Improvements in and relating to Friction Clutches.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to Friction Clutches.
I, FREDERICK BRUNT, of Godstone, in the County of Surrey, Mechanical
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates. to that form of clutch for transmitting power where one
portion of the mechanism is keyed permanently upon the power shaft while the
other portion is put into gear or pulled out of gear when desired and it relates
more particularly to the method and apparatus for putting the clutch into and out
of gear. It is specially suitable for clutches transmitting a large horse power
though it may be applied for any desired size.
The invention consists generally in applying to a motor shaft upon which any
form of friction clutch is used a device whereby upon the movement of a small
auxiliary clutch special gearing carried upon and concentric with the motor shaft
is put into operation and driven by the said motor shaft so that the main friction
clutch is caused to bite or seize and so transmit the required power. The inven-
tion further consists in arranging an external brake device whereby a portion of
the said concentric gearing is retarded and made to reverse when it is desired
to pull the main friction clutch out of action.
In carrying the invention into effect according to one modification the procedure
is as follows:-A disc is keyed upon the power shaft having a conical periphery
which bites or grips by friction with a corresponding coned recess formed integral
with a driving pulley loose upon the motor shaft. Bearings are formed in this
loose driving pulley which carry one or more spindles having gear wheels keyed
upon them and these spindles are disposed concentrically around the axis of the
motor shaft. These gear wheels intermesh with a single gear wheel placed loose
upon the motor shaft but attached to a drum pulley and the said drum pulley has
formed upon one side of its boss recesses for an auxiliary jaw clutch while upon the
outer periphery of the drum pulley, grooves or the like are placed, into which
brake blocks or bands may fit. Further along the motor shaft and immediately
adjacent to the recesses in the auxiliary jaw clutch a sleeve riding upon a sunk
key or feather is placed carrying jaws to fit into the recesses in the drum pulley
when laterally displaced. The spindles carrying the concentric gear wheels have
screwed extensions which project into nuts carried in a circular groove formed in
the stationary coned disc and these nuts may be of any shape as long as they pre-
vent lateral movement in the direction of the shafts length.
To throw the clutch into gear the sleeve upon which one half of the auxiliary
jaw clutch is formed is displaced longitudinally by a lever or other device so as to
gear with the other half of the auxiliary jaw clutch formed upon the drum pulley
which carries the small single gear wheel riding upon the power shaft. At this
moment of course the brake block or bands upon the periphery of the drum
pulley are loose or out of gear. The drum pulley at once rotates the central gear
wheel and causes all the gear wheels carried upon the spindles upon the large
driving pulley to rotate and therefore the screwed extensions upon their respective

page_text: ends also to rotate. The rotation takes place in such a direction that the nuts upon
the ends of the extensions simultaneously pull together the driving pulley and the
friction coned surfaces so as to bind or grip the main clutch and therefore cause
the large driving or loose pulley to rotate and transmit the power.
The auxiliary jaw clutch is now put out of action by displacing it backwards to
its first position so that in cases where a permissive drive is required by the clutch
such as is common in collieries, slipping of the driving clutch surfaces can take
place when a given rope tension is exceeded. When it is desired to separate the
main friction clutch the brake blocks or bands are put into operation to bind the
drum pulley and therefore hold stationary the small gear wheel upon the power
shaft. This, of course, at once causes the gear wheels carried by the driving pulley
to rotate in a reverse direction and therefore causes the screwed extensions of the
respective spindles also to rotate and to separate the coned disc and coned recess
formed respectively upon the keyed disc and main driving pulley.
It is to be understood that any form of main friction clutch may be employed
other than the coned surfaces herein before described as it is evident that other well
known types such as the "Weston" disc or with expanding segments, could be
operated by the improved arrangement. Any suitable auxiliary clutch may also
be used instead of the jaw clutch.
This invention provides a simple and effective means whereby a small auxiliary
clutch brings into operation the central gear wheels and causes the power shaft
itself to pull the driving pulley upon the disc and so cause the power being trans-
mitted to put into operation the main clutch. The advantages of this are evident
as but small power is required to displace the auxiliary clutch while by suitably
designing the proportions of the concentric gearing any desired pressure may be
brought upon the main or friction clutches. For this reason clutches of this kind
while suitable for small powers are specially suitable for transmitting large
powers.
1000
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MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
I, FREDERICK BRUNT, of Godstone, in the County of Surrey, Mechanical
Engineer, 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 that form of clutch for transmitting power where one
portion of the mechanism is keyed permanently upon the power shaft while the
other portion is put into gear or pulled out of gear when desired and it relates
more particularly to the method and apparatus for putting the clutch into and out
of gear.
It is specially suitable for clutches transmitting a large horse power
though it may be applied for any desired size.
The invention consists generally in applying to a motor shaft upon which any
form of friction clutch is used a device whereby upon the movement of a small
auxiliary clutch special gearing carried upon and concentric with the motor shaft
is put into operation and driven by the said motor shaft so that the main friction
clutch or box is caused to bite or seize and so transmit the required power. The inven-
tion further consists in arranging an external brake device whereby a portion of

