US117262A - Improvement in sewing-machines - Google Patents

Description

PATENm JUL 251871 Witnesses UNITED STATES` PATENT OFFICE.

THOMAS CRANE, OF FORT ATKINSON, WISCONSIN, ASSIGNOR- TO HIMSELF' AND MELVIN A. JONES, OF SAME PLACE.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming p'art of Letters Patent No. 117,262, dated July 25, 1871.

To all whom it may concern:

Be it known that I, THOMAS CRANE, of Fort Atkinson, in the county of J eii'erson and State of Wisconsin, have invented a ne'w and useful Improvement in Sewing-Machines; and I do hereby declare the following to be a full, clear, and exact description thereof, which will enable others skilled in the art to which my invention appertains to make and use the same, reference being had to the accompanying drawing forming part f this specification, in which- Figure l is a side elevation ot my invention with a part of the frame broken olf, cutting a portion of the moving-part through the center. Fig. 2 is an end view of a portion of the Vsame detached therefrom. Fig. 3 is a vertical transverse section through the presser-bar, showing the moving parts thereof. Fig. 4 is an end view of the cam-wheel employed in giving motion to the moving parts of the machine. Fig. 5 is a cross-section of the same, showing the stirrup and rock-shaft employed in oscillating the shuttle-bar. Fig. 6 is a-.side view of the same with the stirrup removed, showing the camgroove by which the oscillating movement of the shuttlebar is produced; and Fig. 7 is a top view of the shuttle enlarged, showing the manner of adjusting the springby which the proper tension of thread is obtained. Y

Similar letters of reference indicate corresponding parts in the several figures of the drawing.

The object of my invention is to provide a sewing-machine. the mechanical parts of which are so arranged as to simplify the general construction and operation of the same, and so that it will sew backward or forward7 at the will of the operator, without readjustment or change of stitch. The improvement consists, among other things, in securing a crank-shaft, operating the needle-bar, to and within a tubular oscillatory bar so arranged as to vibrate laterally simultaneously with the rotating movement of the shaft, by which means the crank is uniformly at a center vertically with the needle-bar, thus imparting to the same a positive vertical movement. It further consists in providing' the wheel or pulley ofthe crank-shaft with a cycloid cam-groove, within which is fitted a semi-angular oscillating stirrup, to which is pivoted a rock-shaft communicating with the shuttle-bar, by which means a reciprocal movement is imparted to said shuttle-bar by the combined vibrating movement of the crank-shaft and oscillating movement of the stirrup produced by the rotary movement of the cam, thus moving the shuttle alternately with the needle by which the stitch is formed.

