potor Propelled Koad vehicles.
Year: 1898

page_text: potor Propelled Koad vehicles.
I, ERNEST LATHAM, of 3, Berlin Road, Catford, in the County of Kent,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has reference to improvements in motor propelled vehicles suit-
able for use on roads, objects being to dispense as far as possible with gearing or
chains between the engines and the driving axles and to so construct and arrange
the motive power apparatus that an extra amount of power may be applied to the
driving wheels at any desired time, for instance when starting or going up hill
without any change of gearing, and that the working of the said apparatus shall
cause comparatively little vibration or shaking of the vehicle.
In one construction, the underframe of the vehicle may conveniently be built
up of oak or other wooden beams sandwiched between iron or steel plates secured
by bolts or rivets that pass through distance tubes or ferrules inserted in the
wood; or the frame may be of steel plates stiffened by angle bars or flanges.
The underframe is provided towards its rear part with horn plates fitted with axlo
boxes which bear against springs and in which run the axles of a pair of driving
wheels. one of which is keyed at one end of a solid axle that extends from side
to side of. the vehicle and the other of which is keyed upon the outer end of a
sleeve or hollow axle that is mounted so as to turn freely about said solid axle,
and the two axles are connected together by means of a "Jack-in-the-box" or
differential gear comprising a bevel wheel keyed to each axle, both of which
gear with one or more bevel wheels carried by axes forming radii of a spur wheel,
that is driven from the engine shaft through suitable spur gearing. In order to
maintain the spur wheels properly in gear, the engine shaft and the axles of
the driving wheels are coupled by one or more links in which the axles of any
intermediate gear wheels used are mounted and which permit the driving wheel
axles to move vertically in their axle boxes.
The engine I prefer to employ is a compound steam engine, the piston strokes,
and consequently the cranks, of which are unusually long, as, with such an
engine, a good piston speed may be obtained with a low rate of revolution and
the necessity of employing complicated speed-reducing or power-increasing gear
obviated, whilst, at the same time, the vibration common to high speed engines
is avoided. Conveniently the engine comprises oscillating high pressure and low
pressure cylinders mounted, one at each side of the vehicle, and having their
pistons connected to long cranks fixed to the ends of the engine shaft outside
the frame of the vehicle and set at such an angle to each other that the piston
of the low pressure cylinder will have made about one quarter of its stroke before
steam is allowed to exhaust from the high pressure cylinder into the low pres-
sure cylinder. The distributing valves are so arranged as to admit steam behind
the high pressure piston until it has almost completed its stroke and to allow
steam to exhaust from the high into the low pressure cylinder during the whole of
the last three quarters (more or less) of the stroke of the piston of the latter. Each

page_text: of the cylinders oscillates on trunnions carried by one of its cylinder covers in
which the distributing valve is fitted; the valves of the two cylinders are simi-
larly arranged and each is operated by the motion of its respective cylinder.
Each valve spindle, which conveniently extends at right angles to the axis of
oscillation, is fitted with a block that moves to and fro in a curved guide, the
angular position of which can be varied as required. The two curved guides are
carried by a common rock shaft provided with a hand lever. The steam pipes,
and connections between the two cylinders and the steam supply are so arranged
and provided with suitable cocks or valves that high pressure steam may be
admitted direct to the low pressure cylinder during practically the whole length
of the stroke of its piston. To enable this to be done the valves are so arranged
as to keep the admission ports of both cylinders uncovered during the full piston
strokes both when the engine is worked as a simple engine and also when worked
as a compound engine; in the latter case it is the valve of the high pressure
cylinder that controls the period at which steam commences to pass from one
cylinder to the other.
In working an engine as hereinbefore described the temperature and pressure of
the steam is so far reduced before it is exhausted from the low pressure cylinder
that it can be allowed to escape without noise into the atmosphere or, at any
rate, only a comparatively small condenser is needed.
The steam boiler employed may be of any convenient type, for instance, &
water tube boiler.
I prefer to employ a condenser comprising a cooling-water reservoir, a chamber
into which the steam is discharged and to which water is led from the said reser-
voir and a series of depending tubes connecting such chamber with a lower
collecting chamber in which the mingled condensation water and the cooling
water is received. In one construction, the reservoir and the steam and water
chamber are combined in one tank but separated by a false bottom. The tubes
extend some distance above the bottom of the said steam and water chamber and
are formed some distance from their upper ends with perforations through which
the water can flow whilst the steam enters the tubes through their upper open
ends. The admission of cooling water to this chamber is regulated by a cock or
otherwise so as to prevent it rising above the tops of the tubes. From the lower
part of the collecting chamber a pipe leads to the suction of the boiler feed pump,
whilst from the upper part of this chamber another pipe leads to the suction of a
circulating pump the discharge of which leads to the cooling-water reservoir.
