Improvements in or connected with Raising and Lowering Apparatus for Mines and the like.
Year: 1899

page_text: Date of Application, 22nd Aug., 1899
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Date of Application, 22nd Aug., 1899
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PROVISIONAL SPECIFICATION.
Improvements in or connected with Raising and Lowering Apparatus
for Mines and the like.
I, DAVID DAVY, of Broomcroft, Parkhead, near Sheffield, in the County of
York, Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to an improved system of raising and lowering cages in
coal mines and the like. in connection with which application for Letters Patent
was filed by me on the 5th day of December 1898 No. 25649; and wherein a
series of cages are slung between a pair of endless chains which pass around
pairs of pulleys at top and bottom of the shaft and, being caused to travel
continuously in one direction, effect the raising and lowering of the cages con-
currently with the upward and downward movement of the opposite sides of the
endless chains.
The object of my present invention is to relieve the endless chains as far as
possible of the strain due to their own weight and that of the cages, and also
to relieve the upper pulleys (over which the chains pass and upon which they
are suspended) of the greater part of the total weight of the chains, cages, etc.
To this end the total weight is in effect subdivided and each portion thereof
is independently sustained as follows:-The chains are supported at intervals
throughout the depth of the shaft by being made to gear with pairs of sprocket
pulley's mounted to rotate freely, each on an axis fixed to a frame supported by
springs or balance weights. Each pulley is of a diameter corresponding to the
distance apart of the ascending and descending side of the chain in whose plane
the pulley revolves so as to gear with both sides of the chain simultaneously,
and the supporting springs or balance weights are made sufficiently powerful to
sustain the weight of the ascending and descending portions of the chain com-
prised between the pulley which they support and the next lower support,
together with the weight of the included cages and their contents, so that
instead of successive lengths of chain, counting from below upwards, having to
support increased loads, each section of chain (comprised between two adjacent
pairs of supporting pulleys) has to support the weight of that section alone,
together with the weight of the included cages.
Each of the frames is free to rise and fall within the limits of the tension of
the supporting springs, and is guided in such vertical movement, and at same
time caused to maintain the pulley in the plane of the chain, by means of suit-
able guides carried by girders fixed to the sides of the shaft, the supporting
springs being interposed between the frame and the girders so as to be put
either in tension or compression by the load, as may be preferred. Fixed guides
serve to maintain the ascending and descending sides of the chain in gear with
the pulley.
Instead of a single pair of pulleys being used in each section to gear with, and
support, both the ascending and descending sides of the chain simultaneously,
as above described, I might employ two separate pairs of pulleys for the same

page_text: purpose, such pulleys being placed outside instead of between the ascending and
descending chains and geared together by any suitable means.
Dated this 22nd day of August 1899.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
Improvements in or connected with Raising and Lowering Apparatus
for Mines and the like.
I, DAVID DAVY, of Broomcroft, Parkhead, near Sheffield, in the County of
York, Engineer, 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:-
My invention relates to endless chain elevators for raising and lowering
generally and particularly to the apparatus of this class, for which Letters Patent
were granted to me dated 5th December 1898 No. 25,649.
The object of my present invention is to relieve the endless chains (and the
upper pulleys over which they pass) of the permanent load constituted by the
aggregate weight of the pendant chain and the aggregate weight of the attached
cages, without regard to the temporary load due to the weight of the contents
of the cages.
To this end the total weight of the chains and cages is in effect subdivided so
that the chains being supposed to be divided into independently supported sections
each such section will sustain as a permanent load only its own weight and that
of the cages suspended therefrom. To this end the chains are supported at
intervals by being made to gear with intermediate sprocket pulleys mounted to
rotate freely each on an axis movable and guided in the vertical direction and
supported by springs or counter-balanced, the oppositely movable members of
each chain gearing either with opposite sides of the same pulley, or with different
pulleys geared together so that in either case the oppositely movable members of
each section balance each other at, and are supported by, the said intermediate
pulley or pulleys. Instead therefore of the chains having to sustain at the upper
part the cumulative strain due to the aggregate permanent load, each section of
chain (for the time being) has to support as a permanent load only its own
weight and that of the cages carried by it.
Reference is to be had to the accompanying drawings forming part of this
Specification wherein Figure 1 is a general view illustrating my present invention
as applied to the endless chain system of elevator for which my previous Letters
Patent were granted. Figure 2 is a face view and Figure 3 an edge view of
one of the chain supporting pulleys when applied as indicated in Figure 1 between
the ascending and descending members of the chain. Figure 4 is an edge view
of a similarly applied pulley supported by hydraulic pressure instead of by
springs. Figure 5 is an elevation and Figure 6 a plan showing the ascending
and descending members of the chains as supported by different pulleys coupled
together by chain gearing.
The same letters of reference denote like parts in the several figures.
In Figure 1 (which illustrates the application of my present invention to the
system of elevator for which my former Patent was granted) A A indicates a
pair of continuously travelling endless chains which pass over pairs of
pulleys B, D, at top and bottom of the shaft, and between which chains, the

