JPH078655A - Fabric holding-down apparatus for stitch forming machine - Google Patents

Abstract

PURPOSE: To match the position during sewing of a spring for generating the pressurizing force of a cloth presser foot with the thickness of a sewing material and to prevent the generation of reacting force at the time of the elevating/ lowering motion of a cloth presser bar on the other hand. CONSTITUTION: Upper and lower supporting elements 40 and 42 are provided movably in the longitudinal direction of the cloth presser bar 38, and one of both supporting elements 40 and 42, favorably the upper supporting element 40, is connected to a driving mechanism 31. The driving mechanism 31 can be fixed to the position corresponding to the area of the work position of the cloth presser foot 51. The other supporting element 42 is used for supporting the cloth presser foot 51 and brought into frictional contact with a supporting member 43 carried by the cloth presser bar 37 or connected to the cloth presser bar 38 by the spring 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stitch having a spring arranged between two supporting elements to generate a pressing force of a presser foot and a drive mechanism for moving a presser bar up and down. The present invention relates to a cloth pressing device for a forming machine.

[0002]

2. Description of the Related Art In a cloth pressing device for a stitch forming machine, which is known from German Patent Publication No. 3217826,
A position adjusting bush fixed to the sewing machine casing and a clamp serving as a supporting element that is fixed to the presser bar and supports a spring for generating power transmitted to the presser foot are provided. A hand lever is rotatably supported by the casing for driving the presser bar to move up and down. An angle lever is connected to the hand lever for transmitting a vertical motion to a fork member engaged with the clamp from below. The spring is compressed when the fork member is lifted, and thus when the pressure foot is lifted, while the spring is relaxed when the pressure foot is lowered.

A force for compressing the spring is required to lift the cloth presser bar, and a force to counteract the force released by the relaxation of the spring must be generated when lowering the presser bar. A considerable amount of work is required of the operator to raise and lower the rod.

FIG. 11 of Japanese Examined Patent Publication No. 60-40875 shows a drive mechanism for raising and lowering the cloth pressing device. In this case, the work clamp foot is not elastically supported by the work clamp device. The presser foot is rotatably supported and is connected to a drive mechanism via a link device. The drive mechanism rotates the presser foot by 90 °. The presser foot is surrounded by an arcuate shield member having a guide groove that extends obliquely along the rotation path, and has a pin that engages with the guide groove. Since the guide groove extends obliquely, the pin lifts or lowers the presser foot according to the direction of its rotation.
The lifting or lowering distance is given by the slope of the guide groove.

Since the spring does not react to the lifting motion of the cloth presser foot, it can be moved with a slight force in the lifting direction. However, since it is not elastically supported, the cloth presser foot with respect to the sewn product is lowered. The deflection movement cannot be performed.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to adapt the position of a spring for generating a pressing force of a cloth presser foot during sewing to the thickness of a sewn product, while raising and lowering a cloth presser bar. In this case, a fabric pressing device of the type mentioned at the beginning is constructed so that no reaction force is generated in this case.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides both support elements movably in the longitudinal direction of the presser bar, one of the support elements being preferably the upper support element. Is coupled to the drive mechanism, the drive mechanism being fixable in a position corresponding to the region of the working position of the foot foot, another supporting element being used to support the foot foot, and by a spring, It is characterized in that it is in frictional contact with a supporting member which is carried by the presser bar or connected to the presser bar.

Embodiment 1 describes an embodiment of the lower support element, which, due to such an advantageous embodiment, provides the lower support element with a support which is as simple as possible in addition to its original function. It also has a function of preventing the member from being displaced.

Embodiment 2 describes an advantageous embodiment of the drive mechanism. Since the guide extends obliquely, a vertical motion component is superimposed on the motion of the position adjusting member that is performed only in the horizontal direction, and this vertical motion component is transmitted to the work clamp bar via the driver. On the other hand, the upper support element can also be used as a stationary support member, since the driver frictionally contacts the upper surface of the guide.

Embodiment 3 discloses how to drive the position adjusting member to lift the cloth pressing rod and how to return the position adjusting member to its starting position to lower the cloth pressing rod. There is.

According to the construction of the fourth aspect, the effect that the position of the presser foot can be adjusted steplessly in order to adjust the level of the presser foot to the thickness of the sewn product is obtained. To be

According to the construction of the fifth aspect, the work clamp bar moves only in a preset direction during the lifting motion.

