IMPROVE- MENTS IN APPARATUS FOR STARTING STOPPING AND REVERSING ROTARY MOTION
Year: 1882

page_text: LETTERS PATENT to Charles Denton Abel of No 28 Southampton Buildings
Chancery Lane in the County of Middlesex for an Invention of "IMPROVE-
MENTS IN APPARATUS FOR STARTING STOPPING AND REVERSING ROTARY
MOTION Communicated to him from Abroad by Franz Reuleaux of Berlin
in the German Empire
"
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 5th October 1882.
CHARLES DENTON ABEL of N° 28 Southampton Buildings Chancery Lane in
the County of Middlesex "IMPROVEMENTS IN APPARATUS FOR STARTING, STOPPING
AND REVERSING ROTARY .MOTION [Communicated to him from Abroad by
Franz Reuleaux of Berlin in the German Empire]
}}
This invention relates to improved apparatus whereby the motion of a shaft,
whether employed for winding apparatus for raising and lowering objects, or for
imparting rotary or rectilinear motion to machinery, can be started, stopped or
reversed at will.
The invention consists mainly in combining with the shaft to be driven a con-
tinuously revolving driving wheel loose thereon, or two such wheels revolving in,
opposite directions, a clutch sliding upon but carried round by the shaft; and screw
gear carried by the shaft for putting the clutch in or out of gear with the wheel or
wheels, the parts being so arranged that by turning the screw gear in one direction
the shaft is made to revolve in one direction while by turning it in the contrary
direction the motion of the shaft is reversed, and by stopping the motion of the,
screw gear the motion of the shaft is also stopped.
According to one arrangement for carrying out the invention more particularly
applicable for raising and lowering objects, the shaft has a winding drum or other
mechanical device, such as a pinion in gear with a rack, by means of which the
objects are raised and lowered, and the before mentioned clutch apparatus is put in
gear with the revolving wheel by means of a screw spindle screwing into the one.

page_text: end of the shaft and connected to the clutch in such a manner that on turning the
screw in one direction the clutch is slid on, the shaft so as to gear with the wheel
by frictional contact, thereby causing the shaft to revolve with the wheel and to
raise the load, the screw spindle continuing to revolve with the shaft and clutch,
after it has slid this in gear. If now the rotation of the screw spindle is stopped, either
by hand or by applying a brake thereto with moderate pressure, then as the shaft
and coupling will still continue to revolve by reason of the frictional contact of the
latter with the wheel, the screw spindle will be screwed backwards relatively to
the shaft, and will thus slide the coupling out of gear with the wheel. The shaft
boing now free, the load suspended therefrom will tend to descend and turn the shaft
in the contrary direction, but as soon as the shaft begins to turn, the screw spindle
being still held stationary, this will be again screwed forward and will cause the
clutch to come in frictional contact with the wheel, thereby stopping the backward
motion of the shaft and tending to turn it forward again. But this forward motion
will be again stopped by the first described action of the screw, and the result
will be that the frictional contact between the clutch. and the wheel will be
maintained at such a degree as just to balance the tendency of the load to turn the
shaft backwards, and consequently the shaft and load will remain stationary.
If on the other hand after turning the screw backwards so as to withdraw the
clutch from the wheel sufficiently to leave the shaft free to be turned backwards
by the load, the backward motion of the screw be continued sufficiently to keep
the clutch out of gear, the shaft will turn allowing the load to descend, the speed
of such descent being capable of regulation by keeping the clutch more or less in
contact with the oppositely revolving wheel. The screw spindle is provided by
preference with differential threads so as to insure great nicety of movement of the
clutch by its rotation.
