JP2000279671A - Presser foot of sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity by permitting a worker to concentrate his consciousness on the setting of a cloth beneath a pressure foot by maintaining the presser foot in a raised position and a feed dog in a lowered position below the top face of a swash plate when a control means is engaged in the second position by operating the control means. SOLUTION: With the spindle 31 of a sewing machine stopped in a position where a needle gets into the top dead center, a main feed dog 34a projects out from the top face of a throat plate 29, and a presser bar 21 supporting the presser foot on the lower end is raised against a spring 26 through a cloth. When the spindle 31 rotates from this state, main and subsidiary feed bars 34 and 35 are moved up and down by a vertical feed cam 32 and moved also horizontally with a horizontal feed mechanism for four movements of cloth feed. Subsequently, to take out the cloth, the spindle 31 is stopped in a position where the needle gets into the top dead center. Subsequently the tip of a presser foot lifting lever 36 is pulled up and rotated around a shaft 37, the presser foot is lifted through a jamb 24 and feed dogs 34a and 35a are lowered through a connecting arm 39 or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a presser foot device for a sewing machine, and more particularly to a presser foot device for a sewing machine in which when a presser foot is raised, a cloth feed dog is lowered from the upper surface of a needle plate.

[0002]

2. Description of the Related Art As a cloth presser of this type, Japanese Utility Model No.
A technique disclosed in Japanese Patent No. 35729 is disclosed. Hereinafter, this conventional technique will be described with reference to FIGS. Reference numeral 1 denotes an upper shaft to which the eccentric cam 2 is fixed. 3
Is an upper and lower rod, the upper end of which is loosely fitted to the eccentric cam 3, and the lower end of which is connected to a square piece 5 which slides in a groove 4 a of the adjusting body 4 by a pin 6. Reference numeral 7 denotes a vertical feed link, the right end of which is connected to the pin 6, and the left end of which is connected to the lower end of the vertical feed arm 8. The upper end of the vertical feed arm 8 is fixed to a vertical feed shaft 9, and the base of the vertical feed bifurcation 10 is fixed to the vertical feed shaft 9.

A fork of a vertical feed fork 10 has a square piece 11
The square piece 11 is connected to a cloth feed table 13 supporting a cloth feed tooth 12. Reference numeral 15 denotes an engagement portion provided on the adjustment body 4. Reference numeral 16 denotes a shaft fixed to a frame (not shown). The shaft 16 has a cam 17 provided with a contact portion 17a engageable with the engaging portion 15 and a projecting portion 17b.
Are provided rotatably. Reference numeral 18 denotes a presser bar connected to a cloth presser mechanism (not shown).
A piece 19 which can be engaged with the projection 17b of the cam 17
And a contact portion 20 at the lower end for contacting a knee raising device (not shown).

[0004] The prior art has the above configuration. Next, the operation of the prior art will be described. FIG. 15 shows that the presser foot lifting rod 18 is lowered and the cloth presser (not shown) is at the lowered position. When the sewing machine is driven and the upper shaft 1 is rotated from this state, the upper and lower rods 3 are moved up and down by the eccentric cam 2. You. This vertical rod 3
, The square piece 5 slides up and down along with the pin 6 along the inclined groove 4 a of the adjusting body 4. When the pin 6 slides along the inclined groove 4a of the adjusting body 4, the vertical feed link 7 reciprocates left and right, whereby the vertical feed shaft 9 swings and the cloth feed tooth 12 moves vertically. Then, in cooperation with a horizontal feed mechanism (not shown), the cloth feed tooth 12 is moved four times for cloth feed to feed the cloth.

[0005] In this mechanism, the following is a method for taking in and out the cloth below the presser foot. First, in order to put the cloth in and out, the upper shaft 1 of the sewing machine is stopped at the top dead center of the needle bar where the needle is at the highest position so that the needle does not exist below the cloth presser. This state is the state shown in FIG. 15, and the cloth feed teeth 12 at this position are at the highest position from the upper surface of the needle plate because the cloth is being fed.

