Improvements in Friction Clutches.
Year: 1896

page_text: Date of Application, 15th Feb., 1896-Accepted, 28th Mar., 1896
COMPLETE SPECIFICATION.
Improvements in Friction Clutches.
I, ROBERT FREDERICK HALL, of "Ferndale," Church Road, Moseley, near the City
of Birmingham, Manufacturer, 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 relates to improvements in the construction of friction clutches for
intermittently communicating motion to machinery from a primary driving shaft,.
and has for its object, a self-contained apparatus.
The clutch consists essentially of a drum-shaped casing having double bearings,
one upon the driving shaft and the other upon a sleeve, whose fore or inner end is
conoidally shaped and, through the medium of rollers sliding up the said coned end,
lifts levers of the first order, and through which, extensible quadrant or semi-
circularly shaped friction segments are pressed up to the inside periphery of the
casing through the medium of knee or toggle levers.
:
Figure 1 of the accompanying drawings represents an elevation of a self-contained
friction clutch constructed according to my invention.
Figure 2 represents a vertical section of the same.
Figure 3 represents a like section as Figure 2, but taken at right angles thereto.
Figure 4 represents a vertical section of the clutch upon the dotted line,
Figure 3, looking from right to left.
Figure 5 represents the extensible impingement segments with the driver and
its boss.
The same letters of reference indicate corresponding parts in the several figures.
of the drawings.
a is a shaft, having made fast upon it by keying, a boss b, provided with a
driver b', engaging, through the shouldered depressions 62, with driving lugs c³, of
extensible impingement sections c, whose outer peripheries c', impinge upon the
inner periphery di, of the hollow casing or drum d, made up of sections d², d³ and
connected together by overlapping meeting edges d', d, whilst the neck do, takes
over the naked shaft a, and the neck d', takes over the circular body e', of a sliding
sleeve or bush e, hence a double bearing for the casing, whose sections are connected
together at their meeting parts by small screws d³.
Now the sliding sleeve or piece e, is annularly channelled at e, wherein a
stud f', of a swinging lever, fulcrumed at f2, to a suitably supported hanger ³,
engages.
The inner part of the sliding sleeve e, is coned at e³, up which the rollers g', at the
outer ends, of levers g, fulcrumed at 3, to brackets carried by the driver b',
travel.
Jointedly connected at ', to each of the said levers g, forwardly of the fulcrum
joints g, are links h, with their outer ends also jointedly connected at 2, to the ends
of toggle or knee levers i, whose outer ends are jointed at i¹, to the adjacent ends c
of the extensible impingement semi-circular or half hoop segments c.
jare coiled springs with their outer ends, connected to the driving lugs c³, and
their inner ends to the boss b. These springs are for the purpose of counteracting
centrifugal force and keeping the segments out of fit with the inner periphery of the
outer casing, and also for the purpose of taking the levers back to the normal
positions for releasing the clutch mechanism.
OPERATION.
.

page_text: and impingement segments are running with the shaft, within the casing, whose
function is also that of a driving pulley; on the handle, being swung from right to
left, then the sleeve e, is moved in the direction of the arrow and its couoidal end e³,
is forced under the roller g' and the levers 9, turned upo the fulcra g and
thereby lifted, and through them, the links h, are forced outwardly and the toggle or
knee levers i, made to approach, more or less, a straight line, whereby the extensible
sections c, are forced outwardly and their outer peripheries brought into intimate
contact with the inner periphery d', of the drum or casing d, hence the gripping or
clutching by frictional adhesion between the whole of the parts, which now bodily
rotate together.
On 'now swinging the lever f, in the reverse direction the sleeve, with its conoidal
fore part, is slid backwards, and the springs, which were formerly distended by the
forcing outwards of the impingement segments into intimate contact with the inner
periphery of the drum now contract and draw the levers and links again into the
normal positions as represented in Figures 2 and 3.
By such an arrangement of levers and links as described, only a short movement
of the operating parts is required in order to effect the necessary contact between the
peripheries for transmitting motion, and the retraction of the parts for releasing the
clutch, and further, by making the clutch self contained, and with a bearing on each
side of the internal mechanismn, the same is rendered dust proof and there are no obstacles
to get in the way of the band should the same slip off the pulley, thus there is no
danger of accidents to workpeople, and further, the double or spread bearing keeps
the clutch permanently in a true position with the clutch mechanism.
The joint pins of the toggle levers may be made excentric, so as to admit of
adjustment of them, or the said levers may be made in two parts and connected
together by a screw pin, which, when rotated effects any adjustment of them which
may be required.
Figure 6 represents the casing of the clutch, formed with or carrying a series of
stepped pulleys, although, if necessary, gearing may be employed in lieu of the said
stepped pulleys.
a is the shaft, d the casing and the stepped pulleys.
Figure 7 represents a modification of my invention, in which two clutches are
employed and actuated by a double cone ended sleeve (shown separately in Figure 8)
and a single lever which is move to right or left as required. When the lever is
moved to the left as in the dotted line 1, it drives right handed, and when placed in
the position indicated by the dotted line 2 it drives left handed, but when the lever
is in the midway position as represented, both of the clutches are out of gear and run
free. The clutch mechanism contained in each casing is alike unto that described in
Figures 1 and 2.
a is the shaft, running continuously through both clutch casings d, k and central
sleeve e, which has an annularly grooved boss e, within the groove of which, the
stud, of the lever f, hung or pivoted at 72, takes. This said sleeve has both ends
coned at e, which left roller ended levers for operating the clutch mechanism
which is enclosed within the casings d, k, which may if necessary, have stepped
pulleys de, k', mounted upon their bosses.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
First. In friction clutches, locating the operating mechanism within a drum ca-ing
having double or spread bearings do, d' which encircle the driving shaft or its
equivalent, substantially as described and set forth.
Secondly. In friction clutches, the means herein described for taking the extensible
impingement segments into and out of contact with the drum for driving and
releasing, substantially as described and set forth.
Thirdly. In friction clutches, the combination with the boss and driver b, b, fast
upan the, shaft a, of roller-ended levers g, links h, and toggle lavers i, jointedly

page_text: connected to impingement segments c, all acting in unison and operated through
the medium of the conoidal end e, of a sliding sleeve e, substantially as described and
set forth.
Fourthly. The general construction, arrangement and combination of the parts of
self-contained friction clutches, substantially as and for the purpose herein described
and set forth.
1
1000
ROBERT FREDERICK HALL,
By Henry Skerrett,
24 Temple Row, Birmingham, Agent for Applicant.