IMPROVEMENTS IN OR RELATING TO THE DRIVING OF CENTRIFUGAL MACHINES "
Year: 1883

page_text: LETTERS PATENT to Alexander Watt of Liverpool in the county of Lancaster
for an Invention of " IMPROVEMENTS IN OR RELATING TO THE DRIVING OF
CENTRIFUGAL MACHINES
"
PROVISIONAL SPECIFICATION left by the said Alexander Watt at the
Office of the Commissioners of Patents on the 13th June 1883..
ALEXANDER WATT of Liverpool in the County of Lancaster
IN OR RELATING TO THE DRIVING OF CENTRIFUGAL MACHINES"
"IMPROVEMENTS
Centrifugal machines or hydro-extractors require to be driven at a high
circumferential velocity, and it is usual to drive them by straps running at a
high speed. The speed being increased from the main shafting by one or more
counter shafts, the straps passing from pulleys of large diameter onto ones of
smaller diameter. Without a complication of machinery such as cone drums or
stepped cone pulleys etcetera, no means can be provided for regulating the speed
of a single centrifugal machine where there are a number working together, and
if the speed of one machine is required at any given time either greater or less
than the average for a special material under operation, it is usual under the.
present system to increase or decrease the speed of the engine, and the whole-
range of the machines go at the altered speed. The numerous driving straps
required are also a source of great trouble and danger, besides occupying much
valuable space.
It is to obviate the necessity for the use of straps for driving centrifugal
machines, and at the same time provide a simple and ready means for regulating
the speed of each single machine as may be required, that this invention is
designed.
To the shaft of a centrifugal machine of ordinary construction, and suspended
from above and free to oscillate within limits at the bottom, I attach an Electro-
motor by means of an elastic joint or swivel joint. This joint may be suitably
made of a block of india-rubber which is perforated so as to form a tube of
considerable strength and thickness. The two shafts are brought nearly close
....מ

page_text: together above the point of suspension of the machine, and the india-rubber block
placed over the end of each and suitably fastened. Instead of india-rubber, the
joint may be made and the shafts coupled by means of a series of springs made
fast in plates which are secured to the shafts or to the shafts direct, or the shafts
may be connected by means of a short piece of flexible shafting consisting of
spirally coiled steel wire.
Where the centrifugal machine is supported below or is pivoted between points
top and bottom, I purpose to transform the machine into an electro-motor by using
the outer casing to support or form the field magnets of the motor, in which case
the revolving drum or basket acts as the armature, or the casing of the machine
may be made the armature and the revolving drum the field magneta. In the
former case I place a series of electro-magnets round the casing either at the top
or bottom, and attach to the revolving drum, which must be constructed of non-
magnetic metal, a number of soft, iron bars to act as armatures to the magnets.
In the latter case I fix a ring armature such as that of Pacinotti or Gramme to the
outer casing of the machine, and in the revolving drum I replace the ordinary
top rim by a ring of soft iron, or by semi-circular rings of magnetised steel
composed of numerous thin plates so placed that similar poles are in contact with
each other. These rings act as the field magnets of motor. I carry the wires
from the field magnets in the first case and the armature in the second case in a
tube to a commutator placed so as to be acted on by the brushes which are fixed
on a convenient part of the shaft.
I propose to drive the machines when several are working together by one
generating Dynamo-electric machine, arranging the centrifugal motors either in
parallel circuits or in series. In the latter case in order to allow of any machine
or machines being started or stopped without affecting the remainder, I join
up a secondary battery of a suitable number of cells to the terminals of each
motor.
To regulate the speed of the centrifugal machines I place in each circuit a
resistance coil of ordinary construction, so that by simply moving or turning a
handle, the speed may be regulated or adjusted at pleasure, or if necessary it could
be so made that the direction of motion might be reversed. By this means the
starting of the machine could be made so gradual that the jarring and wear and
tear consequent upon throwing the belt going at a high speed onto an inert
machine might be avoided.
By these improvements in the driving and regulating of centrifugal machines,
the dangerous overhead belting may be dispensed with, and I estimate that while
still leaving sufficient room to properly attend to each machine, the number of
machines placed in a given space may be doubled or even trebled without causing
inconvenience.
.
Electro motors (not merely of the special design herein described but others
varying widely from it in detail) will be found specially adapted for driving
centrifugal machines, as both motor and machine are most efficient when driven at
a high speed, and I do not bind myself exclusively to the use of the particular
form or forms of motor herein described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Watt in the Great Seal Patent Office on the
13th December 1883.
ALEXANDER WATT of Liverpool in the county of Lancaster
IN OR RELATING TO THE DRIVING OF CENTRIFUGAL MACHINES.'
"IMPROVEMENTS
Centrifugal machines or hydro-extractors require to be driven at a high
circumferential velocity, and it is usual to drive them by straps running at a high
speed, the speed being increased from the main shafting by one or more counter-.
shafts, the straps passing from pulleys of large diameter onto ones of smaller
diameter. Without a complication of machinery such as cone drums, or stepped
cone pulleys, etcetera, no means can be provided for regulating the speed of a
single centrifugal machine where there are a number working together, and if the
speed of one machine is required at any given time either greater or less than the
average for a special material under operation, it is usual under the present system
to increase or decrease the speed of the engine, and the whole range of the machines
go at the altered speed. The numerous driving straps required are also a source
of great trouble and danger, besides occupying much valuable space.
It is to obviate the necessity for the use of straps for driving centrifugal
machines and at the same time provide a simple and ready means for regulating
speed of each single machine as may be required, that this invention is designed.
To the shaft of a centrifugal machine of ordinary construction and suspended
from bearings above and free to oscillate within limits at the bottom, I attach an
electro-motor by means of a flexible or swivel joint. This joint may be suitably
made of a block of india-rubber, which is perforated so as to form a tube of
considerable strength and thickness. The two shafts are brought nearly close
together above the point of suspension of the machine and the india-rubber block
placed over the end of each and suitably fastened. Instead of india-rubber the
joint may be made and the shafts coupled by means of a series of springs made
fast in plates which are secured to the shafts, or to the shafts direct, or the shafts
may be connected by means of a short piece of flexible shatting consisting of
spirally coiled steel wire.
Figs. 1 and 2 show two very simple forms of the flexible joint. In Fig. 1 A is
an india-rubber block shown in section. B shaft of motor. C shaft of centrifugal
machine free to oscillate within certain limits at bottom, the stift india-rubber
joint preventing too great divergence. The india-rubber may be secured to the
shafts by a coil of wire a round each as shown, or by a metal sleeve passed over
it into which the india-rubber is compressed in somewhat the same manner as
shown at A" in Fig 2. Instead of having the two shafts placed close together as
shown in Fig. 1, the blocks of india-rubber may be compressed into cups or sockets
in the ends of the shafts, but in order to prevent oil running down the shaft
and thus coming in contact with the india-rubber, I prefer to form one socket in
the motor-shaft and the other in the connecting link as shown in Fig 2, in which
D is the connecting link and B1 and B¹ sockets into which the india-rubber
blocks A are compressed. These couplings are more suitable for small
machines.
For large heavy rough work the design shown in Fig. 3 will be found good.
In this is shown a modified design of the mode of suspension for shafts used in
what is known as the Weston centrifugal machine and described in specification of
patent No 2550 of 1870. As before A A¹ are india-rubber blocks. Bupper shaft.
Qlower shaft. D intermediate link. The rod D is linked or connected to shafts B.