For this reason, in the conventional technique shown in FIG. 15, the knee raising device is maintained in the pressed state from the state shown in FIG. 15, and the contact portion 20 of the lifting bar 18 is moved upward as shown in FIG. Push up. As the presser bar 18 is raised, the cloth presser (not shown) rises from the upper surface of the needle plate, and the piece 19 pushes up the projecting portion 17 b of the cam 17 to move the cam 17 to the shaft 1.
6 is rotated counterclockwise. Due to this rotation, the contact portion 17a of the cam 17 pushes the engaging portion 15 of the adjusting body 4 downward, and rotates the adjusting body 4 clockwise, thereby rotating the vertical feed shaft 9 to feed the cloth. The teeth 12 are lowered below the upper surface of the needle plate. Thus, there is no obstacle between the lower surface of the presser foot and the upper surface of the needle plate to take out and put in the cloth, so that it is easy to put in and take out a thick cloth.

[0007]

However, this conventional technique has the following problems. That is, in this conventional technique, in order to set the presser foot to the raised position and lower the feed dog below the upper surface of the needle plate, the knee raising device is used while the cloth is taken in and out below the presser foot. Since it is necessary to maintain the pressed state, the worker's consciousness cannot concentrate on the setting of the cloth, and there is a problem that the workability is poor.

[0008] In addition to a knee raising device, a general sewing machine has a presser lifting lever that raises the presser foot by manual operation at the rear of the frame, so that a normal thin cloth can be put in and out below the presser foot. In many cases, the presser foot is raised using the presser foot lifting lever. For this reason, the worker must select whether to use the presser lifting lever or the knee raising device according to the thickness of the cloth, and the worker has to recognize extra, There is a problem of poor workability. Furthermore, raise the work clamp with the presser lifting lever,
When trying to set the cloth below the presser foot, if the cloth cannot be set thickly, the cloth feed dog must be lowered again by the knee raising device, and there is a problem that the working efficiency is reduced.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is a cloth presser which supports a presser foot, and is capable of moving up and down by always receiving a downward elastic force. A cloth feed means for supporting the cloth feeder and performing four movements of cloth feed in conjunction with the main shaft of the sewing machine; a cloth feed tooth lowering means for lowering the cloth feed tooth of the feed means below the upper surface of the needle plate; Operating means which can be locked at the first position and the second position, and by operating the operating means, the operating means is set to the first position, thereby lowering the presser foot of the cloth presser means, and By raising the cloth feed teeth from the upper surface of the needle plate by the lowering means and setting the operating means to the second position, the cloth presser of the cloth presser means is raised, and the cloth feed teeth are lowered from the upper surface of the needle plate by the cloth feed tooth lowering means. To be lowered.

According to the first aspect of the present invention, by operating the operating means, the operating means is locked at the first position, the cloth presser is at the raised position, and the cloth feed dog is located below the upper surface of the needle plate. Since it can be maintained at the lowering position, the worker's consciousness can concentrate on setting the cloth below the work clamp,
This has the effect of improving sewing work efficiency. In addition, the single presser can maintain the presser foot at the up position and the cloth feed dog at the lower position below the upper surface of the needle plate. Since there is no need to perform the sewing operation, mental fatigue of the worker is reduced, and the sewing work efficiency is improved.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. First, a first embodiment will be described with reference to FIGS.
FIG. 1 is a perspective view of a cloth presser, a cloth feeder, and an operation unit. FIG. 2 is a perspective view of a vertical feed cam, and FIG. 3 is a side view of a cloth pressing mechanism as cloth pressing means.

Reference numeral 21 shown in FIG.
The presser foot 23 is fixed to the lower end as shown in FIG. 3, and the holding body 24 is fixed to the middle part. 25 is an adjusting screw screwed into the frame 22, and the upper end of the holding rod 21 is loosely fitted. 26 is a spring,
The presser bar 21 is provided in a compressed state on the outer periphery of the presser bar 21 between the lower end surface of the adjusting screw 25 and the upper end surface of the holding member 24, and the presser bar 21 is pressed downward by its elastic force. Reference numeral 27 denotes a cloth presser, whose intermediate portion is rotatably supported by the lower end of the presser foot 23. Reference numeral 28 denotes a presser spring, the base of which is supported by the presser foot 23, and the front end of which presses the front end of the cloth presser 27 from above. 29 is a needle plate. Reference numeral 30 denotes a stopper, the upper end of which is screwed into the frame 22, and the lower end of which is located above the presser foot 27. The presser bar 21, the presser foot 23, the adjusting screw 25, the presser foot 27, and the like constitute a presser means.

Reference numeral 31 denotes a main shaft which is rotated by a driving means (not shown). A vertical feed cam 32 eccentric to the axis of the main shaft 31 is fixed to the main shaft 31. Reference numeral 33 denotes a vertical feed angle piece loosely fitted to the vertical feed cam 32. As shown in FIG. 2, the upper part 33a and the lower part 33b, which are different in height and whose upper and lower surfaces are flat, are provided between them. Slope 33
c and a connecting arm 33e having an elongated hole 33d formed in the end face.