page_text: the said concentric gearing is retarded and made to reverse when it is. desired
to pull the main friction clutch out of action.
In the accompanying sheet of explanatory drawings
Figure 1.is a sectional elevation and
Figure 2 an end elevation of one convenient form of my improved clutch.
In carrying the invention into effect according to one modification the procedure
is as follows: A disc A is keyed upon the power shaft B having a conical peri-
phery which bites or grips by friction with a corresponding coned recess formed
integral with a driving pulley C loose upon the motor shaft B. Bearings are
formed in this loose driving pulley C which carry one or more spindles E E¹ having
gear wheels FF1 keyed upon them and these spindles are disposed concentrically
around the axis of the motor shaft B. These gear wheels FF intermesh with a
single gear wheel G placed loose upon the motor shaft B but attached to a drum
pulley H and the said drum pulley has formed upon one side of its boss recesses h
for an auxiliary jaw clutch while upon the outer periphery of the drum pulley
grooves or the like 2 are placed into which brake blocks or bands may fit. Further
along the motor shaft and immediately adjacent to the recesses h in the auxiliary
jaw clutch, a sleeve K riding upon a sunk key or feather is placed carrying jaws k
to fit into the recesses in the drum pulley when laterally displaced. The
spindles E El carrying the concentric gear wheels have screwed extensions e which
project into nuts L carried in a circular groove A¹ formed in the stationary coned
disc A and these nuts L may be of any shape as long as they prevent lateral move-
ment in the direction of the shaft's length.
To throw the clutch into gear the sleeve K upon which one half of the auxiliary
jaw clutch is formed is displaced longitudinally by a lever or other device so as
to gear or engage with the other half of the auxiliary jaw clutch formed upon
the drum pulley which carries the small single gear wheel G riding upon the
power shaft B.
At this moment the brake block or bands upon the periphery 2
of the drum pulley H are kept loose or out of gear. The drum pulley H at once
rotates the central gear wheel G and causes all the gear wheels F F1 carried upon
the spindles E E¹ upon the large driving pulley C to rotate and therefore the
screwed extensions e upon their respective ends also to rotate. The rotation takes
place in such a direction that the nuts L upon the ends of the extensions simul-
taneously pull together the driving pulley A and the friction coned surfaces a c
so as to bind or grip the main clutch and therefore cause the large driving or loose
pulley C to rotate and transmit the power.
The auxiliary jaw clutch is now put out of action by displacing K backwards
to its first position so that in cases where a permissive drive is required by the
clutch such as is common in collieries, slipping of the driving clutch surfaces a c
can take place when a given rope tension is exceeded. When it is desired to
separate the main friction clutch A C the brake blocks or bands are put into
operation on h³ to bind the drum pulley and therefore to hold stationary the small
gear wheel G stationary upon the power shaft. This, stationary gear wheel then
at once causes the gear wheels F F¹ carried by the driving pulley G to revolve in
a reverse direction and therefore causes the screwed extensions of the respective
spindles also to rotate and unscrew within the nuts L thereby separating the coned
disc a and coned recess c formed respectively upon the keyed disc A and main
driving pulley C.
To reduce the driving strain upon the screwed ends e I sometimes provide pro-
jecting lugs or drivers 2 upon the disc C which engage with the sides of the nuts L.
It is to be understood that any form of main friction clutch may be employed
other than the coned surfaces herein before described as it is evident that other
well known types such as the "Weston" disc or a clutch with expanding segments,
could be operated by my improved arrangement. Any suitable auxiliary clutch
may also be used instead of the jaw clutch and friction instead of toothed gearing
may be employed for actuating the spindle screws. This invention provides a
simple and effective means whereby a small auxiliary clutch brings into operation

page_text: the central gear wheels and causes the power shaft itself to pull the driving pulley
upon the disc and so cause the power being transmitted to put into operation the
main clutch. The advantages of this are evident as but small power is required
to displace the auxiliary clutch while by suitably designing the proportions of the
concentric gearing any desired pressure may be brought upon the main or friction
clutches. For this reason clutches of this kind, while suitable for small powers
are specially suitable for transmitting larger powers.
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 improvements in friction clutches consisting of a supplementary or
initial actuating clutch for controlling the movement of the main clutch friction
driving surfaces substantially as and for the purposes hereinbefore described.
2. In friction clutches the combination of a fixed supplementary driving clutch
with a loose central driving pinion which gears with or communicates motion to
other gear wheels having their fixed spindles mounted in bearings formed within
the main loose driving pulley or clutch box substantially as and for the purposes
herein before described and as illustrated in the accompanying drawings.
3. In friction driving clutches the combination and arrangement of a supple-
mentary driving clutch with a central driven brake wheel and combined gear
pinion for transmitting motion to other wheels gearing with it, whereby the
screwed ends of the spindle of such driven gearing wheels are caused to screw
into or unscrew from nuts which are carried within a circular path formed within
the main driving clutch substantially as hereinbefore described and as illustrated
in, the accompanying drawings.
100
3
1000
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents.