US3496892A - Auxiliary feeding device in sewing machines - Google Patents

Description

Feb. 24,1970 N. MARFORIO 3,496,892

AUXILIARY FEEDING DEVICE IN SEWING MACHINES I Filed June 26, 1967 2 Sheets-Sheet 1 INVENTO R NeRIUo MAR Forero ATTORNEY$ Feb. '24, 1970 N. MARFORIO 2 AUXILIARY FEEDING. DEVICE IN SEWING MACHINES Filed June 26, 1967 2 Sheets-$heet 2 r ,41=iwm Wm 11+ 44 M 'sig I m, rm, 42 Eb I. I

ATTORNEYS 3,496,892 AUXILIARY FEEDING DEVICE IN SEWING MACHINES Nerino Marforio, Milan, Italy, assignor to S.p.A. Virginio Rimoldi & C., Milan, Italy Filed June 26, 1967, Ser. No. 648,846

Claims priority, application Italy, July 27, 1966,

17,375/ 66 Int. Cl. Db 27/06 US. Cl. 11218 8 Claims ABSTRACT OF THE DISCLOSURE In a sewing machine, a pair of fabric feed rollers arranged following a pair of feed cups along the line of fabric travel, and a drive means for driving both rollers in synchronism with the cups in stepwise rotative fashion.

This invention relates to an auxiliary feeding device in sewing machines which are chainstitch, overlook, lockstitch machines and the like, provided with two rollers and two cups, the latter being placed before the former in the direction of feed, said cups being adapted for feeding the work to be sewn, one of which cups transmits one-way step-by-step motion to means provided within the overhanging bracket of the frame of the machine, which means transmit the one-way step-by-step motion to the other cup in a direction opposite to the direction of th one cup.

Auxiliary feeding means are known in which the rotation of two rollers arranged to pull the stitching chain and to feed the Work pieces as they are sewn and held together by the chainstitch, is caused by gears which are meshed directly with serrated cups.

Further, chainstitch pulling devices are known, which comprise a roller driven by one of the cups, as above described, and a presser having a yielding sole in contact with the roller. Said presser is also integral with the axis of rotation of the other cup and has the disadvantage that on tilting said axis for shifting the cups away from each other, also the sole tilts relative to the cylindrical surface of the roller, so that the contact zone between sole and roller is reduced and consequently the chainstitch and the work are not well gripped and, because of the weight of the latter, move downwards with the possibility existing of missing the stitches to be formed by the stitch forming devices.

One of the objects of this invention is to provide an 0 auxiliary feeding device, which eliminates the above mentioned disadvantages and wherein the chain pulling rollers may be interchanged with others of different diameter and different knurl pattern to suit the particular work fabric which is to be sewn, the different diameters corresponding to different peripheral speeds.

Another object of this invention is to provide a device in which the shifting of the outer cup away from the inner one is independent of the shifting of the outer roller away from the inner one so that at the beginning of the seam the chain may still be gripped by the rollers although the cups may be separated from each other for inserting the work piece therebetween.

The foregoing objects are realized in the present invention by means of an arrangement whereby the two rollers are driven in opposite directions relative to each other but respectively in synchronism with the cups and at a distance therefrom and without any driving mechanisms being interposed between the cups and the rollers. Specifically, the present invention provides a driving arrangement comprising two vertical shafts mounted in the overhanging arm of the machine and each transmitting motion States Patent 0 to a respective one of the rollers, said motion being stepwise and in synchronism with that of the respective cups.

Other objects and advantages will become apparent from the description now to follow, of a preferred em bodiment thereof shown by way of example in the accompanying, partly diagrammatic, drawings, in which:

. FIG. 1 is a perspective view of the mechanism accordmg to the invention driving the auxiliary feeding device.

FIG. 2 is a partly sectioned side view of the mechanism of FIGURE 1.

FIG. 3 is a horizontal section view along the line 33 in FIGURE 2.

The sewing machine relating to this invention comprises a frame 1 having on the top an overhanging arm 2 and forming a housing for enclosing respective operating elements of the machine and permitting automatic lubrication thereof, and supporting a horizontally disposed reciprocable needle bar (known and not shown in the drawings) which stands just over inner and outer feed cups 3 and 4 and cooperates with a looper 5 and a hook 6, which are suitable devices for forming the stitches.

A flywheel 7 which is connected, as known, and not shown in the drawings, with a machine-operating electric motor, is carried by a main shaft 8 which is connected with an eccentric 9 which is engaged in the hole of a strap 10 of a pitman 11.

Another strap 12 of said pitman 11 is pivoted by a stud 13 at an end of a rocker arm 14 rocking about a shaft 15, whilst the other'end of said rocker arm 14 is pivotally connected to link 16 by means of a stud 17.

Said link 16 is connected with a known one way clutch 18, transforming the rocking motion of said link in a oneway step-by-step rotary motion in the direction of arrow A which is transmitted to an inner feed shaft 19 on which the inner feed cup 3 is fixed. Upon said shaft 19 beyond the cup 3 a gear 20 is keyed, meshing with a gear 21 integral with an upright shaft 22 upon which another gear 23 is keyed, which is located within the overhanging arm 2 of the sewing machine.

Meshing with said gear 23 there is an intermediate gear 24 keyed upon a spindle 25. A gear 26 meshes with said intermediate gear 24 and is keyed upon a shaft 27 which through a universal coupling 28 is connected with an outer feed shaft 29 on which the outer feed cup 4 is fixed, and is moved in one-way step-by-step motion in the direction of arrow B.