page_text: cages C are suspended from cross bars A¹ (Figure 6) by links E E¹ (Figure 1),
the chains being guided by pulleys H and the cage suspension links being guided
by guides L, L, I, J, K at top and by guides M N at bottom of the shaft in
such manner that the cages are brought to positions of rest for loading and
unloading, whilst the chains continue to travel around the pulleys at the top
and bottom of the shaft, all as described in the Specification of my former l'atent
aforesaid.
At suitable intervals in the depth of the shaft are mounted intermediate
sprocket pulleys O, each pulley gearing with both the ascending and descending
members of a chain as shown in Figures 1 and 2, the arrangement being similar
for both the chains of the elevator. Or instead of the same intermediate pulley
gearing directly with both members of the chain, separate pulleys may gear with
the two members and be geared together as illustrated in the Figures 5 and 6.
In Figures 1 and 2 the intermediate sprocket pulley O is mounted between and
gears at opposite points of its diameter with, the ascending and descending
members of the endless chain there being for the two chains A, at each point
of intermediate support, two pulleys in axial alignment, the pulleys being in-
dependently and similarly supported. Or the pulleys might be mounted on the
same transverse shaft (provided there is sufficient clearance between the ascending
and descending cages) the shaft being similarly supported at its two ends, but
separately supported pulleys are preferred.
In the example illustrated each pulley is journalled in a frame P provided at
top and bottom with vertical guide rods working in guides carried by girders Q
fixed to the sides of the shaft, springs R (adapted to act by compression, or by
tension as the case may be) being interposed between the frame or its guide
rods and the girders so as to support the permanent load brought on the pulley ()
by the oppositely moving members of the chain in gear with said pulley. The
chains are held in gear with the pulleys by fixed guides S and are provided with
small pulleys at the joints which roll against the guides S and facilitate the
entry of the chains into gear with the sprockets.
Instead of springs counter-balance weights might be applied to act on the
frames P in which the pulleys are mounted through the medium of levers mounted
on fixed points of support or through chains passing over guide pulleys as will
be readily understood.
In Figure 4 a hydraulic cushion is shown formed of a ram on the frame working
in a hydraulic cylinder T in connection with a pipe t connected to an accumulator
or rising to a sufficient height to afford the necessary head of water in order that
the hydraulic pressure acting against the ram shall counter-balance the permanent
load on the pulley.
0
In Figures 5 and 6 a pulley O gears with the ascending member of the chain A,
and a similar pulley 01 gears with the descending member, each pulley being
mounted and supported on cushions as above described and each pulley Ŏ being
geared with its fellow pulley 01 acting on the other member of the same chain
by an endless chain U running on sprocket wheels V, VI fast on the axles of
the pulleys 0 0 so that the two pulleys 0 0¹ will in effect act to sustain the
members of chain pendant therefrom in the same way as the single pulley before
described. A similar arrangement of pulleys is provided for each of the chains A.
In every case the strength of the springs or the weight or pressure of the
counter-balancing medium should be as nearly as possible sufficient to support
the permanent load due to the weight of the chain sections and of the attached
cages, without regard to the temporary load due to the weight of the contents of
the cages.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. The combination with endless chain elevators, of intermediate sunporting

page_text: pulleys spring lifted or counter-balanced as described, each such pulley being in
gear at its opposite sides with the oppositely movable members of the endless
chains so that the permanent loads of the two members of the chain (so far as
said members are pendant from the pulley) and of the attached cages will
counter-balance each other at, and be sustained by, said pulley and its support as
and for the purpose described.
2. The combination with endless chain elevators, of intermediate supporting
pulleys spring lifted or counter-balanced as described, each such pulley being in
gear with one member of one of the endless chains and being geared with a
similar pulley geared with the other member of the same chain so that the
permanent loads of the two members of the chain (so far as said members are
pendent from the pulleys) and of their attached cages will counter-balance each
other at, and be sustained by, said pulleys and their supports as and for the
purpose specified.
11... LM 1000
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.