JP2001347087A - Feed dog retracting device for sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute the structure of a feed dog retracting device with simple and inexpensive parts, to manufacture the device easily, and to improve the durability of the device. SOLUTION: This feed dog retracting device comprises a feed dog performing the elliptic movement projecting from or retracting from the upper surface 4a of a needle plate 4 according to the upward or downward movement by a horizontal feed drive part 200 generating the horizontal feeding movement from a drive shaft and a vertical drive part 2000 generating the vertical movement, and a presser foot 6 separating from or abutting to the feed dog via a presser bar 41 by pushing up/down operation of a push-up lever 45. The feed dog retracting device also has a feed dog operating clutch 10 between the vertical drive part 2000 and the feed dog 5 for shutting the vertical movement transmitted to the feed dog 5 by interlocking with the push-up operation of the push-up lever 45, retracting the feed dog 5 to the position retreating from the upper surface 4a of the needle plate 4, and transmitting the vertical movement to the feed dog 5 by interlocking with the push-down operation of the push-up lever 45.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed dog retraction device for a sewing machine, and more particularly to a method for preparing a sewing product cloth at an initial position of a sewing operation by raising a presser foot before starting a sewing operation.
The present invention relates to a feed dog retraction device for a sewing machine that can retreat a feed dog from an upper surface of a needle plate when a sewing product cloth is displaced and placed at another sewing operation position.

[0002]

2. Description of the Related Art Conventionally, in a feed dog control mechanism of a sewing machine, an elliptical motion is given to a feed dog that feeds a cloth between a presser foot and a sewing machine during a sewing process. More specifically, the feed dog is raised from an inoperative position located below the needle plate to an operating position located above the needle plate, is advanced forward in the feed direction of the sewn cloth, and is again positioned below the needle plate. Down to the inoperative position
The steps of ascending again to the working position located above the throat plate are repeated, giving an elliptical movement.

In this case, the movement of the needle and the movement of the feed dog are both performed when the needle is near the position of the top dead center, so that the feed dog moves when the needle is raised. It is operated synchronously so as to protrude from the upper surface of the needle plate.

[0004] Therefore, before starting the sewing operation, when the presser foot is raised to prepare the sewing product cloth at the initial position of the sewing operation, or when the sewing product cloth is displaced and arranged at another sewing operation position, the feeding operation is performed. With the teeth protruding from the upper surface of the needle plate,
These spaces are so narrow that preparations and transitions due to the friction are troublesome, and the feed dog is rather an obstacle.

[0005] In such a background, before starting the sewing operation, the presser foot is raised to prepare the sewing product cloth at the initial position of the sewing operation, or the sewing product cloth is displaced and placed at another sewing operation position. In each case, a manual device for lowering the feed dog from the upper surface of the needle plate has been proposed.

Further, when the presser foot is raised to prepare the sewn product cloth at the initial position of the sewing operation, or when the sewn product cloth is shifted and placed at another sewing operation position, the presser foot is raised. The presser bar is raised and lowered each time by the operation of raising and lowering the lever. Therefore, when raising the presser foot to prepare the sewing product fabric at the initial position of the sewing work, or when shifting the sewing product fabric and placing it at another sewing work position, the presser foot raising / lowering of the presser foot lifting lever is required. In addition to the operation of separating the presser foot from the feed dog by the presser bar and the pressing operation, an operation of lowering the feed dog from the upper surface of the needle plate is required. This also applies to the case where the sewing operation is performed by lowering the presser foot again after lowering the feed dog from the upper surface of the needle plate and raising the feed dog from the upper surface of the needle plate. For this reason, some constructions of the feed dog control mechanism of the sewing machine are disclosed in, for example, Japanese Utility Model Publication No. Sho 62-34536
No.), Japanese Utility Model Publication No. 1-35729, Japanese Patent Laid-Open No. 5-2
No. 77271 discloses this.

