JPS6012521Y2 - Upper feed device of sewing machine - Google Patents

Description

[Detailed explanation of the idea] Technical field This invention relates to an upper feed device for a sewing machine.

In a conventional upper feed device of a sewing machine, an upper feed dog disposed above a workpiece cloth performs a four-feed motion together with a lower feed dog below the workpiece cloth, thereby imparting feed to the workpiece cloth from above.

However, in the conventional upper feed device, the upper feed base supporting the upper feed dog was directly engaged with the feed drive cam.
When the sewing machine is operated at high speed, the upper feed table cannot follow the movement of the cam surface, and the upper feed table continuously moves away from the cam surface or collides with the cam surface.

For this reason, not only impact noise and vibrations are generated, but also there is a risk that the cam surface and the engagement surface of the upper feed table will wear out prematurely.

Therefore, it has been virtually impossible to equip a sewing machine operated at high speed with this conventional top feed device.

Purpose of the invention The purpose of this invention is to eliminate the above-mentioned defects and provide an upper feed device that can be installed in a high-speed sewing machine without causing any problems.

EXAMPLE Hereinafter, an example in which this invention is embodied in an overlock sewing machine will be described based on the drawings.

A horizontal feed eccentric wheel 13 is fixed to a sewing machine main shaft 12 that is supported at the lower part of a sewing machine frame 11 and is actively rotated in one direction by a motor (not shown). It holds the eccentric wheel 13 for use.

In addition, the sewing machine frame 11 includes first to sixth support shafts 15 to 2.
0 are rotatably supported at respective fixed positions.

A feed adjustment member 21 is fixed to the first support shaft 15 at its center, and the eccentric wheel holder 14 is fixed to one end of the feed adjustment member 21.
The tip of the shaft is connected to the shaft.

An adjustment groove 22 is formed at the other end of the feed adjustment member 21 .

A connecting lever 71 and a horizontal feed arm 23 as a second swinging arm are each fixed to the second support shaft 16, and one end of a connecting link 24 is axially connected to the lower end of the connecting lever 71.

A square piece 26 is attached to the other end of this connecting link 24 by a shaft 25.
is attached, and its square piece 26 is aligned with the adjustment groove 22.
is slidably fitted to the

Then, by the feed adjustment member 21 and the square piece 26,
A feed adjuster is configured to adjust the horizontal feed amount of the upper feed dog 38, which will be described later.

An intermediate lever 27 is fixed to the third support shaft 17,
One end of a connecting link 28 is axially connected to its tip.

The other end of this connecting link 28 is connected to the shaft 25 of the square piece 26.

An adjustment lever 29 is fixed to the third support shaft 17,
A stepped screw 30 for tightening is attached near the tip.

A tightening plate 31 is fixed to the sewing machine frame 11, and the tightening is achieved by inserting the stepped screw 30 through a guide hole 1a formed in the plate 31. By tightening the adjustment lever 29 against the plate 31, the adjustment lever 29 can be fixed at any rotational position.

Therefore, when this adjustment lever 29 is rotated, the third support shaft 17 is rotated to the left or right, and the intermediate lever 29 is rotated.
7 and the connecting link 28, the square piece 26 is connected to the adjustment groove 2.
2, and its square piece 26 approaches and moves away from the axis of the first support shaft 15.

Then, by tightening the stepped screw 30, the square piece 2
6 can be fixed in its moving position.

A vertical feed arm 32 as a first swinging arm is fixed to the fourth support shaft 18, and a connecting link 33 as a first link is rotatably connected to the free end of the arm 32 at its lower end. ing.

A horizontal feed link 34 serving as a second link is rotatably connected to the upper end of this connecting link 33 by a shaft 35 at an intermediate portion (see FIG. 5), and one end thereof is connected to the horizontal feed arm 23 by a shaft 36. It is rotatably connected to the upper end (free end) of.

An upper feed table 37 extending in the front-rear direction is rotatably supported on the shaft 35 at an intermediate portion thereof, and an upper feed tooth 38 is fixed to the front end, that is, the end on the work cloth feed side.

Therefore, the connecting link 33 and the horizontal feed link 34 are rotatably connected to the upper feed table 37 by the shaft 35.

Further, the upper feed table 37 and the horizontal feed link 34 are arranged above the workpiece cloth support surface 39 of the sewing machine frame 11, and the upper feed dog 38 makes a four-feed movement through the opening 40a of the throat plate 40. It faces the lower feed dog 41.

When the main shaft 12 of the sewing machine is rotated, the horizontal feed eccentric wheel 13 rotates, and the feed adjustment member 21 is swung left and right via the eccentric wheel holder 14, as shown in FIG.

