Improvements in and relating to Clutches, Brakes, and the like.
Year: 1890

page_text: Date of Application, 19th Dec., 1890
Complete Specification Left, 19th Oct., 1891-Accepted, 21st Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in and relating to Clutches, Brakes, and the like.
We, EDWARD SHAW, of Canons Marsh, Bristol, Engineer, and. GEORGE JOHN
HARCOURT, of 5 Albert Villas, Clifton, Bristol, Gentleman, do hereby declare the
nature of this invention.to be as follows:-
This invention which relates to means for controlling the gripping power of
metallic and other coils, consists in further developments in and improvements on
devices such as are described in the Specifications of our former applications for
Letters Patent Nos. 15871 of 1887; 20613 of 1889 and 17133 of 1890.
This our present invention is applicable to coils either wholly or in part composed
of metal, either in the form of a solid strip or band, or in.the form of linked chain,
or wire rope, or rope of hemp, manilla or other suitable substance.
One feature of this our present invention consists in the provision of special
means for tightening or loosening the grip of such coils on a shaft or other rotating
body.
In our inventions forming the subjects of our said former applications for Letters
Patent a bell-crank lever is employed and so arranged that an end movement of a
collar along the shaft causes the said lever to turn on its axis and tangentially to
open or close the tail of the coil. Now, in this our present invention, a straight
lever is, under one arrangement, employed.
This lever is connected at one end to the tail of the coil, and the axis of the lever
is so fixed that the end of the tail of the coil attached to the lever moves radially to
and from the shaft. The other end of the lever also moves radially and is acted
upon by a wedge or conical surface moved along the shaft.
The coil is accordingly tightened and relaxed by such movements of the lever.
Under another arrangement a rocking shaft, having its axis parallel to that of
the main shaft, is substituted for the lever aforesaid. This rocking shaft is
provided with a couple of cranks to one of which is secured the tail of the coil.
To the other crank is attached a wedge or cone movement of which in the required
direction causes the shaft to rock and the coil to open or close.
In another arrangement a pulley is substituted for the rocking shaft aforesaid,
and over the pulley runs a flexible extension of the tail of the coil. The extended
tail is attached to a collar which slides on the main shaft. To tighten the coil the
collar is forced along the shaft, either by a spring or other suitable device, and to
relax the grip of the coil the collar is moved in the reverse direction.
Under a fourth arrangement the coil is fixed both at the head and tail, and
an expanding bush is employed which by its expanding action causes the coil to
grip.
This result is preferably obtained by wrapping the coil, wholly or in part, round
a conical surface, so that an end movement of the coil on this surface produces a
tightening or loosening action in the grip.
According to a fifth arrangement, that part of the gripped surface which is
adjacent to the tail of the coil is expanded and the necessary gripping effect
thereby obtained from the coil.
A further feature of this our present invention consists in gear or means for
putting the coil into and out of action. Such mechanisin is applicable to various
kinds of clutches. According to this part of our invention a bush lies freely on
the shaft and is prevented by collars from moving endways. At one end of the
bush is a bracket having a lug thereon which overhangs the bush. Through the
lug is bored a hole radial to the axis of the shaft. A cranked rod is placed
through this hole with the crank inwards towards the bush. On the outside of the

page_text: bush, which is turned, is a sliding collar the movement endways of which along
the shaft is regulated by the cranked rod, the cranked end of which engages in a
groove in the collar.
The latter thus actuated by revolution of the cranked rod operates either through
a toggle joint or an inclined or conical surface, on the mechanism whereby the
coil is opened or closed.
In analogous appliances the collar operates on the mechanism which controls_the
gripping devices.
Dated this 18th day of December 1890.
NICHOLAS WATTS,
Bristol Bank Buildings, Bristol, Agent.
COMPLETE SPECIFICATION.
Improvements in and relating to Clutches, Brakes, and the like.
We, EDWARD SHAW, formerly of Canons Marsh, Bristol, and now of Ashton
Gate, Bristol, Engineer, and GEORGE JOHN HARCOURT, of 5 Albert Villas, Clifton
Bristol, Gentleman, 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 :-
This invention which relates to means for controlling the gripping power of
metallic and other coils, consists in further developments in and improvements on
devices such as are described in the Specifications of our former applications for
Letters Patent, Nos. 15871 of 1887; and 20613 of 1889.
- This our present invention is applicable to coils, either wholly or in part com-
posed of metal, either in the form of a solid strip or band, or in the form of linked
chain, or wire rope, or rope of hemp, manilla or other suitable substance.
One feature of this. our present invention consists in the provision of special
means for tightening or loosening the grip of such coils on a shaft or other rotating
body.
A further feature of this our present invention consists in gear or means for
putting the coil into and out of action. Such mechanism is applicable to various
kind of clutches.
Referring to the accompanying sheets of illustrative drawings
Fig. 1 represents an arrangement, for tightening or loosening the grip of the
coil, under which a straight lever a is employed.
Fig. 2 is a section on the line, Fig. 1
The lever a is connected at one end to the tail of the coil b and the lever is so
fixed on a fulcrum e provided on the casting c that when the lever is operated the
coil moves radially to and from the shaft d at the point of attachment of the lever.
The coil is, in consequence, caused to move tangentially at its point of first contact
with the boss e of the pulley. The other end of the lever a moves radially and
is acted upon by a toggle joint link g, Figs. 1 and 3.
When it is desired to tighten the coil b, the starting rod is turned so as to
cause the two crank levers to slide the collar j along the shaft d away from the
pulley f. This allows a spring k to act and tighten the coil. To relax the grip of
the coil the action is reversed.
At Figs. 4 and 5 is illustrated an alternative arrangement for controlling the
grip of the coil b. In this arrangement a rocking shaft a¹ is substituted for the
lever a above referred to, and to it are fixed two cranks g' and g². The crank g³ is
connected to the tail of the coil b by an intermediate link and ring m. The crank g¹
bears against a cone j', movement of which in the required direction causes the
shaft a to rock and the coil b to open. Closing of the coil is effected by the action
of the spring which exerts a torsional strain upon the rocking shaft a¹ since the
spring bears at one end against the casting c¹ and at the other end against the

