Improvements in Friction Clutches.
Year: 1897

page_text: Improvements in Friction Clutches.
We, JAMES REGINALD CHURCHILL and FREDERICK GEORGE SEELEY, both of 9,
London Street, in the City of London, Engineers, do hereby declare the nature of
this invention to be as follows:-
This invention has reference to improvements in friction clutches of the kind
described in the Specification of our former Letters Patent No. 11788 dated June
24, 1892 for connecting and disconnecting rotatable bodies such as shafting, pulleys
and the like. In an arrangement that is suitable for connecting and disconnect-
ing a continuously rotating pulley and a shaft, the clutch comprises an internally
coned drum which is loosely mounted on the shaft to be driven and which has
keyed on its boss the driving pulley. Within this drum is arranged an exter-
nally coned drum that is mounted so as to slide endwise along a sleeve keyed upon
the shaft but is rotated therewith by means of driving pins which project from a
Hange on said sleeve through apertures in the said externally coned drum. The
coned surfaces of the drums are forced into contact and the pulley and the shaft
thus connected by means of springs arranged between the flange of the sleeve and
the inner coned drum, which springs tend to force the drum away from the flange
unless they be compressed by means of suitable striking gear. Such an arrange-
ment may be used for coupling together two shafts in which case the internally
coned drum is fixed to the continuously running shaft. In some cases suitable
striking gear comprises a couple of rings loosely mounted on the flanged sleeve
between a collar fixed thereon and the inner cone; to one of these rings there is
pivoted at each side an eccentric and the straps of the two eccentrics are pivoted
to the other ring. The eccentrics are fixed to the arms of a forked lever by
means of which they can be turned so as to move the rings apart and thus dis-
connect the pulley and shaft, or so as to draw the rings together and thus allow
the springs to bring the clutch surfaces into contact and so connect the pulley and
shaft.
We prefer to so arrange the striking gear that when the pulley and the shaft
are disconnected, the centre of the eccentric lies just on the opposite side of the
plane containing the axes of its pivot and that of its strap to that on which it lies
when the parts are disconnected; suitable stops are provided to prevent the con-
tinued movement of the eccentric, and the springs thus serve to lock the gear in
position.
In a modified arrangement the inner externally coned drum is keyed on the
continuously rotating shaft and is surrounded by a corresponding internally
coned ring that is rigidly connected by bolts, which pass through the flange of the
sleeve keyed to the other shaft, to a disc or ring that can slide along the said
sleeve and between which and the sleeve the springs are located. When the
springs are released by the striking gear they force the sliding disc or ring
away from the flange of the sleeve and the internally coned ring is drawn into

page_text: contact with the externally coned drum by means of the bolts, which may also
serve as driving pins.
In some cases in place of the eccentric striking gear herein before described, a
modified arrangement may be employed in which to opposite sides of each of the
rings that are loosely mounted between the movable cone and a fixed collar on the
sleeve are pivoted the free ends of two pairs of toggle links. The links which are
pivoted to one ring are provided with arms so as to form bell crank levers; the
arms are connected together and linked to the arm of a rock-shaft carried in
bearings attached to the other ring, the arrangement being such that on turning
the rock shaft the toggle links will cause the rings to approach or recede from
each other, as desired. The rock shaft may be of any convenient length to enable
it to be operated from the required position. It is preferably fitted with a hand
lever, that is loosely pivoted to it and is fixed in any required relative position by
a bolt passing through it and one of a number of holes in a disc keyed to the
shaft. In a modified arrangement the toggle links move radially to the axis of
the shaft and one link of each pair is fixed to a laterally extending shaft having
an arm that carries a pivoted nut; in these nuts there works a right and left
handed screw, fitted with an operating hand wheel. In cases where it is neces-
sary to mount the striking gear upon the continuously rotating shaft, upon the
flanged sleeve that is keyed to said shaft, we loosely mount another flanged sleeve,
the movable cone is carried by the driving pins projecting from the flange of
the first mentioned sleeve and the springs are located between the flange of the
secondly mentioned sleeve and a flanged collar, whose flange abuts against the
cone, whilst its body part projects slightly beyond the same so that the adjacent
ring of the striking gear must release the cone from the pressure of the springs
before moving the cone itself out of contact with its fellow. It will thus be seen
that while the frictional surfaces are in contact there will be no thrust on the
