US3012527A - Selector mechanism for zigzag sewing machines - Google Patents

Description

Dec. 12, 1961 w. STERNBERG 3,012,527

SELECTOR MECHANISM FOR ZIGZAG SEWING MACHINES Filed Aug. '7, 1958 2 Sheets-Sheet 1 Dec. 12, 1961 W. STERNBERG SELECTOR MECHANISM FOR ZIGZAG SEWING MACHINES Filed Aug. 7, 1958 2 Sheets-Sheet 2 3,012,527 Patented Dec. 12, 1961 ice 3,012,527 SELECTUR MECHANISM FOR ZIGZAG G MACHHNES Willi Sternberg, Karlsruhe-Durlach, Germany, assignor to Gritzner-Kayser Alrtiengesellschaft, Karlsmhe-Durlach,

Germany Filed Aug. 7, 1958, Ser. No. 753,680 Claims priority, application Germany Aug. 10, 1957 11 Claims. (Cl. 112-458) v This invention relates to sewing machines constructed to turn out decorative designs and fancy stitch patterns besides straight seams.

More particularly this invention relates to improvements in the selector mechanism which is operable for working a change-over from one pattern to another.

In such a selector mechanism a plurality of cam members or contour discs each representing the control'element for a respective stitching pattern are mounted coaxially upon a drive shaft cooperative with oscillatable means having driving connection with the needle bar guide in such a manner that the oscillatable means are oscillated selectively by a selected cam member incident to rotation of the drive shaft. The oscillatable means comprise cam follower means or feelers which can be made to cooperate with any one of the cam members, said means being constructed for imparting the oscillatory motion to be transmitted to the needle bar guide, selectively via the cam follower means.

It is one of the objects of the invention to provide means affording completely automatic stitch variations or change-over from one stitch pattern to another even during the operation of the sewing machine, and simultaneously facilitating in a positive manual control a visible change-over from one stitch pattern to another selected at will by an operator.

A more specific and important object of the invention is to provide selector means so constructed as to facilitate the arrangement and assembly of a predetermined number of different cam discs coaxially in a set or pack in a preferred sequence, yet so that even with the more fre quently employed cam discs spaced a substantial distance from each other, the followe or feeler means may be adjusted and positioned rapidly and effortless to the respective selected disc by the operator.

Accordingly, a relatively long axial distance between often employed cam discs can be significantly reduced to a very slight movement to be performed via one of the feelers by the operator.

Another object of the invention is to provide a selector mechanism resulting in a very compact sewing machine structure with a relatively reduced number of parts, of simplified construction, requiring only a unique and convenient manipulation by the operator for selecting a desired stitch pattern, and which presents a highly attractive and balanced appearance inasmuch as numerous control knobs, levers and control elements are eliminated, which have heretofore complicated the operation of known sewing machines.

Still another object of the invention is to provide a simple and effective selector mechanism whereby the selection of a certain stitch pattern among a large number of stitch designs can be carried out with great ease and accuracy in a minimum of time, due to the manipulation of a single control knob or element by the operator.

According to the invention, these objects are attained by providing a selector arrangement in which a feeler or follower unit comprising a plurality of feeler members is shiftable or slidable along a path parallel to the axis of the pack of cam discs, each of the feeler members or fingers being individually swingable on a carrier into and out of operative position relative to the respective disc, with the axial spacing of the feeler members on the carrier so arranged that each feeler when the unit is shifted axially, will cover its proportionate share of the total length or extent of the pack of discs. This shiftable feeler unit cooperates with an oscillator frame extending along the path of axial movement of the feeler unit and thus at least along the effective length of the pack, arranged to be rockable, preferably about the axis of feeler fingers for actuating the needle guide through suitable transmission means.

In order to control the operating relationship between the feeler fingers and the discs, special automatic blocking means are provided and so arranged that when the feeler unit is shifted axially to a predetermined or selected position identifying a desired stitching pattern, only one of the feeler fingers will have operative contact with the effective cam face or contour of the selected disc to rock the oscillator frame in accordance with the rotation of the pack, said frame thus actuating or oscillating the needle bar to produce the selected stitching pattern.

If preferably only two such feeler fingers are carried by the unit, they are axially spaced a distance substantially half of the effective length or extent of the pack, so that whenever one of these fingers is brought to a position relative to a selected disc, the other finger automatically becomes inoperative, and vice versa. In this way, the feeler unit need only be shifted a very short distance along the pack for effecting a change-over between cam discs or respective stitching patterns, which may be spaced at considerable axial distance from each other in the pack. Thus even in a very long pack containing a large number of discs, each disc may be reached swiftly and easily in a minimum of time by way of only a very short movement of the feeler unit by a slight turn of control knob or other manipulating element.

