IMPROVEMENTS IN LOCOMOTIVE AND OTHER ENGINES
Year: 1879

page_text: LETTERS PATENT to Henry F. Shaw, of Boston, Massachusetts, United States
of America, for the Invention of "IMPROVEMENTS IN LOCOMOTIVE AND OTHER
ENGINES"
Sealed the 27th February 1880, and dated the 11th November 1879.
COMPLETE SPECIFICATION filed by the said Henry F. Shaw at the Office
of the Commissioners of Patents on the 11th November 1879.
"IM-
HENRY F. SHAW, of Boston, Massachusetts, United States of America.
PROVEMENTS IN LOCOMOTIVE AND OTHER ENGINES."
My Invention consists, first, in the employment of two steam cylinders, two
pistons, and two connecting rods for the driving wheels on each side of a loco-
motive engine, and also in the use of two parallel rods for each pair of driving
wheels on each side of a locomotive engine, the connecting and parallel rods,
cranks, and crank pins, being so arranged oppositely with reference to the driving
wheels, that the weight of the said connecting and parallel rods, cranks, and crank
pins will be counterbalanced, and the driving wheels will be balanced when in
motion as well as when at rest, and the motive force exerted on the driving wheels
being exerted on opposite sides of each axle will be counterbalanced with reference
to the said axle, or, in other words, be converted more directly and completely into
torsion or force to produce rotation.
It has been the custom to use one connecting rod on each side of a locomotive,
and one parallel rod for a pair of wheels on each side of a locomotive, and the
weight of the connecting rod, or connecting and parallel rods together with crank
and crank pin, has been balanced in each driving wheel by a counterbalancing
weight fixed opposite to the same in the wheel. While by this method the
wheels may be balanced when stationary, they are not in balance when in motion
since the weight on each wheel of the connecting rod, or connecting and parallel
rods, does not remain in the same condition or relation to the wheel that the fixed
weight does, hence, the weights intended to counterbalance each other being under
different conditions with reference to the wheel, must exert upon the wheel
different influences, that is to say, they will not be truly counterbalance weights,
and the wheel therefore will not be balanced. The more rapid the revolution of.

page_text: the wheel the greater will be the difference in the force of the two weights,
namely, the weight of the connecting rod or of the connecting and parallel rods and
the opposite fixed weight, and the more out of balance will the wheel be by
reason of the increased centrifugal force accumulated in and exerted by the said
weights. To a still greater extent is the balance of the wheel, which may be in
balance when at rest, destroyed when the fixed weight therein is placed at a
different (generally at a greater) distance from the centre than the weight which
changes its condition with reference to the wheel, namely, the weight of the
connecting rod or connecting and parallel rods; and when the fixed weight is so
placed that portion of it which is intended as a balance to the crank and crank
pin exerts a different influence on the wheel from the weight of the said crank and
crank pin, according as the centrifugal force is developed.
The general effects believed to be produced when a fixed weight is used in each
wheel for balancing are to cause the wheels to slip on the rails to cause a pounding
action of the wheels on the rails, and hence an unnecessary wear in both wheels
and rails, and to cause both side and lifting impulses to be given to the whole
locomotive, whereby it does not ride so smoothly, and cannot run at the speed
that would otherwise be practicable.
When one cylinder and piston are used for the wheel or wheels on one side of a
locomotive, the driving force being exerted on each wheel only on one side of the
centre of the wheel, it is believed that much of the pressure is brought to bear on
the bearings of the wheel or wheels, which is not utilized to rotate the wheel or
wheels or impel the locomotive, but is wasted or exhausted by friction, and that
unequal and ever varying impulses are given to the locomotive carriage.
By my Invention comprising as it does, first, as aforesaid, the use of two cylinders,
two pistons in connection with two connecting rods for the driving wheel or wheels,
and two parallel rods for each pair of driving wheels on each side of a locomotive
engine, the driving wheels may be perfectly balanced while in motion, and at any
speed, as well as at rest. The weight on a wheel on one side of its centre of one
connecting or parallel rod, or of a connecting and a parallel rod, is counterbalanced
by a connecting or parallel rod, or counterbalanced by the weight of a connecting
and a parallel rod on the other side of the centre. This result I accomplish by
employing a so called double crank on the outside of each driving wheel, so that
there are two crank pins at equal distances from the centre of the wheel, and at
opposite sides of said centre, arranged and connected with the connecting and
parallel rods, as more fully hereinafter described.
By the use of two cylinders the pressure exerted is caused to act on a wheel in
equal proportions on opposite sides of the centre, the said cylinders being arranged
and connected, as hereinafter more fully described, so that such pressure results in
a direct torsion force, and the bearings are relieved of any more pressure and
friction than naturally results from the weight of the locomotive, or appertain to
its propulsion.
My Invention also relates to a valve used in connection with two cylinders
having pistons which, when working, move the one in opposite direction to the
other; and it consists in a valve chest used in connection with two cylinders as
aforesaid, and provided with ports leading therefrom, one to each end of each
cylinder, and with a single slide valve having supply and exhaust passages, the
supply and exhaust passages in the valve being in such relation to the ports
leading to the cylinders that the said supply or exhaust passages shall enter upon
the said ports on the same side for one cylinder that they do for the other cylinder.
This arrangement is such that while using one valve slide for the two cylinders
the "lap" and "lead", so called, may be made alike for each cylinder, as will be
more clearly seen by the description hereinafter given. This part of my Invention
is adapted to other engines, stationary as well as locomotive engines.
"
My Invention also consists in the use on each side of a locomotive of a rail,
which I style a guard rail," outside of the driving wheels in connection with
and as a means of support for the outer ends of the double. cranks. afore named.