striking gear and that whilst they are out of contact the thrust will be between
the striking gear and the loosely mounted flanged sleeve. In connection with two
speed and reversing gears we employ the following arrangement. Upon the shaft
to be driven is keyed a sleeve having at each end a flange through which pass
bolts whose outer ends screw into externally coned drums and whose inner end
portions are encircled by springs arranged between the flanges and bolt heads su
as to tend to draw the externally coned drums towards each other. At each end of
the sleeve there is loosely mounted upon the shaft an internally coned drum,
whose frictional surface surrounds that of the corresponding externally coned
drum. The coned drums are so relatively arranged that the frictional surfaces
of either pair of drums may be in contact, or the frictional surfaces of both pairs
may be out of contact, but that the frictional surfaces of both pairs cannot be in
contact at the same time. To enable the frictional surfaces of one pair of drums
to be moved towards each other whilst those of the other pair are moved apart,
there are interposed between each end flange of the sleeve, pairs of toggle links,
the knuckles or joints of which are connected by links or levers to projecting
portions of a sliding collar mounted on the flanged sleeve, said projecting por-
tions passing through apertures in the flanges. The said collar is grooved and
is shifted by means of a forked lever. When the frictional surfaces of one pair of
drums are out of contact, the levers belonging to that pair and connecting the
toggle links with the sliding collar are approximately at right angles to the axis
of the shaft and the tendency of the springs is to lock the parts in this position.
It is found desirable in order to enable the frictional surfaces of the one pair of
drums to be moved quite clear of each other after those of the other pair have
come into contact, to allow one of the toggle links a slight amount of play, for
instance, by elongating the hole through which the pivot passes, or by mounting
its pivot on a lever whose movement in one direction is limited by means of a
suitable stop. If desired one toggle link of each pair may be in the form of a
bell-crank lever and connected to the sliding collar by another link.
For the purpose of equalizing the pressure on the toggles and thus preventing

page_text: jambing or irregular working of the clutch, in arrangements of this kind in
which radially moving toggles are arranged on opposite sides of the shaft the
links or levers that connect the knuckles or joints of the toggles to the sliding
collar are forked and the ends of the arms of each lever are pivoted to a pair of
plugs adapted to slide in transverse apertures formed through projecting portions
of the collar, the arrangement being such that on the pressure on one toggle
becoming greater than on the other, the plugs will be caused to slide through
their apertures and so transmit the pressure to the other toggle. Instead of the
levers being forked, four toggles arranged in pairs, the toggles of each pair
being directly opposite each other, may be employed; a pair of straight links
or levers connect the knuckles of opposite toggles with the two ends of the sliding
plug that is in line with them.
In small clutches with springs arranged as above mentioned, it is found that
excessive pressure has to be applied to the springs through the striking gear in
order to move the frictional surfaces clear of each, owing to the necessarily short
length of the springs employed. To obviate this disadvantage we arrange the
toggles in pairs as just described and connect the knuckles or joints of each pair.
by means of a spring adapted to straighten out the toggles, when released by the
striking gear, and thus bring the frictional surfaces into contact. The springs
may be either tension or compression springs, the toggles being arranged with their
knuckles further apart or nearer together than their pivots as the case may be.
In another arrangement the disadvantage referred to is also obviated by forming
the sliding plugs to which the connecting links or levers are connected in two
parts and interposing between them a spring, the frictional surfaces being so
arranged that as the toggles are straightened out by the movement of the sliding
collar the frictional surfaces are brought into contact, the spring between the two
parts of the plug being compressed after the surfaces have come into contact.
With this arrangement, the interposed spring enables the collar to be moved to
such an extent that the connecting link will be moved into and slightly beyond
the perpendicular attitude and the clutch will thus be locked in its active position
without pressure being put upon the striking gear. To enable adjustment of the
connecting links or levers with relation to the interposed spring to be effected,
one of the part plugs is formed with a screw threaded part by means of which it
can have its length increased or reduced as required. Tension springs are pro-
vided between the flange of the sleeve and the movable cone drum for the purpose
of drawing the frictional surfaces apart when released by the striking gear.