Features lie further in the provision of blocking means preferably in the form of a backing bar carried by the oscillator frame and presenting to the feeler fingers, opposite to the pack, a series of projections or abutments alternating with recesses both cooperating with the feeler fingers in a special manner to render them operative or inoperative as needed.

Other features reside in the provision of compact and convenient actuating means whereby the shifting of the feeler unit between stitching patterns can be readily and rapidly effected.

Still other features reside in the provision of simple and effective automatic deactivating means for rendering all feeler fingers simultaneously inoperative or neutral and clear of both the cam pack and the backing means preparatory to performing the axial shifting of the feeler unit for a change-over between stitching patterns.

These and other objects of the invention will become further apparent from the following detailed description, reference being made to the accompanying drawings showing a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a fragmentary side elevational view of the selector mechanism embodying the invention and shown partly in section; and

FIG. 2 is a top plan view, partly in section, of the mechanism of FIG. 1 showing particularly the control element and actuating means for the feeler unit.

According to a preferred embodiment and by way of example, the invention is herein illustrated in a mechanism organized for operation with only one pair of alternatingly engageable feeler fingers mounted on the slidable unit, although this arrangement does not exclude other possible arrangements providing more than two such companion feeler fingers. For example, if three were chosen the maximum shifting movement required for positioning would at no time exceed one-third of the total effective extent or length of the cam disc pack, whereas with the twin-follower or finger arrangement herein shown, the maximum shifting movement is one-half of the aforesaid total length of the pack.

Referring now particularly to the drawings, a needle bar 1 is longitudinally slidable in a known manner in a needle guide 2 having at its upper end a pivotal connection 3 with the frame of the machine, so as to be capable of swinging movements imparted thereto by a reciprocatory actuator rod 4. This actuator rod 4 is reciprocated by a guide lever 5 which has an upwardly extending arm 6 pivotally connected to one end of a link member 7 the other end of which has a pivotal connection with an oscillating frame 8.

This oscillating frame 8 is rockable upon a shaft 9 upon which is slidable or axially shiftable sleeve or carrier 10 upon which are mounted a pair of feeler fingers 11 and 12 which together with the carrier 10 constitute a feeler unit U that is shiftable axially upon the shaft 9 parallel to a drive shaft 16 carrying a pack of coaxially aligned cam members or contour discs 17 the function of which will be described below. It will be understood, however, that the feeler unit U is shiftable along the effective length of the pack of discs by suitable actuating means in the operation of the selector mechanism as will be further described.

The actuating and positioning means for shifting the feeler unit U upon shaft 9 comprises a nut 13 operating on a threaded spindle 14, and operatively so connected with the sleeve 10 of the feeler unit that rotation imparted to the spindle by the operator may move the nut 13 and sleeve 10 together parallel to the shaft 16 carrying the pack of contour or cam discs rotated by the drive of the machine.

The feeler fingers 11 and 12 are mounted turnable upon the sleeve 10, each being under the influence of spring means 18 tending to urge the fingers to a position out of contact with the discs 17 and into contact with a backing bar 19 which in this embodiment constitutes the top end member of the horizontally elongated oscillating frame 8.

The backing bar 19 is preferably in the form resembling that of a toothed rack providing along the length thereof and opposite the pack a series of projections or teeth 20 alternating with recesses 20 the spacing being such that two sequential teeth together with their two associated recesses will correspond to the spacing of the contour discs 17 carried by the shaft 16, with the teeth 20 representing abutments or projections with faces for engagement by the feeler fingers in the manner presently to be described.

The two feeler fingers 11 and 12 are formed opposite the cam disc pack with abutment edge portions 21 and 22, respectively, so arranged and shaped as to cooperate with the toothed backing bar 19 in the operation of the selector mechanism. For instance, when the feeler unit U is so positioned that the edge portion 21 of the one feeler finger registers in abutting relationship with a tooth 20 and thus in operating relationship with the selected cam disc, spring means 18 will urge the edge portion 22 of the other feeler finger 12 into a recess or gap 20 between two teeth and thus clear of the reach of the remaining cam discs and out of operative relationship therewith.

At the same time, a spring S attached to a downward arm A of he oscillating frame will tend to permanently urge the frame together with the feeler fingers towards the pack of discs.

