JPS5923835B2 - Sewing machine stop mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new and useful improvement of a sewing machine, and particularly to an improvement of a stopping mechanism of a sewing machine.

As is well known, sewing machines are provided with a stopping mechanism that allows the sewing machine to coast for a short period of time and then suddenly stop after the main drive shaft is disconnected from the drive pulley.

However, such conventional stop mechanisms typically only rotate about one-half revolution after the clutch is disengaged before the sewing machine stops.

Therefore, the drive shaft is not substantially decelerated during this sudden stop.

The invention is an improved system having two adjusting cams whose relative positions are adjustable and which are related to the other parts such that the main drive shaft makes one to one and a half revolutions before this sudden stop. It attempts to provide a stopping mechanism.

By providing two cams for regulating the operation of such a stop mechanism and by making their relative positions adjustable,
Adjustment to increase or decrease the running time of the drive shaft O is also possible.

This allows adjustments to be made for slight differences in processing and assembly that occur from sewing machine to sewing machine.

The greater deceleration provided by the increased coasting time in the stopping mechanism of the present invention provides the following advantages:

t Damage to parts included in the stop system of the sewing machine is reduced.

2. The noise when the sewing machine stops is reduced.

3. There will be less damage to the sewing machine.

4. Double cycling of the sewing machine is prevented.

Hereinafter, the present invention will be described in detail based on illustrated embodiments.

The improved stop mechanism of the present invention was developed for use in group stitch or cycle sewing machines.

This type of sewing machine is described in U.S. Pat. No. 2,511,36.
No. 7, No. 2,609,773, No. 3,509,838
It is shown in the number etc.

In addition to button sewing machines, this group of sewing machines also includes basting machines of the type shown in U.S. Pat. No. 3,749,041.

In the figure, the sewing machine is designated as a whole by 9 and includes a support 10 having a base part 11 and a sub-base part 12.

A workpiece support arm 13 extends horizontally from the base 11 and is provided with a conventional looper and thread trimmer (not shown).

Above the workpiece support arm 13, a arm 14 projects from the upper end of the support column 10, and a head 15 is provided at the tip of the arm 14.

A needle bar 16 holding a needle 17 is attached to the head 15 so as to move back and forth.

The main shaft 18 is rotatably supported by the base 11,
A conventional drive means for moving the looper and needle during stitching operations such as button attachment is connected to this main shaft.

Since this driving means is not directly related to the present invention, it is not shown in the drawings and its description will be omitted.

As clearly shown in FIG. 1, the main shaft 18 has an eccentric wheel 19 for swinging the member 20 back and forth within an appropriate range each time the main shaft 18 rotates.

During the stitch cycle of the sewing machine, the swinging of the member 20 is idle and does not have any effect.

However, once the sewing machine completes its stitch cycle,
The lower end of the link 21 is moved to the left towards the position shown, so that its shoulder 22 is in the path of the transverse projection 23 of the member 20.

Therefore, when the member 20 swings by the eccentric wheel 19, the link 21 is moved downward.

The upper end of the link 21 is attached to the stud 2 on the overhanging arm 14.
The lever 25 is rotatably coupled to one arm 24 of a lever 25 which is rotatably supported by a lever 25 .

A forwardly extending arm 27 of the lever 25 carries a downwardly extending rod 28, the lower end of which extends laterally and carries a roller 29.

The roller 29 is adapted to cooperate with the underside of a hook-shaped rod 30 fixed to the button clamping mechanism 31.

The button clamp mechanism is described in U.S. Pat.
No. 367, No. 2.609.773 and No. 3,509
, No. 838.

It is rotatably mounted to the sewing machine frame by a rod 32.

The clamp body 31 holds the spring 3 during the stitch cycle.
It is constantly pushed downward by 3.

The rod 28 is lifted upwards and with it the rod 3
0 is also lifted, the clamping mechanism 31 pivots around the rod 32 and attaches the button holder to the workpiece support arm 13.
Pull up from.

During the stitch cycle, the lower end of the link 21 is always held in a position to the right of the position shown in FIG. 1, so that its shoulder 22 is out of the path of the lateral projection 23 of the member 20. .

However, when the sewing machine is at rest, these parts are in the position shown in FIG.

When the sewing machine is started, the lower end of the link 21 moves to the right in FIG.

This is done by the operator operating a foot pedal or knee press that rotates the swing shaft 34 to which the arm 35 is fixed in a counterclockwise direction.

The lower end of arm 35 is rotatably coupled to one end of link 36, and the other end of arm 36 is rotatably coupled to the lower end of link 21.

Just before the selected number of stitches is completed and the sewing machine 75 stops moving, the swing shaft 34 rotates clockwise in FIG. 1, and the link 21 is returned to the position shown in FIG. The shoulder 22 is placed in the path of the lateral projection 23 of the rocker member 20.