page_text: and C by forked ends passed into the cup of said B and C with their prongs on
each side of tongues or cottars E El passed through the shafts B and C as shown,
E being placed exactly midway between the india-rubber suspension blocks A A¹.
The motion from shaft B is thus communicated to shaft C through the link or
communicating rod D without carrying any of the vibration from the centrifugal
machine to the motor shaft. The cage of the centrifugal machine is attached to
shaft C, which is suspended from a casing F in which it is free to revolve. The
casing is suspended from the hanger F¹ where it rests and is held in position by
the india-rubber blocks A. and A¹. The collar G on shaft C resting on the friction
washer and rings H, sustains the weight of the cage I and material therein, while
the sleeve J of brass or copper prevents vibration in the upper part of the casing F.
To prevent the leakage of oil from around the shaft C passing down the shaft into
the cage, I affix thereto by screwing as shown (or by welding to the shaft) a cup K
which will catch or retain any surplus oil. A second nut K is used to make the
joint more secure.
Where the centrifugal machine is supported below, or is pivoted between points,
top and bottom, I purpose to transform the machine into an electro-motor by using
the outer casing to support or form the field magnets of the motor, in which case
the revolving drum or basket acts as the armature, or the casing of the machine
may be made the armature, and the revolving drum the field magnets. In carrying
out this object I fix a ring armature such as that of Pacinotti or Gramme to the
outer casing of the machine, and in the revolving drum I replace the ordinary
top rim by a circular electro-magnet or by semi-circular rings of magnetized steel
composed of numerous thin plates so placed that similar poles are in contact with
each other. This electro-magnet or the steel rings act as the field magnets of
motor; I carry the wires from the field magnets and the armature in tubes to a
commutator so placed as to be acted on by the brushes which are fixed on a
convenient part of the shaft. I propose to drive the machines when several are
working together by one generating Dynamo-electric machine, arranging the
centrifugal motors either in parallel circuits, or in series. In the latter case in
order to allow of any machine or machines being started or stopped without
effecting the remainder, I take the current from a suitable number of cells of a
secondary battery kept charged by the Dynamo machine.
To regulate the speed of the centrifugal machines, I place in each circuit a
resistance coil of ordinary construction so that by simply moving or turning a handle,
the speed may be regulated or adjusted at pleasure, or if necessary it could be so made
that the direction of motion might be reversed. By this means the starting of
the machine could be made so gradual that the jarring and wear and tear
consequent upon throwing a belt, going at a high speed onto an inert machine
might be avoided.
By these infprovements in the driving and regulating of centrifugal machines
the dangerous overhead belting may be dispensed with, and I estimate that while
still leaving sufficient room to properly attend to each machine, the number of
machines placed in a given space may be doubled, or even trebled, without causing
inconvenience.
Electro-motors will be found specially adapted for driving centrifugal machines,
as both motor and machine are usually driven at a high speed, and I do not bind
myself exclusively to the use of the particular arrangements of motors herein
described.
In Figs. 4 and 5 I have shown a centrifugal machine constructed according to
my invention.
Fig. 4 being a plan with parts removed and
Fig. 5 a sectional elevation.
In these A is the ordinary outer casing of the centrifugal machine, and B the
basket or cage. Ca ring of soft iron with two pole-pieces D D¹ formed each of
two angle pieces fixed together and to the ring by means of screw E, and the
lower angle. piece firmly screwed to the brass projecting rim of the cage B,

