US3734041A

US3734041A - Sewing machine presser foot

Info

Publication number: US3734041A
Application number: US00117004A
Authority: US
Inventors: R Robert
Original assignee: Mefina SA
Current assignee: Mefina SA
Priority date: 1970-03-06
Filing date: 1971-02-19
Publication date: 1973-05-22
Anticipated expiration: 1990-05-22
Also published as: JPS5136651B1; IE34959B1; SE365005B; ES388940A1; NL7102686A; GB1341919A; AT309189B; CA939976A; DE2108999A1; DK136539B; CH505931A; FR2083929A5; IE34959L; BE763111A

Abstract

The presser foot has a sole hinged on an intermediate support member which is pivoted on a main support member through a deformable parallelogram of links. The main support has a yoke and screw to clamp the presser foot to the presser bar. A paw may be rigidly fixed to the main support member to hold the fabrics to be sewn when the sole is released. The sole can be drawn in the direction of passage of the fabrics when urged towards the feed dog thereby preventing relative slippage of glossy or binding fabrics. A restoring device is coupled to the needle actuating mechanism to bring the sole back into a neutral position when released.

Description

United States atent [1 1 Robert SEWING MACHINE PRESSER FOOT Ramon Casas Robert, Geneva, Switzerland Assignee: Meiina S.A., Fribourg, Switzerland Filed: Feb. 19, 1971 Appl. No.: 117,004

[75] Inventor:

[30] Foreign Application Priority Data Mar. 6, 1970 Switzerland ..3302/70 References Cited UNITED STATES PATENTS 1/1971 Seaman ..112/212 1 May 22,1973

1,474,966 11/1923 Hayes ..112/212 2,742,009 4/1956 Enos ..112/235 Primary Examiner-Patrick D. Lawson AttorneyEmory L. Groff and Emory L. Groff, Jr.

[57] ABSTRACT The presser foot has a sole hinged on an intermediate support member which is pivoted on a main support member through a deformable parallelogram of links. The main support has a yoke and screw to clamp the presser foot to the presser bar. A paw may be rigidly fixed to the main support member to hold the fabrics to be sewn when the sole is released. The sole can be drawn in the direction of passage of the fabrics when urged towards the feed dog thereby preventing relative slippage of glossy or binding fabrics. A restoring device is coupled to the needle actuating mechanism to bring the sole back into a neutral position when released.

Pmmmw w 3,734,041 SHEET 1 OF 2 I INVENTOR Rama/v cA-SAS- ROBERT ATTORNEY PATENTED HAY 2 2 I973 SHEEf 2 [IF 2 1N VENTOR ATTORNEY SEWING MACHINE PRESSER FOOT The present invention relates to a sewing machine presser foot.

The operation of sewing two pieces of fabric to one another by means of a sewing machine can create certain problems, in particular when the sewing of fabrics very slippery with respect to one another is involved, especially those based on synthetic fibers, such as fine machine-knitted or woven materials or other fabrics or, on the other hand, when fabrics which slide with great difficulty are concerned, such as rubberized fabrics, plastics, etc. In fact, it is then observed that only the lower piece of fabric, which is directly in contact with the feed dog, is drawn on uniformly, the upper piece of fabric only following the movement of the lower piece with a delay or with a displacement resulting from the sliding of one piece on the other. In certain industrial sewing machines, the lower feed dog has been completed by a feed dog arranged above the parts to be sewn and of which the movement is synchronized with the lower feed dog. However, such a device complicates the mechanism of the sewing machine and makes it expensive, which is hardly acceptable for a domestic sewing machine, for example.

It is an object of the present invention to enable, by a simple and inexpensive structure, correct feeding of the pieces of fabric, even in the difficult cases of fabrics which are too slippery, or on the other hand, too difficult to slide on one another.

It is another object of the invention to provide an improved presser foot for a sewing machine, which overcomes the above-mentioned drawbacks.

To this end, according to the invention, there is provided a presser foot for a sewing machine comprising a sole for pressing the fabric during its passage, characterized in that the sole is movable in the direction of movement of the fabric, this foot comprising a device for restoring the sole into a neutral position, this device being connected to the needle actuating mechanism.

In order that the invention may be more fully understood, one embodiment of a presser foot according to the invention is described below, purely by way of illustrative but non-limiting example, with reference to the accompanying diagrammatic drawings, in which:

FIG. 1 is a view of said embodiment in side elevation, partly in section, mounted on the presser bar of a sewing machine;

FIG. 2 is a view in front elevation, partly in section, of this presser foot;

FIGS. 3 to 6 are views similar to that of FIG. 1 showing on a reduced scale the various phases of operation of this presser foot; and

FIG. 7 is a plan view of the latter.

