Electro-magnetic Variable Speed Gearing.
Year: 1892

page_text: Date of Application, 31st Mar., 1892
Complete Specification Left, 31st Dec., 1892-Accepted, 11th Feb., 1893:
.1
PROVISIONAL SPECIFICATION.
Electro-magnetic Variable Speed Gearing.
I WILLIAM WORBY BEAUMONT of 100 Palace Road Tulse Hill London
Civil Engineer do hereby declare the nature of this invention to be as follows :—
It relates to the construction of apparatus and gearing for imparting variable
velocity or variable speed of rotation to machinery or to vehicles while the gearing
itself or part of it receives a nominally uniform speed of rotation.
On the spindle of a motor or shaft driven by a motor of any well known kinds, I
fix an electro-magnet or magnets of the disc iron clad or multipolar types the
exciting wires of which are supplied with current from collectors, commutators
brushes or apparatus for distribution, on the said spindles or otherwise conveniently
placed and receiving current from a source, by wires or conductors which are arranged
in connection with switches and shunts either in pairs or three wire systems or
combinations of these. The faces or peripheries of these said magnets, which in the
case of disc or similar form are plain, or are radially or concentrically corrugated
or toothed with a view to obtaining strong frictional grip with small magnetic strength
of pull, may be covered or faced with a non-magnetic medium to avoid effects of
magnetic persistence. The said faces are adjacent to similar or corresponding
faces formed on discs attached to or forming part of the wheels or pinions which
being on the same spindle or adjoining spindle or shaft are to be driven or carried
round by the magnet. These wheels or pinions are of different diameters and gear
with the wheels or pinions of the machinery, apparatus or spindles to be driven
at different speeds. These wheels or pinions may be wholly or partly of non-
magnetic materials such as gun metal or phosphor bronze. The current used for
exciting the magnets may for instance when the apparatus is used for driving
tramway cars or for similar purposes by electro motors be passed through wires
which form part of the motor circuit or may be on separate circuit. The wires
may be so coupled up to the apparatus and to switches and resistances where
required, that the strength of the field of the magnet, or either of the magnets,
may be varied so that the change from the speed from one to another of the
gear wheels and pinions shall not be accompanied by shock, the one gradually
ceasing to have power to drive & the other of the set gradually receiving
enough power.
In some cases the connection between the magnets and the discs on the pinions
of the wheels to be driven may be by means of alternate discs or plates after
the manner of Weston's friction clutch. When the magnet or magnets act.
circumferentially they will be encircled by or will encircle without touching the
parts they drive as in or after the manner of the electric clutch described in
the Specification of P. W. Willans No. 16347 of 1890.
Usually there need be only two pairs of gear wheels & pinions, but whether two
or more and a suitable form or number of electro magnets, the arrangements and
combinations described form variable speed gearing by means of which a motor may
be kept running at one speed & impart to other apparatus by means of gearing of
fixed ratios, any speed between the fixed limits, or the motor may be started driving
at one speed or running free & may without shock impart the necessary speed to
the driven apparatus & the change of speed may be quickly or slowly made while
running.
By this means the engine or motor in a station for generating the current
employed for working tramways or railways or for working machinery requiring
great power for starting and comparatively small rower when running, may be

page_text: of much smaller power than has hitherto been possible because by the use of the
apparatus the maximum load upon the engine will be reduced & the load curve will
be straightened.
The apparatus described may be employed in connection with that shown &
described in the Specification of the Patent granted to me No. 6493 of 1886.
31 March 189)
W. WORBY BEAUMONT.
COMPLETE SPECIFICATION.
Electro-magnetic Variable Speed Gearing.
I, WILLIAM WORBY BEAUMONT 100 Palace Road Tulse Hill, S.W., Civil
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:-
My invention relates to the construction of apparatus and gearing for imparting
variable velocity or variable speed of rotation to machinery or to vehicles while the
gearing itself or part of it receives a nominally uniform speed of rotation.
On the spindle of a motor or shaft driven by a motor of any of the well known
kinds, or by any source of rotatory motion, I fix an electro magnet or magnets of the
disc, iron clad, or the multipolar types, the exciting coils or wires of which are
supplied with current from collectors, commutators, brushes, or apparatus for
distribution on the said spindles or otherwise conveniently placed and receiving
current from a source, by wires or conductors which are arranged in connection
with switches & shunts either in pairs or by three wire systems of arrangement or
combinations of these.
The faces or peripheries of these said magnets, which, in the case of disc or
similar form are plain, or are radially or concentrically corrugated or toothed with
a view to obtaining strong frictional grip with small magnetic strength of pull may
be covered or faced with or separated by a non-magnetic medium to avoid effects of
magnetic persistence. The said faces are adjacent to similar or corresponding faces
formed on discs attached to or forming part of the wheels or pinions which being on
the same spindle or adjoining spindle or shaft are to be driven or carried round by
the magnet.
These wheels or pinions are of different diameters & gear with the
wheels or pinions of the machinery, apparatus or spindles to be driven at different
speeds. These wheels or pinions may be wholly or partly of non-magnetic materials
such as gun metal or phosphor bronze. The current used for exciting the magnets
may for instance when the apparatus is used for driving tramway cars or for similar
purposes by electro motors be passed through wires which form part of the motor
circuit or may be ou separate circuit. The wires may be so coupled up to the
apparatus and to switches and resistances where required, that the strength of the
field of the magnet, or either of the magnets, may be varied so that the change from
the speed belonging or proper to one wheel and pinion, to that proper or belonging
to another of the gear wheels and pinions shall not be accompanied by shock, the
one gradually ceasing to have power to drive and the other of the set, gradually
receiving enough power to drive.
In some cases the connection between the magnets & the discs on or connected
with the pinions of the wheels to be driven may be by means of alternate discs or
plates after the manner of Weston's friction clutch.
When the magnet or magnets act circumferentially they will be encircled by or
will encircle without touching the parts they drive as in or after the manner of the
electric clutch described in the Specification of P. W. Willans No. 16347 of 1890.
For or in most applications there need be only two pairs of gear wheels and
pinións, but whether two or more and a suitable form or number of electro magnets
be employed the arrangements and combinations described form variable speed
gearing by means of which a motor may be kept running at one speed and impart

