Improvements in Safety Appliances for Lifts, Hoists, and the like.
Year: 1889

page_text: Date of Application, 6th Feb., 1889
Complete Specification Left, 5th Nov., 1889-Accepted, 7th Dec., 1889
PROVISIONAL SPECIFICATION.
Improvements in Safety Appliances for Lifts, Hoists, and the like.
I, ROBERT MIDDLETON, of Sheepscar Foundry, Leeds, in the County of York,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has reference to a mode of actuating or putting into action Safety-
Catches attached to the cages, especially to such as work with one or more balance
weights, or their equivalents.
It consists in having a special extra rope, (which follows the cage up and down)
attached to the main balance weights wholly or in part, as may be required; but
which, in case the main balance weights, or their equivalents, give way, produces a
pull or strain such as throws the safety clutches into action. This rope which I
term the "Safety-rope" also performs another duty, riz. it causes an arin mounted
on a shaft, round which it is led on a rope-pulley, to revolve so that when any dangerous
speed is reached a portion of the revolving arm flies out and releases a catch. This
catch either brings the gripping devices into action or sets a brake to work on the main
shaft, or performs any other act calculated to bring the cage to a standstill.
The object of my invention is (1) to simplify the mechanism and increase the
efficiency of safety catches; and (2) especially to add to the usefulness of my gripping
wedges referred to in my Complete Specification, No. 15,292-1887.
I carry out my invention as follows:-supposing my gripping wedges are to he
used, I fix these to the cages and arrange their actuating levers on the cage roof. In
connection with these latter is the "Safety-rope' so attached to them-directly
or indirectly that when firmly pulled the wedges are put into action.
The "Safety-rope" need have nothing to do directly with the main balancing
of the cage, but it must be directly or indirectly connected to the main balance
weights, if it is desired to get the fullest advantages.
""
The Safety-rope is led upwards to the overliend beams, and then downwards
after being taken over one or moro pullies.
Attached to its end are by preference one or more smaller counterweights whose
dnty it is to keep the rope tight and consequently in good contact with the last
mentioned pullies-some portion of these smaller weights being borne by the main
balanco-weights. On the shaft of one of these pullies is fixed (1) a wheel capable of
retaining any catch that may be dropped or thrust into it, and (2) an arm or lever
on which a weight is arranged to slide. This weight is held in mid position on the
arm by one or more springs.
The arm and its weight necessarily revolve whenever the cage moves, by reason
of the "Safety-rope" being led over it, i.e. over what may be termed the "", speed-
regulating-pulley. At ordinary speeds the weight on the arm occupies a position
which clears an adjacent tappet, but at a given extra speed it flies out far enough to
strike this tappet which then disengages a catch, or other gear, which locks and fixes
the speed-regulating-pulley (and the rope in like manner, if desired, directly). This
locking of the pulley in the case of a descending cage-necessarily produces an
additional pull at that end of the "Safety-rope" which is attached to the levers and
the gripping wedges are thus pulled into action.
33
The pull from the small counterweight on the "Safety-rope or from the main
balance weight must not be able to draw the wedges into gear, either in ordinary
running, or in stopping or starting. In cases in which it is desired to release a brake,
to act on the main shaft of the hoist-gearing, the trigger gear which locks the "speed-
regulating pulley" may be used for this purpose.
Where it is thought desirable a suitable portion of the weight attached at the
end of the Safety-rope may be borne by the main balance weights of the cage.
t
"

page_text: (or by their terminal connections,) so that in case of one or both of these breaking a
heavier balanco-pull, or jerk, would be immediately given and passed forward to the
gripping wedges.
In cases where other gripping devices are used the pull from my "Safety-rope
would be applied directly or indirectly to the part best adapted to receive it.
In certain cases the Safety-rope may be applied to cages &c., where there are no
main halance-weights,
It must be understood that the "Safety-rope" may be directly coupled to the
main-counterweight of the cage, but the better plan is to so couple it that should
the main balanceweight fall it leaves a suitable portion of the weight attached to the
61 Safety-rope, which then not only jerks the wedges up hat holds them up until they
bite supposing that they had not done so at the first jerk.
