Improvements in Trolleys or Sliding Contacts for Electric Cars.
Year: 1897

page_text: Date of Application, 27th July, 1897-Accepted, 20th Nov., 1897
COMPLETE SPECIFICATION.
Improvements in Trolleys or Sliding Contacts for Electric Cars.
A communication from abroad by ALVARO SILAS KROTZ, Electrician, WILLIAM
PRESTON ALLEN, Travelling Salesman, and OLIVER SMITH KELLY, Manu-
facturer, Citizens of the United States, residing at Springfield, in the County
of Clark, and State of Ohio, U.S.A.
I, WILLIAM LLOYD WISE of 46 Lincoln's Inn Fields, in the County of London,
Consulting Engineer & Chartered Patent Agent 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:-
This invention relates to improvements in trolleys or sliding contacts for electric
cars, as applied to railways.
The particular object of the invention is to provide a trolley of few parts adapted
to maintain an even and uniform sliding contact with the stationary contact rail
or working conductor. A further object is to provide for a simple and easy
renewal and adjustment of parts. I accomplish these results, by supporting the
contact shoe on one or more thin strips of resilient metal, of a proper curvature
to maintain a parallel movement of the contact-shoe against the contact-rail.
In the accompanying drawings, Figure 1 is a side view of an efficient form of
trolley embodying the invention, and Figure 2 is an edge view of Figure 1.
Figure 3 is an end view of a modification of trolley especially designed for
heavy service and direct pressure contact, and Figure 4 is a side view of Figure 3.
Figures 5 and 6 represent modifications of the trolley shown in Figures 1 and 2.
In all the figures C designates the contact-rail or working conductor, and A¹
the sliding contact carried by the trolley. A designates the spring supports for
the contact shoe A¹. A³ is a shorter stiff or rigid strip or stop adapted to limit
the lateral movement of the spring and contact shoe, when the latter is not in
contact with the contact-rail. The spring support A and stop A³ are clamped at
their upper ends to a support A4, or to insulating pieces B, by means of bolts B¹
as shown. The support or pieces B B' may be insulated from and attached to the
truck or car frame in the usual manner.
To increase the conductivity of the trolley between the contact shoe and the
upper or supported end of the spring support A.; where connection is made as
usual to the motor conductor, not shown, a soft copper strip A5 of high conduc-
tivity is placed in position beside the spring A, or a flexible cable A50 may be
attached direct to the shoe A', as shown in Figure 3, said cable being connected
to the motor-conductor on the car, so as not to interfere with the proper motions
of the trolley. Or if desired the springs A may be backed or faced with a suitable
metallic conductor applied in any desired manner.
In Figures 3 and 4 the spring supports are wholly interposed directly between
the support B and shoe A, and two semi-elliptic springs A10 are employed bolted
together at their ends as at A° and at centers respectively to the support B and

page_text: shoe A. The tendency of these springs is to force the shoe and support apart,
and thus keep the shoe in close contact with the contact-rail, and a shackle
stop AA is employed to limit the separation of the support and shoe when the
latter is clear of the contact rail. This construction is substantially a duplication
of the other construction and is especially useful with heavy loads, large currents
and where the cars are to run in both directions on a single track. In these
figures (3 and 4) the metallic trolley conductor A is also formed of oval form.
Figure 6 represents the spring A and shoe adapted for an upward-pressure con-
tact. Figure 5 represents the same adapted for an angle contact.
The spring supports are all preferably wide and thin and when curved, as shown,
the shoe remains in perfect contact regardless of the swing of the car or uneven-
ness of the contact rail.. I prefer to use two springs A on each trolley, as shown
in Figure 1. However, I do not confine myself to any number; neither do I
confine myself to any particular curvature, although the one shown in Figure 2
is preferable for ordinary uses.
It is obvious that the springs can be curved to adapt the trolley to any position
of the contact rail without departing from the scope of the invention.
The supports A or pieces 1, or their equivalent, constitute a base to which the
trolley springs are attached.
As will be observed by reference more particularly to Figures 2, 5 and 6, a
conductor strip of high conductivity connects the contact shoe with the metal
support or base A+ in Figure 2, or the pieces B in Figures 5 and 6, and the spring
support A in said figures is curved to substantially a U-shape with the arm to
which the contact shoe is fastened shorter than the arm which is attached to the
base or support A4, or B; the contact shoe being maintained on the shorter arm
of the spring so that said shoe will stand in a plane between the base or support A*,
or B, and the curved portion of said spring support, so as to maintain an even
contact with the stationary conductor C, and compensate for vertical or lateral
movement.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. In a trolley, the combination of the base, one or more springs rigidly attached
at one end to said base, a contact shoe on the free end or portion of said spring or
springs, said spring consisting of a curved flat sheet of resilient metal; and a rigid
stop adapted to limit the play of said spring or springs, substantially as described.
2. In a trolley, the combination with a base, one or more curved springs rigidly
attached at one end to said base, a contact shoe supported on the free end or ends
of said spring or springs, said spring or springs being backed or faced with a strip
of soft copper or other good conducting material.
3. In a trolley, the combination with a base, one or more springs, a contact shoe
attached to the free end of said springs and a conductor of high conductivity con-
nected with the contact-shoe and to the base, and a stop for limiting the play of
the spring, substantially as and for the purpose specified.
4. In a trolley, the combination of a base, a flat curved spring and a contact
shoe attached to and supported by said spring, and a conductor strip of high
conductivity connecting the contact shoe with the base or metal support, said
spring support being curved to substantially a U-shape with one arm shorter than
the other; with the shoe mounted on the shorter arm of the spring, so that said
shoe will stand in a plane between the base and the curved portion of said spring
support so as to maintain an even contact with the stationary conductor and com-
pensate for vertical or lateral movement, substantially as specified.
5. The improvement in trolleys or sliding contact supports for electric railways
substantially as shown and described with reference to Figures 1, 2, 5 and 6 of
the drawings.
5

page_text: 6. As an improvement or modification of the trolley set forth in Claim 5 the
construction shown and described with reference to Figures 3 and 4 of the
drawings.
Dated this 27th day of July 1897.
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.