JPH0135721Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention relates to a pattern generation mechanism in a zigzag sewing machine, and in particular a first pattern cam that is linked to a drive shaft and rotates at a reduced speed, and an elongator cam that can adjust the elongator. The present invention relates to a pattern generation mechanism by engagement of a second cam follower.

(Prior art) In conventional zigzag sewing machines, the approximate size of the sewing machine casing is determined, so the space inside the sewing machine casing is limited, and therefore the cam for pattern generation is either replaceable or Even with the built-in type, the size of the cam, especially the diameter, is limited, and the design must take into account the cam lift and pressing angle so that the cam follower can swing. The number of times the rod is swung during rotation is naturally limited, and the number of stitches in one cycle of the pattern cannot be increased freely;
The majority had a reduction ratio of 18.

(Problem that the invention aims to solve) In recent years, it has become desirable to make patterns such as satin and scallops larger, so a 1/36 reduction cam is partially incorporated to reduce the size of patterns such as satin and scallops. It formed a cycle of 36 needle patterns,
As mentioned above, the cam lift corresponding to the pressure of the cam follower was limited, and it was difficult to swing the needle over the full width of the zigzag sewing machine (for example, 7 mm), so the patterns that could be produced were also limited. In contrast, the purpose of the present invention is to obtain patterns of many sizes by swinging the needle over the entire width of the elongator pattern whose pattern length can be freely adjusted.

(Means for Solving the Problem) In the present invention, the elongator actuating pawl that follows the elongator actuating cam provided coaxially with the first pattern cam rotating at a conventional reduction ratio and in a part of the first pattern cam group is used to intermittently A second elongator cam to be driven is provided, and a means for engaging the first follower with a second follower that follows the second pattern cam is provided on the first follower. In addition to the conventional zigzag pattern using only cams, the first cam follower and second cam follower are engaged with their respective pattern cams to combine the patterns, allowing full width to be used for large elongator patterns. This will give you a similar pattern.

(Example) An example of the present invention will be described in detail with reference to the drawings.
In Fig. 1, 1 is a sewing machine frame, 2 and 3 are mechanism frames that are fixed inside the sewing machine frame and stand upright in parallel in the front and back, and 4 and 5 are fixed to the mechanism frame, respectively. 6 is the mechanism frame 2.
The selection shaft is rotatably supported by the

7 is a drive shaft rotatably supported on the sewing machine frame 1; a worm 8 is fixed to the drive shaft 7; and a worm gear 9 in which the worm 8 is rotatably supported on the fixed shaft 4. It meshes with the 10
is a first pattern cam with a reduction ratio of 1/18, which is rotatably supported on the fixed shaft 4 and whose rotation is transmitted by the pin 9a of the worm gear 9.

Positioned on the fixed shaft 4 by an E ring 27 that is aligned with the first pattern cam 10 and whose thrust fits into a groove provided in the fixed shaft 4, and a wave washer 28 that contacts the mechanism base plate 3, A second pattern cam 11 that can change the reduction ratio as appropriate is fitted. A clutch roller 29, a clutch spring 30, and a clutch ring 31 are attached to the bushing portion 11a of the second pattern cam 11. Reference numeral 13 denotes a pattern selection operation section, which is fixed to the selection shaft 6. A feed release cam 14 having a gear portion 14a is fixed to the selection shaft 6, and the rotation of the follower release cam 1 is transmitted through a pin 15 fixed to the tip of the selection shaft 6.
6 is fitted. Reference numeral 17 designates a pattern cam selection cam, which is rotatably pivoted to a shaft portion 18 fixed to the mechanism frame 2, and its toothed portion 17a meshes with the toothed portion 14a of the feed release cam 14. A swing arm 19, a first follower 20, a second follower 21, a follower spring 22, and a swing release arm 23 are attached to the fixed shaft 5, respectively.

