Year: 1888

page_text: 1. GEORGE RUSSELL, Alpha Works, Motherwell, Lanarkshire North Britain Engineer
do hereby declare the nature of this invention to he as follows:-
The object is improvements in traversing the load in hoisting sheers or sheer legs.
The back leg is pivotted at lower end to a fixed centre, and the movement of the load
horizontally is caused by varying the length of the back leg. According to one
modification, the lower end of back leg consists of two flat guides or slides, rather
longer than the difference between the longest and shortest length required. The
lower end of these guides have a pin at fixed centre on which they hinge. The
upper portion of back leg contains near its lower end a screwed nut in which
the main screw revolves. The two flat guides are arranged, one on each outside
of upper portion, with rollers or other appliances so that the upper and lower portions
will be always in a straight line, notwithstanding variation of the total length. Near
the lower end of flat guides and connecting them together, is a bearing for lower end
of main screw, and below this bearing is a bevil wheel fixed on end of main screw,
between the flat guides, and gearing into another bevil wheel on a shaft, passing
through and concentric with, the fixed centre at lower end; through which the power
is conveyed for revolving the main screw.
1 1000

page_text: I, GEORGE RUSSELL, Alpha Works, Motherwell, Lanarkshire, North Britain,
Engineer, 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 the traversing motion of Machines for hoisting, lowering
and traversing loads, known as "Sheers" or "Sheer Legs." These are usually made
with two front legs A. B, see Fig. 1, and one back leg A C. The front legs are
spread apart at bottom, so that the load D may pass between them in moving
from D to D 2: this movement being effected by pulling in the front legs from A
to A 2, moving on B as a centre. This movement is usually effected by moving (
horizontally, the length A C remaining constant.
According to my Invention, this movement is obtained by shortening the
back leg when load is moved inwards, and lengthening it when moved outwards.
The object of my Invention is to economise space, protect main screw from dust,
and lessen power required.
Figs. 2 and 3 shew one modification, being two views of the lower portion of back
leg. The centre pins C, are fixed in suitable brackets, to which are attached two
guide bars E, E, fixed to cross bracket F, which contains thrust bearing in which
revolves the main screw G: the power being communicated by the bevil wheels H H
from driving shaft J. The main screw works into the nut K, and is sufficiently long
to obtain a travel equal to the difference in length between AC and A 2, C. The
nut K is carried in brackets inside the upper portion of back leg, which is of a box
or tubular section: the lower end of this part has four flanged rollers L L L L, which
hear on the edges of guides E, E and keep the upper and lower parts of the back leg
truly in line. The upper ends of guides E E, are connected together by a frame
enclosing upper part of back leg.
A second modification is shewn in Fig. 4. Instead of the side guides and rollers,
for keeping the upper and lower parts of back leg in line exact: it may be
approximately so kept, by a radial bar or bars M N moveable on a fixed
centre N.
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 [
claim is
The arrangement of driving, guiding and enclosing the main screw of Hoisting
Sheers, substantially as herein described, and for the purpose herein set forth.
Datad this Sixteenth day of January 1889