Improvements in Expanding Pulleys.
Year: 1898

page_text: Date of Application, 7th Oct., 1898-Accepted, 12th Nov., 1898
COMPLETE SPECIFICATION.
Improvements in Expanding Pulleys.
A communication to me from PIERRE MALVEZIN, of Bordeaux-Caudéran, in
the Republic of France, Engineer.
I, EDMUND EDWARDS, of the Firm of Edwards and Co., Chartered Patent Agents
and Engineers, of 65 and 66, Chancery Lane, in the County of Middlesex, 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, and accompanying drawing, that is to say:-
The present invention has for its object improvements in pulleys, the diameter
of which can be varied during their rotation.
The improved pulley is illustrated in the accompanying drawing, in which
Figure 1 is a front view of the pulley, partially in section, and Figure 2 a
cross section of the same,
Upon the shaft is keyed a wheel a¹ by means of the nave a. The spokes
of the outer rim of this wheel are provided with radial slits f which serve as
guides for the heads or pins e of the spindles c, which pins slide in the guides.
The spindles c are screwed and can screw in and out of sockets b, which are
screwed inside, and have at their lower ends bevelled toothed wheels b¹ engaging
with the corresponding toothed wheels h and h', which turn freely upon the nave a.
V is a friction-brake which when applied to the rim y of one of the wheels h
or , stops the wheel to which it is applied. This will produce a rotation of
the toothed wheels b¹ and the sockets b, causing thereby a radial movement
in or out of all the spindles c. This movement causes an enlargement or a
diminution of the diameter of the pulley. Instead of screwed spindles and
sockets, other equivalent devices may be used.
The rim g of the pulley forms a spiral spring bearing on the supports e
in such a manner that one of its ends can enter the slits, this being ensured
by means of guides d fixed to the heads of the spindles c. The other end of
the spiral ring is fixed to one of the spindle heads e¹ at a, a, (Figure 1).
The guides d are curved and arranged in such a manner that when the diameter
of the pulley is diminished, the free end of the spiral rim enters the slits, its
outer surface forming a circle which receives the belt.
A further advantage of the improved pulley is that its weight is considerably
less than that of an ordinary pulley.
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. A pulley, the diameter of which can be varied whilst rotating, consisting
of a spiral spring forming the rim of the pulley and connected with bevilled
toothed wheels fitted freely on the nave of the pulley, one or other of the toothed
wheels being held by a brake when required, in such manner that the other
017

page_text: toothed wheel, by means of screwed spindles moving in corresponding sockets,
or by equivalent devices, causes the spiral spring to be contracted, or expanded,
substantially as described and illustrated.
2. In pulleys of the kind described in Claim 1, the guides provided for the
spiral spring, so that its end may certainly enter slits fitted in the spindle
heads, these guides being fixed to the spindle heads, substantially as described
and illustrated.
D1
1000
www
1030
EDWARDS & Co.,
Chartered Patent Agents, 65 and 66, Chancery Lane, London,
Agents for the Applicant.