Improvements in Hydraulic Lifting Jacks.
Year: 1890

page_text: Date of Application, 26th Mar., 1890
Complete Specification Left, 25th June, 1890-Accepted, 9th Aug., 1890
PROVISIONAL SPECIFICATION.
Improvements in Hydraulic Lifting Jacks.
We TANGYES LIMITED of Cornwall Works Soho in the County of Stafford Engineers
and THOMAS MEACOCK of No. 2 Waverhill Road Handsworth in the County of
Stafford Mechanical Engineer and GEORGE DEAKIN of No. 41 Thomas Street
Smethwick in the County of Stafford Mechanical Engineer do hereby declare the
nature of this invention to be as follows:-
The said invention consists in constructing and arranging the parts of hydraulic
lifting jacks in the manner hereinafter described whereby the ram of the jack at all
stages of its protrusion and the height of the jack so reduced as to render it
much more convenient in use than hydraulic jacks of the ordinary construction.
In constructing a hydraulic jack according to the said invention we employ a
stationary cylinder provided with a base or foot. In this cylinder the hydraulic ram
works. This ram has a cupped or other packing at its bottom end. Surrounding
the said cylinder is a cylindrical casing the bottom end of which has a claw.
The top of the said casing is provided with a checquered cover attached thereto by
screws.
The upper part of the said casing constitutes a cistern for containing the liquid with
which the jack is worked. A thrust collar is formed at the bottom of the cistern
against which collar the shoulder of the ram presses in lifting.
The actuating pump is placed in a recess formed in the top of the ram.
This pump
consists of a body or cylinder with a delivery valve at bottom. A plunger with a
suction valve works in the said body or cylinder. An axial hole is drilled in the said
plunger which hole communicates with a cross or transverse hole in such a position
as permits suction being effected from the lowest position. The placing of the pump
in the recess described effects great reduction in the height of the jack. This reduced i
height is of great importance for general purposes.
The pump is worked by a hand lever on one end of a cross axis. To lower the
jack at pleasure a screw release valve is provided by operating which the pressure
liquid in the cylinder may be permitted to return to the cistern. An air screw is
provided at the top of the cistern by removing or relaxing which the air which had
been dissolved by the water and which had been liberated is permitted to escape.
In order to prevent the ram being raised too high an escape hole is made in the
cylinder at the point to which it is desired to limit the ascent of the ram.
Dated this 26th day of March 1890.
W. T. WHITEMAN,
Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Hydraulic Lifting Jacks.
We TANGYES LIMITED of Cornwall Works Soho in the County of Stafford Engineers
and THOMAS MEACOCK of No. 2 Waverhill Road Handsworth in the County of
Stafford Mechanical Engineer and GEORGE DEAKIN of No. 41 Thomas Street.
Smethwick in the County of Stafford Mechanical Engineer do hereby declare the
nature of the said invention and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement:-
The said invention consists in constructing and arranging the parts of hydraulic
lifting jacks in the manner hereinafter described, whereby the ram is protected at all
stages of its protrusion and the height of the jack so reduced as to render' it much
more convenient in use than hydraulic jacks of the ordinary construction.

