An Improved Friction Clutch.
Year: 1892

page_text: Date of Application, 24th June, 1892
Complete Specification Left, 24th Mar., 1893-Accepted, 20th May, 1893
PROVISIONAL SPECIFICATION.
An Improved Friction Clutch.
JAMES REGINALD CHURCHILL of 37 Alexandra Road, Finsbury Park, N.,
Engineer, and FREDERIC GEORGE SEELEY of "Woodville," Stanley Road, South
Woodford, Essex Engineer do hereby declare the nature of this invention to be as
follows:-
Our invention relates to the construction of a friction clutch for connecting and
disconnecting revolving bodies such as shafting, pulleys, or other devices for trans-
mitting power, in which the power is transmitted from the driving shaft to the
driven shaft by means of a number of radial spring arms connected to one shaft and
bearing on a disc; or sprung into or onto a box or drum; on the other shaft or
body to be connected. In one form the radial spring arms on the driven shaft are
sprung into a hollow box or drum on the driving shaft. The normal position of
the spring arms being at right angles to the axial line of the shaft, and their radii
in that position being greater than the radius of the drum into which they have to
enter, it is evident that the springs must be forced into a bow shape in order to
enter the drum and the continual effort to regain their normal position will cause
a wedging action between their ends and the inside periphery of the drum, causing
friction in proportion to the strength of the springs. A split ring, segments, or
blocks, may be interposed between the ends of the springs and the drum in order to
obtain more frictional surface than is possible with the springs bearing direct.
To stop the transmission of power from one shaft to the other it is only necessary
to bend the springs further froin their normal position, thus reducing their effective
This may be
radial length and removing the frictional surfaces from contact.
effected by any suitable means, such as a cam, lever, or screw carried by a collar
or collars on the driven shaft and operated by hand in any convenient manner.
The principal advantage in a clutch constructed according to this invention is
the storing up of the power required for driving in the spring ärms, needing only to
be released to come into action; thus there is no pressure, and consequently no
friction, on any moving part.
When the clutch is driving the only wear is that due to the weight of the parts
operated by hand; no pressure being required to be put on by hand as in all other
clutches.
When disconnected, pressure is put on by the hand gear, but as the parts are
then stationary no wear can take place.
Dated this 23rd day of June 1892.
FRED. U. SMEL
JAMES R. CHURCHILL.
COMPLETE SPECIFICATION.
An Improved Friction Clutch.
JAMES REGINALD CHURCHILL of 37 Alexandra Road, Finsbury Park in the
O County of Middlesex, Engineer and FREDERIC GEORGE SEELEY of Stanley
Road. Woodford in the County of Essex, Engineer, 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 :-
Our invention relates to the construction of a friction clutch; for connecting and
disconnecting revolving bodies such as shafting, pulleys, or other devices for trans-
mitting power in which the pressure to obtain the necessary friction for driving is
D11

page_text: stored up within itself.
In one form the clutch has radial spring arms on the driven
shaft, sprung into a hollow box or drum on the driving shaft. The normal position
of the spring arms being at right angles to the axial line of the shaft, and their
length, in that position, being greater than the radius of the drum into which they
have to enter, it is evident that the springs must be forced into a bow shape in
order to enter the drum, and the continual effort to regain their normal position
will cause a wedging action between their ends and the inside periphery of the
drum, and friction in proportion to the strength of the springs. A split ring,
segments, or blocks may be interposed between the ends of the springs and the
drum in order to obtain more frictional surface than is possible with the springs
bearing direct.
In another form the radial springs may bear, at their outer ends, against a disc or
equivalent having a conical circumference, thus forcing the conical disc or equiva-
lent into a correspondingly shaped piece on the driving shaft.
Referring to the drawings-
Figs. 1 & 2 Sheet 1-represent respectively a longitudinal section and sectional
end elevation of a clutch in which 1. is the driving shaft having keyed to it the
driving drum 2. 3. is the driven shaft having keyed to it the body 4. carrying the
springs 5. held by the rings 6. and 7. and the bolts S.
The springs 5 carry frictional blocks 9. held in shoes 10 by bolts 11. These
blocks are forced by the springs to bear against the ring 12. which is held in
position by the ring 13 and right and left hand screws 14 abutting against the
ring 13" which bears against the flange of the body 4.
In the position shown the clutch is disconnected. To connect, it is only
necessary to slack back the screws 14. thus allowing the springs to partially regain
their normal position, and wedging the frictional blocks against the inner periphery
of the driving drum 2.-when power will be transmitted by the blocks, by means of
the projections 12" on the ring 12, to the feather 15, and thereby to the driven
body and shaft.
Figs. 3 & 4-Sheet 2-are respectively a longitudinal view-partly in section-
and an end elevation, of a clutch in which 1 is the driving shaft, having-keyed to it
the driving drum 2. 3. is the driven shaft having keyed to it the body 4 carrying
the radial springs 5 held by the ring 6. and the bolts 7. The outer ends of these
springs bear against the disc 8 which is free to slide longitudinally on the pins 9
carried by the body 4.
In the position shown the clutch is driving, the springs being prevented from
regaining their normal or vertical position by the contact of the tapered or conical
surfaces of the driving drum 2. and the disc 8.
Thus the power is transmitted from the drum 2, through the disc 8 and pins 9 to
the driven body and shaft. In some cases it may be more convenient to substitute
for the springs, as shown, one or more coil springs as shown dotted at 5".
To disconnect, the hand lever is moved in the direction of the arrow, when the
cam 10. bearing against rollers 11. moves the sleeve 12 against the boss of the
disc 8-forcing the frictional surfaces out of contact.
Figs. 5 and 6-Sheet 3-are respectively a longitudinal view-partly in section,
and an end elevation, of a clutch in which 1 is the driving shaft having keyed to it
the driving drum 2. 3 is the driven shaft having keyed to it the body 4 provided
with jaws 4" carrying levers 5 having frictional blocks 5" forced against the inner
periphery of the driving drum by the tension of the springs 6.
The hand lever 11. is carried by bosses on the sleeve 12. and is arranged to
operate levers 10 connected by links 9 to the loose ring 8 bearing on the flange of
the sleeve 7.
In the position shown the clutch is driving. To disconnect,-the hand lever is
moved into the dotted position thus drawing forward the ring 8, and with it the
sleeve 7 which carries over the inner ends of the levers 5 thus bringing the frictional
surfaces out of contact.
It is important to notice that in a clutch, constructed according to this invention,

page_text: the thrust of the springs, whether driving or not, is entirely taken
up within the.
clutch. Thus there is no tendency whatever to put an end thrust on the shaft and
bearings. In all cases the loose rings or sleeves which carry, and are operated by,
the hand levers; are prevented from revolving by any suitable means.
In clutches as generally constructed such rings as these have to transmit the
pressure to a revolving body during the whole time that the clutch is in operation,
and are therefore subject to continuous friction. This causes serious loss of power.
In our improved clutch, the pressure is only put on when it is desired to disconnect;
consequently the friction and wear are only taking place during the operation of
disconnecting. The power absorbed is therefore practically nil.
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,
A friction clutch provided with a spring or springs which, when the clutch is.
disconnected, is or are, held in the most stressed condition by the hand gear, lever,
or levers; and which when released by the hand gear, is, or are, free to bring and
force the frictional surfaces together substantially as described and shown on-the-
accompanying drawings.
Dated this 23rd day of March 1893.
JAMES K. CHURCHILL.
FRED. G. SEELEY.