In a practical instance this is accomplished by having the width of the abutment edges 21 and 22 correspond to one-half of the width of the discs 17, with the two feeler fingers spaced from each other half the distance of the sum total of the widths of all the discs.

In the example herein illustrating the invention there are twenty-one such discs 17 assembled in the pack or set of cams. Hence, the spacing between the feeler fingers is such that when the feeler unit is axially positioned with the feeler finger 11 registering with the first one of the discs 17, the abutment edge 21 thereof will engage the abutment face of a tooth 20 of the backing rod 19, with the second feeler finger 12 then registering with the space between the eleventh and the twelfth disc 17, and the abutment edge 22 of the finger registering with the space or recess 20*- between two teeth.

Thereupon, when the feeler finger unit U is shifted to the extent of half the width of a disc 17, such shifting will bring the feeler finger 12 into registry with the cam disc 17, whereby nose or abutment edge 22 thereof engages a tooth or projection 26, while the first feeler finger 11 will now register with a gap or recess 20 between a pair of teeth and urged by spring means 18.

Thus it will be understood that whichever feeler finger is backed by the abutment face of a tooth is thereby placed into operative position relative to the respective selected disc, whereas the companion feeler finger is angularly displaced and with its abutment edge portion lodging in a gap is thereby placed into an inoperative position relative to its opposing disc. Thus, in the sewing operation itself, a selected cam disc 17 engaged by a respective feeler finger and rotated by the drive of the machine will impart rocking movements to the oscillating frame in accordance with the contour or configuration of the disc, and such rocking movements will be transmitted through parts 7, 6, 5, 4 to the needle guide and needle bar, whereby a desired selected stitch pattern is effec tuated.

There will now be described the actuating mechanism whereby the threaded spindle 14 may be rotated for the purpose of positioning the selector means to effect a changeover from one stitch pattern to another, even without necessitating the interruption of the sewing operation.

This actuating mechanism comprises a spur gear 23 fixed on one end of the spindle, and a meshing spur gear 24 formed with a hub portion 26 carried in a journal 27 on the frame of the machine and secured against axial displacement. The gear 24 fits over a sleeve 23 rotatable about a rod 29 and carrying rotatably therewith a control knob 25 held in place by capstan 30, the sleeve with the control knob being axially displaceable in gear 24 and its hub 26.

The control knob 25 has coupling means or portions 31 adapted to interengage with complementary coupling means or portions 32 formed on the hub portion 26 of spur gear 24. It will thus be seen from FIG. 2 that depressing the control knob 25 will couple the same with gear 24, while accordingly shifting the sleeve 28 inwardly. Thereupon, the control knob 25 may be rotated so that through gears 24 and 23 the threaded spindle 14 may be turned to move the nut 13 and through coupling arm 15 to move the feeler finger unit U axially parallel to the pack of discs to a position identical to a selected stitching pattern represented by the respective disc.

However, while executing this axial shifting movement of the feeler unit, it is necessary that both feeler fingers 11 and 12 thereof be so positioned as to be clear of the discs of the pack. Mechanism to this end comprises a cam sleeve 33 constituting in effect a continuation of sleeve 28 and connected thereto as indicated by a set screw 28 or the like, and having a conically shaped terminal cam face 34 engaged by the first arm 35 of a lever element 37 formed with a second arm 38 which in turn is adapted to engage a projection or lug 39 provided upon a downward arm B of the oscillating frame 8.

Thus, when the control knob 25 is depressed, this will cause the arm 35 to ascend upon the conical cam face 34 to rest upon the adjoining cylindrical portion of sleeve extension 33, imparting to the lever element 37 a slight angular movement counter clockwise, this in turn working the oscillating frame 8 clockwise through a corresponding angle.

With the spring means 18 permanently urging both feeler fingers 11 and 12 against the backing bar 19 of the Oscillating frame, it is now clear that this angular movement imparted to the oscillating frame by the manual depression of control knob 25 will swing the feeler fingers away from the pack of discs to a position out of reach and inoperative with respect to the discs.

Yet, in order to clear the feeler fingers for axial shifting of the feeler unit, it is also necessary that the abutment edge portions 21 and 22 thereof be clear of the recesses in the backing bar 19. To this end, an abutment bar 40 is mounted on the frame of the machine extending parallel to the axis of the oscillating frame and adjacent to the backing bar 19. This abutment bar 40 is so arranged as to arrest the angular movement of the feeler fingers relative to the oscillating frame by engaging the abutment edge portions 21 and 22 thereof preferably just above the backing bar 19 while allowing the oscillating frame to continue swinging away slightly from the arrested feeler fingers a sufficient distance to ensure that they are clear of the backing bar 19 as long as the control knob 25 is depressed and coupled to the actuating mechanism.

