An Improved Friction Clutch,
Year: 1894

page_text: Date of Application, 15th May, 1894
Complete Specification Left, 15th Feb., 1895-Accepted, 16th Mar., 1895
.
An Improved Friction Clutch,
We, WILLIAM HENRY CRANSTONE, of 25 High Street, Hemel Hempstead, in
the County of Hertford, Engineer, and WILLIAM ROBERT HAY, of 13 Christchurch
Road, Hemel Hempstead aforesaid, Engineer do hereby declare the nature of our
said invention to be as follows:-
.
The object of our invention is to construct an improved form and arrangement
of friction clutch for pulleys, coupling shafts, and analogous applications.
In applying our invention to an ordinary coupling for shafts pulleys and the like,
we use a drum or cylinder, one end of the cylinder being uncovered. Within this
cylinder we insert, loosely, an expanding split ring and a disc. The disc is bored,
in diametrically opposite positions, to receive the circular ends of two elliptical
plugs or cams. The elliptical portions of these plugs or cams enter and engage in
or with portions of or attachments to the split ring. One cam is placed at or near
the meeting of the split ends, and the other diametrically opposite. The function
of one cam is, by a partial rotation upon its axis, to expand the ring, and the
function of the other cam is, by a similar and simultaneous movement to force the
ring outward into frictional contact with the shell, and on a reversal of the move-
ment this cam is made to draw the ring inward and sustain the weight of same
when its weight would act disadvantageously. The plugs are operated by two
segmental levers one end of each lever being attached to one of the plugs, and the
other end attached to a forked lever. The forks of these levers are attached, by
slots and pins to a sliding sleeve which is carried round with the shaft and operated
by a lever or other contrivance working in a groove in the boss of the sleeve.
When the sleeve is drawn along the shaft, away from the drum, by a forked
lever or otherwise, the inner ends of the segmental levers are drawn inwards by
the forked levers; the plugs are thereby partially rotated so as to allow the ring
to contract, thus leaving the shaft and drum free to revolve independently. The
contrary movement causes the ring and drum to engage and the coupling is
effected.
It is obvious that the driving mechanism may be attached to the shaft or the
drum as found most convenient.
Dated 15th Man 1904
We, WILLIAM HENRY CRANSTONE, of 25 High Street, Hemel Hempstead, in
the County of Hertford, Engineer, and WILLIAM ROBERT HAY, of 13 Christchurch
Road, Hemel Hempstead aforesaid, Engineer, do hereby declare the nature of our
said invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
The object of our invention is to construct an improved form and arrangement
of friction clutch for pulleys, coupling shafts, and analogous applications.

page_text: In applying our invention to an ordinary coupling for shafts, pulleys, and the
like, we use a drum or cylinder, one end of the cylinder being uncovered. Within
this cylinder we insert, loosely, an expanding split ring and a disc. The disc is
bored, in diametrically opposite positions, to receive the circular ends of two
elliptical plugs or cams. The elliptical portions of these plugs or cams enter and
engage in or with portions of or attachments to the split ring. One cam is placed
at or near the meeting of the split ends, and the other diametrically opposite. The
function of one cam is, by a partial rotation upon its axis, to expand the ring, and
the function of the other cam is, by a similar and simultaneous movement, to force
the ring outward into frictional contact with the shell, and, on a reversal of the
movement, this cam is made to draw the ring inward, and sustain the weight of the
same, when its weight would otherwise act disadvantageously. The plugs are
operated by two segmental levers, one end of each lever being attached to oue of
the plugs, and the other end attached to a forked lever. The forks of these levers
are attached to a sliding sleeve which is carried' round with the shaft and operated
by a lever or other contrivance, working in a groove in the boss of the sleeve.
And in order that our said invention may be particularly described and ascer-
tained, reference is hereby made to the accompanying drawings, in which similar
figures of reference indicate corresponding parts.
Fig. I is an elevation of our invention, as applied to an ordinary driving pulley,
the clutch being disconnected.
Fig. 2 is a sectional elevation of the same.
Fig. 3 is a view of the clutch on the line 5-5 of Figs. 1 and 2.
Fig. 4 is a section on the line 6-6 of Figs. 1 and 2.
The boss of the belt pulley 7 is keyed to the boss of the cylinder 8, so that both
may revolve together. The boss, of the cylinder 8 is loose on the shaft 9. 10 is a
sliding sleeve. 12 is the split ring, capable of being expanded so as to fit the
inside of the cylinder 8, and engage the same. 13 is a disc, the boss of which is
keyed to the shaft 9. 14, 14, are two forked levers pivoted to the boss of the
sleeve 10, and carrying at their outer ends adjustable knuckles 15, working
in sockets 16 at the outer ends of the two segmental levers 17. These
levers have slots 11, 11 formed in the ends, to allow of their rolling end on upon
one another, thereby ensuring an equal pressure on the levers 17 and plugs or
cams 19 and 20, should the adjustment of the forked levers 14 be made unequal.
The ends of these levers at 18 carry spindles which pass through the disc 13 and.
carry at their inner ends elliptical plugs 19 and 20.
When the sleeve 10, with its connections, is drawn away from the 'pulley 7, as
shown in Figs. 1 and 2, the split ring 12 is contracted to its minimum diameter and
the shalt 9 runs free of the pulley 7:
When the pulley 10 is moved closer to the pulley 7, the levers 14 press outwards
the segmental levers 17, as shown in Fig. 3. This movement causes the partial
rotation of the bosses 18 and the elliptical plugs 19 and 20. The plug 19 presses
the split ring '12 firmly against the inner surface of the cylinder 8, and, at the same
time, the plug 20 expands the split ends of the ring 12. By this combined move-
ment the ring 12 is held in close frictional contact with the inside of the cylinder 8,
as shown in Fig. 4, and the, pulley 7 is accordingly carried round with the shaft.
It is obvious that the driving mechanism may be attached to the shaft or the
drum, as found most convenient.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The improved friction clutch, substantially as and for the purposes described.
2. In a friction clutch, the combination of a sleeve 10 turning with the shaft 9.;
links or levers 14 pivoted to the sleeve in the manner described, and to the outer
ends of segmental levers 17; cams or plugs 19, 20, capable of expanding the split
ring 12 and engaging and clutching an ordinary cylinder 8 keyed to a belt pulley 7

page_text: or an equivalent device for communicating rotary motion, severally operating
substantially as hereinbefore described and illustrated by the drawings.
11th Wah 1805
GEO.
DOWNING,
8, Quality Court, London, W.C., Agent.