US3568615A

US3568615A - Method and apparatus for applying fabric lubricant in a sewing machine

Info

Publication number: US3568615A
Application number: US786961A
Authority: US
Inventors: Kenneth W Stretton
Original assignee: WOOD BASTOW AND CO Ltd
Current assignee: WOOD BASTOW AND CO Ltd
Priority date: 1967-12-30
Filing date: 1968-12-26
Publication date: 1971-03-09
Anticipated expiration: 1988-03-09
Also published as: GB1219760A

Abstract

In a sewing machine, a method and an apparatus wherein an atomized stream of a fabric lubricant is continuously supplied under pressure to either a nozzle to spray a jet of lubricant onto the fabric or a separate reservoir. A valve device switches the stream between the nozzle and the reservoir such that a pressurized stream is readily available as a jet at the nozzle when needed.

Description

United States Patent [72] Inventor Kenneth W. Stretton [56] References Cited r England UNITED STATES PATENTS P 853,874 5/1907 l-ladsell 112/43 [22] F1led Dec. 26, 1968 2,316,647 4/1943 112/218 [45] Patented Mar. 9, 1971 2,316,648 4/1943 112/218 [73] Ass1gnee Wood, Bastow & Company Limited 2 442 222 5/1948 112/43 32] Priority Dec. 30 1967 3 G 81min 2,650,557 9/1953 l-lauser 112/218 [3 1 33 A; 3,109,398 11/1963 Abramowicz 112/218 [311 3,185,253 5/1965 Lansky 184/55(A) Primary Examiner-Jordan Franklin Assistant Examiner-George H. Krizmanich 54 METHOD AND APPARATUS FOR APPLYING &

FABRIC LUBRICANT IN A SEWING MACHINE 15 Claims 4 having Figs ABSTRACT: In a sewing machine, a method and an apparatus [52] 0.8. CI 112/218, wherein an atomized stream of a fabric lubricant is continu 112/43 ously supplied under pressure to either a nozzle to spray a jet [51] Int. Cl ..D05b67l00, of lubricant onto the fabric or a separate reservoir. A valve D05b 71/04 device switches the stream between the nozzle and the reser- [50] Field of Search 112/256, voir such that a pressurized stream is readily available as a jet 260, 218, 219, 43; 184/55 (A) at the nozzle when needed.

PATENTEDHAR slam 3.568.615

SHEET 2 UF 4 FIG2.

MMTEQE AND APPARATUS lFGll-l APPLYING FABRMI LUBRLQANT EN A @EWHNG MACE This invention is for improvements in or relating to sewing machines and to methods of using sewing machines. In the manufacture of articles of clothing from fabrics incorporating an elastic thread problems often rise in the sewing together of one or more plies of such fabric. The problem arise due to the fact that when the needle of the sewing machine enters the fabric there is a possibility that the point of said needle will cut into one of the elastic threads forming the fabric. if this happens the elastic thread normally under tension will tend to run back into the fabric, it will probably form a hole in the fabric and in any event will create an unsightly appearance in the fabric and render the article with such a cut thread unacceptahis.

The expression elastic thread as used herein includes both threads made from natural and synthetic rubber and those type of threads now known in the textile trade as elastomeric yarns.

It has also been found that with sewing machines operating at high speeds, i.e. upwards of 3,500 stitches per minute that frictional forces occur as the needle is inserted into and withdrawn from the fabric and as the sewing thread also passes through the fabric to such an extent that heat is generated and it has been found that this heat damages yarns made of synthetic plastics material which are susceptible to damage at elevated temperatures. It has been found that in the sewing of certain elastic fabrics incorporating elastomeric yarns that needles operated at 5,000 stitches per minute generate heat sufficient to melt elastomeric yarns and this also causes holes or other unsightly and unacceptable blemishes to be formed in the fabric. The heat generated at high sewing speeds will damage all types of fabrics incorporating yarns liable to damage at elevated temperatures whether they be rubber covered or elastorneric.

it is an object of the present invention to provide both apparatus and a method to overcome or minimize this problem.

Accordingly the present invention provides firstly apparatus for use with sewing machines comprising a source of fabric lubricant and means for spraying an atomized jet of lubricant on to the fabric or the needle of the sewing machine immedistely prior to the needle of the sewing machine entering said fabric. The present invention also provides a method of sewing fabric particularly but net exclusively that incorporating elastic yarns which comprises spraying an atomized fabric lubricant on to thefabric or to the needle immediately prior to the needle entering said fabric.