When the thickness of the sewn product changes due to the work clamp foot according to the sixth embodiment, which is softer than the spring (in this case, the work clamp foot does not reach the stopper), during the sewing process. The effect is that the lower support element does not move with respect to the work clamp bar, so that the work clamp foot can follow the surface of the sewn material without inertia. Such a construction of the cloth pressing device is very effective especially for a lower cloth and another cloth, for example, a sewn product in which a retaining ring of a pocket or a belt is sewn together. This is because the thickness of the sewn product changes due to the additional cloth, and this change is usually smaller than the range of motion of the work clamp up to the stopper.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The casing 1 of the sewing machine shown in FIG.
It is composed of a substrate 2, a stand 3, an arm 4 (FIG. 2), and a head 5. Inside the head 5, a needle bar 6 carrying a needle 7 and driven in a known manner is arranged.

The casing 1 has an intermediate floor plate 8.
A position adjusting device 9 is arranged on the intermediate floor plate 8. The position adjusting device 9 has a sleeve 10 as shown in FIG. The sleeve 10 is rotatably supported by a pin 11 inserted into the intermediate floor plate 8 and surrounds the bush 12. The bush 12 is supported by a spring element 13 housed in the sleeve 10. The bush 12 has a horizontal hole, and the end of this hole is the long hole 14 of the sleeve 10.
Is aligned with. A pin 15 is inserted in the hole. The pin 15 engages with the elongated hole 14 and carries the position adjusting means 16 housed in the bush 12. The position adjusting means 16 is configured so that the cross section in the area of the casing cover 17 is square. The casing cover 17 has a square opening for preventing the position adjusting means 16 from rotating.

A pin is integrally formed on the upper end of the square portion of the position adjusting means 16. A flat surface 18 is formed on the pin. Since the surface 18 is flat, this pin prevents rotation of the alignment button 19 fixed to it.

The sleeve 10 is provided with an external thread, on the external thread of which the position adjusting member 2 is located in the region between the fixing rings 20 and 21.
2 are arranged. Both fixing rings 20 and 21 limit the position adjusting path with respect to the position adjusting member 22. The position adjusting member 22 has a guide groove 23 extending obliquely on the outer peripheral surface thereof. A tension spring 24 fixed to the casing 1 is engaged on one side with the outer peripheral surface of the position adjusting member 22, and a connecting rod 25 is engaged on the other side. The opposite end of the connecting rod 25 is pivotally attached to the link rod 26 as shown in FIG. The link rod 26 is rotatably supported by a pin 27 supported by the intermediate floor plate 8. The tension spring 2 is attached to the link rod 26.
One end of 8 is engaged, and the other end of the tension spring 28 is fixed to a cylinder 29 forming a driving means. The free end of the piston rod 30 of the cylinder 29 is in contact with the link rod 26.

The drive mechanism 31 is constituted by the components 9 to 30.
Is formed.

The pin 3 is inserted in the guide groove 23 of the position adjusting member 22.
2 is engaged. The pin 32 is formed integrally with the cylindrical carrier 33. A second pin 34 aligned with the pin 32 is integrally formed on the carrier 33. A support member 35 is fixed to the intermediate floor plate 8 on the pin 34 side. The support member 35 has a vertically elongated hole 36 for receiving the pin 34.

The carrier 33 corresponds to the support bush 3 according to FIG.
It has a hole with an internal thread for receiving the threaded upper part of the work clamp bar 38 which is movably guided in 9. The carrier 33 is used as a support element 40 for supporting the end of the spring 41 provided on the presser bar 38 which is in contact with the shoulder of the presser bar 38. Spring 4
The other end of 1 is in contact with the second support element 42. This second
The supporting element 42 of the above is movably arranged on the lower portion of the presser bar 38, and is supported by the supporting member 43. The support member 43 is configured as a nut that is rotated along the screw of the lower portion of the presser bar 38 and is housed between the arms 44 of the support element 42 so as not to rotate.
In the following, the support element 40 will be called the upper support element and the support element 42 will be called the lower support element. Cloth holding bar 38
Has a slit 45 (FIG. 4) at its upper end for engaging a driver. When the presser bar 38 rotates, the presser bar 38 and the support member 43 for preventing rotation are connected by a screw, so that relative movement occurs between the presser bar 38 and the support member 43, so that the cloth Presser bar 38
There is also relative movement between the lower support element and the lower support element. The end of the spring 41, which is in contact with the shoulder of the presser bar 38, is lifted or lowered depending on the direction of rotation during this rotational movement, so that the pretensioning force of the spring 41 changes. The other end of the spring 41 is not displaced.

The lower support element 42 has a passage. A cloth pressing foot sleeve 47 guided in a vertical support bush 46 is fixed in the passage. The upper portion of the presser foot sleeve 47 is provided with an internal thread, and a screw pin 48 is attached to the internal thread. Screw pin 48
Is used to adjust the pretension of the work clamp foot spring 49 in contact with the lower surface thereof. The spring constant of the presser foot spring 49 is considerably smaller than that of the spring 41, and the presser foot spring 49 acts on the presser foot shaft portion 50 of the presser foot 51.

