JP2734739B2 - Sewing machine top feeder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an upper feed device for a sewing machine, and more particularly to an upper feed device for a sewing machine capable of adjusting a rising amount of an upper feed dog.

[Prior Art] Conventionally, for example, Japanese Utility Model Publication No. Sho 60-12521,
No. 12522 and Japanese Utility Model Publication No. 62-31100 disclose an upper feed device for a sewing machine having an adjusting mechanism for stopping the sewing machine and adjusting the vertical reciprocating amount of the upper feed dog in accordance with the thickness of the work cloth. Have been described.

The adjusting mechanism includes a connecting link having one end rotatably connected to a transmission lever that swings by rotation of the main shaft of the sewing machine via a support shaft, and a tip rotatably positioned at the other end of the connecting link. A setting lever pivotally supported by the sewing machine frame, the base end being pivotally supported by the sewing machine frame, and an up-down feed arm having a vertical reciprocating movement amount that changes according to the amount of swing of the setting lever. It is composed of

An arc-shaped setting groove is formed through the setting lever. At the other end of the connection link, a stepped pin fitted into the setting groove is provided so as to be movable along the setting groove. The stepped pin of the connecting link and the setting lever are fixed between the nut and the free end side end face of the setting lever by tightening the nut on the outer periphery of the stepped pin inserted through the setting groove of the setting lever. This is done by pinching the lever.

To adjust the amount of rise of the upper feed dog, after stopping the sewing machine, loosen the nut to release the fixation of the nut to the setting lever, and adjust the position of the stepped pin of the connecting link to the thickness of the work cloth along the setting groove. The amount of movement of the upper and lower feed arms is changed by moving the arm by an amount corresponding to the distance, and retightening the nut at that position to fix the connecting lever to the setting lever. As a result, the amount of reciprocation of the upper feed bar in the vertical direction is changed, so that the amount of elevation of the upper feed dog is adjusted.

[Problems to be Solved by the Invention] However, in the conventional upper feed device of the sewing machine, when the work cloth has a very small thickness, the amount of elevation of the upper feed dog is increased according to the thickness of the work cloth. In order to adjust the so-called upper feed dog to zero feed in order to approach zero as much as possible, it is necessary to extend the setting groove of the setting lever in a direction away from the support shaft as compared with the current setting lever.

If the setting groove is to be extended in a direction away from the support shaft as compared with the current state, the setting lever interferes with other internal parts in the sewing machine, so that the outer shape of the sewing machine must be enlarged.

As a result, in the conventional upper feed device of the sewing machine, there is a problem that the vertical reciprocating motion amount of the upper feed dog cannot be adjusted in a wide range according to the thickness of the work cloth without increasing the outer shape of the sewing machine. there were.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an upper feed device for a sewing machine which can adjust a vertical movement range of an upper feed dog in a wide range without increasing the outer shape.

[Means for Solving the Problems] An upper feed device for a sewing machine according to the present invention includes an upper feed dog for giving a feed motion to a work cloth by four motion feeds, and connecting the upper feed dog to the upper feed tooth in a vertical direction. An upper feed device for a sewing machine, comprising: a vertical drive unit that provides reciprocating motion of the sewing machine; and a horizontal drive unit that connects the upper feed dog to reciprocate the upper feed dog in a horizontal direction. A rotating shaft for performing a reciprocating motion at a predetermined rotation angle, a lever provided on the rotating shaft, an end portion swinging by the rotating motion of the rotating shaft, and one end connected to the lever, A link having an end operatively connected to the upper feed dog, wherein the lever passes over an axis of the rotation shaft and is provided with a groove, a hole, a protrusion, or the like provided toward the end. A first fitting portion, wherein the link is fitted to the first fitting portion; A second movable member which is provided to be movable along the first fitting portion;
A technical means having a fitting portion was employed.

[Operation] The reciprocating motion of the rotation shaft at a predetermined rotation angle causes the end of the lever to swing by a predetermined swing amount, and the closer to the axis of the rotation shaft from the end of the lever, the closer to the end of the lever. The rocking momentum naturally decreases.