[0007] Japanese Utility Model Publication No. 62-34536 (JP-A-59-1984)
No. 174188) discloses a sewing machine remittance control device which is provided between a stroke device for vertically lifting a remittance and a drive shaft. The stroke device has a turning lever pivoted at one end of the shaft. A connecting head is fixed to the shaft in the vicinity of the swiveling lever, and a bell crank rotatably supported on a vertical shaft constantly contacts a cam disk fixed to the drive shaft. And is engaged with the swing lever. In addition, a connecting device is provided for connecting and releasing the turning lever and the connecting head by a connecting pin parallel to the axis of the stroke device.

[0008] According to such a feeder control device for a sewing machine, when the turning lever and the connecting head are connected by the connecting device, the cam disk swings the bell crank when the drive shaft rotates. Since the swing lever swings based on the swing of the bell crank, the connecting head also swings via the connecting pin. By swinging the coupling head, the stroke device imparts a substantially square-shaped movement to the remittance. When the pivoting lever and the coupling head are released by the coupling device, the coupling head does not follow the pivoting lever, so that the remittance can be lowered from the upper surface of the needle plate. Become.

[0009] However, the connecting device of the feeder control device of the sewing machine has to be swung together with the turning lever and the connecting head.
Japanese Patent Application Laid-Open No. 34536/59 (174-188188) does not disclose a swingable technique to the extent that it can be realized.

The feed dog lowering mechanism disclosed in Japanese Utility Model Publication No. 1-372929 has a vertical eccentric cam mounted on an upper shaft, and is connected to a square sesame of an adjusting body via an upper and lower rod. The feed dog is connected via a vertical feed link, a vertical feed arm, and a vertical feed bifurcation, and furthermore, an adjusting body is provided with an adjusting body link and a cam contacting the adjusting body link.

According to such a feed dog lowering mechanism, when the presser lifting push rod interlocking with the presser lift is raised, the cam rotates to push down the adjusting body link, and the adjusting body is rotated to rotate the upper and lower feed link. Since the vertical feed arm and the vertical feed bifurcation are rotated, the feed dog can be lowered.

However, in such a feed dog lowering mechanism, there is a difficulty in assembling, in which it is extremely difficult to set the amount of protrusion of the feed dog from the upper surface of the needle plate. Therefore, the amount of protrusion in use is not fixed, and sewing is unstable. Was likely to occur.

Further, a feed dog lowering device disclosed in Japanese Patent Application Laid-Open No. Hei 5-277271 has a feed base having a feed tooth fixed on an upper surface, and a feed base having one end swingably supported by a machine frame and the other end provided with a feed base. A horizontal feed link hinged to one end of the upper and lower feed arms, one end of which is swingably supported by the machine frame, and an upper vertical feed link one end of which is hinged to the other end of the feed base,
A lower vertical feed link having one end hinged to the other end of the vertical feed arm, a slider having a shaft inserted into each hole formed at the other end of the upper vertical feed link and the lower vertical feed link, and a slider. It has a fulcrum groove block that slidably holds in the vertical direction and a rod that moves forward and backward in the horizontal direction,
The actuator has an end fixed to the fulcrum groove block.

According to such a feed dog lowering device, the hinge connecting portions of the upper and lower vertical feed links move in the horizontal direction in synchronization with the raising of the presser foot at the end of sewing. At the time of the return movement of the feed dog at the first stitch when sewing is resumed, the hinge connection portions of the upper and lower vertical feed links are returned to their original positions, so that the feed dog can be returned.

However, in such a feed dog lowering device, a high processing technique is required for processing the groove for sliding the fulcrum groove block of the slider, which is one factor that increases the manufacturing cost. In addition, since this portion slides, it is severely worn and is apt to cause backlash, so that the durability is deteriorated and the feed force is reduced and noise is generated.

As described above, these conventional feed dog control mechanisms of the sewing machine have many disadvantages in that the mechanism is complicated, expensive parts are required, the production is troublesome, and the durability is poor.

Although the flat stitch sewing machine is not provided with such a feed dog control mechanism, recently, it has become possible to sew thick sewing products such as knits with the flat stitch sewing machine. Before starting the sewing work, raise the presser foot to prepare the sewing product cloth at the initial position of the sewing work, or when shifting the sewing product cloth and placing it at another sewing work position, A need has arisen to lower from the top surface of the needle plate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and provides a sewing machine feed dog retracting device which has a simple and inexpensive component, is easy to manufacture, and has excellent durability. It is an object.

