Improvements in Valve Gear of Engines Worked by Steam or Compressed Air or other Gases.
Year: 1889

page_text: Date of Application, 23rd May, 1889
Complete Specification Left, 24th Feb., 1890-Accepted, 29th Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in Valve Gear of Engines Worked by Steam or
Compressed Air or other Gases.
SYLVANUS EDDINGTON and JOHN EVAN STEEVENSON both of Chelmsford in the
County of Essex, Engineers, do hereby declare the nature of this invention to be as
follows:-
Our invention has for its object a simpler and more efficient method of actuating
the valves of engines worked by steam or compressed air or other gases and the
automatic regulation of the same and reversing the motion of the engine.
This is effected in the following manner :
There are two valves at each end of the cylinder or cylinders one for admission
and the other for exhaust these are operated by cams. (or other device) working on
and revolving with the crank shaft or a shaft driven from the crank shaft by gearing
or other mechanism. The governors are mounted on the same shaft and attached to
the cams (or other device) as they. expand they move the cams (or other device) so
that a different part comes into contact with the levers working the valves. When
the engine is required to reverse two sets of cams (or other device) are coupled
together and moved with the governors bodily along the shaft so that in one position
the forward cams (or other device) work the valves and in the other the backward
cams (or other device) work the valves when in the central position all the valves
may be made to remain closed if required. We put relief valves in the cylinder
covers.
It is not necessary that the governors should be mounted. on the shaft but they
may be in any position so that they are moved with the cams (or other device). In
engines with more than one-cylinder either simple or compound the same cams may
be made to work the valves of all the cylinders. We prefer to place the valves in
the cylinder covers but this is not necessary. The valves may also be worked by the
piston rod or any reciprocating part of the engine by means of levers, catches, wedges
or other device. If it is not desired to regulate the admission or cut off by the
governors the same may be done by hand with any arrangement for moving the cams
(or other device). It is obvious that instead of moving the cams (or other device)
the lovers working on the cams may be moved so as to gear with any different part
of the cams (or other device).
CM 1000
SYLVANUS EDDINGTON.
JOHN EVAN STEEVENSON.
COMPLETE SPECIFICATION.
Improvements in Valve Gear of Engines Worked by Steam or
Compressed Air or other Gases.
•
We SYLVANUS EDDINGTON..and JOHN EVAN STEEVENSON both of Chelmsford in
the County of Essex Engineers 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 improvements in that class of valve gear in which the
steam or other motive agent is admitted to and exhausted from the cylinder by valves
actuated by means of cams, mounted on a counter shaft the aforesaid valves being of
the double beat or equilibrum type and is more particularly designed to provide a
simple and effective method of reversing the motion of the engines.
The cams actuating the admission valves are by our invention formed as double
cams (one for each direction of the engine) and are attached to the govenors and

page_text: with them carried loosely on but driven by the said counter shaft. The cams
actuating the admission valves being of the spiral form the said valves are closed
sooner or later in the stroke of the engine according to the action of the
。 govenors. The cams actuating the exhaust valves are also double and carried on
the same shaft.
辈
When it is desired to reverse the engine the govenors and the whole of the
cams are moved along the shaft thus bringing the opposite set of cams into
gear.
On the accompanying two sheets of drawings
Figure 1 of sheet 1 shews a plan and
Figure 2 a sectional elevation of an arrangement according to our invention of
valves and gear as applied to a steam engine and
On sheet 2 Figures 3 and 4 shew a different arrangement for the same
purpose.
Referring to the said drawings and to the letters of reference marked thereon-
A is the cylinder B the piston of an ordinary engine. C are the steam admission
valves and D D' the exhaust valves. E E are the govenors carried on the hollow
shaft F.
The hollow shaft F is mounted in bearings G at right angles to and is driven by
the crank shaft through mitre gear H in any well known manner.
The end of the govenor nearest the crank shaft is formed with a groove 1 in which
engages a fork from an ordinary reversing lever_or the like by means of which the
govenors and cams can be moved with the shaft F.
Attached to the opposite ends of the govenors are the cams K K' for actuating.
the admission valves these double cams are formed in one hollow block or piece sliding.
on the hollow shaft F.
The cams L L actuating the exhaust valves are, in the arrangement shewn on
sheet 1, fixed on the hollow shaft F by means of a set screw a or other device.
The cams K K' and L L' actuate the admission and exhaust valves by means of
levers M M¹ and N N¹ and cranked spindles 0 0 0 0.
In figures 1 and 2 the cams K and L are shewn in gear and in order to
reverse the engine the shaft with govenors and cats mounted thereon is pushed
forward by means of the reversing lever or the like so bringing cams K and L
into gear.
On sheet 2 Figures 3 and 4 shew a modification of our invention in which
the valves are placed in the cylinder covers, and in order to apply our invention
to this arrangement it is only necessary to duplicate the whole of the cams before,
described connecting the govenors to the cams actuating the admission valves by
means of a rod-P working inside the hollow shaft F.
It is obvious that there may be many variations of the foregoing arrangments for
instance instead of moving the shaft in reversing the engine the govenors and cams
may be coupled by means of a rod working in the hollow shaft or the govenors may
be vertical driven by bevel gear and connected to the cams by means of cranked levers
or other device.
The same object may be attained by fixing the govenors and bringing the
reverse set of cams into gear," by, lengthening or shortening the distance between
the cams and govenors by any suitable means well known to any mechancal
engineer.
1..
It will be seen that although our drawings shew our invention as applied to a
horizontal engine, it is equally applicable to vertical engines
Having now particularly described and ascertained the nature of our said inven-
tion and in what. manner the same is to be performed we declare that what we
claim is :-
what we
First-In self-acting expansion engines constructed with equilibrum double beat
or similar valves worked by cams mounting the govenors and the cams actuating the
admission and exhaust valves on the same shaft.
.
J

page_text: Second-In engines constructed with equilibrum double beat or similar valves
worked by cams arranging such cams and govenors in the manner described in the
foregoing specification and as illustrated by the accompanying drawings for the
purpose of reversing the engines.
Third-The general arrangement of valve and reversing gear for engines sub-
stantially as herein described and as illustrated by the accompanying drawings.
Dated this 24th day of Feb
1900
POPPLEWELL & Co.,
17 & 18, Southampton Buildings, London, W.C.