Improvements in Trolleys for Electric Railways.
Year: 1898

page_text: Date of Application, 2nd Aug., 1898-Accepted, 22nd Oct., 1898
COMPLETE SPECIFICATION.
Improvements in Trolleys for Electric Railways.
We, THE BRITISH THOMSON-HOUSTON COMPANY, LIMITED, of 83, Cannon Street,
in the City of London, Electrical Engineers, do hereby declare the nature of this
invention (which has been communicated to us from abroad by Frank E. Case,
residing at Schenectady, County of Schenectady, State of New York, United States
of America, Electrical Engineer), and in what manner the same is to be performed.
to be particularly described and ascertained in and by the following statement:
The present invention relates to trolleys employed on electric railways, and has
for its object to decrease the cost of manufacturing by lessening the number of
parts employed, and to provide a trolley which is adapted for a wide range of
movement in its operation, particular reference being made to its operation in
the lowest positions.
The present invention permits the omission of one of the lifting springs, a
sliding cross head and rods, and utilize instead a single spring or set of springs
to lift the trolley arm and act as a buffer when, for any reason, the contact wheel
leaves the overhead conductor and flies upward.
In the construction of trolleys, it is desirable to make the base or support as
low as possible, so that it will not interfere with the operation of the vehicle when
the trolley wire is in close proximity thereto. It has been found in trolleys as
ordinarily constructed that the principal fault is in locating the pivot, about
which the trolley arm moves, too high on the stand, so that when the outer or
free end of the arm is depressed the trolley pole, due to the curve therein, strikes
the suspended conductor, and either throws the trolley wheel out of contact with
the wire or causes excessive arcing by momentarily touching the wire from time
to time as the vehicle progresses.
In the accompanying drawing, attached to and made a part of this specification,
Fig. 1 is a plan view of my improved trolley stand, Fig. 2 is a side elevation of the
same with the trolley pole broken away; Fig. 3 is a section on the line 3-3 of
Fig. 2, and Fig. 4 is a diagrammatic view illustrating the advantage of the
improved trolley.
'
The base of the trolley consists of a circular casting A having the vertically
extending stud B (shown in dotted lines Fig. 2); this stud forms a swivel support
for the casting C, permitting it to turn freely thereon, both when it is desired to
reverse the trolley and run the vehicle in the opposite direction, and to allow the
contact wheel to follow the curves and irregularities in the conductor wire. To
establish electrical connection between the base and other apparatus on the vehicle,
a socket is provided having set screws for securing a conductor in place. In
lug on the casting C is mounted a pipe D which may be secured in any desired
manner. The outer end of the pipe is screw threaded and provided with nuts E
acting as a stop for the sliding head F.
Formed integrally with the sliding head F are outwardly extending lugs Fi
having tapered holes F in which are mounted the side rods G. Mounted upon
the inner end of pipe D) is a sliding collar I normally resting against lug C¹.
Extending laterally from the collar are lugs I¹ against which the curved portions J
017

