Improvements in and relating to Safety Appliances for the Cages, of Elevators.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to Safety Appliances for the Cages, of
Elevators.
I JOHN ALEXANDER STEVEN, of 12 Royal Crescent. West, in, the. City and
County of Glasgow, Engineer, do hereby declare the nature of my invention to.be
as follows:-,
This invention has reference to improved safety appliances for the cages of
elevators, and whereby in the event of one or more of the hoist ropes breaking,
these.appliances will automatically come into action and. stop the further descent
of the cage.
As applied to a hoist where two ropes are used, these ropes would be attached.
on opposite sides of the centre of a lever, or beam preferably consisting of two
parallel plates set at some distances apart and bolted together but free.to oscillate
on a centre, while if four ropes were used there would be three of such plates..
A link would project some distance up from centre of beam, and have a projecting
head and pulleys at its upper end to guide the ropes. A metal strap would be
passed round the centre pin of lever and pass parallelly down between beams. The
one end of strap would be turned out under the lower flange of carrying beam, while
the other end of strap would project in the opposite direction and extend past
flange, and the lower end of vertical rod would pass through a hole at this outer:
end of strap. The top end of vertical rod would be jointed to the one end of lever,
and part of the rod would be formed with a screw thread round which would be
mounted an adjustable screwed nut. A helical spring would be mounted round the
rod between the bottom of strap and a flange on the 'screwed: nut, and the latter
can be adjusted to give the desired pressure on spring
A lever will be keyed on horizontal shaft which extends the full breadth of cage
supported by three brackets- fixed to carrying beams and on which a safety knife.
is keyed on each end.
One of the parallel plates of main or beam lever to which the hoist ropes are
attached would project out and be formed with a forked or two pronged end; and
should either of the ropes break the beam lever will be tilted and one of these-
forked ends will automatically engage with a 'projection' on the upper arm of the
knife lever and shift the latter into gripping position, with the guides, or should
both ropes break, the helical spring round vertical rod will operate the beam lever
to perform this.functional action..
Dated 16th Decembar 1895
W. R. M. THOMSON & Co.,
96 Buchanan Street, Glasgow, Agenta

page_text: Improvements in and relating to Safety Appliances for the Cages of
Elevators.
I, JOHN ALEXANDER STEVEN, of 12 Royal Crescent, West, in the City and
County of Glasgow, Engineer, do hereby declare the nature of my invention
and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement in writing that is to say:-
-
This invention has reference to improved safety appliances for the cages of
elevators, and whereby in the event of one or more of the hoist ropes breaking
these appliances will automatically come into action and stop the further descent.
of the cage.
And in order that my said invention and the manner of carrying same into
practice may be properly understood, I have hereunto appended a sheet of
explanatory drawings, in which the same reference letters are used to indicate
corresponding parts in the several figures where shown. Figure 1 represents an end
elevation, Figure 2 a side elevation broken away and Figure 3 a plan view in two
broken away parts corresponding to Figure 1 illustrating my improved safety
appliances in connection with the cages of elevators, where four hoist ropes are
used.
Figures 4 and 5 represent detached plan and side elevation views corresponding
to Figures 3 and 2 but where only two hoist ropes are employed.
Referring to these drawings
As applied to a hoist where two ropes are used as shown in Figures 4 and 5 these
ropes a would be attached on opposite sides of the centre of a lever or beam
preferably consisting of two parallel plates A, A, set at some distance apart and
bolted together but free to oscillate on a centre pin A¹ while if four ropes are used
as shown in Figures 1 to 3 there would be three of such plates A.
A link B would project some distance up from centre of beam, and have a
projecting head B₁ and pulleys B at its upper end to guide the ropes a. A metal
strap C would be passed round the centre pin A¹ of lever A. and pass parallelly
down between beams. The one end C¹ of strap C would be turned out under the
lower flange of carrying beam D while the other end C' of strap would project in
the opposite direction and extend past flange, and the lower end of a vertical rod b
would pass through a hole.at this outer end C' of strap. The top end of vertical
rod would be jointed at 6' to the one end of lever A and part of the rod would be
formed with a screw thread at on to which would be mounted an adjustable
screwed nut b³. A helical spring 64 would be mounted round the rod 6 between the
bottom of strap C and a flange on the screwed nut 63, and the latter can be
adjusted to give the desired pressure on spring b.
A lever E is keyed on a horizontal shaft E which extends the full breadth of
cage supported by three brackets F fixed to carrying beams D and on which a
safety knife E' is keyed on each end.
One of the parallel plates A of main or beam lever to which the hoist ropes a
are attached would project out and be formed with a forked or two pronged end A*
and should either of the ropes break the beam lever A will be tilted and one of
these forked ends will automatically engage with a projection on the upper arm of
the knife lever E and shift the knife E into gripping position with the guides, or
should both ropes break the helical spring round vertical rod 6 will operate the
beam lever A to perform this functional action.

page_text: Having now particularly described the nature of my said invention and in what
manner the same is to be performed I declare that what I claim is.
In connection with the cages of elevators the safety appliances which auto-
matically come into action in the event of the hoist ropes breaking, and stop the
further descent of cage, substantially as herein described in reference to and shown
in the accompanying drawings.
Dated the 14th September 1896.
W. R. M. THOMSON & Co.,
96 Buchanan Street, Glasgow, Agents.