Therefore, the horizontal feed arm 23 is connected to the second support shaft 16 through the engagement between the adjustment groove 22 and the square piece 26 and the connection link 24.
The upper feed table 37 is reciprocated back and forth via the horizontal feed link 34 and shaft 35.

This causes the upper feed dog 38 to perform a horizontal feed movement.

Therefore, the horizontal feed eccentric 13, the eccentric ring holder 14, the horizontal feed arm 23, and the like constitute a horizontal movement imparting mechanism for imparting horizontal movement to the upper feed table 37.

Further, when the square piece 26 is moved by rotating the adjustment lever 29, the square piece 26 and the first support shaft 15 are moved.
The distance between the horizontal feed arm 23 and the axis is changed, the swing range of the horizontal feed arm 23 is widened or narrowed, and the horizontal feed amount of the upper feed dog 38 is changed and adjusted.

An adjusting screw 4 is provided in the screw hole at the other end of the horizontal feed link 34.
2 is screwed in.

Further, at the rear of the shaft 35, a pressing spring 44 is rotatably supported in the middle of the horizontal feed link 34 by a stepped screw 43 (see FIG. 6). 42 is inserted and fitted, and the rear end is in elastic contact with the lower surface of the upper feed table 37.

Therefore, a spring force is applied to the upper feed table 37 in the clockwise direction in FIG. By changing the amount of insertion of the screw 42, the spring force can be adjusted.

At the rear of the fixed part of the pressing spring 44, a horizontal feed link 3 is installed.
4 is fixed with a screw 45 to a stopper member 46 having an inverted U-shaped cross section, and as shown in FIG. The clockwise rotation of 37 is restricted.

A vertical feed eccentric 47 is fixed to the sewing machine main shaft 12, and an eccentric wheel holder 48 holds the vertical feed eccentric 47 at its base end.

A connecting lever 49 is fixed to the fifth support shaft 19,
Its tip is axially connected to the tip of the eccentric wheel holder 48.

Further, a cutter support lever 50 and a transmission lever 51 are fixed to the fifth support shaft 19, and the support lever 50
A movable cutter 52 is attached to the tip.

Then, due to the rotation of the vertical feed eccentric wheel 47 based on the rotation of the sewing machine main shaft 12, the fifth support shaft 19 is reciprocated within a certain range via the eccentric wheel holder 48.

Therefore, the cutter support lever 50 is swung, the movable cutter 52 is moved up and down, and the movable cutter 52 and the second
In cooperation with the fixed cutter 53 shown in the figure, the edge of the work cloth sent backward is cut.

In addition, 54 indicates a cloth presser foot, 55 indicates an auxiliary feed dog that moves in four feeds through the opening 40a of the throat plate 40, and 56 indicates a sewing machine needle, and the auxiliary feed dog 55 changes the feed amount of the fabric even during sewing. By adjusting, the feed amount can be made larger or smaller than the work cloth feed amount by the upper feed dog 38 and the lower feed dog 41.

A connecting link 57 is connected at one end to the distal end of the transmission lever 51 by a shaft 65, and a stepped pin 58 is rotatably inserted into a hole 57a at the other end as shown in FIG.

Further, a setting lever 59 is fixed to the fourth shaft 18, and the setting lever 759 has an arc-shaped setting groove 5.
9a is provided transparently.

Further, a stepped pin 58 at the tip of the connecting link 57 is inserted into a setting groove 59a, and a nut 60 is screwed onto the threaded portion 58a at the tip of the stepped pin 58. Stepped pin 58 connects to setting groove 59
The distance between the stepped pin 58 and the fourth support shaft 18 can be changed and fixed at the set position by tightening the nut 60.

As shown in FIG. 4, when the fifth shaft 19 is reciprocated by the rotation of the vertical feed eccentric wheel 47 as the sewing machine main shaft 12 rotates, the transmission lever 51 is swung, and the connecting link The setting lever 59 is also swung together with the fourth support shaft 18 via the setting lever 57 .

Therefore, as shown in FIGS. 8 and 9, the vertical feed arm 3
2 is swung up and down, and a vertical movement is applied to the upper feed table 37 via the connecting link 33 and the shaft 35.

In this case, a clockwise rotation force is applied to the upper feed table 37 by a pressing spring 44, and a downward force is applied to the upper feed dog 381, but the clockwise rotation is prevented by a stopper. Since it is blocked by one member 46, even if the upper feed bar 37 is given a vertical motion and the shaft 35 portion rises, the upper feed bar 37 rotates clockwise and the upper feed dog 38 descends. Never.

Therefore, the upper feed dog 38 is moved up and down as the connecting link 33 moves up and down.