Therefore, by moving the second fitting portion of the link along the first fitting portion of the lever, the momentum given by the lever to the link changes depending on the distance between the axis of the rotating shaft and the second fitting portion. I do. Therefore, the amount of reciprocation of the upper feed dog in the vertical direction also changes according to the distance between the axis of the rotation shaft and the second fitting portion.

For example, since the first fitting portion of the lever is provided so as to pass on the axis of the rotating shaft, the second fitting portion of the link can be located on the axis of the rotating shaft. At this time, the swinging momentum of the first fitting portion of the lever fitted to the second fitting portion of the link becomes zero.

As a result, by moving the second fitting portion of the link along the first fitting portion of the lever and positioning it on the axis of the rotation shaft, the momentum of the driving means connected to the other end of the link Is also 0, the reciprocating motion amount of the upper feed dog in the vertical direction becomes 0, and the upper feed dog is adjusted to 0 feed.

[Effect of the Invention] By positioning the second fitting portion of the link on the axis of the rotation shaft, zero feed adjustment of the upper feed dog can be performed, so that it is necessary to extend the lever as in the conventional case. There is no.

As a result, the vertical movement range of the upper feed dog can be adjusted over a wide range without interfering with other internal parts of the sewing machine and without increasing the outer contour of the sewing machine.

Next, an upper feed device of the sewing machine of the present invention will be described based on an embodiment shown in the drawings.

(Structure of Embodiment) FIGS. 1 to 5 show an embodiment of the present invention, and FIG.
FIGS. 3 and 3 are diagrams showing a link mechanism of the upper feed device of the sewing machine, and FIGS. 4 and 5 are diagrams showing an upper feed tooth raising mechanism of the upper feed device of the sewing machine.

B) Schematic description of the upper feed device 1 of the sewing machine.

The upper feed device 1 of the sewing machine includes a horizontal drive mechanism 3 for causing the upper feed dog 2 to reciprocate horizontally. This horizontal drive mechanism 3 is a horizontal drive means of the present invention,
Has a horizontal feed momentum adjusting mechanism 4 for adjusting the reciprocating momentum in the horizontal direction. Further, the upper feed device 1 of the sewing machine is provided with a vertical drive mechanism 5 for giving the upper feed dog 2 a reciprocating motion in the vertical direction. The vertical drive mechanism 5 is a vertical drive means of the present invention, and has a vertical feed momentum adjustment mechanism 6 for adjusting the vertical reciprocating motion of the upper feed dog 2. Further, the upper feed device 1 of the sewing machine includes an upper feed tooth raising mechanism 8 that raises the upper feed tooth 2 when raising the work clamp 7.

B) Description of the horizontal drive mechanism 3.

An eccentric wheel 10 is fixed to a drive shaft 9 that rotates in one direction, and a swinging motion is transmitted to a horizontal feed shaft 13 via a feed rod 11 and a horizontal feed arm 12. At the end of the horizontal feed shaft 13, a horizontal feed adjusting arm 16 in which a square piece 15 is fitted into a groove 14 having a U-shaped cross section is fixed. One end of a horizontal feed link 17 is fitted into the square piece 15. The other end of the horizontal feed link 17 is connected to a horizontal crankshaft arm 19 fixed to a horizontal crankshaft 18 by a pin 20, and transmits the swinging motion of the horizontal feed adjustment arm 16 to the horizontal crankshaft 18. I have. An end of the horizontal crankshaft 18 includes a horizontal driving body 21 extending downward, and a tip of the horizontal driving body 21 is rotatably connected to one end of an upper feed base 22. As a result,
A reciprocating motion in the horizontal direction is transmitted to 22 in accordance with the reciprocating motion of the sewing needle 23 in the vertical direction.

C) Description of the horizontal feed momentum adjustment mechanism 4.

