GB2256653A - Button sewing machine - Google Patents

Abstract

On the bed of a button sewing machine a mounting plate (10) is pivotable about an axis (12) which permits simple and rapid changing of different button arms (18, 19, 20) mounted on the plate. Detents (13) secure the plate in its selected position. Fig 13 shows a so called slack finger device (48) for forming long thread shanks attaching buttons, the device (48) being mounted by a block (46) on a pivotal arm (40) which is provided with a quick release lever for displacing the device (48) clear of the thread when the button has been sewn on. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO SEWING MACHINES This invention relates to sewing machines and more specifically to sewing machines which are intended to sew a button onto a piece of clothing or fabric. An example of such a sewing machine is the type used in sewing buttons onto suits or jackets.

Sewing machines used to sew buttons onto clothing, such as suits and jackets, are often required to sew different types of buttons, sometimes in different formats, onto the suit or jacket. For example some suit jackets have a small button inside the jacket for purposes of anchoring a larger button on the outside.

These smaller buttons are known as backing buttons. In another type of jacket a retailer may require the button to lie flat against the jacket without any slack in the cotton attaching the button to the jacket. On the other hand a different retailer may require a long length of cotton, or shank, and a loose lying button.

Different buttons are supported by different types of support arms which may be behind the material of the jacket, or may lie adjacent a pinched portion of material. These so called button backing arms serve to support the button so as to facilitate sewing.

A problem in the past has been that up to three different sewing machines have been required in order to sew the different buttons, perhaps in different formats, onto one type of jacket. This has been expensive, both from the point of view of initial machine costs and also maintenance. One way to alleviate the problem has been to employ an engineer to change the so-called button arms, so that one machine may be modified so as to sew different buttons. However, this has lead to a down-time in the machine, typically of half-an-hour, during which the engineer has had to remove one backing arm fit another button arm and set the newly fitted button arm so that it is truly aligned and permits efficient and effective sewing.

According to a first aspect of the present invention there is provided a mounting plate for supporting a button arm, the mounting plate being rotatable about an axis to at least two different positions and having means for locking the mounting plate into one of the positions.

In a preferred embodiment three studs are provided which are arranged to slot into a hole. In an alternative embodiment a locking nut may "sit" in an arcuate groove, the locking nut is arranged to lock onto a spindle so as to urge the mounting plate against a machine bed.

Preferably three different button arms are provided together with three locking means each locking means being arranged to lock in a position in which only one arm may be used to support a button.

Because the mounting plate is able to rotate about a shaft and it is capable of being locked into a position; for example by way of a locating stud in a hole or slit in the mounting plate, an operator is able to change from one button arm to another, simply by disengaging the mounting plate from a position, rotating it so that the desired arm is in position and then engaging a stud into the correct hole.

Preferably a resiliently deformable means is present so as to urge the backing plate against a sewing machine bed. This resiliently deformable means advantageously is a spring around a pivot pin and means may be provided to alter the tension in the spring so as to alter the intensity with which the mounting plate presses against the machine bed.

Studs are preferably provided on the machine bed and oval shaped slots are provided in the mounting plate.

However, it would be equally possible to have studs or projections on the mounting plate and sympathetic indentations or grooves in the machine bed. The slots in the mounting plate are oval shaped so that the studs assist in the alignment of the button arms.

Holes may be formed in the rotating mounting plate so as to permit different types of button arms to be connected to it or to be replaced if they become damaged or worn. Preferably the button arms are connected by way of two allen screws so as to prevent any lateral movement of the button arms with respect to the mounting plate.

A particularly preferred embodiment permits the machine operator to lever the button arm upwards rotate the mounting plate about its pivot pin, as to move a different button arm into position, and then release the lever enabling the button arm to rest around the stud, thereby locating it exactly for the different button format to be sewed. This greatly facilitates the speed of changing tools and removes the aforementioned down-time, as the tool may now be changed in a matter of seconds.

Preferably the button arms are formed from sprung steel and are arranged on the mounting plate so that they lie flat against the machine bed. This is important as with some types of button or sewing formats, the button is required to sit tightly against the fabric onto which it is to be sewn.

In a different sewing format to the one just mentioned, the button is desired to have a long shank attaching it to the jacket, or needs to hang loose from the fabric once sewn onto it. In practise this is achieved by inserting a so-called slack finger device on to the button so that the device lies between each of the two sets of two holes in the button. Sewing is performed around the slack finger device and because the slack finger has a thickness of two or three millimetres additional thread is needed to go around the slack finger. When the slack finger is removed this additional thread is taken up and cotton is wound around the shank between the back of the button and the surface of the fabric so as to form a loose lying button.

A problem in the past has been that the slack finger has sometimes caught on the button, once it has been sewn onto the fabric, thereby making it difficult for the operator to remove the garment without damaging the garment or the thread.

According to a second aspect of the present invention a support device for a slack finger is provided wherein the support device urges the slack finger into a space between button holes during a sewing cycle and automatically withdraws the slack finger from the space between the button holes at the end of a cycle.