The present invention provides apparatus for use with a sewing machine and with a source of compressed air. Air from a compressor is fed firstly to a pressure regulating valve, from thence to an air filter and from thence to a liquid lubricant container. A venturi tube is provided in the liquid lubricant container so that as the air under pressure passes through said venturi tube the liquid in the container is sucked into the stream and an atomized mixture of air and liquid then fed to a transfer valve. In the transfer valve the stream of lubricant and air is normally directed towards an outlet tube where the stream exhausts to atmosphere within a closed container having a port communicating with the atmosphere, the atomized stream of liquid condenses into liquid within the container and the liquid lubricant returns to the lubricant container by gravity or by other means. if however it is desired to provide a source of air and lubricant adjacent to a needle in a sewing machine the transfer valve is operated to direct the stream of air and lubricant to the sewing machine and to divert it from the exhaust tube. lDesirably means for operating the transfer valve include an interconnection with the treadle or stop/start lever or foot operated switch of the sewing machine itself, so the interconnecting mechanism may be arranged so that the transfer valve is opened frictionally in time before the sewing machine motor is operated and similarly the transfer valve is closed frictionally after the sewing machine motor has stopped.

By the present invention a jet of air and an atomized jet of liquid is directed on to the fabric or to the needle of the sewing machine immediately in the front of the sewing machine and thus immediately prior to the needle or needles if a multineedle machine is employed. The spraying of lubricant on to the needle helps to cool the needle and thus to reduce the possibility of damage caused by a hot needle.

in order that the present invention may be more readily understood reference is now made to the accompanying drawings in which:

PKG. l is a side view of apparatus according to the present invention, as attached to the sewing machine and table;

FIG. 2 is a more detailed diagram showing the various components of the present invention;

FIG. 3 is a detailed perspective view of a presser foot and needle of a sewing machine; and

FIG. 4 is a diagrammatic view of the pneumatic circuit for use with the present invention.

In the FIGS. a tableconsists of an upright l supporting a horizontal surface 4 relative to which is supported a sewing machine 2 driven by a motor 6 located beneath the surface 3 through a belt drive 7. The sewing machine has a needle 3 and a presser foot 31. The needle 3 is reciprocal through a needle guide 33. Beneath the surface 4 is a treadle 5 which operates the stop/start mechanism 6a for the motor 6. The treadle 5 also operates an arm 32 hinged at one end to a bracket 29 which depresses a spring loaded plunger 28 housed in an ON/OFF pneumatic valve 13. An inlet to the valve 13 is connected to a duct ll.

Referring briefly to FIGS. 2 and 4 a duct 8 is connected to a source of compressed air. The duct 8 meets in a T union 9 one part of which is connected to the duct 10 and the other branch of which connects via a duct 22 to a transfer block 16 having a hand operated ON/OFF switch to disconnect the flow of air into the block. When the switch is open air may flow through the block to a pressure regulating valve 17 having two outlets, one of which is connected to a pressure gauge 18 and the other to a duct 23 connecting with an air filter 15. Different air pressures are employed according to the nature of the fabric being sewn and the speed of sewing. The outlet from an air filter 15 connects with a liquid lubricant container is having a venturi tube inside so that as the air presses through the venturi lubricant located in the container 14 is sucked into an airstream and the airstream emerges from the outlet of container 14 into the duct 24 containing atomized lubricant. Duct 24 is connected to a transfer valve 19 arranged normally for a direct passage from duct 24 connecting to a duct 21 which connects with a reclaiming bottle 20. Normally the atomized lubricant in the airstream emerges from a tube inside bottle 20 and the atomized liquid collects as liquid in the bottom of said bottle, the air being allowed to exhaust to atmosphere through an appropriate port in the bottle 20. The liquid collected in the bottom of bottle 20 is returned by gravity via a duct 3 to the lubricant container 14. When air is applied to the transfer valve N as for example by operation of the valve 13 duct ll carries compressed air to the transfer valve and switches the connection from inlet duct 2 to outlet duct 25 which carries the stream of air and lubricant to a nozzle 30 (FIG. 3) which can be adjusted to direct a stream of air and lubricant on to the fabric immediately preceding the entry of the needle 3 into said fabric.

Many fabric lubricants have been found to be suitable. Water-based lubricants for yarns and fabrics may be used but it is through preferable to use nonwater-based liquids. The use of water in close proximity to sewing machine parts and components may in some machines give rise to the introduction of rust or tarnishing or alternatively may dissolve some of the conventional lubricant for the machine itself thus reducing the effective working life of the sewing machine. Alternative fabric lubricants are based on vegetable and mineral oils and one particularly satisfactory oil is that known as Risella" oil marketed by Shell Petroleum Limited.

It has been found that for thicker fabrics an increase in the air pressure is desirable in order to ensure greater penetration of the lubricant into and through the yarns forming the fabric. It is thought that the provision of a fabric lubricant serves the purpose of rendering the yarns forming the fabric with a slippery upper surface which tends to deflect a needle as it enters the fabric and thus to reduce substantially the likelihood of the yarns of the fabric being held while the needle pierces said yarns to cut them. The provision of lubricant encourages the needle to slip round and between adjacent yarns forming the fabric rather than cut into said yarns. Furthermore the deep penetration of the lubricant forms a liquid surface on the surface of the yarns of the fabric and this retards the build up of heat due to the friction of the needle and the sewing thread being passed through the fabric and thus reduces the likelihood of thermoplastic yarns reaching a temperature of which they are adversely affected. The air jet itself further serves to dissipate heat in the needle and adjacent parts and thus to keep cooler those parts of the sewing machine in which heat is generated and which in consequence may cause damage to the yarns forming the fabric.