One end (horizontal piece 15) of the horizontal feed link 17 of the horizontal drive mechanism 3
One end of the horizontal feed adjusting link 24 is fitted into the (side). The other end of the horizontal feed adjustment link 24 is connected to one end of a first horizontal feed adjustment lever 25. The other end of the first horizontal feed adjustment lever 25 has a pin 26 rotatably supported.
, Is fixed to one end of the second horizontal feed adjustment lever 27. The other end of the second horizontal feed adjustment lever 27 protrudes from the outside of the frame 29 that houses the internal mechanisms,
It is fixed to a horizontal feed scale plate 30 fixed to 29 by a thumb screw 31.

As a result, by loosening the thumbscrew 31 and moving the other end of the second horizontal feed adjustment lever 27 on the horizontal feed scale plate 30, the square piece 15 moves along the groove 14, and the square piece 15 The length of the horizontal feed shaft 13 and the axis of the horizontal feed shaft 13 change, and the amount of reciprocating movement in the horizontal direction transmitted to the upper feed base 22 is adjusted. For example, when the second horizontal feed adjustment lever 27 is positioned at the zero point graduated on the horizontal feed scale plate 30, the square piece 15 is positioned on the axis of the horizontal feed shaft 13 of the groove 14. For this reason, even if the horizontal feed shaft 13 swings, the amount of movement transmitted from the horizontal feed adjusting arm 16 to the upper feed base 22 becomes zero, and the reciprocating movement amount of the upper feed dog 2 in the horizontal direction becomes zero. .

D) Description of the vertical drive mechanism 5.

A vertical feed adjusting lever in which a square piece 34 is fitted into a groove 33 having a U-shaped cross section at the end of a rotating shaft 32 that performs a swinging motion at a predetermined rotation angle in conjunction with the drive shaft 9. Fix 35.
The groove 33 is an example of the first fitting portion of the present invention,
34 is an example of the second fitting portion of the present invention. This groove 33
The vertical feed adjusting lever 35 is formed to pass through the axis of the rotating shaft 32 toward the left end in the drawing. Further, the groove 33 is formed so as to be located in an arc shape centered on 39 when the upper feed dog 2 is located at the lowered position.

The square piece 34 is provided movably along the groove 33.
One end of a vertical feed link 36 is fitted into the square piece 34. The other end of the vertical feed link 36 is a vertical crankshaft.
A pin 39 is connected to an upper and lower crankshaft arm 38 fixed to 37, and transmits a swinging motion of the vertical feed adjustment lever 35 about the axis of the rotating shaft 32 to the upper and lower crankshafts 37. . At the end of the upper and lower crankshafts 37, there is provided a vertical driving body 40 extending in the horizontal direction. On the free end side of the vertical driving body 40, a square piece 43 that transmits a reciprocating motion in the vertical direction is fitted into a connecting portion 42 on the free end side of the transmission lever 41. As a result, with the vertical reciprocating movement of the sewing needle 23, the connecting portion 42 of the transmission lever 41 reciprocates in the vertical direction.

The transmission lever 41 is rotatably supported by a support portion 45 on a free end side of an upper feed support arm 44 described later. The connecting portion 42 on the free end side of the transmission lever 41 is provided in a forked shape, and is connected to the square piece 43 inside the forked portion.
The transmission lever 41 has a hole 46 substantially at the center between the support portion 45 and the connecting portion 42, and a guide 47 is fitted into the hole 46. That is, the transmission lever 41 is provided with the guide 47 between the support portion 45 and the connection portion 42. The guide 47 includes a groove 48 having a U-shaped cross section. The central portion of the upper feed base 22 is fitted into the groove 48, and supports the upper feed base 22 so as to be movable in the horizontal direction. And this guide 47 is attached to the upper feed table 22 and the sewing needle 23.
The up-down reciprocating motion is transmitted with the up-down reciprocating motion.

The upper feed dog 2 is fixed to the tip of the upper feed base 22 with a screw 49. The upper feed dog 2 synthesizes the horizontal and vertical reciprocating motions transmitted by the horizontal drive mechanism 3 and the vertical drive mechanism 5 to perform an elliptical feed motion (so-called four motion feed) in the normal rotation direction. The work cloth placed on the work cloth placement surface of the needle plate 50 is transferred in cooperation with a lower feed dog (not shown).

