a well-known amplitude adjuster and a feed adjuster, respectively. . Also, the second
As shown in the figure, a contact 54 is attached to the pivot shaft 51 near the base end of the first connecting lever 52.
A tension spring 55 is fixed to the control cam 50 so as to be able to rotate integrally with the control cam 50, and is suspended between the pivot shaft 51 and the bracket 11 on one side of the bracket 11. The cam surface 50b is biased towards the cam surface 50b and is normally pressed against the trough portion of the cam surface 50b. On one side of the bracket 11, an elongated hole 56 extending vertically is provided at the end of the pivot shaft 51.
An actuating plate 56 having a shape is fixed to the pivot shaft 51 so as to be rotatable therewith. The long hole 56a of this actuating plate 56
The protrusion 47a of the connecting rod 47 is inserted into the inside,
Normally, the protrusion 47a is engaged with the lower inner end surface of the elongated hole 56a. The actuating lever 46, the connecting rod 47, the actuating rod 48, the contact 54, the actuating plate 56, and the like constitute a linking means for linking the control cam 50 and the feed dog lowering device.

Therefore, when the control cam 50 is rotated by one pitch from an arbitrary valley on the third cam surface 50b to the next valley in conjunction with the operation of the cam selection device, the contactor 54
And the actuating plate 56 is reciprocated. And the second
As shown in the figure, when the contact 54 moves forward and engages the peak of the third cam surface 50b, the actuating plate 56
The lower inner end surface of the elongated hole 56a and the protrusion 4 of the connecting rod 47
The connecting rod 47 is moved upward based on the engagement with 7a,
The feed dog lowering device is activated and the feed dog 28 is lowered. Subsequently, when the contactor 54 moves back and engages from the peak to the next trough, the elongated hole 56a allows the actuating plate 56 to move back, and the connecting rod 4
7 is held in the upward movement position, the feed dog lowering device is held in an operating state, and the protrusion 47a is engaged with the upper inner end surface of the elongated hole 56a. When the sewing machine is operated in this state and the first needle penetrates the work cloth, the feed dog sinking device automatically returns to the inactive state based on the rotation of the horizontal feed cam and the vertical feed cam 34. As a result, a feeding motion is applied to the feed dog 28, and the connecting rod 47 is moved downward so that its protrusion 47a engages again with the lower inner end surface of the elongated hole 56a.

In this embodiment, the protrusion 47a of the connecting rod 47 is always aligned with the elongated hole 56 of the actuating plate 56.
Since it is engaged with the inner end surface of the lower part of a, it is possible to allow the connecting rod 47 to move upward based on the operation of the presser foot lifting mechanism, and the feed dog lowering device can be operated independently of the operation of the cam selection device. can be activated.

Next, the operation of the zigzag sewing machine configured as described above will be explained.

Now, in FIG. 1, the feed dog 28 is placed in the upper working position and the protrusion 47 of the connecting rod 47 is shown in FIG.
5A shows a state in which the portion a is engaged with the lower inner end surface of the elongated hole 56a of the actuating plate 56. Further, the contactor 54 shown in FIG.
It engages with the valley of b. In this state, when the manual operation unit 13 of the cam selection device is rotated to form a desired stitch pattern, the release cam 16, selection cam 19, and control cam 50 are rotated integrally. Then, the release cam 16 and the control cam 50
Based on the operating phase difference, the feed dog lowering device is activated prior to the release movement of each cam follower 9,10.

That is, as shown in FIGS. 2 and 3, the contact 5 is moved by the action of the third cam surface 50b of the control cam 50.
4, the actuating plate 56 is integrally reciprocated, and based on the engagement between the actuating plate 56 and the connecting rod 47, the connecting rod 47 is moved upward when the contactor 54 moves forward. Then, the third actuating rod 48 is activated via the actuating lever 46.
It is moved in the direction of the arrow in the figure, the engagement pin 33 of the feed dog lowering device sinks into the accommodation hole 31a of the upper and lower feed arm 31, the feed dog 28 sinks, and the feed dog 28 is placed in a non-operating position. . Thereafter, by the action of the release engagement 16, the first cam follower 9 moves the pattern cam 2 through the release lever 18 and the respective swing frames 7 and 8.
The second cam follower 10 separates from the feed control cam 3 or the buttonhole feed cam 4. Next, each cam follower 9, 10 is individually moved along the fixed shaft 6 by the action of the selection cam 19, and each desired cam is selected.

