US2823632A - Needle-bar jogging mechanisms for sewing machines - Google Patents

Description

Feb. 18, 1958 J. D. GARA'SIMOWICZ 2,823,632

NEEDLE-BAR JOGGING MECHANISMS FOR SEWING MACHINES Filed March 15, 1955 2 She ets-Sheet 1 INVENTOR John 0. Gums/monk! WITNESS Feb. 18, 1958 J. GARASIMOWICZ 2,323,632

NEEDLE-BAR JO-GGING MECHANISMS FOR SEWING MACHINES Filed March 15, 1955 2 Sheets-Sheet 2 a a: l

I INVENTOH John D. Garasimowicz WITNESS BY United States Patent M NEEDLE-BAR JOGGING MECHANISMS FOR SEWING MACHINES John D. Garasimowicz, Bridgeport, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. 5.,

. a corporation of New Jersey Application March 15, 1955, Serial No. 494,351

4 Claims. (Cl. 112-158) This invention relates to sewing machines, and more particularly, to mechanisms for jogging one or more of the stitch-forming instrumentalities of a sewing machine between successive needle penetrations to effect the formation of a pattern of stitches.

It is an object of this invention to provide a jogging mechanism for the stitch forming instrumentalities of a sewing machine which may be accommodated conveniently within the customary frame of a sewing machine.

Another object of this invention is to provide a jogging mechanism of the above character in which the effect, at the instrumentalitiy being jogged, of the accumulation of tolerances between the parts of the jogging mechanism will be minimized.

Still another object of this invention is to provide a mechanism for jogging one or more of the stitch forming instrumentalities of a sewing machine utilizing, in a novel manner, a form of construction which facilitates mass production manufacture of the parts to uniform tolerances and in which wear between interacting parts of the mechanism effects a minimum of play or idle movement at the needle-bar.

With the above and additional objects and advantages in view, as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

Fig. 1 represents a side elevational view of a sewing machine partly in vertical cross section and having my improved mechanism applied to the needle-bar thereof,

Fig. 2 represents a cross-sectional view taken substantially along line 2-2 of Fig. l, and

Fig. 3 represents a cross-sectional view taken substantially along line 3-3 of Fig. 1.

Referring more particularly to the drawings, my invention is illustrated as applied to the needle-bar jogging mechanism of a button sewing machine. The sewing machine in other respects is of a conventional type in which both a needle 11 and a work-holding clamp 12 are jogged during operation, thus providing relative movements therebetween to effect a pattern of stitches passing alternately through different holes of a button.

The machine frame comprises a bed 13, a standard 14, and a hollow bracket-arm 15 which extends over the bed and is closed at its free extremity by and end cover 16 and a top cover 17. Journaled in the bed is a main shaft 18 which may be driven in well known fashion by a pulley 19 thereon. By way of a belt 20, the main shaft serves to rotate a needle-bar driving shaft 21 journaled in the bracket-arm. The shaft 21 carries a crank 22 which reciprocates a needle-carrying bar 23 endwise by means of a needle-bar driving link 24. The needlebar is journaled for endwise reciprocation in the vertically spaced arms 2525 of a gate member 26 which carries vertically spaced pintle pins 27-28 journaled in the bracket-arm. The driving link 24 carries a block 29 which slidably engages a slotted cross head 30 fast on the needle-bar so that the needle-bar may be jogged about 2,823,632 Patented Feb. 18, 1958 the vertical axis of the pintle pins 27-28 without interference with the operation of the needle reciprocating mechanism.

Driven from the main shaft 18 by means of a worm 31 and a wheel 32 is a vertically arranged cam shaft 33 which carries a pattern cam 34 in the bed and a pattern cam 35 in the bracket-arm. The pattern cam 34 serves by means of follower linkage, as is well known in the art, to jog the work-holding clamp 12 and may also be used to jog the lower stitch forming instrumentalities (not shown) in a timed relation corresponding to jogging movements of the needle. The upper pattern cam 35 is grooved, as at 36, so as to control the work-jogging movements of the needle as will now be described.

Fixed in a web 40, which extends from the bracketarm into the hollow standard, is a fulcrum pin 41 upon which a follower lever 42 is journaled. The fulcrum .pin 41 is disposed adjacent the rear wall of the bracket-arm at the opposite side of the cam shaft 33 from the needlebar, and the follower lever extends toward the needlebar and over the pattern cam 35 on the cam shaft 33. The follower lever is formed with a cylindrical bore 43 and with a laterally extending ear 44 which carries a follower pin 45 disposed to track the pattern cam groove 36. Freely slidable in the cylindrical bore 43 of the follower lever is one portion 45 of an articulated slide rod of which the other portion 47 extends into a split clamp 43 formed at the extremity of a lever arm 49 which is secured to the pintle pin 27 of the needle-bar gate.

The slide rod portions 46 and 47 are joined by a pair of interleaved clevises 50 and 51 secured one to each of the slide rod portions and pivotally connected by means 7 of a knuckle pin 52 held in place by a pair of spring clips 5353.

The split clamp 48 is provided with a clamp screw 54 so that the portion 47 of the articulated slide rod 46-47 may be clamped in any selected axial position with respect to the split clamp, thus providing a range of selected positions of the knuckle pin 52 between the follower pin 45 and the needle-bar gate pintles 27, 28 by which adjustments of the extent or bight of the needle jogging movements may be attained. By adjusting .the knuckle pin to a position nearer the needle-bar gate pintles, the bight of needle-bar jogging movement will be increased.

