US3670974A

US3670974A - Releasable winding mechanism for sewing machines

Info

Publication number: US3670974A
Application number: US108517A
Authority: US
Inventors: Odette Ueltschi
Original assignee: Fritz Gegauf AG
Current assignee: Fritz Gegauf AG
Priority date: 1970-02-06
Filing date: 1971-01-21
Publication date: 1972-06-20
Anticipated expiration: 1989-06-20
Also published as: SE364534B; CH512621A; ES388009A1; DE2101140A1; GB1343702A; ATA16271A; FR2078167A5; AT326988B

Abstract

The winding mechanism is used with sewing machines of the type having a fixedly positioned winder shaft with a bobbin-receiving pin protruding from the machine casing, and a friction wheel for driving the winder shaft and having a friction wheel shaft separated from the winder shaft but operatively connected with the winder shaft and engageable with the driving wheel of the machine to selectively operate the winding mechanism. The inner end of the winder shaft has fixed thereto a disk with a slot extending diametrically thereof, and an end of the friction wheel shaft carries a cooperating disk having a pin or lug engageable in the slot. The friction wheel is mounted on a carrier which is spring biased to an operating position and a rest position. The driving connection between the two shafts is maintained at all times within the range of displacement of the friction wheel shaft between the operating and rest positions.

Description

United States Patent [15] 3,670,974

Ueltschi 1 June 20, 1972 [s41 RELEASABLE WINDING MECHANISM 2,933,455 5/1961 Herbst ..242/22 FOR SEWING MACHINES [72] Inventor: Odette Ueltschi, Steckborn, Switzerland [73] Assignee: Fritz Gegauf AG Bernina-Nahmaschlnenfabrik, Steckbom, Switzerland [22] Filed: Jan. 21, 1971 [21] Appl. No.: 108,517

[30] Foreign Application Priority Data Feb. 6, 1970 Switzerland ..1780/70 [52] US. Cl. ..242/22, 112/218 A [51] Int. Cl. ..B65h 54/18, D05b 59/00 [58] Field of Search ..242/54, 20, 22, 23; 112/218 A; 287/2, 129, 130; 74/194, 206; 64/8, 10, 31

[56] References Cited UNITED STATES PATENTS 935,263 9/ 1909 Chapelle "242/22 2,148,975 2/1939 Agren 2,836,371 5/1958 Ayres ..242/22 3,581,687 6/1971 Meieret al.... ..112/218A Primary Examiner-Stanley N. Gilreath Assistant Examiner-Werner H. Schroeder Attorney-John J. McGlew and Alfred E. Page ABSTRACT The winding mechanism is used with sewing machines of the type having a fixedly positioned winder shaft with a bobbinreceiving pin protruding from the machine casing, and a friction wheel for driving the winder shah and having a friction wheel shaft separated from the winder shaft but operatively connected with the winder shaft and engageable with the driving wheel of the machine to selectively operate the winding mechanism. The inner end of the winder shaft has fixed thereto a disk with a slot extending diametrically thereof, and an end of the friction wheel shaft carries a cooperating disk having a pin or lug engageable in the slot. The friction wheel is mounted on a carrier which is spring biased to an operating position and a rest position. The driving connection between the two shafts is maintained at all times within the range of displacement of the friction wheel shaft between the operating and rest positions.

10 Claims, 6 Drawing Figures PATENTEDJUHZO 1972 3,57 ,97

SHEEI 1 BF 3 INVENTOR. ODETTE \IELTS 'L 1 RELEASABLE WINDING MECHANISM FOR SEWING MACHINES BACKGROUND OF THE INVENTION There are known sewing machine winding mechanisms which are attached to the sewing machine on that side of the machine arm facing the operator and close to the driving wheel. As a rule, these winding mechanisms include a winder arm which can be pivoted in a vertical plane and which serves as a carrier for the winder shaft which is provided with a friction wheel for driving the same. Such winding mechanisms are completely external to the sewing machine casing, and render the cleaning of the sewing machine difficult as well as considerably impairing the esthetic effect of a modern sewing machine.

There are also known winding mechanisms, for sewing machines, which are arranged under a hinged cover or which can be swung into the interior of the machine casing when not in use so that, in rest position, they are covered by a cover. However, these winding mechanisms are very cumbersome to operate and, as they require a relatively large manufacturing apparatus, are consequently expensive.

