Improvement in Safety Attachment for Elevators.
Year: 1897

page_text: COMPLETE SPECIFICATION.
Improvement in Safety Attachment for Elevators.
I LUCIEN CLAYLON ALCORN, of Greensburg, in the County of Green, and State of
Kentucky, United States of America, Telegraph Operator, 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, reference
being had to the accompanying drawings, and to letters of reference marked thereon
which form a part of this specification :
:-
This invention relates to a stop device for use in connection with elevators, and the
objects in view are to provide means whereby, when the hoisting-cable is broken or
the upward draft upon such cable caused by the weight of the elevator-car is
relieved, the car will be automatically locked and held from downward movement.
Further objects and advantages of the invention will appear in the following
description, and the novel features thereof will be more particularly pointed out in.
the claims.
In the drawings,
Figure 1 is a vertical section of an elevator and the contiguous portion of the well,.
said elevator being provided with stop devices embodying my invention.
Fig. 2 is a similar view showing the stop-pawls in engagement with the
rack-bars.
Fig. 3 is a horizontal section of the line 3 of Fig. 1.
Fig. 4 is a perspective view of the upper portion of the elevator-car and the stop
device carried thereby.
Similar numerals of reference indicate corresponding parts in all the figures of the
drawings.
1 designates a car, which may be of any preferred construction, provided near its
floor and top with laterally-projecting pins 2, arranged in pairs and carrying:
anti-friction cells 3 to bear upon opposite sides of the vertical guides 4, said vertical
guides being attached to vertical timbers 5. and being toothed at their inner
edges to form rack-bars. Rising from the roof or top 6 of the car are standards 7,
which support the rectangular frame 8, having cross-bars 9, and pivotally connected
to the said cross-bars upon opposite sides of their centers are levers 10. The
lower ends of these levers are connected to the inner ends of the pawls 11, fitted
slidably in horizontal guides 12, secured to the upper surface of the roof or top of
the car, and bearing at their outer ends against the lower extremities of the levers
are the actuating-springs 13, which are attached at their inner extremities to a central
stud 14 on the roof or top of the car. The upper ends of the levers are arranged in
radial guide-slots 15 in the horizontal plate 16, which is supported by standards 17
from the above described horizontal frame, said guides communicating at their inner
ends with a central opening 18, through which extends the hoisting-cable 19.
Attached to the lower end of the hoisting-cable and arranged between said levers is
a ball or spreader 20, and when the weight of the car is upon the hoisting-cable
this spreader is drawn upward into contact with the upper surface of the horizontal
plate, which I will, for convenience, term a supporting-plate, the upper ends of the
levers are spread or deflected and are held in contact with the outer ends of the
radial guide-slots. This disposition of the levers causes the pawls to maintain a
position out of contact with the teeth of the rack-bars, and therefore the car is free to.
move vertically. When, however, the cable breaks or is allowed to run out by reason.

page_text: of injury to the elevating mechanism, the spreader drops from its position in contact
with the supporting-plate, and by allowing the upper ends of the levers to approach
each other causes the outward movement of the pawls, and hence the engagement
thereof with the rock-bars, thus checking the downward movement of the car.
The spreader preferably consists of a polished metallic sphere, and as the levers
occupy an inclined position when separated or spread at their upper ends it will be
seen that upon relieving the strain on the hoisting-cable the inward pressure of
the levers, due to their actuating springs, will force the spreader downward and
thus allow the engagement of the pawls with the rack.
From the above description it will be seen that the device is simple in construction
and may be manufactured at a comparatively small cost, and that the slacking of the
hoisting-cable cannot fail to result in the immediate operation of the locking-pawls.
Various changes in the form, proportion, and the minor details of construction may be
resorted to without departing from the principle or sacrificing any of the advantages
of this invention.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
'I claim is :-
1. The combination with rack-bars arranged parallel with the path of an elevator
car, of spring actuated pawls disposed in operative position with the rack-bars,
intermediately pivoted levers connected at one end respectively to the pawls and
converging toward their other ends, a supporting-plate provided with radiating
guide-slots for the free ends of the levers, said slots communicating with a central
opening, a hoisting-cable extending through said opening in the supporting-plate and
a spreader attached to the end of the cable and arranged between the upper ends of
the levers, whereby when the hoisting cable is strained said spreader is brought
into contact with the supporting-plate and separates the contiguous ends of the levers,
substantially as specified.
2. The combination with rack-bars arranged parallel with the path of an elevator-
car, of spring actuated pawls arranged in operative relation with the rack-bars,
intermediately pivoted levers connected at one end respectively to the pawls and
converging toward their opposite ends, a supporting-plate having radiating guide-
slots for the free ends of the levers, and a polished spherical spreader attached to a
hoisting-cable and disposed between the convergent upper portions of the lever,
substantially as specified.
Dated this 26th day of January 1897
J. P. BAYLY,
18 Fulham Place, W., Agent for Applicant.