Year: 1887

page_text: Date of Application, 9th May, 1887
Complete Left, 25th Feb., 1888
Complete Accepted, 29th Mar., 1888
FRANCIS MARSH, Miller, Shingay Mill near Royston Cambs. do hereby declare the
nature of this invention to be as follows:-
This apparatus consists of a ratchet wheel connected on one or more axles, with a
circle lever or part of a circle lever made of Iron, Brass, or any kind of material,
working as a lever with a catch fitted inside the lever, working loosely on to the
ratchet wheel.
This lever or levers are connected with a chain or rope or any kind of suitable
material and is fitted with a spiral or any kind of spring to bring the levers back into
a starting position.

page_text: Facilitating the Starting of Tramway and other Vehicles.
I, FRANCIS MARSH, of Shingay Mill, near Royston, in the county of Cambridge,
Miller, 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:-
This invention has for its object to provide means whereby an increased purchase
may be obtained when starting a tramway or other vehicle for the purpose of reducing
the initial accelerating effort required, and consequently, the stress upon the draught
animals, or other motive agent employed.
that
In apparatus constructed according to my invention one or more. ratchet wheels
are mounted upon an axle or axles of the vehicle and are each enclosed in a drum
carrying a pawl for engaging with the said ratchet wheel. On the periphery of the
drum are two chains or bands leading off in opposite directions, the one being
connected to a draw spring, and the other to a sliding draw bar, in such manner,
when a pull is applied to the said draw bar the drum is rotated through a limited angle,
and the pawl engages with the ratchet wheel and thereby turns the axle through a limited
angle. Whilst the axle is being turned by means of the draw chain the draw bar is
being drawn away from the vehicle so that the point of application of the actuating
force is moving at a greater velocity than the body of the vehicle, and as will readily
be seen, the ratio of these velocities represent the gain in the accelerating effort, and
depends upon the ratio of the diameters of the chain-drum and the wheels of the
vehicles. When the actuating force is removed from the draw-bar the draw-spring
effects the return of the chain drum to its initial position, and by means of suitable
connections disengages the pawl from the ratchet wheel, thus, leaving the vehicle free
to be moved in an opposite direction.
In the accompanying two sheets of illustrative drawings:-
Fig. 1 is a longitudinal sectional elevation of an underframe of a vehicle constructed
according to my invention, and arranged so that it can be drawn in either direction.
Fig. 2 is a plan of the same; and Fig. 3 is a sectional elevation of a part of
an undercarriage shewing the draw bar partly withdrawn, and the pawl engaging
with the ratchet wheel.
Mounted on each of the axles a of the vehicle is a ratchet wheel 6 surrounded by
a chain drum e mounted loosely on the same axle. Secured to the drum c are one
end of each of two chains or belts hi taking off in opposite directions, so that, as the
drum is rotated in either direction one of the said chains is wound on while the other
is wound off the drum. The chain h is secured to a draw bar j, to the end k of which
the motive agent is attached, the said draw bar being free to slide through a limited
distance in a suitable guide or sleeve l. The other chain i is secured to a draw
spring m, which serves to bring back the drum c and draw bar j to their initial
positions when the tension is removed from the draw bar j. The chain-drum c carries

page_text: a pawl or detent d, arranged to engage with the ratchet wheel b when the drum
is rotated in one direction and having fixed on the end of its spindle or pin e a crank or
lever connected to a chain or belt g.
Attached to the crank or leverf on the pawl spindle e before described is one end
of a short chain g whose other end is connected to the draw-spring chain i in such a
manner, that, when the chain drum is in its initial position the pawl chain is taut, and
acting through the pawl crank holds the pawl d free of the ratchet wheel b. When
however a pull is applied to the draw-bar j sufficient to overcome the resistance of the
draw spring, the drum m is caused to rotate, drawing forward the draw-spring chain i,
and slackening the pawl chain 9, which allows the pawl crank f to fall over, and thus
causes the paul to engage with the ratchet wheel b.
It will be obvious that a lever may be used in place of the chain-drum if desired.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. The arrangement of mechanism for facilitating the starting of tramway and
other vehicles, comprising a chain drum or leyer mounted loosely on the axle of the
vehicle, and provided with chains having their ends connected to a draw-spring and a
sliding draw-bar, and with a pawl which engages with a ratchet wheel fixed on the
said axle when the drawbar is pulled forwards, substantially as described.
2. The employment of the pawl-crank and pawl-chain for freeing the pawl from
the ratchet wheel when the draw bar is in its initial position, substantially as
described.
3. The arrangement and construction of apparatus for facilitating the starting
of tramway and other vehicles substantially as described with reference to the
drawings.
WHEATLEY & MACKENZIE,
156, Strand, W.C.,
Agents.