Other known winding mechanisms for sewing machines are arranged on, the arm cover of the machine, or on the side of the machine facing the operator. As a rule, these usually comprise a winder arm which can be moved toward the driving wheel, and which carries the winder shaft with the friction wheel and the bobbin-receiving pin protruding from the sewing machine casing. These winding mechanisms are spring biased on their operating position and in their rest position, and are more and more preferred in sewing machines. However, the displaceability of the winder shaft relative to the driving wheel requires a corresponding large breakthrough or opening in the sewing machine casing. Apart from the fact that the esthetic effect of the sewing machine is impaired, the fuzz or lint formed during the winding of the thread can easily enter through the breakthrough into the interior of the sewing machine casing. Due to their arrangement on the sewing machine, these winding mechanisms also have the disadvantage that the tension of the thread, formed during winding of the thread from a supply bobbin to a looper thread bobbin, counteracts the contact pressure of the friction wheel on the driving wheel and necessary to drive the friction wheel. The contact pressure thus can be reduced to such an extent, under unfavorable circumstances, for example, when unwinding the thread from a large supply bobbin, that it is no longer sufficient for reliable drive of the friction wheel.

Winding mechanisms with a fixedly positioned but axially displaceable winder shafts are known and do not have the above-mentioned disadvantages. However, in these winding mechanisms, the bobbin-receiving journal protrudes from the sewing machine housing in its rest position, with the protrusion increased by the amount of the axial displacement. In addition, when the winding mechanism is connected, a locking finger of the lever sensing the amount of wound thread moves over a lug of the winder shaft and thus keeps the shaft in the connected position. The sensing lever grazes, during the winding process, constantly on the lug of the winder shaft, so that annoying noises are produced and those parts rubbing against each other are rapidly worn out.

In another known winding mechanism with axially displaceable winder shafts, the sensing lever bears against a flange of the thread bobbin to be wound, and thus keeps the winder shaft in its operating position. This axial limitation of the winder shaft also causes annoying grazing noises and rapid wear of the parts rubbing against each other. Under unfavorable conditions, for example, with unilateral winding of the thread of the looper thread bobbin, the thread even can be clamped between the bobbin flange and the sensing lever hearing against the latter, and thus can be damaged.

SUMMARY OF THE INVENTION This invention relates to releasable winding mechanisms for sewing machines and, more particularly, to a releasable winding mechanism of the above-mentioned type and which does not have the disadvantages of the mentioned known winding mechanisms.

In accordance with the invention, the winding mechanism is characterized by the fact that the axis of the friction wheel shaft is displaceable laterally with respect to the axis of the fixedly positioned winder shaft, for starting and stopping the winding mechanism, and the driving connection between the two shafts is maintained at all times within the displacement range of the friction wheel axis necessary for movement between the operating position and the rest position.

The winding mechanism embodying the invention is very easy to operate, and fits harmoniously into the outer form or contour of the sewing machine casing, since the bobbinreceiving pin has to project from the casing only by the very small height of the sensing lever which is necessary in any case, and can be covered almost completely by this lever. Since no breakthroughs or openings are required in the sewing machine casing within the range of the winding mechanism, penetration of dust and fun or lint into the interior of the easing is effectively prevented. Another advantage is that the contact pressure of the friction wheel on the driving wheel cannot be influenced by the tension of the thread to be wound.

An object of the invention is to provide an improved releasable winding mechanism for sewing machines.

Another object of the invention is to provide such a releasable winding mechanism in which the esthetic appearance of the sewing machine casing is not impaired and all the parts are disposed within the casing.

A further object of the invention is to provide such a winding mechanism in which there are no uncovered openings in the sewing machine casing, thus preventing entry of dust and lint or the like into the casing.

Another object of the invention is to provide such a winding mechanism which is simple in construction, easy to operate, and inexpensive to manufacture.