page_text: In constructing a hydraulic jack according to the said invention we employ a
stationary cylinder provided with a base or foot. In this cylinder the hydraulic ram
works. This ram has a cupped or other packing at its bottom end Surrounding
the said cylinder is a cylindrical casing the bottom end of which has a claw. The top
of the said casing is provided with a chequered cover attached thereto by screws.
The upper part of the said casing constitutes a cistern for containing the liquid with
which the jack is worked. A thrust collar is formed at the bottom of the cistern
against which collar the shoulder of the ram presses in lifting. The actuating pump
is placed in a recess formed in the top of the ram. This pump consists of a body or
cylinder with a delivery valve at bottom. A plunger with a suction valve works in
the said body or cylinder: An axial hole is drilled in the said plunger which hole
communicates with a cross or transverse hole in such a position as permits suction
being effected from the lowest position. The placing of the pump in the recess
described effects great re luction in the height of the jack. This reduced height is of
great importance for general purposes.
The pump is worked by a hand lever on one end of a cross axis. To lower the
jack at pleasure a screw release valve is provided by operating which the pressure
liquid in the cylinder may be permitted to return to the cistern. An air screw is
provided at the top of the cistern by removing or relaxing which the air which had
been dissolved by the water and which had been liberated is permitted to escape.
In order to prevent the ram being raised too high an escape hole is made in
the cylinder at the point to which it is desired to limit the ascent of the ram.
We will now proceed to describe with reference to the accompanying Drawing the
manner in which the said invention is to be performed.
Figure 1 represents in vertical section a hydraulic lifting jack the parts of which are
constructed and arranged according to this invention. Figures 2 and 3 are elevations
of the same the cylindrical outer casing of the jack being represented in its lowest
position in Figure 2 and in its highest position in Figure 3. Figure 4 represents a
cross section of the jack and Figure 5 represents a section of the pump plunger taken
in a plane at right angles to that in which the section of the pump plunger represented
in Figure 1 is taken.
The same letters of reference indicate the same parts in the several Figures of
the Drawing
a is the stationary cylinder of the jack having a base or foot on which it is supported:
e is the hydraulic ram working in the said stationary cylinder a and c is the cupped
(or other) packing at the bottom of the said ram as represented; d is the cylindrical
casing surrounding and sliding upon the fixed ram cylinder a. The bottom end of
the said cylindrical casing d carries a checquered claw 2 on which the article to
be lifted may rest and the top of the casing d is provided with a checquered
cover d³ on which the article to be lifted may be placed. The jack represented is
thus fitted for lifting either from the top or from the claw at bottom as may be
required. When the jack is required to lift from the top only the claw dis
omitted. In order to prevent angular motion of the cylindrical casing d carrying
the claw d upon the fixed ram cylinder a so as to preserve the said claw d² in line
with the projection on the foot b on the ram cylinder a we prefer to make the
exterior of the ram cylinder a of an eccentric form in cross section so that the said
casing d cannot turn on the said cylinder a. Or the same effect may be produced by
making one or more vertical projections or ribs on the said cylinder a working in
corresponding slots or grooves in the outer casing d e is the cistern at the upper part
of and in one piece with the cylindrical casing d for containing the liquid with which
the jack is worked; d' is an internal shoulder or collar at the bottom of the cistern e
for the shoulder of the ram e to press against in lifting. The actuating pump of
the jack is situated in the recess at formed in the top of the ram c the pump
cylinder being marked and the plunger working therein (shown separately in
Figure 5) being marked h.
The bottom of the plunger h carries a suction valve
opening downwards and the bottom of the pump cylinder carries a delivery valve
also opening downwards as seen in Figure 1. It will be seen by reference to
:

page_text: Figures 1 and 5 that an axial hole is drilled in the plunger which hole communicates
with a cross hole h² at one side of the plunger. This cross hole * permits of
suction being effected from the lowest part of the cistern e. The pump plunger h
is worked by a hand lever on the square end 2 of the cross axis i which axis has a
rocking motion given to it by the said hand lever. The rocking motion of the axis i
communicates a reciprocating motion to the pump plunger h by means of a cam
or arm on the hexagonal middle part of the cross axis i working in a slot /³
in the said plunger. By the motion of the said cross axis & arm or cam and⚫
pump mechanism the liquid from the cistern e is pumped between the bottom of
the ram c and the bottom of the fixed cylinder a and the said ram is raised in the
said cylinder carrying with it the outer casing d and the parts in connection with the
said outer casing as illustrated in Figure 3. In order to lower the jack the screw
release valve is opened. By the opening of the valve the pressure liquid is permitted
to return to the cistern e the said liquid passing by the axial passage in the ram e the
passage between the pump cylinder and rain and the passages in communication
with the seat of the screw release valve as seen in Figure 1. By means of the air
screw at the top of the cistern e the air liberated from the liquid in the said cistern e
may be permitted to escape. The ascent of the ram c is limited by the use of the
liquid escape hole at m in the cylinder a (see Figure 1).
When the bottom of the ram rises above the said hole at m the pressure liquid
passes through the said hole into the annular space represented between the fixed
cylinder a and the outer cylindrical casing d and thereby prevents the ram being
raised too high.
The jack represented may be converted into a traversing jack by mounting it upon
the ordinary screw traversing base of a traversing jack,
By arranging the pump of the jack in the top of the ram as represented the
height of the jack is reduced and by combining with the fixed cylinder a of the
jack the cylindrical sliding casing d the rame is protected at all stages of its pro-
trusion.
Having now particularly described and ascertained the nature of the said inven-
tion and the manner in which the same is to be performed we declare that we claim
as the said invention of "Improvements in hydraulic lifting jacks
-
"
:-
First The combination with the upper part of the ram of the hydraulic lifting
jack of the actuating pump of the jack for the purpose and substantially as hereinbefore
described and illustrated in the accompanying Drawing.
Secondly-The combination with the fixed hydraulic cylinder of the jack in which
the ram works of an outer cylindrical sliding casing carrying the cistern and parts for
working the pump for the purpose and substantially as hereinbefore described and
illustrated in the accompanying Drawing.
:
Thirdly The general arrangement or combination of the parts of hydraulic
lifting jacks hereinbefore described and illustrated in the accompanying drawing.
Dated the Twenty-third day of June 1890.
TANGYES LIMITED.
H. J. Parkins,
Secretary.
THOMAS MEACOCK.,
GEORGE
DEAKIN.