Therefore, in a state where the feed dog 28 is disposed in the non-acting position, the feed dog 28 is moved back and forth in conjunction with the release movement of each cam follower 9, 10, and the feed dog 28 acts on the work cloth. Therefore, there is no need to position the work cloth, and there is no need to newly perform the positioning each time a stitch pattern is selected. Then, when the sewing machine starts operating in this state and the first stitch passes through the work cloth, the feed dog sinking device returns to the inactive state based on the rotation of the horizontal feed cam and the vertical feed cam 34. The feed dog 28 imparts a feed motion to the work cloth, making it possible to form a desired stitch pattern. Further, with the return operation of the feed dog lowering device, the connecting rod 47 and its protrusion 47a are moved down within the elongated hole 56a of the actuating plate 56 and returned to the original position. Furthermore, when consecutively forming a seam pattern with a shape different from this seam pattern, as mentioned above, the position of the workpiece cloth does not shift when selecting the pattern, so the edges of both seam patterns It is possible to form a continuous pattern with a good appearance in which the patterns match.

Next, another example of the present invention will be described with reference to FIG. 6. In this example, the third cam surface 50b of the control cam 50 is used for basting stitches and stitching stitches having a larger angular range than the peak part. cam surfaces 57, 58
This embodiment differs from the previous embodiment in that , respectively, are formed. Therefore, in this other example, when the pattern cam 2 and the feed control cam 3 for basting or stitching are selected by the manual operation unit 13 of the cam selection device, the rotation of the control cam 50 causes Due to the action of the cam portions 57 and 58,
Even after the actuating plate 56 is moved to the forward position together with the contact 54 prior to the release movement of each cam follower 9, 10, it is held at the forward position, and the connecting rod 47
is restrained in the upward movement position, and the feed dog sinking device is restrained in the operating state. Therefore, the feed dog 28 is maintained in a depressed state without requiring any special manual operation, and basting and stitching can be performed immediately.

Effects As described in detail above, the present invention includes a control cam that rotates in conjunction with the operation of the cam selection device, and includes a contact that engages with the control cam, and which rotates according to the cam surface shape of the control cam. Coupling means for operating the feed dog sinking device is provided, and the actuation of both cams is such that the feed dog sinking device is actuated by the action of the control cam prior to the release movement of the cam follower by the action of the release cam of the cam selection device. The phase is set, and the feed dog sinking device is configured so that it can return to the inactive state after the first needle drops when the sewing machine starts operating after operating the cam selection device, so that the cam selection operation is always set to the feed dog. By performing this in a depressed state, it is possible to prevent the work cloth from shifting its position when selecting a pattern, and to save the effort of repositioning the work cloth that has been once positioned.
Therefore, it is easy to set the sewing start position at the beginning of sewing, and when forming multiple seam patterns with different shapes in succession, the ends of the seam patterns can be aligned to create a good aesthetic appearance. It has the excellent effect of being able to form seams.

Note that the cam selection device is not limited to the configuration in the embodiment, and may be of any type, for example,
A type that uses the driving force of a motor may also be used.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of essential parts of a zigzag sewing machine embodying the present invention, Fig. 2 is an exploded perspective view showing an enlarged cam selection device, control cam, etc., and Fig. 3 is a presser foot lifting mechanism and feed dog. FIG. 4 is a front view of the feed dog sinking device, and FIG. 5 is a partially exploded perspective view showing the sinking device.
The figure is a partial sectional view of the feed dog lowering device, and FIG. 6 is a perspective view showing the main parts of another example of the present invention. Pattern cam 2, feed control cam 3, first cam follower 9, second cam follower 10, release cam 1
6. Selection cam 19 (these 16 and 19 are included in the cam selection device), feed dog 28, control cam 50, contactor 54 (this 54 is included in the linking means).

Claims (1)

[Claims] 1. To selectively form a plurality of stitch patterns,
A plurality of pattern cams 2 for imparting a lateral rocking motion to the needles, at least one feed control cam 3 for imparting a feed motion to the feed dog 28, and a plurality of pattern cams 2 and feed control cams 3, respectively. Two cam followers 9, 10 that selectively engage and swing according to the cam shapes of the cams 2, 3, and each of the cam followers 9, 10 corresponds to a desired stitch pattern. a cam selection device including a release cam 16 and a selection cam 19 which are operated to engage the cam, and operable to move the feed dog 28 from an active position to a non-active position for imparting a feed motion to the work cloth; A zigzag sewing machine equipped with a feed dog sinking device, which includes a control cam 50 that rotates in conjunction with the operation of the cam selection device, and a contactor 54 that engages with the control cam 50, and a cam surface of the control cam 50. a linking means for operating the feed dog lowering device according to the shape; and the operation of the feed dog lowering device by the action of the control cam 50 is performed prior to the release movement of the cam followers 9, 10 by the action of the release cam 16; The operating phases of both cams 16 and 50 are set as shown in FIG. A feed dog sinking mechanism characterized in that the cam selection operation is always performed with the feed dog in a depressed state. 2. The control cam 50 has a cam surface that acts to restrain the feed dog lowering device in the operating state when a stitch pattern corresponding to a sewing operation to be performed with the feed dog 28 lowered is selected. A feed dog sinking device in a zigzag sewing machine according to claim 1, which is formed to have a shape.