Further, as shown in FIG. 8, when the transmission lever 51 swings so that the upper feed dog 38 comes to the lowered position, the setting groove 59a is centered around the axis of the shaft 65 of the transmission lever 51. It follows an arc.

In this way, the vertical feed eccentric 47, the eccentric wheel holder 48,
The connection lever 49, the connection link 57, the setting lever 59, etc. constitute a vertical motion imparting mechanism, and as will become clear from the explanation below, the connection lever 49, the setting lever 59, etc. keep the lower position of the upper feed dog 38 constant. A vertical movement adjusting means is configured to change the amount of rise of the upper feed dog 38 only upward with reference to the position.

Note that the stopper member 46 may be provided on the connecting link 33, and in short, it is sufficient as long as it prevents the upper feed table 37 from rotating clockwise when the upper feed table 37 is raised. .

A push-down rod 62 biased upward by a spring 61 is arranged at the rear of the sewing machine frame 11.

Further, a presser foot lifting lever 63 and a connecting lever 64 are fixed to the sixth support shaft 20, and the upper end of the pressing rod 62 is engaged with the lower surface of the tip of the presser foot lifting lever 63.

When the presser foot lifting pedal (not shown) is depressed, the connecting lever 64 is rotated counterclockwise in FIG.
Therefore, the presser foot lifting lever 63 is rotated counterclockwise in FIG. The feed bar 37 is rotated counterclockwise in FIG. 1 about the shaft 35, and the upper feed dog 38 is moved to the upper retracted position.

Now, FIG. 1 shows a state in which the upper feed dog 38 is in the lowered position.

When the sewing machine is operated in this state and the sewing machine main shaft 12 is rotated, the horizontal feed eccentric wheel 13 and the vertical feed eccentric wheel 47 move the upper feed table 37 horizontally and vertically, respectively, as described above. The motions are applied and these motions are synthesized, and as shown in FIG. 10, the upper feed dog 3
8 performs four-movement forwarding.

In this case, in this upper feed device, the transmission paths from the horizontal feed eccentric 13 and the vertical feed eccentric 47 to the upper feed table 37 are all constituted by links and lever mechanisms, so the upper feed table is connected to the cam. Unlike conventional upper feed devices that are directly engaged with the sewing machine, there is no collision noise or vibration even when the sewing machine is operated at high speed, and smooth fabric feeding can be achieved.

Furthermore, if the work cloth is thick, it is necessary to move the raised position of the upper feed dog 38 upward to ensure that the upper feed dog 38 is separated from the work cloth when it is raised.

In this case, do as follows.

First, the sewing machine is stopped and the upper feed dog 38 is placed in the lowered position.

In this way, the setting groove 59a of the setting lever 59 is located on an arc centered on the shaft 65 of the transmission lever 51, so that the connecting link 57 is centered on the shaft 65 of the setting lever 59.
It will be possible to rotate independently regardless of 9.

In other words, even if the connecting link 57 is rotated, the upper feed dog 38 continues to be held in the lowered position.

Therefore, in this state, the nut 60 at the tip of the connecting link 57
, release the fixation of the nut 60 to the setting lever 59, release the connection of the connecting link 57 to the setting lever 59, rotate the connecting link 57 downward, and tighten the nut 60 again at that rotation position to connect. lever 57
is connected to the setting lever 59.

In this way, the distance between the stepped pin 58 and the fourth shaft 18 is shortened, so that when the transmission lever 51 is swung while the sewing machine is operating, the setting lever 59, that is, the vertical feed arm 32 is swung. The amount of movement becomes larger than before the connection position of the connecting link 57 was changed, and the amount of rise of the upper feed dog 38 becomes larger.

However, the connecting link 57 to the setting lever 59
Since the transmission lever 51 is not rotated when the coupling position is changed, the lowering position of the upper feed dog 38 when there is no work cloth is not changed, and as a result, the upper feed dog 38 is moved as shown by the two-dot chain line A in FIG. In this way, a four-feed motion locus is obtained in which the descending position is constant and the ascending amount is changed only upward with respect to the descending position as a reference.

Therefore, even when the workpiece cloth is thick, the upper feed dog 38 can reliably separate from the workpiece cloth during the return movement, without adversely affecting the cloth feed.

Moreover, since the lowering position of the upper feed dog 38 when there is no work cloth is not changed, when feeding a thick work cloth, the upper feed dog 38 is raised according to the thickness.
The spring of the presser spring 44 applied to the upper feed dog 38 becomes larger, the pressure of the cloth presser increases, and the thick work cloth can be reliably fed in cooperation with the lower feed dog 41.