Dated this 5th day of Fabeuary 1880.
WM. SNOWDON,
9, Beckett's Bank Chambers, Leeds, Yorks., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Safety Appliances for Lifts, Hoists, and the like.
I, ROBERT MIDDLETOS, of Sheepsear Foundry, Leeds, in the County of York,
Engineer, do hereby declare the nature of this invention and in what manner the
same is to ho performed, to be particularly described and ascertained in and by the
following statement :—
This invention has reference to a mode of actuating or pulling into action
Safety Catches nitnched to the cages, especially to such as work with one or more
halance weights, or their equivalents.
It consists in having a speial extra rope, (which follows the cage up and down)
attached to the main balanes weights, wholly or in part, as may be required; but
which, in ease the main balance weights, or their equivalents, give way, produces a
pull or strain such as throws the safety clutches into action. This rope which 1 term
the "
Safety-rope also performs another duty, it causes an arm mounted on a
simft, round which it is lel on a rope-pulley, to revolve, so that when any dangerous
speed is reached a portion of the revolving arm flies out and releases a catch. This
cateh either brings the gripping devices into action or sets a brake to work on the
main shaft, or performs any other act calculated to lessen the speed or bring the
rage to a standstill.
The object of my invention is (1) to simplify the mechanism and increase the
efficiency of safety catches; and (2) especially to all to the usefulness of my gripping
wedges referred to in my Patent No. 15292 of 1887.
I carry out my invention as follows:-and in order to fully explain my meaning I
havo annexed two sheets of drawings; Fig. 1 is a front elevation-partly in section―
and fig. 2 is a corresponding side elevation, for the purpose of illustrating how my
invention may he carried into effect. The same letters refer to the same parts in
hoth the figures.
Suppose my gripping wedges to be used. I fix these to the cages-soe A A, fig. 1,
and arrange their actuating levers B, B, fig. 2 on the cage roof. "In connection with
these latter is the "Safety-ropa" (, so attached to them, directly, or indirectly, that
when firmly pulled the wedges are put into action. Here the rope is connected
by the ropes C, C', to each of the levers B which have a common fulcrum at B':
hence if the "Safety-rope" be pulled the wedges will be at once drawn up
into action.
The "Safety-rope" need have nothing to do directly with the main balancing
of the cage, but it must be directly or indirectly connected to the main balance
weights, if it is desired to get the fullost advantages.
The "Safety-rope" is led upwards from the cage to the overhead loams, and then
downwards, after being taken over one or more pullies D. & E.

page_text: Attached to its end are by preference one or more smaller counterweights F&F'
whose duty it is to keep the rope tight and consequently in good contact with the
last mentioned pullies-some portion of these smaller weights being borne by the
main balance weight or weights F². On the shaft of the pulley, D, is fixed (1) a
wheel G capable of retaining any catch that may be dropped or thrust into it; and
(2) an arm or lever H on which a weight I is arranged to slide. The weight is held
in mid position on the arm by one or more springs.
Here the cross-arm H carries two weights-one to counterbalance the other, the
movable one, J (which is shown in section) being held in its ordinary working
position by two nuts which may be used for adjusting both its position and the amount
of compression on the internal spring K.
if
The arm and its weight necessarily revolve whenever the cage moves, by reason
of the Safety-rope" being led over what may be termed the "speed regulating-
pulley D." At ordinary speeds the weight on the arm occupies a position which
clears an adjacent tappet L, as shown by the dotted line, but at a given extra
speed it flies out far enough to strike this tappet which then disengages a catch, or
other gear, which locks and fixes the speed regulating-pulley (and the rope in like
manner, if desired, directly or indirectly).
Hero the tappet L is shown fixed on a shaft L' which also carries the locking catch
lever L². This latter would be free to fall into the indentations in the wheel G
were it not that a pin, formed of, say, small copper wire (see L³) holds it up. A very
light blows shears this pin and liberates the locking catch which then seizes the wheel.
This locking of the pulley-in case of a descending cage-necessarily produces an
additional pull at that end of the "Safety-rope" C which is attached to the lovers B,
and the gripping wedges A are thus pulled up into action.