By this arrangement before the surface tubes can become sealed by water the
circulating pump will come into action and maintain a clear passage through
the tubes for the steam. The plungers of both these pumps are conveniently
connected to arms on a common rockshaft driven by an eccentric on the engine
shaft. In such a condenser the steam is condensed partly by the water jets and
partly by contact with the air cooled surfaces of the tubes. A suitable pipe is
provided through which the exhaust can, when desired, be led to the chimney of
the boiler or into the open air direct, instead of through the condenser.
In another construction, the vehicle is provided with only one driving wheel
the axle of which is journalled in suitable bearings fitted in horn-plates arranged
near the rear end of the vehicle. The single driving wheel is placed in the
centre of the width of the vehicle so that in turning on the road it forms the
centre of motion and no Jack-in-the-box" is required, as is the case when there
are two driving wheels arranged at a distance apart from each other. The engine
cranks are fixed to the axle of the driving wheel preferably outside its bearings.
On each side of this driving wheel there is on a stud or axle a steadying wheel.
The springs of the driving wheel are much stiffer than those of the steadying
wheels, so that the greater portion of the weight of the rear part of the vehicle
is borne by the driving wheel and the adhesion necessary for traction thus
obtained:
The fore carriage and steering arrangements may be of any convenient kind and

page_text: the driving platform is preferably in front of the boiler and the -controlling
mechanism of the motive power, brake and steering apparatus is arranged within
easy reach of the driver and preferably in front of him.
Dated this 6th day of July 1898.
Improvements in Motor Propelled Road Vehicles.
I, ERNEST LATHAM, of 3, Berlin Road, Catford, in the County of Kent,
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:-
This invention has reference to improvements in motor propelled vehicles suit-
able for use on roads, objects being to dispense as far as possible with gearing or
chains between the engines and the driving axles and to so construct and arrange
the motive power apparatus that an extra amount of power may be applied to the
driving wheels at any desired time, for instance when starting or going up hill
without any change of gearing, and that the working of the said apparatus shall
cause comparatively little vibration or shaking of the vehicle.
Referring to the accompanying illustrative drawings,
Fig. 1 is a side elevation of a motor-propelled omnibus which is designed to
carry twelve persons inside; Fig. 2 is a plan view of the same, the lower half of
the figure having the car body removed; Figs. 3 and 4 are enlarged cross sections
on the lines a a and b b Fig. 1 respectively.
In this construction, the underframe 1 of the vehicle is built up of oak or
other wooden beams sandwiched between iron or steel plates secured by bolts or
rivets that pass through distance tubes or ferrules inserted in the wood, but it
may be of steel plates stiffened by angle bars or flanges. The underframe 1 is
provided towards its rear part with horn plates 2 fitted with axie boxes 3 which
bear against the pins. or lugs extending from the buckles of springs 4 and in
which run the axles 5,5" of a pair of driving wheels 6, 6"; the wheel 6 is keyed
at one end of a solid axle 5 that extends from side to side of the vehicle and the
other wheel 6 is keyed upon the outer end of a sleeve or hollow axle 5" that is
mounted so as to turn freely about said solid axle 5. The two axles 5 and 5ª are
connected together by means of a Jack-in-the-box" or differential gear com-
prising bevel wheels 7, 7ª keyed to respective axles and gearing with one or more
bevel wheels 8 carried by, axes 9 forming radii of a spur wheel 10, that is driven
from the engine shaft 11 through suitable spur or other gearing 12. In order
to maintain the spur wheels properly in gear, the engine shaft and the axles of
the driving wheels are coupled by links 12 in which the axles of the intermediate
gear wheel 12 is mounted and which permit the driving wheel axles to move
vertically in their axle boxes.
..
Instead of connecting the axles 5, 5° by means of a Jack-in-the-box" they
may be geared by chains and sprocket wheels to the respective portions of a
divided shaft, which portions are connected by a "Jack-in-the-box
driven from
the engine shaft. Or the driving wheels may be mounted on the ends of a fixed
axle in the same manner as in ordinary horse vehicles and be driven by chains
from sprocket wheels on the ends of the "Jack-in-the-box" shaft.
