US3792674A

US3792674A - Sewing machine

Info

Publication number: US3792674A
Application number: US00184565A
Authority: US
Inventors: Robert R Casas
Original assignee: Mefina SA
Current assignee: Mefina SA
Priority date: 1969-11-04
Filing date: 1971-09-28
Publication date: 1974-02-19
Anticipated expiration: 1991-02-19

Abstract

A sewing machine wherein the upper thread spool is held fast on its spindle within the housing provided for it while the thread is wound off the spool in a direction extending substantially in alignment with the spool axis. The cover of the housing may be shifted outwardly together with the spindle which is secured to it to allow removing and replacing the spool. A cap-shaped member fitted loosely over the spool includes a broad flange guiding the thread as it passes off the spool while means are provided to lock the cover in its closed position and to lift the cap-shaped member off the spindle before releasing the cover.

Description

United States Patent 1191 1111 3,792,674 Casas-Robert 1 Feb. 19, 1974 1 1 SEWINGMACHINE 2,609,772 9 1952 Casas-Robert 112 254 75 l t R C -R b t G I 1 men or 3323 23 0 er eneva Primary Examiner-H. Hampton Hunter Attorney, Agent, or FirmEmory L. Groff; Emory L. [73] Assignee: Mefina S.A., Fribourg, Switzerland G ff, Jr

[22] Filed: Sept. 28, 1971 21 A l N 184565 [57] ABSTRACT 1 PP- 1 A sewing machine wherein the upper thread spool is Related US. Application Data held fast on its spindle within the housing provided for [62] Division of Ser. No. 879,418, Nov. 4, 1969, Pat. No. it While the thread is Wound Off the 511001 in a direc- 3,645,220. tion extending substantially in alignment with the spool axis. The cover of the housing may be shifted [52] US. Cl. 112/254 outwardly together with the spindle which is secured [51] Int. Cl D05b 47/02 to it to allow removing and replacing the spool. A cap- [58] Field Of Search... 112/218 R, 2l8 A, 254, 255, Shaped member fitted loosely over the spool includes 112/59, 97; 226/195; 242/147, 154 a broad flange guiding the thread as it passes off the spool while means are provided to lock the cover in its [56] References Cited closed position and to lift the cap-shaped member off UNITED STATES PATENTS the spindle before releasing the cover.

1,518,494 12/1924 Elcock 112/254 3 Claims, 6 Drawing lFigures PATENTEI] FEB I 91974

sum

1 or 2 FIG.3

I r i .1

PAIENIEB B 3,792,874

SHEET 2 [IF 2 SEWING MACHINE This application is a division of application Ser. No. 879,418, filed Nov. 24, 1969, now U.S. Pat. No. 3,645,220, dated Feb. 29, 1972.

The present invention has for its object a sewing machine the upper part of the frame of which is provided with a housing in which is located a spindle adapted to carry the upper thread spool. v

A number of sewing machines are already known, wherein the upper thread spool is concealed within a housing of the frame. However, in such known machines, the spool is free within its housing and the traction exerted intermittently on the thread by the threaddrawing means incorporated with the sewing machine produces an uneven unwinding of the spool. Now, the machine according to the present invention eliminates said drawbacks and its novelty consists in that it in cludes means for restraining the rotation of the spool while guiding elements provide for the unwinding of the thread in a general direction extending substantially coaxially with the spool.

The accompanying drawings illustrate diagrammatically and by way of example a preferred embodiment of a sewing machine according to the invention. In said drawings:

FIG. 1 is an elevational, partly cross-sectional view of the upper part of the frame of the sewing machine forming the head thereof.

FIG. 2 is a cross-section through line IIII of FIG. 1.

FIG. 3 is a top plan view of the head of the sewing machine. FIG. 4 is a cross-section through line IV-IV of FIG. 1, showing the arrangement of the spoolcarrying spindle in its operative condition.

FIG. 5 is a view of the spool-carrying spindle in the position where the spool is released with reference to the said spindle.

FIG. 6 is a fragmentary top plan view of the head of the machine.

The sewing machine illustrated includes a frame 1 enclosing all of the mechanism controlling the needle bar 2 which moves in a vertical reciprocatory manner within the head of the sewing machine. Said head also carries the presser foot 3 adapted to hold the fabric to be sewn over the mechanism conveying it and which is not illustrated.

