IMPROVED APPARATUS FOR STORING UP POWER FOR ASSISTING IN STARTING AND PROPULSION OF TRAM-CARS AND OTHER VEHICLES ALSO APPLICABLE AS A CONTINUOUS BREAK FOR RAILWAY TRAINS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Robert Heyworth at the Office of the
Commissioners of Patents on the 8th October 1883.
"
THE
ROBERT HEYWORTH of the City of Manchester in the County of Lancaster
'IMPROVED APPARATUS FOR STORING UP POWER FOR ASSISTING IN
STARTING AND PROPULSION OF TRAM-CARS AND OTHER VEHICLES ALSO APPLICABLE
AS A CONTINUOUS BREAK FOR RAILWAY TRAINS
"
This invention relates to the construction of an air pump to be applied to the
axle of a tram car or other vehicle whereby the power required to stop or retard
such vehicle is utilised for compressing air into a receiver and which compressed
air is again used for assisting in the starting of the vehicle and for propelling the
same up hill.
In carrying out my invention I mount a pair of brackets in any convenient
longitudinal position beneath the vehicle and between these brackets I support a
pair of parellel rods which carry the air compressing cylinder and also guide the
cross-heads to which the pistons are connected.
Passing through stuffing boxes at opposite ends of this cylinder are a pair of
trunk pistons or hollow piston rods which again pass through a tubular
compartment supported upon the same parellel rods and provided with stuffing
boxes at each end and are then connected to their respective cross-heads. These
cross-heads are connected by rods to opposite ends of a rocking link mounted
upon horizontal axes at the sides of the cylinder in such a manner that by moving
this link the two trunk pistons are caused simultaniously to approach towards or
recede from each other and thus practically to shorten or lengthen the cylinder and
stroke of the piston.
The ends of this cylinder and the opposite sides of the trunk pistons are in
communication (through suitable inlet and outlet valves) with the bottom of the
air compression chamber into which sufficient oil or glycerine or other liquid is
introduced to ensure the space between such pistons and the ends of the cylinder
being always filled with such liquid and thus to ensure such pistons remaining

page_text: stationary in any position in which they may be placed owing to an equal pressure
being behind them.
Between these trunk pistons in the cylinder is the main air compression piston
the rod of which passes through the hollow rod or trunk of one of the trunk
pistons and through a stuffing box in its cross-head and is then connected to the
main cross-head which in turn and by means of side links is again connected to a
radial alotted link oscillating upon horizontal bearings. This slotted link is
connected by a connecting rod to a crank upon the axle of the vehicle in such
a manner that when the extremities of the side links are in the centre of the radial
slot no motion of the piston or other mechanism takes place but immediately the
side links are raised or lowered in the slot a rocking motion is imparted to the
side links and a corresponding reciprocating motion is given to the main piston.
The air compressing cylinder is further in communication through the tubular
compartments hereinbefore mentioned and through slots or ports in the hollow
piston rods or trunks opening into such compartments with the upper part of the
air compressing chamber-suitable valves being provided between the chamber
and cylinder and operated simultainously by an excentric upon the axle of the
vehicle.
By now connecting the rocking link on the side of the cylinder with one arm
of a bell crank three armed lever working in horizontal bearings and connecting
the second arm of this lever to a pair of vertical links suspended from the side
links and again connecting the third arm of this lever to a sliding bar operated
by a hand lever the lengthening and shortening of the stroke of the piston can
be effected instantly and simultainously with the setting in motion of the air
compressing piston whilst on the other hand by reversing such lever the
compressed air stored up can be allowed to exercise any degree of pressure or
power upon the main piston and thence on to the crank and axle of the vehicle at
pleasure I prefer to construct the air compressing chamber in compartments so
that the first compartment is first charged quickly with compressed air and then
when a desired pressure is reached the over-plus shall pass into the other
compartments and thus ensure that a high pressure shall always be in reserve and
quickly maintained, in other words that the quantity of air compressed in the
act of stopping the vehicle shall always be sufficient to effect the starting of the
vehicle.
This construction of apparatus is also applicable for assisting in the starting of
railway trains and as a continuous break
In order to indicate to the driver say of a tram car the amount of declivity or
rise of the tram rails and thus inform him of the position in which to place his
hand lever I arrange a segmental dial having a finger which either always
maintains a vertical position by its own gravity whilst the dial partakes of the
angle of the declivity or the dial may be stationary, and the finger revolve by
arranging it in connection with a float working in quick-silver contained in one of
a pair of vertical branches at the extremities of a pipe lying longitudianly across
the two axles of the vehicle.