CERTAIN IMPROVEMENTS IN LOCOMOTIVE ENGINES AND CARRIAGES
Year: 1841

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
BUNNETT, of Deptford, in the County of Kent, Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Third day of February, in the fourth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said Joseph
Bunnett, Her especial licence, full power, sole privilege and authority, that I,
the said Joseph Bunnett, my exors, admors, and assigns, and such others as I,
the said Joseph Bunnett, my exors, admors, or assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term of years therein expressed, should and lawfully might make, use, exercise,
and vend, within that part of Her Majesty's United Kingdom of Great Britain
and Ireland called England, Her Dominion of Wales, Town of Berwick-upon-
Tweed, the Islands of Guernsey, Jersey, Alderney, Sark, and Man, and also
in all Her Majesty's Colonies and Plantations abroad, my Invention of
"CERTAIN IMPROVEMENTS IN LOCOMOTIVE ENGINES AND CARRIAGES;" in which said
Letters Patent is contained a proviso that I, the said Joseph Bunnett, shall
cause a particular description of the nature of my said Invention, and the
manner in which the same is to be performed, to be inrolled in Her Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said in part recited Letters Patent, as in and by the same,
reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Joseph Bunnett, do hereby declare that the nature of my said improvements,

page_text: and the manner in which the same are to be performed, are clearly ascertained
and set forth in the following description thereof, reference being had to the
Drawings hereunto annexed, that is to say :-
My said invented improvements consist,―
Firstly, of an apparatus for regulating the admission of steam to the
working cylinders of locomotive engines, which requires, in order to onward
motion, that the engine driver should have his hand constantly applied to it,
and which, the moment his hand is removed from it, closes of itself the
openings which regulate the admission of steam into the cylinders, and
thereby soon brings the engine and carriages which may be attached to it
to a standstill.
Secondly, of certain improved breaks for arresting the progress of loco-
motive engines, and railway and other carriages.
And, thirdly, of an improved axle guard for railway carriages, which allows
a compensating movement of the axle when the wheels are traversing curves
or irregularities of a line of rails.
The details of the first part of the said improvements are shewn in Figure 1
of the Drawings hereunto annexed, which represents the end of a locomotive
engine of the ordinary construction. A is the usual handle of the regulator,
through which steam is admitted from the boiler to the working cylinders of
the engine. B is a second or supplementary handle, upon the spindle or axis
of which is placed a pully c. D is a strong curved spring, firmly attached by
one end to the back plate of the firebox, while the other end passes round
and embraces a stud or pin on the handle of the regulator A. The constant
tendency of this spring is to draw the regulator into such a position. that its
apertures are closed and the steam shut off from the cylinders. Attached to
the handle A there is a chain E, the other end of which is fastened to the
pulley c. When it is desired to turn on the steam and start the engine, the
driver takes hold of the handle B, and turns it round in the usual direction
until a sufficient quantity of steam is admitted to the engine to enable it to
attain its required speed. By altering the position of this handle the engine
driver exercises the usual controul over the speed of the engine, increasing it
or diminishing it, according to circumstances; but should he from carelessness,
from drowsiness, from illness, or from any other cause, relinquish his hold of
the handle B, the spring D instantly closes the regulator, shuts off the steam,
and thereby brings the engine to a stop.
The second branch of my said improvements includes five different sorts of
breaks to be applied to the wheels of locomotive engines, and railway and
other carriages, for the purpose of stopping the same. The first which I shall

page_text: describe is shewn partly in Figure 1 and partly in Figure 2, which is a side
elevation of a locomotive engine. F is a vertical shaft or spindle, working in
suitable bearings, having at its upper end a handle, and at its lower extremity
a worm or endless screw. This endless screw takes into a worm wheel f
keyed upon a horizontal shaft or axle G, laying across the back part of the
engine. This shaft also carries two pinions (shewn more clearly in Figure 1),
which work into two racks on the ends of the segmental levers H, II. These
racked segments are supported near their further extremity by two pius
placed between and attached to the firebox and the outer frame of the engine..
I, I, are two curved steel plates, fastened to the framing of the engine by
pin joints at K, K. To the under side of these plates are bolted two boxes or
segments L, L, filled with wood placed endways of the grain, or, instead of the
boxes, cushions of leather, or any other suitable elastic or partially elastic
substance, may be used. These plates and segments are connected with the
racked levers H, H, by pin joints at M. When the racked end of the levers
H, H, are depressed, the steel plates I, I, and the breaks L, L, are supported
above and clear of the wheels, but on turning the vertical shaft F, motion is
given to the worm wheel and pinions on the horizontal shaft G, which, raising
the racks and levers II, H, depresses the steel plates I, I, and brings the
breaks L, L, in forcible contact with the peripheries of the wheels of the
engine. The breaks are shewn in the Drawing as acting upon the driving
and trailing wheels, but they may be applied to the driving wheels, to the
trailing wheels, or to the leading wheels, or to all or any of them combined.
A second description of break is shewn in Figures 3 and 4, Figure 3 being
an elevation, and Figure 4 a plan thereof. N is a vertical shaft placed at the
end of the carriage, having at its upper end a handle, and at bottom an
endless screw or worm. O is a horizontal shaft, lying in a central position
lengthways of the carriage, having at its outer end a worm wheel, which takes
into the endless screw on the bottom of the vertical shaft N, and at the other
end a small bevil wheel, working a corresponding wheel on the top of the
short vertical shaft P. On the lower part of this shaft P there is a pinion
lying between and working in the two rack bars Q, Q. The outside of these
guides to keep thei
racks work against anti-friction rollers, which serve as
in their proper places, and in contact with the pinion. The bars Q, Q, aro
prolonged towards the end of the carriage, and terminate in arms R, R, which
lay across the carriage, extending from side to side, and working upon two
guide bars r, r, attached to the ordinary stay of the carriage. To each end
of the arms R, R, a strong bow S is attached, opposite to and parallel with
the plane of the wheels. Between the two extremities of each of these bows

