Improvements in Cloth Clamps for Button-hole Sewing
Year: 1886

page_text: Date of Application, 15th Apr., 1835.
Complete Left, 13th Jan., 1887.
Complete Accepted, 15th Feb., 1887.
[Communicated from abroad by THE SINGER MANUFACTURING COMPANY, of New York,
in the United States of America, Sewing Machine Manufacturers.]
Improvements in Cloth Clamps for Button-hole Sewing
1, ALEXANDER ANDERSON, Manager of the Singer Manufacturing Company's
Works, Kilbowie, Dumbartonshire, do hereby declare the nature of this invention to
be as follows :-
My invention relates to that class of work clamps adapted to open and spread the
bution-hole after the work has been clamped and it comprises certain improvements
on the clamp described in the Specification of Letters Patent No. 7508 dated June 19th
1885, the object of the present invention being to render my clamp more convenient.
for use.
Upon the base plate of the clamp lower clamping plates or jaws are fitted to slide
laterally, the lateral movements being effected by a slide having inclined ribs working
in inclined grooves in the lower surfaces of the plates. The upper clamping jaws
are carried by arms attached to plates hinged to blocks which are attached to and slide
laterally with the lower clamping plates. The upper jaws are forced down against the
lower clamping plates by a cross-bar connected by a link or pitman with a crank on a
small shaft having its bearings in the sliding block, said shaft being operated by a
clamping arm or lover attached thereto. All of the parts above-mentioned are, or
may be, the same as described in the Specification of the Patent herein before
referred to.
In this improved clamp the spreading lever is pivotted by a pin to a stationary
block attached to the base-plate, said lever being thus adapted to swing horizontally
and to move the spreading slide back and forth by means of a connecting link loosely
attached to said slide and lever. The clamping arm or lever is provided with a
projection which is arranged to come into the path of movement of a projection on

page_text: the spreading lever as the latter lever is moved inward to bring the clamping jaws
together prior to releasing the work when a button-hole has been finished. This
movement of the spreading lever will move the clamping lever from the vertical to
the horizontal position and the shaft to which the clamping lever is attached will be
turned far enough to throw the crank over the dead centre, and the arms and upper
clamping jaws will then be instantly lifted by springs placed between the sliding
blocks and the arms of the jaws, thereby fully releasing the work. Thus it will be
apparent that the work will be released by operating the spreading lever only.
In order that the clamping jaws may hold the material securely without requiring
too much force in clamping it has heretofore been customary to roughen their adjacent
surfaces to enable them to take a firm hold on the material, but this is objectionable
when working on finely finished leather and some other classes of work as the surfaces
of the material is more or less marred by the roughened surfaces of the clamping jaws.
To obviate this difficulty and still enable the clamping jaws to hold the work securely,
so that it will not slip when the bution-hole is being spread, I have provided the lower
clamping jaws with shallow concave grooves and the upper clamping jaws with convex
projections fitting said grooves. These grooves and projections are preferably slightly
removed from the edges of the button-hole opening so as to leave flat surfaces adjacent
to said opening the better to prevent the work from slipping when the button-hole is
being spread. It will be obvious that the construction above referred to may be
reversed by forming the concave grooves in the upper jaws if desired.
CRUIKSHANK & FAIRWEATHER,
Glasgow, Agents.