[0019]

According to the present invention, there is provided a feed dog retraction device for a sewing machine, which achieves the above object, by means of a horizontal feed drive unit for making a horizontal feed motion from a drive shaft and a vertical drive unit for making a vertical motion. A feed dog that protrudes from the upper surface of the needle plate in accordance with the above, performs a reciprocating elliptical motion, and a presser foot that separates and presses against the feed dog via a presser bar by a presser raising / lowering operation of a presser lifting lever, A feed dog retraction device for a sewing machine that feeds a cloth by sandwiching a cloth between the feed dog and the presser in a state where the presser is pressed against the feed dog. The vertical movement transmitted to the feed dog in interlock with the presser lifting operation is interrupted, and the feed dog is retracted to the position where it retreats from the upper surface of the needle plate. Feed dog to be transmitted to teeth A configuration in which the dynamic clutch is interposed.

According to the feed dog retraction device of the sewing machine, the position at which the feed dog operating clutch cuts off the vertical movement transmitted to the feed dog by the press-up operation of the press-up lever to retreat the feed dog from the upper surface of the needle plate. The sewing material can be detached between the presser foot and the needle plate without interfering with the feed dog.

Further, in the feed dog retraction device of the present invention, the feed dog operating clutch carries the feed dog, is engaged with the feed base which is connected to the horizontal feed drive unit and is repelled downward, and makes the feed dog move up and down. A swinging member for performing, a driving arm connected to the up-down driving unit and giving a swinging motion to the swinging member, and a meshing clutch member pivotally supported by the swinging member and meshing with the driving arm and repelled in this meshing state. It is preferable that a clutch control lever for releasing and engaging the engagement clutch member with the drive arm in accordance with the lifting / lowering operation of the lifting lever is provided.

According to the feed dog operating clutch constructed as described above, when the presser foot raising lever is pressed down, the clutch clutch member is repelled by the clutch control lever so as to be engaged with the drive arm. The arm can give a swinging motion to the swinging member via the meshing clutch member based on the vertical movement of the vertical driving unit. As a result, the feed base engaged with the swinging member causes the feed dog to move up and down. On the other hand, when the presser-lifting operation is performed, the engaging clutch member is released from the driving arm that has been repelled to the engaged state by the clutch control by the clutch control lever, so that the driving arm applies a swinging motion to the swinging member. Can not be done. Thus, the feed base engaged with the swinging member can maintain the state of being repelled downward, and the feed dog can be retracted to a position retreating from the upper surface of the needle surface.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a feed dog retraction device for a sewing machine according to the present invention will be described below with reference to the drawings, in which a preferred embodiment is applied to a feed dog retraction device for a flat stitch sewing machine.

As shown in FIG. 1, a flat stitch sewing machine to which the feed dog retracting device for a sewing machine of the present invention is applied, for example, two needles 3A, 3
B, one looper (not shown) that reciprocates in an arc so as to intersect with the movement locus of the two needles 3A and 3B, and this looper is disposed below and needles for the two needles 3A and 3B. A needle plate 4 provided with a drop hole, a feed dog 5 that performs an elliptical motion protruding and retreating from the upper surface 4a of the needle plate 4, and a presser lifting lever 45
And a presser foot 6 for holding the sewing material together with the feed dog 5 by operating the presser. In addition, needle clamp 2,
The looper and the feed dog 5 perform respective reciprocating motions by the rotation of the drive shaft 7.

The feed dog 5 includes a main feed dog 5A and a sub feed dog 5B.
(FIGS. 2, 3, 4, and 5), and the cloth is fed by the differential feed mechanism 20. This differential feed mechanism 20 includes a horizontal feed drive unit 200 (FIGS. 2, 3, 4, and 5) that makes a horizontal feed motion from the drive shaft 7, and a vertical drive unit 2000 (that makes a vertical motion from the drive shaft 7). 2, 3, 4, and 6).