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We, JAMES REGINALD CHURCHILL and FREDERICK GEORGE SEELEY, both of 3,
London Street, in the City of London, 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:-
This invention has reference to improvements in friction clutches similar to those
described in the Specification of our former Letters Patent No. 11788 dated
June 24, 1892 for connecting and disconnecting rotatable bodies such as shafting,
pulleys and the like as we shall now describe with reference to the accompanying

page_text: illustrative drawings wherein Fig. 1 is a sectional side elevation, Fig. 2 an end
elevation and Figs. 3 and 4 detail views showing one arrangement of friction clutch
according to this invention suitable for connecting and disconnecting a con-
tinuously rotating pulley and a shaft to and from each other.
In this arrangement 1 is the shaft to be driven and which carries a continuously
rotating pulley (not shown) keyed to a boss 2 of one of the clutch members
which is loosely mounted on the said shaft and is held in position in one direction
by a fixed nut or collar 3. The clutch comprises an internally coned drum G
which is loosely mounted on the shaft 1 being for this purpose connected to the
boss 2. Within the drum 6 is arranged an externally coned drum 7 which is
mounted to slide endwise along a sleeve 8 keyed upon the shaft 1 but is adapted
to be rotated with such sleeve by means of driving pins 8* which project from a
flange 8b on the said sleeve through apertures in the said externally coned drum 7.
The coned surfaces of the drums 6 and 7 are forced into contact, and the pulley
and the shaft thus connected, by means of springs 9 arranged between the flange Sh
of the sleeve 8 and the inner coned drum 7, which springs tend to force the said
drum 4 away from the flange 8b unless they be compressed by means of suitable
striking gear. Such an arrangement may be used for coupling together two shafts
in which case the internally coned drum 6 is fixed to the continuously running
shaft.
The arrangement of striking gear shown in Figs. 1 to 4 inclusive comprises a
couple of rings 10, 10" loosely mounted on the flanged sleeve 8 between a collar S
fixed thereon and the inner cone 7; to one of these rings viz. 10° there is pivoted
at each side an eccentric 10b, and the straps and rods 10° of the two eccentrics are
pivoted to the other ring 10. The eccentrics are fixed to the arms of a forked
lever 101 by means of which they can be turned so as to move the rings 10, 10"
apart and thus disconnect the pulley and shaft, or so as to draw the said rings
together and thus allow the springs 9 to bring the clutch surfaces into contact
and so connect the pulley and shaft.
We prefer to so arrange the striking gear that when the pulley and the shaft
are disconnected, the centre of each eccentric 10b lies just on the opposite side of
the plane containing the axis of its pivot and that of its strap and rod to that on
which it lies when the parts are connected; suitable stops 10° and 10 are provided
on the eccentric 10b and eccentric rod 10° respectively to limit the movement of
the eccentrics, and the springs thus serve to lock the gear in position.
Figs. 5 and 6 are respectively sectional side and end views showing a modified
arrangement in which the inner externally coned drum 7 is keyed onto the con-
tinuously rotating shaft 1 and is surrounded by a corresponding internally conel
ring which is rigidly connected as by bolts 8 passing through the flange Sb of
the sleeve 8 to a disc or ring Sd that can slide along the said sleeve 8 and between
which and the said flange 8b, the springs 9 are located. When the springs are
released by the striking gear, they force the sliding disc or ring Sd away from the
flange 8 of the sleeve and the internally coned ring 6 is thereby drawn into con-
tact with the externally coned drum 7 by means of the bolts 8ª, which may also
servo as driving pins. The sleeve 8 in this example is shown as forming the boss
of a pulley that is to be driven by the shaft 1, but the same arrangement can
also serve for driving one shaft from another, in which case the sleeve 8 would
be keyed onto the shaft to be driven. The striking gear, not shown, may be
similar to that shown in Figs. 1 to 4, or one of those hereinafter described with
reference to Figs. 7 to 11 inclusive and is mounted on the sleeve 8 between the
collar 8 and the ring Sd.
a
Fig. 7 is a side elevation partly in section and Fig. 8 an end view, showing
modified arrangement of striking gear, the gear being shown in its operative
position. Fig. 9 is a part side elevation showing the gear in its inoperative
position. In this arrangement to opposite sides of each of the rings 10, 10" that
are loosely mounted between the movable cone and a fixed collar on the sleeve S,
as in the other examples hereinbefore described, are pivoted the free ends of two

page_text: pairs of toggle links 10%. The links which are pivoted to one ring (10) are pro-
vided with arms so as to form bell crank levers and the arms are connected
together and linked by means of links 10% to an arm 10° of a rock shaft 10 h
carried in bearings 10* attached to the other ring 10%, the arrangement being such
that on turning the rock shaft, the toggle links 10' will cause the rings to approach
or recede from each other, as desired. The rock shaft may be of any convenient
length to enable it to be operated from the required position. It is preferably
fitted with a hand lever 10 that is loosely pivoted to it and is fixed in any required
relative position by a bolt passing through it and one of a number of holes in a
disc 10 keyed to the shaft 10h.
