G. C. BISHGP.
Patented March 3. i874.
UNITED STATES PATENT OFFICE.
GEORGE C. BISHOP, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO ALFRED B. BEERS, OF SAME PLACE.
Specication forming part of Letters Patent No. 148,024, dated March 3, 1874; application led- January 21, 1874.
To all whom it may concern:
Be it known that I, GEORGE C. Bisi-Tor, of Bridgeport, in the county of Fairfield and State of Connecticut, have invented a new and useful Improvement in Shuttle Sewing- Machines; and I do 4hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings making part of this specilication, in whichy Figure lis a perspective view of an ordinary shuttle-thread or Howe sewing-machine, with my improvement applied to it, a part of the bed-plate and of the capping of the box portion of the standard of the needle-arm being broken away in order to show my improvement more clearly. The adj listing-screw of the shuttle-thread tension device is also removed. Fig. 2 is a vertical lsection through the capping-plate of the box portion of needle-arm standard, showing the tension adj Listing-screw, which was removed in Fig. l. This view also shows the tension-lever and end of spring. Fig. 3 is a view of the inner side ofthe capping-plate of the box portion of the needlearm standard, showing the tension-lever pivotcd to it, and the cone end of the adjustingscrew. Fig. 4 is a perspective view of a portion of the machine and improvement, showi-ng the shuttle-thread relieved from tension. Figs. 5 and 6 are views of the device which grips the thread to produce tension upon it. Fig. 7 shows the griping end of the griping device, with a lip on its under edge instead of with a V-groove in its end.
My invention has reference to the shuttlethread sewing-machine, in contradistinction to those machines which are constructed with revolvingorturninghooks,orrevolvingthreadcarriers. The nature of my invention consists, iirst, in a tension griping-lever, having its fulcrum in the shuttle-race, and made to bite against the side wall of the raceway upon the shuttle-thread, and operated directly by the shuttle-driver. Second, in a shuttle sewing-machine,the combination of the spring tension-lever, constructed and arranged as described, the shuttle-driver constructed asdescribed, and the intermediate releasing-spring connectingrod. Third, the griping-jaw formed on the tension-lever, with a groove or ledge, to prevent the thread getting loose while the machine is in operation. Fourth, in the combination of the vibrating tension regulating-lever, the sideimpinging conical tension-screw, the spring connecting-rod, and the griping tension-lever, whereby the very nicest adjustment may be obtained. Fifth, in the combination of a regulated spring-griping tension-lever, having its fulcrum in the shuttle-race, with a shuttle carrier or driver, which actuates the said lever directly. This invention produces the most perfect tension at `the time required, and yet leaves the cloth free to be moved when the tension is not required, the thread being kept tight while the stitch is being completed and immediately slackened on the completion of the same, orthe moment the shuttle begins its return or back movement.
A is the needle-bar of the machine 5; B, the feed-plate. On that side of the raceway next to the feed-plate, the stitching-plate C is eX- tended at right angles forward and downward, as at C'. This extension forms a stationary gripingjaw. In rear of this jaw another gripingjaw, D', of an angular lever, D, is located so as to stand just a little higher than the top of the shuttle E, and a little lower than the plate C, as shown. The griping-jaw D is grooved or ledged, as at c, so as to prevent the thread descending after it has taken hold of it. The lever of the jaw is depressed and narrowed so as to be slightly yielding along a portion of its length, and is pivoted near the edge of the table, as at b. The depressed portion of the lever has a wedging form on its rear edge, as at c, and beyond this wedgeshaped portion a stop, d, is provided on the lever. On the shuttle-carrier an extension, f, is made, and from the top of this extension a friction-pin, g, projects so as to strike the Wedge-shaped portion of the lever after the shuttle has been carried forward the proper distance. The contact of this pin with the lever causes the jaw D' to approach the jaw C', and, as the thread between the shuttle and the cloth is in the path of the movement of the jaw D', this thread is carried along by `the jaw D', and finally griped firmly between jaws D' and C', and held so until the needle has tightened the stitch 'upon the cloth. The1 back-movement ot' the shuttle-carrier releases the lever by withdrawing the pin oi' the wedge. To effect the retreat of the jaw D' from the jaw C' from the position shown in Fig. l to the position shown in Fig. 4, a spring connecting-rod, E, is fastened to the lever at its angle, and to place the lever D and its jaw, D', under control, so that the degree of tension may be regulated, this spring-rodl is fastened to a vibrating lever, F, which is pivoted to the capping-plate G of the box portion of the needle-arm standard H, as shown. The upper end of this lever, F, is slightly deflected from a vertical plane, and this deiiected portion is curved or concaved, as at h. For producin g or regulating the tension,a conic pointed screw-pin, l, is passed through a box-nut, J, of the plate G, so that its cone point passes by the concave part of the lever, and the conic surface back of the point iinpinges upon the said concave endof the lever, as shown in Figs. 2 and 3 ot' the drawings. By means of the screw the spiral or helically-wound portion of the spring-rod E can be extended so as to increase the tension, or allowed to shorten so as to decrease the tension upon the thread.-
The operation is as follows: As the shuttle advances through the loop of the needle, the shuttle-carrier pin comes in contact with the spring tension-lever and forces it against the extension of the stitching plate. As the lever moves toward the plate, its grooved or lipped jaw carries the lower or shuttle thread to the j aw C and grips it fast between itself and the said jaw, and thereby prevents its further passage at the moment the needle is being drawn up. The stitch being fastened, the
shuttle and the griping-j aw are drawn back by the spring tension-rod, and thereby releasel their hold upon the thread, allowing the shuttle-thread to run free.
I do not claim an independent tension outside of the shuttle of a shuttle sewing-machine, broadly; but
l. In a shuttlesewing-machine, the tension griping-lever D D', constructed substantially as described, and having its fulcruni in the shuttle-race and Inadeto bite against the side wall of the raceway upon the shuttle-thread, and operated directly by the shuttle-driver, substantially as described. 2. The spring griping tension-lever D D', constructed and arranged as described, the
shuttle-driver with its pin g, and the releasing spring connecting-rod E, substantially as and for the purpose described.
3. rEhe spring griping tension-lever D D', with the groove or ledge a in its jaw, D', as and for the purpose described.
4. The side-impin gingregulatin g cone-screw, in combination with the laterally-deected vibrating lever F h, spring connecting-rod E, and the spring griping tension-lever D D', substantially as and for the purpose described.
5. The griping-lever, arranged in the shuttlc-race and operated by the shuttle-driver to gripe the shuttle-thread against the race, in combination with mechanism, substantially as described, for regulating the pressure of the lever, as set forth.
GEORGE C. BISHOP.
Witnesses H. H. BISHOP, A. B. Banus.