Improvements in Frictional Clutches and Couplings.
Year: 1891

page_text: Date of Application, 14th Feb., 1891
Complete Specification Left, 13th Nov., 1891-Accepted, 19th Dec., 1891
PROVISIONAL SPECIFICATION.
Improvements in Frictional Clutches and Couplings.
We JOHN HAYTHORN and JAMES STUART, of Eastwood Engine Works,
Pollokshaws, in the County of Renfrew, North Britain, Engineers, do hereby
declare the nature of this invention to be as follows, that is to say :-
Our said invention has for its object to improve the construction and action of
frictional clutches and couplings, and especially to provide for the more complete
and efficacious contact of the frictional surfaces, our invention being applicable to
the class of clutches or couplings having cylindrical or nearly cylindrical frictional
surfaces.
In carrying out our invention according to one modification the movable frictional
part consists of five or other convenient number of cylindrical segments connected
or jointed to each other and placed within the cylindrical rim of a pulley. The
seginents are forced into engaging contact with the pulley rim by means of a screw
or wedge or other detail arranged to thrust apart the end segments of the set, and
this thrusting action is transmitted through the segments so that all of them become
forced outwards. The drawing together of the end segments, by the screw or by a
spring or otherwise, causes disengagement. One of the segments is fitted so as to
be capable of sliding radially upon an arm formed on a boss which is keyed on the
shaft, and the pulley or cylindrical rim is made in the same piece with or is fixed to
the wheel or pulley which is to be engaged with the shaft. Or in the case of a
coupling, one part is keyed on one shaft and the other pars on the other shaft.
The pulley rim is made with an inward flange which is of advantage for retaining
lubricant, but inapplicable in many existing kinds of clutch. The engagement or
disengagement is effected by means of a grooved ring or sleeve fitted to slide on the
shaft, and connected to the screw or other part which thrusts out or draws in the
segments. We prefer to employ a screw with right-handed and left-handed
threads; and to provide for adjustment by making the middle of the screw in the
form of a small wormwheel and arranging in gear therewith a small screw which
can be turned when required by means of a key.
Instead of the segments bearing directly against the pulley rim they may bear
on an expansible ring which bears on the pulley rim; or they may be covered with
leather or other frictional material. The segments may be jointed directly to each
other at their contiguous ends, or they may be connected by links, which may be
arranged in various ways. In a convenient end joint half bosses are formed on the
contiguous link ends, and are encircled by rings, by which the withdrawing action
is. transmitted from one to another whilst a pin is placed between the central parts
for transmitting the thrust when being expanded.
According to another modification all the segments are fitted to slide radially on
arms or in grooves or in a boss or centre piece keyed on the shaft, and they are
moved outwards by conical or inclined surfaces on the boss or ring which is movable
along the shaft.
Dated this Thirteenth day of February 1881.
EDMUND HUNT,
Applicants' Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in Frictional Clutches and Couplings.
We, JOHN HAYTHORN, and JAMES STUART, of Eastwood Engine Works,
Pollokshaws, in the County of Renfrew, North Britain, Engineers, 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, that is to say :-
Our said invention has for its object to improve the construction and action of
frictional clutches and couplings, and especially to provide for the more complete
and efficacious contact of the frictional surfaces, our invention being applicable to
the class of clutches or couplings having cylindrical or nearly cylindrical frictional
surfaces.
In our improved apparatus the movable frictional part consists of a number of
cylindrical segments connected to or jointed to each other and placed within the
cylindrical rim of a pulley the segments being forced into engaging contact with
the pulley rim by means of a screw or wedge or other detail arranged to thrust
apart the end segments of the set, and this thrusting action is transmitted through
the segments so that all of them become forced outwards. The drawing together
of the end segments, by the screw or by a spring or otherwise, causes dis-
engagement.
On three accompanying sheets of explanatory drawings are shown various
modifications or examples of our improved apparatus.
On Sheet, 1, Figures 1, 2, and 3, show a first modification, and Figure, 4, a
second.
On Sheet, 2, Figures, 5, to 8, show a third modification, and Figures, 9, 'and' 10,
a fourth. And
On Sheet, 3, Figure, 11, shows a fifth modification, Figures, 12, and 13, a sixth,
and Figures, 14, and 15, a seventh.
In these drawings the same reference letters and numerals 'are used to mark the
same or like parts wherever they are repeated.
а
In the modification shown in Figures, 1, 2, 3, five frictional segments, A 1, A 2,
A3, A4, A5, are arranged within the rim, B, of a pulley, B1, which is loose on
a shaft, C. The shaft, C, has keyed on it a boss, C 1, made with an arm, C'2,
which projects into a socket formed for it in the middle segment, A 3, this segment
being fitted so as to be capable of sliding radially on the arm, C2. In the case of
coupling the boss, C 1, is keyed on one shaft, C, whilst the pulley, B1, is keyed
on another shaft in line with the shaft, C. The pulley rim, B, is made with an
inward flange, B 2, which is of advantage for retaining lubricant, but inapplicable
in many existing kinds of clutch. The engagement or disengagement is effected by
means of a grooved ring or sleeve, D, fitted to slide and turn on the shaft, C, and
connected to the parts by means of which the segments," A, are thrust out or drawn
in. We prefer to employ a screw, E, having right-handed and left-handed threads;
and to provide for adjustment by making the middle of the screw, E, in the form
of a small wormwheel, E1, and arranging in "gear therewith a small tangent
screw, E 2, which can be turned when required by means of a key. The screw, E,
wormwheel, E1, and tangent screw,E2, are enclosed "in" a box formed by two
plates, F, which are bolted together and connected by a pair of links, D 1, to the
grooved ring or sleeve; D. The ends of the screw, E, screw into end pieces, E 3,
which are pin-jointed to the end frictional segments, A 1, A 5.
The segments, A, may be jointed directly to each other at their contiguous ends,
In
or they may be connected by links which may be arranged in various ways.
the couvenient, end joint shown in Figures, 1, 2, 3, half bosses or segmental
bosses, G, are formed on the contiguous link ends, and are encircled by rings, G 1,
F