page_text: of the fork abut. The pole socket L consists of a casting having an angular
receptacle for the trolley pole N, and a removable clamp M secured to the casting
by bolts. The lower portion of the socket is provided with a fork the sides of
which straddle the casting C. At the lower extremity of the fork are bosses
forming bearings for the socket, and extending transversely through the bosses
and the casting C is a shaft O which forms the center of movement of the trolley,
which is below the centre line of the lifting spring K. Formed integral with
the arms of the fork are lugs P, and rods & are hooked at their inner end to
lugs P, and held at the outer end, which passes through the cross head, by screw
threads and adjusting nuts. Surrounding the pipe D is a spiral spring K made
in two parts for convenience of manufacture, and under normal conditions is
employed for lifting the contact wheel at the extreme end of the trolley pole. In
addition to this the spring K is employed as a buffer to take up the shock when the
contact wheel leaves the overhead conductor and flies upward.
When the trolley is working under normal conditions the spring K is com.
pressed from the outer end by the cross head F; this gives the required upward
pressure to the trolley wheel on the end of the pole. With the parts in the
position shown, the curved lugs J on the fork engage with the lugs I on the
collar I, and prevent the pole from moving further to the left except for the
buffer action when the trolley leaves the wire. With the lugs J arranged as
shown, the trolley pole can move upward until it assumes a vertical position, a
further movement will compress spring K from the inner end. By utilizing the
spring K as a buffer as well as for lifting, we are able to dispense with the second
spring, pipe and cross head ordinarily employed, and situated diametrically
opposite from those shown; this decreases the cost of manufacture and maiu-
tenance, and also makes a trolley which is considerably lighter.
We do not, however, limit ourselves to a trolley so arranged that the spring K
acts only as a buffer when the trolley assumes a vertical position; if desired,
the spring may be so arranged that the trolley will have only a limited upward
movement, as 80°, for example.
In Fig. 4 is shown diagrammatically, the advantage of the improved trolley
over others with which we are familiar.
Q represents a trolley wire, and making contact therewith is a wheel R carried
by the other end of pole N. Ordinary trolley poles when pressed upward so
that their contact wheel engages with the overhead conductor, are more or less
curved, due to the pressure of the lifting springs; this is no particular objection,
so long as the trolley is working under normal conditions, but as soon as the
overhead conductor closely approaches the top of the car, the tension on the
lifting springs is increased, and the pole bends in a manner similar to that shown
in the drawing. The broken and dotted line indicates the ordinary construction
of trolley with the centre of motion of the pole placed comparatively high, and
above the centre of the lifting springs, it will be seen that the pole strikes the
conductor Q; this would prevent the operation of the trolley when the conductor
dropped to this point. By making the centre of motion of the trolley very low,
we are enabled to provide a trolley which will work between much wider limits
than heretofore.
Referring to Fig. 4, the centre of motion is about 6 inches lower than is cus-
tomary, and the curve on the pole is somewhat less, owing to the decrease in strain
on the lifting spring, and a safe working distance is provided between the wire
and the pole.
Having now particularly described and ascertaind the nature of our said inven-
tion (as communicated to us from abroad), and in what manner the same is to be
performed, we declare that what we claim is:-
1 In a trolley, the combination of a base, a combined lifting and buffer spring
extending in one direction only from the base, and a pole socket pivoted to the
base at a point below the centre line of the spring.

page_text: 2-In a trolley the combination of a base, a single pipe or equivalent frame
piece secured to the base and extending outwardly therefrom, a sliding cross head
mounted upon the pipe, a combined lifting and buffer spring, a pole socket
pivotally secured to the base at a point below the centre of the spring, and con-
necting links between the cross head and the pole socket.
3-In a trolley, the combination of a base, a pipe secured to the base, a sliding
cross head mounted on the outer end of the pipe, a sliding collar mounted
on the inner end of the pipe, B. combined lifting and buffer spring
located between the cross head and the collar, and adapted to be compressed from
each end, a pole socket pivotally secured to the base at a point below the centre
of the spring, and means on the socket for engaging with the sliding collar when
the pole rises to a predetermined height.
4 In a trolley, the combination of a base, a casting swivelled thereon, a pipe,
a cross head on the outer end of the pipe, a sliding collar provided with lugs also
mounted on the pipe, a combined lifting and buffer spring surrounding the pipe
and located between collar and head, a stop for limiting the outward movement
of the head, a forked pole socket pivoted to the base at a point below the centre of
the spring, and projections on the arms of a fork arranged to strike the lugs on
the collar when the trolley is at or near its vertical position.
5 In a trolley, the combination with a casting swivelled upon the base, a pipe
mounted in the lug on the casting and extending outward therefrom, a cross head
mounted unon the pipe at the outer end, a sliding collar having outwardly extend-
ing lugs mounted upon the pipe at the inner end, a combined lifting and buffer
spring between the collar and head, a stop limiting the outward movement of the
head, a pole socket pivoted to the casting at a point below the centre of the spring,
lugs on the head and pole socket in which are mounted connecting rods, and
devices on the pole socket engaging the lugs on the sliding collar when the is at
or near its vertical position.
6 In a trolley, the combination of a base, a vertically extending stud mounted
thereon, a casting supported by said stud, a single support extending outward
from the casting, a combined lifting and buffer spring mounted on the support,
a pole socket provided with a fork extension on its lower side the arms of which
straddle the casting, and a transverse shaft forming the centre of motion of the
trolley pole and socket situated below the centre line of the spring.
Doted this 30th day of July 1908
THE BRITISH THOMSON-HOUSTON COMPANY, LIMITED,
A. R. MONKS, Director.
ALFRED CLEMENTS, Assistant Secretary.