Evidently, the train of the above mentioned gears 21, 23, 24 and 26, can be substituted by similar driving means, such as, for instance, pulleys connected by belts or by lever system, and adapted for transmitting the motion from the inner feed cup 3 to the outer feed cup 4.

A novel feature of the present invention resides in the means for driving rollers 30 and 31 of the auxiliary feeding device. Said means comprises an intermediate gear 32 meshing with the gear 24 and driving another gear 33 keyed upon an inner vertical shaft 34 which extends downwards, which has a collar 30 secured thereto, which is integrally secured to said roller 30 by a set screw 35.

Likewise, an intermediate gear 36, which is keyed upon a spindle 37, meshes at one point of its periphery with the gear 26 and at another peripheral point with a gear 38 which is keyed upon an outer vertical shaft 39 which extends downwards and which has a collar 31 secured thereto, which is integrally connected to the roller 31 by a set screw 40. According to the aforedescribed arranged, the roller 30 rotates stepwise unidirectionally in the direction of the arrow A, in synchronism with the rotation of the inner feed cup 3, whilst the roller 31 rotates likewise in the direction of the arrow B in synchronism with the outer feed cup 4.

The two gears 32 and 33 are rotatably mounted on the rocking lever 41 which is pivotally mounted on spindle 25, said lever being normally urged in one rotative direction about said spindle by spring 43 which is interposed between lever 41 and a bushing 43'. Integral with lever 41 is a bushing 44 which surrounds shaft 34 and to which is attached a radially extending handle 42 which extends outwardly through an elongated opening 45 in the overhanging arm 2 of the machine. The machine operator can grip handle 42 and shift lever 41 about spindle 25 against the urging of spring 43 in a direction whereby inner roller 30 moves away from outer roller 31 whose axis is not shiftable.

The operation of the device is as follows: a portion of chainstitch 46 at the beginning of the seam is inserted between the rollers 30 and 31 after shifting said rollers away from each other by means of the handle 42, afterwards the outer feed cup 4 is shifted away from the inner feed cup 3 by a control (not shown in the drawings) acting on the universal coupling 28, and the work edges 47 to be sewn are inserted between the feed cups. According to the foregoing, the shifting of the cups away from each other is independent of the shifting of the rollers away from each other. The work fabric being sewn is fed by the feed cups 3 and 4 and passes through the rollers 30 and 31, which, in conformity with the thickness of the work fabric, shift more or less away from each other, against the bias of the spring 43. As subsequent parts 48 of work fabric to be sewn are inserted between the cups, they are held together 'by portions of chain-stitch 49, which, when the work is finished, are cut off from the sewn parts.

In this way, continuous uninterrupted operation is possible with the elimination of lost time which heretofore has been unavoidable since the machine had to be stopped at the termination of a seam on a work fabric.

The rollers 30 and 31 can be easily interchanged with others of different diameter and knurl pattern to suit different thicknesses of work fabric. In fact, it is possible in this way to vary the surface speed of the rollers relative to that of the cups in order to preclude elongation or stretching of the work fabric. Removal and securement of the rollers relative to their shafts is effected by means of the set screws 35 and 40.

The axes of shafts 34 and 39 are so positioned that, for whatever diameter rollers used, the rollers are properly spaced from cups 3 and 4. The rollers, regardless of their diameters, are always maintained in contact with each other because of the urging of spring 43 against lever 41.

I claim:

1. A sewing machine comprising elements for sewing stitches in a work fabric and a feeding means for feeding such a fabric past said elements, said elements and feeding means defining a path along which a fabric travels while being sewn by said elements, said feeding means including a pair of cooperating rotary feed cups and a pair of cooperating rotary rollers arranged successively along said path whereby a work fabric may pass first between said cups and then between said rollers as it travels along said path, means to drive said cups in opposite directions relative to each other in stepwise rotative fashion and means to drive said rollers in opposite directions relative to each other and in stepwise rotative fashion in synchronism with said cups.

2. The machine of claim 1, wherein both said rollers are positively driven.

3. The machine of claim 1, including an overhanging arm which overhangs said cups and rollers, said rollers being mounted on respective shafts which are mounted in said arm, a drive train extending from said cups into said arm and to said shafts.

4. The machine of claim 3, wherein said cups drive means comprises a power source arranged to drive a one of said cups rotatively in stepwise fashion in one direction, said drive train extending from said one cup into said arm and then to the other of said cups as well as to both of said rollers whereby the movement of said one cup is transmitted to the other cup but reversed as to rotative direction and the movements of said rollers are respectively synchronized with respective ones of said cups and respectively correlated therewith as to rotative direction.

5. The machine of claim 3, a one of said roller shafts being rotatably mounted about a fixed axis and the other of said roller shafts being mounted about a rotational axis which may be displaced relative to the axis of the one shaft whereby said rollers may be spread apart from each other, a yieldable means urging said other shaft in a direction towards said one shaft.

6. The machine of claim 5, said other roller shaft being mounted on a pivoted lever arm.

7. The machine of claim 5, including a hand control means connected to said other of said shafts and extending outwardly of said overhanging arm whereby the machine operator may spread said rollers apart.

8. The machine of claim 5, said rollers being removably mounted on said shafts whereby rollers of different diameters may be substituted for each other 011 said shafts.

References Cited UNITED STATES PATENTS 2,618,230 11/1952 Pons 112-18 2,962,988 12/1960 Pons 11218 X MERVIN STEIN, Primary Examiner GEORGE V. LARKIN, Assistant Examiner

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