The next rotation of the main shaft 18 or the eccentric 19, and therefore the rotation of the rocking member 200, will cause the lateral protrusion 23 to contact the shoulder of the link 21 and drive the link 21 downward.

As a result, the lever 25 rotates counterclockwise and the lot 2
8 engages the rod 30 and lifts the rod 30 together with the button clamp mechanism.

At this time, the sewing machine is automatically stopped.

According to the invention, the sewing machine is equipped with a stop mechanism that is improved from that in the above-mentioned US patent.

As clearly shown in FIGS. 2 and 3, a stop plunger lever 37 is provided on one side of the sewing machine and is fixed to a stop pivot shaft 34.

The plunger lever 37 has a plunger rod 38 which also has a left end (FIG. 3).
It has a stop plunger 39 at the end.

A series of spring washers 40 attach to plunger rod 38.
3, pushing the stop plunger 39 to the left in FIG.

The plunger lever has a lever 41 with a
A cam surface 41a for operating a normal friction clutch for connecting the main shaft 18 to the drive pulley 42 is provided at the free end of the shaft 41.
is formed (Figure 2).

The friction clutch includes a friction plate fixed to a stop disk 43, which is also fixed to the main shaft 18.

The disc 43 is used as a stop plunger 39 when stopping the sewing machine.
It is provided with a pawl 44 and a latch 45 which cooperate with the same.

The plunger 39 is pressed against the stop disk 43 by a spring 46 which is fixed at one end to the plunger lever 37 and at the other end to the frame of the sewing machine.

As best seen in FIGS. 1 and 2, a lever 47 having a cam follower 48 is secured to the end of the pivot shaft 34 opposite the stop plunger lever 37.

The cam follower 48 is positioned so as to be in contact with the edge surfaces of cam disks 49 and 50 attached to the camshaft 51.

The cam disk 49 is attached to the gear 53 by press fitting.

The cam disk 50 is loosely fitted into the knob 52 and has a knob 54.

The cam discs 49 and 50 are connected to the screw hole of the plate 54.
It is fixed to the camshaft 51 by a screw 55 passing through a long hole 56 of the tab 52.

5γ, which is a part of the cam disc 49, is a part of the cam disc 49.
Form an appropriate interval between 9 and 50.

The adjustment lever 58 is inserted between the cam disks 49 and 50, and one end thereof is rotatably attached to the cam disk 50 by a screw 59.

The elongated hole 59a extending in the circumferential direction of the cam disk 490 has a clearance with respect to the shoulder screw 59 so that it can be easily approached.

The other end of the shoe 58 has two holes 61.6 in the cam disk 500.
It is fixed in one of two positions by a shoulder screw 60 that passes selectively through one of 1a.

The cam disk 49 has two notches 62 and 63 on its circumference.

The notch 62 is formed by step portions 64 and 65.
3 is formed by step portions 66 and 67.

Notches 62 and 63 can be easily seen from Figures 4 and 5.
The step portions 64 and 66 are deeper than the step portions 65 and 67.

The cam disk 50 has cutouts 68 and 69 of the same shape, but different in shape from the cutouts 62 and 63, on the same diameter and on opposite sides.

The notches 68 and 69 are shaped so that they line up with the notches 62 and 63 when attached to the camshaft 51.

The diameters of the cam discs 49 and 50 are the same, and when the cam follower 48 rides on the circumference of these cam discs with respect to the lever 47, the swing shaft 34 separates the plunger 39 from the stop disc 43. The relationship is such that they come to each other's positions.

When the shoe 58 is in the position shown in FIGS. 3 and 5, the shoe covers the notch 63 and the machine runs through a full cycle to sew 16 stitches before stopping.

This allows the 4-hole button to be sewn. For example, when it is desired to sew a two-hole button, the shoe is lifted and secured to the cam disk by passing screw 60 through hole 61a.

When the shoe is in this position, the notch 63 is open and the sewing machine is stopped every eight stitch cycles.

When the sewing machine is at rest, the stop plunger lever 37 and the cam discs 49, 50 are in the position shown in FIGS. 1 and 3.

To start the sewing machine, the operator steps on a foot pedal (not shown) connected by a chain 70 to a lever 70a rotatably supported by a bracket 71 on the subpace 12 of the sewing machine.

The lever 70a rotates counterclockwise, and the stand 72 held by the lever 70a moves the downward arm 7 of the plunger lever 37.
3 and rotate the plunger lever clockwise,
The engagement of the plunger 39 with the stop disk 43 is released.

At the same time, the cam surface of the lever 41 acts on the pulley 42 to engage the clutch, whereby the pulley 42 is connected to the main drive shaft 18 and transmits 180 rotations of the drive shaft.