The mechanism driving the needle bar 2 also drives the thread drawing means which, in the example illustrated, includes an oscillating lever which is not shown in the drawing since it is concealed by a protective cover 4 provided with a slot 5 (FIG. 4) through which the upper thread 6 passes. Said upper thread 6 is fed by a spool 7 located in a housing 8 formed for this purpose within the head of the sewing machine. In practice and as illustrated in FIGS. 1 and 5, the frame is provided with a recess forming said housing 8, which recess is closed by the cover 9 pivotally secured to a spindle 10 I and 17 are adapted to lock the spool 7 when required with reference to its carrier spindle 12. As a matter of fact, said steel wires 16 and 17 extend when inoperative outside the spool-carrying spindle 12. When a spool 7 has been threaded over said spindle, the steel wires 16 and 17 are urged against the outer periphery of the spindle and exert a frictional stress within the hub of the spool 7 whereby they prevent the latter from rotating round its spindle.

As illustrated more particularly :in FIGS. 1 and 4, the spool-carrying spindle 12 extends along a substantially vertical line. In order to allow the thread 6 to be unwound upwardly, that is in a general direction which is substantially coaxial with the axis of the spindle, elements are provided for guiding the thread, one of said guiding elements comprising a revolvable member 18 in the shape of a cap which revolves around the spoolcarrying spindle. The outer circular edge 19 of said cap 18 has a diameter larger than that of the flange 20 of any spool 7 which may be used with the machine whereby the thread 6 may unwind without contracting at any time the corresponding flange 20 of the spool 7, which flange may even be broken or chipped in certain cases.

The upper part of the frame 1 of the sewing machine is provided with a slot 21 (FIG. 3) through which the thread 6 is adapted to pass into the tension-adjusting means 23. In fact, the tension-adjusting means 23 is fitted on the upper plate 22 closing the frame 1, said means including two plates 24 fitted round a spindle 25, a spring 26 being adapted to urge said plates against each other. A knurled wheel 27 provides for the adjustment of the tensioning of the spring 26 and consequently of the force urging said plate 24 against each other. The tension-adjusting means need not be described with any further detail since it is the subject of US. Pat. No. 3,557,731, filed by the same applicant. When the thread 6 has passed beyond the gap between the plates 24, it engages a guiding element 28 formed by a trough and is directed downwardly so as to partly surround a thread guide 29 and to engage a compensating spring 30. It then moves over the thread-drawing means concealed by the cover 4 and beyond the latter it enters the thread guide 31 from which it is directed towards the needle-clamping means and the eye of the needle, which latter are not illustrated.

The above-described sewing machine may operate perfectly with only the elements disclosed with reference to the accompanying drawings.

However, in order to further the operation of such a sewing machine and primarily to facilitate the insertion and removal of the spool with reference to its carrier spindle 12, said machine advantageously includes means for raising the cap 18 so as to allow it to be re moved from the spindle 12 before the latter is rocked outwardly outside its housing 8. Said raising means includes a support 32 slidingly engaging a spindle 33 extending vertically the housing 8. Said spindle 33 is thus substantially parallel with the axis of the spool-carrying spindle 12 when in its operative position. The support 32 slides over its spindle 33 as provided by its terminal folded extensions 34. The remainder of said support 32 is in the shape of a strap. In other words it includes two flanges 35 lying to either side of the spool-carrying spindle 13 when in its operative position, said flanges extending in proximity with the walls of the housing 8. One of the flanges 35 is provided with an extension 36 projecting outside the housing 8. Said extension 36 forms at its end 37 a control member through which it is possible to operate the support 32 from the outside of the sewing machine when the cover 9 has been closed over the housing 8. It should be noted that said control member 37 serves a further function in connection with said sewing machine.