The pull from the small counterweight on the " Safety-rope," or from the main
balance weight, must not be able to draw the wedges into gear, either in ordinary
running, or in stopping or starting.
In cases in which it is desired to release a brake, to act on the main shaft of
the hoist-gearing as shown on the drawings of Patent 15,292 of 1887-the gear
which locks the "speed-regulating-pulley may be used for this purpose.
Or other independent tappets or catches may be arranged to bring about other
desirable results; for instance M is a tappet (say pinned in position) which is fixed on
the shaft M on this same shaft is fixed a lever N whose end, N¹, supports a tail
lever O, mounted on the shaft O'. A locking catch lever O is likewise mounted on
the shaft O' and this when released falls between stops P P &c. arranged round the
side of a pulley used for carrying the main ropes of the hoist. Hence if a dangerous
speed is reached the main pullies and their shaft may be locked and that inde-
pendently of the Safety-rope's action. Such a catch could be thrown in at a less
speed than that required to actuate the gripping clutches. Where it is thought
desirable a suitable portion of the weight attached at the end of the "Safety-rope
may be borne by the main balance weight or weights of the cage, (or by their
terminal connections) so that in case of one or both of these main ropes breaking a
heavier balance-pull, or jerk would be immediately given and passed forward to
the gripping wedges.
6.
17
22
In fig. 1 the small balance weight F is made of a weight such as will keep the
Safety-rope tight. The main ropes of the cage are attached to the main balance
weight F. This (F) supports another weight, F', which latter, if the former, F",
fall, suspends itself on the weight F (see the suspending pin) and its extra weight
gives a very decided pull (with a continuous extra strain) to the "Safety-rope."
In cases where other gripping devices are used the pull from my
"Safety-rope
would be applied directly or indirectly to the part best adapted to receive it."
In certain cases the Safety-rope" may be applied to cages &c. where there
are no main balance weights, i.e. so far as the keeping of the speed down to its
proper limit is concerned. This either by releasing gripping catches or by stopping
or neutralizing the driving power,

page_text: It must be understood that the "Safety-rope," may be directly coupled to the
main counterweight of the cage, but the better plan is to so couple it it should
the main balance weight fall it leaves a suitable portion of the weight attached to
the "Safety-rope," which then not only jerks the wedges up
but holds them up until
they bitesupposing that they had not done so at the first jerk-as last described.
The "Safety-rope and the main ropes are shown broken on the balance-weight
side, so as to allow the latter to be introduced into the drawing.
"
X. X. represents the cage shown broken to save room, and Y. Y. are the main
supporting pullies mounted on their shaft Z which may run in any suitable bearings
-not shown.
Having now particularly described and ascertained the nature of my said inven-
tion and in wint manner the same is to be performed I declare that what I
claim is :-
1. The of a special extra safety-rope or ropes attached to the main balance
weight, or its equivalent, carried over one or more pullies at the head of a hoist and
connected with, and arranged to nettate, gripping elutehes, or other such devices,
in connection with the cage in case the main rope or ropes give way, substantially
as, or after the manner described and shown.
2. The use of a perial extra safety-rop or ropes preferably attached to the main
halaner weight, where such is used, or its equivalent, carried over one or more pullies
so as to actuate them and cause a gripping device, brake, or locking arrangement
to be put into action whenever an excessive speel is attained, substantially us, or
after the manner described and shown.
3. The use of a safety-rope when arranged to combine the double work, namely,
(1) liberating the gripping clutches connected with the cage if the main rope breaks,
and (2) actuating other such devices, breakes, or locking arms in case too great a spreid
is reached, substantially as, or after the manner described and shown.
1. The combination of parts forming the safety-geve which nets it the main rope
or ropes give way, st Istantially as, or after the manner described and shown.
5. The combination of parts forming the gear for releasing locking catches, brakes,
and the like, substantially as, or after the manner described and shown.
Dated this 4th day of November 1889.
WM. SNOWDON,
9, Beckett'» Bank ('hambers, Leeds, Yorks., Agent for the Applicant,