Improvements in Trolleys used on Overhead Wires for Electric Traction.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Trolleys used on Overhead Wires for Electric
Traction.
I WILLIAM WOOD, of the Power Station, St. George, Bristol, Engineer, do
hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in trolley heads used on wires for electric
traction, and has for its object to provide means for removing the danger to
which trolley heads as at present constructed are liable, and at the same time to
afford a more efficient means for fastening and adjusting the wearing parts and
for insulating and securing the head to the pole.
With trolley heads now in use, there is a constant liability to accidents on
account of the lower part of the head which carries the fork projecting below that
part by which it is attached to the pole, and forming an angle therewith, and when
the trolley wheel leaves the wire, the trolley is dragged along, and the insulators,
wires, and their supports frequently get entangled with the head, thereby doing
serious mischief and endangering the lives of passengers, whilst by the imperfect
means used for covering that part of the pole which receives the head, insulation
is often defective, the method adopted for attaching and adjusting the fork
to the head, being also unreliable, is another source of danger and delay.
The shape of the present trolley heads allows their bases to be exposed and liable
to catch in the wires, supports, and insulators, causing one or other of them to
be broken; to remedy this, a shield is formed on the head, extending from the
bottom where the spindle of the fork rests to the part by which it is attached
to the pole, this completely protects the parts at present exposed, and serves as
a guide, so that in case of a trolley leaving its wire, it will pass harmlessly over
any wires or insulators. The tubular portion of the head by which it is attached
to the pole is at present insulated by packing it with asbestos or other non con-
ducting material, this process being a somewhat difficult one, it is very often
inefficiently performed, and the packing soon becomes loose, and the consequent
leakage is a prolific source of annoyance and danger, I therefore provide a hat
of mica or other suitable material to completely cover that part of the pole on
which the head is attached, and by this means insulation is made perfect. At
present the fork spindle is attached to the head by inserting it in the socket,
resting the shoulder on ball bearings, and adjusting the wearing parts by washers
and cottar pins; unless the bearing parts are frequently re-adjusted, they have
too much play, and the wheel jumps the wire in consequence; to remedy this
and to provide a ready means of adjustment, I form a screw-thread near the end
of the spindle, and continue it with a slightly diminished diameter beyond the
threads, in this part a slot is cut, an ordinary hexagonal nut is made with an
annular projection on its head, across which, an even number of cuts are made,
so that in whatever position, (within certain limits) the nut may be on the bolt
head of the spindle, one cut will be opposite another, and when the nut is in place,

page_text: a cottar pin is inserted from one cut to another through the slot in the spindle,
which will form a lock-nut, and allow the tension on the ball bearings to be
adjusted with nicety.
Dated this 6th day of Dation 1907
J. G. WESTLAKE,
Applicant's Agent, 2, John Street, Bristol.
Improvements in Trolleys used on Overhead Wires for Electric
Traction.
I, WILLIAM WOOD, of the Power Station, St. George, Bristol, 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 relates to improvements in trolley heads used on overhead wires
for electric traction, and has for its object to provide means for removing the
dangers to which trolley heads as at present constructed are liable, and at the
same time to afford a more efficient means of fastening and adjusting the wearing
parts and also of insulating and attaching the head to the pole.
The means employed for carrying my invention into effect will be fully
described in connection with the accompanying sheet of drawings, in which
Fig. 1 is an elevation and part section, Fig. 2 a plan, and Fig. 3 an end view of
a trolley head as fitted on the end of the pole ready for action on overhead wires.
The same letters indicate the same parts in all the figures.
A is a plate of metal with a double flange or rib at its lower edge a, which is
attached to the socket B which carries the fork spindle E and is continued to
the boss or tubular portion of the head C, which surrounds the pole D, the rib
or flange a is set to project slightly below the end of the spindle E so as to
protect the spindle from injury, and at the same time to form a guide to enable
the trolley to pass over the wires or insulators without doing any serious injury
in case the wheel should accidentally leave the wire.
Instead of filling the space between the boss C and the pole D with loose
asbestos, mica, or other non conducting material, I use a cylindrical hat F open
at one end and partly closed at the other, made of mica or other suitable material,
the open end of the hat enables it to be placed around the pole and the partially
closed end permits the screw-threaded end of the conducting wire which con-
veys the current from the overhead wire to the motors to pass through, a nut J
placed on the end of the conducting wire tightens and fixes the boss and hat on
the pole, while the nut K tightens the boss at the lower end of the plate A thus
forming complete insulation." After repeated experiments it is found that rubber
is the most suitable material for the hat, as it is more readily compressed into
its required position than mica or other non resilient materials.
The fork spindle E is fitted to rest in the socket B on the usual ball bearings,
but the end of the spindle is very finely screw-threaded at G, and a corresponding
nut H similarly threaded is placed thereon; on the lower face of the nut a
number of apertures h are cut, each having a corresponding aperture on the
opposite side, a hole g is made near the lower end of the spindle to receive a
cottar pin by this means the nut may be very slightly turned, to give the most
delicate adjustment, then by the insertion of the pin through one aperture, the hole

page_text: in the spindle, and the opposite aperture, the nut is locked and the spindle and
fork secured to their bearings in the socket; when it is required to re-adjust the
bearings, the pin is removed and the nut tightened as required, the pin again
secures the spindle and fork in position.
The fork and trolley wheel as shown in the drawings are already in use, and
therefore require no description; the upper part of the boss or tubular casing is
fitted with any hard insulating material I to protect it from electrical contact
with the with the wires when the trolley is being shifted from one wire to the
other.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In trolley heads for overhead electric traction, making the plates which carry
the trolley with a double flange at the base projecting beyond all the wearing
parts to protect them as they pass over the wires or insulators, substantially
as described.
2. In trolley heads for overhead electric traction securing the insulation of the
trolley pole by covering it with a hat of mica, rubber, or other non conducting
material, substantially as described.
3. In trolley heads for overhead electric traction, making the adjusting screws
for taking up the wear of the ball race with fine threads and chases cut in the
opposite sides of the nuts to receive each end of a cottar pin inserted in the
spindle, whereby a fine and reliable adjustment is obtained, substantially as
described and shown.
Dated this 3rd day of September 1898.