According to another modification, applicable more particularly for simultaneously
raising or lowering two different loads such as a full and an empty bucket in a
mine, but which is also applicable for stopping starting and reversing rotary or
rectilinear motion generally, the shaft has two drums on which the hauling ropes
are oppositely wound, so that the revolution in either direction will cause one
bucket or load to descend and the other to ascend. The shaft has also two loose
wheels, caused to revolve continuously in opposite directions by any suitable known
means, such as by a pinion on a driving shaft gearing with the one wheal and also
with a second pinion which in its turn gears with the second wheel. The friction
clutch is situated between the two wheels and is actuated by the screw gear
through a rod in the tubular end of the shaft connected to the clutch by a
crosshend passing through slots in the shaft.
According as the one bucket or the other requires to be raised, the clutch is made
to gear with the one or the other toothed wheel, and the screw gear is manipulated
in precisely the same manner as above described for starting, stopping or reversing
the motion.
In both the above arrangements the ascending bucket may be automatically
stopped at a certain point by causing it to come in contact with a lever, the
movement of which applies the break to the screw gear so as to arrest its rotation
as above described.
According to another modification more particularly suitable for starting, stopping
and reversing revolving shafting, or reciprocating parts of machinery driven theruby,
the same combination of parts is employed as last described, but in place of a
frictional clutch a toothed clutch is employed, so that whion this is in the middle
position, out of gear with both wheels, the motion is stopped, the reversal of
motion being in this case effected by throwing the clutch out of gear with the one
wheel and into gear with the other one. This roversal of motion may be effected
automatically by causing a tripping lever or pawl to come into gear with a toothed
wheel on the reversing scrow and turn it so as to throw tho clutch over from one
position into the opposite one when the shaft has made a certain number of
revolutions or when the reciprocating part has travelled a certain distancē.
.

page_text: In all the above arrangements, where considerable power is required, for actuating
the screw gear for starting stopping and reversing the apparatus, such screw gear
may itself be operated by a small auxiliary starting stopping and reversing
apparatus of similar construction: Although I have spoken of screw gear in all
the above arrangements for actuating the clutch apparatus, it will be evident that
any equivalent devices such as cam surfaces or grooves may be employed in lieu
thereof
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Denton Abel in the Great Seal Patent Office on the
4th April 1883.
4
CHARLES DENTON ABEL of N° 28 Southampton Buildings Chancery Lane in
the County of Middlesex "IMPROVEMENTS IN APPARATUS FOR STARTING STOPPING
AND REVERSING ROTARY: MOTION A communication to me from Abroad by Franz
Reuleaux of Berlin in the German Empire
"
i
This invention relates to improved apparatus whereby the rotary motion of a
shaft, whether employed for winding apparatus for raising and lowering objects; or
for imparting rotary or rectilinear motion to machinery, can be started, stopped or
reversed at will.
.
The invention consists mainly in combining with the shaft to be driven a
continuously revolving driving wheel or pulley loose thereon, a clutch sliding upon
but carried round by the shaft, and screw gear or equivalent device carried by the
shaft for putting the clutch in or out of gear with the wheel or pulley, the parts
being so arranged that by turning the screw gear in one direction the shaft is
made to revolve in one direction, while by turning it in the contrary direction the
motion of the shaft is reversed, and by stopping the motion of the screw gear the
motion of the shaft is also stopped.
.
The accompanying drawing shews at Fig 1 a longitudinal section of the
apparatus as adapted to the raising and lowering of a load, in mines and other
localities. The toothed wheel a which is continuously rotated in one and the same
direction either by gearing as at for by hand or any other convenient power, runs
loose upon the shaft c, bearing against a fixed collar at 1 thereon; the clutch
disc b slides with its boss b' longitudinally on the shaft c at the point 3, but is
caused to revolve therewith by a feather and groove or by other means, and it is
capable of being geared with the wheel a by frictional contact at 2, its movement
to and from a for this purpose being effected by means of the screw gear d
screwing with differential threads through the boss of b at 5 and into the end of
the shaft c at 4. On the shaft c is fixed a winding drum c¹ by means of which a
load L can be raised or lowered.