Withdraw of the slack finger may be achieved either by using a slack finger formed from a resiliently deformable material; tensioning this during the sewing cycle and removing the tension at the end of a cycle; or it may be achieved by mounting the slack finger on a movable carriage, moving the carriage prior to the sewing cycle so that the slack finger is on the button during the sewing cycle and removing the carriage at the end of a sewing cycle so as to withdraw the slack finger.

Preferably the slack finger is formed from a piano wire and is mounted on a mounting block. The mounting block is in turn mounted on a swing arm which is rotatable about a hole which has been formed at a distance from the slack finger device such that a slight rotational swing in the arm is sufficient to remove the finger from within the sewn portion of the button.

An embodiment of each of the above aspects of the present invention will now be described, by way of examples only,and with reference to the figures in which: Figure 1A shows a plan view of a mounting plate; Figure 1B is a side elevational view of the mounting plate of Figure lA; Figure 2 shows a plan view of a mounting plate with three button arms connected to it; Figure 3 shows a sectional view along the line Y-Y of Figure 2; Figure 4A is a plan view of a button arm; Figure 4B is a side elevational view of the button arm of Figure 4A; Figure 5A is a plan view of a jigger button arm; Figure 5B is a side elevational view of the button arm of Figure 5A; Figure 6A is a plan view of a angled button arm; Figure 6B is a side elevational view of the button arm of Figure 6A; Figure 6C is an end elevational view of the button arm of Figure 6A;; Figure 7 is a side elevational view of a pivot pin; Figure 8A is an above plan view of a swing out arm; Figure 8B is a side elevational view of the swing out arm of Figure 8A; Figure 8C is an underplan view of the swing out arm of Figure 8A; Figure 9A is a plan view of a mounting block for a loose shank finger device; Figure 9B is a side elevational view of the mounting block of Figure 9A; Figure 9C is a detailed view of one portion of the mounting block shown in Figure 9B; Figure 10A is a plan view of a mounting block for a spacing wire; Figure 10B is a side elevational view of the block of Figure 10A; Figure 10C is an underplan view of the mounting block of Figure 10A; Figure 11 is a side elevational view of spacing wire; Figure 12A is a side elevation view of a quick release lever;; Figure 12B shows the actual size of one embodiment of the lever; and Figure 13 is a diagramatical perspective view of the assembled swing out arm with the mounting blocks in place.

A first aspect of the invention will be described with reference to Figures 1 to 7 inclusive. The mounting plate 10 is formed from a stainless steel sheet of approximately 2mm thickness and has rounded deburred corners llA, 11B, llC and llD. A hole 12 is drilled or punched into the mounting plate 10. Three further oval shaped locating holes 13A, 13B and 13C are punched on an arc of a circle whose centre is at the centre of hole 12. Groups of holes 14A and 14B, 15A and 15B, 16A and 163, and 17A and 17B are drilled around the periphery of the mounting plate 10 and are intended to support button arms as shown in Figure 2.

The different button arms shown in Figure 2 are a pinch button arm guide 18, a jigger button arm 19 and a backing button arm 20.

The support holes 14A and 14B are redundant because the pinch button arm 18 is mounted onto the mounting plate 10 by allen bolts 21A and 21B through holes 15A and 15B respectively. Allen bolts 22A and 22B mount the jigger button arm 19 onto the mounting plate 10 through holes 16A and 16B respectively. Allen bolts 23A and 23B mount the backing button arm 20 onto the mounting plate 10 through holes 17A and 17B respectively. Figure 2 also shows a sectional view along the line X-X of the pinch button arm guide 18 and shows how the arm guide 18 is arcuate and is arranged to flex. This arm guide 18 is shown in detail in Figure 6C.Each of the button arms 18, 19 and 20 has a ribbed dog-leg portion 18A, 19A and 20A respectively, for imparting a springiness into each of the arms so that they are urged against a machine bed 24 as shown in Figure 3.

A pivot pin 25 is threaded so as to pass through the hole 12 and is surrounded by a spring 26 shown ind etail in Figure 7. The spring 26 impartsa comprssionforce onto the mounting plate 10 and urges it against the machine bed 24. Locating stud 26 passes through hole 13C. so as to prevent the mounting plate from rotating once "set".

Figure 4 shows the backing button arm 20 and oval holes 27A and 27B. Allen bolts 23A and 23B pass through these holes respectively and bolt the button arm 20 to the mounting plate. The holes are oval shaped so as to permit a slight axial displacement of the button arm backwards and forwards. This enables precise alignment of the button arm. Figure 4B shows how a dog-leg is formed in the button arms so as to enable material to pass between the region supporting the button (not shown) and the machine bed 24. A thick washer 28 is soldered or bonded centrally over hole 29 in the button arm 20 and this helps to support a button. Figure 5A and B show the jigger button arm 19 with oval holes 30 and Figure 6A and B show the pinch button arm guide 18 with oval holes 31A and 31B. Figure 6C shows a sprung portion 32 of the button arm 18.