On the other hand, the guide 47 is directly urged toward the work cloth by the urging means 51. The urging means 51 will be specifically described. The urging means 51 includes a presser rod 52 placed on the upper side of the guide 47, a presser adjusting screw 53 for contacting this urging force,
It is composed of a compression coil spring 54 disposed between the presser bar 52 and the presser adjusting screw 53. The urging force of the urging means 51 is used when the upper feed dog 2 is operated at a high speed.
Are set large so as to follow the movement of the vertical drive mechanism 5.

On the other hand, the upper feed support arm 44 is rotatably supported around an upper feed support shaft 56 via a metal 55. The upper feed support arm 44 includes a stopper 57 extending upward. When the stopper 57 hits the frame 29, the upper feed support arm 44
The position of the lower end of the support part 45 of 44 is regulated.

E) Description of the vertical feed momentum adjustment mechanism 6.

One end of the vertical feed link 36 of the vertical drive mechanism 5 (the square piece 34
One end of the vertical feed adjustment link 58 is fitted into the (side). The other end of the vertical feed adjusting link 58 is connected to one end of a first vertical feed adjusting lever 59. The other end of the first vertical feed adjusting lever 59 has a pin 60 rotatably supported.
, Is fixed to one end of the second vertical feed adjustment lever 61. The other end of the second vertical feed adjustment lever 61 is a frame
It is fixed by a thumb screw 62 to a vertical feed scale plate (not shown) that protrudes from the outside of the frame 29 and is fixed to the frame 29.

As a result, by loosening the thumb screw 62 and moving the other end of the second vertical feed adjusting lever 61 on the vertical feed scale plate, the square piece 34 moves along the groove 33, and As the length of the rotation shaft 32 and the axis changes, the amount of vertical reciprocating motion transmitted to the guide 47 is adjusted.

F) Description of the upper feed dog raising mechanism 8.

The upper feed dog raising mechanism 8 is a rotary motion applying means of the present invention which applies a rotational motion to the upper feed support arm 44 and moves the support portion 45 upward against the urging force of the urging means 51. An intermediate lever 63 is provided. The intermediate lever 63 is substantially L
The bent portion is rotatably supported around an upper feed support shaft 56 via a metal (not shown). And one free end of the presser lifting intermediate lever 63 is
It extends upward and faces an adjustment screw 64 screwed into a stopper 57 of the upper feed support arm 44 via a certain gap. A protruding portion of the collar 65 fixed to the upper feed support shaft 56 is provided on a free end side extending above the presser lifting intermediate lever 63.
Both faces each other with a certain gap. The other free end of the presser lifting intermediate lever 63 extends in the horizontal direction and is connected to a foot pedal (not shown) via a transmission mechanism (not shown). By adjusting the above two gaps, it is possible to adjust the rising amount and the rising timing of the upper feed dog 2 and the presser foot 7.

A holding arm 67 is fixed to an end of the upper feed support shaft 56. A cloth presser 7 that presses the work cloth toward the needle plate 50 from above the work cloth is fixed to the free end side of the presser arm 67 with a screw. The free end side of the holding arm 67 is urged downward by the urging means 68.

As a result, when the operator steps on the foot pedal, the presser-lifting intermediate lever 63 is rotated via the transmission mechanism, and the upper feed support arm 44 and the upper feed support shaft 56 are rotated. The presser foot 7 rises together.

(Operation of Embodiment) Next, the operation of the embodiment of the portion according to the present invention will be briefly described.

G) Operation when adjusting the amount of elevation of the upper feed dog 2 with a thick work cloth.

If the work cloth is thick, the sewing machine is stopped and the upper feed dog 2 is positioned at the lower position.

The groove 33 of the vertical feed adjusting lever 35 is formed so as to be located in an arc shape centering on the pin 39 when the upper feed dog 2 is located at the lowered position. As a result, even when the vertical feed link 36 is rotated about the pin 39, the position of the upper and lower crankshaft arms 38 does not change, so that the upper feed dog 2 is kept at the lowered position.