In addition, if the work cloth is thin, when the upper feed dog 38 is in the lowered position, the connecting link 57 is rotated upward in the opposite manner to the above and fixed at that position, as shown by the two-dot chain line B in Fig. 10. As shown, the amount of rise of the upper feed dog 38 that corresponds to the thin work cloth can be obtained.

Moreover, since the cloth thickness is reduced without changing the lowering position, the cloth presser pressure exerted by the upper feed dog 38 becomes weaker, and tearing of the workpiece cloth can be reliably prevented.

The amount of horizontal movement of the upper feed dog 38 can be adjusted using the adjustment lever 2.
9.

Next, another embodiment of this invention will be described based on FIG. 11.

In this embodiment, the press spring 44 is fixed to the horizontal feed link 34 with a screw 66, the front protrusion of the press spring 44 and the horizontal feed link 34 is omitted, and the upper feed base 37 is
The spring force applied by the pressing spring 44 is always constant.

Further, in the sewing machine frame 11, a pressure rod 68 which is in contact with the upper surface of the upper feed table 37 near the front end is supported in a lower end roller 67 so as to be movable up and down.
A spring 69 is provided which biases toward the direction 7, and further,
A threaded rod 70 for adjusting the repulsive force of the spring 69 is supported on the sewing machine frame 11.

Therefore, the pressing force applied to the upper feed dog 38 is applied by the pressing spring 4.
4 and a spring 69, and the pressing force is adjusted by changing the amount of compression of the spring 69 based on the rotating operation of the threaded rod 70.

Effects of the Invention As exemplified in the embodiments above, this invention has a first swing arm between the upper feed table having the upper feed dog and the first swing arm that swings in the vertical direction in conjunction with the main shaft of the sewing machine. In addition, a second link is provided between the upper feed table and a second swing arm that swings in the horizontal direction in conjunction with the main shaft of the sewing machine, and By providing a spring to apply downward pressure and a stopper member to restrict the rotation of the upper feed table due to the action of the spring when the upper feed dog is raised, the sewing machine can be operated at high speed. It exhibits an excellent effect of being able to smoothly feed the cloth without producing any impact noise or vibration even when operated at high speeds.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an upper feeding device embodying this invention, Fig. 2 is a plan view thereof, Fig. 3 is a side sectional view showing a horizontal movement imparting mechanism, and Fig. 4 is a vertical movement imparting mechanism. A side sectional view, FIG. 5 is a sectional view showing the lever on the fourth support shaft, FIG. 6 is a sectional view showing how the presser spring is attached, and FIG. 7 is an enlarged sectional view showing how the stopper member is attached. , Figures 8 and 9 are partial side views showing when the upper feed dog is in the lowered position and the raised position respectively, Figure 10 is a line diagram showing the four-movement feed of the upper feed dog, and Figure 11 is this diagram. FIG. 7 is a side view showing another embodiment of the invention. Sewing machine main shaft...12, horizontal feed arm...
23. Vertical feed arm...32. Connecting link...
...33, Horizontal feed link...34, Upper feed table...37, Upper feed dog...3B, Work cloth support surface...39 , lower feed dog...41,
If you press it...44, stopper part...
・46°

Claims (1)

[Scope of Claim for Utility Model Registration] 1. An upper feed table 37 which is disposed on a work cloth support surface 39 and has an upper feed dog 38 attached to the work cloth feed side that cooperates with a lower feed dog 41, and the main shaft 12 of the sewing machine. a first swinging arm 32 that swings in the vertical direction in conjunction with the first swinging arm 32; one end is rotatably connected to the free end of the first swinging arm 32, and the other end is connected to the upper feed base 37 a first link 33 that is rotatably connected to the workpiece cloth delivery side of the work cloth and is configured to provide vertical movement to the upper feed dog 38 in accordance with the swing of the first swing arm 32; a second swinging arm 23 that swings in the horizontal direction; one end is rotatably connected to the free end of the second swinging arm 23, and the other end is rotatably connected to the upper feed table 37; a second link 34 that is movably connected and for imparting horizontal movement to the upper feed dog 38 in accordance with the swinging of the second swinging arm 23;
a spring 44 acting on the upper feed table 37 to apply a downward pressing force to the upper feed dog 38; When the upper feed dog 38 is raised in accordance with the swing of the first swing arm 32, the rotation of the upper feed table 37 due to the action of the spring 44 is restricted, and the upper feed dog 3. An upper feed device for a sewing machine, characterized in that a stopper member 46 is provided to cause the work cloth to rise from the support surface 39 of the work cloth. 2. The upper feed device for a sewing machine according to claim 1, which is attached to the second link 34 of the spring 44.