IMPROVEMENTS IN PROCESSES AND APPARATUS FOR TRIMMING AND STITCHING FABRICS
Year: 1884

page_text: WC, JOHN WINFIELD DEWEES of Philadelphia, in the county of Philadelphia
and State of Pennsylvania, one of the United States of America, machinist, and
EDWARD BLACKFAN MOORE, of West Chester in the county of Chester, in said
State, printer, do hereby declare the nature of our invention for IMPROVEMENTS IN
PROCESSES AND APPARATUS FOR TRIMMING AND STITCHING FABRICS and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the accompanying
drawings in which fig. 1 is a front elevation partly broken away of machine
embodying our improvements, fig. 2 is a plan of cloth plate showing section of
trimmer, figs. 3, 4 and 5 are details.
Our invention has relation to fabric trimming devices and specially to such.
devices forming attachments to sewing machines.
Our invention has for its object to provide an improved construction of
mechanism whereby fabric may be trimmed by the action of two rocking jaws
operating to effect the separation of material fed between them, such separation
resulting from the pressure or abrasion of the jaws.
Our invention consists in the new process of trimming and stitching fabrics and
in the peculiar construction and novel combinations of parts hereinafter fully
described and specifically claimed.
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I
In the accompanying drawings we have shown our trimming apparatus as
forming an attachment to or as connected with a double-thread, lock-stitch sewing
machine, but do not confine our invention to this particular machine, inasmuch,
with slight modifications, within the spirit of what we have invented, our improve-
ments may be applied to or practised on other forms of sewing machines, or the
trimming effected apart from a sewing machine. Referring to the said drawings
A indicates the bed-piece of the machine, which is preferably made integral with.
the needle-arm B and head C. D represents the main-shaft, from which motion is
communicated both to the needle-bar E and to the feed-bar F; to the former by
means of a connecting rod (not shown) and to the latter by an eccentric b, which
gives the lifting motion, and by means of a connecting rod b', rock-shaft b² and
lever b³, which communicate the to-and-fro motion. G is the cloth-plate of the
machine having a transverse slot H for the Feed-dog H. This slot is made some-
what wider than the feed-bar so as to leave space for the trimmer. I is a bracket,
consisting of a plate I rigidly secured to or formed integral with a stock or
י

page_text: block 12. Said stock has lateral extensions with slots i¹ through which pass screws
that enter threaded openings in the bed-piece A, so that said stock is laterally
adjustably thereon towards and from the feed-bar. The upper end of the bracket I
is fastened by means of a screw to the head of the machine. On this bracket
are mounted two pivoted jaws or toggle levers, K and L respectively. The jaw K
is fulcrumed at k on the plate I' and is provided with a screw k¹ which passes
through a segmental slot 2 in the plate I. Said screw has a wide head ³, and
this prevents the jaw K from being sprung away from the plate I¹ or out of
alignment with the jaw L. Said jaw K has a tooth which enters a notch 1 in
the upper edge of the jaw L, so that when a rocking motion is communicated
to one jaw the other jaw will rock with it.
"
The adjacent edges of both the jaws are segmental or curved as shown. The
edge of jaw K is beveled or rounded or made blunt, or relatively so as compared
with what is called a sharp" edge, while the edge of the jaw L is decidedly
blunt, forming a shoulder or bearing for the edge of the jaw K, so that when
the jaws are rocked their pressure against or towards each other will effect a
rending or rupturing, as distinguished from the cutting or shearing, of the fabric
fed between them. To facilitate the feed of the fabric between the jaws, the jaw L
has teeth on one side of its edge as shown. The jaw L occupies a kerf or slit m
in the center of the stock 12 and is fulcrumed in said stock in the following described
manner Said stock is formed with a lateral opening N whose vertical depth is
greater than its width. In this opening are two boxes OO having flat vertical
sides and central cylindrical openings. These boxes form bearings for the trunnions
of the jaw L. Said trunnions are composed of a screw P which fits in a threaded
opening near the lower end of jaw L and projects equally on both sides of said jaw.
On this screw are threaded sleeves pp having shouldered heads p¹ p¹. To fit these
The screw P is
parts together the jaw L is first passed down into the kerf m.
then inserted in the opening provided for it in the jaw L, passing through the
boxes OO. The sleeves pp are then turned on to the screw P, passing into and
filling up the openings in the boxes 0 0.
Now, when the jaw L rocks the screw P and its sleeves pp together oscillate in
the boxes O O. To communicate a rocking motion to jaw L it is pivotally connected
at 1 to a connecting rod L' whose other end is pivotally attached to a rock-arm b
on the shaft b'. To secure a vertical adjustment of the jaw L to take up lost
motion, or to bring the edges of the jaws closer together, or to separate them, the
boxes rest upon pins qq fitted in vertical openings in the stock I³ and resting upon
a wedge-shaped or beveled slide R supported upon pins or ways rr which extend
transversely of a slot in the bottom of the stock 12 in which the said slide R is
fitted. S is an adjusting screw secured at its inner end in the wedge or slide R
and provided with a nut s. By turning this nut the slide R will be drawn length-
wise and, according to the direction of its motion, cause the pins qq to rise or to
fall-thereby lifting or lowering the boxes OO and adjusting the jaw L relatively
to jaw K. The screw P may be made with only one detachable sleeve and have
a smooth neck and a head integral with its body as shown in fig. 4.
The operation is as follows: Fabric to be stitched and trimmed is fed to the
machine in such a way that the edge to be trimmed will pass between the edges of
the jaws K L. As the stitching is formed in the fabric the jaws rock and bite off
the superfluous edge of the fabric, the removed portion passing away through
a flaring opening L³ in the plate 11.
Having now particularly described and ascertained the nature of our invention
and in what the same is to be performed, we declare that what we claim is
1. The process herein described for trimming fabric consisting in removing a
superfluous edge or part by pressure or abrasion producing a rendiing or rupturing
of the fabric, substantially as set forth.
2. The process herein described of stitching and trimming fabric consisting in
stitching the same and simultaneously therewith removing a superfluous edge or

page_text: part by the pressure or abrasion of devices which rupture or rend such fabric,
substantially as set forth.
3. In combination with the bed-piece and head of a sewing machine a bracket
or support for the jaws of a trimming attachment, said bracket or support being
secured to both said bed-piece and head substantially as shown and described.
4. The combination with the bracket or support I, having slot k', of jaw K
fulcrumed thereon and provided with headed screw k², substantially as shown and
for the purpose set forthi.
5. In a fabric trimmer comprising two jaws, a jaw L having feeding teeth on one
side of its edge substantially as shown and described.
6. In a fabric trimmer comprising two levers or jaws fulcrumed on a bracket or
support, the combination with the adjustable lower jaw, having trunnions which
fit in vertically movable boxes, of a sliding wedge or bevelled block R, substantially
as shown and described.
7. The combination with bracket or support I comprising plate I¹ and stock I³,
of jaws K and L, vertically adjustable boxes 00 screw P, sleeves p, p, pins q q
slide or wedge R supporting pins adjusting screw S and nut 8 said several
parts being constructed and arranged for operation substantially as shown and
described and for the purpose set forth.