Improvements in Brakes.
Year: 1899

page_text: Date of Application, 18th Oct., 1899-Accepted, 16th Bec., 1899
[Communicated from abroad by LA SOCIÉTÉ ANONYME DES FREINS AUTOMATIQUES
"STOP," of 74, Boulevard Haussmann, Paris, France.]
Improvements in Brakes.
I, ERNEST DE PASS, of 78, Fleet Street, in the City of London, Fellow of
the Chartered Institute of Patent Agents, 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 the letters and figures marked thereon,'
that is to say:-
This invention relates to rope or hand brakes, and has for its object to produce
by a very slight effort a much more powerful braking action than can be obtained.
by brakes of this kind employed at the present time.
In ordinary rope or band brakes, when a pull is applied to one of the free ends,
it is by the rotation of the wheel, transmitted to the other end at a power multi-
plied in proportion as the rope or band is wound around the hub. Now the
essential feature of my invention is to transfer back to the initial or starting
end a portion of the power obtained on the other end so as to automatically
increase the initial effort and to thus produce a most powerful braking action.
In the accompanying drawings:
Fig. 1 represents diagrammatically an arrangement in which both rope-ends
are upon one and the same side of the hub.
Fig. 2 represents diagrammatically a construction wherein the two ends or
pieces of the rope are one upon each side of the hub.
Figs. 3 and 4 illustrate by way of example an arrangement for operating the
brake automatically.
Let (Fig. 1) be a shaft or drum having a rotary motion in the direction
indicated by the arrow, and b a rope wound around the same. The ends of this
rope are fastened to a spring lever c, d, adapted to turn on a shaft or fulcrum e
situated nearer to d than to c. The movements of the lever are limited by two
stops f, and g.
Supposing, under these conditions, that the respective working parts occupy
the position represented in full lines, the grip of the rope upon the shaft or
drum being nil, and supposing we exert a pull of say p, kilogrammes upon the
end h of the rope b this will at once cause the rope to grip the shaft or drum a.
It will be obvious that this pull will be transmitted to the piece of the rope
at a degree increased in proportion to the number of times the rope b is wound
around the shaft. a. Assume for instance that the strain thus transmitted to the
end of the rope, equals k, p, kilogrammes. This strain or effort causes the
lever c, d, to turn around its axis e, and would place it in the position d, e, if
the rope b were sufficiently extensible (for c, c¹ is larger than d, , because e c is
larger than e, d.). But as the rope is inextensible the lever c, d. actually bends
and assumes the position de c¹ thus exerting upon the piece h of the rope b

