IMPROVEMENTS IN HYDRAULIC LIFTS
Year: 1885

page_text: We HENRY CLAUDE WALKER, and ROBERT CAREY, both of Falmouth Road,
in the County of Surrey, Engineers do hereby declare the nature of our invention
for "IMPROVEMENTS IN HYDRAULIC LIFTS" to be as follows:-
Our invention relates to hydraulic lifts or hoists, in which a cage or other
weight to be lifted is raised by means of a ram working in a cylinder to which
water under pressure is admitted for the purpose of raising the cage or other
weight, the pressure being removed or reduced when it is required that the cage
or weight shall descend.
In such bydraulic lifts or hoists especially when the range or stroke of the lift
is great, the length and effective weight of the ram protruding from the cylinder
increases considerably as the weight is raised, and decreases as it is lowered, and
it is found desirable, in order that uniformity and evenness of movement should
be obtained, that the weight of such protruding part of the ram should be balanced
by a weight varying in about the same relative proportion as that of the ram, and
our present invention has for its object a novel method of so providing a varying
balance weight or weights for the purpose described, and also for the purpose of
balancing the varying pressure upon the lifting ram caused by the varying height
of the head of water upon the larger ram or piston by which the lifting ram is
actuated in the well known way.
Supposing that our invention is to be applied to a bydraulic lift in which the
cylinder containing the lifting ram is in connection with a second cylinder
containing a ram loaded with a sufficiently heavy weight to balance or nearly
balance the weight of the lifting ram and cage in the usual well known way, we
connect to the upper part of such loaded ram the upper ends of one or more
flexible chains, ropes, or bands, which are then carried down to a sufficient distance
and passed under fixed pulleys or drums, and are thence carried again up and
attached to the circumference of corresponding pulleys or drums fixed upon a
shaft revolving in bearings fixed. to any convenient support. Upon the same
shaft we fix a drum the circumference of which is not cylindrical, but spiral or
of gradually increasing radius, and to this spiral drum at its largest radius we fix
the end of a flexible chain, rope, or band the lower end of which carries a weight
of sufficient size, so that as the shaft and spiral drum revolve, the chain is coiled
upon the latter, and lifts the weight which acts with a constantly decreasing
leverage as the effective radius of the drum on which it is coiled decreases.

page_text: Supposing the lifting ram and cage to be at the bottom of their stroke, the
loaded ram being at the top of its stroke, and the spiral drum consequently in the
position in which the chain or rope is coiled upon it and the weight at the top of
its stroke and acting upon the shortest radius of the spiral, it is evident that in
this position the weight is exerting its least effect in aiding the weight of the
loaded ram in balancing or nearly balancing the lifting ram and cage, the former
of which is completely within its cylinder.
If now bydraulic pressure be applied to the loaded ram in any of the usual well
understood ways for the purpose of forcing it down and raising the lifting ram
and cage, then as the lifting ram protrudes from its cylinder the varying length
of its protruding part requires to be balanced in a manner varying to a corre-
sponding degree, and the chain or rope uncoils from the spiral drum and acting
upon a radius of constantly increasing length, has a similarly increasing effect in
aiding the weight of the loaded ram, and the latter consequently acts with a
gradually increasing force upon the lifting ram as the latter protrudes from its
cylinder until it has reached the top of its stroke; and the weight and proportions
of the spiral drum can be easily so arranged that the action of the loaded ram
upon the lifting ram remains practically the same through the full length of the
stroke of the latter.
Instead of one spiral drum, chain or cord, and weight, two or more may be used
of proper proportional size and weight.
In forms of bydraulic lift in which the loaded ram or its equivalent operates
upward or in any other direction instead of downward, the chains, cords or bands
are connected with pulleys in the proper positions, the spiral drum or drums and
balance weights being used in the same way as already described, and where
balance chains and weights are used to balance the lift and cage, the varying
effective weight of such chains may be balanced in the same way; or the varying
effective weight of the loaded ram itself may be similarly balanced.
Instead of a spiral drum or drums as described we sometimes arrange a series of
small weights at intervals one above the other round the balance chain or rope.
These small weights rest upon supports at regular intervals above one another,
in such manner that they are taken up in succession and so progressively increase
the weight upon the chain as the latter rises, whilst they are deposited one after
another upon their supports and so lessen the weight upon the chain as it descends,
the required varying balance being thus obtained.
Our invention is equally applicable to hydraulic lifts where the ram instead of
being loaded with weights is forced down by hydraulic pressure.
It will be seen that in our invention we use no levers or joints of any kind
whatever, but that the variable balancing force required is obtained solely bý
means of weights suspended to chains, cords, or bands, passing round spiral drums.
Dated this 29th day of January 1885.