page_text: by which the withdrawing action is transmitted from one link to another, whilst a
pin, G 2, is placed between the central parts for transmitting the thrust when the
segments are being expanded, the pin, G2, by having its ends riveted securing
caps, G 3, which hold the rings, G 1, in position.
The clutch or coupling shown in Figure, 4, as partly sectioned at right angles to
the shaft, C, is a modification suitable for a large shaft, and is made with two sets
of frictional segments, A, acted upon by two radial arms, C 2, and thrust out or
drawn in by means of two screws, E.
When the clutch or coupling is made for transmitting heavy strains the screw or
screws, E, may be differentially threaded, that is, with the screw threads of the ends
of different pitches.
In the third modification (Figures 5, to 8,) the frictional segments, A, are
connected by links, H, H 1, and for the purpose of adjusting the screw, E, there is
formed on it a disk, E 4, radially grooved on its faces as shown in a fragmentary
section, Figure, 6, the inner sides of the pieces, F, being similarly grooved to
engage with the disk, E 4. When an alteration is required in the adjustment, the
pieces, F, are slackened back to allow the disk, E 4, to be turned to the required
extent, and are then screwed up again. Figure, 8, is a plan of part of the middle
segment, A 3, with one of its connecting links, H, which is shown as turned out,
and as having other parts connected to it also as turned out. The segments, A, are
inade each with two ribs or flanges, J, to which the links, H, H 1, and screw-end
pieces, E 3, are pin-jointed.
In the fourth modification (Figures, 9, 10,) there are three frictional segments, A,
connected by pairs of links, H 1; and the engaging or disengaging is effected by
means of a rack, D3, fixed to the movable ring or sleeve, D, on the shaft, C, this
rack gearing with spur teeth, E 5, on a tube, E 6, formed with right-handed and
left-handed internal screw threads to screw upon external screws, E 7, pin-jointed
to the end segments, A.
Instead of the segments bearing directly against the inside of the pulley rim, B,
the segments or links may bear on an expansible ring or segment forming nearly a
complete ring or half ring, which bears on the pulley rim; or the segments may be
covered with leather or other frictional material.
In the fifth modification. (Figure 11) two nearly semicircular segments, A, are
applied, being connected by a pair of links, H 2, and having connecting links, H 3,
bearing on their inner sides near their ends and at intermediate points. The
links, H 3, are thrust out or drawn in, in the same manner as in the first modifica-
tion. The radial driving arm, C2, acts between the segments which are suitably
shaped to fit it.
In the sixth modification, (Figures, 12, 13) four segments are fitted to slide
radially on arms, C 3, or it might be in grooves in a boss or centre piece, C1, keyed
on the shaft, C; and they are moved outwards by conical or inclined surfaces or
wedges, D4, formed or fixed on the ring or sleeve, D, which is movable along the
shaft.
In the seventh modification (Figures, 14, 15) the outwardly acting wedge, D 4,
is applied to a set of frictional segments, A, jointed together, the wedge acting on
a small block, D5, which is connected to the segments, A, by links, H 4, placed so
as to act as toggle links, a spring, H 5, strained tensionally being applied to draw in
the links when not forced out by the wedge, D4.
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. Constructing and combining the parts of frictional clutches or couplings
substantially as in any of the modifications shown in the accompanying drawings
and hereinbefore described.
2. The arrangement or combination of two or more frictional segments jointed or
linked together and applied within a cylindrical rim forming part of a clutch or

page_text: coupling with means for thrusting the segments outwards, substantially as here:n-
before described.
3. The adjusting device consisting of a tangent screw acting on a wormwheel on
the screw for thrusting out the frictional segments substantially as hereinbefore
described.
4. The jointing of the segments together by means of a pin at the centre of the
joint and rings encircling half bosses on the joint parts of the segments substantially
as hereinbefore described.
5. In a clutch or coupling arranging four or more separate frictional segments to
be movable radially and to be acted upon by wedges on a ring or sleeve movable
along the shaft substantially as hereinbefore described.
6. In a clutch or coupling having a number of connected segments or links
interposing between them and the pulley rim, either a nearly complete expansible
ring or two or more segments substantially as herein before described.
Dated this Twelfth day of November 1891.
EDMUND HUNT,
Applicants' Agent.