IMPROVEMENTS IN TRACTION AND LOCOMOTIVE ENGINES
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by William Henry Dorman and
Charles Cowper at the Office of the Commissioners of Patents, with
their Petition, on the 7th June 1859.
We, WILLIAM HENRY DORMAN, of Winchester House, Old Broad Street,
in the City of London, and CHARLES COWPER, of 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Patent Agent, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN TRACTION AND
LOCOMOTIVE ENGINES," to be as follows:-
In order to relieve the engine from jolts and concussions, and to enable it to
turn corners with facility, we mount it upon springs, and we cause the front
wheels to "lock" or turn in the ordinary manner. To communicate the
motion to the driving wheels, and yet to allow of the play of the springs, we
place a horizontal shaft on the engine, parallel to and at or about the same
level as the main axle of the driving wheels. On this shaft are two cranks
placed at right angles to each other, and connected by connecting rods to two
similar cranks on the main axle. The shaft and the main axle are thus
caused to revolve at the same velocity, while the springs are free to act. The
shaft is driven by geering from the crank shaft of the engine, with or without
an intermediate shaft or shafts, and the speed is reduced by the geering in any
convenient manner. Or we employ two toothed wheels or pinions of different
diameters sliding on one shaft, and capable of being put into geer with two
other wheels on the other shaft. On the main axle we apply a combination
of three or four bevil wheels, which is sometimes called a "jack-in-the-box,"

page_text: Each driving
or differential box. One or two of these bevil wheels are carried round by the
axle, and carry with them the other two bevil wheels fixed on or connected to
the wheel boxes or naves of the two driving wheels respectively. Both wheels
are thus driven; but if one is stopped or retarded, the other one is still driven,
and the engine is thus enabled to turn corners with facility.
wheel may have a separate axle with two cranks, and may be driven by two
connecting rods from two other cranks, these last cranks being actuated
through the intervention of the jack-in-the-box; any combination of wheels
having the same effect as the jack-in-the-box may be substituted for it. We
also construct the jack-in-the-box with more than two intermediate wheels or
pinions between the two main bevil wheels, instead of only one or two, as in
the ordinary arrangements of the jack-in-the-box, and we thus obtain much
greater strength by dividing the strain among several wheels or pinions; and
we can also use fewer and stronger teeth in each pinion. We also effect the
same object of communicating the motion to the wheels while the engine and
boiler are supported by springs, by means of an endless chain or chains in the
following manner :-We mount a large chain wheel or pulley on the main
axle, or attach it to the jack-in-the-box, or directly to the driving wheel or
wheels, and we mount a smaller chain wheel or pulley on the crank shaft of
the engine. We pass an endless chain round these two wheels, but we also
carry the chain round another wheel or wheels mounted on the engine or
frame, and so arranged that the upper and lower straight parts of the chain
leading to and from the aforesaid large chain wheel may be parallel, or nearly
so, and horizontal, or as nearly so as may be convenient. By this arrange-
ment the play of the springs does not communicate any injurious jerks or
concussions to the crank shaft and connecting rods, as would be the case if the
straight parts of the chain were simply tangents to the large and small chain
wheels, and therefore not parallel to each other. One convenient arrangement
consists of three small chain wheels at different levels. The chain passes
horizontally from the top of the large wheel over the first or upper sinall
wheel, and from this to the second or middle small wheel, and then round
the third or lower small wheel, and thence horizontally to the bottom of the
large wheel. One of the small wheels, as, for example, the upper one, is
mounted loose on the crank shaft, to which it can be connected by a clutch..
The crank shaft carries a pinion, which drives a wheel on the spindle of the
second chain wheel, which is also provided with a clutch to connect it to this
spindle. Thus, when this clutch is connected, and the first disconnected, the
chain will be driven with a slow motion by the second chain wheel, but when
this clutch is thrown out, and the first clutch thrown into geer, the chain will

page_text: be driven with a faster motion by the first chain wheel. The lower chain
wheel or pulley may be mounted in a slide, and drawn back by a screw or
otherwise to tighten the chain. It may also be driven either at the same rate
as the other chain wheels, or at a still slower speed if three different motions
should be required. This apparatus may be placed on both sides of the
engine to drive both or either wheel separately, or it may drive by means
of a jack-in-the-box, as already mentioned. The position and proportion of
the wheels admit of great variations; but in each case the power is com-
municated from a small chain wheel or pulley to a larger one; and the
straight parts of the chain are parallel and horizontal, or nearly so, at the
parts leading from the machinery, which is carried by the springs to that
which is not carried by springs. Thus, the chain may pass in a parallel and
horizontal direction from one small chain wheel on the crank shaft, over or
under, or between two other wheels or guide pulleys, and thence round the
large wheel, such guide pulleys being mounted on a frame, or otherwise so
connected to the main axle as to move with it. One of the small chain wheels
may be on the crank shaft, as already mentioned, or it may be on another
shaft, and may be driven by geering or otherwise from the crank shaft. The
driving wheels which we prefer to employ are those described in the Speci-
fication of certain Letters Patent granted to William Bray, and dated the 31st
day of December, One thousand eight hundred and fifty-six, No. 3102.
When the blades of these wheels are governed by an eccentric, and it is
wished to give elasticity to their action, we place a metal ring round the
eccentric, and a larger metal ring outside the first ring, and we place springs
or a ring of vulcanized caoutchouc between the two rings, and we connect the
rods from the blades to this outer ring. A similar effect may be produced by
applying a separate spring to each blade, but we consider the first arrange-
ment to be preferable; or the eccentric itself may be mounted on a spring or
springs, or on a lever governed or regulated by a spring. We employ a boiler
of the ordinary form used for locomotive engines on railways, but with a
shorter barrel and shorter tubes than are generally used; and we place the fire
box between the axle of the driving wheels and the fore-axle, and with the
barrel of the boiler over the axle of the driving wheels, by which means the
whole or the greater part of the weight of the boiler may be caused to bear
on this axle. We apply a fan or blower or exhauster to maintain the draught
of the fire, and we are thus enabled to dispense with the chimney, or to reduce
its size, and also to employ small tubes in the barrel of the boiler so as to
efficiently extract the heat from the products of combustion, notwithstanding
the shortness of the tubes. We place the crank shaft and geering between

page_text: the two axles, or we place them behind the main axle, and in some cases we
dispense with the separate crank shaft and geering, and we connect the con-
necting rods of the engines directly to the two cranks on the main axle; or
we employ the first-mentioned system of cranks and connecting rods to com-
municate the motion to a pinion or pinions, which geer into a wheel or wheels
on the main axle, or on the jack-in-the-box, or on the driving wheels.