Year: 1885

page_text: I, GEORGE EDWARD DEHANY, of 33 Claud Road, Townsend Lane, West Derby,
Liverpool in the County of Lancaster, Contractor, do hereby declare the nature of
this invention to be as follows:-
This invention relates to improvements in machinery or apparatus employed for
actuating tram-car brakes, for which purpose I employ a pump and a small
hydraulic cylinder or cylinders.
The hydraulic cylinders are hereinafter called brake cylinders and may be placed
midway between and in a direct line with each pair of car wheels. They are
suitably formed for bolting to the body of the car and are provided with a pair of
pistons and piston rods or rams which extend through lids or guides at the ends of
the brake cylinders, and are of sufficient length to allow of short links being
pivotted thereto.
The other ends of the short links may be attached directly to the brake blocks,
which may be suspended or hung in the ordinary way from the body of the car.
The two brake cylinders are connected together by a supply pipe which admits of
the actuating fluid entering between the two sets of pistons, or rams, to cause
them, together with the brake blocks, to recede from each other, thus bringing the
brake blocks in contact with the car wheels, and by withdrawing the actuating
fluid by the pumps the blocks are caused to move towards each other thereby
taking off the brakes. To the before mentioned pipe another one is attached that
opens communication with the before mentioned pump or pumps which may be
somewhat larger in diameter than the brake cylinders and be placed close to the
driver. The rod or spindle may be screw threaded and be provided with a hand-
wheel having a screw threaded boss, to serve as a nut, or other convenient means
may be used, so that by turning a handle or hand wheel, somewhat similar to those
at present in use, in one direction the pump will cause the actuating fluid to press
on the brake pistons and if the handle or hand wheel be rotated in the opposite
direction the fluid will be by the action of the pump withdrawn from between the
pistons or rams thus causing them to move towards each other.
The pumps may be provided with the necessary relief valve charging holes also
a small reservoir and supply pipe and valve for collecting and returning any liquid
that may have leaked from the pumps may be provided.

page_text: The pistons may be furnished with any suitable packing such as double cupped
leathers, or cupped leather glands may be used with solid rams.
Suitable springs may be employed for forcing the brake pistons or rams towards
each other when the actuating fluid is withdrawn to release the brake.
With some classes of cars one hydraulic brake cylinder and two pistons or rams
may be employed in place of two brake cylinders as before described and a pump
with the necessary band gearing may be placed at each end of the car so that the
brake may be under the control of both the driver and the guard.
I would have it understood that apparatus of the kind referred to may be con-
structed in modified forms to suit different classes of tram cars without departure
from the essential features of my invention.
I GEORGE EDWARD DEHANY of 83 Claude Road, Townsend Lane, West Derby,
Liverpool, in the County of Lancaster, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:―
This invention relates to improvements in machinery or apparatus employed for
actuating tram-car brakes, for which purpose I employ a pump, and a small
hydraulic cylinder or cylinders.
Referring to the accompanying sheet of drawings Fig. 1. is a side elevation
partially in section. Fig. 2. is an end elevation in section taken on line A. C
of Fig. 1. Fig. 3. is a plan or top view, shewing one of the hydraulic brake
cylinders in section on line A² A³ of Fig. 1. whilst the other cylinder is shewn in
dotted lines, bolted to the body, or frame of the car. Fig. 4. is also a plan or top
view shewing a modified form of brake, in which only one cylinder is employed
instead of two.
In the drawings there is shewn only sufficient of the tram car body as to fully
illustrate and make my invention clear,