The horizontal feed driver 200 is shown in FIGS.
As shown in the figure, the main feed dog 5A and the sub feed dog 5B, which are the feed dogs 5, are fixed to the main feed dog mounting shaft 201 and the sub feed dog mounting shaft 202 so as to move back and forth in the cloth feed direction, respectively. The shaft 201 and the auxiliary feed dog mounting shaft 202 are slidably supported by two support portions 203a and 203b of the feed base 203. A main feed driver 204 and a sub feed driver 205 are fitted on the main feed dog mounting shaft 201 and the sub feed dog mounting shaft 202, and the main feed dog mounting shaft 20 is mounted.
1 is fixed to the main feed driver 204 and the sub feed driver 20
5 is slidable. Similarly, the auxiliary feed dog mounting shaft 202 is fixed to the auxiliary feed driver 205 and is slidable with respect to the main feed driver 204. The feed base 203 supporting these members has a cylindrical boss 203
c, and the base shaft 206
It is supported by. The base shaft 206 is pivotally supported by the machine frame 1 (FIG. 1).

The drive shaft 7 (FIG. 5) is
A horizontal feed cam 207 (FIG. 5) for converting the rotation of the horizontal feed into horizontal motion is fixed, and a horizontal feed rod 208 (FIG. 5) is fitted to the horizontal feed cam 207. One end of the horizontal feed rod 208 is connected to one end 209a of the main feed drive arm 209, and the main feed slide block 210 is provided with two stopper members 21 in a rectangular hole 209b of the main feed drive arm 209.
1, 212 and are slidably supported. The main feed slide block 210 is supported by a swing shaft 213 (FIG. 5) at a portion near the cylindrical boss 203c of the feed base 203. The other end 209 of the main feed drive arm 209
c is the main feed dog mounting shaft 20 via the main feed link 214.
1 is connected to a main feed driving body 204 fixed to the main feed driver 204.

The feed base 203 has a main feed drive arm 2.
A sub-feed slide block 215 (FIG. 5) is supported by a swing shaft 213 on the side opposite to the side on which the sub-feed slide 09 is mounted. The sub-feed slide block 215 has two rectangular holes 216 a of the sub-feed drive arm 216. Stop member 21
7, and 218 are slidably supported. The main feed slide block 210 is attached to the sub feed drive arm 216.
A connecting rod 219 for transmitting the swinging motion of the main feed drive arm 209 is connected. The connecting rod 219 is connected to the main feed driver 204. On the other hand, the upper end 216b of the sub-feed drive arm 216 is connected to the sub-feed driver 2 fixed to the sub-feed dog mounting shaft 202 via the sub-feed link 220.
05.

The horizontal feed drive unit 20 constructed as described above
0, feed feed adjustment dial 2 to adjust the main feed
21 (FIGS. 1 and 5) are provided. The feed adjustment dial 221 is fixed to a substantially semi-disc 223 which can be intermittently moved via a feed dial shaft 222 (FIG. 5). The substantially semi-disc 223 is connected to an adjustment arm 226 via a link 224 and an adjustment plate 225. Are linked. The adjusting arm 226 is the base shaft 20
6 and the arm 226a is connected to one end 209a of the main feed drive arm 209 via an adjustment link 227. In order to adjust the sub feed, the differential adjustment lever 2
28 (FIG. 4) is provided on the right side when viewed from the front of the sewing machine.

As shown in FIG. 6, the differential adjusting lever 228 is formed with an arm 228a, and one end of a differential adjusting link 229 is connected to the arm 228a.
Is rotatably mounted on a predetermined portion. The other end of the differential adjustment link 229 is fixed to one end of a differential adjustment arm 230 capable of intermittent movement, and the differential adjustment arm 230 is supported by the base shaft 206. An adjusting arm 231 (FIGS. 3, 4, and 5) is fixed to the base shaft 206 between the differential adjusting arm 230 and the feed base 203. This adjustment arm 23
The first arm 231a is connected to the lower end 216c of the sub-feed drive arm 216 via the adjustment link 232 (FIG. 5).

The main feed dog 5A and the sub feed dog 5B of the horizontal feed drive unit 200 are provided with a presser foot 6 fixed to the lower end of a presser rod 41 slidably attached to the machine frame 1 described later.
Thus, the cloth can be moved with an appropriate cloth feed amount.