Reference numeral 34 denotes a main cloth feed dog 34a and a bifurcated portion 34.
b is a main feeder provided with an auxiliary feed dog 35a.
And a fork part 35b provided with a fork part 35b.
b and 35b are normally located on the upper portion 33a of the upper feed cam 33 as shown in FIG.
5c is pressed against the high portion 33a. The main shaft 31, the vertical feed cam 32, the high portion 33a of the vertical feed square piece 33, the main feed base 34, the sub feed base 35, and the like constitute cloth feeding means. Also, the lower portion 33b of the vertical feed angle piece 33
Constitutes the cloth feed dog lowering means.

Next, the configuration of the operation means will be described.
Reference numeral 36 denotes a presser lifting lever.
3 is rotatably supported on a frame (not shown) by a shaft 37 below the holding member 24 as shown in FIG. 3, and a cam portion 36 a close to the shaft center of the shaft 37 and the shaft center of the shaft 37. A remote cam portion 36b is formed.

Reference numeral 38 denotes a horizontal shaft supported by a frame, and a connecting arm 39 is rotatably supported on the shaft 38. The connecting arm 39 has an arm 39a projecting upward.
And an arm 39b projecting obliquely downward.
Reference numeral 40 denotes a link, the upper end of which is connected to the lifting lever 36, and the lower end of which is connected to the arm 39 b of the connecting arm 39. 4
Reference numeral 1 denotes an L-shaped connecting plate, which has a vertical axis 4 with respect to the frame.
2 rotatably supported. One end of the L-shaped connecting plate 41 is connected to a connecting arm 39 by a ball joint 43.
The other end of the L-shape is connected to the upper feed cam 3
The upper feed cam 33 is connected to a connection arm 33e by a vertical shaft 44 that fits loosely into the third long hole 33d.

The first embodiment has the above configuration, and the operation will be described next. FIGS. 1 and 3 to 6 show a state in which the main shaft 31 of the sewing machine is stopped at a position where a needle (not shown) becomes a top dead center. In this state, the presser lift lever 3
6 is at the first position shown in FIG. 3, and the main feed dog 34 a rises most from the upper surface of the needle plate 29, and
7 is raised together with the holding bar 21 against the elastic force of the spring 26, and the lower surface of the holding body 24 is located above the cam portion 36 a of the holding lever 36. In this state, the vertical feed cam 33 is located at the position shown in FIGS. 4, 5, and 6, and the forked portions 34b and 35b of the main feed base 34 and the sub feed base 35 are connected to the vertical feed cam. 33 high part 33a
Are pressed against each other by springs 34c and 35c.

When the main shaft 31 rotates from this state, the main feed bar 34 and the sub feed bar 35 move up and down by the vertical feed cam 32, and also move in the horizontal direction by a horizontal feed mechanism (not shown). As a result, the main feed dog 34a and the sub feed dog 35a protrude and retract from the upper surface of the needle plate 29,
Four movements of cloth feeding are performed in cooperation with the cloth presser 27. And
To take out the cloth W, as shown in FIG. 3, the main shaft 31 is stopped at the position where the needle is at the top dead center, and each part is in the state shown in FIGS.

From this state, the lifting lever 3 shown in FIG.
6 is lifted, and the presser lifting lever 36 is turned about 90 degrees counterclockwise about the shaft 37. This rotation causes the cam portion 36b of the presser lifting lever 36 to hold the holding portion 24b.
7 against the elastic force of the spring 26 as shown in FIG.
At the same time, the presser foot 27 is raised, and the presser foot lifting lever 36 is locked at the second position shown in FIG.

When the presser bar 21 starts to rise, the presser foot 27
First, the tip of the cloth presser 27 is pressed downward by the presser spring 28 and tilts. When the presser foot 27 further rises, the presser foot 2
7 comes into contact with the stopper 30, and
Is raised, the presser foot 27 becomes horizontal as shown in FIG. 7, and the presser foot lifting lever 36 is locked at the second position. Further, the link 40 shown in FIG. 1 is pulled up by the rotation of the presser lifting lever 36, whereby the connecting arm 3
9 rotates clockwise around the horizontal shaft 38.