By loosening the thumb screw 62 protruding outside the frame 29 provided at the other end of the second vertical feed adjusting lever 61, the vertical feed scale plate fixed to the frame 29 and the second vertical feed adjusting lever Release the fixation with 61.

Thereafter, the second vertical feed adjustment lever 61 is moved in the direction of arrow A about the pin 60 according to the thickness of the work cloth along the vertical feed scale plate. Then, one end of the first vertical feed adjusting lever 59 moves in the direction of arrow B around the pin 60. Therefore, the vertical feed adjustment link 58 moves in the direction of arrow B with the square piece 34.

Then, the square piece 34 moves along the groove 33 of the vertical feed adjustment lever 35 in a direction away from the axis of the rotating shaft 32. For this reason, the vertical feed link 36 in which the square piece 34 is
And is set in the position shown in FIG. Then, the thumb screw 62 is tightened again to fix the vertical feed scale plate and the second vertical feed adjusting lever 61 so that the position of the square piece 34 does not shift.

Therefore, in the vertical feed adjusting lever 35, since the square piece 34 is located at a position where the swinging momentum is large, when the rotating shaft 32 swings, the vertical feed adjusting lever 35 moves the vertical feed link 36, the vertical crankshaft. The swing amount transmitted to the upper and lower crankshafts 37 via the arm 38 is larger than before the movement.

Therefore, the momentum transmitted from the upper and lower crankshafts 37 to the upper feed base 22 via the guides 47 of the transmission lever 41 becomes larger than before the movement.

As a result, the amount of reciprocation of the upper feed dog 2 in the vertical direction, that is, the rising amount of the upper feed dog 2 becomes larger than before the movement, and the upper feed dog 2 is raised when the work cloth is transferred by the upper feed dog 2. In this case, the work cloth is reliably separated from the work cloth, so that the work cloth is not adversely affected when the work cloth is fed in the opposite direction.

H) The operation when adjusting the rising amount of the upper feed dog 2 with a thin work cloth.

When the work cloth is thin, the sewing machine is stopped and the upper feed dog 2 is positioned at the lowering position as in the case of the thick work cloth.

Then, by loosening the thumb screw 62, the fixing between the vertical feed scale plate and the second vertical feed adjusting lever 61 is released,
The second vertical feed adjusting lever 61 is moved in the direction of arrow D about the pin 60 in accordance with the thickness of the work cloth along the vertical feed scale plate. Then, one end of the first vertical feed adjustment lever 59 moves in the direction of arrow E around the pin 60,
The vertical feed adjustment link 58 also moves in the direction of arrow E with the square piece 34.

Then, the square piece 34 moves in the direction approaching the axis of the rotation shaft 32 along the groove 33 of the vertical feed adjusting lever 35, and the vertical feed link 36 moves in the direction of arrow F around the pin 39. Then, the thumb screw 62 is tightened again.

Therefore, in the vertical feed adjusting lever 35, the square piece 34 is located at a position where the swinging momentum is small, so that when the rotating shaft 32 swings, it is transmitted from the vertical feed adjusting lever 35 to the upper feed base 22. The momentum is smaller than before the movement.

As a result, the reciprocating amount of the upper feed dog 2 in the vertical direction, that is, the rising amount of the upper feed dog 2 becomes smaller than before the movement.

In this embodiment, since the groove 33 is formed so as to pass on the axis of the rotating shaft 32, when the thickness of the work cloth is very thin, the square piece 34 is formed on the rotating shaft 32. Can be approached as much as possible. For example, when the second vertical feed adjusting lever 61 is positioned at the zero point marked on the vertical feed scale plate, the square piece 34 is positioned on the axis of the rotating shaft 32 of the groove 33.

Since the axis of the rotating shaft 32 is also the axis of the vertical feed adjusting lever 35, the swing amount of this portion is zero regardless of the swing amount of the rotating shaft 32.

As a result, the amount of movement transmitted to the upper feed base 22 by the vertical feed adjusting lever 35 even when the rotary shaft 32 swings becomes zero, so that the vertical reciprocation of the upper feed dog 2, that is, the upper feed Tooth 2 feeds 0.