The groove 19b of the swinging arm 19 and the protrusion 20b of the first follower 20 are engaged with each other, and the first
The movement of the first follower 20 that engages with the pattern cam 10 is transmitted to the swinging arm 19, and the arm portion 19a of the swinging arm 19 is connected to a needle bar support that swings the needle. It engages a swinging rod (none of which is shown).

The second follower 21 includes the follower spring 22 and a slide stopper 19 provided on the swinging arm 19.
The axial position is limited by c and further positioned by the boss of the first follower 20. The rotation direction is biased counterclockwise by the action of the spring 24 and follows the second pattern cam 11. Reference numeral 25 denotes a swinging claw slide plate, which is biased by a spring 41 to move the claw portion 2
5b is engaged with the cam portion 17b of the selection cam 17, and the forked portion 25a is fitted into the groove of the boss of the first follower 20, thereby changing the position of the first follower 20. is controlled by the selection cam 17.

The swing width release arm 23 is biased counterclockwise by a spring 26, and its claw portion 23a engages with the follower release cam 16. A dial shaft 3 rotatably supported on the mechanism base plates 2 and 3.
Elongator dial 3 via wave washer 34 to 2
3 is fixed. Further, an adjusting arm 35 is fixed to the dial with a screw 36. The shaft portion 38a of the elongator operating pawl 38 is fitted into the boss 37 fixed to the mechanism base plate 3 and thrusted by an E-ring, and the pawl portion 38b is pushed by a spring 39 into a portion of the first pattern cam. The elongator actuating cam 10c is engaged with the elongator actuating cam 10c provided in the. A pin 40a of a rod 40, one end of which is secured to a pin 31a provided on the clutch ring arm, is loosely fitted into the arcuate groove 38c of the elongator operating pawl 38.
An adjustment rod 12 connected to the adjustment arm 35 is plugged into the adjustment arm 35.

Next, the operation will be explained. The drive shaft 7 rotates in the direction of arrow A in FIG.
The first pattern cam 10 is rotated in the direction of arrow B at a reduction ratio of 1/18. The first pattern cam 10
In contrast, the position of the first follower 20 is set as follows. By rotating the selection dial 13 fixed to the selection shaft 6, the follower release cam 16 fixed to the selection shaft 6 is rotated, and the swinging width release arm 23 that is engaged with it is rotated in the direction of the arrow C. The screw tip 23b fixed to the bent portion 23a is connected to the swinging arm 1.
9 and rotates the swinging arm 19 clockwise, thereby causing the first follower 20 having a convex portion 20b that engages with the long groove 19b of the swinging arm 19 to move into the first pattern. The second follower 21, which is engaged with the lower surface 19d (FIG. 3) of the swinging arm 19, also disengages from the second pattern cam 11. . On the other hand, as the selection shaft 6 rotates, the fixed feed release cam 14 also rotates, and the selection cam 17 that engages with its teeth 14a rotates, causing the swinging claw slide plate 25 to come into contact with the cam surface 17b. is moved in the axial direction, and the first follower 20 is moved by the forked portion 25a. This series of operations is carried out by the follower release cam 16 and the selection cam 17, so that the cam 1 of the first pattern cam 10
It is configured to sequentially release the first and second followers, move the first follower, and engage the first and second followers for each sheet.

When the first follower 20 is set to the position R in FIG. 2 by operating the selection dial 13, it is engaged with the first pattern cam 10a and is driven at a reduction ratio of 1/18. Convex portion 20b of follower 20 of No. 1
The signal is transmitted through the groove 19b of the swinging arm 19 that engages with the swinging rod to move the swinging rod to draw a normal pattern with a reduction ratio of 1/18 as shown in FIG. 6.