The wheel a being rotated continuously in one and the same direction, namely
in that direction which corresponds to the raising of the load L, such raising of "L

page_text: will take place so soon as the clutch bis in gear. The screw gear dis in this case
shown as a differential screw as before stated, with small difference of pitch, the
two threads being in such a direction that the hand wheel d fixed thereon has to bo
turned in the same direction as a when the clutch is to be put in gear. In order
to secure the position of the wheel after the clutch has been disengaged, being
then at rest, a brake is usually applied to the wheel as indicated at c. This
is connected with the framing e and prevents the rotation of d by moderato
friction at 6.
The mechanism thus arranged is suited for accomplishing the above mentioned
objects. If the load is to be raised, the stopping wheel d' is rotated in the same
direction as a, so that the clutch bis pressed against a with sufficient force to
cause the coupling and shaft to be carried round by a by reason of the frictional
contact at 2; and tho hauling rope is wound up on the drum c. If the load is to
be stopped, the wheel d' only has to be prevented from rotating. In consequence
hercof the parts and b which are still in motion, screw back on the screw.
4, 5, the parts of the female screw threads 4 and 5 contained therein, during
which time the wheel slides backward on the brake at 6 in an axial direc-
tion. By this means the pressure at 2 will be diminished, but only exactly to
such an extent that there shall be sufficient friction left to prevent the load from
causing the shaft a to revolve in the contrary direction. The frictional surfaces at 2
therefore now act as a brake for keeping the load suspended, the degree of pressure
required for this purpose being automatically determined, whether the load be
great or small, because if this should begin to sink, it puts b and c and consequently
also the female screws 4 and 5 in motion causing the clutch to advance so that the
pressure at 2 will be increased; if on the other hand it begins to rise owing to
the shaft being carried round by a the female screws 4 and 5 will screw themselves
backwards on the screw threads 4 and 5, thereby decreasing the frictional pressuro
at 2: The brake at e prevents the wheel d from being carried round by the
frictional contact of the male and female screw threads. If the frictional surfaces
at 2 are well oiled the automatic regulation takes place so accurately that the load
remains quite stationary; with imperfect lubrication slight oscillations about the
position of rest will take place. If it be desired to let the load descend, the
stopping wheel d' must be turned in the direction of the backward motion of the
shaft c. The shaft then runs backwards 'in general at just the same speed as
the wheel is rotated. For as soon as by the back ward motion of d' the friction
at 2 is sounowhat reduced, the shaft c with clutch disc b, actuated by the load L,
will be caused to move backwards, but by this motion if d' were to be stopped,
the female screws 4, 5, would be screwed forward on their male screws exactly to
the same extent as that to which the screws were released by means of the
backward motion of wheel d. The interrupted. condition of the equilibrium
between the momentum of the friction at 2 and that of the load will therefore be
continually reinstated; that is to say, if the backward rotation of the wheel di be
interrupted, the descent of the load will cease. It will be seen that if the wheel d
be moved gradually from a state of rest, that is, with a less angular velocity thana,
a gradual commencement of motion will take place under sliding contact of the
surfaces at 2, and in the same manner a gradual stopping of the load towards the
end of tlie motion may be effected by means of the gradual motion of the wheel d.
It will be evident that the shaft c may be made simultaneously to raise one load,
such as a filled bucket and to lower a second, load such as an empty bucket, the
apparatus being in that case operated by the difference between the two londs..
The frictional clutch with flat frictional surfaces shewn at Fig. 1 is only shewn
by way of example. In place thereof may be used in some cases a conical friction
clutch, a cylindrical clutch, a belt coupling, or any other frictional device, the
arrangement being in every case such that the part b if moved in one direction
or the other, causes the gearing or throwing out of gear of the clutch. If the
power required for gearing the clutch be small, I employ in place of tlic differential
screw a simple screw as sliewn at Fig 2, which is connected in a rotatable manner
3

page_text: to one of the parts d or b, as here shewn at 5, while the screw thread works in the
other part. If necessary the female thread and male thread may be reversed, so
that the former is connected to d and the latter to a or b. It will be evident that
in place of screw threads, cam surfaces or grooves might be used for effecting the
motion of the clutch. Also, that in place of a toothed wheel a a pulley driven by
belt or chain may be used.