Advantageously, the improved selector mechanism of this invention with actuating means therefor may be cooperatively associated or coupled with an indicator mechanism as disclosed in copending application Serial No. 744,555, in which a pointer moves along a scale presenting the various stitching patterns, in accordance with the positioning of the selector mechanism.

Various changes and modifications may be made without departing from the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

l. A selector mechanism for a sewing machine comprising operable knob means, an oscillatory frame, a rotatably driven shaft, a set of cam discs mounted on said shaft for rotation therewith, swingably supported feeler means interconnecting said oscillatory frame with one of said cam discs for achieving a stitch pattern corresponding to said one cam disc, said feeler means being arranged for displacement in unison lengthwise of and parallel to said shaft and including two feeler fingers arranged in spaced apart relation to each other so that when one of said feeler fingers is located in contact and in registry with one of said cam discs the other feeler finger is disposed adjacent and out of registry with another cam disc positioned at half the extent of said set of cam discs, spring means normally urging said feeler fingers out of contact with said cam discs, said oscillatory frame including a rack provided with teeth alternating with recesses, said one feeler finger engaging a respective tooth of said rack in operative position with said other feeler finger being urged by said spring means into a corresponding recess between two teeth into inoperative position so that upon rotation of said shaft on which said cam discs are mounted, said one feeler finger is agitated by the respective cam disc for translating movement of the latter via said one feeler finger and said respective tooth onto said oscillatory frame, and means operatively connected with said knob means for displacing said feeler means lengthwise of said set of cam discs for alternatingly bringing into engagement said other feeler finger with another tooth of said rack and said one feeler finger with a respective recess thereby to deactivate said one feeler finger.

2. A selector mechanism according to claim 1, including a sleeve member, elongated means mounting said sleeve member for parallel displacement to said shaft, said feeler fingers being supported by said sleeve member in said spaced apart relation, said feeler fingers being provided with respective nose-shaped ends forced under the action of said spring means toward said rack, said rack having a pitch, said pitch being predetermined so that upon displacement of said sleeve member lengthwise of said mounting means one of said feeler fingers alternates with the other feeler finger in first registering with and engaging a tooth of said rack thereby overcoming the action of said swing means for contact with a selected cam disc and then during further displacement becomes spaced from said selected cam disc for subsequent registry with a recess between two adjacent teeth thereby to deactivate said one feeler finger and engaging said other feeler finger with a respective tooth of said rack to effectuate contact of said other feeler finger with another selected disc of said set of cam discs.

3. A selector mechanism according to claim 1, wherein the distance between said two feeler fingers corresponds to about one-half of the extent of all the cam discs in pack assembled condition plus one-half of the width of a respective cam disc, the pitch of said toothed rack corresponding to said one-half of the width of said respective disc of said pack of cam discs, each feeler finger being provided with a nose-shaped end dimensioned to engage a respective recess formed between two adjacent teeth of said rack and corresponding to said pitch.

4. A selector mechanism for a sewing machine comprising, in combination, a driven shaft, a pack of rotatable cam discs carried by said shaft, each disc representing a respective stitch pattern, an oscillating frame rockable about an axis parallel to said shaft and extending at least the effective length of said pack, said frame having a plurality of teeth, at least a pair of feeler fingers having a common turning axis, at least one finger engaging one of said discs and engaging the teeth of said oscillating frame for rocking said frame upon rotation of said one disc, spring means for urging said fingers against said frame, said fingers being spaced a predetermined axial distance from each other and movable together axially as a unit parallel to said shaft as well as along said osciliating frame for positioning one of said feeler fingers for operative engagement with said selected disc, said oscillating frame and said feeler fingers being so constructed and arranged that upon rotation of said pack said one disc will through said one feeler finger rock the frame, the other of said feeler fingers being angularly displaced relative to said first mentioned finger and thereby rendered inoperative relative to said discs by passing between said teeth, and means causing said feeler fingers to be alternately and mutually exclusively engageable with a respective selected disc each within a predetermined range of the extent of the disc pack.

