Improvements in Steam Engines.
Year: 1888

page_text: Date of Application, 7th Apr., 1888
Complete Specification Left, 7th Jan., 1889
Complete Specification Accepted, 23rd Feb., 1889
PROVISIONAL SPECIFICATION.
Improvements in Steam Engines.
I, SAMUEL SMITH WELCH, of 14 Emma Place, Stonehouse, Plymouth, in the
County of Devon, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to apparatus for actuating the valves of steam engines.
In place of fixing the eccentric to the main shaft I make it capable of sliding to
and fro preferably in a dove-tail groove in the face of a disc upon the shaft, the
eccentric being suitably slotted at the centre where the shaft passes through it ; in
order to move the eccentric to and fro across the shaft, so as to vary the cut off or to
reverse the engine, I provide a bell crank lever pivotted to the disc, one arm of which
carries a stud which enters a slot in the eccentric or is otherwise connected to it the
other being pivotted to a sleeve turning with the shaft but capable of sliding to and
fro upon it. Motion is given to the sleeve by a hand lever or by the governor.
In order to work the valves of a three cylinder engine from a single eccentric I
adopt the following arrangement :-One of the valves is worked direct in the usual
manner by a rod fixed to the eccentric strap. The other two valves are worked by
rods pivotted to arms fixed upon two rocking shafts one working within the other
which is hollow. Motion is given to the hollow shaft through a second arm fixed. to
it, to whose end is pivotted a rod fixed to the eccentric strap. Motion is given to the
other rocking shaft by means of a rod pivotted to the end of an arm fixed to it the
other end of the rod being pivotted to the rod of the first mentioned valve.

page_text: I, SAMUEL SMITH WELCH, of 14 Emma Place, Stonehouse, Plymouth, in the
County of Devon, 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 relates to apparatus for actuating the valves of steam engines.
In place of fixing the eccentric to the main shaft 1 make it capable of sliding to
and fro preferably in a dove-tail groove in the face of a disc upon the shaft the
eccentric being suitably slotted at the centre where the shaft passes through it; in
order to move the eccentric to and fro across the shaft, so as to vary the cut off or to
reverse the engine, I provide a bell crank lever pivotted to the disc, one arm of which
carries a stud which enters a slot in the eccentric or is otherwise connected to it the
other being pivotted to a sleeve turning with the shaft but capable of sliding to and
fro upón it. Motion is given to the sleeve by a hand lever or by the governor.
In order to work the valves of a three cylinder engine from a single eccentric I
adopt the following arrangement. One of the valves is worked direct in the usual
manner by a rod fixed to the eccentric strap. The other two valves are worked by
rods pivotted to arms fixed upon two rocking shafts one working within the other
which is hollow. Motion is given to the hollow shaft through a second arm fixed to
it, to whose end is pivotted a rod fixed to the eccentric strap. Motion is similarly
given to the other rocking shaft by means of a rod pivotted to the end of an arm
fixed to it.
In order that my said invention may be fully understood and readily carried into
effect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figures 1 and 2 shew the eccentric and parts in immediate connected therewith.
Figures 3 and 4 show the valve gear.
a is the crank shaft and 6 is the eccentric, the shaft passes freely through it by a
slotted hole. c is a disc fast upon the shaft-The eccentric b can slide upon the disc c
with which it is connected by a dovetail projection upon the eccentric entering a
corresponding recess which extends transversely across the face of the disc..
d is a sleeve which slides upon the shaft with a groove and feather it has an
arm d. ee are two bent levers mounted on the disc c so as to be able to rock about
centres at e¹ e¹One limb of each lever e is jointed to the arm d¹ of the sleeve-The
other arm passes freely through an opening in the disc and terminates in a circular
stud which is received into a corresponding hole in the eccentric-Or the eccentric b
and levers e are otherwise connected so that the levers when they move about their
centres e¹ impart a movement to the eccentric in a plane perpendicular to the shaft.
The sleeve is controlled by any suitable gear for varying the expansion or for reversing
the engine.

page_text: Figures 3 and 4 show a method of actuating the three slide valves of a three
crank, three cylinder engine by means of one eccentric only and which is also
movable for the purpose of reversing the engines and for altering the cut off.
The eccentric A is placed on the crank shaft B and works one slide valve direct
through eccentric rod C.-Two eccentric rods D. d are worked off the eccentric at
angle of 60° corresponding with the angles of the cranks. The middle slide valve is
worked by the eccentric rod D and the short lever Ę giving motion to the hollow
shaft Fon which is fixed the short lever e. The remaining slide valve is worked by
the eccentric rod d, which transfers the motion by means of the short levers Gg and
the rod H to the shaft J on which is keyed the short lever I. The short levers e
and I being connected to the slide valves of the engine. By the means above described
and by placing one slide valve directly over the eccentric, both of the remaining
slide valves can be placed and worked side by side at the back or front of the
engine.
KK are the columns or cylinder supports and L L are brackets or bearings in
which works the hollow shaft F and the internal shaft J.
In place of the arrangement shown the rod H may be replaced by a rod jointed to
the eccentric rod O and imparting movement to the shaft J as shown, the rod d and
lever G being dispensed with.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The mechanism substantially as described for shifting the eccentric upon the
engine shaft consisting of the disc c carrying the eccentric; the lever or levers e e
also mounted on the disc and the sleeve a sliding upon the shaft and connected with
the levers e.
2. The eccentric with parts connected therewith substantially as described in
respect to Figures 1 and 2 of the annexed drawings.
3. The arrangement of valve gear substantially as described for a three cylinder
engine the cylinders being arranged vertically and in a row side by side, with one
eccentric operating all the valves; the valve of one of the end cylinders being on
the centre line of the row and connected directly with the eccentric by a rod; and
the other valves being at the side of the row of cylinders and receiving motion
from the eccentric through two concentric shafts as set forth.
4. The arrangement of valve gear substantially as described in respect to Figures 3
and 4 of the annexed drawings.
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