Improvements in or relating to Safety Lifts, Hoists, and the like.
Year: 1897

page_text: Date of Application, 29th Dec., 1897-Accepted, 26th Feb., 1898
COMPLETE SPECIFICATION.
Improvements in or relating to Safety Lifts, Hoists, and the like.
I, HEINRICH BAUM, of Dudweiler, in the District of Saarbrücken, Germany,
Locksmith, do hereby declare the nature of my said 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 safety lifts, hoists and the like; and its object is to fit
the same with improved appliances for preventing the fall of the cage in case of
breakage of the hoisting chains or ropes.
According to my invention I fit the lift shaft with two vertical gripping beams,
on opposite sides of the shaft; and I fit the cage with pivoted levers having eccen-
trically formed gripping faces. These levers are fitted with suitable springs
whereby their gripping faces are caused to grip the vertical beams and arrest the
motion of the cage on the breaking of the hoisting chain or rope.
And in order that my said invention may be particularly described and ascer-
tained, reference is hereby made to the accompanying drawings, in which similar
letters of reference indicate corresponding parts, and in which the application of
my invention to lifts is illustrated.
Figs. 1 and 2 are elevations of the lift cage at right angles to each other.
Fig. 3 is a detail view showing the positions assumed by the levers after the
breaking of the hoisting chain.
Fig. 4 illustrates the method of forming the gripping faces of the levers.
a a are the lower end and cross head of the hoisting rod or piston bb bb are
chains attached to the cross head by steel bolts r. i is a spring to reduce concussion
on sudden stoppage of the cage. The lower ends of the chains are linked to the
long arms of the upper levers c, as shewn. The levers c, c1, c2, are pivoted to the
cage at t. The short arms of the same levers are formed eccentrically with respect
to the centres t on which they work. Each of the series of levers is linked together
by screw rods and unions 9, with right and left hand screw threads arranged so as
to secure parallelism and simultaneity of action. The gripping faces of the levers
are (preferably) formed with teeth, as shown enlarged in Fig. 4, in order to effect
a secure gripping of the beam k. ff are springs which press downwards the long
arms of the levers on the breaking of the hoisting chain or other gear. 2 are
slots in the levers c¹ and 3, in which the ends of four bars are fitted. These bars
are covered with or carry plates u, which may be fitted with rails w, or other
suitable appliances. The weight of the cage and its contents assist in securing
the effectual grippling of the levers, when in action.
Assuming that the apparatus is in the position shown in Figs. 1 and 2, and
the cage is being lifted, the long arms of the levers c¹ care simultaneously raised
with those of the levers e, and the whole of the gripping faces are thereby retained
out of contact with the fixed beams k, and the lift is free to travel. The levers are
prevented from rising too far by the stops xx.
In order to further assist in securing regularity of action, rods e are fitted to the
levers c, serving also as distance rods to the levers c, c.
In case the lifting chain should break the springs f immediately act and press
down the long ends of the levers c¹² and with them the levers c. This causes the

page_text: whole of the eccentrically formed gripping faces to grip the surface of k, as shown
in Fig. 3; the weight of the lift, cars and goods also assisting in increasing the
intensity of the grip, and securing the cage against falling.
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 improvements in or relating to safety lifts, hoists, and the like, substan-
tially as and for the purposes described.
2. In apparatus for safety lifts, hoists, and the like, the combination of lever
arms cc, pivoted to the cage and fitted with springs f; the levers having short
arms formed with eccentrically shaped gripping faces; the long arms of the levers
being linked together by adjustable links g to ensure parallel action; transverse
bars and e and gripping beams k; the cage being sustained by the rod or piston a
and chains b, all so operating that, on the breaking of the chain or rope the gripping
faces of the levers grip the beams and arrest the downward motion of the cage,
substantially as herein before described and illustrated by the drawings.
Dated 29th December 1897.
GEORGE DOWNING & SONS,
8, Quality Court, London, W.C., Agents.