The follower lever 42 and the slide rod portion 46 combine to provide a driving lever of the third class having a fulcrum 41 at one side of the cam shaft 33, deriving motion from the follower pin 45, and delivering the motion at the knuckle pin 52. The slide rod portion 47 together with the needle-bar gate 26 combine to provide a lever of the first class adapted to transmit motion from the knuckle pin 52 to the needle-bar. One advantage provided by this arrangement resides in the fact that the tolerances of the fits between relatively moving parts in the needle-jogging mechanism have a minimum accumulated effect at the needle-bar. With current production methods, the expense involved in halving the tolerances between moving parts would be appreciable. The present needle-bar jogging mechanism inherently eifects a reduction of approximately one-half in the effect of accumulated tolerances or play at the needle-bar resulting from the clearances at the fulcrum pin 41, the knuckle pin 52, and the needle-bar gate pintles 27, 28, as compared with the customary needle-bar jogging mechanisms which utilize two levers of the first class. In terms of measurable play at the needle-bar, therefore, the present construction provides an effect which is the equivalent of halving the tolerances of each of the fits between moving parts of the prior forms of construction.

Each of the relatively moving surfaces in the construction of the present invention are cylindrical in form and,

therefore, are readily and economically manufacturable to uniformly high tolerance standards. Moreover, the use of a sleeve-like follower lever 42 is advantageous in that the generous bearing surface which is thus available for the sliding fit between the slide rod portion 46 and the cylindrical bore 43 in the follower lever reduces the wearing efiect between these parts and provides a marked increase in the usable life of this form of needlejogging mechanism.

Having thus set forth the nature of the invention, what I claim herein is:

1. In a sewing machine having a frame, stitch forming instrumentalities and actuating mechanism for said instrumentalities carried in said frame, mechanism for jogging at least one of said instrumentalities to effect the formation of a pattern of stitches comprising, a driven lever of the first class operatively connected at one extremity to said stitch forming instrumentality to be jogged, a driving lever of the third class pivotally connected at one extremity to said driven lever, a fulcrum carried by said sewing machine frame and disposed operatively to engage said driving lever at its opposite extremity, means on said driving lever for freely varying the length thereof between said extremities during jogging movement of said driving lever, and means driven by said sewing machine actuating mechanism and adapted to engage said driving lever between said extremities thereof for imparting jogging movements thereto.

2. In a sewing machine having a frame, stitch forming instrumentalities and actuating mechanism for said instrumentalities carried in said frame, mechanism for jogging at least one of said instrumentalities to effect the formation of a pattern of stitches comprising, a grooved rotatable pattern cam member adapted to be driven by said sewing machine actuating mechanism, a follower lever of the third class fulcrumed at one extremity in said machine frame on that side of the axis of pattern cam rotation opposite said stitch forming instrumentality to be jogged, a cam follower carried by said follower lever and disposed to track said pattern cam groove, a driven lever of the first class fulcrumed in said machine frame, and operative connections between said driven lever at one extremity with said follower lever, and at the opposite extremity with said stitch forming instrumentality to be jogged.

3. In a sewing machine having a frame, an endwise reciprocable needle-bar, actuating mechanism carried in said frame for reciprocating said needle-bar, and mecha- 4,, nism for imparting translatory sidewise jogging motion to said needle-bar comprising, a needle-bar gate in the form of a lever of the first class, spaced arms formed on said gate defining a first lever arm in which said needle-bar is journaled for endwise reciprocation, means pivoting said needle-bar gate to said machine frame on an axis parallel to the direction of needle reciprocation, a lever arm extending from said needle-bar gate pivoting means, a follower lever of the third class, a fulcrum carried by said machine frame and disposed operatively to engage one extremity of said follower lever, an operative motion transmitting connection between the opposite extremity of said follower lever and said needle-bar gate lever arm,

a grooved pattern cam disk carried for rotation in said machine frame on an axis parallel to that of said follower lever fulcrum, and a pattern-cam follower carried by said follower lever between said extremities.

4. In a sewing machine having a frame, an endwise reciprocable needle-bar, sewing machine actuating mechanism carried in said frame and adapted to reciprocate said needle-bar, and mechanism for imparting translatory sidewise jogging motion to said needle-bar comprising, a needle-bar gate, a pivot for said gate carried by said frame on an axis substantially parallel to that of said needle-bar, said needle-bar being slidably supported in said gate at one side of said pivot, a lever arm extending from said gate at the opposite side of said pivot, an articulated slide rod including a first and a second rod portion and a knuckle pin joining said portions, clamp means carried by the lever arm of said needle-bar gate and serving to secure said first rod portion thereto in selected axial position, said second slide rod portion being cylindrical in form, a driving lever formed with a cylindrical bore adapted slidingly to accommodate said second slide rod portion, means pivoting one extremity of said driving lever to said frame, and mechanism driven by said sewing machine actuating mechanism and adapted to engage said driving lever at a point intermediate said pivoted extremity and said knuckle pin for imparting needle-bar jogging movements thereto.

References Cited in the file of this patent UNITED STATES PATENTS 1,671,197 Lyons May 29, 1928 1,991,627 Reece Feb. 19, 1935 2,298,246 McCann Oct. 6, 1942 2,311,194 Wood Feb. 16, 1943

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