Further, when the connecting arm 39 is rotated, the connecting plate 41 is rotated clockwise about the vertical shaft 42 via the ball joint 43 as shown in FIG. Further, the rotation of the connecting plate 41 is transmitted from the shaft 44 to the connecting arm 33e of the vertical feed cam 33, and moves the vertical feed cam 33 rightward along the outer periphery of the eccentric cam 32 as shown in FIG. This vertical feed cam 3
By the movement of 2, the main feed bar 34 and the sub feed bar 35, which have been pressed against the high portion 33a of the vertical feed cam 32 by the springs 34c and 35c, move onto the low portion 33b, and the main feed dog 34
a and the auxiliary feed dog 35a are connected to the needle plate 2 as shown in FIGS.
9 descends below the upper surface.

In the state shown in FIGS. 7 and 10, the cloth W is taken in and out. Closing and unloading of cloth W is completed,
In order to lower the main feed dog 34a and the sub feed dog 35a, the holding lever 36 locked at the second position in FIG. Lock in one position. By this operation, each part rotates or moves in the direction opposite to the above, and the state shown in FIGS. 3 to 6 is reached, the work clamp 27 is lowered, and the main feed dog 34a and the sub feed dog 35a are raised.

Next, a second embodiment will be described with reference to FIGS. The second embodiment has a configuration in which a part of the above-described first embodiment is modified. Therefore, only the configuration of the modified operation means will be described. The upper end of the link 40 is rotatably connected to the body 24 by a pin 45. Reference numeral 46 denotes an electromagnet fixed to the frame, which is turned ON and OFF by an operator's switch operation. The armature 47 is rotatably connected to the shaft 44 via a link 48.

FIG. 11 shows a state in which the electromagnet 46 is locked at the first position. From this state, when the electromagnet 46 is turned on by a switch operation and the armature 47 moves rightward and is locked at the second position, the link 48
, The shaft 44 is pulled to the right. Thereby, first, the connecting plate 41 rotates counterclockwise about the vertical shaft 42,
The connecting arm 39 is rotated clockwise about the horizontal shaft 38 via the ball joint 43. Due to the rotation of the connecting arm 39, the holding bar 21 is raised against the spring 26 via the link 40, and the cloth presser 27 is raised. When the shaft 44 is pulled to the right, the vertical feed cam 33 is moved via the connecting arm 33e of the vertical feed cam 33 as shown in FIGS. 8 and 9 to move the main feed tooth 34a and the sub feed tooth 35a. Is lowered as shown in FIG.

When the loading and unloading of the cloth is completed and the electromagnet 46 is turned off by a switch operation, the armature 47 moves leftward and the electromagnet 46 is locked at the first position.
When the armature 47 moves back, the respective parts rotate or move in the opposite directions to the above, the work clamp 27 descends as shown in FIG. 12, and the vertical feed cam 33 moves to the position shown in FIGS. Then, the main feed dog 34a and the sub feed dog 35a rise as shown in FIG.

Next, a third embodiment will be described with reference to FIGS. This embodiment is a configuration of the operation means in which a part of the conventional technology described and described with reference to FIGS. 15 and 16 is changed, and the same components as those of the conventional technology have the same part numbers and names as those of the conventional technology. , Detailed description of the configuration will be omitted, and only the configuration of the operation means having a different configuration will be described.

Reference numeral 49 denotes an electromagnet fixed to the frame, which is turned on and off by an operator's switch operation. The armature 50 is provided with a compression spring 51. Also, at the tip of this armature 50,
A cam 52 having a lower portion 52a, a higher portion 52b and a slope 52c connecting the lower portion 52a and the higher portion 52b is connected, and the cam 52 is slidable on a horizontal surface 53.

FIG. 13 shows a state in which the electromagnet 49 is locked at the first position. In this state, the contact portion 2
In this state, the presser foot is at the lowered position, and the cloth feed dog 12 is above the needle plate upper surface. From this state, when the electromagnet 49 is turned on by a switch operation of the operator, the armature 50 is pulled to the left against the elastic force of the compression spring 51.
The cam 52 moves to the position shown in FIG. 14, and the electromagnet 49 is locked at the second position. As a result, the lower end of the contact portion 20 is pushed up from the lower portion 52a of the cam 52 by the slope 52c and moves to the higher portion 52b. With this, the lifting bar 18
Is pushed upward, and the work clamp is raised. As described above, when the cam 52 moves to the left and the lifting bar 18 is pushed up, the piece 19 pushes up the projecting portion 17b of the cam 17, and the cam 19 rotates clockwise about the shaft 16. I do. The rotation of the cam 17 causes the contact portion 17 of the cam 17 to rotate.
a pushes down the engagement portion 15 of the adjusting body 4 downward,
Is rotated clockwise. By the rotation of the adjusting body 4, the vertical feed shaft 9 is rotated via the vertical feed link 7 and the vertical feed arm 8, and the feed dog 12 is lowered below the upper surface of the needle plate.