page_text: a strong belt, of any suitable fabric, or leather belt T, T, is stretched, with a
pall and ratchet, a screw and nut, or any other suitable provision for keeping
it in a state of tension. The screw and nut is shewn as applied to this
purpose in Figure 9. When it is desired to apply the breaks the guard turns
round the handle of the shaft N, which, by means of the endless screw, worm
wheel, and bevil wheels, gives motion to the pinion on the shaft P, which
turning causes the racks to traverse outwards, moving the arms R, R, towards
the extremity of the carriage, and simultaneously forcing all the belts T, T,
against the peripheries of the wheels, and thus arresting their motion. The
belts or straps yield slightly to the pressure, and readily adapt themselves to
the curves of the wheels. Although these breaks are only shewn in the
Drawings as applied to act on one side of four wheels, they are equally
applicable to act on one or both sides of four, six, or any other number of
wheels. By continuing the horizontal shaft O to the other end of the carriage,
the breaks may be made to act from either end, an arrangement which will
afford great convenience on lines of railways not provided with turntables.
A third description of break is shewn in Figures 5 and 6, Figure 5 being a
side elevation, and Figure 6 a plan thereof. A' is a cross bar, which is
furnished with collars at each end, through which the buffer rods are passed,
and is attached to a central rod B¹, which passes along in an inclined position,
beneath the carriage, in a line directed to the centres of the wheel axles. At
its further extremity the rod is forked, and embraces an elliptical or other
spring C¹, which lies horizontally, and is attached to a cross bar D¹. Instead
of the usual straight rod or stay between the wheels, a curved stay is intro-
duced, the ends of which correspond with the direction of the plane of motion
of the breaks, and upon which the ends of the cross bars D¹ work. At the
two ends of this cross bar, directly opposite to the peripheries of the wheels,
two segment boxes E¹ are bolted, which are fitted with wooden segments, or
other elastic or partially elastic substances, or the cross bar is fitted with bows
and leather straps or belts, as made use of in the second form of break, before
described. A similar arrangement of cross bars, springs, breaks, &c., as before
described, proceeds from the other end of the carriage to the opposite wheels
thereof. In the event of a carriage thus fitted forming part of a train, and
the steam being shut off from the engine, and the breaks applied, or its onward
progress in any other manner arrested, the engine would present an obstacle
to the advance of the carriages following it, which being carried forward by
their momentum, their front buffers would come in contact with the opposing
obstacle, and, being driven inward, would press the breaks upon the kind
wheels with a power equivalent to the momentum of the moving mass, while

page_text: the following carriages of the train, pressing upon the hinder buffers of the
foremost carriage, would force its breaks on to the forewheels, their own being
simultaneously applied to their hinder wheels by the force of impact. By this
means the whole of the carriages in the train will be gradually but effectually
retarded, and eventually stopped. In the event of a collision also, the force
of the concussion will be distributed among all the several springs of the
buffers and breaks throughout the train, thereby greatly reducing the risk
of danger. The central rods B' are provided with screws & nuts for accurately
adjusting their length, so as to act with a determinate force upon the breaks
at any required point of retrocession of the buffer rod, an arrangement which
may be employed with advantage to regulate the speed of the train down
inclined planes. As soon as the momentum of the train has been overcome,
and it has been brought to a state of rest, the reaction of the ordinary buffer
springs removes the breaks from off the wheels.
A fourth description of break is shewn in Figures 7 and 8, Figure 7 being
a side clevation of a portion of a carriage, and Figure 8 a plan of the same.
The distinguishing peculiarity of this break is, that it is applied to the outside
or in front of the nearest wheels, instead of to the inside of the farthest
wheels. A', as before, is the cross bar attached by a forked clip to the spring
C', working between guides formed on the bar D¹. A guide is formed for the
two ends of this cross bar by the two rods forming the ordinary axle guard
stay. This break may be also used as a manual break by employing an appa-
ratus similar to that shewn in Figures 3 and 4, only substituting a pulley and
chains for the pinion and racks, as shewn.
A fifth description of break is shewn, applied to Figures 3 and 4, in
which a connecting rod F 1 is attached to the inside of the buffer by a collar;
the other end of the rod is attached by a pin joint to the bell-crank lever G¹.
To the other arm of the bell crank is attached a strong leather strap or belt
H. This strap or belt passes over the wheel without touching it, and is
affixed to and kept in a state of tension by a strong bent spring I¹. When
any resistance is offered to the buffers they are forced in, and acting upon the
bell-crank lever, which draws the strap or belt down upon the periphery of the
wheel with a power equivalent to the strength of the spring, and to the force
acting upon the buffers. A break of this sort should be applied at each end of
the carriage, and such breaks may be made to act upon all the wheels, whether
four or more are employed. In Figures 5 and 6, I have shewn an arrange-
ment by which any of the breaks before described may be used as manual
breaks, independently of their ordinary self-acting powers. For this purpose
a vertical shaft is placed at one end of the carriage furnished with a handle