In the accompanying drawing, A represents the frame of the machine, which may be as shown, or of any known form that will receive the moving parts, and is secured to the table-top in the usual manner. B is a vertical guide-spindle, which is firmly affixed to the forward end of the frame. C is a tubular needle-bar, which is fitted upon said spindle in a manner admitting' of a free and easy vertical movement. The lower end of said needle-bar is provided with an aperture, into which the shank of the needle a is introduced, which is rmly secured therein by a set-screw, b, passing through the side of the bar. I construct the lower portion of said bar solid between the shank of the needle and the lower end of the guide-spindle, thusadmitting the introduction of oil into said bar without the liability of its dripping upon the fabric. D is a tubular triangular bar, which is pivoted at its upper and lower end to the frame of the machine in a manner securing the same rigid vertically, but so arranged as to admit of an easy lateral reciprocal movement. E is the shaft giving motion to the neeclle-bar,v'l1ich is loosely fitted within said bar D, and so arranged as to rotate therein. The forward end of said shaft is made less in diameter, and is bent or slightly curved sufficient to form an eccentric or crank, the end of which is provided with an aperture or socket, into which is loosely fitted a pivot, d, affixed to the upper end ofthe needle-bar. Firmly secured upon the rear end of said shaft is a sleeve, F, upon which is loosely fitted a pulley, G, which is provided externally with an annular groove, c, that receives the belt from the driving-wheel, not shown in the drawing. I provide the inner end of said sleeve with a ange, a portion of which is cut away, forming a clutch which is loosely itted within a corresponding recess, g, cut on the inner end of pulley G. Said recess is provided with a stop-clutch, h, so arranged as to allow the pulley to rotate partially around upon said sleeve, the object of which is to reverse the entire moving parts of the machine, thus allowing the fabric to be stitched in abackward direction and preserving the corresponding stitch. I provide pulley G with an annular cycloid cam-groove, H, within which is loosely fitted a semi-annular stirrup, I. To the upper end of said stirrup is pivoted externally a like stirrup, J, the lower portion of which is firmly afxed to the upper end of a vertical rock-shaft, K, and is so arranged as to allow said stirrup I a slight oscillating movement therein. The lower end of said shaft K is firmly aflixed to the rear end of the shuttle-bar L, and is secured within an outward-projectin g portion of the lower end of bar D, and is so arranged as to admit of a slight reciprocal rotary movement. Thus, as said pulley G is rotated, together with the oscillating movement of bar D produced by the rotating movement of shaft E, a reciprocal movement is imparted to the shuttle-bar. M is the feed-bar, which is pivoted at its forward end to the lower side of the platform, and its rear'en d loosely litted upon the lower end of lever N. The upper end of said lever is pivoted eccentrically to shaft E, and is provided at its lower end with a screwthreaded nut, upon which the end of said feedbar is supported, thus allowing said bar to be raised or lowered, by which the feed is adjusted for thick or thin fabric. Upon the lower end of said lever, and around the same above the feedbar, is a spiral spring, m, so arranged as to rest uponv its end, by which the same is secured in proper adjustment. Loosely fitted upon said lever is a sleeve, O, which is secured within a vertical slot or mortise in the end of the frame, and is so arranged as to admit of a slight rocking movement, thus forming the fulcrum of said lever, by which an elliptical reciprocal movement is imparted to the feed-bar by the rotating movement of shaft E. Said sleeve is so fitted within the slot as to admit of being secured at and proper adjusted height, thus increasing or diminishing the stroke ofthe feed-bar, by which mea-ns the graduated length of stitch is obtained. I) is the take-up bar, which is loosely pivoted to the end of the frame, and Q the take-up spring, firmly affixed thereto. P is an adjustable tubular guide-bar, which is fitted within a pivot affixed to the frame. The thread from the spool is passed around and through said bar, thence upward through the end of bar l and over the end of spring Q, thence downward in a stra-ight line to the needle, the object of which is to secure the proper tension of the thread without lateral friction of the same. It is a tubular presser-bar, which is firmly secured to the frame by a screw-threaded bolt, n, passing into the upper end of the same. The lower end of said bar is provided with a -vertical groove, within which is iitted the shank of the presser-foot S. Aftixed to the upper end of said shank is a vertical spindle, p, around which is ysecured a spiral spring, fr, by which the proper pressure is obtained upon the fabric. Firm 1y attached to the shank of said presser-foot is a set-screw, t, which is so arranged as to move freely within a vertical slot, s, cut in the lower end of said bar. The upper end of said slot is provided with a recess, into which the head of said screw is admitted, said shank being so ar 1anged as to admit of a slight vibrating movement to allow the same, by which means said presser-foot is secured from and above the fabric. I provide the shuttle T with a curved spring, U, one end. of which is rmly affixed thereto. To the opposite or curved end of said spring is attached a lug, t, within which is secured a set-screw, W, so arranged as to come in contact with and against the inner side of the shuttle. The upper edge of said spring is provided at or near its center with a groove or slot cut across the same, through which the thread from the bobbin passes, the thread passing thence downward by the side of said spring and through an aperture in the side of the shuttle; thus, as said screw is adjusted, the spring is pressed against the thread, by which means the proper tension is obtained.

In operating my invention, power is applied to the treadle, which is communicated to pulley G of shaft E in the usual manner, giving to said shaft a rotating movement, by which all the moving parts of the machine are made to perform their necessary function.

Having thus described the nature and object of my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. A sewing-mechanism, composed of an eyepointed needle receiving its motion from a crank coupled directly to the needle-bar, a self-adjusting cam-pulley upon the crank-shaft, and an oscillating bar carrying the crank-shaft, substantially as described, the combined action of which governs the feed, shuttle, and needle movements, in sewing the same form of stitch forward and backward, by reversing the motion ofthe machine, substantially as specified.

2. The crank-shaft E, when so arranged as to vibrate laterally simultaneously with a rotary movement of the same, whereby a vertical movement is imparted to the needle-bar, substantially as described.

3. The combination of the crank-shaft E, vibrating' bar D, cam-pulley G, and rock-shaft K, the whole arranged to operate together, whereby a reciprocal movement is imparted to the shuttle-bar, substantially as described.

4. The combination of pulley Gr, stirrups I and J, rock-shaft K, oscillating bar D, and shuttlebar L, theI whole arranged to operate together, whereby the requisite reciprocating movement is imparted to said shuttle-bar by the rocking movement of the shaft K jointly with the oscillating movement of bar D, substantially as and for the purpose described.

The above specification of my invention signed by me this 23d day of November, 1870.

THOMAS CRANE.

Vitnesses:

G. H. FRos'r, N. H. SnERBURNE.

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