For an understanding of the principles of the invention, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a partial elevation view of a sewing machine with a winding mechanism, embodying the invention, built into the arm cover;

FIG. 2 is a partial top plan view of the sewing machine illustrating the arrangement of the winding mechanism and the course of the thread during winding;

FIG. 3 is a sectional view taken along the line I-[ of FIG. 2 and illustrating the winding mechanism in its operating position;

FIG. 4 is a view similar to FIG. 2 but illustrating the winding mechanism in its rest position;

FIG. 5 is a sectional view taken along the line II-II of FIG. 2 illustrating the winding mechanism in its operating position; and

FIG. 6 is a top plan view of the winding mechanism with the arm cover partly cut away and the winder shaft removed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, a sewing machine is illustrated as having an arm 1 provided with an arm cover 2, and as being driven by known driving means, not shown, through a driving wheel 3. Driving wheel 3 is operatively connected, in a known manner, with the arm (not shown) of the sewing machine, and can be released selectively from such connection, by means of a release screw 4, so that driving wheel 3 can rotate on the arm shaft without driving the latter. The usual operating or control elements of the sewing machine are illustrated at 5, 6 and 7.

A winding mechanism 8, embodying the invention, is arranged close to driving wheel 3, in arm cover 2. Thread 9 is unwound from a supply bobbin 11 arranged on a yarn roll holder 10, is conducted around a guide pin 12, which can also be designed as a thread pretensioning means, and is wound on looper thread bobbin 13. Bobbin 13 is arranged on the slotted bobbin-receiving pin 14 of a winder shaft 15 protruding from arm cover 2. Winder shaft 15 is freely rotatable in a hub 16 integral with arm cover 2, and is secured against axial displacement by a lug 17 and a locking ring 18. Shaft 15 has a mounting portion 46 at its bottom end, on which there is nonrotatably mounted a driving disk 19 formed with a driving slot 20.

A friction wheel shaft 21 is freely rotatable on a hub 22 of a winder arm 23, and is secured against axial displacement by the hub 24 of a friction wheel 25, hub 24 being pressed on a mounting portion'49 at the bottom of friction wheel shaft 21. Friction wheel 25 is vulcanized, in a known manner, on hub 24, or is secured thereon in any other way. The top end of friction wheel shaft 21 has a mounting portion 46 on which there is non-rotatably secured a driving disk 27 provided with a driving pin 28 which engages slot of disk 19, thus establishing the driving connection between friction wheel shaft 21 and winder shaft 15. Winder arm 23 is pivotally secured with a setscrew'29 on a bearing block 30 of cover 2, for pivoting in a horizontal plane about the axis of setscrew 29, and is biased by a helical tension spring 31 toward driving wheel 3. The other end of spring 31 is secured on a depending bolt 43 screwed into cover 2.

A lever 32, which senses the amount of thread wound on looper thread bobbin 13, is pivotally secured by a setscrew 33 on release arm 34 for swinging about the axis of screw 33, and is guided in a slot 35 in arm cover 2. Release arm 34 is pivotally secured, for swinging in a horizontal plane, by a setscrew 36 secured to arm cover 2, and its free end carriesa control pin 37. A leafspring 40 is adjustably mounted on arm cover 2 through the medium of

screws

38 and 39, and is formed with a striking ramp 41 and, in the rest position of winding mechanism 8, has its free end pressing against winder arm23. The force exerted by leafspring 40 is greater than the tension of helical spring 31, so that leafspring 40 holds winding mechanism 8 in its rest position and out of engagement with driving wheel 3.

In the operating position of winding mechanism 8, leaf-v spring 40 is pushed away from winder arm 23 by control pin 37 of release arm 34, so that spring 31 can pull winder arm 23, with friction wheel rotatably mounted therein, toward driving wheel 3, and thus establish the operating connection between driving wheel 3 and friction wheel 25. Ramp 41 of spring 40 serves,'on the one hand, to push leafspring 40 away from winder arm 24 during the starting of winding mechanism 8 and, on the other hand, to release winding mechanism 8 by pushing control pin 37, secured on release arm 34, away when looper thread bobbin 13 is full. Slot 42 in leafspring 40 permits an exact adjustment of the release moment of the winding mechanism, by loosening and then retightening the two

screws

38 and 39.

The lateral movement of friction wheel shaft 21 relative to winder shaft 15 is so limited by stops 44 and 45, integral with arm cover 2, that driving pin 28 of driving disk 27 cannot be disengaged from slot 20 of disk 19.

Disks

27 and 19 preferably are made of plastic composition material, and are press fitted on the notched mounting

portions

46 and 47 of winder shaft 15 and friction wheel shaft 21, respectively.