page_text: at top, and having an endless screw at its lower extremity, which works into
a worm wheel on the horizontal shaft K. The shaft K¹ extends to the
centre of the framing beneath the carriage, where. it carries a small drum or
pulley L. To each of the cross bars D¹ two rods M₁ are attached by pin
joints, the ends of each pair of rods being connected together by pins at N¹.
From each of the joints Na chain proceeds to the drum or pulley L³, to
which they are attached on opposite sides. When it is required to apply
these breaks by hand the handle is turned, which, giving motion by means of
the worm wheel: to the horizontal shaft K¹ and drum L', winds up the chains
upon the latter, and causes the joints of the levers N₁ to approach each other,
whereby the bars D¹ are made to recede from the centre of the carriage, and
the breaks are forced upon the wheels, independently of their self-acting
motion. When the handle is reversed and the pressure withdrawn, the breaks
are returned to their places by springs placed inside the joints N¹, or in any
other convenient position. These Figures also shew the mode of using the
springs C as traction springs. 01, 0¹, are two traction rods attached to the
end of the spring C¹; their other ends meeting are attached to a hook P¹
(shewn in Figure 5), to which the connecting links of the tender or other
carriages is fastened. The rod B is furnished with a collar which abuts
against a plate on the inside of the cross rails of the carriage frame when the
traction rods O¹ are pulling upon the springs C³.
The third branch of my said improvements, including the improved axle
guard, is exemplified in Figure 5, which is a side elevation of the framing of
a railway carriage. Q¹, Q¹, are the two axle guides, of any approved form,
between which the axle boxes slide up and down. Instead of these axle
boxes fitting tightly within the guides as usual, a little play is allowed them.
Two strong flat steel springs R', R¹, are hung upon bolts between the plates or
stays forming the axle guides, their lower ends impinging against the axle
boxes, and tending to maintain them in a central position, but yielding to the
unequal pressure of the axle in either direction when traversing curves or any
irregularities in the line of rails, and resuming their central position as soon as
the cause of the deviation is passed. Two set screws S¹, S¹, pass through
bosses placed between the plates of the axle guides, by which the pressure of
the spring against the axle box is adjusted and regulated at pleasure.
And having now described the nature of my said invented improvements,
and the manner in which the same are to be performed, I declare that what
I claim is,-
First, the application to locomotive engines of a spring for the purpose of
keeping the steam-way or passage through the regulator constantly closed,

page_text: except when held open by the engine driver applying his hand directly to the
handle of the said regulator, or to the supplementary handle acting through a
chain and pulley, as before described.
Secondly, I claim the general combination of mechanical contrivances
peculiar to and distinctive of each of the five sorts of breaks herein-before
described, and whether the same is applied to locomotive engines or to railway
carriages, or to carriages of any other description; and,
Thirdly, I claim the improved construction of axle guards, whereby a com-
pensating motion is brought into play when railway carriages are working
round curves or over irregularities of lines of rails, as exemplified and
described in Figure 5 of the Drawings hereunto annexed.
And such my said Invention being, to the best of my knowledge and belief,
entirely new, and never before used within that part of Her said Majesty's
United Kingdom of Great Britain and Ireland called England, Her Dominion
of Wales, Town of Berwick-upon-Tweed, the Islands of Guernsey, Jersey,
Alderney, Sark, and Man, or in any of Her said Colonies and Plantations
abroad, I do hereby declare this to be my Specification of the same, and that
I do verily believe this my said Specification doth comply fully and in all
respects, without reserve or disguise, with the proviso in the said herein-before
in part recited Letters Patent contained; wherefore I hereby claim to maintain
exclusive right and privilege to my said Invention.
In witness whereof, I have hereunto set my hand and seal, this Third
day of August, in the year of our Lord One thousand eight hundred
Inrolled the Third day of August, in the year of our Lord One thousand
eight hundred and forty-one.