Improvements in Current Collecting Apparatus for Electric Tramways.
Year: 1897

page_text: Date of Application, 15th Apr., 1897
Complete Specification Left, 17th Jan., 1898-Accepted, 19th Feb., 1898
PROVISIONAL SPECIFICATION.
Improvements in Current Collecting Apparatus for Electric
Tramways.
CHARLES WILLIAM GODSON LITTLE, Heckington, Lincolnshire, Engineer, ARTHUR
JAMES IRELAND, 20, Lawn Crescent, Kew Gardens, Engineer, doo hereby declare the
nature of this invention to be as follows:-
Our invention relates to an improved means of supporting & actuating the trolley
arm used on electric tramways for collecting current from the overhead conductor
whereby the springs used for actuating the trolley arm and by means of which the
collector is kept in contact with the overhead conductor are arranged to be placed
inside the supporting standard thus obviating the objections due to outside springs. By
our improved means of supporting the trolley pole we also secure an almost constant
force of contact between the collector and the overhead conductor. Our invention
consists in the combination with a plunger located inside the trolley standard of two
or more helical springs these springs being of such diameters that they will fit one
within the other. The cross section of the wire of which these springs are made is so
chosen for each that altho' the several springs are of different diameters they
nevertheless would each give approximately the same deflection for the same load.
The upper part of the plunger acts upon a lever in connexion with the trolley pole
thro' a piece projecting from the lever.
The angle between the axis of the trolley pole and a line passing thro' the point
of contact of the plunger with the projecting piece and thro' the fulcrum of the lever
is so chosen with respect to the springs employed that the upward force of the trolley
pole is most nearly constant thro' the working range of the trolley arm.
The helical springs above referred to we find most conveniently made by being
double wound in a manner somewhat similar to that frequently employed in the
construction of steam indicator springs.
With a light trolley arm one spring double wound as above described is
sufficient.
The upper part of the combination of springs is attached to a sleeve carrying the
lever trolley pole, which sleeve is free to turn round the trolley standard and if
necessary on ball bearings.
"
Improvements in Current Collecting Apparatus for Electric
Tramways.
We, CHARLES WILLIAM GODSON LITTLE, of Heckington, in the County of Lincoln,
Engineer, and ARTHUR JAMES IRELAND, of Glencoe, 10, Mortlake Road, Kew, late of
20, Lawn Cresent, Kew Gardens, in the County of Surrey, Engineer, do hereby
[Price 8d.]

page_text: 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: —
Our invention relates to an improved means of supporting and actuating the
trolley arm, or pole used on electric tramway vehicles for collecting current from the
overhead conductor, whereby the springs used for actuating the trolley arm, or pole
and by means of which the collector is kept in contact with the overhead conductors,
are placed inside the supporting standard thus obviating the objections incidental to
outside springs. By our improved means of supporting the trolley arm or pole we
also secure an almost constant force of contact between the collector and the overhead
conductor. According to our invention we use, in combination with a plunger
situated inside the trolley standard, two, or more, helical springs of such diameters
that they will fit one within the other. The cross section of the wires of which
these springs are made is preferably so chosen for each spring that, although the
several springs are of different diameters, they nevertheless will each give
approximately the same deflection for the same load. The upper part of the plunger
acts upon a lever in connection with the trolley arın, or pole, through a piece
projecting from the said lever.
The angle between the axis of the trolley arm, or pole, and a line passing through
the point of contact of the plunger with the projecting piece and through the
fulcrum of the lever, is so chosen, with respect to the springs employed, that the
upward force of the trolley arm, or pole, is most nearly constant through the working
range of the trolley arm, or pole. For example an angle of 35° is a suitable
angle with a standard trolley pole, or arm, and attachments, of about 50 lbs. weight,
and with springs which will give an upward pressure of 30 lbs. upon the overhead
conductor. In order to obtain sufficient strength and at the same time to keep the
dimensions of the springs such that they are suitable to be placed inside an ordinary
trolley standard we prefer that the springs be double wound in a manner somewhat
similar to that frequently employed in the construction of steam engine indicator
springs.
With a light trolley arm, or pole, one spring, double wound as above described, is
sufficient, but if the arm, or pole, be as heavy as the usual standard one, we use
two, or more, such springs. The upper part of the springs is attached to a sleeve
carrying a bracket for the fulcrum of the lever of the troiley arm, or pole, which
sleeve is free to turn round the trolley standard and it may run
bearings.
on ball
The accompanying drawing represents in vertical section in Figure 1 and side
elevation in Figure 2 an arrangement of apparatus according to our invention.
The trolley standard A contains the plunger or sliding tube B which passes through
a hole in the top of the sleeve piece C secured to the upper part of the trolley
standard and capable of turning thereon, ball bearings at c c² facilitating its
movement. The upper end of the plunger or tube B has a head 6 provided in its
centre with a hole b¹ through which the conductor G for current froin the overhead
wire passes and on the lower end of the tube is secured an annular disc or flange a
which fits easily within the standard A and constitutes a guide for the plunger in its 4
longitudinal movements in the said standard. The sleeve-piece C carries the bracket c³
for the fulcrum C2 of the lever d in which the trolley arm, or pole, D is secured.
This lever has projecting pieces or brackets d² carrying rollers d' which bear on the
head b of the tube or plunger B. Inside the trolley standard and surrounding the
tube or plunger B are springs E and F the upper ends of which pass through openings
in the top of the sleeve piece C and are secured thereto by nuts e the lower ends of
the said springs being similarly connected to the annular flange a on the lower end
of the tube or plunger B. These springs as shewn clearly in Figures 3 and 4 are
coiled so that each is a double spring the convolutions of each portion (1) of each
double spring being situated between the coils of the other portion (2) of the same
double spring. The lower parts of the springs instead of being connected to the disc