Winding mechanism 8 normally is in its rest position as illustrated in FIG. 4. In order to supplement the looper thread supply, looper thread bobbin 13 is attached on bobbin-receiving pin 14 of mechanism 8. The slotted bobbin-receiving pin 14 provides a non-rotational connection between winder shaft 15 and looper thread bobbin 13, since the lightly spread bobbin-receiving pin 14 is clamped firmly in bore 48 of looper thread bobbin 13. The thread 9, to be wound, is now lead from supply hohbin 11 around guide pin 12 to bobbin 13, and wound by hand several turns clockwise around the latter.

To start winding mechanism 8, sensing lever 32 is pushed along slot 35 of cover 2 against bobbin 13, and release arm 34 thus is turned about the axis of setscrew 38 toward winder shaft 13. Control pin 37 strikes against ramp 41 of leafspring 40 and pushes spring 40 away from winder arm 23, so that winder arm 23 is turned, under the action of helical spring 31, about the axis of setscrew 20 serving as a pivot, and toward driving wheel 3 until friction wheel 25 bears against driving wheel 3. During the further rotation of release arm 34, until it bears on sensing lever 32 at the end of slot 35 in arm cover 2, control pin 37 strikes against a part of leafspring 40 extending substantially at a right angle to release arm 34. Spring 40 now acts on control pin 37 of release arm 34 in a manner such that arm 34, with sensing lever 32 secured thereon and protruding between the flanges of looper thread bobbin 13, is secured by leafspring 40 against accidental displacement.

In this position of winding mechanism 8, which is shown in FIGS. 3 and 6, friction wheel shaft 21 rotates substantially concentrically with fixedly positioned winder shaft 15. Since driving disk 27 and driven disk 19 can be turned easily relatively to each other, the lateral displaceability of the axis of friction wheel shaft 21, relative to the axis of winder shaft 15,

is independent of the radial position of slot 20 and of driving pin 28 engaged therein, so that the winding mechanism can be started and stopped in any radial position of slot 20.

Depending on whether the thread supply on thread looper bobbin 13 is to be supplemented without interruption of the sewing operation, or whether the operator wishes to supervise the winding operation, driving wheel 3 can be disengaged from the work by means of release screw 4, or can remain engaged. The winding of looper thread bobbin 13 is effected in a known manner.

Before bobbin 13 is completely filled with thread, the wound thread begins to push sensing lever 32 away from bobbin 13. Release arm 34, with control pin 37, thus is slowly turned away from winder shaft 15 until control pin 37 engages ramp 41 of leafspring 40. As soon as pin 37 has reached ramp 41, leafspring 40 exerts, on control pin 37 of release arm 34, a laterally directed force component, under whose action release arm 34 returns rapidly into its rest position, representing in FIG. 6 in broken lines. In the rest position, sensing lever 32 bears against the end of slot 35 in cover 2, and cover slot 35 completely in any of its possible positions. As soon as leafspring 40 is no longer held away from winder arm 23 by control pin 37, it again exerts its pressure on the winder arm and turns winder arm 23, against the tension of spring 31, about the axis of setscrew 29 which acts as a pivot and away from driving wheel 3 into the rest position, thus interrupting the winding process. V I

Naturally, the embodiment of the winding mechanism, as described can be modified. Thus, for example, driving pin 28 could engage a sufficiently large bore in disk 19 instead of a slot therein. The transmission of the movement also could be effected by two driving cams engaging each other. It is further possible to design winder arm 23 and release arm 34 as rectilinearly moving slides instead of as pivotal levers. Naturally, the winding mechanism embodying the invention also could be arranged on any other part of the sewing machine, for example on the face of the sewing machine arm facing the operator.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. In a releasable winding mechanism for sewing machines of the type having a fixedly positioned winder shaft with a bobbin-receiving pin protruding from the machine casing, a friction wheel, driving the winder shaft, mounted on a friction wheel shaft separated from the winder shaft but operatively connected with the winder shaft, and a driving wheel, with the friction wheel being arranged-to be operatively connected to the driving wheel to operate the winding mechanism, the improvement comprising, in combination, means mounting said friction wheel shaft for displacement of its axis laterally, relative to the axis of said fixedly positioned winder shaft, between a winding mechanism operating position and a rest position; and connection means constantly maintaining the driving connection between said shafts throughout the range of displacement of said friction wheel shaft between said operating and rest positions.