page_text: crank g. The ring m aforesaid carries bars n against which the outside of the coil
lies when the coil is opened. The sliding cone j¹ is moved axially on the shaft d
by means of the lever i.
At Fig. 6 is represented an arrangement in which the tail of the coil bis
carried over a pulley a² direct to the sliding collar. The pulley a² is carried by
the casting e. The collar 2 is prevented from turning on the shaft d by a
feather o and is operated axially in one direction by means of a spring / which
tightens the coil, and in the opposite direction-to relax the coil-by a hand lever
or the equivalent thereof.
In another arrangement, represented at Figs. 7 and 8, the coil b.is fixed both at
the head and tail to the casting c. On the shaft d is keyed an expanding bush el.
The casting e, which in the arrangements above described is fixed, is, in the
modification shown at Figs. 7 and 8, free to turn on the shaft d. The coil b
attached, as aforesaid, to the casting c¹ is so adjusted as to be barely loose on the
expanding bush e which at one end has a series of slots p. Centred on the
shaft d is a collar 3 free to move axially on the shaft and so arranged as to bear on
its outside against the internal face of the slotted end of the bush e. The coil is
tightened by moving the collar 3 inwards and thereby expanding the bush e'.
Reverse movement of the collar relaxes the grip of the coil.
Figs. and 10 show an arrangement under which the coil is tightened and
caused to grip the boss e in the following manner. The boss e2 is made so that
either a part or the whole of its outside surface is conical. The coil b, which is
attached at both ends to the casting, is so adjusted as to be barely loose on the
boss e². The casting c² is not only free to rotate on the shaft d, but can be moved
axially along it by a hand lever or the like. As the coil is thus moved in one
direction it engages with a larger diameter of the boss e² and is thereby caused to
grip. Reversal of the motion effects its release.
A further modification for controlling the grip of the coil is represented at
Figs. 11, 12 and 13. In this arrangement a lever a' carried on a fulcrum c¹ is con-
nected to the tail of the coil by means of a link and tail ring m. The lever a
is actuated by means of a spring and sliding collar, the spring moving the
lever so as to tighten the coil, and the sliding collar being operated to open the.
coil.
In connection with this modification for controlling the grip of the coil is
illustrated the special gear or means for putting the coil into and out of action
which constitutes a further feature of this invention.
r
Upon the shaft d is a bush q and adjacent to this a collar r. A bracket s is fixed
to one end of the bush q and is so shaped as to overhang the collar and prevent
end movement of the bush g along the shaft. At the other end of the bush q is a
bracket u carrying a crank rod t the axis of which is approximately radial to the
shaft d. The crank rod t is made with a crank pin which engages in a circular
recess in the sliding collar. Rotation of the crank rod t causes by means of the
pin tend movement of the collar along the shaft, thus actuating the coil. In this
arrangement the casting c¹ is preferably made in halves bolted together round the
shaft d. Each half carries a head block having channels w so constructed that
the coil b, which may be wound round the boss e so as to form a right or left
handed arrangement, can at its head end be passed through one of the channels
and be securely fixed by a wedge to the casting c¹.
A double coil is preferably used, one being attached to each half of the casting.
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 method of tightening and loosening the grip of a coil (composed of
metal, either in the form of a solid strip, or band or in the form of a linked chain,
or wire rope, or rope of hemp, manilla or the like) by means of the lever a, toggle

page_text: link
9, spring k, and sliding collar j. constructed,, arranged and operating sub-
stantially as herein before described with reference to Figs. 1, 2 and 3 of the
accompanying drawings.
2. The modified method in which the,. coil is opened and closed by means of a
rocking shaft such as a' in connection with cranks such as g', and g², sliding collar j,
spring, link 1, and ring m, constructed, arranged and operating substantially as
herein before described with reference to Figs. 4 and 5 of the accompanying
drawings.
3. The method of closing a coil by means of a continuation of the tail carried
over a pulley a² and attached to the sliding collar, as herein before set forth and
shown at Fig. 6 of the drawings.
4. The method of causing a coil to grip a boss such as el capable of being
expanded, the gripping action being effected by a conical collar, or by other
suitable means, acting upon the boss to expand it, as herein before described with.
reference to Figs. 7 & 8 of the appended drawings.
5. The use, for the purpose of controlling the gripping action and release of a
coil such as b, of a conical bush such as e², constructed and arranged with reference
to the coil. and the casting c², to which the coil is secured, so that relative end
movement of the parts along the shaft causes the coil to bind on an increased
diameter of the bush, as herein before set forth with reference to Figs. 9 & 10 of
the accompanying drawings.
6. Means for opening & closing a coil such as b, consisting of the lever a,
link 1, ring m, spring k, and sliding collar j, constructed, arranged and operating
substantially as herein before described with reference to Figs. 11-12 and 13 of
the drawings.
7. Means for putting a coil into and out of action to cause it to open or close,
said means consisting of a bush 9 and crank rod t, constructed, arranged and
operating substantially as lierein before described with reference to Figs. 11, 12
and 13 of the accompanying drawings.
D
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