The brake e of, the wheel d may be applied at any other point than the
circumference of the wheel, and the brake pressure may be applied by means
of a weight, a blade spring or by other suitable means. In certain cases. I apply
a safety catch for the screw gear as shewn at ghi Fig 2, which brings it to rest
so as to stop the, motion as soon as the load L has been raised beyond a certain,
point.
Although I have shewn the apparatus as applied to the raising and lowering
of a single load by means of a winding drum, yet it will be evident that it may
also be made to simultaneously raise a load, such as a filled bucket on one drum
and to lower another load such as an empty bucket on a second drum, the motion
of the wheel a being reversed when the notion of the buckets has to be reversed.
It is also applicable not only for raising and lowering a load by other known
mechanical devices, such as by a pinion or worin on the shaft c in gear with a
rack or worm wheel that serves to raise the load, but also for effecting the starting,
stopping and reversing of the motion of machinery whether rotary or rectilinear,
the shaft c being for this purpose geared either to other shafting to be driven, or
to a toothed rack or other mechanism, the continued tendency of the shaft c to
turn backwards being in that case imparted either by a weight L acting on a drum
or pulley L' thereon, or by a wheel on the shaft connected thereto by frictional
contact and rotated continuously in the backward direction by other gearing,
the frictional contact being sufficient to cause the shaft to turn backwards so
soon as it is released from the action of the wheel a. I prefer however to employ.
for this last described purpose the construction hereinafter described.
Fig 3 of the accompanying drawings shews a longitudinal section of another
arrangement of the apparatus, and Fig 4 shews a part cross section of the same.
The shaft c to which rotary motion in one direction or the other requires to be
given, carries loose thereon two. toothed wheels a a² that are made to revolve
continuously in opposite directions thereon at 11 and 111 between fixed collars, such
rotary motion being imparted to them by any suitable mechanism, such as by a
pinion on a continuously revolving shaft f, in gear with the wheel a¹ and with
a second pinion f³ on a separate, shaft which pinion is in gear with the second
wheel a². Between the two wheels is a clutch disc b whose boss b₁ slides
longitudinally upon the shaft at 3 but is carried round therewith by a feather
and groove or other device. This clutch disc has double conical friction surfaces
at 21 and 2, capable of gearing with either one or other of two correspondingly
formed grooves in the wheels a¹ a², according as the clutch is slid in one direction
or the other. This motion is imparted to the clutch by means of a rod 62, sliding
in a hollow in the shaft c and connected at its inner end to the clutch by
means of a crosshead passing through slots in the shaft, while at its outer
end it has a screw thread 4 screwing through a female screw in a bush 5
screwing with a screw thread of slightly less pitch than 4 into a female screw
thread in the end of the shaft c, so that by turning the bush 5 by means of the
hand wheel & the rod 62 will be moved in one direction or the other with a speed
due to the difference of the pitches of the two screw threads. On the shaft c are
fixed two winding drums c c for simultaneously raising and lowering two
loads L L which may either be of different weight, such as a full bucket
or an empty bucket in a mine, or they may be both of the same weight so as
to balance each other. Assuming them to be of unequal weight, then the
raising lowering, and holding them suspended will be effected as follows. The
shaft being driven continuously in the direction indicated by the arrow Fig 3,
then if the clutch 6 be put in gear with the wheel a' the shaft c will be
:
=

page_text: rotated in the direction for winding up the load L' which we will assume to be the
heavier of the two, the screw gear. being carried round with the shaft. If now
it be desired at any point to stop the inotion of the load and hold it suspended, this
may be effected by stopping the rotation of the wheel of the screw gear by the
application of a brake o' tliereto, carried by the framing e. On this stopping the 5
rotation of the screwed bush 5 while b and c are still being carried round by a',
the rod. will be screwed inwards through the bush 5 and the clutch will
consequently be moved out of gear with a. The load L will now tend to make
the shaft rotate in the contrary direction, but in doing so the wheel & and bush 5
being still liefd stationary, the rod b will screw itself outward again bringing the 1
clutch into gear with a' again, thereby causing the shaft to rotato in the direction
for raising the load again. But this motion will be again stopped in the manner
first described, d, being still held stationary, and thus the result will be that the
clutch will act as a brake being held in contact with a to just a sufficient extent
to cause the momentum of friction at 21 to balance the momentum of the load L, 1
which will consequently remain stationary or practically so, the perfect state of
rest being dependent upon the perfect lubrication of the frictional surfaces. The
degree of frictional contact between the clutch and wheel will be automatically
regulated according as the load be greater or smaller, as any increase of the load, in
tending to turn the shaft backwards would advance the clutch towards the wheel
and increase the friction, and vice versu.