The vertical drive unit 2000 includes an eccentric cam 233 fixed to the drive shaft 7 and converting the rotation of the drive shaft 7 into a vertical motion, as shown in FIGS. One end of the upper and lower rods 234 is fitted. The other ends of the upper and lower rods 234 are, as shown in FIG.
Between the vertical drive unit 2000 driven by the rotation of the drive shaft 7 and the feed dog 5, the vertical movement transmitted to the feed dog 5 in interlock with the pressing operation of the presser lifting lever 45 (FIG. 1) is cut off. A feed dog actuating clutch 1 for retracting the feed dog 5 to a position retreating from the upper surface 4a of the needle plate 4 and transmitting a vertical movement to the feed dog 5 in conjunction with the press-down operation of the press-up lever 45.
Connected to 0.

As shown in FIGS. 2, 3, and 7, the feed dog operating clutch 10 carries the feed dog 5, is connected to the horizontal feed drive unit 200, and engages with the feed base 203 which is repelled downward. Oscillating member 11 that moves up and down on the feed dog 5, a driving arm 12 that is connected to the vertical driving unit 2000 and that oscillates the oscillating member 11,
2 and a clutch control lever 14 for releasing and meshing the meshing clutch member 13 with the drive arm 12 in response to a press-up / down operation of the presser-lifting lever 45. And

The swinging member 11 is rotatably fitted to a mounting shaft 15 having one end fixed to a predetermined portion of the machine frame 1, and an E-ring 17 is attached to a pin 16 protruding from the tip end 11 a. A roller 18 is rotatably mounted. The tip 11a is formed at a position where the swinging member 11 can perform a substantially vertical arc movement when the swing member 11 rotates. A vertical drive arm 19 is provided on the feed base 203 to extract the vertical movement from the swinging member 11 configured as described above. The vertical drive arm 19 is a bent member having an elongated flat portion 19a at the upper end. A part of the bent portion is screwed to the side surface of the feed base 203, and the bent portion at the tip of the flat portion 19a is provided on the swing member 11. Engaged with the roller 18 that has been set. Further, in order to ensure the engagement between the bent portion and the roller 18, a tension spring 235 is stretched between a predetermined portion of the machine frame 1 and the vertical drive arm 19 (FIG. 5). It is urged clockwise (clockwise) about a base shaft 206 pivotally supported at a predetermined position. A tension spring 31 is stretched between the swing member 11 and a predetermined portion of the machine frame 1 and is constantly urged in a counterclockwise direction (counterclockwise). The amount of rotation in the counterclockwise direction is regulated by the pin 32 protruding from the second pin. This allows
It is possible to prevent the vertical drive arm 19 engaged with the roller 18 provided on the swinging member 11 from unnecessarily lowering and colliding with the looper or the like.

One end of the drive arm 12 is rotatably fitted to the mounting shaft 15 so as to overlap the swinging member 11, and the other end is connected to the other end of the upper and lower rods 234. This drive arm 1
A notch 12a is formed at the upper end of the second member 2 so as to be able to mesh with an engagement clutch member 13 described later.

The meshing clutch member 13 has a notch 12a of the drive arm 12 on the side of the swing member 11 where the drive arm 12 overlaps.
One end 13b is pivotally supported to cover the side, for example, the swing member 1
A protruding portion 13 a is rotatably mounted on a pin 33 protruding from a predetermined portion of the drive arm 12 and can mesh with the notch 12 a of the drive arm 12. In addition, the meshing clutch member 13
A tension spring 34 is stretched between the other end 13c of the swing member 11 and a predetermined portion of the swing member 11, and the meshing clutch member 13 is always clocked around a pin 33 projecting from the swing member 11. It is designed to bias in the direction. As a result, the projection 13a of the dog clutch member 13 and the notch 1 of the drive arm 12 are formed.
2a is engaged with the meshing clutch member 13
And the drive arm 12 can be held in an engaged state.