As can be seen in FIG. 1, when the lever 47 is rotated counterclockwise, the cam follower 48 is moved into the notch in the cam disk 49.
It comes off from the lower step part 64 of 2.

The sewing machine then begins a stitch cycle and the cam follower rides up around the circumference of cam discs 49 and 50.

When the camshaft 51 is driven clockwise by a suitable transmission in the sewing machine base, the cam discs 49 and 50 rotate at a rate of 1 revolution for every 166 revolutions of the main drive shaft 18.

The sewing machine continues to be driven by the pulley 42 until the notch 62 in the cam disk 49 approaches the cam follower 48.

Eventually, the cam follower 48 drops into the step 65 of the cam disk 490 from the corner of the cam disk 49,50.

This slight drop causes the swing shaft 34 to rotate clockwise.

As shown in FIG. 3, the stop plunger lever 3
7 is rotated slightly counterclockwise, moving the plunger 39 towards the stop disc 43.

Lever 41 is rotated sufficiently to cause its cam surface to disengage pulley 42 from clutch and main drive shaft 18 of the sewing machine.

At this time, the sewing machine will
There are one and a half revolutions left.

When the sewing machine comes off the pulley 42, it rotates due to inertia and stops.

The position of the plunger 39 at this time is still sufficiently far from the stop plate 43, and the pawl 44 and latch 45 pass through the plunger 39 in the clockwise direction.

Referring again to FIG. 1, as the cam discs 49 and 50 continue to rotate, the cam follower 48 drops from the step 65 into the lower step 64 of the notch 62.

This also causes plunger lever 37 and plunger 39 to fall to their final rest position.

At this time, the stop disk 43 is connected to the pawl 44 and the latch 45.
Approximately half a rotation remains until the sewing machine cooperates with the plunger 39 to stop the sewing machine.

At this time, as mentioned above, the button clamp mechanism 3
1 is lifted from the workpiece support arm 13 so that the operator can remove the already sewn button and insert a new button for the next stitch.

An advantage of this invention is that the coasting time at the end of the stitch cycle does not have to be increased, but rather that this time can be adjusted.

This is done by adjusting the relationship between cam discs 50 and 49.

The cam disk 50 is provided with a circumferential elongated hole 80, as shown in FIGS. 4 and 5.

The screw 81 is screwed into a tapped hole 83 of the cam disk 49 through the elongated hole 80 and the spacing collar 82.

This screw 81 serves to clamp the cam disk 50 to the cam disk 49.

The screw 55 also serves to clamp the cam disks 49 and 50 to each other and to fix them to the camshaft 51.

To adjust the position of the cam discs 49 and 50 relative to the camshaft 51, it is only necessary to loosen the screw 55.

Screw 81 is held tight to maintain the relative position of cam discs 49 and 50.

To adjust the relative position of cam discs 49 and 50, screw 81 is loosened together with screw 55.

By adjusting the cam disk 50 relative to the cam disk 49, the distance D (FIG. 5) can be increased or decreased as desired.

In FIG. 5, cam disk 50 is shown in its maximum counterclockwise rotated position.

In that case, the distance is set to a minimum.

In an actual sewing machine, the cam disk 50 is located approximately in the middle of its adjustment range, and the following discussion regarding adjustment of the relative positions of the cam disks 49 and 50 also assumes that the cam disk 50 is in the middle position.

By rotating the cam disk 50 clockwise, the distance increases, and by rotating it in the opposite direction, the distance decreases.

As the distance increases, the cam follower drops into step 65 sooner, thereby increasing the coasting time of the sewing machine at the end of the stitch cycle.

As a result, the speed at which the sewing machine stops becomes slower than the preset speed.

Similarly, by rotating cam disk 50 in the opposite direction relative to cam disk 49, the coasting time of the sewing machine is reduced and the speed at which the sewing machine comes to a stop is greater than the preset speed.

In the illustrated configuration, the coasting time of the sewing machine at the end of a stitch cycle can be adjusted to one to one and a half revolutions.

When the cam disk 50 rotates, the shaft 58 also rotates.

When replacing the shoe 58, no matter what positional relationship the cam disk 50 has with respect to the cam disk 49, the elongated hole 59a
The screw 59 can be accessed from the outside.

Of course, in order to replace the shoe 58, the cam disc 4
9 and 50 from the camshaft 51.

As is clear from the above, differences in coasting time due to errors in manufacturing and assembly of parts of the sewing machine are caused by
This can be easily adjusted by adjusting the relative positions of and 50.

For example, if after assembly it is found that one sewing machine has a higher frictional force than another, then this sewing machine is adjusted to have a shorter coasting time than other sewing machines with lower frictional forces.

Also, when parts worn out by -1 are replaced, the coasting time is readjusted.