As a matter of fact, since the extension 36 of the arm 35 extends beyond the outside of the frame 1 of the machine, said control member 37 may also serve as a bolt holding the cover 9 in its closed position over the housing 8. As illustrated in FIGS. 3, 4 and 6, the cover 9 is held closed over the housing by member 37 engaging the outer surfact of said cover 9. The latter can therefore be opened only after raising of the support 32, which is accomplished by a shifting of the control member 37. During said raising movement, the support 32 urged the cap-shaped member 18 upwardly and the latter is held in its raised position together with its support 32 by a locking mechanism when the spool-carrying spindle is in its collapsed position. Said locking mechanism includes a bolt 38 adapted to slide transversely across the upper part of the frame 1 under the action of a spring 39 urging said bolt 38 outwardly of the frame 1. The bolt 38 is normally held in its inoperative position within the frame 1 by the edge 40 of the cover 9 which engages it when the latter is in its closed position as illustrated in FIG. 4. As soon as the support 32 has been shifted upwardly through operation of the control member 37 and has released the cover 9 after it has risen above the upper edge 40 of the latter, the bolt 38 is urged outwardly and thus moves the cover 9 into its open position so as to engage the underside of the control member 37 and hold the latter in the position illustrated in FIG. 5. A plate 41 extending horizontally across the upper part of the frame 1 is provided with a central opening 42 adapted to guide the capshaped member 18 and to ensure thus its centering with reference to the operative location of the spoolcarrying spindle 12, even when the latter has been shifted away from said spindle 12.

It will be readily understood upon inspection of the drawings and particularly FIGS. 4 and that, at the moment of the return of the cover 9 into its closed position over the housing 8, whereby it passes from the position illustrated in FIG. 5 to that illustrated in FIG. 4, the upper edge 40 of said cover 9 urges the bolt 38 back inside the frame 1 which allows the support 32 and capshaped member 18 to drop under the action of gravity over the spool-carrying spindle 12 in contacting relationship with the upper flange of the spool 7. It should be noted that such a sewing machine allows the use both of flanged spools 20 and bobbins such as those illustrated in FIGS. 4 and 5 which include no transverse flanges. In the latter case, the annular flange 19 of the cap 18 forms an advantageous substitute for the flange 20 of the spool and this is all the more true since the cap is preferably made of a material which facilitates the sliding of the thread over it, which is not always the case for the actual spool flange 20.

In order to further the winding of a thread around the cop 53 in the sewing machine described hereinabove, which cop is adapted to be rotatably driven by the winding spindle 54 projecting above the upper surface 22 of the frame 1, said upper surface carries a thread guide 43 consisting of a blade projecting above the frame I. Said thread guide 43 restricts the path followed by the thread so that it will remain constantly located in the medial plane of the cop 53. As illustrated in FIG. 1, said thread guide 43 forms the raised end of a metal blade 44 folded in U-shape and carried inside the frame 1. A screw 45 engaging a transverse opening 46 in the upper surface 22 of the frame 1 and passing freely through one of the arms of the U-shaped blade 44 is screwed into the opposite arm of the latter. The raised end 47 of the blade forming the thread guide passes through a slot 48 in the frame 1. It will be readily understood from inspection of the drawings that tightening or loosening of the screw 45 adjusts the spacing between the two arms of the U-shaped blade 44 and thus produces a more or less considerable projection of the raised end 47 above the surface 22 of the frame 1.

When a cop 53 is to be placed over its winding spindle 54, the thread 6 passing off the spool 7 and out of the frame 1 through the slot 21 engages the gap between the plates 24 of the tension-adjusting means which exerts a preliminary tensioning stress on said thread. The latter then engages the thread guide 43 before it is wound around the cop 53. Said special structure of the sewing machine thus allows the cop 53 to be wound while an adjustable tensioning is exerted by means of the conventional tension-adjusting means on said thread as it leaves the spool 7 towards the cop 53, which is not generally the case in conventionally constructed sewing machines. The tensioning exerted by the thread 6 during the winding operation thus ensures a more uniform distribution of the thread with reference to the cop carrying it.

It should be noted that the sewing machine described hereinabove may be provided above the upper surface 22 of the frame 1 with a second spool-carrying spindle 55 which permits making two-thread stitchings by such a sewing machine. In practice, a second thread spool 56 may be fitted over said spool-carrying spindle 55 and said spool 56 supplies a second thread 57 extending over the thread guide 43 and engaging the cap between the plates 24 so as to be fed by the guide element 28 towards the corresponding needle. The thread 57 then passes between the plates 24 in a direction opposed to that followed by the thread 6 passing off the spool 7. The tension-adjusting means provided for the threads would then exert an action simultaneously on both

threads

6 and 57 without any difficulty and without any further plate being required, since the two threads pass through the tension-adjusting means in opposite directions while the input and output provided for the two threads in said adjusting means are not in registry. In order to facilitate the passage of both threads between the plates 24, their central portion is concave as illustrated in FIG. 4. Of course, it would also be possible to provide the tension-adjusting means with three superposed plates so as to form different passages for the

threads

6 and 57.

