Trollies for Electric Cars.
Year: 1891

page_text: Date of Application, 3rd Nov., 1891-Accepted, 5th Dec., 1891
COMPLETE SPECIFICATION.
Trollies for Electric Cars.
I, ROBERT DUNLAP NUTTALL, of Corner of Grant Avenue and Bownet
Street, Allegheny, Pennsylvania, United States of America, Manufacturer, 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 has relation to trolleys, for electric railway cars, and has for its
object, the provision of a novel device, for maintaining contact between a trolley
wheel, and an electric conductor with equal certainty on straight and curved sections
of the line, and notwithstanding any variations in the height of the conductor
above the roadbed, or irregularities in or on the conductor or joints or connections
of the same.
In order to fulfill the requirements above indicated, it is necessary that the
trolley wheel, should be supported upon the end of a rod, capable of motion, both
up and down, and in a circle, but always having a tendency to assume a vertical
position, under the resilient action of a properly arranged spring or springs, and
this has heretofore been accomplished in a somewhat unsatisfactory manner by
pivoting the trolley rod upon a swiveled frame and attaching springs to the rod
near its pivotal point, which, being stretched by any strain upon the rod that would
throw the same out of perpendicular, would tend to bear the rod against the strain
and return it to the perpendicular position when such strain was released.
Many of such structures have been found objectionable, owing to the fact that
the constant stretching of the springs has a tendency to weaken them, causing
them to break unexpectedly, and besides, such structures, or most of them, are
complex, cumbersome and expensive.
In carrying out my invention, I provide a suitable base adapted to be fastened
on top of a car, a swivel head mounted on such base, a yoke secured to such head
by a horizontal pivot, and formed with a socket, for the reception of the trolley rod,
a horizontal rod projecting out from each side of the swivel head and carrying spiral
springs and sliding cross heads, the latter being connected to the pivoted yoke by
suitable flexible connections, and the whole constituting a comparatively simple and
inexpensive trolley fixture, in which the expansive force, exclusively of coiled
springs, is utilized to give the desired resiliency to the trolley rod.
My invention consists in the novel construction, combinations and arrangements
of parts, and is fully shown in the accompanying drawings herein.
Figure 1 is a perspective view, Figure 2 is a vertical sectional view, and Figure 3
a side elevation, of my improvements.
A designates the base of the structure having feet aa aa through which pass
bolts securing the base to the roof of a car when the device is in use. The base A,
is formed with a central hole which receives the shank of a swivel head B, the
shank fitting the hole loosely enough to allow the head to turn easily. A yoke C,
is fitted to embrace loosely with its depending arms c, c, the swivel head B, and is
pivotally attached to said head by a horizontal bolt d, passing through the arms c, c,
and the upper part of the swivel head. A long rod E passes through the swivel
head B, below and at right angles to the pivoting bolt d, projects out an equal
distance on each side of the swivel head, and is fitted on each end with a
sliding cross head F, having bolts f, f, through their ends, the bolts being
framed with hooked ends that engage with the ends of chains y. The
chains g, g, extend to and are hooked into inclined slots h, h, in the links H, H,
which latter are pivotally attached to the lower ends of the depending arms c, c, of
the yoke C, by pivoting screws or belts i, i.
The yoke C, which consists of a single piece of metal, is cast with a socket K,

page_text: which receives the end of the trolley rod L, and the socket is formed with a saw
kerf M, on one side and with lugs m, mn, on each side of the kerf, through which
said lugs pass bolts n, n, that serve to draw the walls of the socket together, so as
to tightly embrace and firmly hold the trolley rod.
Between each of the cross heads F, and the swivel head B, and surrounding the
rod E, are strong spiral springs 0, 0, the resiliency of which is exerted to press
the cross heads out from the swivel head and strain the chains 9. 9. The springs
on each side of the swivel head being of equal strength, they will, when the
trolley is inactive, serve to maintain the trolley rod in a perpendicular position,
but when the end of the trolley rod is bent down, (as when the trolley wheel is
on the wire) the spring on one side will be compressed, as is clearly shown in
Figure 3 of the drawings, while the pressure on the other spring will be relaxed.
When the trolley rod is bent down in the opposite direction, the spring which has
been compressed will be released from pressure, and the pressure exerted upon the
spring on the other side of the swivel head.
The trolley rod being supported in a pivoted yoke which is carried on a swivel
head, it is obvious that the free end of the trolley rod is capable of universal
motion, within a very considerable range, and the springs which give the required
elasticity to the trolley rod being also supported and carried by the swiveled head,
exert their power with equal certainty, whatever the position of the trolley rod
may be.
As the springs act by expansion solely, being loose upon the rod E, and not
attached to the cross heads or the swivel head, there is little or no danger of the
springs being broken, however severe the usage of the trolley may be.
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
:-
First In a trolley for electric cars, the combination of a pivoted yoke, provided
with a socket for the trolley rod, a swivel head upon which said yoke is pivoted,
with a horizontal rod extending out from each side of the said swivel head, spiral
springs surrounding said horizontal rod, cross heads sliding on the same and
flexible connections attaching said cross heads to the yoke, substantially as
described.
Secondly-In a trolley for electric cars, the combination of a suitable base, a
swivel head mounted thereon, a yoke adapted to receive a trolley rod, and pivotally
secured to said head, with movable cross heads attached to said yoke by flexible
connections, and springs abutting against said cross heads, and so arranged that one
of them will be compressed when the trolley rod is moved out of the perpendicular,
substantially as described.
ThirdlyIn a trolley for electric cars, the combination of base A, head B,
swiveled thereon, yoke C, pivotally attached to said head, rod E extending hori-
zontally from each side of the swivel head, cross heads F, F, sliding on said
rod, and flexibly connected to said yoke, with the spiral springs O, O, interposed
between the cross heads and the swivel head, substantially as described.
Fourthly In a trolley for electric cars, the combination of a base, a swivel
head supported on said base, a trolley rod horizontally pivoted on said head, a
compression spring abutting against said head, and suitable connections between the
trolley rod and the outer end of said spring, all constructed and arranged
substantially as described, whereby the movement of the trolley rod will compress
the spring.
Dated this 2nd day of November 1891.
ROBERT DUNLAP NUTTALL.
By Henry Skerrett,
6, Livery Street, Birmingham, Agent for Applicant..