Improvements in the Valve Gear of Locomotive Engines.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Valve Gear of Locomotive Engines.
I FRANCIS WILLIAM WEBB of Chester Place Crewe in the County of Chester
Mechanical Engineer do hereby declare the nature of this invention to be as
follows:-
My improvements consist in arranging the cranks of a four-cylinder locomotive
engine so that two sets of valve gear only will be required to drive the four valves
necessary to operate the pistons in the four cylinders. I arrange my crank axle &
crank pins in such positions in the driving wheels that the pistons in the two cylinders
on one side of the engine are at the opposite ends or thereabouts of their respective
cylinders at the same time. One of the valves of one of the cylinders is operated in
any of the usual ways by eccentrics & links or any of the suitable radial gears & the
other is worked through a double ended lever-one end being attached to the valve
rod or spindle of the valve so operated & the other end to the valve spindle of the
other valve. By this means the valves are worked in the proper direction for their
respective cylinders & pistous & if the double ended lever has the fulcrum in the
centre each valve will have the same range or stroke with every position of the
expansion gear. In the case of a Compound engine with one high pressure & one low
pressure cylinder on either side I arrange the fulcrum of the double ended lever so
that it can be moved nearer one end or other of the lever so that the stroke of one
valve in one cylinder can be made to vary with the other. The valves in the other
pair of cylinders are actuated in the same way.
Dated this 10th day of Dacomber 1806
I, FRANCIS WILLIAM WEBB of Chester Place, Crewe, in the County of Chester,
Mechanical 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 :-
My improvement consists in arranging the cranks of a 4-cylinder locomotive
engine so that two sets of valve gear only will be required to work the four valves
necessary to operate the pistons in the four cylinders. I arrange my crank axle &
crank pins in such positions in the driving wheels that the pistons in the two cylinders
on one side of the engine are at the opposite ends or thereabouts of their respective
cylinders at the same time. One of the valves of one of the cylinders is operated in
any of the usual ways-by eccentrics & links or any of the suitable radial gears, & the ▾

page_text: other valve is worked through a double ended lever, one end of which is attached to
the valve rod or spindle of the valve so operated & the other end of the lever is
attached to the valve spindle of the valve which receives its motion from the eccentric
or oth er gear. By this means the valves are worked in the proper direction for their
respective cylinders & pistons & if the double ended lever has its fulcrum in the
centre of its length, each valve to which it is attached will have the same range &
stroke with every position of the expansion gear. In the case of a Compound engine
with one high & one low pressure cylinder on each side of the engine, I arrange the
fulcrum of the double ended lever so that it can be inoyed nearer one end or other of
the lever so that the stroke of the valve in one cylinder can be made to vary with the
stroke of the valve in the other cylinder. The valves in the other pair of cylinders on
the engine are situated & worked in the same way.
The accompanying drawings illustrate the manner in which my invention is or may
be carried out, the same letters of reference indicating corresponding parts in all
the figs.
Fig. 1 is a section through the steam chest of a locomotive cylinder with the valve
spindle & valves in position. On one end of the spindle the ordinary crosshead D, to
which the valve rod is coupled in the usual way, is shown, & on the opposite end of
the spindle the crosshead E is shown, which couples to the double ended lever L for
the purpose of working the valve in the adjacent cylinder.
Fig. 2 is a sectional plan taken through the steam chests of two adjacent cylinders
showing the method of coupling & working the valves by my double ended lever
arrangement.
Fig. 3 shows the double ended lever L arranged with a slot in the centre to allow
the position of the fulcrum being altered in order that the stroke of the valves may
be varied as desired.
A & B (Figs. 1 & 2) are the valve chests of two adjacent cylinders & a, a, b, b
are "the valves which work in the same. C & C are the valve spindles for the
two cylinders. D is the ordinary crosshead to which the valve rod from the
eccentrics & links or other gear used, is coupled in the usual way. E & E¹
are the crossheads fixed on the ends of the valve spindles C & C & to these
crossheads is coupled the double ended lever L. Each of these crossheads has a
metal bush e & e¹ which is loose in the crosshead & free to turn so as to
accommodate itself to the motion of the double ended lever. F is the fulcrum
on which the double ended lever turns. In Fig. 3, G is a sliding block which
carries the fulerun for the lever 1.. This block may be moved into any desired
position in the slot g by means of a screw or any other suitable arrangement, &
by this incans the stroke of the valve worked by the lever may be varied as required.
Although in the accompanying drawings I show my double ended lever as attached
to the front end of the valve spindles, I do not confine myself to placing it in
that position, as, in some cases it may be preferable to fix it at the opposite end
of the spindles to that shown i.e. to the same end of the valve spindle to which
the valve rod from the eccentrics or other motion is attached.
Having now particularly described & ascertained the nature of my said inven-
tion & in what manner the same is to be performed, I declare that what I
claim is
The method of working the valves of two cylinders of a 4-cylinder locomotive
engine with one set of eccentrics & links or other suitable expansion &
reversing gear substantially as described & shown in the drawings.
Dated this 9th day of September 1897.