All the button arms 18, 19 and 20 are formed from spring steel which has been deburred and polished so as to avoid any material catching on respective button arms and tearing. Figure 7 shows the pivot pin 25 in detail and how this acts as a tension control knob. It will be appreciated that simply by lifting an edge of the respective button arm and rotating the mounting plate 10 clockwise or anti-clockwise a different button arm may be engaged as described above.

A second aspect of the invention will now be described with reference to Figures 8 to 12 inclusive.

A swing out arm 40 is shown generally in Figures 8A, 8B and 8C as having a radiussed distal end 41 with a slot 42 at its other end. A tapped hole 43 is made on the centre line of the swing out arm 40 at approximately 1/3rd of the length along from the radiused distal end 41. Figures 9A, B and C show a swing out arm mounting block 44 which is attached to the swing out arm 40 by way of a threaded bolt (not shown) passing through the slot 42 of the swing out arm 40 and through the tapped hole 45.

Figures 10A, 10B and 10C show a mounting block 46 which is a slide fitting device arranged to sit on and around the swing out arm 40. A drilled and tapped hole 47 is provided in the block through which a screw or bolt (not shown) passes so as to connect the block 46 to the swing out arm 40.

Figure 11 shows a spacing wire 48 and Figures 12A and 12B shows a quick release lever 49.

The aforementioned components shown in Figures 8 to 12 inclusive are shown in the assembled form in Figure 13.

A needle 50 is supported by an arm 51 of a sewing machine 52. The machine bed 24 is semi-cylindrical in shape and is so arranged for receiving articles such as cuffs and sleeves. An existing machine button clamp arm 53 is shown which supports the swing out arm 40 around a pivot 54. The mounting block 46 is connected to the swing out arm 40 by a screw 42A passing through the slot 42. The spacing wire 48 is fitted into the block 46 and is held in place by two grub screws (not shown) which pass through holes 60 and 61 in block 46. Clamp 62 in use supports one of the button arms as shown in Figures 4, 5 and 6. Block 44 is held onto the arm 40 by a pivot 64 and spring 65 arrangement. These ensure that the arm 40 is urged against the existing button clamp arm 53 with sufficient pressure.

The quick release lever 49 is arranged to move the arm 40 and thereby disengage the spacing wire 48 from within the region of cotton once the button has been sewn. This permits the button to be removed easily once sewing is complete. Because of this type of thread wiper trimming system, together with the changeable button arms, all types of button feature combinations can be sewn reliably giving a securely attached button with traditional lockstitch security and durability.

In addition to this, the device is easily fitted to existing machines and new button arms, or replacement button arms, are easily and quickly fitted onto the mounting plate.

The quick release lever 49 is fitted to an existing thread wiper mechanism on a standard button 438 button sewer using an existing screw and washer (not shown). The mechanism is ideal in terms of its movements for the lever 49 to push the slack finger 48 approximately 4mm to the left, thus releasing the thread for easy withdrawal of the sewn on button.

It will be appreciated that the above embodiments are by way of example only and that variation to them may be made, without departing from the scope of the invention.

Claims (17)

1. A mounting plate for supporting a button arm, the mounting plate being rotatable about an axis, to one of at least two different positions, and means for locking the mounting plate, into one of the aforementioned positions.

2. A mounting plate according to claim 1 wherein the locking means comprises a plurality of studs arranged to slot into a hole.

3. A mounting plate according to claim 2 wherein the studs are mounted on the button arm.

4. A mounting plate according to claim 2 wherein holes are defined by the button arm.

5. A mounting plate accordign to claim 3 or 4 wherein the studs are oval shaped.

6. A mounting plate according to any of claims 2 to 5 wherein three studs are provided.

7. A mounting plate according to claim 1 wherein the locking means comprises an arcuate groove arranged to move about a spindle and a nut which may be tightened onto the spindle so as to lock the mounting plate into at least one position.

8. A mounting plate according to any preceding claim wherein three different button arms are supported by the mounting plate.

9. A mounting plate according to any preceding claim wherein a resiliently deformable means is arranged to urge a backing plate against a sewing machine bed.

10. A mounting plate acording to any preceding claim wherein the button arm is formed from sprung steel.

11. A support device for a slack finger wherein the support device urges the slack finger into a space between button holes during a sewing cycle and automatically withdraws the slack finger from the space between the button holes at the end of a cycle.

12. A support device for a slack finger according to claim 11 wherein the slack finger is mounted on a movable carriage which is arranged to move prior to a sewing cycle such that the slack finger is positioned adjacent a button during this sewing cycle and such that removal of the carriage at the end of the cycle withdraws the slack finger.

13. A slack finger device according to claim 11 wherein a support device comprises a resiliently deformable material arranged to tension during a sewing cycle such that removal of applied force at the end of a sewing cycle withdraws the slack finger from a position adjacent the button.

14. A slack finger device according to either claim 11 or 12 wherein the slack finger device is formed from piano wire mounted on a mounting block.

15. A slack finger device according to claim 13 wherein the mounting block is mounted on a swing arm, which swing arm is rotatable about a hole formed at a distance from the slack finger.

16. A mounting plate substantially as herein described with reference to the figures.

17. A slack finger device substantially as herein described with reference to the figures.