The clutch control lever 14 is connected to the swing member 11
And is rotatably fitted to the mounting shaft 15. At one end of the clutch control lever 14, an arm portion 14a is formed which comes into contact with the other end 13c of the dog clutch member 13 when the clutch control lever 14 rotates counterclockwise. The clutch control lever 14 has a presser lifting lever 45 described later.
The wire hook 14b is formed so that one end of the interlock wire 35 for retracting the feed dog interlocked with the press-up / down operation can be hooked. Further, a torsion spring 36 (FIG. 7) is superimposed on the clutch control lever 14 and is rotatably fitted to the mounting shaft 15. This torsion spring 36
Is engaged with a wire hook 14b of the clutch control lever 14, and the other arm 36b is
7 is hung on a predetermined portion. Therefore, since the clutch control lever 14 is constantly urged clockwise by the resilience of the torsion spring 36, the arm 14
“a” is in a non-contact state with the other end 13 c of the dog clutch member 13. The other end of the mounting shaft 15 is fixed to a mounting plate 37 fixed to a predetermined portion of the machine frame 1.

As shown in FIG. 1, the presser foot 6 is fixed to the lower end of a presser bar 41 mounted on the machine frame 1 so as to be vertically movable, and a presser bar rod 42 is fixed to a predetermined position of the presser bar 41. ing. The presser rod 42 is provided so as to be wound around the presser rod 41 above the presser rod 42.
The presser foot 6 is pressed against the upper surface 4a of the needle plate 4 by the pressing force of the presser spring 44 whose elasticity is adjusted by the presser adjusting screw 43 screwed to the upper end of the needle plate 4. Also, presser rod 4
2, a cam of a presser lifting lever 45 rotatably mounted on the machine frame 1 is engaged, and when the presser lifting lever 45 is pressed, the presser rod 42 is raised and the presser foot 6 is fed. When the presser lift lever 45 is pressed down from this state, the presser rod 42 is lowered and the presser foot 6 is pressed against the feed dog 5.

An interlocking mechanism for interlocking the feed dog retracting interlocking wire 35 hooked on the clutch control lever 14 of the feed dog operating clutch 10 based on the presser lifting / lowering operation of the presser lifting lever 45 is attached to the presser bar rod 42. 50 are engaged. The interlocking mechanism 50 is slidably supported vertically at a predetermined portion of the machine frame 1, and has a lower end 51 b formed in an L-shape, and an engaging arm 51 inserted between the presser bar rod 42 and the presser lifting lever 45. A U-shaped guide 53 which is fixed to one end of an interlocking shaft 52 which is engaged with a pin 51 a protruding from the engagement arm 51 and is supported at a predetermined portion of the machine frame 1;
A wire hook 54 fixed to the other end of this interlocking shaft 52 and capable of hooking the other end of the interlocking wire 35 for retracting the feed dog.
It is composed of Note that the feed dog retracting interlocking wire 35 is wound around and stretched around pulleys 55 and 56 so as to be able to move smoothly within the machine casing 1.

The interlocking mechanism 50 is driven by the presser lifting / lowering operation of the presser lifting lever 45 and the presser bar
At the same time, the engagement arm 51 moves up and down, so that the U-shaped guide 53 engaged with the pin 51a of the engagement arm 51 rotates the interlocking shaft 52, and the wire hook 54 fixed to the interlocking shaft 52 feeds. The tooth retracting interlocking wire 35 is pulled or loosened. Thereby, the feed dog operating clutch 10 can be operated by the feed dog retracting interlocking wire 35.

The operation of the feed dog retracting device of the sewing machine in the thus configured flat stitch sewing machine will be described with reference to FIGS. 9, 10, 11, and 12 as appropriate.

First, in order to prepare the sewn product cloth at the initial position of the sewing operation, or to shift the sewn product cloth and place it in another sewing operation position, the presser foot lifting lever 45 is pressed and the presser foot 6 is operated. To rise.

The press-up operation of the press-up lever 45 raises the presser rod 42, and the interlocking mechanism 50 engaged with the presser rod 42 pulls the interlock wire 35 for retracting the feed dog. . When the feed dog retracting interlocking wire 35 is pulled, the clutch control lever 14 of the feed dog operating clutch 10 rotates counterclockwise against the resilience of the torsion spring 36. The portion 14a is the other end 13c of the dog clutch member 13.
Is pushed up against the elasticity of the tension spring 34. As a result, the projection 13a of the dog clutch member 13
Is disengaged from the notch 12a of the drive arm 12, so that the dog clutch member 13 can be released from the drive arm 12 (FIG. 9).