At this time, the second follower 21 is biased by the spring 22 and positioned on the protrusion 19c of the swinging arm 19 and engaged with the second pattern cam 11, but the first follower 21 Only the child 20 is engaged with the swinging arm 19. Next, when the first follower 20 is set to the position S in FIG. 2 by rotating the selection dial 13, that is, the first follower 20 is set to the first
When engaging the pattern cam 10b, the bent portion 20a
The screw tip 20d fixed to is located on the back surface of the second follower 21 (FIG. 3). In this case, the first pattern cam 10b rotates at a reduction ratio of 1/18, and the stitch locus created only by this cam is 1, 2, 3 as shown in FIG.
~18, which is a normal zigzag cam that closely zigzags the width of the swinging width. The second pattern cam 11b is a pattern cam that increases and decreases linearly, and the third pattern cam 11b is a pattern cam that increases and decreases linearly.
As shown in the figure, the second follower 21 engages with the second pattern cam 11b and the first follower 20
The screw tip 20d provided in the second follower 21c
The first follower 20 is abutted against and engaged with the back surface of the second follower 20 to restrict movement of the first follower 20 toward the valley side.

Next, the driving state of the second pattern cam 11 will be explained. In FIG. 4, the elongator operating claw 38 is engaged with the peak of the elongator operating cam 10c provided on the first pattern cam 10, and at this time the first follower 20 is It is located at a position where it engages with the first pattern cam 10b, which is a zigzag cam, and is set to be the starting position of the equal diameter portion of the valley portion of the first pattern cam 10b, which is indicated by the dotted line in the figure. In the figure, as shown by the solid line, the screw tip 20d of the first follower 20 comes into contact with the back surface of the second follower 21 that engages with the second pattern cam 11, and the first follower 20 Although it is in a position where it does not engage with the pattern cam 10b, the second
The following description will omit the engagement with the follower 21.

Next, the drive shaft 7 rotates, thereby causing the elongator operating cam 10c to rotate in the direction of the arrow B. When the elongator pawl 38 advances to the trough of the elongator operating cam 10c as shown in FIG. 5, the spring 39
Due to this action, the clutch ring 31 is pulled in the direction of the solid arrow and rotates clockwise, but the clutch roller 29 is caused to idle due to the frictional action of the wave washer 28 that comes into contact with the end surface of the bushing portion 11a of the second pattern cam 11. However, the second pattern cam 11 remains stationary. During the angle θ ₁ from the peak to the valley of this elongator operating cam 10c, the second pattern cam 1
1 is stationary, and at this time the first pattern cam 1
0b, the first follower 20 engages with the first follower 20.
It follows the angle θ ₂ of the equal diameter part on the valley side of the pattern cam 10b, and there is no rotation due to the cam action. The angle θ ₁ on the elongator operating cam 10c side and the angle θ ₂ on the first pattern cam 10b side are set to be the same and in phase. Next, when the elongator operating claw 38 advances from the trough to the peak of the elongator operating cam 10c, the spring 39
The clutch ring 31 is rotated in the direction indicated by the dotted line in the figure, and the clutch roller 29 is moved between the clutch ring 31 and the boss portion 1 of the second pattern cam 11.
1a, the movement of the elongator actuating claw 38 is transmitted to the second pattern cam 11 and rotates counterclockwise, causing the second follower 21 engaged therewith to rotate. At this time, the first follower 20 moves from the valley to the peak of the first pattern cam 10b, and C
Rotate in the direction of the arrow. This second pattern cam 11
The elongator operating cam and the first pattern cam 10b are set in advance so that the rotational phase of the first follower 20 and the rotational phase of the first follower 20 are synchronized.

Next, when the elongator operating claw 38 moves from the peak to the valley of the elongator operating cam 10c, the clutch roller 29 idles as described above,
The second pattern cam 11 remains stationary. At this time, the first
The follower 20 advances from the equal diameter portion of the peak of the first pattern cam 10b, and the first follower 20 does not rotate.

In this way, the second pattern cam 11 is intermittently rotated via the clutch ring 31 by the action of the elongator operating cam 10c and the elongator operating claw 38 one after another.