page_text: to other apparatus by means of gearing of fixed ratios, any speed between the fixed
limits with some small frictional loss, or without such loss any of the fixed speeds
corresponding with and proper to those fixed limits or the motor may be started
driving at one speed or running free and may without shock impart the necessary
speed to the driven apparatus and the change of speed may be quickly or slowly.
made while running.
By this means the engine or motor in a station for generating the current
employed for working tramways or railways, or for working machinery requiring
great power for starting and comparatively small power when running, may be of
much smaller power than has hitherto been possible because by the use of the
apparatus the maximum load upon the engine will be reduced and the load curve
will be straightened.
In the accompanying drawings which illustrate some of the forms which the
mechanism may take in accordance with my invention.
Fig. 1 is a longitudinal section and elevation, and
Fig. 2 an end elevation of a form in which two sizes of pinion or wheel, are
placed between two disc magnets.
Fig. 3 is a section & elevation of an arrangement according to which two
different sized pinions or wheels are placed outside two peripheral magnets.
Fig. 4 is an end view of this arrangement.
Fig. 5 is a section & elevation of an arrangement in which two different sizes
of pinions or wheels are placed outside one double magnet &
Fig. 6 is a section & elevation showing in part an arrangement according to
which the armature discs of the pinions or wheels are separated from the magnet
by intervening plates, alternately connected to the pinion & to the shaft or
spindle.
In all these illustrations the saine letters indicate in all the forms shown the
same or similar parts.
In Fig. 1, A is a shaft or spindle which receives rotary motion from a source
.of power & at a nominally uniform rate. A 2 is a shaft or spindle to which it is
desired to communicate rotary movement at different speeds.
.On the spindle A are fastened by suitable means the discs B grooved & carrying
a coil of insulated wire C, to which an electric current is supplied from the con-
ductors & I through brushes or contact pieces E bearing against the collector
rings D thus constituting the discs B electro magnets. In the drawing two
arrangements of collector rings and contact pieces are shown. On the same spindle
and between the electro magnets B B, are placed pinions or wheels J J gearing
into wheels K K on the shaft. A 2. The discs HH form the armatures to the
magnets B B, and they are separated from the faces F of the magnets by an
intervening disc G which may be of non-magnetic material, or may be of iron or
steel in cases where it is necessary to have a wearing part and where it is not
necessary to avoid the effects of remenant magnetism.
The discs G may be attached to the magnets B or discs H or may be simply.
slipped upon the shaft between these. The pinions J J are loose upon the
shaft A & are fitted with brushes N N suitable means for lubrication not shown
being required. The wheels K are fixed upon the shaft A 2.
When it is necessary
to, drive the shaft A 2 at the lower limit of speed permitted by the ratios
of the gearing adopted in any case electric current is sent into the coil C of the
magnet next the small pinion J. The armature H is then magnetically held to the
magnet disc and in proportion to the magnetic pull and the friction between H G
& F power will be conveyed through the larger wheel K to the shaft A 2,
Figs. 1 & 2.
Between the pinions J is a collar L, & at M is a collar for keeping the collector
ring D in place and their insulating material shown black when that form of
collector ring is employed.
In Figs. 3 & 4 the magnets B are provided with coils C in a groove or channel
which at its periphery has polar projections P, revolving within but not touching

