Improvements in and relating to Stone Sawing Machinery.
Year: 1896

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Stone Sawing Machinery.
We, GEORGE RUSHWORTH and JOHN RUSHWORTH of Primet Bridge Iron
Works, Colne, in the County of Lancaster, Engineers and Contractors' Plant
Manufacturers, 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 more particularly to stone sawing machinery, for which
Letters Patent were granted to the said George Rushworth and John Rushworth
No. 22,879 dated 26th November 1894.
In the said Specification, the connecting rod with the prime mover is shewn as
being connected at one end of the saw frame to a cross shaft, extending from one
side to the other of the tension plates. Now, we find in this arrangement, there is
a considerable thrust or drag on the frame, saw blades and crank shaft, which
interferes to some extent with the easy working of the machine.
In the present invention, in order that the motion of the connecting rod may be
equally distributed to the whole frame, we connect the connecting rod to a shaft
about midway of the frame, the said shaft being secured to strong side plates,
bolted to the top and bottom stay pieces of the frame, in addition to or in substitution
of a portion of the lattice work.
The motion of the frame is thus uniform, which is of great importance, when the
saws have to,cut to some depth in the stone.
In the accompanying drawings,
Fig. 1 is a front view of our stone saw frame improved as described..
The shaft A of the connecting rod B is removed from the end to about midway
of the saw frame, and mounted in strong side plates C bolted to top and bottom stay
pieces D of the frame. In this way, we obtain a direct motion and straight cut,
whatever depth it is required to cut the stone.
The next part of our invention relates to the means employed for raising and
lowering the stone saw frame, and.consists in the employment of two screw shafts
on each side, or four altogether in number, instead of one screw shaft on each side
as in our last arrangement. This arrangement is more particularly serviceable for
the larger type of machines.
Figs. 2 and 3 are side elevation and plan view respectively of our saw frame,
modified in this way. E E are the two vertical screw shafts, (similar shafts being
on the other side of the machine) which raise and lower sliding head piece F of saw
frame G, in the manner fully described in our former Patent. As seen in plan
view Fig. 3, screw shafts E E are operated by bevel wheels H from horizontal
shafts J, which derive their motion from transverse shaft K by bevel gear L, the
driving arrangement for raising and lowering the saw frame being identical with
that described in our said recited Patent Specification.
The next portion of our invention consists of an improved means of securing the
aw blades in order to prevent them warping or buckling.
This we accomplish by employing in addition to the usual dogs and cottars
for holding the saw blades, clamp pieces or clips, which grip the saw blades on each
ide.
From side to side of the tension plates or frame carrying the blades, we fix two
crew shafts, one above and one below the saw blades. These are secured by nuts.
A couple of clamp pieces are used for each saw blade, one on each side thereof.
In order that they may be readily mounted on the top and bottom screw shafts

page_text: they are preferably provided with open slots to fit on the shafts, so that they may be
put in place without removing the shafts. The clamping pieces are formed slightly
bent to receive the saw blades, and when got in position are clipped against the
face of the saw blade, and at the same time are bound together or one against the
other, by nuts on each side thereof respectively, which are tightened on the screw
shafts by a key or wrench, thus bringing the clamping pieces together on each side
against the face of each saw. In this way, the saw blades are held or gripped as
in a vice, and there is not therefore the same tendency to buckle or swerve from
their true direction whilst cutting the stone.
Figs. 4, 5, and 6 are views representing our improved arrangement of securing
the saw blades.
Referring to Fig. 4, M M are the screw shafts, which extend from one side
to the other of the tension plates, and above and below the saw blades. On these
shafts we place clamp pieces or clips N, formed with open slots to fit shafts O, and
tightened one against the other on each side of saw blades M by nuts P, whereby
the saw blades are firmly held as in a vice, and prevented from buckling or swerving.
Figs. 5 and 6 are side views of clamp pieces N formed with open slots PQ, for
readily fitting on or taking away from screw shafts M, without removing the shafts,
all that is necessary being to unscrew or tighten nuts P as the case may be.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The improved means of steadying the movement of the saw frame by removing
the connecting rod B and its shaft A to about midway of the saw frame, the said
shaft being mounted on side plates bolted to the saw frame, substantially as
described and illu: trated in Fig. 1.
2. The combination of two screw shafts, on each side of the machine, or four in
number, for raising and lowering the saw frame, substantially as described and
illustrated in Figs. 2 and 3.
3. The improved arrangement for preventing the saw blades from buckling or
swerving from their true direction whilst sawing the stone, substantially as
described and illustrated in Figs. 4, 5 and 6.
Dated this 9th day of March 1806
F. RICHMOND,
12, Standish Street, Burnley, Agent for the Applicants.