Figs. 10 and 11 show a modified arrangement in which the toggle links 10'
move radially to and from the axis of the shaft 1 and one link of each pair is
fixed to a laterally extending shaft 10% having an arm 10' that carries a pivoted
nut 10 in these nuts there works a right and left handed screw spindle 10"
fitted with an operating hand wheel 10%.
In cases where it is necessary to mount the striking gear upon the continuously
rotating shaft, upon the flanged sleeve S that is keyed to the said shaft we loosely
mount another flanged sleeve 8° as shown in the modified arrangement illustratel
in Figs. 12 and 13. This sleeve 8 is provided with collars 8 and 8* A collar
Se fixed to the sleeve 8 retains the sleeve 8e in place endways. The movable
cone 7 is carried by the driving pins 8 projecting from the flange 8b of the
sleeve 8 and the springs 9 are located between the flange 8 of the sleeve Se and
a flanged collar 8h, whose flange abuts against the cone 7 whilst its body part
projects slightly beyond the same, as shown, so that the adjacent ring of the
striking gear (not shown) must, when being moved into its operative position,
relieve the cone 7 from the pressure of the springs 9 before moving the cone itself
out of contact with the adjacent cone 6. It will thus be seen that while the fric-
tional surfaces are in contact, there will be no thrust on the striking gear and that
whilst they are out of contact the thrust will be between the striking gear and
the collars 8 and 8h on the loosely mounted flanged sleeve 8°.
In connection with two speed and reversing gears, we employ an arrangement
of the kind shown in Figs. 14 and 15 by sectional side and end views respectively.
Upon a shaft 1 is keyed a sleeve 11 having at each end a flange 11ª which may be
in the form of an arm as shown, or of a disc and through which pass bolts 11b
whose outer ends screw into externally coned drums 12 and whose inner end por-
tions are encircled by springs 11° arranged between the flanges and bolt heads so
as to tend to draw the externally coned drums towards each other. At each end
of the sleeve there is loosely mounted upon the shaft an internally coned drum 13
whose frictional surface surrounds that of the corresponding externally coned drum.
The coned drums 12 and 13 are so relatively arranged that the frictional surfaces
of either pair of drums may be in contact, or the frictional surfaces of both pairs
may be out of contact, but that the frictional surfaces of both pairs cannot be in
contact at the same time. To enable the frictional surfaces of one pair of drums
to be moved towards each other whilst those of the other pair are moved apart,
there are interposed between each end flange 11ª of the sleeve 11, pairs of toggle
links 14, the knuckles or joints of which are connected by links 14" (or it may be
by levers) to projecting portions 15ª of a sliding collar 15 mounted on the flanged
sleeve 11. The said collar 15 is grooved and is shifted endways by means of a
suitable forked lever as well understood. When the frictional surfaces of one
pair of drums 12 and 13 are out of contact, the links 14ª (or levers) belonging
to that pair and connecting the toggle links 14 with the sliding collar 15 will be
nearly at right angles to the axis of the shaft 1 but to the outer side of a vertical
line so that the tendency of the springs 11° is to lock the parts in this position.
It is found desirable in some cases to enable the frictional surfaces of the one
pair-of drums to be moved quite clear of each other after those of the other pair
have come into contact, for which purpose one of the toggle links is allowed a
slight amount of play, for instance, by elongating the hole through which its

page_text: pivot passes, as shown at 14b, Fig. 16, or by mounting its pivot of a lever or
link 14 whose movement in one direction is limited by means of a suitable stop 14
as shown in Fig. 17. If desired, one toggle link of each pair may be in the form
of a bell-crank lever 14* and be connected to the sliding collar 15 by another
link 14 as shown in Fig. 18.
