IMPROVEMENTS APPLICABLE TO LIFTS OR HOISTS
Year: 1878

page_text: LETTERS PATENT to Astley Paston Price, of 47, Lincoln's Inn Fields, in the
County of Middlesex, for the Invention of "IMPROVEMENTS APPLICABLE TO
LIFTS OR HOISTS." A communication from abroad by Emile Heurtebise, of
Paris, in the Republic of France.
led the 25th April 1879, and dated the 1st November 1878.
66
PROVISIONAL SPECIFICATION left by the said Astley Paston Price at the
Office of the Commissioners of Patents on the 1st November 1878.
ASTLEY PASTON PRICE, of 47, Lincoln's Inn Fields, in the County of Middlesex.
IMPROVEMENTS APPLICABLE TO LIFTS OR HOISTS." A communication from
abroad by Emile Heurtebise, of Paris, in the Republic of France.
This Invention relates to a hydraulic safety apparatus or brake more particularly
applicable to direct-acting lifts or hoists, that is to say, those in which the load is
supported directly by the rod of the ram or plunger piston serving to elevate it,
and which is balanced by counterweights.
The connection of the cage, for example, in the case of an ordinary lift with the
rod of the ram or piston may be so formed as to obviate all liability of the two
parts becoming separated, and the sole possible cause of accident is the rupture of
the chain of the counterweights. It is evident that in case of such rupture taking
place, the cage with the persons or other weights with which it is loaded, and the
ram or plunger piston being no longer supported by the counterweights, will des-
cend with rapidity which increases continually, the ram or plunger piston re-entering
the cylinder and rapidly forcing back the water through the discharge orifice or
through the inlet orifice according as the accident takes place during an ascent or
descent of the cage.
Hence it is apparent that the rupture of the connection with the counterweights
results in an increase of pressure on the water contained under the ram in a pro-
portion which principally depends upon the weight of the said arm and of the load
which it carries.

page_text: This Invention consists in utilising the excess of pressure which is generated in
the cylinder of the lift at the moment when a rupture occurs for the purpose of
automatically closing the orifice-of-the-water-by-means-of-an-apparatus suitably-
arranged, and consequently forming a stationary column of water under the ram
which supports it in a fixed position with its load, thus obviating all danger of
further-injury..
An apparatus of this description forms in principle a safety valve interposed
between the distributing valve and the ram cylinder, and loaded to support the
greatest normal pressure in the apparatus, that is to say, a pressure slightly in
excess of that of the water on admission, this valve being arranged so as to inter-
cept-all-communication-between-the-cylinder and the pipe connected with its lower
end directly the pressure in the cylinder exceeds the limit of normal maximum
pressure at which the lift is to be worked.
In carrying out this Invention the apparatus is composed of a vertical tube pro-
vided with two horizontal tubular connections, and at its lower end closed by a
disc perforated with a small orifice, and at its upper end closed by a cover through
which is passed a rod carrying a roller at its upper extremity, and forming part of
a hollow cylinder which fits into the lower part of the tube. The upper part of
this cylinder is provided with an enlargement or piston working in the upper part
of the tube (which is made of corresponding size), suitable leather packing rings
being provided both on the cylinder and on the piston to prevent leakage, and the
orifice in the disc admits of the escape of any water which may gain access beneath
the cylinder in consequence of any imperfections in the joint, and ecsures the proper
working of the apparatus.
The cylinder is provided with two apertures similar to those in the plug of a
stop cock and which allow free communication between a distributing valve and
the cylinder of the ram of the lift or hoist when the said apertures are situate
opposite the two tubular connections, as is the case when the movable cylinder is
in its lowest position.
The diameter of the piston which forms part of the movable cylinder being
greater than that of the cylinder, an annular space is formed underneath the former
which is exposed to the pressure of the water.
The piston forms part of a rod which is bifurcated at its upper extremity and
carries a roller supporting a lever jointed at one end to a fixed bar, and loaded at
the other end with a weight calculated according to the length of the lever and the
maximum pressure which the piston is required to resist without rising.
From the foregoing it is evident that a slight excess of pressure exerted on the
annular piston will cause the movable cylinder to rise, and with it the apertures,
thus partially or wholly closing the tubular connections and restraining or entirely
arresting the flow of the water from under the ram cylinder, and thereby retarding
or suspending the motion of the cage.
It is evident that this improved apparatus will act not only as a brake in case
of accident but even as a regulator of the motion when the cage is descending over
loaded, as the excess of pressure will then cause the piston to rise to a certain
extent and with it the cylinder, thus reducing the sectional area of the channel for
the escape of the water.
The counterweight employed for balancing the pressure to which the piston is
exposed may obviously be replaced by a spring acting upon the piston either
directly or through the intervention of a lever.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Astley Paston Price in the Great Seal Patent Office on the 25th April
1879.
ASTLEY PASTON PRICE, of 47, Lincoln's Inn Fields, in the County of Middlesex.
"IMPROVEMENTS APPLICABLE TO LIFTS OR HOISTS." A communication from
abroad by Emile Heurtebise, of Paris, in the Republic of France.
The said Invention relates to hydraulic safety apparatus or brake more par-
ticularly applicable to direct-acting lifts or hoists, that is to say, those in which the
load is supported directly by the rod of the ram or plunger piston serving to elevate
it, and is balanced by counterweights.
In the case of an ordinary lift the connection of the cage, for example, with the
rod of the ram or piston, may be so formed as to obviate all liability of the two
parts becoming separated, and the sole possible cause of accident is the rupture of the
chain of the counterweights. It is evident that in the case of such rupture taking
place the cage with the persons or other weights with which it is loaded, and the
ram or plunger piston being no longer supported by the counterweights will
descend with a rapidity which increases continually, the ram or plunger piston
re-entering the cylinder and rapidly forcing back the water through the discharge
orifice or through the inlet orifice, according as the accident takes place during an
ascent or descent of the cage. Hence it is apparent that the rupture of the con-
nection with the counterweights results in an increase of pressure on the water
contained under the ram in a proportion which principally depends upon the weight
of the said ram and of the load which it carries.
Now the said Invention consists in utilising this excess of pressure which is
generated in the cylinder of the lift at the moment when a rupture occurs, for the
purpose of automatically closing the orifice of the water by means of an apparatus
suitably arranged, and consequently forming a stationary column of water under
the ram which supports it in a fixed position with its load, thus obviating all
danger of further injury.
An apparatus of this description forms in principle a safety valve interposed
between the distributing valve and the ram cylinder, and loaded to support the
greatest normal pressure in the apparatus, that is to say, a pressure slightly in
excess of that of the water on admission, this valve being arranged so as
to intercept all communication between the cylinder and the pipe connected with
its lower end directly the pressure in the cylinder exceeds the limit of normal
maximum pressure at which the lift is to be worked.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Drawings illustrates the general arrangement of
a direct-acting lift or hoist with the automatic safety apparatus applied thereto
according to the said Invention between the distributing valve and the cylinder.
Figure 2 represents a sectional elevation drawn to a larger scale of the safety
apparatus detached, and
Figure 3 is a sectional plan of the same.
The apparatus is composed of a vertical tube a provided with two horizontal
tubular connections d, d, and at its lower end closed by a disc b perforated with a
small orifice c, and at its upper end closed by a cover e through which is passed a
rod f, carrying at its bifurcated upper extremity o a roller g, and forming part of a
hollow cylinder which fits into the lower part of the tube a.
The upper part of the cylinder h is provided with an enlargement or piston ¿
working in the upper part of the tube a (which is made of corresponding size),
suitable leather packing rings j, j, being provided both on the cylinder and on the