page_text: My Invention also consists in pieces which assist in connecting the guard rail
with the main frame work of the locomotive, and not only assist in supporting
said guard rail, but are so located and formed over the connecting and parallel rods
as to serve as guards against further accident or damage from said connecting or
parallel rod should one of the latter break. These pieces, from their office, I style
guards."
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Having thus set forth in general terms in what my Invention consists I shall
now proceed to so more fully explain with the aid of the accompanying Drawing,
that anyone skilled in the business of locomotive building may construct engines
according to my Invention.
In the accompanying Drawing,-
Figure 1 is a side view of so much of a locomotive engine embodying my
Invention as serves for illustration of the same.
Figure 2 is a front view of the engine, shewn in Figure 1.
Figure 3 is a plan of the framework of the locomotive, the boiler and other parts
being omitted for the sake of clearness, and shews especially the position and
relation to each other of the cylinders, driving wheels, connecting and parallel rods.
Figure 4 is a section of two adjacent cylinders, valve chest and valve, taken on
the line 1, 1, in Figure 3.
Figure 5 is a plan of two adjacent cylinders, valve chest and valve, the cap of
the valve chest having been removed.
Figure 6 is a view of the parts shewn in Figure 5, with the exception of the
valve, and
Figure 7 is a plan of the underside of the said valve.
Like letters indicate the same parts throughout the Drawing.
Figures 4, 5, 6, 7 are drawn on a larger scale than Figures 1, 2, and 3.
The locomotive represented has two driving wheels on a side, two forward
wheels A, A, and two to the rear of these B, B. The axles C, C, of the driving
wheels have bearings supported by the frame pieces D, D. On each side of the
locomotive are two steam cylinders E, E; each cylinder has a piston connected
To each of the
with one of the piston rods F to operate in the usual manner.
piston rods F or to a cross-head connected therewith at one end is pivoted a
connecting rod G in the usual way. Each driving wheel has fixed thereto upon
the outside a double crank H, that is a crank having two crank pins or bearings
a, b; these pins or bearings a, b, being upon opposite sides of and at equal distances
from the centre of the wheel, and so formed and located that the rods pivoted
thereon may pass each other, substantially as shewn.
There are two parallel rods I, I, for the pair of wheels on each side of the loco-
motive, which are pivoted at their ends on the two pins of each of the double
cranks, as shewn.
It will be observed that I have shewn each of the connecting rods G pivoted at c
to one of the parallel rods I. This method of connection I prefer, and is equivalent
in general effect to having each connecting rod pivoted and bearing directly on a
pin of the double crank at the side of the parallel rod, the latter method may be
adopted when desirable.
Along each side of the locomotive extends a rail J, which I call a "guard rail."
It is connected at each end with the main frame work, or one of the frame pieces D.
It is further supported and stayed by the bars or stays K, K, as many as are
required, and in this case located as shewn. These bars or stays K also serve the
purpose of protection, namely, by guarding against the flying upward of the con-
necting or parallel rods, or other adjacent parts, should they break or become
disengaged from their bearings, and hence I call them "guards."
Each of the double cranks H extends to form a pin or shaft d concentric with
the centre of the wheel and its axle, and having a bearing in a box e fitted to be
held in place in the guard rail J there being between the upper end of the box e
and the rail J a spring or elastic connection f. This manner of giving further
support to the double crank by means of a pin or shaft d supported by the guard

