Improvements in Safety Appliances for Hydraulic Lifts and Cranes.
Year: 1893

page_text: Date of Application, 1st Aug., 1893-Accepted, 3rd Mar., 1894
COMPLETE SPECIFICATION.
Improvements in Safety Appliances for Hydraulic Lifts and Cranes.
I, FREDERICK GLASS, of Sturt Street, South Melbourne, in the Colony of
Victoria, 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 :-
This invention has been devised to provide complete economical and efficient
safety apparatus for use on elevators or lifts for passengers or goods, and may be
also applied in part to cranes, and provides:-
1st. Gearing which comes automatically into operation with the breakage of the
hauling cables or chains.,
.
2nd. Gearing which comes automatically into operation if the car be over loaded.
3rd. Gearing which comes automatically into operation should one of the pressure
water cylinders or pipes burst.
In order to facilitate an explanation of my invention reference may be made to
the accompanying drawings in which-
Figure 1 shews an elevation of my improved apparatus which is placed on one
or both sides of the car or lift.
Figure 2 being also an elevation shewing an alternative way of arranging some
of the safety gearing.
Figure 3 another elevation shewing my improved gearing together with safety
appliance placed at the bottom of same to provide for the bursting of any of the
pressure water parts.
Figure 4 shews an enlarged view of some of the details of Figure 1.
In these drawings "A" represents the car or lift which is presumably suspended by
ropes passing over overhead sheaves and operated by water cylinders. "B" represents
an ordinary safety can set eccentrically so as to engage, when required, with the
wooden uprights "C." It will be noticed that the action of the cams, so far as
gripping is concerned, is brought about through the medium of weights "D"
balancing the cage "A."
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It should be further explained that the weight or weights "D" are in themselves
only sufficiently heavy to balance the weight of empty car but that additional
weights or weighted levers in any number are provided in connection with
weights "D" as at "F" (Fig. 1). Thus with an empty car, weights "D" are at
rest, and the levers and rods E
E¹" "E" &c. on car are also stationary in
relation to car although car itself be in motion. The end of the lever E' is secured
to a cable G which passes over a jockey pulley Hand down to and under a weighted
pulley D and is returned and finally secured to an eyelet A. If however any
load be placed in car an extra strain is thereby put on the hoisting ropes
"A¹";
is by them transmitted to levers "E2" and through cables "G" to weights "D
causing said weights "D" to rise. The weights or weighted levers "F" however
are so arranged that as weights "D" rise they, through medium of levers or
similar mechanical contrivance, pick up so many of weights or weighted levers "F"
until the strain due to the pull of hoisting ropes on short end of lever "E" is
balanced by the strain on long end of same lever due to the weights "D" plus
added weights "F.”
The weights "F" are of course arranged in proportion to the predetermined load
to be raised or lowered by the lift. It will be seen that as load is put into car the

page_text: strain on hoisting ropes "A" while raising weights "D" and "F" (as already
described) is at same time pulling up rod "E." The weights "" are so propor-
tioned that immediately a weight, above the proper load, is placed in car, the
head "E" of rod "E" which rises as car is loaded, engages with hooked rod "B" "
and pulls cams into gear with guide or upright "C" and locks car in position thus
preventing the very common and dangerous practice of overloading cars and making
lifts carry much heavier weights (especially in descending) than they are designed
to raise.
In Figure the cams * B are actuated either by the falling of a rod "E
below a predetermined point, or by its rising above a predetermined point. In the
first case the head "E" of the rod "E" falls on to and presses the horn "B" of
the cam "B" thus putting it into operation; and in the second case the rising of
the said head "E" beyond the predetermined point, causes an engagement. between
it and a hooked rod 132."
"B" in
It will be noticed that this rod "B" is articulated or hinged in the cam
such a manner that a pull upon it (produced by the upper movement of the
head "E") causes the cam "B" to come into operation and gripping is effected.
In Figure 2 it will be noticed that the cams are worked directly by levers instead
of indirectly as in Figure 1, the reason for which will be hereinafter explained, and
it will be noticed in this figure that the suspension cables are made fast to the
cam "B" at a point producing a short leverage "13" whilst the end of the cam
lever is secured to a cable which latter is passed through a weighted pulley "D"
and up to and over a jockey pulley "H" and is finally attached to the car
any convenient position.
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"
""
" A at
In Figure 3 the arrangement of the weighted cable is somewhat similar but it
will be noticed that the cam "B" is actuated indirectly by an auxiliary arm "J
on which a weight "K" is set. The arm J is actuated by a cable which passes
over jockey pulley and down to and under a weighted pulley D' after which it is
returned and secured to the lift. In this view the weight D is counter-balanced or
supported by a water pressure piston "L" arranged in a cylinder "M." To this
cylinder a pipe "N" communicates with the pressure cylinders or their pipes in
such a manner that should a lift cylinder or pipe or connection burst the pressure
under piston "L" will be removed and the weight "D" will descend and
synchronously operate the cam "B." The mechanism last described may be some-
what similarly applied to hydraulic cranes in which case the parts * .J "K"
and "B" could be attached to a piston rod crosshead (in lieu of the cage "A")
and a parallel runner as "C" Fig. 1 provided for receiving the grip and preventing
the sudden falling of a load in the event of a cylinder or pipe bursting. The
lever R which opens and shuts off the supply of water to the valves is actuated in
the ordinary manner by a cable P which passes over pulleys S. S'.
The modus operandi of my invention is as follows.
Presume that the arrangement shewn on Fig. 1 is in use and that the suspension
cables "A should break. The rod "E" (see Fig. 4) will descend, by reason of
its lever "E" being radiated upwardly; this movement will bring the head "E"
of the rod "E" into pressing contact with the horn "B" on cam "B" with the
result that gripping will immediately follow and descent of the car will be arrested.
Presume that an undue number of people, or weights, are imposed on the car "A."
The lever "E" (Figs. 1 and 4) will lower synchronously with the rising. of the
rod "E" the head "E' will engage with the hook on the articulated rod "N
of "132" and the safety cam "B" will be pulled into gripping position and prevent
any further descent.
"
Referring to Figure 2. Presume the suspension ropes "A" to break. The
pull of the rope at the attachment "B3" would be released and the cable "G"
would pull the cam lever downwards and gripping would follow.
Referring to Figure 3. Presume that a cylinder or water pipe connection were
to burst. The high pressure water in pipe "N" and small cylinder "M" would
immediately lose its energy, the piston "L" would descend and with it the

