provements in Belts for Curved Pulleys and in Machinery for the Manufacture thereof.
Year: 1894

page_text: COMPLETE SPECIFICATION
Improvements in Belts for Curved Pulleys and in Machinery for the
Manufacture thereof.
I, NEWNHAM BROWNE, of 73 Cheapside, in the City of London, Chartered
Patent Agent, do hereby declare the nature of this invention and in what manner
the same is to be performed, which has been communicated to me by Paul
Schivner, of Dresden in the Kingdom of Saxony and Empire of Germany,
Merchaut, to be particularly described and ascertained in and by the following
statement:-
In using woven driving belts of the usual kind, rectilinear in cross section,
this disadvantage is always experienced that when applied to arched or curved
pulleys they do not touch all over, and consequently transmit less power relatively
to their width. If the full transmission of power corresponding to their widths is
to be obtained, such belts must be stretched very tight on their pulleys and must
be maintained so tightened. This however not only causes considerable wear of
the belts as well as of the bearings, but the friction produced in the latter is
increased and consequently also the power required to overcome it, thereby greater
loss of power is produced.
The object of the present invention is to obviate these difficulties in connection
with woven belts.
It consists in giving to the belt a curved sectional shape corresponding to that
of the belt-pulley as is shown in Fig. 1, of the accompanying drawing. This enables
the belt to bear on a curved pulley over its entire width, and hence effectively to
transmit power over its entire face without having to be excessively tight.
The following process serves to produce such belts.
Every chain-thread in the loom as well as the fabric produced therefrom, i.e. the
belt, is guided in the line of a curve (transversely) corresponding to that required
in the belt to be produced. This is shown as to the chain in Fig. 2, as to the
fabric in Fig. 3.
Fig. 4 and the following figures show how this is effected in the loom for the
chain as well as for the fabric. Fig. 4 is a diagram of a loom, and of its principal
parts.
k, k are the chain threads; a, a the beams; b the harness; c the race; d the breast
beam, and G the fabric made by the loom.
"
The chain may be guided by the beams a, a, in which case these are made of the
necessary degree of convexity, as illustrated in Fig. 5, or a ❝ comb
may be
provided for each set of chain threads, and placed between the beam a and the
harness b, as shown in dotted lines at f, for the lowermost chain, the upper edge
of such comb which supports and guides the corresponding chain being suitably
curved. See Fig. 6.
To guide the belt when woven in a curved shape the breast beam for drawing
the same along is made convex, as well as the shafts or beams shown in Fig. 5.
A pressure roller d', concave, to correspond with the convex shape of the breast
beam d, bears against the latter. To take off the belt taut from the rollers d, d',
and to conduct it to the cloth-beam conveniently placed in order to stretch it so as
to equalise it, several other pairs of rollers are placed behind the rollers d, d¹ in
each pair one e, convex, according to the curve of the belt, the other concave, to
agree with the former.
Each pair of these rollers moves at a somewhat higher velocity than the last
so that between every two pairs the fabric or belt is slightly stretched.

page_text: Having now particularly described and ascertained the nature of my invention
and in what mauner the same is to be performed; as communicated to me by
my foreign correspondent, I declare that what I claim is :-
(1) Woven driving belts of the curved sectional shape described for the purpose
of enabling the belt to bear on the pulley throughout its entire width.
(2) The method of and mechanism for producing curved driving belts (such as
referred to in Claim 1) which method consists in arranging the chain threads for
producing the belt in a curve either by making the beams (a) convex, or by
arranging under each set of chain-threads a "comb" f, the upper edge whereof
is curved guiding the woven belt over a breast beam convex to correspond to the
same in shape, a correspondingly concave roller pressing against the breast beam,
the belt being finally equalised by drawing off rollers, e, e¹, moving with a gradually
increasing surface velocity.
Dated the 22nd day of October 1894.