page_text: the internally projecting polar pieces formed within the casing P, cast or connected
with the pinion J & in so far taking the place of the disc H in Fig. 1. The magnet
and polar portions here shown are similar to those described in the Specification of
P. W. Willans No. 16347 1890. In this arrangement the smaller or larger wheels
or pinions J J will transmit motion to the wheels K or K at their respective
speeds not by the frictional hold obtained by the means described with reference
to Figs. 1 & 2 but simply by what may be called magnetic drag.
In Fig. 5 the pinions or wheels J J are placed outside a double maguet B
provided with two coils. C, C, supplied with current by means of contact
pieces E, E, E bearing against collector rings D, D, D, the central ring acting
as also shown in Fig. 3, as conductor alternately to or from either of the coils.
The action of this arrangement of variable speed gear is similar to that described
with reference to Fig. 1. But the wheels or pinions J J are shown with teeth for
chain gearing though they may, like the other examples shown, be provided with
toothed gearing or might be made as pulleys to carry belts or ropes.
The disc H of the smaller pinion in Fig. 5 is shown as corrugated or provided
with a number of V shaped annular grooves and the disc G which may be
attached to the face F of the electro magnet is correspondingly formed as shown
at F2 in Fig. 5. By the extension of the width of the magnet at the faces,
annular grooves might also be made in its face and the ridges of the disc H might
fit thereinto or a double faced ridge and groove piece instead of the singly faced
grooved & ridge faced disc shown in Fig. 5, might be employed with the same
object namely to produce a powerful frictional grip or hold between the magnet B
and the disc H with a comparatively small magnetic flux or small consumption of
electricity. This arrangement of annular grooves and ridges or equivalent coned
surfaces may be employed with the other forms of the variable speed gear as in
Fig. 1 and it may be employed on both sides of the arrangement shown in Fig. 5.
In all the arrangements shown the magnet or magnets B are fixed to the shaft
or spindle A by suitable well known means such as keys, set screws, by making
that part of the shaft square or by screwing the shaft at that part and the interior
of the boss of the magnet.
The arrangements necessary with regard to the coil C and the connection between
them and the collector rings & bushes or contact pieces and the eléctric
circuit wires are such as are commonly known to electrical engineers. The pro-
portions & sizes of wires in the coils & other parts and in the form & quantity of
metal in the magnets & armatures are such as must be determined in accordance
with the requirements of each application in accordance with now well known
electro magnetic & electro mechanical knowledge & practice.
In Fig. 6 is shown a modification of my invention according to which the face of
the magnet B and that of the armature disc H is separated by intervening plates R
which are alternately connected to the disc H by projecting portions, the screw
studs T & the bosses Q & to the shaft A which at the part shown may be square
in section. Thus some of the alternate plates are fixed to the shaft while the
others are carried by the pinion J & disc H. Upon the current being sent into the
coil C the magnetic circuit is partly made up or provided by the plates R and
disc H and the frictional hold is increased in proportion to the number of the
surfaces of the plates although magnetic resistance caused by the joints between the
plates somewhat diminishes the magnetic efficiency. The object of the arrangement
is to increase the number of the surfaces up to the number which will permit
decrease in the electricity necessary for energising the magnet. In some cases the
plates R may have between them a thin non-magnetic plate or may be electro
plated for the purpose already described.
In each of the drawings I have shown the driving pinion wheel or pulley as part
of or attached to the armature. It is obvious that as an equivalent or modifi-
cation the armatures except in the case of Fig. 5 might be fixed & the magnet
free on the shaft & fitted with wheel or pinion but this arrangement is not so
good as that shown.

page_text: 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 I do
not claim the use of those electromagnets which with their armatures are known
as magnetic clutches, couplings or brakes and acting as such but what I do
claim is
First The method of and apparatus for imparting a variable speed of rotation
to a driven spindle or mechanism which consists in the combination of wheels or
pinions of different sizes with a double or two or more electromagnets and their
armatures on a driving shaft or spindle in such a way that either or any of the
said wheels or pinions may selectively at will be made driving wheel or pinion
according to the speed for the time being required substantially as herein described
and shown.
Second; The combination of two or more electro magnetic clutches or couplings
with gear wheels or pulleys so arranged that they constitute variable speed
driving gear substantially as and for the purpose herein described and shown.
Third; In electro magnetic variable speed gearing the double magnet and the
annular grooved disc armature and plates substantially as described and shown with
reference to Fig. 5.
Fourth; In electro magnetic variable speed gearing the arrangement of three
wires and collectors to two magnet coils substantially as shown and described with
reference to Figs. 3. 5. & 6.
Fifth In electro magnetic speed gearing the employment between the magnet
face & the armature of the friction plates & connections as shown & described
with reference to Fig. 6.
Sixth; In electro magnetic speed gearing the combination of armature and
driving pinion wheel or pulley in one or more parts substantially as herein described
and shown.
Dated the 31st December 1892.
W. WORBY BEAUMONT.