page_text: piston to prevent leakage, whilst the orifice c in the disc admits of the escape of
any water which may gain access beneath the cylinder in consequence of any
imperfections in the joint, and ensures the proper-working-of-the-apparatus.-
The cylinder is provided with two apertures k, l, similar to those in the plug
of a stop-cock and which allow free communication between a distributing valve m
_ and the cylinder n of the ram (Figure 1) of the lift or hoist, when the said aper-
tures are situate opposite the two tubular connections d, as is the case when the
movable cylinder is in its lowest position as shewn in the Drawing.
The diameter of the piston i being greater than that of the cylinder h, an annular
space is formed underneath the former which is exposed to the pressure of the water.
The roller-g-carried-by-the-rod-f-of-the-piston supports a lever p. which is
jointed at one end to a fixed bar q, and loaded at the other end with a weight r
calculated according to the length of the lever and the maximum pressure which
the piston is required to resist without rising.
From the foregoing it will be evident that a slight excess of pressure exerted on
the annular piston will cause the cylinder h to rise and with it the apertures k, l,
thus partially or wholly closing the tubular connections d, d, and restraining or
entirely arresting the flow of the water from under the ram cylinder n, and thereby
retarding or suspending the motion of the cage.
It is obvious that this improved apparatus will act not only as a brake in case
of accident, but also as a regulator of the motion when the cage is descending over-
loaded as the excess of pressure will then cause the piston to rise to a certain
extent and with it the cylinder h, thus reducing the sectional area of the channel
for the escape of the water.
Ths counterweight employed for balancing the pressure to which the piston i is
exposed may obviously be replaced by a spring acting upon the piston either
directly or through the intervention of a lever, and the apparatus may be other-
wise modified both in its form and in its details without departing from the
principle of the Invention.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that what I consider to be novel and
original and therefore claim as the Invention secured to me by the herein-before in
part recited Letters Patent is,-
The combination with hydraulic lifts or hoists of an apparatus which is situate
upon the pipe or passage conducting the water from the distributing valve to the
ram cylinder, and is so arranged as to operate automatically after the manner of a
safety valve, in order to regulate or arrest the flow of water from the said cylinder
when the pressure therein exceeds a determined maximum, substantially as herein-
before described.
In witness whereof, I, the said Astley Paston Price, have to this my Specifi-
cation set my hand and seal, this Seventeenth day of April, One thousand
eight hundred and seventy-nine.
ASTLEY PASTON PRICE. (L.S.)