page_text: weight "D," the cable "O" would become burdened with the weight "D" and an
upward pull would follow ou the auxiliary lever "J" which in its turn would
actuate the cam "B" and gripping would follow.
The weights "D" in Figs. 1 and 2 may fulfil other functions besides balancing
the safety gear, and a glance at Fig. 1 will shew the said weight in connection
with certain valve actuating appliances, the particulars of which have have been
already described and illustrated by me in an application for Patent for such
appliances.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is-
1. In safety appliances for hydraulic lifts-
Special safety cables as "G" (independent of any hoisting ropes or of any
ropes attached to running balance weights for balancing weight of car or of any
speed governor driving ropes) attached to car through medium of pivotted levers
as "Erope drums or pulleys or gearing in such a manner that strain on said
special safety cables is made to counteract strain on hoisting ropes due to loaded
car substantially as and for the purposes set forth.
2. In safety appliances for hydraulic lifts-
Special safety cables as "G" (independent of any hoisting ropes or of any
ropes attached to running balance weights for balancing weight of car or of any
speed governor driving ropes) attached to car through medium of pivotted levers.
as "Erope drums or pulleys or gearing in such a manner that strain on said
special safety cables is made to counteract strain on hoisting ropes due to loaded
car and actuate safety appliances substantially as described.
3. In safety appliances for hydraulic lifts-
The arranging of varying weights or weighted levers (as "F") to counteract the
weight of load in car for purpose of actuating safety gear as described.
4. In safety appliances for hydraulic lifts-
A lever or levers as "E" pivotted on the car itself and arranged to transmit
the strain of hoisting ropes for the purpose of actuating safety gear as described.
5. In safety appliances for hydraulic lifts-
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The combination with a rod as "E" having a head as "E" mounted upon same
with the suspension cables as A" and so arranged that if a breakage of a
suspension cable occurs a weighted lever as "E" will cause the rod "E" to engage
with a cam as "B" substantially as and for the purposes described and in the
manner illustrated.
6. In safety appliances for hydraulic lifts-
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A centred lever as "E" having a short arm linked to a safety cain rod as
and the long arm attached to a cable, said cable being so arranged as to embrace a
weight as "D" substantially as and for the purposes set forth and explained.
7. In safety appliances for hydraulic lifts-
The combination with an articulated rod as "B" and cam as "B," of a rod and
lever as "E" and "E2" respectively substantially as and for the purposes set forth
and described.
8. In safety appliances for hydraulic lifts-
The combination with a cam as "B" to which a suspension cable is attached as
at "B" of an extended arm to which a weighted cable as "G" is secured and
arranged in such a manner that ou the breakage of a suspension cable the extended
arm will radially lower and actuate the cam substantially as and for the purposes
described and as illustrated.
9. In safety appliances for hydraulic lifts and cranes-
A piston as "L" for supporting a weight as "D" and so arranged that when a
cylinder or main water pipe connection bursts the piston "L" will lower and permit
the weight to pull safety gear into operation as and for the purposes herein before
described.

page_text: 10. In safety appliances for hydraulic lifts and cranes-
The combination with an auxiliary lever as "I" the end of which may be
weighted as "K" of a cable as "O" and weight as "D" said weight being
supported by a piston as "L" substantially as and for the purposes hereinhefore set
forth and as illustrated.
11. In safety appliances for hydraulic lifts-
The general arrangement and combination of the parts shewn on Figures 1, 2
and 3 of the drawings constituting improved safety apparatus.
Dated this 31st day of July 1893.
THOMAS PRESCOTT,
53, Arcade Chambers, St. Mary's Gate, Manchester,
Agent for Applicant.