Improvements in Current Collectors for Electric Railway or Tramway Cars with Overhead Conductors.
Year: 1896

page_text: Date of Application, 28th Dec., 1896
Complete Specification Left, 27th Sept., 1897-Accepted, 30th Oct., 1897
PROVISIONAL SPECIFICATION.
Improvements in Current Collectors for Electric Railway or Tramway
Cars with Overhead Conductors.
We, SIEMENS BROTHERS & Co. LIMITED of 12 Queen Anne's Gate, Westminster
in the County of London, Electrical Engineers, do hereby declare the nature of
this invention (as communicated to us from abroad by Siemens and Halske of
Markgrafenstrasse, Berlin in the German Empire) to be as follows:-
This invention relates to pivotted supports for the current collectors of electrical
railway or tramway cars with overhead conductors of the kind described in the
Specification to our Patent No. 18196 of 1894, and it consists in improved mealis
for readily raising the said supports so as to effect a reliable contact of the trollies,
and for lowering them into a horizontal position when not in use.
For these purposes, the said supports or arms carrying the current collecting
bars or trollies are pivotally mounted on suitable more or less elastic carriers on
the roof of the car, and, when not in use, are turned down into a horizontal
position. For raising them into the upright position there are provided at a
certain distance on either side of the pivotal connection of the arm a cranked
pivotted lever, the bent up end of which bears against the underside of the arm,
and to which is connected a cord passing over guide, rollers to the end of the
car where it is provided with a pull, so that by pulling the cord the lever is turned
upward on its pivot and is thereby made to partially raise the arm into the upright
position.
To enable such raising to be effected from either end of the car, the two levers
are connected together by an endless wire loop stretched over guide rollers, so
that when the one lever is raised by the pull at one end of the car the other
lever will also be raised, and thus the contact arm will be lifted, on whichever
side of the car it may have been turned down.
When the arm has been partially raised as described, the bringing into contact
of the trolley or contact bar is insured by the following device.
On the pivot of the contact arm are mounted two discs which consequently
turn with the pivot, and which have each two parallel slots, one on each side
of the pivot, these slots being so arranged that when the contact bar is in the
vertical position they are almost horizontal, those of the one disc being inclined
at a slight angle from the horizontal in one direction while those of the other
disc are at a corresponding angle in the opposite direction.
With these slots are engaged rollers on the ends of two pairs of links extending
on either side of the contact arm and whose other ends have slotted connection
with pivot pins on horizontal bars connected by springs to the frame that carries
the contact arm. The connection of the links and their rollers are arranged
as follows: Assuming the contact bar and slotted discs to be in the above men-
tioned position the pair of links on the one side have their rollers engaged
respectively with the upper slot of the one disc, and the lower slot of the other -
disc, while the rollers of the other, pair are engaged respectively with the upper

page_text: slot of the last named disc and the lower slot of the first named one. The before
mentioned springs are arranged so as to exercise a pull on each pair of links
and rollers in opposite directions, 'away from the discs, so, that, the rollers will
be pulled against the ends of their respective slots, and will thus act with a
certain loverage in holding the contact arm in the upright position with spring
action, thereby pressing the contact bar or trolley effectually against the overhead
conductor while allowing the contact arm to be deflected to a greater or less
angle.
When the contact arm is turned downwards on its pivot, into the, horizontal
position, the two discs will turn from the above described nearly horizontal
position into one at right angles thereto, in which the respective slots are inclined
at a slight angle on each side of the vertical:
As the slots turn upward into this position, they will first exercise a pull upon
the uppermost rolleri and link on the one side and on the lowermost roller and
link on the other side, until an angle is reached. which corresponds to the slipping
angle of the rollers, whereupon the said rollers will slide down the slots nearer to
the axis of the contact arin, the effect of which will be that when the contact arm
has reached the degree of inclination corresponding to the above position of the
discs,, the action of the springs and their leverage will be so much reduced as
to allow the arm to drop into the horizontal position.
When, on the other hand, the contact arm is raised by the before mentioned
cranked levers to just beyond the above mentioned intermediate position, the
springs will cause it automatically to complete its motion to the upright position.
Dated this 28th day of December 1896
*...*
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION
Improvements in Current Collectors for Electric Railway or Tramway
Cars with Overhead Conductors..
We, SIEMENS BROTHERS, & Co. LD., of 12 Queen Anne's Gate, Westminster
in the County of London, Electrical Engineers, do hereby declare the nature of
this invention (as cominunicated to us from abroad by Siemens and Halske, of
94 Markgrafenstrasse, Berlin, in the Germán Empire,) and in what manner the
same is to lie performed, to be particularly described and ascertained in and by
the following statement:
:...
This invention relates to pivotted supporting arms for the current collectors of
electrical railway or tramway cars with overhead conductors of the kind described
in the Specification to our Patent No. 18196 of 1894, and it consists in improved
means for readily raising the said arms so as to effect a reliable contact of the
trollies or collecting bars and for lowering them into a horizontal position when
not in use.....
We will describe the present improvements with reference to the accompanying
drawings; in which Fig. 1 shews a "part side elevation of a tram car with the
appliance for raising the said pivotted collector arm. Fig. 2 shews a plan,
Fig. 3 shews 'a side view of the appliance for lowering and maintaining lowered
the pivotted arm. Fig. 4 an end view thereof with the arm in the raised position
Figs. 5 and 6 shew separate views of the positions of the two slotted crank plates
and their rods when the pivotted arm is in the lowered or horizontal position
Fig. 7 shews the same positions of the two crank plates and their rods when
combined, and Fig. 8 shews the positions of the crank plates and their rods when