(Effect of Embodiment) As shown in the above embodiment, the thumbscrew 62 is loosened,
By moving the other end of the second vertical feed adjusting lever 61 on the vertical feed scale plate, the square piece 34 is brought closer to the axis of the rotating shaft 32 which is the center of the swinging motion of the vertical feed adjusting lever 35. ,
By tightening the thumbscrew 62 again, the amount of elevation of the upper feed dog 2 can be minimized. That is, since the upper feed dog 2 can be adjusted to zero feed, even when the work cloth is very thin, it can be adjusted to the optimum amount of the upper feed dog 2 raised.

If the work cloth is thick, loosen the thumbscrew 62,
By moving the other end of the second vertical feed adjusting lever 61 on the vertical feed scale plate, the square piece 34 is moved away from the axis of the rotating shaft 32, and the thumb screw 62 is tightened again, so that the work cloth is formed. It can be adjusted to the optimum amount of elevation of the upper feed dog 2 according to the thickness of the upper feed dog.

As a result, the horizontal feed momentum adjusting mechanism 4 and the vertical feed momentum adjusting mechanism 6 cooperate to form the square pieces 15, 34 on the axes of the horizontal feed adjusting arm 16 and the vertical feed adjusting lever 35.
The zero feed adjustment of the upper feed dog 2 can be performed by positioning. Therefore, the amount of elevation of the upper feed dog 2 can be adjusted in a wide range without interfering with the other internal parts of the sewing machine or increasing the outer contour of the sewing machine.

(Modifications) The present invention can be variously deviated without departing from the gist of the present invention.

The first fitting portion may be of various types such as a hole, a protrusion, a convex portion or a rail in addition to the groove 33, and the second fitting portion may be fitted to the first fitting portion in addition to the square piece 34. Anything can be used as long as it can move along the first fitting portion.

In this embodiment, the vertical drive means is provided with a vertical feed adjustment lever.
35, the vertical feed link 36 and the link mechanism, but at least the vertical feed adjustment lever 35, the vertical feed link
Various structures can be adopted as long as the vertical drive means is constituted by 36.

The shapes of the levers and the links are not limited to the vertical feed adjusting lever 35 and the vertical feed link 36 of this embodiment, and various descriptions can be changed.

[Brief description of the drawings]

1 to 5 show an embodiment of the present invention. FIG. 1 is a side view of a main part of an upper feed device of a sewing machine, and FIGS. 2 and 3 show a link mechanism of the upper feed device of the sewing machine. FIG. 4 is a side view of the upper feed dog raising mechanism, and FIG. 5 is a rear view of the upper feed dog raising mechanism. In the drawing, 1... Upper feed device of sewing machine 2... Upper feed dog 3... Horizontal drive mechanism (horizontal drive means) 4... Horizontal feed momentum adjustment mechanism 5... Vertical drive mechanism (vertical drive means) 6. Vertical feed momentum adjustment mechanism 33 Groove (first fitting part) 34 Square piece (second fitting part) 35 Vertical feed adjustment lever 36 Vertical feed link

Claims (1)

(57) [Claims] 1. An upper feed dog that feeds a work cloth by four motion feeds; an upper and lower drive unit that connects the upper feed dog to reciprocate the upper feed tooth in a vertical direction; A horizontal drive means for connecting the upper feed dog to reciprocate horizontally in the upper feed dog.The upper feed device of the sewing machine, wherein the upper and lower drive means comprises a rotating shaft for reciprocating at a predetermined rotation angle, A lever provided on the rotating shaft, the end of which swings by the rotating movement of the rotating shaft; and a link having one end connected to the lever and the other end operatively connected to the upper feed dog. And the lever has a first fitting portion such as a groove, a hole, or a convex portion provided on the axis of the rotation shaft toward the end portion, and the link is Being fitted to the first fitting portion and movable along the first fitting portion An upper feed device for a sewing machine, comprising a second fitting portion provided.