CN114466953A

CN114466953A - Fabric feeding device for sewing machine

Info

Publication number: CN114466953A
Application number: CN202080069597.9A
Authority: CN
Inventors: C·圭雷斯基
Original assignee: Vi Be Mac SpA
Current assignee: Vi Be Mac SpA
Priority date: 2019-10-01
Filing date: 2020-09-30
Publication date: 2022-05-10
Also published as: WO2021064582A1; JP2022554072A; EP4038229B1; MX2022003953A; US20220389632A1; EP4038229A1

Abstract

A fabric feed device for a sewing machine is disposed adjacent to one or more sewing needles and is adapted for movement of a jaw.

Description

Fabric feeding device for sewing machine

Technical Field

The present invention generally relates to a fabric feeding device for a sewing machine. More specifically, it is a fabric feeding device for one or more sewing machine needles.

Background

It is known that in sewing machines, below one or more sewing needles, jaws are arranged, designed to advance two pieces of fabric during their sewing.

Fabric feeding devices are known from patent documents US3611817A, US5309854A, CN 108589061A.

The jaws have an elongated shape and include projections that attach to the fabric to advance it. For this purpose, the jaws perform a helical movement, so as to always remain in a substantially horizontal position.

A problem with the jaws and fabric feed devices according to the prior art is that one of the two fabric pieces being sewn, particularly the upper one, is essentially braked by the presser foot.

As a result, the jaws move the lower fabric sheet and damage the upper fabric sheet.

In other words, the upper and lower sheets will have different strokes during sewing, which may cause the upper fabric to ripple after sewing.

To overcome this problem, the operator must move the upper fabric sheet faster. As a result, the goodness of the stitch may vary depending on the skill and experience of the operator.

Disclosure of Invention

The object of the present invention is to provide a fabric feeding device for a sewing machine which ensures uniform movement of a lower fabric piece and an upper fabric piece at the time of sewing.

Another object of the present invention is to provide a fabric feeding device which ensures an optimal movement of the upper fabric sheet irrespective of the pressure of the presser foot and the different movement speeds of the lower fabric sheet.

Another object of the present invention is to provide a fabric feeding device capable of improving the sewing quality, obtaining uniform sewing of a sewing fabric piece, regardless of the action of the operator on the sewing machine.

These and other objects are achieved according to the present invention by a fabric feeding device for a sewing machine, comprising a first rod to one end of which a first jaw is fixed, at the opposite end of which a first U-shaped body is provided, opening downwards.

In the first lever, there is provided a first elongated seat in which a square pivot is housed, the square pivot serving as a fulcrum of the first lever and as a slider so that the first lever can move according to horizontal swinging and translating movements.

Also included is a rotation pin to which a first cylindrical body is attached and with which a first cylinder eccentric with respect to the axis of the pin is associated, the first cylinder being housed in a respective cylindrical seat obtained in a first square block to move vertically in a first U-shaped body.

The feed device according to the invention is characterized in that it comprises a second lever, at one end of which a second jaw is fixed.

At the opposite end of the second rod there is a second U-shaped body opening towards the rear of the second rod and a third U-shaped body opening downwards.

In the second lever, there is a second elongated seat in which a square pivot is housed, acting as a fulcrum of the second lever and as a slider, so that the second lever can move according to horizontal oscillating and translating movements.

It comprises a second cylindrical body fixed to the rotation pin and associated with it a second cylinder eccentric with respect to the axis of the pin, which is housed in a corresponding cylindrical seat formed in a second square designed to move vertically in a third U-shaped body, an eccentric cylindrical element contained and fixed to the rotation pin, housed in a cylindrical seat formed in a third square designed to move horizontally in the second U-shaped body.

With this configuration, since the third block can only move horizontally inside the second U-shaped body, the eccentric cylindrical element, in its movement, moves the second arm vertically and therefore also the first arm.

Similarly, since the first square block can only move vertically in the first U-shaped body, the second square block can only move vertically in the third U-shaped body, the first cylinder moves the first rod horizontally, and the second cylinder moves the second rod horizontally.

By varying the eccentricity of the cylinders relative to their respective cylindrical bodies, the stroke of these latter two displacements can be varied independently of each other.

Advantageously, the parallelepiped block attached to the first rod can be received and slid into an elongated seat in the second rod, so that the second rod can move horizontally relative to the first rod, and any other relative movement between the first and second rods is prevented.

Furthermore, the parallelepiped block may be attached to the second rod by a plate so that the first rod does not move away from the second rod.

The position of the first cylinder relative to the first cylindrical body is adjustable so as to vary the eccentricity of the first cylinder relative to the rotation pin and therefore the stroke of the first rod in the horizontal direction.

This adjustment can be performed by means of a first adjusting screw.