It has been found that with experiments and using the process according to the present invention that substantially higher speeds for the sewing of elastic fabrics is possible. Speeds up to 6,000 stitches per minute have been found possible without any adverse effect on the fabric itself. In general fabrics whether incorporating rubber-covered threads or elastomeric yarns are less liable to suffer damage when sewn according to the process of the present invention.

1 claim:

1. Apparatus for use with a sewing machine comprising, a fabric lubricant container having an inlet and an outlet, com pressed air means for continuously drawing lubricant from said container and delivering atomized lubricant under pressure through said outlet, a first passage means for connecting said outlet to a first nozzle adjacent the sewing machine needle for spraying a jet of lubricant onto the fabric, a reservoir, a second pawage means for connecting said outlet to the reservoir adapted to collect said lubricant in liquid form, and control means connecting said outlet to only one of said passage means at a time, whereby atomized lubricant under pressure is continuously delivered from said container, said atomized lubricant being delivered to either one of said first or second passages in response to the operation of the control means.

2. Apparatus according to claim 1, wherein said compressed air means includes a venturi tube located adjacent to said lubricant container to withdraw lubricant therefrom.

3. Apparatus according to claim 1, including a regulating valve for controlling the pressure of the air supplied to said container.

4. Apparatus according to claim 1, wherein said control means includes a pneumatically operated valve.

5. Apparatus according to claim 4, including an ON/OFF pneumatic valve and a foot treadle, and wherein said pneumatically operated valve is operated by the ON/OFF pneumatic valve which is in turn operated by the foot treadle, said foot treadle connected also to an ON/OFF switch of the sewing machine.

6. Apparatus according to claim 1, including means for returning the lubricant which is collected in the reservoir to the lubricant container.

7. Apparatus according to claim 1, wherein said compressed air means comprises a compressed air line including, in sequence, a source of pressurized air, a regulating valve for controlling the pressure of the air subjected to the container, and a passage directing said regulated compressed air to the said container.

8. Apparatus according to claim 7, wherein said control means comprises a pneumatically operated valve, and wherein said air line includes means for directing air from said source to said pneumatically operated valve to operate the latter.

9. A method of operating a sewing machine having a sewing needle which enters and passes through a fabric, comprising the steps of: feeding fa 11C to the needle of the sewing machine to sew the fabric, continuously supplying a stream of atomized lubricant under pressure through a passageway from a lubricant container to a reservoir, and diverting said stream from the container at selected times to pass through a nozzle adjacent the sewing machine needle to spray a jet of lubricant onto said fabric.

10. The method according to claim 9, wherein the step of diverting is performed to spray the atomized jet of lubricant onto the fabric immediately before the needle of the sewing machine enters the fabric.

11. The method according to claim 9, wherein the step of continuously supplying a stream includes passing compressed air through a lubricant container to form a stream of air containing atomized lubricant and feeding said stream to a valve having two outlets, one of which is connected to a nozzle adjacent the sewing machine needle and the other of which is normally open and is connected to a reservoir and allows the stream to normally pass to the reservoir.

12. A method according to claim 9, including normally returning the lubricant from said reservoir to said lubricant container.

13. The method according to claim 9, including operating a foot treadle of the sewing machine for determining whether the atomized fabric lubricant flows to the reservoir or directly to the nozzle.

14. The method according to claim 9, in which the lubricant is a nonwater-based lubricant.

15. The method according to claim 9, wherein the fabric includes elastic yarns, and wherein the lubricant is supplied in an amount sufiicient to prevent overheating of the needle and also to reduce the tendency of the needle to hold and pierce the elastic yarns.

Claims

1. Apparatus for use with a sewing machine comprising, a fabric lubricant container having an inlet and an outlet, compressed air means for continuously drawing lubricant from said container and delivering atomized lubricant under pressure through said outlet, a first passage means for connecting said outlet to a first nozzle adjacent the sewing machine needle for spraying a jet of lubricant onto the fabric, a reservoir, a second passage means for connecting said outlet to the reservoir adapted to collect said lubricant in liquid form, and control means connecting said outlet to only one of said passage means at a time, whereby atomized lubricant under pressure is continuously delivered from said container, said atomized lubricant being delivered to either one of said first or sEcond passages in response to the operation of the control means.

9. A method of operating a sewing machine having a sewing needle which enters and passes through a fabric, comprising the steps of: feeding fabric to the needle of the sewing machine to sew the fabric, continuously supplying a stream of atomized lubricant under pressure through a passageway from a lubricant container to a reservoir, and diverting said stream from the container at selected times to pass through a nozzle adjacent the sewing machine needle to spray a jet of lubricant onto said fabric.

15. The method according to claim 9, wherein the fabric includes elastic yarns, and wherein the lubricant is supplied in an amount sufficient to prevent overheating of the needle and also to reduce the tendency of the needle to hold and pierce the elastic yarns.