The cloth presser foot shaft portion 50 is composed of the cloth presser foot sleeve 4
It carries a clamp 52 which is engaged in the recess 53 of the No. 7. The ridge forming the boundary wall of the recess 53 of the presser foot sleeve 47 is used as a stopper 54 for limiting the movement of the presser foot shaft 50, like the lower ridge of the presser foot sleeve 47. To be

The components 32 to 52 are the cloth pressing device 55.
Is formed.

Next, the operation of the cloth pressing device according to the present invention will be described.

During the sewing process, the work clamp bar 38 is in the position shown in FIG. The piston rod 30 of the cylinder 29 runs into the cylinder 29, as shown in FIG. 3, so that the link rod 26, which is pulled towards the piston rod 30 by the tension spring 28, occupies the right reverse position. Since the position adjusting member 22 connected to the link rod 26 by the connecting rod 25 is connected to the cylinder 29 so as not to rotate, the tension spring 24 is held at a position where it is slightly pulled. The pin 32, which is connected to the presser bar 38 via the upper support element 40, engages the lower end of the guide groove 23.

To lift the work clamp rod 38, the cylinder 29 is controlled so that the piston rod 30 runs. The piston rod 30 pushes the link rod 26 to the left reverse position in FIG. The pivoting movement of the link rod 26 to the left is transmitted to the position adjusting member 22 via the connecting rod 25, so that it pivots together against the action of the tension spring 24.

Due to the rotational movement of the position adjusting member 22, the guide groove 23 moves relative to the pin 32. In this case, since the guide groove 23 extends obliquely, the vertical motion component is superposed on the horizontal component of the position adjusting member 32, and the presser bar 38 is inserted through the pin 32 and the upper support element 40.
Be transmitted to. Since the pin 34 is guided in the slot 36 of the support member 35, the upper support element 40 is prevented from rotational movement about its longitudinal axis, so that the upper support element 40 has a vertical component of movement. It is merely converted into the movement of the presser bar 38. The position adjusting member 22 is held by the cylinder 29 in such a position that the pin 32 comes into contact with the upper end hand of the guide groove 23 when the piston rod 30 has completely run out of the cylinder 29.

The spring 41 is provided during the sewing process and for the presser bar 3.
When 8 is lifted, it works as follows.

The vertical position of the work clamp foot 51 when the work clamp foot 51 is in the operating position is set as follows, that is, when the thickness of the sewn product changes slightly (at this time, The clamp 52 fixed to the work clamp foot shaft portion 50 does not reach the upper stopper 54), only the work clamp foot spring 49 is deformed, while the lower support element 42 moves the upper support element 40 via the work clamp rod 38. Support member 4 drivingly coupled with
It is set not to leave 3. As the sewn product passes through the thicker part than the other part, the clamp 52 abuts the upper stop 54, so that the lower support element 40 moves away from the support member 43.

If the lifting of the presser bar 38 is to be carried out at a place of normal thickness, both support elements 40 and 42 are to be supported.
Carry out the same movement, so that the tension of the spring 41 is constant. Therefore, the power provided by the drive mechanism 31 is independent of the spring constant of the spring 41. On the other hand, if the work clamp bar 38 needs to be lifted at a place where the material to be sewn is excessively thick, and therefore the lower support element 40 needs to be moved away from the support element 42. The lower support element 42 is separated from the upper support element 40 until it reaches the support member 43, by virtue of the action of the spring 41 whose load has been reduced to a set pretensioning force during the lifting process. When the lower support element 42 contacts the support member 42, the lower support element 42 follows the movement of the presser bar 38 and thus the upper support element 40.

In order to lower the work clamp rod 38, the piston rod 3
0 runs into the cylinder 29 again. The tension spring 28 causes the link rod 26 to return and rotate to its starting position, and since the link rod 26 is connected to the position adjusting member 22, the position adjusting member 22 also returns and rotates to its starting position. The return rotation of the position adjusting member 22 is assisted by the tension spring 24. When the position adjusting member 22 reaches its end position, the pin 32 is located at the lower end of the guide groove 23.

Unlike the embodiment described above, the upper support element 40 is movably mounted on the pressure foot rod 38.
Supporting the drive mechanism 31 with the upper support element 40 and the presser bar 38, and the upper support element 40 is lifted earlier than the presser bar 38 in the initial stage of the lifting motion.
Therefore, it is also advantageous to configure it so that it can be lifted faster than the lower support element 42. The force that is released when the spring 41 relaxes facilitates the lifting of the presser bar 38.

The descending movement of the presser bar 38 as it descends is damped by the tension of the spring 41.

Next, the embodiments of the present invention will be listed.