For the purpose of equalizing the pressure on the toggles 14 and thus prevent-
ing jambing or irregular working of the clutch in arrangements of this kind in
which radially moving toggles are arranged on opposite sides of the shaft, the
links 14 (or levers 14) that connect the knuckles or joints of the toggles to the
sliding collar 15, may be pivoted to a pair of plugs 14 (as shown in Fig. 19)
adapted to slide in transverse apertures formed through projecting portions 15" of
the collar 15, the arrangement being such that on the pressure on one toggle
becoming greater than that on the other, the plugs will be caused to slide through
their apertures and so transmit the pressure to the other toggle.
In small clutches with springs arranged as above mentioned, it is found that
excessive pressure has to be applied to the springs through the striking gear in
order to move the frictional surfaces clear of each other, owing to the necessarily
short length of the springs employed. To obviate this disadvantage we employ
springs arranged to put pressure on the frictional surfaces through the medium
of the toggles themselves. For this purpose we arrange the toggles in pairs and
connect the knuckles or joints of each pair by means of a spring adapted to bring
the frictional surfaces into contact when released by the striking gear. The
springs may be either tension or compression springs, the toggles being arranged
with their knuckles further apart or nearer together than their pivots as the case
may be. In Fig. 19 14 shows a tension spring arranged for this purpose, two
springs being employed so as to give an equal pull on each side of the links 14".
In another arrangement the disadvantage referred to is also obviated by inter-
posing between the sliding plugs 14' to which the connecting links 14° (or levers)
are connected, a spring 148 (as shown in Fig. 20) the frictional surfaces being so
arranged that as the toggles are straightened out by the movement of the sliding
collar 15, the frictional surfaces are brought into contact, the spring 148 between
the two parts of the plug being compressed after the surfaces have come into
contact. With this arrangement, the interposed spring 14 enables the collar 15
to be moved to such an extent that the connecting link 14" will be moved into
and slightly beyond the perpendicular attitude and the clutch will thus be locked
in its active position without pressure being put upon the striking gear. To enable
adjustment of the connecting links 14" (or levers) with relation to the interposed
spring 148 to be effected, one of the part plugs may be formed with a screw
threaded portion by means of which it can have its length increased or reduced
as required. Tension springs may be provided between the flange 11" of the fixed
sleeve 11 and the movable cone drum 12 for the purpose of drawing the frictional
surfaces apart when released by the striking gear.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
-
1. In a friction clutch, striking gear for engaging and disengaging the members
of the clutch comprising a pair of eccentrics pivoted to opposite sides of one
member or part and the straps of which are pivoted to the other member or part,
and a lever connected to the said eccentrics, the arrangement being such that by
partly turning the eccentrics by means of the said lever the members or parts of
the clutch can be engaged with or disengaged from each other according to the
direction of movement of the lever substantially as described.
2. For engaging and disengaging the members of a friction clutch, striking
gear constructed, arranged and operating substantially as herein before described
with reference respectively to and shown in Figs. 1 to 4 inclusive; in Figs. 7, 8
and 9, and in Figs. 10 and 11 of the drawings annexed.

page_text: 3. The improved friction clutch and striking gear constructed arranged and
operating substantially as described with reference to and shown in Figs. 1 to 4
inclusive, or modified according to Figs. 5 and 6, or Figs. 12 and 13 of the draw-
ings annexed.
4. In friction clutches of the kind herein before referred to, the combination with
the movable member of the clutch, of toggles and striking gear constructed and
operating substantially as hereinbefore described with reference to and shown in
Figs. 14 and 15 or modified according to Fig. 16, or to Fig. 17 or to Fig. 18 of
the drawing annexed with or without springs as described with reference to
Fig. 19.
5. The improved friction clutch suitable for use in connection with two speed
and reversing gears, constructed arranged and operating substantially as described
with reference to and shown in Figs. 14 and 15, or modified according to Fig. 16,
or Fig. 17, or Fig. 18 of the drawings annexed with or without springs as described
with reference to and shown in Fig. 19.
6. A friction clutch in which the movable member of the clutch is operated
from striking gear through toggles between which springs are arranged, the toggles
and springs being constructed and arranged substantially as hereinbefore described
with reference to and shown in Fig. 20.
Talad thin 54h
T..1
1000
For the Applicants,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.