IMPROVEMENTS IN THE MEANS OF OB APPARATUS FOR RAISING, LOWERING, AND SPLITTING STONE
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the Office of
the Commissioners of Patents on the 20th January 1879. A communication
from abroad by Thaddeus Norris, junior, of Philadelphia, Pennsylvania,
United States of America.
JOHN HENRY JOHNSON, of 47, Lincoln's Inu Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE MEANS OF OB APPARATUS FOR RAISING,
LOWERING, AND SPLITTING STONE." A communication from abroad by Thaddeus
Norris, junior, of Philadelphia, Pennsylvania, United States of America.
This Invention relates to apparatus for use as a lewis or medium in connection
with suitable tackle for raising and lowering stones without making in the latter
the usual undercut recess, a simple cylindrical recess drilled in the stone being all
that is required to receive the lewis, but the apparatus is also capable of being
utilized for splitting stone in the manner hereinafter described.
In carrying out this Invention as applied to the raising and lowering of stones
a bolt is employed, provided at the lower end with a circular enlargement or head,
and at the upper end, which is threaded with a nut having an eye for receiving
the hook of any hoisting tackle. Between the head of the bolt and the nut
intervenes a metal tube, a metal washer, and any desired number of rubber rings,
say for example three; or a single ring of rubber may be used in some cases, and a
number of metal rings or washers may be used in place of the metal tube. In lieu
of forming in the stone to be hoisted the undercut recess, which an ordinary lewis
demands, and which cannot be made without tedious manipulation, a simple
circular recess is drilled in the stone for the reception of the improved lewis, which
is dropped into the said recess while the rubber rings are contracted owing to the
nut being loose. After the lowis has been thus deposited in the recess of the stone
the nut is tightened, so as to compress the rubber rings and expand them against
the sides of the recess until the lewis is so jammed therein that it becomes a secure
medium through which the stone can be raised and lowered.
When the nut is unscrewed and pressure thus removed from the rubber rings
the latter will contract, and the lewis will be at liberty to be withdrawn from the
recess in which the tube and head fit freely. Both however should be of such a
diameter in respect to the recess that the projection beyond them of the rubber
rings when the latter are compressed shall be as little as possible.
The bolt may be made to terminate at the top in a hook, and be secured at the
bottom to a collar or nut, the compression of the rubber rings being effected by a
wedge shared key.

page_text: Or the head of the bolt may be arranged immediately below the eye, and bear
on the top of a tube containing an inner tube, the upper portion of which con-
stitutes the nut of the bolt. The rubber rings are confined between a flange on
the inner tube and the lower end of the outer tubo.
Rings of rubber are not essential in carrying out this Invention; a strip of
rubber for instance may be coiled in the space between the head of the bolt and
the washer, or a coil of rope or leather may be used, or indeed any material which
will yield under pressure and can be expanded laterally thereby against the sides
of the recess may be employed, providing it will recoil so far on the removal of the
pressure as to permit the lewis to be withdrawn from the recess.
When the apparatus is used for splitting stone this operation is performed by
expanding in an orifice bored therein the rubber or other equivalent yielding
material.
It is preferred however to make the instrument when used for splitting stone
much longer than the lewis. The nut of the bolt also consists of the hub of a
wheel, in the rim of which may be orifices for the insertion of bars or levers.
The Invention may be adopted in quarrying in place of ordinary blasting
operations; for example, a hole may be drilled in a rock in the inclined direction,
the instrument introduced into the hole, and the nut turned through the medium
of a powerful leverage until the expansion of the rubber splits off the overhanging
portion of the rock. If the mass of rock is large two or more holes may be drilled
at such points as the desired fracture may suggest, and one of the instruments
introduced into each hole, and the nuts of all the instruments tightened.
As in the case of the lewis it is not essential that rubber should in all cases be
used; a coil of rope for instance may be interposed between the head of the bolt
and the end of the tube, or leather may be used, or indeed any material which will
yield under pressure, and which possesses inherent elasticity, may be employed.