IMPROVEMENTS IN FRICTION CLUTCHES
Year: 1887

page_text: Date of Application, 7th July, 1887
Complete Left, 7th Apr., 1888
Complete Accepted, 11th May, 1888
1 OSBORNE REYNOLDS of the Owens College Manchester in the County of
Lancaster Professor of Engineering do hereby declare the nature of said Invention for
IMPROVEMENTS IN FRICTION CLUTCHES to be as follows:-
:-
In my improved friction clutch I employ one friction disc mounted on a feather key
on the shaft to which power is to be transmitted and a second friction disc loose on the
shaft. The first named friction disc is controlled by a clutch lever and to the boss of
the second disc is secured one end of a spiral spring or flexible band of metal which is
coiled round a sleeve or pulley fixed on the shaft the other end of the spring or band
being secured to the boss of a bevel wheel friction disc clutch box or like part which is
mounted loosely on the shaft and receives motion from a bevel wheel or its equivalent
on a shaft driven in any convenient manner.
The improved clutch is operated as follows:
-When the first friction disc is moved
into contact with the second disc driven by the spiral spring from the bevel wheel the
resistance caused by the frictional contact between the two dises binds the spiral spring
on the surface of the sleeve which is thus driven and so drives the shaft upon which
it is secured.
When the first disc is moved out of contact with the second disc the coil unbinds
itself from the sleeve and so releases the shaft.
My improved clutch is equally applicable to transmit power from in place of to a
shaft in this case the first friction disc is mounted and free to be moved on a feather
key in the driving shaft the second,or loose friction disc and the fast sleeve with the
spiral spring give motion when the friction discs are brought into contact to the loose
bevel wheel friction disc or clutch box which in its turn conveys motion to the bevel
wheel or equivalent on the shaft to be driven.
"

page_text: Improvements in Friction Clutches.
I OSBORNE REYNOLDS of the Owens College Manchester in the County of
Lancaster, Professor of Engineering, 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:-
In my improved friction clutch I employ one friction dise mounted on a feather
key on the shaft to which power is to be transmitted and a second friction
disc loose on the shaft. The first named friction disc is controlled by a
clutch lever and to the boss of the second disc is secured one end of a spiral
spring or flexible band of metal which is coiled round a sleeve or pulley fixed on the
shaft the other end of the spring or band being secured to the boss of a bevel wheel,
friction dise, clutch box or like part which is mounted loosely on the shaft and receives
motion from a bevel wheel or its equivalent on a shaft driven in any convenient
manner.
The improved clutch is operated as follows:-When the first friction disc is moved
into contact with the second disc driven by the spiral spring from the bevel wheel the
resistance caused by the frictional contact between the two dises binds the spiral spring
on the surface of the sleeve which is thus driven and so drives the shaft upon which it
is secured.
When the first disc is moved out of contact with the second dise the coil unbinds
itself from the sleeve and so releases the shaft.
My improved clutch is equally applicable to transmit power from in place of to a
shaft in this case the first friction disc is mounted and free to be moved on a feather
key in the driving shaft the second or loose friction disc and the fast sleeve with the
spiral spring give motion when the friction dises are brought into contact to the loose
bevel wheel, friction dise, or clutch box which in its turn conveys motion to the bevel
wheel or equivalent on the shaft to be driven.
And in order that my Invention may be fully understood and readily carried into
effect I will describe the accompanying sheet of Drawings reference being had to the
letiers marked thereon.
The Drawing is an elevation partly in section showing two of my improved friction
clutches applied to one of the valve rods of a steam engine for the purpose of turning
it axially in one direction or the other according to the rise or fall of the governor
balls and so accelerating or retarding the cut off of the valve as required.
In this arrangement.-a designates the valve rod which it is required to turn axially
either backward or forward according to the rise or fall of the governor to which the
said rod a is connected and free to be moved vertically in its bearings. On the valve
rod a are mounted two of my improved friction clutches each consisting of the following
parts A friction disc d mounted and free to slide on a feather key on the rod a: a
friction dise or equivalent e mounted loosely on the rod a and connected by a coiled

