Improvements in Pulleys.
Year: 1895

page_text: Date of Application, 23rd Aug., 1895
Complete Specification Left, 16th Apr., 1896-Accepted, 6th June. 1896
PROVISIONAL SPECIFICATION.
Improvements in Pulleys.
I, JAMES YATE JOHNSON, of 47 Lincoln's Inn Fields in the County of
London, Gentleman, do hereby declare the nature of this invention (which has
been communicated to me from abroad by Jean Pierre Serve of 17 Quai de Cuire,
Lyons, in the French Republic, Engineer,) to be as follows:—.
This invention relates to improvements in pulleys for use with cables and for
other purposes, and has for its object to provide effective means for preventing the
cable or the like from sliding or slipping in consequence of the strain to which it is
subjected, whereby loss of power and wear or deterioration of the cable, resulting
from such sliding or slipping is avoided as well as undue stretching, caused by the
excessive tensile strains to which it has been necessary it submit it hitherto.
The invention consists in providing the pulley with a groove of a wavy or
undulating form. These undulations may be as far apart or as close together as
may be desired, and may vary in size or extent, according to the nature of the
motive power to be transmitted. The cable, or the like, is compelled by these
undulations, to bend alternately to either side, thereby exerting transverse strains
upon the projecting portions of the undulating grooves, which ensure its adhesion
to the grooved surface and effectually prevent slipping.
In order that the cable extending to the pulley in a straight line may not slip
out of the groove but may be compelled to bend laterally as it moves along, and
thus exactly enter the undulations formed in the groove, care should be taken to
make such groove sufficiently deep and also to enlarge its edges circularly, so as to
form a species of external supplemental groove of circular shape, wherein the
cable may first engage and whereby it may be guided so as eventually to
enter the undulations of the groove proper, the outline of which it is required
to follow.
The pulley may have one or more than one groove, the number depending upon
the strain or amount of power which the pulley is intended to transmit.
In the manufacture of these pulleys, whether with one or with several undulating
grooves, I may employ rotary cutters acting upon a cast metal pulley, for example,
to which is preferably imparted a slight transverse movement, produced by means
of a template.
Or the pulleys may consist of a number of pieces similar in shape and provided
laterally with symmetrical projections and recesses, so that, when such pieces are
placed in juxtaposition in such a manner that the projections of the one exactly
correspond to the recesses of the other, an undulating grooved pulley will be
obtained similar to that herein before described.
The pulley may be produced by any other suitable means, for example by
fitting within the circular groove, on either side, linings of suitable form or
outline, which may be fixed in position by means of screws or in any other "
convenient manner.
Dated this 23rd day of August 1895.

page_text: Improvements in Pulleys.
I, JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of
London Gentleman, do hereby declare the nature of this invention (which has
been communicated to me from abroad by Jean Pièrre Serve of 17 Quai de Cuire,
Lyons (Rhône) in the French Republic, Engineer) and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement :-
This invention relates to improvements in pulleys for use with cables and the
like and has for its object to provide effective means for preventing the cable or
the like from slipping or sliding in consequence of the strain to which it is
subjected, whereby loss of power and wear or deterioration of the cable or the like
resulting from such sliding or slipping are prevented, as well as undue stretching,
caused by the excessive tensile strains to which it has been hitherto necessary to
submit the cable or the like.
The invention consists in providing the pulley with a groove or grooves of a
wavy or undulating form.
These waves or undulations may be as far apart or as close together as may be
desired, and may vary in size or extent, according to the nature of the motive
power to be transmitted. The cable or the like is compelled by these waves or
undulations, to bend alternately to either side, thereby exerting transverse strains
upon the projecting portions of the undulating groove or grooves, which ensure its
adhesion to the grooved surface and effectually prevent slip..
In the accompanying drawings:-
Figure 1 shews in side elevation a pulley with a single undulating groove formed
according to this invention, Figure 2 is a section of the same drawn to a larger
scale shewing the form of the groove, Figure 3 shews in side elevation a pulley
formed with several such undulating grooves and Figure 4 is a transverse section
of a part thereof taken through the grooves.
Referring to Figure 1 the periphery or rim A of the pulley is provided with a
deep groove a the walls of which are slightly inclined so as to firmly grip the
cable, and alternately present, on either side of the central plane X of the pulley,
projecting portions similar in shape, and alternating with corresponding. recesses.
These projections may be as numerous or as few as may be required and they may
vary in size or extent at will. The result is that a series of undulations is formed
which the cable or the like is obliged to follow as it is wound round. the pulley, the
effect produced being, that the said cable or the like is retained within the
groove a and prevented from sliding or slipping under the strain to which it is
Bubmitted.
In order that the cable or the like extending to the pulley in a straight line,may
not slip out of the groove but may be compelled to bend laterally as it moves
along, and thus exactly enter the undulations formed in the groove.a, care should.
be taken to make such groove sufficiently deep and also to enlarge its edges
circularly, so as to form a species of external supplemental groove of circular
shape, wherein the cable or the like may first engage and whereby it may, be
guided so as to enter the undulations of the groove proper which it is required to
follow, and of which the equidistant inclined surfaces are made to join the circular
extensions thereof.
This arrangement is shewn in Figure 2, in which'd d are the two regular or
circular parts of the groove and x x and y y are the inclined or oblique faces of the
undulated part thereof between which the cable or the like finally enters. The
parallel dotted lines in this figure indicate the extreme positions of these inclined

page_text: faces which meet with the circular parts d d of the groove at different heights
according to their relative positions with the central plane X.
In
The pulley may have one such groove or several of such grooves, depending
upon the strain or amount of power which the pulley is intended to transmit.
Figures 3 and 4 I have shewn five such grooves a, receiving a cable or the like b.
In the manufacture of these pulleys,-whether with one or with several
undulating grooves,-1 may employ rotary cutters acting upon a cast metal pulley
for example to which is preferably imparted a slight transverse
produced by means of a template.
movement,
Or the pulley may consist of a number of discs similar in shape provided
laterally with symmetrical projections and recesses, so that, when such discs are
placed in juxtaposition in such a manner that the projections of the one exactly
correspond to the recesses of the other and they are connected together an
undulating grooved pulley will be obtained similar to that hereinbefore described.
The pulley may be produced by any other suitable means, for example, by
fitting within the circular groove, on either side, linings of suitable form or outline,
which may be fixed in position by means of screws or in any other convenient
manner.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. A pulley formed with a groove or with grooves circular at the outward part
and provided at the inward part, which is slightly conical, with corresponding
projecting and recessed parts constituting transverse waves or undulations so
that the said groove or grooves are of uniform breadth substantially as herein-
before described.
2. A pulley with an undulated groove or grooves circular at the outward part
with projections at the inward part fixed or formed on each side, so that the
projections of the one side correspond with the recesses between the projections of
the other side substantially as hereinbefore described.
Dated this 16th day of April 1896.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.