The engine I prefer to employ is a compound steam engine, the piston strokes,

page_text: and consequently the cranks, of which are unusually long, as, with such an
engine, a good piston speed may be obtained with a low rate of revolution and
the necessity of employing complicated speed-reducing or power-increasing gear
obviated, whilst, at the same time, the vibration common to high speed engines
is avoided. In order to obtain the required power without the use of gearing the
cranks may even be as long as, or longer than, the diameter of the driving
wheels.
The engine shown comprises oscillating high pressure and low pressure
cylinders 13 and 14 mounted, one at each side of the vehicle, and having their
piston rods 13, 14" connected to long cranks 15 fixed to the ends of the engine
shaft 11 outside the frame of the vehicle and set at such an angle to each other
that the piston of the low pressure cylinder 14 will have made about one quarter
of its stroke before steam is allowed to exhaust from the high pressure cylinder
into the low pressure cylinder. Fig. 5 is a longitudinal section of one of the
cylinders viz. the high pressure cylinder 13; Fig. 6 is an end view thereof with
the cover of the valve chest and the valve removed; and Fig. 7 is a section of
part of the cylinder taken in a plane containing the axes of the cylinder and its
trunnions. 16 is the steam inlet; the cylinder end is formed with a valve face
in which there are three ports, one 17 of which leads to the steam inlet 16, and
the other two 18 and 19 of which respectively lead to opposite ends of the
cylinder; 20 is the exhaust steam outlet through which steam passes to the steam
pipe of the low pressure cylinder or to the atmosphere, as the case may be. 21 is
the distributing valve; that of the high pressure cylinder is so arranged as to
admit steam behind the high pressure piston until it has almost completed its
stroke and to allow steam to exhaust from the high into the low pressure cylinder
during the whole of the last three quarters (more or less) of the stroke of the
piston of the latter. Both cylinders are similarly constructed and, as will be
seen from the drawings, each oscillates on trunnions carried by one of its covers
in which the distributing valve 21 is fitted; the valves 21 of the two cylinders
are similarly arranged and each is operated by the motion of its respective
cylinder. Each valve spindle 22, which conveniently extends at right angles to
the axis of oscillation, has fixed to it a block 23 (Figs. 1 and 3) that moves to
and fro in a curved guide 24, the angular position of which can be varied as
required. The block can slide lengthwise upon a pin 23" (Fig. 5) projecting
from the cover. The two curved guides are carried by a common rock shaft 25
provided with a hand lever 26.
"
"
66
The steam boiler 27 may be of any convenient kind, for instance, an oil fired
water tube boiler comprising an annular lower water chamber connected to, a
centrally arranged upper steam vessel by a series of water tubes between which
the hot gases from a central combustion chamber to a smoke" box around their
upper portions. Although I have indicated a boiler of this type having a central
funnel or chimney, connected with the
smoke"
box, which encloses the steam
vessel, I prefer the smoke box to terminate about the level of the bottom of
said steam vessel and to lead off the gases therefrom by means of several chimneys
arranged around the steam vessel; the "smoke" box roof may consist of a couple
of approximately semi-annular plates, which are formed with apertures to which
the chimneys are fitted in such a manner that the plates can easily be removed
for cleaning purposes. The boiler is slung or supported by two or more straps 27"
from the side frames; 27b are oil tanks. 28, 28° are steam supply pipes and
29 the connecting pipe between the two cylinders 13 and 14. 30 is a cock on a
branch 13 leading from the pipe 29 to the condenser, boiler chimney, or silencer
and 30 is a three-way cock controlling the passage through the pipe 29 and also
communication between the right hand part of said pipe and the steam pipe 28*.
The levers of the cocks 30 and 30" are connected by a cranked link 30b and are
operated simultaneously by a hand lever 30° so as to allow exhaust steam from
the cylinder 13 to pass through the cock 30 and high pressure steam from the
pipe 28 to pass direct to the cylinder 14 through the cock 30%, or to cause

page_text: exhaust steam from the low pressure cylinder 13 to pass to the high pressure
cylinder through the pipe 29. To enable high pressure steam to be admitted
direct to the low pressure cylinder during practically the whole length of the
stroke of its piston, the distributing valves 21 are so arranged as to keep the
admission port of each cylinder uncovered during the full stroke of its piston,
both when the engine is worked as a simple engine and also when worked as a
compound engine; in the latter case it is the valve 21 of the high pressure
cylinder that controls the period at which steam commences to pass from one
cylinder to the other.
