Year: 1886

page_text: wwww
1, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings in the County of Middlesex, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be par-
ticularly described and ascertained in and by the following statement:-
My invention relates to that class of scissors or shears in which the cutting
blades are held against each other by means of an adjustable spring arranged to
act on a loose bolt at the pivot-joint. The objects of my improvements are,-first,
to produce a uniform and adjustable pressure between the cutting blades at the
crossing edge; second, to lessen the cost of manufacture; and, third, to avoid the
unhealthy dry-grinding required in the manufacture of shears of ordinary con-
struction.
In the accompanying drawings Fig. 1 is a side elevation of a pair of shears with
my invention applied; Fig. 2 is a plan view of the same; and figs. 3, 4, 5 and 6
are views of the various parts detached. Similar letters refer to like parts through-
out the several views.
In figs. 1 and 2 A is the right hand blade and B is the left hand blade. Through
these blades at the pivot-joint passes the pivot-pin C, but it is not rigidly con
nected with either blade. The pin or bolt C. is shown in detail in figs. 3 and 4
a being a head, ba neck cut under said head a, c the portion of the bolt fitting
corresponding holes in the blades, A and B, and d a head to form a bearing against
the side of the blade B.
The screw E, shown in detail in fig. 6, has a head h of suitable form to be turned
with a wrench or other tool and a threaded end i fitting a correspon ling threaded
hole in the blade A. This screw E is for the purpose of adjusting the pressure of
the spring D upon the bolt C as will be next explained.
The spring D is bent near the centre, as shown in detail in fig. 5, at f. The
end e is slotted to fit the neck b of the bolt C. Near the end, admit the adjusting
screw E as shown in fig. 2. This spring bears on the blade A at a point or line
near the centre of said spring, the end e presses up under the heal a of the bolt C,
CD .

page_text: tending to draw the two blades together, while the end g of the spring is slightly
raised above the surface of the blade, but may be drawn nearer the surface by
secrewing in the adjusting screw E. By the arrangement described, when E is
screwed in, thus drawing down the end g, the end e is raised, thus increasing the
pressure with which the two blades are drawn together. By changing the position
of the screw E the pressure may be adjusted to any desired amount.
By the elasticity of the spring D the pressure is maintained at the crossing edge
of the blades even when not ground true. By reason of this spring attachment
and adjustable tension proper action is secured without the final dry-grinding to
bring the blades to perfect truth that is necessary in ordinary construction, thus
saving expense and doing away with a very unhealthy process.
The substitution of a loose joint-pin or bolt C in place of an accurately fitted
and rigidly secured one is another material saving in the expense of manufacture.
In the bolt C the neck 6 may be slitted on two sides, to receive the slot in the
end of the spring as shown in fig. 3, or it may be left round and the slot in the
spring made sufficiently large to accommodate it. The latter construction is shown
in fig. 4. With the former the bolt is prevented from turning, the head a is
preserved from serious wear, and the wear is brought upon the head d. In the
latter form as in fig. 4 the most wear comes upon the head a as the bolt is free to
turn and bring different parts into contact with the spring.
What I claim as my invention and desire to secure by Letters Patent is the
combination with a pair of shear blades, of a pivot-pin passing loosely through
both of said blades and having a head d at one end and a neck b at the other end,
a lever spring having a bend between its ends to serve as a fulcrum, bearing
against one of said blades, said spring being slotted at one end to embrace said
neck and an attaching and adjusting screw passing through said spring, near its
other end, substantially as set forth.
The combination with a pair of shear blades, of a pivot-pin passing loosely
through both of said blades and having a head d at one end and a neck h near the
other end, a spring having a bend near its center and slotted at one end to embrace
said neck and an attaching and adjusting screw passing through said spring near
its other end, substantially as set forth.
The combination with a pair of shear blades, of a pivot-pin passing loosely
through both of said blades, and having a head at one end and a neck near the
other end, a spring embracing said neck, and an attaching and adjusting screw
passing through said spring, substantially as set forth.
Dated thin 00nd day of Naam 1000
•
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.