When the electromagnet 49 is turned off from the state shown in FIG. 14, the armature 5
0 returns to the position shown in FIG. 13, and the electromagnet 49 is locked at the first position shown in FIG. As a result, the respective parts move or rotate in the opposite directions to the above, and the presser foot is lowered, and the feed dog 12 is at the raised position. In addition,
The present invention is not limited to the configuration shown in the above embodiment, and can be appropriately modified without departing from the invention.

[0030]

As described above, according to the sewing machine cloth presser of the present invention, the operating means is locked at the second position by operating the operating means, and the cloth presser is moved to the raised position and the cloth feeder is moved. Since the teeth can be respectively maintained at the lower positions below the upper surface of the needle plate, the worker's consciousness can be concentrated on setting the cloth below the presser foot, and there is an effect that the workability is excellent and the sewing work efficiency is improved.

Further, since the presser foot can be maintained at the raised position and the feed dog can be maintained at the lowered position below the upper surface of the needle plate by a single operating means, the operating member for lifting the presser foot can be selected according to the thickness of the cloth. Since there is no need to perform such operations, there is an effect that the mental fatigue of the operator is reduced and the sewing work efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a cloth presser, a cloth feeder, and an operation unit according to the first embodiment.

FIG. 2 is a perspective view of a vertical feed cam.

FIG. 3 is a side view of a cloth presser mechanism serving as a cloth presser in which an operation unit is locked at a first position.

FIG. 4 is a plan view of a vertical feed cam portion in a state where an operation means is set to a first position.

FIG. 5 is a longitudinal sectional view of FIG.

FIG. 6 is a side view of the cloth feed dog in a state where the operation means is in a first position.

FIG. 7 is a side view of a cloth presser mechanism serving as a cloth presser in which an operation unit is locked at a second position.

FIG. 8 is a plan view of the vertical feed cam portion in a state where the operation means is at a second position.

FIG. 9 is a longitudinal sectional view of FIG.

FIG. 10 is a side view of the cloth feed dog in a state where the operation means is at a second position.

FIG. 11 is a perspective view of a cloth presser, a cloth feeder, and an operation unit according to the second embodiment.

FIG. 12 is a side view of a cloth presser mechanism serving as a cloth presser in which the operation unit of the second embodiment is locked at a first position.

FIG. 13 is a schematic perspective view of a cloth presser, a cloth feeder, and an operating means according to a third embodiment in which the operating means is locked at a first position.

FIG. 14 is a schematic perspective view of the cloth holding means, the cloth feeding means, and the operating means of the third embodiment in which the operating means is locked at the second position.

FIG. 15 is a schematic perspective view of a related art in a state in which a work clamp is lowered.

FIG. 16 is a schematic perspective view of a related art in a state in which a pressure foot is raised.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Presser bar 27 Cloth presser 29 Needle plate 33 Vertical feed cam 34 Main feed bar 34a Main feed dog 35 Sub feed bar 35a Sub feed dog 36 Pressing up lever (operating means) 46 Electromagnet (operating means) 49 Electromagnet (operating means) 52 Cam -1-

Claims (1)

[Claims] 1. A cloth presser means for supporting a cloth presser and capable of always moving up and down by receiving a downward elastic force, and a cloth feed means for supporting a cloth feed tooth and performing four movements of cloth feed in conjunction with a main shaft of a sewing machine. Cloth feed teeth lowering means for lowering the cloth feed teeth of the feed means below the upper surface of the needle plate; and operating means capable of being locked at a first position and a second position by an operation of an operator. By operating the operating means, the operating means is brought to the first position, the cloth presser of the cloth pressing means is raised, and the cloth feed teeth are lowered by the cloth feed tooth lowering means below the upper surface of the needle plate. A cloth presser device for a sewing machine, wherein the cloth presser of the cloth presser means is lowered by setting the second position, and the cloth feed teeth are raised from the upper surface of the needle plate by the cloth feed tooth lowering means.