The rocking member 11 is in a freely rotatable state by the clutch releasing operation of the feed dog operating clutch 10. Rotate counterclockwise until it touches. Therefore, even if the feed dog 5 before the clutch operation protrudes from the upper surface 4a of the needle plate 4, the roller 18 provided on the swinging member 11 moves downward while performing an arcuate movement. The vertical drive arm 19 engaged with the roller 18 is lowered while rotating clockwise around the base shaft 206 (FIGS. 3 and 4) by the elastic force of the tension spring 235. The needle plate 4 can be retracted to a position retreating from the upper surface 4a (FIG. 9).

Thus, before the sewing operation is started, the presser foot 6
The feed dog 5 is lowered from the upper surface 4a of the needle plate 4 when the sewing product cloth is prepared at the initial position of the sewing operation by moving the sewing product cloth or when the sewing product cloth is shifted to another sewing operation position. Eliminates the need.

In the state where the dog clutch member 13 is released from the drive arm 12, even if the drive shaft 7 rotates,
Since the vertical motion of the vertical drive unit 2000 of the differential feed mechanism 20 is not transmitted to the swing member 11, the horizontal feed drive unit 2
The feed dog 5 does not project from the upper surface 4a of the needle plate 4 even if the upper and lower drive arms 19 are reciprocated horizontally by the horizontal feed motion of 00.

In this manner, the feed dog 5 is connected to the upper surface 4 of the needle plate 4.
a, the sewing material is prepared at the initial position of the sewing operation, or the sewing material is shifted to another sewing operation position, and then the presser foot raising lever 45 is pressed down and the presser foot is lowered. 6 is lowered to press the sewn material on the needle plate 4.

Since the presser bar 42 is lowered by the pressing operation of the presser raising lever 45, the interlocking mechanism 50 engaged with the presser bar 42 relaxes the interlock wire 35 for retracting the feed dog. Become. When the interlock wire 35 for retracting the feed dog is relaxed, the clutch control lever 14 of the feed dog operating clutch 10 rotates clockwise due to the elasticity of the torsion spring 36.
The fourth arm 14a is disengaged from the other end of the dog clutch member 13, and the dog clutch member 13 rotates clockwise by the elastic force of the tension spring. As a result, the projection 13a of the dog clutch member 13 fits into the notch 12a of the drive arm 12, so that the dog clutch member 13 can be meshed with the drive arm 12 (FIG. 10).

Since the pivoting member 11 is in a state where the rotation is restricted by the clutch transmitting operation of the feed dog operating clutch 10, the pivoting member 11 is driven by the driving arm 12.
Swing motion. Therefore, the drive arm 12 gives a swinging motion to the swinging member 11 by the vertical movement by the vertical drive unit 2000 of the differential feed mechanism 20, and the horizontal feeding drive unit The upper and lower drive arms 19 by the horizontal movement by 200
, A reciprocating horizontal feed motion is provided, so that the feed dog 5 can perform an elliptical motion that protrudes and retreats from the upper surface 4a of the needle plate 4 in accordance with the vertical motion (FIGS. 10, 11, and 12).

When the sewing operation is started in this state, the drive shaft 7 is rotated, so that the feed dog 5 is moved by the horizontal feed drive unit 200 that makes a horizontal feed motion from the drive shaft 7 and the vertical drive unit 2000 that makes the vertical motion. The two needles 3A and 3B fixed to the needle holder 2 are moved up and down linearly in conjunction with the elliptical movement of the feed dog 5 by performing an elliptical movement protruding and retreating from the upper surface 4a of the needle plate 4 in accordance with the vertical movement. The looper reciprocates and the looper reciprocates in an arc so as to intersect with the movement locus of the two needles 3A and 3B. Thereby, the sewn product fabric can be sewn.

According to a preferred embodiment of the feed dog retracting device of the sewing machine of the present invention, the feed dog having the swing member 11, the drive arm 12, the meshing clutch member 13 and the clutch control lever 14 as described above. Working clutch 1
Although 0 is used, the present invention is not limited to this, and a structure and configuration that can be easily changed by those skilled in the art without departing from the technical scope of the feed dog operating clutch 10 may be used.