2. In a releasable winding mechanism for sewing machines, the improvement claimed in claim 1, in which said mounting means for said friction wheel shaft comprises a carrier moving between a starting position and a stopping position; and means spring biasing saidcarrier to both said positions.

3. In a releasable winding mechanism for sewing machines, the improvement claimed in claim 2, a feeler protruding from the machine casing and engaging the thread mounted on a bobbin, said feeler being operable to shift said carrier from one spring bias to the other spring bias.

4. In a releasable winding mechanism for sewing machines, the improvement claimed in claim 3, including a feeler carrier movably mounted in the machine casing and, in said operating position, maintaining a first spring out of engagement with said carrier of said friction wheel shaft; a second and weaker spring acting on said carrier of said friction wheel shaft in a direction opposite to said first spring in said operating position; said feeler carrier, in the rest position, releasing said first spring to bias said carrier of said friction wheel shaft to the inoperative rest position and against the bias of said second spring.

5. In a releasable winding mechanism for sewing machines, the improvement claimed in claim 1, in which said connection means comprises a pin extending outwardly from one of said shafts and eccentric thereto, and a slot extending diametrically of the adjacent end of the other shaft and having said pin engaged therein.

6. In a releasable winding mechanism for sewing machines, the improvement claimed in claim 1, in which said connection means comprises a pin extending outwardly from one end of one of said shafts and eccentric thereto, and an eccentric bore in the facing end of the other shaft having a diameter larger than that of said pin and having said pin engaged therein.

7. In a releasable winding mechanism for sewing machines, the improvement claimed in claim 1, in which said connection means comprises respective frontally rotating cams on said shafts and in engagement with each other.

8. In a releasable winding mechanism for sewing machines, the improvement claimed in claim 1, in which said connection means comprises plastic composition members.

9. In a releasable winding mechanism for sewing machines, the improvement claimed in claim 1, in which said shafis have facing ends; each cam having a disk secured to its facing end; one of said disks having a pin extending from its outer surface eccentrically thereof and the other of said disks having a diametric slot engaging said pin.

10. In a releasable winding mechanism for sewing machines, the improvement claimed in claim 4, in which said first spring comprises a leafspring having a free end engageable with said carrier for said friction wheel shaft, and having a ramp portion intermediate its ends; said feeler carrier having a pin at its free end engageable with said first spring and being moved by said feeler to a position in which said pin engages said ramp portion for biasing of said pin and said feeler carrier to said rest position, releasing said leafspring to engage said carrier for said friction wheel shaft.

In a releasable winding mechanism for sewing machines, the improvement claimed in claim 4, in which said first spring comprises a leafspring having a free end engageable with said carrier for said friction wheel shaft, and having a ramp portion intermediate its ends; said feeler carrier having a pin at its free end engageable with said first spring and being moved by said feeler to a position in which said pin engages said ramp portion for biasing of said pin and said feeler carrier to said rest position, releasing said leafspring to engage said carrier for said friction wheel shaft.

Claims

1. In a releasable winding mechanism for sewing machines of the type having a fixedly positioned winder shaft with a bobbinreceiving pin protruding from the machine casing, a friction wheel, driving the winder shaft, mounted on a friction wheel shaft separated from the winder shaft but operatively connected with the winder shaft, and a driving wheel, with the friction wheel being arranged to be operatively connected to the driving wheel to operate the winding mechanism, the improvement comprising, in combination, means mounting said friction wheel shaft for displacement of its axis laterally, relative to the axis of said fixedly positioned winder shaft, between a winding mechanism operating position and a rest position; and connection means constantly maintaining the driving connection between said shafts throughout the range of displacement of said friction wheel shaft between said operating and rest positions.

2. In a releasable winding mechanism for sewing machines, the improvement claimed in claim 1, in which said mounting means for said friction wheel shaft comprises a carrier moving between a starting position and a stopping position; and means spring biasing said carrier to both said positions.

9. In a releasable winding mechanism for sewing machines, the improvement claimed in claim 1, in which said shafts have facing ends; each cam having a disk secured to its facing end; one of said disks having a pin extending from its outer surface eccentrically thereof and the other of said disks having a diametric slot engaging said pin.