The second pattern cam 11b is engaged with the second pattern cam 11b.
The second follower 21 follows, but the second follower rotates synchronously only when the first follower rotates, as described above.

Regarding pattern generation, the screw tip 20d of the first follower 20 is located on the back surface of the second follower 21, and the valley of the stitch locus (FIG. 6 1) of the first pattern cam 10b is located. The movement of the first follower to the side is restricted by the second follower 21 following the second pattern cam 11b, resulting in a seam as shown in FIG. 6 and 3.

Next, the adjustment of the elongator will be explained. The state shown by the solid line in FIG. 4 is the elongator dial 33.
The adjustment ranges are medium, large, medium, and small, and the distance between the center of the pin portion 40a of the rod 40 and the center of swing of the elongator operating claw 38 is _L2 . Next, as shown by the two-dot chain line, when the elongator dial 33 is rotated clockwise to increase the length, the distance is shortened to _L1 .

As a result, the intermittent rotation angle of the second pattern cam 11 is reduced, and the degree of linear increase/decrease by the second pattern cam 11 becomes gentle, so that the composite pattern has a pattern size as shown in FIG. becomes larger.

Conversely, by rotating the elongator dial 33 counterclockwise to make it smaller, the distance described above can be reduced.
L ₃ and long. As a result, the second pattern cam 11
The intermittent rotation angle increases, the degree of linear increase/decrease by the second pattern cam 11b becomes severe, and the size of the composite pattern becomes smaller as shown in FIG. 6-2.

(Effect of the invention) With the above configuration, in addition to the conventional selection of sewing patterns based on the reduction ratio by operating the pattern selection dial as in the invention, it is possible to select a pattern in which the elongator can be adjusted while keeping the swing width full. . The elongator can be easily and steplessly adjusted using a separate dial, and can be adjusted without changing the conventional sewing pattern of the reduction ratio mentioned above, making it possible to adjust the elongator for large sizes with a large number of stitches, such as scallops and satin. It is possible to provide a pattern.

[Brief explanation of the drawing]

The drawings relate to an embodiment of the present invention, and FIG. 1 is a perspective view of the mechanism, FIG. 2 is a diagram showing the cam follower engaged state, FIG. 3 is a side view thereof, and FIGS. 4 and 5 are views of the elongator state. The explanatory diagram, FIG. 6, shows the pattern stitches, 1 is the sewing machine frame, 7 is the drive shaft, 10 is the first pattern cam, 11 is the second pattern cam, 13 is the pattern selection section,
20 is a first cam follower, 21 is a second cam follower, 10a is an elongator operating cam, and 38 is an elongator operating claw.

Claims (1)

[Claims for Utility Model Registration] (1) A drive shaft rotatably supported within the sewing machine frame, and a cam follower whose one end is removably supported on the outer periphery of a pattern cam that is linked to the rotation of the drive shaft. With a child
In a sewing machine equipped with a needle bar supporter which is caused to swing in a width direction via a connecting rod when one end of the cam follower is engaged with the pattern cam, 1
a pattern cam, a second pattern cam is mounted coaxially with the first pattern cam, and a first cam follower that is engaged with and disengaged from the first pattern cam by operation of a pattern selection section; A second cam follower that is engaged with and disengaged from the second pattern cam, and an engaging portion for engaging the first cam follower and the second cam follower. The pattern generation mechanism of a zigzag sewing machine. (2) The driving means for the second pattern cam includes an elongator actuating pawl that is driven by an elongator actuating cam provided on the first pattern cam, and a rotation of the elongator actuating pawl intermittently drives the second pattern cam. Claim 1 of the Utility Model Registration Claim further comprising: an engaging/disengaging means for driving the elongator, and an adjusting means for adjusting the amount of rotation of the second pattern cam by changing the rotation angle of the elongator operating claw. The pattern generation mechanism of the zigzag sewing machine.