With reference to FIGS. 1 and 2, the machine presser foot shown is assumed to be mounted on a sewing machine of which a portion of the head 1 is visible, and also the needle hole plate 2 and the fabric feeder claws or feed dog 3. In this head 1, the needle bar 4 is slidable vertically and bears a needle clamp 5 provided with a neck 6 into which passes a fixing screw 7 for the needle 8.

Parallel to the needle bar 4 in the head 1 is arranged a presser bar 9 subject to the action of a spring (not shown in the drawing) and tending to urge this bar 9 downwardly. A lever mechanism of known construction enables this presser bar 9 to brought into an upper position on preparing the sewing machine. At its lower part, this presser bar 9 has a threaded hold 10 inside of which is screwed a fixing screw 11 for the presser foot proper. This presser foot comprises a clamping member 12 constituting a main support, said clamping member having two spurs 13 in a form of a yoke intended to be applied against the lower part of the presser bar 9. This screw 11 grips by its head the said spurs 13 against the presser bar 9. This main support 12 is extended at its lower part by a fixed paw 14 provided with an opening 15 for the passage of the needle 8 and a slot 15a for the introduction of the thread.

The sole 16 of this presser foot is hinged with respect to the main support 12, this through the interposition of an intermediate support 17. This intermediate support 17 is itself connected to the main support 12 through

transversal links

18 and 19 pivoted to suspension links 20 and 21. This assembly of links 18-21 constitutes a deformable parallelogram comprising a fixed pivoting axle 22 borne by the main support 12, a movable pivoting axle 23, an axle 24 connecting the links 20a and 20b to the transverse link 18 and a pivoting axle 25 connecting the other end of the link 18 to the link 21. A tongs spring 26 is engaged around the pivoting axle 22 and one of its ends 27 is fastened to the axle 23, while its other end 28 is supported against a part of the main support 12 (see FIG 5). This spring 26 therefore tends to make the deformable parallelogram pivot so as to urge the sole 16 lightly against the parts to be

sewn

48, 49. The said sole 16 is hinged to the support 17 by pivoting

axles

29a and 29b.

The transverse link 19 has a lateral extension 30 on one of the edges of which is arranged a cam 31 The link 20a is rigidly fixed to a folded lug 32 provided with an extension in a form of the fork 33, with two teeth, defining between them a notch 34 of V-shape on the opposite edges of which are formed two cam profiles 35 and 36.

The main support 12 bears, in addition, a pivoting axle 37 for a lever 38 of which one arm bears a pivoting axle 39 on which a roller 40 intended to cooperate with the cam 31, is rotatable. This lever 38 also bears a finger comprising an axle 41 hearing a roller 42 capable of cooperating with one or other of the two cam profiles 35 and 36. Another arm 43 of this lever 38 has a slot in the form of a slide 44 engaged around the neck 6 rigidly fixed to the needle clamp 5. This arm 43 of the lever 38 is hence integral in movement, through the hinge-slide 44, with the needle bar 4. The upper thread 45 used for sewing has been shown in the drawing passing through a thread-guide member 46 borne by the needle clamp 5 and engaged in the eye 47 of the needle 8'.

The operation of the sewing machine presser foot described above with respect to the drawings is as follows:

This presser foot is accordingly fixed to the presser bar 9 of an ordinary sewing machine in the same manner as all presser feet of conventional construction, by means of clamping screw 11. On assembling, the slide 44 is engaged on the neck 6 rigidly fixed to the needleclamp 5. FIG. 1 shows the various members of this presser foot when the need 8 is disposed in the vicinity of its highest position with respect to the needle hole plate 2. In this position, the roller 40 acts on the cam 31 and thus pushes back the link 19 in anti-clockwise direction, around the axle 22, which has the effect of pushing the sole 16 downwardly by means of the link 21 and the support 17. The latter is therefore held firmly in contact with he parts to be

sewn

48 and 49 which are flattened against the feed dog 3.

During the downward movement of the needle 8 which the first phase is shown in FIG. 3, the roller 40 follows the cam 31 and ends by losing all action against this cam .31 when it reaches the lower part 50 of the said cam 31. During the stitching phase of the needle 8 in the parts to be

sewn

48, 49, which phase shown in FIG. 4, the dog 3 is withdrawn under the needle-hole plate 2, the roller 40 is without action on the cam 31 and the link 19 respectively, but on the other hand the roller 42 is engaged in the V-shaped notch 35 and comes in the contact with one or other of the cam profiles 35 and 36 to cause centering of the sole 16. In fact, this operation of centering is necessary after each stepwise forward or backward movement of the feed dog 3. The roller 42 therefore acts through the lug 32 on the link 20a ensuring centering of the sole 16 through the interposition of the link 18 and of the support 17. It should be noted that during the phase represented in FIG. 4, the paw 14 supports the parts to be

sewn

48, 49 around the hole for the passage of the needle 8.