page_text: Improvements in Cloth Clamps for Button-hole Sewing
Machines.
I, ALEXANDER ANDERSON, Manager of the Singer Manufacturing Company's
Works Kilbowie, Dumbartonshire, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
My invention relates to that class of work clamps adapted to open and spread the
button-hole after the work has been clamped and it comprises certain improvements
on the clamp described in the Specification of Letters Patent No. 7508 dated June 19th
1885 the object of the present invention being to render my clamp more convenient
for use.
In the drawings Fig. 1 is a plan view of a clamp embodying my invention and Fig. 2
is a cross section of the same on the line 2-2 Fig. 1. Fig. 3 is a plan view with the
upper clamping jaws removed. Fig. 4 a partial plan view showing the lower jaws
spread apart. Fig. 5 is a side elevation of the clamp with the parts in the same
positions as in Fig. 1 and with the spreading lever in section. Fig. 6 is a detail view
of the spreading lever, and Fig. 7 a longitudinal section of the clamp.
A, denotes the base-plate of the clamp and B, B, the lower clamping plates or jaws
adapted to slide laterally on the base-plate, the lateral movements of these plates being
effected by a slide (having inclined ribs working in inclined grooves in the lower
surfaces of the plates B. The upper clamping jaws H are carried by arms attached
to plates or blocks G hinged to blocks 1, the latter blocks being attached to and
sliding laterally with the plates B. The jaws H are forced down against the plates I
by a cross-bar K connected by a link or pitman ♬ with a crank i on a small shaft I
having its bearings in the block F said shaft being operated by a clamping arm or
lever L attached thereto. All of the parts above-mentioned are or may be the same
as described in the Specification of the patent No. 7,508 herein before referred to.
In this my improved clamp the spreading lever D is pivoted by a pin d to a
stationary block a attached to the base-plate A, said lever being thus adapted to swing
horizontally and to move the spreading slide C back and forth by means of the
connecting link d loosely attached to said slide and lever. The clamping arm or
lever L is provided with a projection which is arranged to come into the path of
movement of a projection on the spreading lever D, as the latter lever is moved
inwards to bring the clamping jaws together prior to releasing the work when a
button-hole has been finished. This movement of the spreading lever will move the
clamping lever from the position shown by full lines to the position denoted by dotted
lines in Fig. 5, and the shaft I to which the clamping lever is attached will thus be
turned far enough in the direction denoted by the arrow in Fig. 7 to throw the crank i
over the dead centre, and the arms and clamping jaws H will then be instantly lifted
by springs placed between the blocks F and arms to the position indicated in
Fig. 7, thereby fully releasing the work. Thus it will be apparent that the work will

page_text: be released by operating the spreading lever only. In clamping the work and
spreading the button-hole the clamping fever is first turned to the position denoted
by full lines in Fig. 5 and the spreading lever is then moved to the position shown in
Fig. 4.
In order that the clamping jaws may hold the material securely with out requiring
too much force in clamping it has heretofore been customary to roughen their adjacent
surfaces to enable them to take a firm hold on the material, but this is objectionable
when working on finely finished leather and some other classes of work as the surface
of the material is more or less marred by the roughened surfaces of the clamping jaws.
To obviate this difficulty and still enable the clamping jaws to hold the work securely,
so that it will not slip when the button-hole is being spread, I have provided the lower
clamping jaws B with shallow concave grooves and the upper clamping jaws H,
with convex projections 2 fitting said grooves. These grooves and projections are
preferably slightly removed from the edges of the button-hole opening so as to leave
Hat surfaces adjacent to said opening the better to prevent the work from slipping
when the bution-hole is being spread.
It will be obvious that the construction above referred to may be reversed by forming
the concave grooves in the upper jaws if desired.
Having now particularly described and ascertained the nature of my said Invention
as communicated to me and in what manner the same is to be performed, I declare
that what I claim is:
1. In a button-hole work clamp, the combination with the upper and lower laterally
movable clamping jaws and a spreading lever therefor, of an independently movable
clamping arm or lever arranged to be engaged by the said spreading lever as the
latter is moved to bring the clamping jaws toward each other, substantially as set
forth.
2. In a button-hole clamp the combination with the laterally movable lower
clamping jaws or plates and a spreading lever for operating the same, of a clamping
arm or lever having a projection arranged to be engaged by the spreading lever, and
upper clamping jaws adapted to be raised to release the work when the said clamping
arm or lever is operated by the said spreading lever, substantially as set forth.
3. In a button-hole clamp the combination with the laterally movable upper and
lower clamping jaws and a spreading lever for operating the same, of a shaft having
a crank connected with the said upper clamping jaws, said shaft being provided with
a device adapted to be engaged by said spreading lever to throw the said crank past
the dead-centre, and springs for automatically lifting said upper clamping jaws, to
release the work, when the said crank is thus operated, substantially as set forth.
4. In a button-hole clamp the combination with the laterally movable upper and
lower clamping jaws and a spreading lever for operating the same, of a shaft having a
crank, a link and cross-bar for connecting said crank with the said upper jaws, a
clamping arm or lever having a projection adapted to be engaged by the spreading
lever and springs for automatically lifting said upper jaws when the said crank is
thrown past the dead-centre by the impingement of the spreading lever against the
clamping lever, substantially as set forth.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow,
Agents.