page_text: We, HENRY CLAUDE WALKER, and ROBERT CAREY, both of Falmouth Road, in
the County of Surrey, Engineers, 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 and accompanying Drawing (that
is to say):-
Our invention relates to that form of hydraulic lifts or hoists, in which a cage
or other weight to be lifted is raised by means of a ram working in a cylinder to
which water under pressure is admitted for the purpose of raising the cage or other
weight, the pressure being removed or reduced when it is required that the cage
or weight shall descend.
In such hydraulic lifts or hoists, especially when the range or stroke of the lift
is great, the length and effective weight of the lifting ram protruding from the
cylinder increases considerably as the weight is raised, and decreases as it is
lowered, and it is found desirable, in order that uniformity and evenness of
movement should be obtained, that the weight of such protruding part of the rain
should be balanced by a weight varying in about the same relative proportion as
that of the rain, and our present invention has for its object a novel method of so
providing a varying balance weight or weights for the purpose described, and also
for the purpose of balancing the varying pressure upon the lifting ram caused by
the varying height of the head of water upon the larger ram or piston by which
the lifting ram is actuated in the well known way.
In the accompanying drawing, which is in illustration of our invention, figure 1
shews its application to a hydraulic lift in which the cylinder a (shewn broken off)
containing the lifting ram b is in connection with a second cylinder c containing a
ram d loaded with a weight e sufficiently heavy to balance or nearly balance the
weight of the lifting ram a and cage f, in the usual well known way. We connect
to the upper part of such loaded ram d at h the upper ends of one or more flexible
chains, ropes, or bands, g, g, which are then carried down to a sufficient distance
and passed under fixed pulleys or drums i, i, i, and are thence carried again up and
attached to the circumference of corresponding pulleys or drums k, l, fixed upon a
shaft revolving in bearings fixed to any convenient support. Upon the same
shaft we fix a drum m the circumference of which is not cylindrical, but spiral
or of gradually increasing radius, (as shewn in side view in figure 2), and to this
spiral drum at its longest radius we fix the end of a flexible chain, rope, or band n
the lower end of which carries a weight o of sufficient size, so that as the shaft
and spiral drum m revolve, the chain n is coiled upon the drum m, and lifts the
weight o which acts with a constantly decreasing leverage as the effective radius of
the spiral drum m on which it is coiled decreases.
Supposing the lifting ram b and cage f to be at the bottom of their stroke, the
loaded ram d being at the top of its stroke, and the spiral drum m consequently in
the position in which the chain or rope n is coiled upon it and the weight o at the
top of its stroke and acting upon the shortest radius of the spiral m, it is evident
that in this position the weight o is exerting its least effect in aiding the weight
of the loaded ram d in balancing or nearly balancing the lifting ram b and cage f
the former of which is completely within its cylinder a (such position being the
opposite end of the stroke to that shewn in the drawing).

page_text: If now hydraulic pressure be applied to the loaded ram d in any of the usual
well understood ways for the purpose of forcing it down and raising the lifting
ram b and cage f, then as the lifting ram 6 protrudes from its cylinder a and
the varying length of its protruding part requires to be balanced in a manner
varying to a corresponding degree, the chain or rope n uncoils from the spiral drum
and acting upon a radius of constantly increasing length, has a similarly increasing
effect in aiding the weight of the loaded ram d, and the latter consequently acts
with a gradually increasing force upon the lifting ram bas the latter protrudes
from its cylinder until it has reached the top of its stroke (as shewn in the
drawing), and the weight o and proportions of the spiral drum m can be easily so
arranged that the action of the loaded ram d upon the lifting ram b remains
practically the same through the full length of the stroke of the latter.
Instead of one spiral drum, chain or cord, and weight, two or more may be used
of proper proportional size and weight.
In forms of hydraulic lifts in which the loaded ram or its equivalent operates
upward or in any other direction instead of downward, the chains cords or bands
are connected with pulleys in the proper positions, the spiral drum or drums and
balance weights being used in the same way as already described, and where
balance chains and weights are used to balance the lift and cage, the varying
effective weight of such chains may be balanced in the same way (as shewn in side
view in figure 3, and in plan in figure 4), in which the case f and the lifting ram b
are shewn balanced by one or more weights p attached to a chain or rope passing
over a pulleys upon a shaft t, upon which shaft is fixed the spiral drum or
pulley m round which is coiled the chain or rope n carrying the balance weight o,
the effective weight of which consequently varies with the varying weight of the
protruding ram b which is to be balanced as in the arrangement first described.
Or the varying effective weight of the loaded ram e itself may be similarly
balanced.
Instead of a spiral drum as described we sometimes arrange a series of small
weights at intervals one above the other round the balance chain or rope. These
small weights rest upon supports at regular intervals above one another, in such
manner that they are taken up in succession and so increase the weight upon the
chain as the latter rises, whilst they are deposited one after another upon their
supports and so lessen the weight upon the chain as it descends, the required
varying balance being thus obtained.
Our invention is equally applicable to hydraulic lifts where the ram instead of
being loaded with weights is forced down by bydraulic pressure.
It will be seen that in our invention we use no levers or joints of any kind
whatever, but that the variable balancing force required is obtained solely by
means of weights suspended to chains, cords, or bands, passing round suitable drums
.or pullies.
Having now particularly described, and ascertained the nature of our said
Invention, and in what manner the same is to be performed, we declare that what
we claim is
In hydraulic lifts, the methods of varying the effective weight of the balance
weight, or weights, substantially as described and shewn in the drawing.
Dated this 29th day of October 1885.
EDWARDS & Co.,
Agents for the Patentees,
35, Southampton Buildings, London.