US272805A - And john h - Google Patents

Description

(No Model.)

A. E. WALLACE 8v J. H. GRIFFIN.

TRIVMMING ATTACHMENT FOR SEWING MACHINES. A No. 272,80 Patented Feb.20, 13.

Wv'bmeoses:

N. PETERS. Phoxn-umugraphar. wnahingm", D. C.

UNITED STATES ALBERT E. IVALLACE, OF HARTFORD, CONNECTICUT, AND JOHN H. GRIFFIN,

OF BROCKTON, MASSACHUSETTS;

SAID WALLACE ASSIGNOR TO SAID GRIFFIN; SAID GRIFFIN ASSIGNOR OF ONEHALF TO CHARLES CURTIS,

OF BOSTON, MASSACHUSETTS.

TRINIMING ATTACHMENT FOR SEWING-MACHINES.

SPECIFICATION forming` part of Letters Patent No. 272,805, dated February 20,` 1883.

Application filed November 25, 18852. (No model.)

To all whom it may concern Beit known that we, ALBERT E. WALLACE, of Hartford, countyr of Hartford, and State of Connecticut, and JOHN H. GRlFFIN, of Brockton, in the county of Plymouth and State of Massachusetts, have invented certain Improvements in Trimming Attachments for Sewing- Machines, of which' the following is a specilication.

1o This invention has for its object to provide a simple and ecient trimmer attachment for a sewing-machine, adapted to be attached entirely to the head of the machine without interference with any ofthe working` parts, and having a trimming-knife which is moved diagonally down ward-in makingits cut,and is adapted to have thelength ofits cutregulated,to be moved independently by the operator when a cut of extra length is to be made, and to be zo raised independently from the bed of the machine to any desired height, and at the same time be made inoperative.

To these ends our invention consists in the improvements which we will now proceed to` .3o 2 and 3 represent respectively side and top views of the same. Fig. 4 represents an kelevation of the rear side of the lower portion of head, and Fig. 5 represents an improved form of trimming-knife.

The same letters of reference indicate the -same parts in all the gures.

In the drawings, A represents the head of a sewing-machine; B, the presser-bar; C, the. needle-bar, and D the oscillating shaft, which 4o operates the needlebar in the usual manner.

In carrying out our invention we apply to one side of the head A, by means of screws a a, a bracket, b, having in its lower portion diagonal gnidesc c, extendingdownwardly` and inwardlyl toward the needleplate t.

said guides is fitted to slide freely a plate, e, to the lower end of which is detachably secured by meansof ascrew, h, atrimming-knife,

Between j'. having a substantially vertical cutting-edge, f', projecting at its lower end, when the knife 5o is in its normal position, into a slot in the needle-plate t, beside the needle-hole. The plate e is normally raised by a retractingspring, t7, which is attached at one end to a stud,j, projecting from the rear side of the plate e through a slot in the bracket-vb, and at the other end to said bracket.

k represents a rock-shaft journaled in a sleeve formed on the bracket' b, and provided With a cam, l. bearingon the upperend of the 6o plate e, and supporting the latter against the upward pressure of its spring t'. The opposite end ofthe rock-shaft k is provided with an arm or lever, m.

nrepresents a connecting rod or link pivoted to the lever m and to a pin or stud, o, on a collar, p, which is rigidly attached to the oscillating shaft D. The oscillationsofthe shaft D are communicated to the rock-shaft le by the link n and lever m, and the plate e, with its 7c knife, is alternately depressed by the downward movements of the cam l and raised by the spring fi. The knife is thus reciprocated and caused to trim the work while it is being stitchetLandinalineparallel with the stitches. The diagonal position of the guides cc and their arrangement with relation to the needle and needle plate cause the knife to move diagonally downward while cnttingthe material; hence the knife, while avoidinga direct downfy 8o ward chop or cut, has a downward movement snfcient to enable its cutting-edge to press downwardly on the upper surface of the material while cutting, and thereby, insure a smooth and compact trimmed edge without the necessity of holding or clamping the material between the needle-plate and a fixed or non-rotating presser-foot located close to the point where the knife cuts; hence the cut can be made at any desired distance from the edge 9o of the presser-foot, and a roll-presser can be employed equally as well asanonrotating one.

