Improvements in Cloth Clamps for Button-hole Sewing Machines.
Year: 1896

page_text: Date of Application, 7th July, 1396-Accepted, 30th Jan., 1877
COMPLETE SPECIFICATION.
Improvements in Cloth Clamps for Button-hole Sewing Machines.
We, THE SINGER MANUFACTURING COMPANY, of Kilbowie, Dumbartonshire,
Sewing Machine Manufacturers, and JOHN GORDON POLLOCK. Mechanic with.
said Company, at 17 Chiswell Street, Finsbury, London, E.C. 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:-
This invention relates to button hole cloth clamps of the kind described in the
Specifications of Letters Patent No. 7508 of 1885 and No. 5264 of 1886. for
opening up or spreading the button-hole after the fabric has been clamped, and
the present improvements have mainly for their object by suitable arrangement
of the parts to adapt such clamps for spreading the button-hole when such is cut
parallel with instead of at right angles to the edge of the fabric operated on.
The invention is illustrated by the accompanying drawings,
Fig. 1 of which is a plan of the improved button-hole cloth-clamp shewing
the upper clamping jaws raised out of contact with the lower clamping.plates,
Fig. 2 a vertical section on the line a- of Fig. 1,
Fig. 3 is a plan shewing the upper and, lower clamping jaws in contact, and the
jaws moved apart so as to spread the button-hole,
Fig. 4 is a side elevation of Fig. 3. shewing the fabric y clamped between
the jaws.
Fig. 5 is a plan of the base plate and spreading slide,
Fig. 6 is an inverted plan of the lower clamping plates,
Fig. 7 shews the mode of attachment of the forward upper clamping jaw to the
rear upper jaw, and
Fig. 8 is an enlarged view shewing the formation of the teeth of the forward
clamping jaws.
The base plate A of the clamp has two sets of undercut parallel guides A¹
removably secured thereto, in which work the lower.clamping plates B, B', which
have their lips.b, b', fitted beneath.overhanging lips a, a, on the parallel guides A¹.
The clamping plates B, B', have on their under sides inclined grooves 3,63, in
which act inclined ribs c formed on a spreading slide C movable in a recess a
in the base plate A, the slide C being connected by a link d with a lever D
pivoted on one of the guides A'. The lever D is operated by hand to impart
movement in either direction to the spreading slide C and the inclined ribs c
thereon traverse the grooves 2, 3, in the lower clamping plates B, B', and thereby
cause the plates to approach or recede from each other. Two blocks F rigidly
secured to and moving with the rear lower clamping plate B' have plates F¹ hinged
to them at f which carry arms F2 to whose outer ends is secured the rear upper
clamping jaw G, the forward upper clamping jaw G₁ being connected to the
jaw G by springs g and guided in its movement to and from the rear jaw G by
guide fingers 9 formed on the rear jaw and entering grooves g in the forward
jaw G. A shaft E is journalled in these blocks F the shaft E having a lever e
secured on one end and a crank e' being formed on the shaft and connected by a
link or pitman e² to a cross bar e forked at each end, the forked ends embracing
the arms F2 carrying the upper clamping jaws G, G¹. This cross bar e bears on
the arms F to clamp the jaws G, G', upon the lower clamping plates B, B', against

page_text: the action of springs e situated between the arms F and the blocks F, when it is
desired to secure the fabric.
The action of the clamp is as follows:-
The fabric is placed between the upper and lower jaws when these are in the
position shewn by Figs. 1 and 2 the jaws being thereafter clamped as shewn by
Figs. 3 and 4 by turning the lever e secured on the shaft E, the crank el being
brought to a position just past the dead centre to effect this and the further move-
ment of the lever being prevented by a pin e in one of the blocks F. The lever D
is now moved in the direction of the arrow, Fig. 1, and by the action of the ribs c
of the slide C upon the grooves 63, 63, in the lower clamping plates B, B', the
latter are spread and draw apart the fabric on each side of the button-hole. The
rear upper jaw G being connected to the blocks F on the lower clamping plate B
moves with the said clamping plate B but the forward upper jaw G being
independent of the forward lower jaw B' is operated therefrom only through the
fabric which is clamped between them, the formation of the teeth on the jaw G¹
being such that they interlock as shewn at Fig. 8 and the fabric in being spread
engages the sharp points of the teeth and serves to draw outwards the said jaw.
To further facilitate the spreading operation, short prongs g³ are formed on the
lower side of the jaw G¹ which enter holes & ou the lower clamping plate B.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. A button-hole clamp the parts of which are constructed, arranged and
combined substantially as described.
2. In a button-hole clamp of the class set forth the arrangement of the clamping
jaws and the operating mechanism for spreading button-holes cut parallel to the
edge of the fabric substantially as described.
3. In a button-hole clamp of the class set forth, the improved construction and
arrangement of the clamping jaws, one mounted on and rigidly connected with the
rear lower plate and the other movable on the first and operated against the
power of springs by the forward lower plate through the engagement of the fabric
with the movable jaw, substantially as described.
4. In a button-hole clamp of the class set forth the formation of the forward
lower plate and movable jaw with interlocking teeth. adapted to engage the
fabric so that the movable jaw is drawn outwards by the lower plate through the
fabric, substantially as described.
Dated this 6th day of July 1896.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62 St. Vincent Street, Glasgow, Agent for the Applicant.