The condenser may be of the kind illustrated in Figs. 8 and 9; it comprises a
cooling-water reservoir 31", a chamber 31b into which the steam is discharged
from an exhaust pipe 31° and to which water is led by a pipe 31d from the reser-
voir above and a series of depending tubes 31° connecting the chamber 31b with a
lower collecting chamber 31' in which the mingled condensation water and the
cooling water is received. The tubes extend some distance above the bottom of
the chamber 31b and are formed some distance from their upper end with per-
forations through which the water can flow, whilst the steam enters the tubes
through their upper open ends. The admission of cooling water to this chamber
is regulated by a cock 31 or otherwise so as to prevent it rising above the tops
of the tubes. From the lower part of the collecting chamber 31 a pipe 32 leads
to the suction of the boiler feed pump 33, whilst from the upper part of this
chamber another pipe 34 leads to the suction of a circulating pump 35. Before
the tubes 31° can become sealed by water, the circulating pump 35 will come
into action and maintain a clear passage through the tubes for the steam. The
circulating pump may be fitted with a long line of discharge pipe 35* so
arranged about the roof or other part of the vehicle as to cool the water passing
through it before delivering it to the tank 31. The plungers of these two pumps
are conveniently connected to arms 33 and 35° respectively on a common rock
shaft 36 driven from a pair of eccentrics 37 on the engine shaft. The reser-
voir 31 is charged with cooling water through a pipe 31 which can have a cap
or a funnel fitted to it. In such a condenser the steam is condensed partly by
contact with the air cooled surfaces of the tubes 31° and partly by the water jets
passing through them. A suitable pipe (not shown) is provided through which
the exhaust can, when desired, be led to a silencing tank, to the chimney of the
boiler or into the open air direct. instead of through the condenser. The tem-
perature and pressure of the steam is so far reduced before it exhausts from the
low pressure cylinder of an engine such as described and shown that it can be
allowed to escape without noise into the atmosphere or, at any rate, only a com-
paratively small condenser is needed.
The driving platform is as shown, in front of the boiler, a seat 38 being pro-
vided for the driver and the controlling mechanism of the motive power, brake
and steering apparatus being arranged within easy reach of the driver and pre-
ferably in front of him. 39 is a hand wheel keyed upon a vertical shaft 40 the
lower end of which extends through the platform and carries a pinion 41 that
is geared to a toothed wheel 42 carried by a rotatable kingbolt 43, which also
has keyed to it a transverse plate or frame 44 formed at the ends with horn
plates 44" which guide the front axle 45 on which the front wheels 46 are
mounted. 47 is a bearing spring arranged between the axle and the plate 45.
The vehicle is provided with two brakes 48 and 49. The brake 48 is adapted
to grip a friction wheel 48" upon engine shaft 11 and is operated by means of a
hand lever 48b with which it is connected. The brake 49 is a double band
brake that is adapted to grip a friction pulley 49* on each of the axles 5, 5ª; it
is operated by a hand lever 49b that is connected to a transverse shaft 49° that
carries the lever arms to which the ends of the two brake bands are connected.
Figs. 10 and 11 are diagrammatic views indicating a modified arrangement in
which the vehicle is provided with only one driving wheel 6, the axle 5 of which
is journalled in suitable bearings fitted in horn plates arranged near the rear

page_text: end of the vehicle. The single driving-wheel is placed in the centre of the width
of the vehicle so that in turning on the road it forms the centre of motion and no
"Jack-in-the-box" is required, as is the case when there are two driving wheels
arranged at a distance apart from each other. The engine cranks 15 are fixed to
the axle of the driving wheel, preferably outside its bearings and on each side
of the driving wheel a steadying wheel 50 is arranged, said wheels 50 being
mounted on studs or axles carried by the frame of the vehicles. The bearing
springs of the driving wheel are much stiffer than those of the steadying wheels;
so that the greater portion of the weight of the rear part of the vehicle is borne
by the driving wheel and the adhesion necessary for traction thus obtained.
Instead of admitting steam direct from the boiler to the high pressure cylinder
throughout the whole of its piston stroke it is desirable for the sake of economy
to be able to work expansively when desired, for instance, when running light or
on a level road, and in order that the expansion valve provided for effecting. this
may be readily rendered inoperative at will and independently of the position
of the piston, I sometimes provide the steam inlet pipe 28 of the cylinder 13
with the valve arrangement illustrated in section in Fig. 12.