5. A selector mechanism for a sewing machine operable to select a stitch pattern; comprising a drive shaft, a pack of cam discs carried by said shaft and rotatable therewith, each disc representing a respective stitch pattern, an oscillating frame rockable about an axis parallel to said shaft, said frame having a plurality of teeth substantially corresponding in number to the number of said discs, a pair of feeler fingers having a common turning axis, each finger engaging selected discs of said pack, at least one finger engaging said frame, said feeler fingers being spaced a predetermined axial distance from each other and movable axially as a unit parallel to said shaft as well as along said oscillating frame for positioning one of said feeler fingers for cooperative engagement with a selected disc, spring means for permanently urging each feeler finger toward said frame and in a direction away from said disc pack, said frame teeth and said feeler fingers being so constructed and arranged that upon rotation of said disc pack the selected disc will rock the frame via said one feeler finger engaging one of said teeth, the other finger being held withdrawn by said spring means between said teeth and thereby rendered inoperative relative to said discs, whereby said feeler fingers are alternately and mutually exclusively engageable with a respective selected disc.

6. A selector mechanism for a sewing machine comprising a drive shaft, a pack of cam discs carried by said shaft and rotatable therewith, each disc representing a respective stitch pattern, an oscillating frame rockable about an axis parallel to said shaft 'and extending at least. the effective length of said pack, a pair of feeler fingers having a common rotatable axis, at least one finger engaging a selected disc as well as engaging said oscillating: frame, said fingers being spaced a predetermined axial distance from each other and movable axially as a unit parallel to said shaft as well as along said oscillating frame for positioning one of said feeler fingers at a time for cooperative engagement with a selected disc thereby to rock the frame by the rotation of the selected disc, first spring means for permanently urging each feeler finger against said frame in a direction away from said pack, second spring means for urging said frame together with said feeler fingers towards said pack of discs, and means for mutually excluding said feeler fingers from engagement by said discs and comprising a series of projections alternating with recesses provided on said frame along a length corresponding at least to the effective length of said pack and so arranged that each finger when positioned for cooperative engagement with a selected disc is backed by a projection of said series while urged by said second spring means towards said pack, while said other of said feeler fingers is angularly displaced relative to the first-mentioned finger into a respective recess of the series by the action of said first spring means.

7. A selector mechanism for a sewing machine comprising a plurality of cams rotatable on a common axis having effective side faces, an oscillatable member adjacent said cams for transmitting motion in accordance with the outline of a selected one of said cams, and follower means including at least two separate follower members selectively engageable with said cams, means supporting said follower members adjacent said cams, said follower members being shiftable along said supporting means in a direction traversing the effective side faces of said cams to align at least one of the follower members with a selected cam, and means defined on said oscillatable member located to operatively connect one of said follower members and said oscillatable member to the selected one of said cams whereby to move said oscillatable member in accordance with the outline of the selected one of said cams. said means including means located to simultaneously operatively disconnect the other of said follower members from said oscillatable member from said cams.

8. A selector mechanism according to claim 7, wherein said supporting means for said follower members includes a spindle member, said follower members being displaceable together along said spindle member.

9. A selector mechanism according to claim 7, wherein said means for selectively connecting one of said follower members includes a rack member having spaced teeth, said follower members being laterally spaced so that one of said follower members aligns with a tooth portion when the other aligns with a recess between the teeth and vice versa.

10. A selector mechanism for a sewing machine comprising a plurality of cams rotatable on a common axis, a follower shaft disposed adjacent said plurality of cams, an oscillatable member on said follower shaft for transmitting motion in accordance with the outline of a selected cam, first and second follower members slidable on said shaft and each being movable into alignment with and operative engagement with one of said cams, and means defined on said oscillatable member and located to occupy the space between one of said follower members and said oscillatable member connecting one of said members to said oscillatable member and the selected one of said cams for transmission of the motion of the cam outline of which the follower is in contact and located to clear the space between the other of said follower members and said oscillatable member.

11. A selector mechanism according to claim 10, wherein said means defined on said oscillatable member includes a rack having spaced teeth thereon, the spacing being such that the teeth contact one of said follower members when the other of said follower members lies in a space between the teeth.

References Cited in the file of this patent UNITED STATES PATENTS 2,675,451 Tinus Apr. 13, 1954 2,747,417 Brown May 29, 1956 2,764,895 Bono Oct. 2, 1956 2,832,302 Gegauf Apr. 29, 1958 2,862,468 Johnson 2. Dec. 2, 1958 FOREIGN PATEITS 19,184 Great Britain Sept. 12, 1908 1,095,914 Great Britain Dec. 29, 1954 548,344 Italy Sept. 24, 1956 1,004,465 Germany Mar. 14, 1957

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