On the re-ascending stroke of the needle 8, which stroke is shown in FIG. 5, the lever 38 is driven to more in clockwise direction and as soon as the needle 8 has left the parts to be

sewn

48 and 49, and the feed dog 3 starts to project through the needle-hole plate 2, the roller 40 by cooperating with the cam 31 tilts the link 19 in anticlockwise direction, which forces downwards the link 21, the pivoting axle 25, the intermediate support 17, the

axle

29a, 29b, and thus the presser foot 16 against the feed dog 3. The sole 16 is hence held firmly applied against the parts to be

sewn

48 and 49 which are gripped between this sole l6 and the feed dog 3 preventing any sliding between these two

parts

48 and 49. During this pressing movement of the sole 16 against the feed dog 3, the presser bar 9 is pushed back upwardly against the action of its pressure spring arranged in the head 1 of the sewing machine thus disengaging the paw 14 on the parts to be

sewn

48, 49.

FIG. 6 shows thepositions occupied by the various members of the presser foot, when the feed dog 3 of the sewing machine actuates a recoil movement of the parts to be

sewn

48, 49 with respect to the needle hole plate 2. FIG. 6 shows clearly how the sole 16 is then driven towards the left, with respect to this figure, by the feed dog 3, while the roller 40 acts on the cam 31 to apply said sole 16 against the parts to be sewn. As soon as the needle 8 is re-engaged in the parts to be

sewn

48, 49, the feed dog 3 being withdrawn under the needle-hole plate 2, the sole 16 will again be free of any heavy pressure, apart from that resulting from the spring 26 and the roller 42 will be engaged in the notch 19 to cause re-centering of the sole 16 with respect to the needle 8.

Numerous variations of the presser foot described above could be envisaged. Thus, the device for transmitting movement between the needle actuating mechanism 8 and the deformable parallelogram 18-21, instead of being constituted by the lever 38 driven by the neck 6, could be formed by any other transmission mechanism acting directly, from drive mechanism ar-- ranged in the head I, on the said deformable parallelogram 18-21. In the example described above with regard to the drawings, the link 18 constitutes one and the same part with the intermediate support 17. However, it is clear that the intermediate support 17 could be constituted by a part coupled or rigidly fixed to the link 18 or another part of the deformable parallelogram 18-21, especially the link 21 or the axle 25. All such changes and modifications in the embodiment described above are to be regarded as within the scope of the invention as defined by the appended claims.

I claim:

1. In a sewing machine, a presser foot, a feed dog, a presser bar and a needle-actuating mechanism, said presser foot comprising a sole for pressing fabric during its passage, means coupling said sole to the presser bar so as to be movable in the direction of movement of the fabric, a device for restoring the sole into a neutral position, said restoring device being connected to the needle-actuating mechanism, said coupling means comprising an intermediate support on which the sole is pivoted, a main support to which said intermediate support is pivoted, links arranged as a deformable parallelogram constituting said pivot, wherein said restoring device comprises a motion transmitting device arranged between the needle actuating mechanism and said deformable parallelogram to cause a lowering of the sole against the feed dog during the phase of passage, so that the parts of fabric to be sewn are gripped between the feed dog and the sole and are drawn in translation movement by the feed dog, the sole following said translation movement.

2. A sewing machine according to claim 1, wherein the motion transmitting device comprises a lever pivotally mounted on the main support, a control cam with which one arm of the lever cooperates rigidly fixed to one of the links forming the deformable parallelogram, while the other arm of said lever is integral in movement with the needle bar through a sliding pivot.

3. A sewing machine according to claim 2, including a paw rigidly fixed to the main support and arranged to hold the parts to be sewn when the sole is released.

4. A sewing machine according to claim 2, wherein one of said links bears a centering cam, and a finger on said lever cooperates with said centering cam on each downward stroke of the needle, to center the sole when the latter is released.

5. A sewing machine according to claim 1, including a paw rigidly fixed to the main support and arranged to hold the parts to be sewn when the sole is released.

6. In a sewing machine, a presser foot, a feed dog, a presser bar and a needle-actuating mechanism, said presser foot comprising a sole for pressing fabric during its passage, means coupling said sole to the presser bar so as to be movable in the direction of movement of the fabric, a device for restoring the sole into a neutral position comprising a centering cam, and a lever pivotally mounted on said coupling means and cooperating with said centering cam on each downward stroke of the needle, to center the sole when the latter is released.

7. A sewing machine according to claim 6, wherein the centering cam comprises a double profile forming opposite edges of a V-shaped notch, a finger on said lever cooperating with one or the other of the edges of said notch according to whether the feed dog actuates a forward or backward movement of the parts to be sewn.

8. A sewing machine according to claim 6, wherein the centering cam comprises a double profile forming opposite edges of a V-shaped notch, a finger on said lever cooperating with one or the other of the edges of said notch according to whether the feed dog actuates a forward or backward movement of the parts to be sewn.

9. A sewing machine according to claim 6, including a paw rigidly fixed to the main support and arranged to hold the parts to be sewn when the sole is released.