page_text: the pivotted arm is in the raised position. In the arrangement shewn at Figs. 1
and 2, a a are cranked levers pivotted at a to the carriers of the collector arm
and bearing with their upward bent end against the underside of the pivotted
arm C. To the levers a are attached cords b passing over guide pullies at the ends
of the car, so that by pulling such cords the levers a are raised, and are thereby
made. to raise up the arm C from the horizontal to a certain inclined position.
In order to enable the arm C to be raised from either end of the car whether it
be turned down to the right hand as shewn, or to the left hand, the levers a
are both connected to an endless cord or wire stretched round guide pullies e, so
that a pull exerted on the one lever a will also be transmitted to the other lever.
When the arm C has been raised to a certain extent by the levers a it is
automatically raised to the upright position in contact with the current conductor,
and is maintained in that position by the appliance shewn at Figs. 3 to 8.
On tlie axis of the arm C'are fixed two slotted crank plates A and B, the slots
in which are so formed that when their ends are farthest away from the axis
in a lateral direction a crank pin situated at such ends will be at the greatest
distance from the axis, while when the crank pin shifts along the slot the distance
decreases. Each orank piu in mounted in a grooved roller e that runs in the
slot, and to the pins are pivotted the pull rods & connected to springs. When
the contact arm C is in the vertical position, as at Fig. 8 the slots are slightly
inclined to the horizontal line, and the springs only have a slight teusion put
upon them by the rods and rollers, the latter being situated in the ends of the
slots as shewn at Fig. 8.
When the arm C is moved over to a somewhat inclined position the slots will
be made to approach near to the vertical position, and consequently as the
leverage, with which the one upper and one lower pull rod d acts upon the
springs, will be increased, the springs will he subject to a correspondingly in-
creasing tension, the rollers e still remaining at the ends of the slots.
As the downward inclination of the arm C continues, a position of the slots
will be reached depending upon the arrangement of these, in which the friction
angle of the rollers e in the slots will be exceeded, so that by the pull of the
springs they will then be made to slide or roll inwards in the slots and will assume
a position in which the bars d act on the springs with the shortest leverage, as
shown at Fig. 7.
The arrangement of the slots is such that in this position the springs are
subject to a decreased tension, and the arm C therefore will drop down flat on
to the roof of the car, as at Fig. 3.
It will be seen that when the arm C is turned down to the right hand as at
Fig. 7 it is left hand upper rod d and roller e and the right hand lower red
and roller that operate in the above described manner, the other two rods being
inoperative on account of their slotted connection with the springs.
When it is desired to raise the arm C again, the levers a Fig. 1 are actuated
as above described so as to raise the arm to a certain extent; the rollers e will
thereby be brought into a position in the slots in which they exercise sufficient
leverage to put such a tension on the springs as to cause these to complete the
raising of the arm into the contact position. Figs. 5 and 6 shew the positivas
of the slotted crank plates A B and their pins, rollers c and pull rods d when
the collector arm C is turned down into the horizontal position, the arrows indi-
cating the direction in which the rollers e will have slid during such motion.
Fig. 7 shews the two plates combined in that position, and Fig. 8 shews the
position of the parts when the contact arm C is vertical.
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 collectors for electric railway or tramway cars of the kind herein
referred to, the combination with the axis of the collector arm or support, of

page_text: Perauk plates such as A, B, having slots containing rollers or pins connected to
pull rods such as d that are acted upon by springs, the said slots being so arranged
that when the arm is turned downwards beyond a certain point, the rollers slide
inwards in the slots and thus reduce the tension of the springs, so as to allow
the arm to drop into the horizontal position, substantially as described...
2. In current collectors for electric railway or tramway cars of the kind herein
referred to, the use for raising the current collector arm of cranked levers such
as a operated' by pulls b and connected together by an endless cord or wire passing
round guide rollers, so that the arm can be raised from either end of the car,
irrespective of the position in which it may lie, substantially as described.
Dated this 27th day of September 1897.
ABEL & IMRAY,
Agents for the Applicants.