Similarly, the position of the second cylinder relative to the second cylindrical body may be adjustable so as to vary the eccentricity of the second cylinder relative to the rotation pin and thus the stroke of the first rod in the horizontal direction.

This adjustment can be performed by means of a second adjusting screw.

Drawings

Further features and details may be better understood from the following description, given as a non-limiting example, and from the attached drawings:

FIG. 1 is an isometric view of a sewing machine including a fabric feeding device according to the present invention;

figures 2 and 3 are side isometric views of a fabric feeding device according to the invention;

figure 4 is an exploded isometric view of a fabric feeding device according to the present invention.

Detailed Description

Referring to the drawings, a fabric feeding device provided in an arm B of the sewing machine shown in fig. 1 is indicated by 10.

The feeding device 10 comprises a first rod 12 and a second rod 14.

A set of jaws 16 and a single jaw 18 are attached to one end of the first lever 12 and one end of the second lever 14, respectively.

At the opposite end of the first lever 12 and at the opposite end of the second lever 14, there are arranged a first U-shaped body 20 open downwards and a second U-shaped body 22 open towards the rear of the second arm 14, respectively.

A third U-shaped body 24, open downwards, is connected to the second U-shaped body 22 by means of two connecting screws 23.

The first rod 12 and the second rod 14 have a first seat 26 and a second seat 28, respectively, in which a square pin 30 is inserted to be constrained to the sewing machine frame, so as to constrain said first rod 12 and second rod 14 in their movement.

Parallelepiped block 50 is constrained to first rod 12 by two first screws 52.

The parallelepiped block 50 can slide inside an elongated seat 54 formed in the second bar 14, adjacent to the second U-shaped body 22, and delimited by two second screws 56.

The parallelepiped block 50 is fixed to the second rod 14 by a small plate 58 which enters the second rod 14 and is fixed to said parallelepiped block 50 by two screws 60.

The square pin 30 acts as a fulcrum for the first lever 12 and the second lever 14 and enables a substantially horizontal translation of the first lever 12 and the second lever 14.

The parallelepiped block 50 cooperates with this movement of the second bar 14 with respect to the first bar 12, since it allows only a relative movement of the two

bars

12, 14 in a rectilinear direction parallel to the greater extension direction of said

bars

12, 14.

The first, second and third U-shaped

bodies

20, 22, 24 receive a kinematic group 32 which, in its articulated movement, moves the first and

second bars

12, 14 in an oscillating and translating movement.

The kinematic group 32 comprises a rotation pin 34 to which a first cylindrical body 36, a cylindrical element 38 and a second cylindrical body 40 are fixed.

The first cylinder 42 is associated with the first cylindrical body 36 and may be disposed in an eccentric position with respect to the axis of rotation of the first cylindrical body 36.

In particular, the eccentricity of the first cylinder 42 can be adjusted by means of the first adjustment screw 41.

The first cylinder 42 is housed in a corresponding cylindrical seat made of a first square block 43, to move vertically in the first U-shaped body 20.

Similarly, the second cylindrical body 40 is associated with a second cylinder 44, which can be arranged in an eccentric position with respect to the axis of rotation of the second cylindrical body 40.

In particular, the eccentricity of the second cylinder 44 can be adjusted by means of a second adjusting screw 45.

The second cylinder 44 is housed in a corresponding cylindrical seat made of a second square block 46, to move vertically in the third U-shaped body 24.

The cylindrical element 38 is also eccentric, since the outer cylindrical surface is not coaxial with the rotation pin 34.

The cylindrical element 38 is housed in a cylindrical seat of a third block 48 designed to move horizontally in the second U-shaped body 22.

With one rotation of the rotation pin 34, the first cylindrical body 36 rotates together with the first eccentric cylinder 42, which moves the first square block 43 accommodating the first cylinder.

The vertical component of motion of the first cylinder 42 causes the first block 43 to translate vertically into the first U-shaped body 20, while the horizontal component of motion of the first cylinder 42 causes the entire first rod 12 to translate horizontally.

Similarly, as the rotation pin 34 rotates, the second cylindrical body 40 also rotates together with the second eccentric cylinder 44, which moves the second square block 46 that houses the second cylinder.

Also in this case, the vertical movement component of the second cylinder 44 causes the second square block 46 to translate vertically inside the third U-shaped body 24, while the horizontal movement component of the second cylinder 44 causes the entire second rod 14 to translate horizontally.

The cylindrical element 38, also eccentric, also moves the third shaped block 48, which moves in the second U-shaped body 22.

In the same way as described above, the horizontal movement component of the cylindrical element 38 causes a horizontal translation of the third square block 48 in the second U-shaped body 22, whereas the vertical movement component of the cylindrical element 38 causes a vertical translation of the whole second rod 14.

The vertical movement of the second rod 14 causes a simultaneous and identical vertical translation of the first rod 12, since the parallelepiped block 50 blocks vertically the two

rods

12, 14 as previously described.