[0052]

As is apparent from the above description, according to the feed dog retracting device of the sewing machine of the present invention, the mechanism is constituted by simple and inexpensive parts, and the manufacturing is easy and the durability is excellent. It will be. Further, the feed dog is forcibly lowered when the presser foot is raised, and is returned at the time of the return movement of the first stitch feed tooth when sewing is resumed. Even without damaging the cloth. Also, when removing and attaching the cloth when the presser foot is raised, since the feed dog is retracted from the upper surface of the needle plate,
The cloth will not be caught on the tip of the feed dog and will not be damaged.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall image of a flat stitch sewing machine to which a feed dog retraction device of the present invention is applied.

FIG. 2 is a side view of a main part showing a preferred embodiment of a feed dog retraction device of the sewing machine of the present invention.

FIG. 3 is a main part top view showing a preferred embodiment of a feed dog retraction device of the sewing machine of the present invention.

FIG. 4 is an exploded perspective view showing an entire differential feed mechanism and a feed dog operating clutch related to the feed dog retraction device of the sewing machine of the present invention.

FIG. 5 is an exploded perspective view showing details of a horizontal feed drive unit of the differential feed mechanism.

FIG. 6 is an exploded perspective view showing a mechanism relating to a differential adjustment lever for adjusting sub-feed by the differential feed mechanism.

FIG. 7 is an exploded perspective view showing details of a vertical drive unit and a feed dog operating clutch of the differential feed mechanism.

FIG. 8 is a block diagram showing a relation of each mechanism of the feed dog retraction device of the sewing machine of the present invention.

FIG. 9 is an explanatory view showing a retracted state of the feed dog by the feed dog retracting device of the present invention.

FIG. 10 is an explanatory view showing a feed dog operation state by the feed dog retraction device of the present invention.

FIG. 11 is an explanatory view showing a feed dog operation state by the feed dog retraction device of the present invention.

FIG. 12 is an explanatory view showing a feed dog operation state by the feed dog retraction device of the present invention.

[Explanation of symbols]

 4 Needle plate 4a Upper surface of needle plate 5 Feed dog 6 Presser foot 7 Drive shaft 10 Feed dog Operating clutch 11 ····· Swinging member 12 ······ Driving arm 13 ····· Meshing clutch member 14 ····· Clutch control lever 41 ······· Presser bar 45 ···・ Lift lifting lever 200 ・ ・ ・ ・ ・ ・ ・ Horizontal feed drive unit 203 ・ ・ ・ ・ ・ ・ ・ Feed base 2000 ・ ・ ・ ・ ・ ・ ・ Vertical drive unit

Claims (2)

[Claims] 1. An upper surface (4a) of a needle plate (4) according to the vertical movement by a horizontal feed drive (200) for producing a horizontal feed movement from a drive shaft (7) and a vertical drive (2000) for producing a vertical movement. ), And a presser foot which separates and presses the feed dog via a presser bar (41) by a presser raising / lowering operation of a presser lifting lever (45). (6) a feed dog retraction device of a sewing machine for feeding a cloth by sandwiching a cloth between the feed dog and the presser in a state where the presser is pressed against the feed dog, Between the portion and the feed dog, the vertical movement transmitted to the feed dog in interlock with the press-up operation of the press-up lever is cut off to a position where the feed dog retreats from the upper surface of the needle plate. Evacuate the presser foot presser lever A feed dog retraction device for a sewing machine, wherein a feed dog operating clutch (10) for transmitting the vertical movement to the feed dog in conjunction with the lowering operation is interposed. 2. The feed dog operating clutch carries the feed dog and is connected to the horizontal feed drive unit and engages with a downwardly repelled feed base (203) to apply the vertical movement to the feed dog. A swinging member (11) for performing swinging motion of the swinging member connected to the up-down driving unit;
A meshing clutch member (13) pivotally supported by the swing member and meshing with the drive arm and repelled in this meshing state; and the meshing clutch member in response to a press-up / down operation of the presser-lifting lever. 2. The feed dog retracting device of the sewing machine according to claim 1, further comprising a clutch control lever (14) for releasing and meshing with the drive arm.