IMPROVEMENTS IN OR RELATING TO THE DRIVING OF CENTRIFUGAL MACHINES to be as follows:
Year: 1884

page_text: I, ALEXANDER WATT of 89, Hartington Road Liverpool, in the county of
Lancaster, Technical Chemist do hereby declare the nature of my said invention
for "IMPROVEMENTS IN OR RELATING TO THE DRIVING OF CENTRIFUGAL MACHINES
to be as follows:-
"
This invention relates to further improvements in the matter of driving centri-
fugal machines than those described in the specification of Letters Patent granted
to me on the 13th of June 1883, No 2944, and is designed for use with machines
suspended from a flexible buffer, such as are shown and described in the speci-
fication of Weston's Patent N° 2550 of 1870. Such machines are driven by a belt
pulley fixed on the centre line of suspension, where the oscillation is almost
imperceptible.
In carrying out my invention I drive the machines by forming an electro-motor
in combination with and around the shaft by which it is suspended, and in order
to obviate the difficulty that would arise from the oscillation of the shaft I
substitute for the driving pulley the field magnet or the armature of an electro-
motor, either of which would thus revolve with the shaft. If the magnet were
attached to and revolved with the shaft, the armature would be made stationary
and in the form of a ring encircle the magnet, and vice versa, if the armature were
made fast to the shaft. The armature in either case would be made in the form
commonly known as a Gramme or Paccinotti ring. The commutator may be
suitably placed either on the line of no oscillation, or as near as practicable to
it. The fixed magnet when the armature is attached to the shaft, or the fixed
armature in the case of the field magnet being attached to the shaft, is attached to
the beam from which the centrifugal machine is suspended by means of bolts, and
the fixed magnet may be so arranged that if desired the beam may form a part
thereof.

page_text: COMPLETE SPECIFICATION.
I, ALEXANDER WATT, 89 Hartington Road Liverpool, Lancashire Technical
Chemist do hereby declare the nature of my said invention for IMPROVEMENTS
IN OR RELATING TO THE DRIVING OF CENTRIFUGAL MACHINES 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 further improvements in driving centrifugal machines
beyond those described in the specification of Letters Patent granted to me No 2944
of 1883. It is designed for use with machines whose shafts are suspended from or
supported by a flexible buffer at one end such as are shown and described in
the specification of Weston's Patent No 2550 of 1870 and Day's Patent No 772
of 1874.
Machines of this type are ordinarily driven by means of a belt pulley fixed to
the shaft and placed over or round the point of suspension or support in such a
position that the centre line of the pulley in a horizontal plane will approximately
coincide with the centre line of oscillation of the shaft in the same plane and where
the oscillation is almost nil.
In carrying out my invention I drive the machines by forming an electro motor
in combination with and around the shaft. It consists essentially in substituting
for the driving pulley round the point of least oscillation the field magnet or the
armature of an electro-motor either of which would thus revolve with the shaft.
A method of carrying this out is shown in the drawings.
Figure 1 is a sectional elevation on lines zyx showing the suspended shaft of a
centrifugal machine fitted with electro-motor according to my invention.
Figure 2 sectional plan on line z z.
In these A is the central fixed shaft of the apparatus B bracket or casting from
which the shaft is suspended. C beam or girder to which the bracket B is bolted
or otherwise securely fastened. The shaft A is suspended to the bracket B by
means of an india rubber pad or buffer D, which rests on the seat b of the bracket B
and the weight of the shaft is transferred to it through the metal disc a held in
position by the nut a¹. D¹ is a steel ball on, or hemispherical enlargement of the
shaft A, the upper and lower parts of which oscillate about its centre. The shaft A
is fixed so that it does not revolve and A¹ is the outer revolving shaft which carries
the cage.
To the revolving shaft A¹ is securely fixed by a key a" or otherwise a bracket
or casting E preferably of brass. This bracket carries the circular armature F
which is wound with insulated wire like an ordinary Gramme ring and insulated
from bracket E by the non-conducting insulating material e which is kept in place
by 'the brass ring e' screwed to the bracket E. f is the central iron core of the
circular armature and f¹ the coils of wire enclosing same. G is the field magnet
with poles N and S. The magnet is formed circular encircling the armature F and
is supported in position by means of two uprights H¹ forming the crown of the
magnet screwed or bolted to the iron beam C by which they are connected, or if

