Improvements in the construction of Electro-motors for the propulsion of Tram Cars, Electric Locomotives, Vehicles and other purposes
Year: 1886

page_text: PROD.
I ALFRED JAMES JARMAN of No 443 Brixton Road S.W, in the county of
Surrey Electrician and Electrical 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 consists in Improvements in the construction of Electro-motors for
the propulsion of Tram Cars, Electric Locomotives, Vehicles and other purposes.
The object of the invention is to permit a suitably constructed electro-motor or
motors of any type size or kind in which the critical speed of the motor or motors
is higher than the vehicle or machinery to be driven to transmit power with as
little friction as possible and to enable a reverse motion of such motor, vehicle or
machinery without the employment of any of the usual reversing gear such as bevil
wheels, mitre gear, large or small crown racks clutches and. the like, and without
the well known double brush system as applied to one collector or commutator of a
single armature.
In carrying out my invention I fix two armatures upon one axle or spindle and
employ two sets of field magnets fitted to one common base plate and the tops of
the field magnets fitted to one common yoke thus forming a compound electro-
motor. A toothed or other suitable wheel is fitted upon any convenient part of
the axle or spindle for communicating power to other wheels or machinery required
to be set in motion. Each armature has a collector or commutator of its own, and
a pair of conducting wire brushes or plates.
These brushes or plates are so arranged that one armature can revolve in one
direction when a current of electricity is allowed to circulate through it and its
field magnets and the brushes of the other armature are so arranged that it may
revolve in the opposite direction when a current of electricity is allowed to circulate
through it and its field magnets. The reverse motions are obtained by the brushes
or plates being lifted off the collector or commutator of one armature by any
suitable mechanical contrivance while the brushes or plates of the other armature
are placed upon its commutator or collector by the same mechanical contrivance,
Price 77

page_text: In the
It will be seen that by this means one armature becomes a fly wheel to the other
armature that is in active operation and thus gives a very steady motion. Another
advantage of my invention is that as one armature is liable to become heated by
long continued action and the great strain that is put upon it at irregular intervals
during the period of travelling that by setting the other armature in motion in the
reverse direction as in the return journey of a tram car, the armature that was
previously in action becomes rapidly cooled by its being revolved. By this means
each armature is made capable of giving its full efficiency, and the dangerous effects
of overheating so common in ordinary electro motors is entirely overcome.
wheels that transmit the power from the electro-motor if toothed wheels are
employed the teeth may be either fixed or they may be made to revolve, If the
latter means is employed the friction is very considerably reduced, the teeth may
be made of any suitable shape to answer the purpose, or wheels having a grip by
friction may be employed or steel wire belting running over leather faced pulleys.
The electricity for the driving of the above described electromotor may be
supplied to it through the rails of a tram line or railway or otherwise; direct from
any generator of electricity or by the employment of secondry storage batteries or
primary batteries or the combination of primary and secondry batteries.
In order that my invention may be clearly understood reference may be made to
Fig. 1. A and A 1 shew the field magnets with their armatures, collectors or com-
mutators and brushes or plates and the small toothed wheel B situated between the
two armatures for the transmission of power from the motor. C is the iron base
plate of this compound electro motor, and D the iron yoke that joins the top bars
of the field magnets. It will be seen that the wire brushes or plates are so
arranged upon the collector or commutator that the armature within the field
magnets A is capable of running in the opposite direction to the armature within
the field magnets of A 1. This is accomplished by any suitable mechanical con-
trivance that will take one pair of wire brushes or plates off the collector or
commutator of one armature, at the same time placing the wire brushes or plates
upon the collector or commutator of the other armature. E and E1 are two metal
discs into which the teeth of the wheel B accurately fit, thus giving additional
strength to the teeth, while they; when revolving act as a flywheel in conjunction
with one of the armatures, thus producing a very steady motion. The motor may
be divided and thus fitted or fixed seperately for accomplishing the before
mentioned motions, but if fitted thus they are not nearly so well suited to the
purpose as a compound motor as described. In the compound motor, the armature
that has been last working becomes thouroughly cooled by its being revolved in the
air by the action of the opposite armature. The compound motor above described
is self contained in a very solid and substantial manner, it being easily fitted or
fixed in any suitable place where it is required to perform its work.
Fig. 2 shews a suitable arrangement for transmitting the power from the electro
motor above described to the axle or axles of the vehicle or machinery to be
driven.
The small toothed wheel F represents the toothed wheel B of the motor in Fig. 1.
F communicates motion to G and G communicates motion to H and H communi-
cates its motion to I and J represents the axle to be driven by the wheel I. The
wheel I is represented as having revolving teeth made of pieces of round bar steel
or other suitable metal or alloy, and fitted into holes in the side rims of the wheel
truly bored to receive them. By adopting this form of tooth, friction becomes
greatly reduced. Fig. 3 shews the application of the Electro motor applied for the
propulsion of Tram Cars fitted with electrical storage or secondry batteries, at K
a portion of these storage batteries are shewn. The above described motor forms
for the propulsion of tram cars a very compact arrangement.
The dotted lines of the communicating wheels shew how the power is trans-
mitted from the electro-motor to the axle of the tram car while the other wheels are
left to be arranged for steering or not just as may be found necessary.

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 would have it
understood that I lay no claim to any special shape or size or position as these
may be varied in a number of ways without affecting my invention. I declare
that what I claim is
1. The fitting of two armatures upon one axle or spindle with its field magnets
so arranged as to form a compound electro motor, one armature being so arranged
that it will give motion in one direction and the other armature so arranged as to
give motion in the opposite direction the axle of such electromotor having a
suitable means attached to it for the transmission or communication of motion and
power.
2. Any suitable mechanical contrivance applied to such an electromotor for
lifting or removing the wire brushes or plates from the collector or commutator
of one armature, and placing the wire brushes or plates upon the collector or
commutator of the other armature.