page_text: spring to a bevel gear g mounted loosely on a bush on the rod a, the coiled
spring passing over a sleeve or pulley which is fixed on the rod a. Each friction
disc d is held normally clear of its dise or equivalent e by means of a clutch leverj
which is secured in the required position by a screw on a rod . Both the bevel
gears 9 are driven constantly but in opposite directions by a bevel wheel / fixed on a
shaft m driven by a bevel wheel from a bevel wheel on the governor sleeve and the
bevel gears being connected by the springs f to the friction discs or equivalentse the
latter are also constantly revolving in opposite directions.
When the rod a is either raised or lowered by the governor one of the revolving
friction discs or equivalents e is brought against its corresponding friction disc d and
as the revolving motion of the disc e is checked by frictional contact with the disc d
the spring to which the said disc e is attached is caused to bind upon the sleeve or
pulley and thereby to drive the rod a in the direction required to accelerate or retard
the cut off until the engine has regained its normal speed and the governor balls resume
their normal position and move the road a vertically up or down as the case may be and
withdraw the disc e from its disc d.
It will readily be understood that the particular case above described and illustrated
by the Drawing is only one out of the many applications and arrangements of my
improved friction clutch which may be made and some of which I will now point out.
My improved friction clutch may be employed for the purpose of connecting
and disconnecting at will two revoluble parts of a machine which for convenience of
description I will hereinafter designate the driver and the follower these parts being
so mounted that they can only revolve co-axially. In this case I should employ
a helical spring or flexible metal band coiled loosely when not in action round a sleeve
or equivalent. One end of the coil would be secured either to the driver or the follower
and the sleeve or equivalent would be fixed upon the other part. The coil is so wound
that if attached to the driver the motion of its attached end will when the other
or loose end be retarded cause the coil to wrap tighter and bind on the sleeve
or equivalent until the friction is sufficient to carry the same and the part upon which
it is fixed round with the coil. If attached to the follower the sleeve or equivalent
being on the driver the coil would be wound in such a way that any motion of
the loose end in the direction of the driver will bind the coil on to the sleeve until the
friction is sufficient to drag the coil and follower with the sleeve.
What I have called the unattached or loose end of the coil I attach to some suitable
form of friction clutch the other portion of which can be moved in and out of gear by
a clutch lever such that when the coil is attached to the driver friction can be brought
to bear to prevent the loose end from revolving with the fixed end in the manner
already described with reference to the Drawing until by binding the coil upon
the sleeve the frictional contact carries round the sleeve and the follower with the coil.
Also by taking off the friction on the loose end the grip of the coil may be relaxed and
the coil liberated to turn without the sleeve and the follower. When the coil is attached
to the follower the sleeve or equivalent being on the driver the friction clutch is such
that friction can be brought to bear on the loose end of the coil to cause this end
to revolve with the sleeve until the coil grips the sleeve so that the frictional contact
carries round the coil and attached follower with the sleeve.
The helical spring or flexible band is preferably made of steel and is of sufficient
strength at the attached end to stand the strain put upon it and in certain cases this
strength is maintained throughout the entire coil but I prefer to employ for the coil a
wire or strip or band the strength and size of which gradually taper or diminish from
the attached end to the loose end by which means the amount of friction necessary to
bring the coil into action may be rendered as small as convenient without reducing the
power or efficiency of the clutch.
The number of turns in the coil is regulated by or adjusted according to the holding
power required.
The chief advantages obtained by the use of my improved clutch are that the driving
and driven parts can be connected or disconnected with perfect ease and smoothness
even when running at full speed by the application of forces which may be made as

page_text: small as convenient without reference to the power of the clutch since when in gear the
tendency is always for the coiled spring to bind itself more tightly on the fast sleeve or
equivalent and thus to overcome the resistance of the part to be driven and when the
loose end is released the coil frees itself from the sleeve without any other force.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what I
claim is
1. The improved friction clutch consisting of a helical spring or flexible metal hand
coiled loosely round a sleeve or equivalent fixed upon the follower or part to be driven
one end of said spring or band being attached to the revolving part or driver in such
manner that if the other end be held or retarded the coil will bind tightly on the sleeve
and carry it round with the follower or vice versi as herein described.
2. The combination of a friction clutch one portion of which is arranged to be put
in and out of gear with the other portion by a clutch lever, a coiled spring or flexible
metal band attached at one end to one portion of said friction clutch and at the other
end to a revolving part or driver, and a sleeve or equivalent fixed upon the follower or
part to be driven all arranged and operating substantially as and for the purposes
herein set forth.
3. The construction combination and arrangement of parts embodying my
improvements in friction clutches substantially as herein described and as illustrated
by the accompanying Drawing.
H. B. BARLOW,
17, St. Ann's Square, Manchester,
Agent for Applicant.