What has been illustrated and described above is merely one embodiment of the invention, and without departing from the spirit of the invention,
Of course, various modifications can be made.

Note that effective embodiments of the present invention will be summarized below.

(1) In the claims, the first
The step part is lengthened in the circumferential direction, and adjustment means is provided to support the cam follower along an appropriate portion of the first step part, and the effective length of the first step part is varied to enable the clutch to operate. A sewing machine stop mechanism that changes the time it takes for the main drive shaft to stop after it comes off.

(2) In the item described in item 1 above, the adjusting means has a second adjusting step portion located between both ends of the first step portion.
A sewing machine stop mechanism with a cam.

(3) In the device described in item 2 above, means is provided for supporting the second cam so that it can rotate with respect to the first cam, and means for locking both cams together at an arbitrary angular position. A sewing machine stop mechanism equipped with a

(4) A stopping mechanism for a sewing machine according to item 3 above, wherein both cams have concentric inserts forming part of the support means.

(9) in accordance with paragraph 3 above, wherein both said cams have concentric insert tabs forming part of the support means and are attached to the outer bub of said A stop mechanism for a sewing machine having screw means through which one of the cams is secured to the camshaft.

(6) In the device described in item 2 above, each of the cams has a plurality of steps, and cooperates with at least some of these steps to selectively bring the cooperating steps into an inactive state. A stopping mechanism for a sewing machine having a blocking means for stopping the sewing machine.

(7) The stopping mechanism for a sewing machine according to item 6 above, wherein the blocking means is a shoe sandwiched between two cams.

(8) In the device described in item 6 above, the blocking means is a shoe sandwiched between two cams, and one end of the shoe is rotatably supported, and the other end is operated or operated by the cam step. A sewing machine stop mechanism provided with means for selectively positioning it into an inoperative state.

(9) In the claimed invention, the cam has a plurality of steps, and cooperates with at least some of the steps to selectively put the cooperating steps in an inactive state. A stopping mechanism for a sewing machine having a blocking means for stopping the sewing machine.

(10) In the device described in the claims, the main drive shaft and the camshaft are parallel, and the first and second lever means and the swing lever are arranged parallel to the main drive shaft and the camshaft. A sewing machine stop mechanism supported by a third shaft.

[Brief explanation of the drawing]

The figure shows an embodiment of the invention. FIG. 1 is a partially cutaway side view of a sewing machine equipped with a stop mechanism according to the present invention. FIG. 2 is a partially cutaway plan view of FIG. 1. FIG. 3 is a partially cutaway partial side view showing the side opposite to FIG. 1. FIG. 4 is an exploded, enlarged perspective view of the stop cam assembly. FIG. 5 is an enlarged front view of the stop cam assembly. FIG. 6 is a sectional view taken along line 6-6 in FIG. 18... Main drive shaft, 37... Second lever, 41-
...First lever, 42...Drive pulley, 43...
Stop disk, 47... Swinging lever, 48-- Cam follower, 49-- Cam, 51... Cam shaft, 64... Second step, 65... First Danbe.

Claims (1)

[Scope of Claims] 1. A main drive shaft, a drive pulley, a clutch that selectively connects the main drive shaft to the drive pulley to drive the drive pulley, and a stop disk supported on the main drive shaft. and a first lever means for controlling the operation of the clutch, and a second lever means for stopping the main drive shaft and preventing its rotation in cooperation with the stop disk. In the stopping mechanism, a swinging device is provided for swinging the first and second lever means together, and the swinging device includes a camshaft driven to reduce speed by the main drive shaft, and the cam. a cam rotatably carried on a shaft and having a reference surface and adjacent first and second radial steps; a swinging lever connected to one means; and a cam follower supported by the swinging lever and riding on the cam reference surface and subsequently engaging the stepped portion, the cam follower being connected to the first means. When engaged with the step, the first and second levers pivot a distance sufficient to disengage the clutch, but insufficient to engage the stop disc, and the cam follower rotates a distance sufficient to disengage the clutch, but insufficient to engage the stop disc. The first and second step portions of the cam are aligned with the reference plane so that when engaged with the step portion of the cam, the first and second levers rotate by a distance that engages and stops the stop disk. A sewing machine stop mechanism that is spaced radially from 2. The effective length of the first step is increased by lengthening the first step of the cam in the circumferential direction and by providing adjustment means for supporting the cam follower along a selected portion of the first step. 2. The stopping mechanism for a sewing machine according to claim 1, wherein the time from when the clutch is disengaged until the main drive shaft stops is changed by changing the time. 3. A patent claim in which the cam has a plurality of sets of steps and is provided with a blocking means that cooperates with at least some sets of the steps to selectively render the cooperating steps inoperative. The stopping mechanism of the sewing machine according to item 1.