Improvements in or relating to Lifting Apparatus.
Year: 1895

page_text: Date of Application, 14th Mar., 1895-Accepted, 20th Apr., 1895
COMPLETE SPECIFICATION.
Improvements in or relating to Lifting Apparatus.
I, ANTON BOLZANI, of 118 Invalidenstrasse, Berlin N. in the Empire of
Germany, Manufacturer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to a combined coupling and brake hereinafter termed a
coupling-brake, for use in lifting apparatus, and is applicable with advantage to
any kind of lifting or hoisting gear, without necessitating any special construction
to permit its use. Moreover this coupling brake may be combined with a second of
the same kind, and this combination displays excellent qualities such as have not
been manifested hitherto by any known brake.
Apparatus constructed according to this invention comprises cylindrically-curved
wedges placed in the hollow centre of a brake-ring that can only be turned in one
direction, and pressed against eccentrically formed cam-rings mounted on the shaft
to be acted upon.
In the accompanying drawings:-
-
Fig. 1 is a partial vertical central section of one construction of apparatus
according to this invention at one end of the shaft carrying the coupling brake;
Fig. 2 is a front elevation of a part of the apparatus shown in Fig. 1 ;
Fig. 3 is a front elevation of the nave of a part of the driving-mechanism of
the apparatus shown in Fig. 1 ;
Fig. 4 represents a vertical central section at the end of a shaft carrying an
alternative construction of apparatus according to this invention, that is to say, the
coupling-brake in combination with a second similar brake;
Fig. 5 is a front elevation of a detail of the apparatus shown in Fig. 4; and
Figs. 6 and 7 are side and front elevations respectively of the cam-rings mounted
on the shaft of the apparatus shown in Fig. 4.
Like reference letters indicate like parts throughout the drawings.
hindicates the frame of the lifting or hoisting gear, whether a winch, pulley-
block, or jack or other lifting apparatus; b is a shaft carrying the gearing thereof,
to which is secured with a slight amount of slack the operative part of the driving
mechanism (crank, hand-chain wheel, belt-driven pulley, or toothed wheel), and
which is to be prevented by the coupling-brake from running back under the weight
of the load.
On this shaft is secured also, in the construction illustrated by Figs. 1 to 3, a
cam ring e consisting of two or more cylindrical sectors; while d are cylindrically-
curved cam-pieces, which are in contact, by means of their inner surfaces with the
outer-surfaces of the cam-ring e, and by means of their outer surfaces, with the
inner cylindrical surface of the brake-ring fitted with ratchet teeth fl. A pawl g
permits the brake-ring only to rotate in the lifting direction. The cam-pieces or
curved wedges d are coupled, by the pins or drivers c, with the driving-apparatus (a
crank, hand-chain wheel or other appliance) the said drivers being either, as shown
in Fig. 1, secured to the cam-pieces d and engaged in radially cut slots in the
nave a (Fig. 3) of the driving wheel or the like, or, as shown in Figs. 4 and 5,
secured in the nave a of the driving wheel, and engaged in radial slots d'in the
cam-pieces d.
The working of this brake-device is as follows:-If the hand-chain-wheel or
crank-arm, or the like, be caused to rotate in the direction shown by the arrow, in

page_text: Fig. 2, the cam-pieces d in the space between the cam-ring e and the brake-ring f
are forced in the same direction whereby the coupling of the brake-ring and
driving agent with the shaft bis effected through the cam-pieces d and cam-ring e.
The brake-ring f must therefore rotate together with the said shaft; and, in the
event of the cessation of the lifting or hoisting movement, the recoil or sinking of
the load is prevented by the pawl catching in one of the teeth of the brake-ring.
The dropping of the load is only possible if the crank other operative part be
caused to rotate in the direction opposite to that shown by the arrow in Fig. 2,
whereby the cam-pieces d are loosened in the brake-ring f. So soon as that lowering
motion ceases, the weight or load immediately, by means of the cam-ring e, brings
about a pressure of the cam-pieces d upon the cam-ring e and brake-ring and the
mechanism effectually brought to a standstill.
The alternative construction illustrated in Figs. 4 to 7 consists in the combination
of the above-described coupling brake with a screw-brake.
For this purpose the shaft has a fixed collar thereon, and a screwed-part b², and
the brake-ring f is provided with a flange f,-which lies against the fixed collar of
the shaft; while the inner cylindrical surface of the cam-ring e is fitted with a
female screw corresponding to the screw thread 2 on the shaft on which it can
move. The cam-ring e is also fitted with a flange e' which comes in contact with
the flange of the brake-ring f which it presses up against the fixed collar b'.
A leather washer i serves to give elasticity to the change between brake action
and relaxation.
If now by means of the hand-chain-wheel, crank-arm or other driving device the
cam pieces are moved in the direction of the arrow, i.e. of the lifting movement,
then the cam-ring e will also be turned and thereby up to a certain point the brake
action will hold the brake-ring fast and after the attainment of a certain degree
of resistance there will be established by means of the cam-pieces da coupling
between the cam-ring and the brake-ring so that the latter is closely connected to
the shaft and the load is thereby effectually prevented from sinking or dropping
automatically.
By the opposite motion of the cam pieces through the operation of the driving
part of the machine in the direction contrary to that shown by the arrow the
coupling of those cam pieces with the inner cylindrical surface of the brake-ring is
relaxed and the load sinks despite the brake action of the screw-brake which is
not so powerfully set in action as to entirely arrest. all motion of the load.
As soon however as the lowering movement of the driving agent is arrested the
cam-pieces d once more resume a position of rest relatively to the brake ring f by
means of the cam-ring, and call into action the full brake-power of the
apparatus.
By means of these successive variations of action and release of the two brakes,
thus united, the brake-pressure is so regularly, evenly and favourably distributed
that, with the most complete safety, an equally easy descent of the load is
provided.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is ;-
-
1. In lifting apparatus a coupling-brake between the driving crank arm or other
driving agent and the driven shaft comprising wedges such as d in operative
connection with the driving agent a cam-ring such as e on the driven shaft a ring
such as fand a detent g arranged and operating substantially as and for the purposes
herein before described.
2. The combination with a coupling-brake of the kind claimed in the first
claiming clause of a second friction-brake operating by screw-action the combined
brakes being in such operative connection that they only come into action one
after the other and one through the other both as regards their movement into and
out of gear, substantially as and for the purpose described.

page_text: 3. In apparatus of the kind claimed in the second claiming clause a cam-ring
mounted with a screw-thread upon the lifting or driven shaft a collar such as b¹ on
that shaft a brake-ring such as having a flange and a detent g substantially as
and for the purpose described.
4. The coupling-brake substantially as and for the purpose hereinbefore described
and illustrated with reference to Figures 1, 2 and 3 or Figures 45 6 and 7 of the
accompanying drawings.
Dated th: 141 1
1005
BOULT & WADE,
Agents for the Applicant.