On the other hand, in terms of horizontal translation, the first rod 12 and the second rod 14 remain independent, since the parallelepiped block 50 allows independent horizontal translation.

By varying the eccentricity of the first cylinder 42 and the second cylinder 44 in different ways, acting on the first adjustment screw 41 and the second adjustment screw 45, respectively, the horizontal movement of each of the two rods can be adjusted.

Thus, the set of jaws 16 follows the movement of the end of the first lever 12 and the single jaw 18 follows the movement of the end of the second lever 14.

These movements are both swinging and translation, since the two rods are hinged in a square pivot 30, which, however, acts as a slider in the first seat 26 and in the second seat 28 and allows a horizontal translation of said

rods

12, 14.

On the other hand, the vertical movement of the jaw set 16 and the single jaw 18 is uniform and is accommodated by the fixed eccentricity of the cylindrical member 38.

The fabric feeding device 10 according to the invention thus allows different strokes, in particular in the horizontal direction, of the single gripper jaw 18 acting on the upper fabric sheet with respect to the group of gripper jaws 16 acting on the lower fabric sheet.

Thus, the fabric feeding device 10 ensures an optimal movement of the upper fabric sheet irrespective of the pressure of the presser foot and the different movement speeds of the lower fabric sheet.

In addition, it improves the sewing quality, enabling uniform sewing of the piece of sewn fabric, regardless of the action of the operator on the sewing machine.

Furthermore, variations and modifications are contemplated and are considered to be within the scope of the present invention.

For example, different connection systems between the two rods may be used, allowing independent horizontal translation of the two rods, but not vertical translation.

Claims

1. A fabric feeding device (10) for sewing machines, comprising a first rod (12) at one end of which a first jaw (16) is fixed, a first U-shaped body (20) open downwards being provided on the opposite end of said first rod (12), an elongated first seat (26) being formed in said first rod (12), a square pin (30) being housed in said first seat and being designed to act as a fulcrum of the first rod (12) and as a slider so as to translate in said first seat (26) so that said first rod (12) can move according to a horizontal oscillating and translating movement, said fabric feeding device comprising a rotation pin (34) to which a first cylindrical body (36) is fixed, a first cylinder (42) eccentric with respect to the axis of said rotation pin (34) being associated with said first cylindrical body, said first cylinder (42) being housed in a corresponding cylindrical seat formed in a first square block (43), said first square block being adapted to translate vertically in said first U-shaped body (20), characterized in that said fabric feeding device comprises a second rod (14) at one end of which a second jaw (18) is fixed, at the opposite end of said second rod (14) a second U-shaped body (22) open towards the rear of the second rod (14) and a third U-shaped body (24) open downwards, an elongated second seat (28) being formed in said second rod (14) in which said square pin (30) is received and adapted to act as a fulcrum for the second rod (14) and as a slide to translate in said second seat (28) so that said second rod (14) can move according to a horizontal oscillating and translating movement, a second cylindrical body (40) being comprised and fixed to a rotation pin (34) and a second cylindrical body (44) eccentric with respect to the axis of said rotation pin (34) and with said second cylindrical body (24) -in association, said second cylinder (44) is received in a corresponding cylindrical seat formed in a second square block (46) adapted to translate vertically in a third U-shaped body (24), a cylindrical eccentric element (38) is included and fixed to the rotation pin (34) and is received in a cylindrical seat formed in a third square block (48) adapted to translate horizontally in said second U-shaped body (22).

2. The fabric feeding device (10) according to the preceding claim, wherein a parallelepiped block (50) integral with said first bar (12) is received in and slides in an elongated seat (54) formed in said second bar (14), enabling horizontal translation of said second bar (14) with respect to said first bar (12) and preventing any other relative movement between said first bar (12) and said second bar (14).

3. The fabric feeding device (10) according to the preceding claim, wherein the parallelepiped block (50) is constrained to said second bar (14) by means of small plates (58).

4. The fabric feeding device (10) according to any one of the preceding claims, wherein the position of said first cylinder (42) with respect to said first cylindrical body (36) is adjustable so as to vary the eccentricity of said first cylinder (42) with respect to said rotation pin (34).

5. The fabric feeding device (10) according to the preceding claim, wherein the position of said first cylinder (42) with respect to said first cylindrical body (36) is adjustable by means of a first adjustment screw (41).

6. The fabric feeding device (10) according to any one of the preceding claims, wherein the position of said second cylinder (44) with respect to said second cylindrical body (40) is adjustable so as to vary the eccentricity of said second cylinder (44) with respect to said rotation pin (34).

7. The fabric feeding device (10) according to the preceding claim, wherein the position of said second cylinder (44) with respect to said second cylindrical body (40) is adjustable by means of a second adjustment screw (45).