page_text: The hydraulic cylinders A. A. hereinafter called the brake cylinders, are
according to the arrangement shewn by Figs. 1. 2 and 3. placed midway between
and in a direct line with each pair of car wheels B. B. They are suitably formed
for bolting to the frame, or body of the car C. and are each provided with a pair
of pistons D. D. and piston rods or rams E. E. which extend through lids or
guides F. F. secured to the ends of the brake cylinders A. A. and are of sufficient
length to allow of suitable vibrating, or coupling links G. G. being pivotted
thereto.
According to the arrangement shewn in Figs. 1. 2 and 3. the other ends of the
links G. G. are pivotted directly to the brake blocks H. H. which may be suspended
or hung in the ordinary way, by links I. I. from the body or car frame C.
The two brake cylinders A. A. are connected together by a supply pipe A¹ which
admits of the actuating fluid entering between the two sets of pistons or rams
D.D.
to cause them, together with the brake blocks H. H. to recede from each other, thus
bringing the brake blocks in contact with the car wheels B. B. and by withdrawing
the actuating fluid by a suitably formed pump (placed on the footboard close to the
driver) the blocks are caused to move towards each other thereby taking off 'or
releasing the wheels.
The connecting pipe A¹ has another pipe A³ attached, which opens communi-
cation with the before mentioned pump J. which is made somewhat larger in
diameter than the brake cylinders A. A. so that its piston K. shall have a short
stroke and be quick in action.
The spindle or pump rod K' is screw threaded with a coarse thread as shewn,
and takes into the internally screw threaded hole in the pump cover L. Fig. 1. It
is provided with suitable means, such as a hand wheel or the handle K' by which
it' may be rotated to move the piston K. By turning the hand wheel or handle K'
in one direction the fluid will press with an equal pressure on the brake pistons
which will regulate themselves to suit the different thicknesses of brake blocks
employed, whilst by turning the hand wheel or handle Ks in the opposite direction
the pump J. will suck or withdraw the actuating fluid from between the
pistons D. D. thus bringing them towards each other.
To assist in bringing the brake blocks H. H. clear of the wheels B. B. suitable
spiral or other form of springs M. M. may be employed, one end of each being
attached to the distance or stay bar N. whilst the other end is secured to the brake
cylinder A. as shewn in Fig. 3. By this arrangement it becomes impossible for one
of the sets of pistons D. D. to travel back the full distance allowed by the with-
drawal of the actuating fluid whilst the other set of pistons remain stationary.
The barrel of the pump J. may be made long enough to allow of its piston K.
having sufficient length of stroke or travel, to actuate the brake pistons after a
portion of the fluid has leaked past the pistons. The space between the upper side
of the pump piston K. and the lid L. may form a reservoir for charging or
replenishing any leakage that may take place. A small charging pipe and valve P.
is provided, for opening communication between the upper and lower side of the
pump piston K. so that when it has worked to the full extent and bottom of its
stroke, by filling the reservoir through suitable holes left in the lid L. and turning
the hand wheel or handle K' so as to bring the pump piston upwards the actuating
fluid will simultaneously flow down the pipe, and through the valve P. until the
pressure pump is charged. Then the valve is closed and the pump is again ready
for action.
In any convenient position a small relief valve (not shown) may be provided on
the pump and may be loaded to the required pressure, so that a higher or
dangerous pressure cannot be attained.
The pistons may be furnished with suitable packing, such for example as cupped
leathers, as shewn, or cupped leather glands may be used with solid rams.
The size of the brake cylinders will somewhat vary in diameter according to the
different makes and weights of the cars,

page_text: For certain classes of cars it is advisable to employ only one brake cylinder A. as
shewn in outline plan Fig. 4. The cross bar, or stay rod N. is made sufficiently
strong to withstand the pressure exerted by the pistons. The single brake
cylinder A. is made of considerably larger diameter than when several cylinders
are employed.
When desirable one of the before mentioned pressure pumps J. may be placed at
each end of the car, so that the brake may be under the control of either the driver
or guard. The actuating fluid may be chemically prepared so that it shall not freeze
under ordinary temperatures.
Suitable charging, or air valves may be provided on the pipes A¹ or A' or other
convenient position,
I would have it understood that apparatus as above described may be modified
to suit the requirements of different classes of tram cars or similar vehicles without
departure from the essential features of my invention.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same may be applied I would have it under-
stood that what I claim is :-
1. In machinery or apparatus for actuating tram car brakes a hydraulic brake
cylinder having two pistons or rams one connected to one brake block or set of
brake blocks, and the other to another brake block, or set of brake blocks, substan-
tially as described and shewn in the drawings.
2. In machinery or apparatus for actuating tram car brakes, the employment of
a pump, worked by hand, by the driver, or other attendant, to obtain the required
pressure, substantially as described and illustrated in Fig. 1.
3. The improved brake apparatus for tram cars constructed, arranged, and
operating substantially as described with reference to Figs. 1. 2. 3 and 4. of the
drawings.
Dated 18
augus
1000
GEORGE EDWARD DEHANY.
Witness,
F. M. C. SCOTT,
Patent Agent,
89, Victoria Street, Liverpool..