If it be desired to lower the load L' or to raise the lighter load L³, this may
be effected in two ways; firstly by turning the wheel d backwards after the
clutch has been thrown out of gear with a so as to keep it out of gear while
the shaft is made to revolve backwards by the downward pull of tlie load. L'; or in
other words, after throwing the clutch out of gear, the wheel & and screw gear may
be allowed to revolve back wards with the shaft. If however it be desired to
control the descent so as to prevent it from taking place too rapidly, the wheel and
screw gear may be turned backwards by hand, so that by retarding its rotation
relatively to the shaft, the clutch will be made to bear with more or less frictional
contact against the wheel a and in thus acting as a brake, retard the rotation of
the shaft. Or the same effect may be produced by applying the brake e¹ to the
wheel & so as to retard or stop its rotation: By thus controlling the motion of the
scrow gear it is also possible to cause the load to commence and terminate its
motion respectively with a gradually increasing and gradually diminishing speed.
Secondly, the descent of the load L' and the ascent of L, whether this be the
lighter or the heavier one, may be effected by turning the hand wheel & and screw
gear backwards until the clutch b is thrown into gear with the wheel a², which, as
before stated, revolves in the contrary direction to a', and consequently will also
cause the shaft to revolve in the contrary direction.
It will bo evident that any other mechanism for effecting the raising and lowering
of the loads may be employed in place of the winding drums cc, such as pinions
or worms on the shaft in gear with racks or worm wheels that actuate the load,
and also that the apparatus may be employed for starting stopping and reversing
rotary or rectilinear motion in machinery instead of for raising and lowering
loads.
In this case the stopping would of course have to be effected by throwing the
clutch b entirely out of gear with the wheels or pullios a a, and the reversing by
throwing it out of gear with the one wheel and into gear with the other wheel.
In place of the frictional clutch arrangement shewn on the drawing, any other
known form of frictional clutch or coupling gear may be employed, or a toothed
clutch arrangement may be used. Fig 5 shows a modified construction in which a
toothed clutch is substituted for the frictional clutch; in this arrangement also the
shaft is shewn as employed for imparting a rectilinear to and fro motion to a
toothed rack g by means of a pinion c¹. The essential parts of this arrangement are
the same as in thic preceding ones, but in place of the frictional surfaces at 2 211
a pair of crown teeth gearing are employed. The putting in and out of gear

page_text: requires comparatively a much smaller pressure than in the above and various other
friction clutches, but on the other hand a much greater shifting of the clutch bis
required. For this reason the screw thread 5 is in this case made of a very quick pitch,
and the thread + has the reverse pitch and is also very quick, so that a sinall rotation.