(1) The lower support element (42) serves to prevent rotation of the support member (43) which is arranged in the threaded part of the work clamp bar (38) and which is equipped with an internal thread. The cloth pressing device for a stitch forming machine according to claim 1, wherein

(2) The drive mechanism (31) has a position adjusting device (9) provided with a position adjusting member (22), and the position adjusting member (22) is entrained on the upper support element (40). Guides (23) that guide the body (32) and extend diagonally
And having relative movement with respect to the entrainment body (32), the entrainment body (32) is guided by the action of the supporting force of the spring (41) when the presser foot (51) is in the working position. The cloth pressing device for a stitch forming machine according to claim 1, wherein the cloth pressing device is supported on the upper surface of (23).

(3) The position adjusting member (22) is held at its starting position by the tension spring (24), and the position adjusting member (22) is deflected from its starting position via the transmissions (25, 26). The cloth pressing device for the stitch forming machine according to the above item (2), characterized in that it is connected to a driving means (29) for causing it.

(4) The position adjusting device (9) has an elastic element (1
3) A carrier having position adjusting means (16) supported by 3), the position adjusting means (16) having a male screw for engaging a position adjusting member (22) having a female screw. (10) A presser foot device for a stitch forming machine according to the above item 2 or 3, which is drivingly connected to the presser foot device.

(5) The work clamp bar (38) is connected to the guide element (3).
4), the guide element (34) is connected to the support member (3).
5. The presser foot device for a stitch forming machine according to claim 1, characterized in that it is engaged with a guide (36) formed in 5) and extending in the direction of movement of the presser foot rod (38).

(6) A cloth presser foot spring (49) having a small elastic constant is provided, and the cloth presser foot spring (49) supports the cloth presser foot (51) until it reaches a stopper, and supports the lower part. 2. Presser foot device according to claim 1, characterized in that the element (42) serves as a support member for the foot foot spring (49).

[0042]

According to the present invention, since the two support elements can be moved, both the support elements can be moved to different positions by the same movement when the cloth pressing rod is moved up or down, or they can be moved relative to each other. However, it can be determined in advance whether to move to the other position. Moving both support elements in the same movement can prevent the spring from deforming in this direction of movement. Therefore, when lifting the presser bar, it is only necessary to overcome the weight of the components of the presser device that are lifted with the presser bar and the forces generated by the friction that counteracts the movement of these components.

When the two supporting elements are driven while moving relative to each other, the upper supporting element is lifted faster than the lower supporting element, and the spring relaxation that occurs at this time assists the lifting process at the beginning of the lifting movement. It is advantageous to do so. This interrupts the pre-tensioning of the spring, which must be re-tensioned when lowering the work clamp, the force for which is reduced by gravity.

Since one of the two support elements is operatively connected to a drive mechanism which can be fixed in a position corresponding to the region of the working position of the work clamp, this one support element is immobile during the sewing process and thus It can be used as a supporting member for absorbing the supporting force of a spring. The basic position of the work clamp is usually set by the level of the needle plate, and the movement from this basic position is directed upwards, so by connecting the upper support element with the drive mechanism, It is possible to prevent the turning of the force flow when transmitting the supporting force to.

Unlike the upper support element, the lower support element, which is also used to support the work clamp foot, is movable during the sewing process, and thus, for example, when the thickness of the sewn product changes. The movement of the foot can be transmitted to the spring.

[Brief description of drawings]

FIG. 1 is a side view of a sewing machine provided with a cloth pressing device according to the present invention.

2 is a cross-sectional view taken along the line II-II in FIG.

3 is a cross-sectional view taken along the line III-III in FIG.

FIG. 4 is an enlarged cross-sectional view of a position adjusting device of a drive mechanism for the cloth pressing device.

[Explanation of symbols]

 31 Drive Mechanism 38 Cloth Bar Rod 40 Upper Support Element 41 Spring 42 Lower Support Element 43 Support Member

Front page continued (72) Inventor Kurt Formal Germany F. Day 6751 Weilerbach Bergstraße 4

Claims (1)

[Claims] 1. A spring (41) arranged between two support elements (40, 42) for generating a pressing force of a presser foot (51) and a drive for raising and lowering a presser bar (38). In a presser foot device of a stitch forming machine having a mechanism (31), both support elements (40, 42) are provided movably in the longitudinal direction of the presser foot rod (38), and both support elements (40, 42) are provided. 42) one of the upper support elements (40) is preferably connected to said drive mechanism (31), said drive mechanism (31) being fixed in a position corresponding to the region of the working position of the work clamp (51) Yes, another support element (42) is used to support the foot foot (51) and by said spring (41)
It is carried by the presser bar (38) or the presser bar (3
8) A presser foot device for a stitch forming machine, which is in frictional contact with a support member (43) connected to 8).