page_text: supported from a wooden beam, an iron plate may be placed to connect the
uprights H. The magnet is composed of the two curved pieces h h¹ the pole
pieces N and S and the uprights H. The amount of metal in the core of each of
the curved pieces should be equivalent to what is contained in the two uprights
combined. The oscillation of the shaft whilst it causes little or no lateral move-
ment to the armature does cause a radial movement therein, in order therefore that
Buch movement may not cause actual contact between the armature and the pole
pieces and at the same time provide that the two may be situated close together,
the outer surface of the armature is curved convexly and the inner surface of the
pole pieces is curved concavely, so that the former may move about its centro
without coming in contact with the latter, the pole pieces are each made in twọ
pieces the lower piece N' and S¹ being secured together by means of screws
or bolts. The curved core pieces h h¹ are attached to these, their ends passing into
the pole pieces for some distance as shown by the dotted lines, a screw passing into
them, either from top or bottom securely holds them in position. I, insulating plates
which are fastened by screws to the ends of the pole pieces and prevent the contact
of the coils of wires covering the cores h h¹ with the pole pieces. Each one of
these is also made in two pieces and remains attached to upper or lower part of the
pole piece to which they are screwed, though if desired they may each be formed
in a single piece. N" and S" are curved plates which form the faces of the poles
of the magnet and extend at each side beyond the pole pieces N and S. To remove
the armature the lower halves of the pole pieces are unscrewed and taken off when
the former can be lowered. The upright cores H' are screwed or bolted to the
beam C and insulating plates I¹ inserted between the covering wire and the pole
pieces. J is a commutator supported between the projection j on the bracket E
and the ring or washer and insulated therefrom by the rings of insulating
material i. These are held firmly in position by the nuts k, the commutator in the
position shown revolves with the bracket E and shaft A¹. It should be placed as
near as practicable to the zero line of oscillation, and in such a position as to bo
affected as little as possible by the oscillation of the cage and shaft, K is a washer
supporting the bracket and armaturo fastened by set screws to the shaft A¹ so as
to allow of the removal of the armature and commutator from the shaft, when
required. The coinmutator brushes Laro supported from the pole pieces N and S
by means of the brackets L L which are affixed thereto by screws and insulated
by insulating piecos . The brushes pass through a slot in the holder M and are
held in position by the screws m pressing against them. The brushes lie against
the face of the commutator as shown in dotted lines Figure 2. O are terminals by
which the connections with the dynamo machine are made. The wires coiled on
the different sections of the magnet are connected together so as to lead the current
round the several parts.
It will be unnecessary to describe in detail the operation of the different parts as
that will from the foregoing description and drawings be readily understood by
the electrical engineer.
It will also be understood that by reversing the electrical connections between
the armature and field magnet by well known means the direction of rotation can
bo reversed thus forming an effectual brake.
It will also be understood that by altering the mechanical arrangement and
affixing the armature to the beam, and the field magnet to the revolving shaft, and
causing the magnet to revolve with the shaft the same results will be produced,
but the arrangement and construction shown in the drawings I consider to be the
best.
This invention described for driving centrifugal machines with the driving shaft
susponded at one end from an elastic buffer will also be found applicable for a later
improvement on these machines whose shaft is supported at one end only, namely
those which have the shaft supported at its foot on an elastic buffer or support, and
free to oscillate at the top where the cage or machine is placed, a modification of
the separate parts being only required.

page_text: I wish it to be understood that I do not here make any claim for the fixing of
the shafts of centrifugal machines, nor do I claim broadly the driving of such
machines by electricity as I have already in the specification of my patent previously
referred to described one method of applying electricity for the purpose.
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
1st. The method of driving centrifugal machines whose shaft is suspended or
supported at one end only, which consists in applying to the driving shaft on or
about the zero line of oscillation an electro motor with an annular armature
attached to and revolving with the shaft inside a stationary field magnet or a field
magnet fixed to and revolving with the shaft inside a stationary armature, sub-
stantially as described.
2nd. In substitution for a driving pulley and for the purpose of driving a
centrifugal machine such as is known as Weston's, either suspended from above or
supported from beneath; The combination of an annular armature coiled like a
Gramme or Pachinotti ring, and stationary field magnet or set of field magnets
within which it is caused to revolve, substantially as described.
3rd. The combination with the shaft of a centrifugal machine having a flexible
supporting device of a field magnet, revolving in an annular armature, substantially
as and for the purposes described.
4th. The general arrangement and construction of driving apparatus for centri-
fugal machines, substantially as described and shown.
Dated this 28th day of January 1885,
WP. THOMPSON & Co.,
Of G, Lord Street, Liverpool,
and 323, High Holborn, London,
Patent Agents for the Applicant.