IMPROVEMENTS IN NIPPERS FOR CUTTING WIRE AND OTHER SIMILAR PURPOSES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the
Office of the Commissioners of Patents on the 17th October 1883. Commu-
nicated to him from abroad by Seymour Lee of Windsor in the County of
Windsor and State of Vermont, United States of America
"
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of 53 Chancery
Lane in the County of Middlesex, Fellow of the Institute of Patent Agents,
"IMPROVEMENTS IN NIPPERS FOR CUTTING WIRE AND OTHER SIMILAR PURPOSES."
[communicated to him from abroad by Seymour Lee of Windsor in the County of
Windsor and State of Vermont, United States of America]
This Invention relates to cutting nippers such as are used by tin-men and others
for cutting off wire, rivets, and for similar purposes.
Heretofore the lever parts of such nippers have been generally made each of a
single piece only of wrought iron, the fulcrum being upon a rivet connecting the
two parts and of a separate piece of metal; the cutters or cutting edges have
generally been made of steel and welded upon the iron parts. The cutters have
also been made of separate pieces of steel and have been secured by means of
screws to the front faces of the lever parts. The cutters have also been made
of separate pieces of steel and have been secured to the lever parts by means of
dovetail grooves in the said parts, the cutters being so formed as to fit and be
driven lengthwise into said grooves.
The first method is objectionable by reason of the expense and difficulty of the
manufacture particularly of the joint or fulcrum part of the forging, and also that
great care is necessary to properly weld the steel cutter to the lever parts without
over-heating and consequent injury to the former, and also that when by breakage
or wear the cutting edges become impaired, they are extremely difficult to repair.
The second method is objectionable by reason of the liability of breakage or
loosening of the screws holding the cutters in place, the great exactness necessary
in manufacture in order that duplicate cutters may correspond to and fit exactly
any of the parts for which they may be needed; also from the fact of there being
but one available cutting edge upon each cutter.
The third method is objectionable for the reasons that the cutters are complicated
in shape and difficult of manufacture to such exactness and uniformity as to
perfectly fit any nipper for which they may be needed. Also in that certain strains

page_text: to which the cutters are subject in use, are liable to open and enlarge the dovetail
grooves into which the cutters are fitted and thus render them loose and liable to
work out from their proper places.
The object of this Invention is to provide a cutting nipper in which the lever
portions are of such construction as to admit of their convenient manufacture in
which the fulcrum or pivot upon which the parts work is made in one piece with
the parts forming one of the main levers in which the detachable cutter is cheap
and simple of manufacture and of a shape which shall by being simply reversed in
its position, present a second and new cutting edge for use. Also to provide such
a method of fitting the cutters to the nippers as shall ensure their perfectly secure
attachment and at the same time easy removal and insertion without great exactness
being requisite in the fitting of the same.
The Invention consists in the construction of one of the main levers of the nipper
in sections or halves each extending the full length of the lever and of such shape
as to admit the other main lever working between them on a fulcrum formed of a
cylindrical boss on the inner face of each half and forged in one therewith. The
said bosses enter a hole made in the other lever at opposite sides and meet in the
middle and thus form the pivot or fulcrum upon which the levers work. When
the parts are thus put together, they are firmly united by rivets, of which one
passes through a central hole drilled through the said bosses. The one lever being
thus made in two separate parts may be readily finished about the fulcrum or pivot
before the .putting together of the parts. The pivot being forged solid with the
parts of the lever, ensures additional strength and durability of the joint.
The Invention also consists in the position and shape of the recesses or grooves
in the lever jaws for the reception of the removable and reversible cutters; also in
the peculiar transverse sectional shape of said cutters by which two cutting edges
are formed on each cutter; also in the longitudinal shape of said cutters which, in
connection with the recesses or grooves in the jaws of the levers, ensures the cutters
being securely held in their proper places whilst permitting of their easy insertion
and removal. The said recesses or grooves are slightly wider than the thickness of
the cutters and are at such an inclination that the inner faces of the cutters will
be at the proper angle for the inner faces of the cutting edges. The two long edges
of each cutter are similarly bevelled on the outer face to form cutting edges both on
the front and back of the cutter. Before hardening and tempering the cutters they
are slightly bent or bowed longitudinally so that when driven endwise into their
places they will become nearly straightened and will by their constant tendency to
resume their bowed shape be sufficiently bound to prevent their becoming loose or
working out of place.
In case of a cutting edge becoming damaged or dulled, the cutter can be readily
taken out and reversed in its positi n, bringing its opposite and similar edge into
use.
In the same manner new cutters may be put in place of old, a sufficient fit
for their security being ensured by the bowed shape given to the cutters. In the
operation of cutting wire or rivets the tendency of the strain thus put upon the
cutters is from their positions, such as to force them more firmly and exactly into
their proper positions.