US705633A - Feed mechanism for sewing-machines. - Google Patents

Description

Patented July 29, |902.

J. A. ATcHELoR s. F. E. HALL. FEED WIEGHANISNI` FDR SEWING MACHINES.

(Applitin led Dec. 16, 1899.)

(No Model.)

LUNiTn o STATES PATENT OFFICE.

JOHN ARTHUR BATCHELOR ANDFRANCIS ERNEST HALL, OF LONDON,

` ENGLAND.

`FEED MECHANISNI FOR SEWING-MACHINES.

SPECIFICATION forming part 0f Letters Patent No. 705,633, dated July 29, 1902.

Application filed December 16, 1899. Serial No. 740,546. (No model.)

ism of sewing-machines, and more particularly to top-feed mechanism of machines having a frame and main driving-shaft arranged as shown in the specification of Bensons English Patent No. 5,903 of 1893. In these machines the presser-foot receives motion from two distinct sets of mechanism, one of which produces the forward motion and the other the down motion of the same, while the m0- tions in the opposite directions-viz., the backward and the up motion--are produced by'springs. The two sets of mechanism mentioned above are driven from a pair of singleacting cams, which turn on an axis parallel to the driving-shaft of the machine. With the naine single-acting cam we wish to designate a cam which acts on a friction-roller or analogous mechanism in one direction only-that is to say, which presses the same either toward the axis of the cam or away from the same, as thecase may be--while the motion of the friction-roller in the opposite direction (away from the axis of the cam or toward the same, as the case'may be) is produced by a spring, which always keeps the roller in contact with the cam. If such a machine works at a great speed, the cloth-feedV becomes unreliable and irregular, because the oscillating forward and backward motion of the presser-foot depends partly on a spring.

The present improvement has for its object to render such machines suitable for high speed byimparting to the presser-foot a positive forward and backward motion.

In the accompanying drawings, Figure l is a side view, andFig. 2 an end view, of a feed mechanism embodying our invention, while Fig. 3 shows a detail of construction.

The cloth-presser a, which shifts the cloth, is adapted to move both horizontally and vertically. The vertical motion is produced in `a helical spring n.

the usual manner by causing the cloth-presser to slide up and down in a vertical guide-piece b placed at the head of the machine, while the horizontalmotion is produced by the mechanism hereinafter described. Both motions are derived from a grooved disk or cam c, which is rigidly fixed to` a spur-wheel ol, set in motion from the main driving-shaft eby means of another spur-wheel f, commonly usedin machines of the Thomas and Benson type, and therefore only indicated by dotted lines. The lifting of the presser-foot is produced by the nose csof the small cam c', fixed to the face of the double-acting cam or grooved disk c, said nose os acting upon a friction-roller o, held in the extremity of a two-armed intermediate lever o, which has its fulcrum at p and is connected with the clOth-presser a by been thus lifted it is drawn down again by a helical 'spring q, attached at one end to the guide-piece l) by a hinge-pin and acting at the other end on the lever 0 by means of an adjustable screw-nut r. The horizontal motion of the presser-foot is produced by a speciallyshaped groove c2, formed in the circumference of the disk or cam c through the intermediary of a two-armed intermediate leverf, having atits lower end a friction-roller f and at its upper end a sliding blockfz, secured to the lever, a forked lever g, having a longitudinal slot g", in which slides the said block f2, a horizontal shaft h, which is supported by pivotal bearings `m and 'm2, projecting from the machine-frame m, and a lever t', adapted toV act on the cloth presser at by means of a sliding block rl, pivoted to the extremity of the lever t, and a vertical slot a2, formedin the cloth-presser a. The rear lever g andfront lever t are fixed to the shaft 71, and extend dowuwardfrom the same. The fulcrum of the lever j j is supported in a bracket m3, fixed to the frame fm.

Fig. 3 represents the circumference of the grooved disk c, laid out into a plane, so as to show the shape of the groove c2. As the groove has two lateral bends or deviations k, each revolution of the cam c will produce two forward and two backward motions of the cloth-presser d.

The eifectivc length of the lover f may be After the presser has regulated by varying; the position of the sliding block f2, which has a set-screw for securing it in the desired position, as shown by Fig. 2. As the stroke or the amplitude of oscillation of the lever g depends on the effective length of the lever f and the clothfeed depends on the length, of the stroke or oscillation of the presser-foot a in a horizontal direction, the cloth-feed may be regulated by varying the position ofthe sliding block f2 on the leverf. y

What we claim isl. In top-feed mechanism ofhigh-speed sewing-machines having a horizontal rear driving-shaft, a vertically and horizontally movable presser, a rocking shaft together with a cam-and-lever mechanism situated between the driving-shaft and the presser, the combination of the said driving-shaft with a vertically and horizontally movable presser, means for imparting to it a vertical motion, a grooved cam adapted to receive continuous rotary motion from the driving-shaft, a rocking shaft situated `between the presser and the driving-shaft and adapted to turn in bearings secured to the machine-frame, and adinstable lever mechanism adapted to transmit motion from the grooved cam to the rocking shaft and from the rocking shaft to the presser both forward and backward at an adju stable rate of transmission, without the aid of a spring, substantially as described andy for the purpose specified.

2. In top-feed mechanism of high-speed sewing-machines having a horizontal rear driving-shaft, a vertically and horizontally movable presser, a rocking shaft together with a cam-and-lever mechanism situated between the driving-shaft and the presser, the combination of the driving-shaft, rocking shaft and presser, with means for imparting to the presser a vertical motion, a grooved cam adapted to receive continuous rotary motion from the driving-shaft, a one-armed lever mounted on the rear end of the rocking shaft, a two-armed lever adapted to receive motion from the grooved cam at one end, and to transmit it to the said rear lever at the other end by means of an adjustable pin and a slot adapted to vary the rate of transmission, and a one-armed lever mounted on the front end of the rocking shaft and connected with the presser by means of` a pin and slot, adapted to produce the forward and backward motion of the same, substantially as described and for the purpose specified.

3. In top-feed mechanism of high-speed sewing-machines having a horizontal rear driving-shaft, a vertically and horizontally movable presser, and a rocking shaft together with cam-and-lever mechanism situated between the driving-shaft and the presser, the combination of the driving-shaft e, rocking shaft h and presser a, with means for imparting to the pressera vertical motion, a grooved cam c geared together with the driving-shaft, a slotted lever g mounted on the rear end of the rocking shaft, a lever f having on one arm a roller running in the groove of the cam o and on the other arm an adjustable block f 7o connected with the slotted lever g, and a lever 1l mounted on the front end of the rocking shaft h and connected with the presser by means of a pin t" and a slot a2, substantially as described and for the purpose specified.

In witnesswhereof we have hereunto set our hands in the presence of two subscribing,r witnesses.

JOHN ARTHUR BATCHELOR. FRANCIS ERNEST HALL.

Witnesses:

J. WETTER, GEO. BENSON.

Images