page_text: or flange a as described the parts which join the two portions of each of the double
springs may be continuous and be connected with the tube or plunger B by being
passed into slots 62 cut up into the lower end of the said tube or plunger B, as
shewn in Figures 5 and 6. The tension of the springs may be adjusted by making
the upper portion B2 of the plunger or tube B to screw onto the said part B as shewn
at K, Figure 1. To prevent the sleeve piece C making more than a single rotation
there is provided on the standard A at the part enclosed by the sleeve piece Ca
projection with which a projection 2 on the sleeve piece comes into contact.
When it is required to allow the sleeve piece C with the trolley arm D to make
more than a complete revolution or several revolutions on the trolley standard A the
projection on the sleeve piece C is removed or dispensed with and the plunger or
sliding tube B is made in two parts B B¹ as shewn in Figure 5 the said two parts
being connected together by an insulating piece g. The lower part B¹ of the plunger
slides in a metallic bush a² in an insulating support a¹ connected to the trolley
standard. A convenient way of attaching the cable conductor G by which the
current is led from the overhead conductor to the motor is to lead it through the
hollow trolley arm or pole between the projections d² carrying the rollers d³ through
the central hole b¹ in the head b, down through the plunger or tube B through a
hole in the insulating piece g which connects the lengths B B' of the plunger or tube
together, and soldering, or otherwise electrically connecting, it to the lower part B',
of the said plunger or tube, which slides in the metallic bush piece a² in the
insulating support a connected to the trolley standard, the continuation of the
conductor being soldered or otherwise electrically connected to the bush a² and
continuing thence to the motor. The trolley standard A may have a door in it as
shewn at H Figures 5 and 6 to give access to the points of connections of the
conducting wire. The disc a Figures 3 and 4 may be used in the arrangement
illustrated in Figure 5 the springs E and F being connected to the said disc as in
Figure 3 instead of being inserted in slots in the plunger.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed we declare that
what we claim is :-
1. In current collecting apparatus for electric tramways having a trolley standard
carrying a trolley arm or pole, a doubly wound helical spring or two or more doubly
wound helical springs, one inside the other, the said spring or springs being situated
inside the trolley standard and acting in opposition to the trolley arm or pole
substantially as herein before described.
2. In current collecting apparatus for electric tramways a trolley standard provided
with an arrangement of doubly wound helical spring or helical springs in its interior
acting upon a plunger or tube which acts upon a projection from the trolley arm or
pole or from the lever in which the trolley arm or pole is carried substantially as
hereinbefore described.
3. The arrangement and combination of parts constituting part of the collecting
apparatus for electric tramways substantially as herein before described and illustrated
in the accompanying drawings.
Dated this 15th day of la 1000
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.