of d effects a considerable shifting of b. The boss of the wheel d is in this case
formed with the two opposite female screw threads, screwing respectively over the
thread 5 formed on the shaft and the opposite thread 4 formed on the head of the
rod b² that moves the clutch. Instead of the normal screw threads I employ in
some cases other curved grooves and projections, or cam motions for the shifting
of band the putting in and out of gear of the coupling. If the direction of
motion of the rack g is to be changed, the wheel dis stopped and then turned in
the contrary direction. If the motion is to be stopped, d is held stationary and is
then left to itself, inasmuch as the brake e will hold a stationary and thereby keep
the coupling disc b in the middle disengaged position. In cases where the forces
to be transmitted through-the shaft c are always small, I employ in place of the
complete coupling disc b only a sector of the same, of which the teeth can even be
reduced to a single one. The toothed coupling inay also be constructed otherwise
than with crown teeth.
If the reversal of the apparatus, that is, effecting the change of direction of
rotation of c is to take place automatically, I provide the wheel d with a toothed
wheel d¹ as shewn at Fig 6, which is actuated by adjustable trippers g¹ in
connection with the rack g, so as to be turned forward or backwards thereby.
These trippers g' are made elastic so that they are bent by the resistance of the
wheel d due to the frictional resistance of the screw gear and clutch, and then
jerk the wheel beyond its middle position into the opposite one.
Should this
arrangement not be sufficient on account of the resistance of the clutch or from
other causes, I employ tripping devices that are cocked by means of the driving
gear before arrival at the end of the stroke, and are only released at that point so
as to effect the reversing with sufficient power.
In all the above arrangements when the starting, stopping and reversing is
effected by hand and the clutch gear offers too much resistance for convenient
manipulation, the reversal of the wheel ₫ may be effected by an auxiliary
starting stopping and reversing apparatus of the same construction. The same
means may also be adopted when by means of a small force available in a machine
a starting, stopping and reversing apparatus requiring comparatively great force is
to be actuated. In these cases the wheel & which acts directly on the gearing is
turned forwards or backwards or stopped by means of the second starting,
stopping and reversing mechanism, for actuating which only a very small force
will be required. The brake e' is in this case generally only applied to the
auxiliary starting stopping and reversing apparatus.
Having thus described the nature of this invention and in what manner the
same is to be performed as communicated to me by my foreign correspondent
I claim -
First. The construction of apparatus for starting, stopping and reversing rotary
motion, wherein a continuously revolving wheel loose upon the shaft to be driven
is combined with a clutch apparatus sliding upon but carried round by the shaft,
and with screw gear operating the clutch and carried by the shaft, the action of
the screw gear being such that its rotation in one direction causes the clutch to
gear with the wheel and to drive the shaft in one direction, while the rotation of
the screw in the contrary direction frees the clutch and allows the shaft to be
rotated in the contrary direction by means of a suspended weight or load, and the
stopping of the screw causes the shaft to remain stationary, substantially as herein
described with reference to Figs 1 and 2 of the Drawings.
Second. The construction of apparatus for starting stopping and reversing rotary
motion wherein two wheels revolving continuously in contrary directions loose
upon the shaft to be driven are combined with a clutch apparatus sliding upon but
revolving with the shaft and with screw gear operating the clutch and carried by

page_text: the shaft, the action of the screw gear being such that its rotation in one direction
causes the clutch to gear with the one wheel and to drive the shaft in one direction,
while the rotation of the screw in the contrary direction causes the clutch to gear
with the other wheel and to drive the shaft in the other direction, and the stopping
of the screw causes the shaft to remain stationary, substantially as herein described
with reference to Figs 3 to 6 of the drawings.
Third In combination with the arrangement of apparatus set forth in the
preceding claim, providing the shaft to be driven with two winding drums for
alternately raising and lowering and holding suspended two loads, substantially as
herein described with reference to Figs 3 and 4 of the drawings.
In Witness whereof I the said Charles Denton Abel have hereunto set my
hand and seal this fourth day of April in the year of our Lord One
thousand eight hundred and eighty-three.