Improvements in Apparatus for Stopping and Starting Tramcars and similar Conveyances.
Year: 1889

page_text: Date of Application, 23rd Sept., 1889-Accepted, 5th Apr., 1890
COMPLETE SPECIFICATION.
Improvements in Apparatus for Stopping and Starting Tramcars
and similar Conveyances.
I, EDGAR DREDGE, of Rosebank, Park Villas, Albion Road, Stoke Newington, in the
County of Middlesex, 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 :-
The object of this invention is to provide apparatus for stopping tramcars and
similar conveyances, and for restarting them by the power (from whatever source
derived) stored up during the stopping of the vehicle, and the invention consists in
certain improvements on the apparatus for which Letters Patent were granted to me
dated September 30th 1887, No. 13265.
The arrangement of the apparatus, as described in the specification of the said
Patent, is open to certain objections which the present invention is intended to over-
come. It also contains, as an essential feature, the combination with the car-starting
mechanism, of brake mechanism, so that the powerful influence of the impetus of the
car can be also brought to bear on the brakes, whereby the stopping of the car is
caused automatically, effectually, and promptly, at whatever speed the car may be
progressing.
In the accompanying drawings, Fig. 1 is a longitudinal section of a tram-car with
my apparatus adapted thereto.
Fig. 2 is an underside plan view: Fig. 3 is a transverse section taken on the
line, a, Fig. 2; and Figs. 4 and 5 show details which will be more particularly
referred to hereafter.
A is the frame of the car, B B¹ are the axles of the running wheels C, and D is a
brake lever of the ordinary construction, and which may be actuated by the driver in
the usual manner, when desired. E is. a drum mounted loosely on the axle B, and
forming one part of a friction clutch of any convenient construction, and E' is the
other part of the clutch which slides: on the axle B on a feather. The part Elis
thrown into gear with the part E by means of the fork F, actuated through the
connecting link 1, crank 2, rock shaft 3, toothed sector 4, and the worm wheel 5, on
the rod or spindle of a hand wheel within reach of the driver, or in any other
convenient manner.
Attached to the drum E are a pair of chains G, which extend beyond the axle B',
and are secured to a cross-head or bolt forming one end of an open link chain H (see
the detached view Fig. 4). The other end of this chain is secured to a second cross-
head H, which may slide on guide rods H, and attached to a spring or springs H³,.
secured to the frame A of the vehicle.
The open link chain H passes between guide pulleys I, suitably arranged to maintain
the chain in its proper position.
Upon the axle B', between the chains G, is mounted a pawl and ratchet
coupling JJ, shown detached at Fig. 5; or it may be a silent clutch, as shown
in the drawing of the patent before referred to. This coupling consists of a
flanged disc wheel J, mounted loosely on the axle B', having round its outer
periphery, gear teeth, and carrying, inside, one or more pawls.
Jis a second flanged wheel keyed on the axle B' within the wheel J, and having,
on its outer periphery, ratchet teeth, with which the pawls of the wheel j
engage. It
will thus be seen that the part J will be free to rotate on the axle B₁ in one direction
only.
The driver, when desiring to stop the car, throws the clutch E, E', into gear,
and causes the drum to wind up the chains G, under the influence of the
momentum of the car. The link chain H is thus drawn out, and the springes H
distended.
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page_text: As the chain H comes into contact with the teeth of the wheel J, this wheel will he
rotated in the direction opposite to that in which the car is proceeding, and the
chain will assume the position shown by the dotted line, Fig. 1.The chain, when
extended, will be, so to speak, in equilibrium, as the friction clutch E, E, may be said
to be pulling one way, while the tendency, of the silent or pawl clutch.J J' is to pull
the other way.
The pawl wheel J, in fact acts as a pawl to the drum E of the friction clutch E, E',
when, winding up, so that, so long as the friction clutch is in gear, there can be no
running back of the chain Hunder the influences of the springs.
To start the car, the driver releases the clutch E, D, and the springs will pull back
the chain H. This will cause the wheel J, with which the chain is in gear, to rotate
in the direction in which the car is to proceed, and, by reason of the pawland ratchet
arrangement, it will also drive the axle B in the same direction, and ilius-start
tlie car:
As the chain His pulled out during the stopping of the car, the crosshend H¹ will.,
strike against, and push forward another crosshead K, which may also slide on the
guide rods-, and is attached by a chain K (which passes round a guide pulley) to
the chain of the ordinary brake lever D. Thus it will be seen that the act of storing
the power, during the stopping of the car,
will also put on the brakes, and as, the
power is produced by the impetus of the car, the action of the brakes will be infinitely
more powerful than when worked by the driver.
It is necessary, for the starting of the car, that the brakes should be "off"
immediately the clutch E is released. To effect this object, I may place, upon the...
guide.rods H2, outside the crosshead K, springs, K, which will be compressed as the
brakes are put on, but will drive back the crosshead the moment the clutch E is
released, and so release the brake.blocks.
It will be evident that the arrangement of brake apparatus above described,
can be combined with the car-starting apparatus referred to in the patent before-
mentioned.
The springs H³, shown in the drawing, are-india-rubber springs, but any other
springs, or any other source of power, may be used without departing from my
invention.
It will also be evident that the apparatus will be duplicated and reversed, so
that one or other may be used according to the direction in which the car is
proceeding..
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
claiin is
1. In car-starting apparatus, the combination of a friction clutch on one axle, with
an open link chain which is drawn out (against the tension of a spring or otherwise)
by a drum on the said clutch, and a silent clutch or pawl and ratchet coupling on the
other axle, as and for the purpose set forth. :
2. The arrangement of car-starting apparatus, as herein shown and described.
3. The combination with a car-starting apparatus, of a brake imechanism, whereby
the momentum of the vehicle which is used to set the starting mechanism, serves also
to actuate the brake mechanism, as set forth.
4. The arrangement of car-starting apparatus herein shewn and described, fin com
bination with the ordinary, brake mechanism of tramcars.
Dated this 23rd day of September.1889.
J
NEWTON & SON,
Agents for the Applicant.
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