1t will be observed that the attachment is adapted to be very readily applied,no adapta.` tion of the machine being required excepting the formation of holes in the head for the CAO vof the cutting-blade.

screws a a; and the application of the collar p to the shaft D. rlhe plate e has a knob or handle, e', which enables the operator to depress the plate and knife independently, and thus cause. the knife to make a cut of greater lengthvthan usual and trim in advance ofthe line of stitching. This operation is performed when the stitching makes an abrupt angle and it is desired to trim the edge parallel therewith, the knife being depressed before the work is turned to change the direction of the line of stitches. The rock-shaft 7o is longitudinally movable in its supporting-sleeve, so that it can be displaced to remove the cam Z from the plate c, thus making the latter inoperative and permitting it to be raised above the needle-plate by its retraeting-spring far enough to prevent the knife from interfering with the work. The degree of this upward movement may be regulated by an adjustable stop, u, on the rear side of the bracket b, said stop being adapted to arrest the studj of the plate e. A spring, fu, interposed between the cam Zand the end of a socket formed in the supporting-sleeve, normally holds the cam in position over the end of the plate e. The arm m is adjustable in length, so as to enable the rocking movement of the rock-shaft.. and the consequent depression of the plate e and its knife to be varied. This adjustability is effected by making the arm m free to move endwise in the rock shaft, providingit with anut, w, on its threaded outer end, and interposing a spring, fr, between its other end and the rock-shaft, said spring holding the nutw with a yielding pressure against the rock-shaft. By rotating the nut the distance between the rock-shaft and the end of the lever m, to which the rod n is pivoted,-is shortened orlengt-hened, as the case may be. The length of stroke or out of the knife is thus enabled to be readily shortened when trimming re-entrant curves. For trimming abrupt curves and scalloped edges, we prefer to employ a knife having a notch or recess, z, in its back, as shown in Fig. 5, said notch receiving the material, as represented by the dotted lines in said ligure. One side of said notch is substantially parallel with the cntting-edgef, and forms the back l This form ot' blade euables the work to be turned with equal facility on the cutting-edge, whether the knife is at the upper or lower end of its movement, whereas, if thecutting-edge and back were not parallel, the blade would present a different width at the lever of the work-support. when at the lower end of its movement from that presented when at the Lipper end of its movement, and more difculy would be experienced in turning the work around the wider portion ofthe blade than around'thenarrowcr portion.

We claim- 1. In a sewing-machine, a bracket having anism supported by the head of the machine for reciprocating the slide in said guides, whereby the knife is given a diagonally-downward movement when cutting the work, as set forth.

2. rEhe combination, with asewing-maehine. 0f a bracket having diagonal guides, attached to the head of the machine., a plate adapted to slide in said guides and provided with a knife projecting into a slot in the needle-plate, a spring to normally raise and retract said plate and knife, and a rock-shaft oscillated by a connection with the needle-bar-operating shaft and provided with a cam bearing on the knifeholding plate, as set forth.

3. The combination, with a sewing-machine, of a bracket having diagonal guides, attached to the head of the machine, a knifeholding plate adapted to slide in said guides and provided with a knob or handle, and a retractingspring normally pressing the plate upwardly against a depre singvdevice and permitting said plate to he depressed by the operator independently of said depressing device to make a cut of extra length in the material, as set forth.

4. The combination, with the spring-retracted diagonally-movable knife-carrying plate, ot' a device for depressing said plate against the force of its spring, said device heilig capable of displacement to make the knife inoperative and permit the spring to raise the knife above the bed of the machine, as set forth.

5. The combination, with the spring-retracted diagonally-movable knife-plate, ofthelongitudinally-movable rock-shaft, operated as described, and having a caln which bears on said plate when the rock-shaft is in its normal position, and aspring to hohl the rock-shaft and its cam in their normal position, as set forth.

6. The combination, with the spring-retracted knife-holding plate, of an adjustable stop to limit the upward movement imparted to the knife and plate by the retracting-spring, as set forth.

7. The combinatiomwith the spring-retracted knife-holding plate, of the rockingl cam, adapted to intermittently depress said plate, and adjustable mechanism for varying the length of the rocking movement of the cam, whereby the length of cut made by the knife may be regulated. as set forth.

8. The combination, with the spring-retracted knife-holding plate, of `the rock-shaft havfing the plate-depressing cam, and the adjustable arm, connected by a link to the needlebar-operating shaft, the adj ustability of said arm enabling the length ot'movement imparted to the knife to be regulated, as set forth.

9. The improved trim ming-knife, adapted to move diagonally, and formed with a notched or recessed back having a substantially vertical side, forming the back of the blade, and a cutting-edge, f', substantially parallel with the back, said notch or recess forming an unob.- structed space at the rear of the cutting-edge,

IOO

IIO

IZO

while the parallelism of the cutting-edge and two subscribing witnesses, this 22d day of N othe back-of the blade enable the Work to be vember, 1882.

turned on the edge :md in said space with ALBERT E. WALLACE. equal facility whether the knife is at the up- JOHN H. GRIFFIN. 5 per or lower end of its movement, asset forth. l Witnesses:

l In testimony whereof We have signed our A. P. HYDE,

, names to this specification, in the presence of I FRANK E. HYDE.

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