51 is a cylindrical chamber formed with a pair of ports 52, 53, the passage of
steam through which to the valve chest of the cylinder 13 is controlled by
valves 54 and 55 respectively. The valve 54 may be moved by hand so as to
open or close the port 52 by means of a lever arm 56 fixed to a spindle 57 that
extends to the exterior of the chamber where it is provided with a handle 57"
and is supported in a bearing 58; 58" is a locking screw for securing the valve 54
in any desired position. The valve 55 is an expansion or cut off valve and is
rocked to and fro over the port 53 by the engine through a lever arm 59 fixed to
a tubular spindle 60 that fits over the spindle 57 and extends to the exterior of
the chamber 51 through a stuffing box as shown; fixed to the spindle 60 is a
crank arm 61 to the pin of which is connected the rod of an eccentric (not shown)
that is driven by the engine and is so set as to cause the valve 55 to uncover
the port 53 during a given portion of each stroke of the piston and to close
it during the remainder of the stroke. As will be seen by opening the port 52
the expansion valve 55 is rendered inoperative, steam being allowed uninterrupted
access throughout the whole of the piston stroke to the valve chest through the
port 52. I may effect the same object by means of two piston valves arranged
in one cylinder, the one being operated by the engine and constituting an expan-
sion valve and the other controlling a port and capable of being operated by the
driver so as to allow steam to pass to the valve chest through the said port,
thereby rendering the expansion valve inoperative.
募
In place of the condenser illustrated in Figs. 8 and 9 I prefer to use a con-
denser such as is illustrated in sectional elevation in Fig. 13. This condenser
comprises a chamber 31b into which the exhaust from the engine is led through
a pipe 31 which is perforated preferably on its upper and lower sides; the
chamber 31 is connected by a series of tubes 31° to a collecting chamber 31'
from the lower part of which a pipe 32 leads to the boiler feed pump, whilst a
pipe 34 leads to the circulating pump which discharges into a cooling tank
whence water is led to a spraying pipe 62 which is adapted to be oscillated
through a connection between the engine and an arm 62* or caused to revolve
'by the reaction of the water flowing through it so that the spray trickles over all
the tubes 31° and its evaporation facilitates the condensation of the steam passing
through them. Beneath the tube 31° is arranged a trough or dish 63, which
may be covered by a perforated plate 63", adapted to catch water dripping from
the tubes, whence it is led through a drain pipe 63b, which may be fitted with
a non-return valve, to the collecting chamber 31. 64 is a cold water supply
pipe perforated along its underside; water admitted through this pipe serves as
an injection to assist condensation of the steam and also to make up the feed
water. 65 is an outlet pipe whereby uncondensed steam is allowed to escape to
the funnel or smoke box of the boiler so as to avoid pressure in the condenser.

page_text: As will be understood I do not confine myself to the precise constructions and
arrangements shown as various modifications may be introduced without depar-
ture from my invention.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is;.
-
1. A road vehicle, the driving wheel or wheels of which is or are driven by
means of a compound steam engine the cranks of which are of considerable
length and is so constructed and arranged that steam can be admitted to the high
pressure cylinder throughout practically the whole stroke of its piston, and the
low pressure cylinder throughout a considerable portion but that by the operation
of a valve or valves other than the distributing valves high pressure steam may
be admitted to both cylinders during practically the whole of their piston strokes,
substantially as described.
2. A road vehicle, the driving wheel or wheels of which is or are driven by
means of a compound oscillating steam engine having its cylinders arranged
one on each side of the framing or between the frames of the vehicle and its
pistons connected to long cranks carried by the engine shaft, which shaft is
geared to the driving wheel-axles through gear that permits said axles to travel
at different speeds, the arrangement being such that high pressure steam, can,
when desired, be admitted to both cylinders of the engine, substantially as
described and shown for the purpose specified.
3. For use in road vehicles propelled by means of a steam engine, condensers
wherein heat is transferred from the exhaust steam to the boiler feed water and
the condensation of the exhaust steam is accelerated by contact with surfaces
cooled partly by air and partly by water substantially as described with reference
to the drawings.
4. For use in road vehicles propelled by means of a steam engine, condensers
of the kind referred to in the preceding claim, comprising a cooling water reser-
voir, a steam and water chamber, open ended tubes extending from a lower water
collecting chamber to above the floor of the said steam and water chamber and
having perforations a little below their upper ends, constructed, arranged and
operating substantially as described, with reference to Figs. 8 and 9 of the
accompanying drawings.
5. My improved motor-propelled road vehicles constructed, arranged and oper-
ating substantially as hereinbefore described with reference to the drawings
annexed.