page_text: rail I prefer, since the crank will be steadied and be secured against springing, and
hence may be made lighter than would otherwise be practicable. Each double
crank may however be made sufficiently strong and be joined to the driving wheel
or its axle, rigidly enough not to require the outside support obtained by the pin
or axle d, which may be considered as an extension of the main axle C. Moreover
in some locomotives it may be desirable to dispense with the guard rails J and the
guards K, though the construction, substantially as shown, I deem the desirable
one in most cases.
Each pair of cylinders E, E, has connected therewith, substantially as shown,
one valve chest L which receives the supply of steam in the ordinary manner. In
each valve chest L is a slide valve M on its seat g being moved by means of a
valve stem h in the ordinary manner. Four steam ports i, i, and j, j, lead from
the valve chest to the ends of the cylinders, there being one of the ports i, i, for
the forward end of a cylinder, and one of the ports i, j, for the rear end of a
cylinder.
pass
In each valve M there are four steam supply passages k, k, and 2, 1, which
through the valve, substantially as shewn, the passages k, k, for one cylinder being
nearer together than the passages 1, 1, for the other cylinder; they are all located
so that one of the passages k, k, will pass on to one of the ports i, i, as one of the
passages, 1, passes off from the other one of the ports i, i, or vice versa, and so
with the ports j, j. There are four exhaust passages in each valve arranged
similarly to the supply passages, that is to say, the two passages m, m, for one
cylinder, one nearer together than the two n, n, for the other cylinder. The four
exhaust passages open into one common exhaust passage o in the valve, which
passage opens into a common exhaust passage p beneath the chamber of the
valve chest leading to a common exhaust pipe q.
The relative position of the steam ports from the valve chest to the cylinders
and the steam passages in the valve is such as will be readily understood from the
Drawing, namely, that the steam passages in the valve enter upon and leave the
steam ports to the cylinder upon the same side for one cylinder that they do for
the other cylinder. The general effect of my arrangement of the said passages and
ports is that by the use of one slide-valve for two cylinders, moved as an ordinary
slide-valve for one cylinder, the steam is admitted into one end of one cylinder
and into the opposite end of the other cylinder while the steam is exhausted from
the other end of the first cylinder and the end opposite thereto of the second
cylinder, the two pistons being thus caused to move in opposite directions as
required, and the "lap" and "lead" (so called) of the valve for both cylinders
being the same.
My improved construction of valves is not confined to locomotive engines, but is
adapted to other engines which are operated by steam, water, or compressed air,
and in which there are two cylinders situated with reference to each other sub-
stantially as shewn, and having pistons to ply in opposite directions.
Having thus fully described my said Invention and the manner of performing
the same, I wish it understood that I do not limit myself to the precise details of
construction and arrangement above described, as the locomotive or other engine
may be somewhat modified to adapt it to the particular work to be performed
thereby, and the same may embody one or any number of the parts of my Inven-
tion as above described, and I claim,―
First. The employment of two cylinders and two connecting rods for the driving
wheels on each side, and two parallel rods for each pair of driving wheels on the
same side of a locomotive engine, substantially as and for the purpose hereinbefore
set forth.
Second. A slide valve used in connection with two cylinders whose pistons work
or ply in opposite directions, and which valve has supply and exhaust passages in
such relation to the ports leading to the cylinders that the said passages enter upon
the said ports on the same side for one cylinder, as they do for the other cylinder,
substantially as hereinbefore set forth.

page_text: Third. The employment of a guard rail outside of the driving wheels as an
additional support for the double crank or cranks, substantially as hereinbefore
set forth.
Fourth. The bars or stays for connecting the said guard rail with the main
frame work, so located as to serve as guards, substantially as hereinbefore set
forth.
HENRY F. SHAW. (L.S.)