page_text: F is a stationary Pacinotti ring, with twelve helices G connected up so as to form
a continuous coil round it separated by soft iron pole-pieces H. I is a commutator
to which the twelve wires from the helices are brought, six of them through one
arm of the tubular bridge-piece J and six through the other. I do not confine
myself to the number twelve, but mention this number only as the actual number
there happen to be in my experimental machine as illustrated. The commutator
can be arranged in any convenient manner, and has one brush connecting the
helices successively with the electric generator, and the other and opposite brush
connecting the opposite helices successively with coil around ring C. The wire
after passing many times round this ring in such a way as to produce poles of
opposite sign at the pole pieces D D passes off to the cage which is electrically
connected with the casing, which in turn is connected with the generator of
electricity. The outer casing A. is preferably composed of three parts, the upper
one fitting on the lower, but capable of being detached at the joint L as shown,
and a cover K placed on top to prevent any material falling into the electro-
magnetic apparatus. L is an annular plate attached to the cage for a similar
purpose. In the machine the basket is suspended or supported at N in the usual
manner in the lower part of the casing. The lower angle pieces or poles D¹ are
permanently attached to the electro-magnet C and the upper angle pieces D are
screwed or otherwise attached to the magnet C so as to be removable. One wire of
the magnet is brought up the central hollow spindle P to the narrow brush
P
which bears on the commutator sections, the other is fixed to the basket which is
in electric connection with the casing and through the terminal T with one pole of
the electric generator. The upper part of the casing with the armature or Pacinotti
ring F, the bridge-piece J and commutator, are next placed in position and the
twelve wires brought from the several helices through the arms of bridge-piece J
and attached in the usual manner to the commutator. The wire from the other
pole of the generator is brought through the terminal T¹ to an insulated plate or
ring on the commutator 9 which is connected to the opposite side of the commutator
by means of the double brush p¹. Both brushes are attached to an insulating
disc which is movable round the spindle but can be fixed in any position by
means of the set screw q¹.
In Fig. 6, sheet 3, is shown in sectional elevation a sketch of an arrangement
specially suitable for the form of centrifugal machine used as a cream separator or
for other such purposes where a drum with solid sides is required. A is the
framework made of soft iron and coiled with wire in connection with &
commutator F, forms an electro-magnet with pole-pieces B. O is the drum of the
machine round which is placed a Gramme ring D the wires from which pass up
the hollow spindle E to a commutator F suitably placed; the arrangement of the
wires is similar to that before described in connection with Figs. 5 and 6.
It will be obvious to all that the two parts of this invention can each be greatly
varied without departing from the main principle set forth. Various arrangements
of electro-magnetic machines in combination with the centrifugal machines could be
used, and the elastic or flexible joint could be made in other ways, some of which
as for instance with a series of springs in lieu of india-rubber have been suggested
in my provisional specification. I have here simply set forth the best means
known to me of carrying into effect the invention which I desire to protect under
the letters patent which consists :-
1st. The arrangement for driving centrifugal machines, which consists in coupling
a separate electro-motor to each separate centrifugal machine by means of a flexible
universal or other joint admitting sufficient play in the basket at the bottom of
the shaft, while the electro-motor shaft is steady in its bearings, substantially as
described, by which it is possible to easily regulate (by means of a resistance coil),
the speed or working of any of a series of centrifugal machines, independently of
the others.
2nd. The joints for connecting the shaft carrying the basket of the centrifugal
machine with the driving shaft, substantially as described.

page_text: 3rd. The combination in one machine of an electro-motor and a centrifugal
machine, substantially as described.
In witness whereof I the said Alexander Watt have hereunto set my hand and
seal this twelfth day of December in the year of our Lord one thousand eight
hundred and eighty three.
ALEXANDER WATT (L.S.)