The sewing machine described may obviously permit a winding of the cop not only by means of the thread 6 supplied by the spool 7, but also by means of the thread 57 supplied by the spool 56. ,In such a case, the thread 57 would engage the gap between the plates 24 and then return along the path 57a towards the cop 53 carried by its spindle 54. In such a case the winding of the cop would also be executed with the possibility of adjusting the tensioning of the wound thread.

The head of the sewing machine also includes, as illustrated in FIGS. 2 and 4, a housing 49 enclosing a lamp 54 adapted to illuminate the fabric which is being sewn by the sewing machine. As in the case of conventional sewing machines, the lever 51 which controls the operation of the presser'foot 3 may also act by means of a connecting rod 52 on the tension-adjusting means formed by the plates 24 so as to release said plates each time the presser foot is raised off the fabric.

Preferably the cover 9 is made of a translucent or transparent material which allows the amount of sewing thread carried by the machine to be ascertained Numerous modifications of the sewing machine described and illustrated may be made within the scope of the present invention as defined by the accompanying claims. Thus, instead of providing a spool-carrying spindle l2 rocking in unison with the cover 9, said spindle together with the cover 9 may pivot round a vertical axis so as to allow the spool-carrying spindle to be shifted out of the housing 8. According to a further embodiment, said spool-carrying spindle 12 could also be locatedhorizontally provided the housing 8 is given a shape which allows the spool to be introduced horizontally into the head of the sewing machine. As to the means locking the spool 7 over its spindle 12, instead of resorting to steel wires, such means may comprise a catch fitted inside the spool-carrying spindle 12 or any other clamping means, the clamping being performed automatically as soon as the spool has been fitted over its spindle 12. Also the clamping may be obtained by means of a special arrangement such, for instance, as an eccentric system controlled by means carried at the free end of the spindle 12. A further modification may consist also in clamping or retaining means provided for the spool 7 which, instead of acting by means of the spool-carrying spindle 12, may act directly on the outer periphery of the spool.

I claim:

1. In a sewing machine including a body provided trolling the needle, the combination of a spindle located inside the housing in its operative position, an upper thread spool fitted over the spindle, threadguiding elements over which the thread is fed off the spool to the needle, said thread extending initially in a general direction substantially coaxial with the axis of the spindle, means locking the spool on the spindle during unwinding of the thread from the spool to the me dle, said body having a slot in the upper portion thereof, means on the upper portion of said body for adjusting the tension of the thread as it passes off said spool through said slot, through said adjusting means and over said thread-guide elements towards said needle.

2. A sewing machine as claimed. in claim 1, wherein one of said thread-guiding elements comprises a blade projecting above the upper surface of said body to be engaged by the thread wound off said spool through said slot to the needle.

3. A sewing machine as claimed in claim ll, wherein one of said thread-guiding elements comprises a substantially U-shaped blade mounted inside said body, one arm of said blade provided with an extension projecting beyond the top surface of said body and en gaged by the thread wound off said spool through said slot to the needle, means for adjusting the distance said extension projects beyond the surface of said body, said means including a screw threadedly engaging said arm provided with the extension to selectively adjust the height thereof.

Claims

1. In a sewing machine including a body provided with a housing, a needle, means feeding a thread to the needle and a mechanism carried by the body and controlling the needle, the combination of a spindle located inside the housing in its operative position, an upper thread spool fitted over the spindle, threadguiding elements over which the thread is fed off the spool to the needle, said thread extending initially in a general direction substantially coaxial with the axis of the spindle, means locking the spool on the spindle during unwinding of the thread from the spool to the needle, said body having a slot in the upper portion thereof, means on the upper portion of said body for adjusting the tension of the thread as it passes off said spool through said slot, through said adjusting means and over said thread-guide elements towards said needle.

2. A sewing machine as claimed in claim 1, wherein one of said thread-guiding elements comprises a blade projecting above the upper surface of said body to be engaged by the thread wound off said spool through said slot to the needle.

3. A sewing machine as claimed in claim 1, wherein one of said thread-guiding elements comprises a substantially U-shaped blade mounted inside said body, one arm of said blade provided with an extension projecting beyond the top surface of said body and engaged by the thread wound off said spool through said slot to the needle, means for adjusting the distance said extension projects beyond the surface of said body, said means including a screw threadedly engaging said arm provided with the extension to selectively adjust the height thereof.