page_text: an additional pull which will be transmitted to the piece i immediately after
having thus been multiplied to the extent of the factor k above, so that ultimately
the tension of the piece i is much greater than it would be without the employ-
ment of the spring lever.
When the end c¹ of the lever is by any suitable means pushed in the opposite
direction to that of the pull exerted by the spring upon the rope, all the respec-
tive parts will resume their initial position represented in solid lines.
Fig. 2 represents a similar arrangement in which however the two ends of
the rope are upon opposite sides of the drum. In this case it is necessary to
connect the end c of the lever to the end of the rope by a rigid connecting
rod k, and a transmitting lever m, adapted to turn on a fixed pivot n. In this
case one or the other of the two levers, cd, or m, may be made flexible. Accord-
ing to Fig. 2 the lever m' is made flexible and the lever cd, rigid.
As will be seen, the main feature of my invention is to judiciously utilise a
considerable portion of the power obtained by the grip of the rope b on the
shaft or drum to increase the initial pull and thus to obtain a considerable
increase of the resulting effect.
It is evident that my invention may be carried out in a number of ways and
be applied to any different problems, and it should be understood that I reserve
the property of the principle, irrespective of what may be the ultimate appli-
cation. One application however is to the stopping of vehicles and I will now
describe by way of example an improved brake on the principle I have explained.
In this application I have adopted the second arrangement, and it will be
seen that in Figs. 3 and 4 like letters of reference designate the corresponding
parts of Fig. 2.
As there are two brake wheels and consequently two ropes b, I have for the
sake of simplifying the construction, arranged one single connecting rod in
the central plane of the vehicle. The ends i of the rope are fastened at d to
the corresponding shoe supports. The two shoe supports are mounted on a
single shaft e suitably connected to the frame of the vehicle.
The two ends h of the ropes are connected by a leaf spring m suspended from
the frame of the vehicle by means of small chains o. To the centre of the
shaft e the lever e c is keyed, the same being longer than the lever e d, and its
extremity being coupled by a rigid connecting rod k to the centre n of the
spring m. The connection between the rod k and the spring m is effected by
means of an adjustable milled nut p, serving for regulating. The connecting
rod is adapted to slide in a guide fixed below the axle, and carries a stop r.
The action of this arrangement will be readily understood. A
effort exerted upon the rope ends h, is sufficient to cause the ends to apply
very slight
the brake shoes against the rim of the wheel and simultaneously to effect the
rotation of the lever e c which latter by the connecting rod k and the spring m
transmits an additional initial tension to the rope ends h.
The
In order to render the brake automatic all that is necessary is to connect the
ends s of the spring m to an appropriate link which is subject to the haulage
or pull on the vehicle. This may for instance be effected by fastening the
swingle u to a rod sliding in the fore-carriage and carrying a stop z.
length of the link or band t which may for instance be a steel wire is such that
the stop of the connecting rod k, will bear against the fixed piece g a little before
the stop z bears against the fore carriage. Under these conditions the spring m
which is slightly bent draws the piece back with a force adjustable by the
milled nut p, and which force may for example be made equal to p kilogrammes.
Consequently as long as the tractional effort or draft pull is greater than p kilo-
grammes, the abutment will bear against the fore-carriage and the vehicle
will be in motion.
As soon however as the pull becomes less than p kilogrammes, the ends s of
the spring m become free and exert upon the rope ends h a tension sufficient to
cause the
rope to adhere to the hub of the wheel and consequently to throw the

page_text: shoe-brake and the ordinary rope-brake into operation. At the same time the
lever and the connecting rod k are set in motion and the centre n of the
spring m is forced back to a greater extent than the points of connection of the
rope ends h, seeing that the lever e, c, is larger than the lever e, d. Thus a
considerably greater braking effect is produced.
The initial tension of the ropes may be produced by other means than the
permanent tension of the spring m, for instance by a counter-weight which may
be one of the parts of the brake itself (the weight of the brake shoes, the levers,
the spring, &c.) if they be arranged as indicated in dotted lines in Fig. 3, or
by other springs of less strength. In like manner the transmission of the pull
from the horse to the ends of the spring may be effected in any other appro-
priate manner.
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. A rope or band brake characterised by a spring-lever cd, turning on a
fulcrum e, and connected to the free ends h and i of its rope (or band) b, these
ends being situated on the same side of the revolving shaft or drum whilst
the fulcrum e of the lever is situated between the points of attachment of the
rope and nearer to one than to the other, substantially as described with reference
to Fig. 1, and for the purpose set forth.
2. A brake of the kind referred to, having the ends and i of its rope (or
hand) 6 situated upon opposite sides of the revolving shaft or drum a; these
ends being attached respectively to levers ed and m, of which one, viz. m, is a
spring lever, and which are connected by a rigid connecting rod k, substantially
as described with reference to Fig. 2 of the drawings for the purpose set forth.
3. A brake of the kind referred to having a leaf-spring m, the centre of which
is connected by a rod to a lever e c keyed on the shaft e which unites the two
brake-shoe supports e d, the ends h and i of the brake ropes being respectively
connected to the ends of the spring m and to the said shoe supports, substan-
tially as described.
4. An automatic brake formed by connecting the ends ss of the spring m of
the brake referred to in the preceding claim, to a link or band subject to the
haulage and provided with a stop and by arranging on the connecting rod k
a stop adapted to come in contact with a fixed piece 7, substantially as described
with reference to Figs. 3 and 4.
5. A rope or band brake provided with means whereby a strain on one end
of the rope or band is transmitted in an augmented ratio to the other end and
is thus caused to re-inforce the initial strain substantially as described.
Dated this 18th day of October 1899
ERNEST DE PASS,
Chartered Patent Agent.
78, Fleet Street, London, & 5A, Market Street, Nottingham.