IMPROVEMENTS IN VALVES AND ADJACENT PARTS OF OSCILLATING AND OTHER STEAM ENGINES, WATER ENGINES, METERS AND PUMPS
Year: 1882

page_text: LETTERS PATENT to Abraham Wyke Harrison of Abergavenny in the
county of Monmouth, for an invention of "IMPROVEMENTS IN VALVES AND
ADJACENT PARTS OF OSCILLATING AND OTHER STEAM ENGINES, WATER
ENGINES, METERS AND PUMPS
"
"
PROVISIONAL SPECIFICATION left by the said Abraham Wyke Harrison
at the Office of the Commissioners of Patents on the 9th March 1882.
ABRAHAM WYKE HARRISON of Abergavenny in the county of Monmouth.
'IMPROVEMENTS IN VALVES AND ADJACENT PARTS OF OSCILLATING AND OTHER
STEAM ENGINES, WATER ENGINES, METERS AND PUMPS.'
"
This invention has for its object a simple cheap valve apparatus, one that can be
examined without difficulty and that will work with little friction.
As arranged for oscillating steam engines the two cylinder ports are arranged on
opposite sides of the trunnion. The valve consists of a simple plate worked by an
eccentric or if desirable link or other motion. This plate is pierced with four ports
forming segments of circles round the trunnion, the inner two being oblique trans-
versely and preferably much wider on the cylinder side than on the other.
The valve works between two faces.
The opposite face to that on the cylinder is armed with four ports also forming
segments of circles having a radius equal to half the length of the valve, the two
outer ports being preferably connected with the steam the two inner with the
exhaust, between these are the trunnion and its bearings. The valve is cut away
in the centre to go round the trunnion. The trunnion is supplied with conical
bearings so as to be screwed up as it works loose; and against the trunnion
opposite the valve I cause a spring or other pressure to bear so to counteract the
slight pressure on the valve.
In valves for fixed cylinders similar mechanism can be adopted simplified in
this case by the absence of trunnions. The pressure on valve can still be counter-
balanced by a spring and the ports can be straight and not curved. The two inner
ports can be united in a single central exhaust.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Abraham Wyke Harrison in the Great Seal Patent Office on the
9th September 1882.
ABRAHAM WYKE HARRISON of Abergavenny in the county of Monmouth
"IMPROVEMENTS IN VALVES AND ADJACENT PARTS OF OSCILLATING AND OTHER
STEAM ENGINES, WATER ENGINES, METERS, AND PUMPS
This invention is designed for application to Steam engines, Water Motors,
Pumps and Similar apparatus in which the fluid is admitted or expelled from a
cylinder through ports or openings controlled by the motion of a valve.
This invention has for its object a slide valve apparatus that will require little 1
power to move it, that will waste only a minimum amount of the fluid passing
through the ports, that can be examined without difficulty, and that will be cheap
and lasting.
In the drawings the invention is shown as applied to a simple form of steam-
engine made to take the steam the full stroke but it is equally applicable to 1
compound engines, or engines which cut off the steam before the end of the
stroke. For water motors the ports and passages should be made larger than those
shown.
Fig 1. Is a side elevation of cylinder of oscillating engine fitted with my
invention. The passages in steam chest are shown in dotted lines.
Fig 2-Sectional plan of same showing cylinder ports and valve
Fig 3-End elevation
Fig 4-Valve showing face that works against the cylinder
Fig 5 Face of cylinder that works against the valve.
Fig. 6-Face of steam chest that works against the valve
Fig 7 Plan half in section, of apparatus as applied to fixed cylinder
Fig 8-Side elevation of same
Fig 9 End elevation of part of same showing relative positions of steam chest,
valve, and cylinder, Throughout the drawings similar letters of reference refer to
like or corresponding parts shown in the several Figs.
Referring especially to Figs 1 to 6 inclusive, A is a steam chest somewhat
C-shaped so as to avoid the trunnions and formed with steam ports B B¹ preferably
connected by passage b and exhaust ports C C₁ connected by passage C in either
case however the ports could open into separate pipes in which case the connecting
passages in the steam chest can be dispensed with. This steam chest is fixed and
supplied with one or two, as the case may be, exhaust pipes E, and steam pipes S
D is the cylinder oscillating on solid trunnions F F. G bearings for trunnions
HH' cylinder ports made nearly straight and consequently having as little waste
steam space as possible. I slide valve also somewhat C-shaped to avoid the
trunnions, and pierced with steam ports J J¹ and exhaust ports K K¹; this valve
has a planed surface on each side, working against parallel planed surfaces on the
cylinder and steam chest which are kept up to their faces by spring with set pin
or other suitable means. It will be seen that the ports are all curved so as to
accommodate themsèlves better to the oscillation of the cylinder. The port K is
shown wider on the steam cylinder side than on the side next the steam chest as
this shape has been found to be more easy to mould than diagonal as shown K¹,
though either will answer the purpose.
The slide valve works between guiding lugs L (shown in Fig 3) on the steam
chest, it is worked by an eccentric on the main shaft, link motion or other valve
gear linked to it at M or with tappets secured to valve and cylinder The bearing G

page_text: of the trunnion is made conical as shown to take up any wear and tear, but if
desirable ordinary bearings could be used.
In Figs 7. 8. and 9. the same Figures and description will in great part hold
good but here as the cylinder is stationary the exhaust can be carried out the
usual way as shown in Fig 7. and the cylinder ports are brought down nearer to
the centre and open into a short valve face in the usual manner The steam chest
too instead of being supported on the foundation bed is carried on the cylinder
being held to it by studs O, armed with nuts N, and springs P, to keep it close up
to the valve, and thus while preventing the escape of steam not pressing so tight
as to cause much friction and giving way slightly to uneven thicknesses of the
valve if such there be.
The mode of action is so manifest to any one familiar with steam cylinders and
slide valves that it is needless to describe it. It however differs in one remarkable
point from other slide valves, in that in the case of oscillating cylinders it has two
motions relative to the cylinder, its own rectilinear reciprocating motion, and the
cylinders oscillating motion. Through this circumstance it is found that while
other slide valves and cylinder valve faces are apt to wear into grooves, mine wear
uniformly, a great advantage. Another striking advantage of my valve is, that on
shutting off steam it can be at once disconnected from the eccentric and lug, and
withdrawn, and the faces and ports examined without disturbing any other part
whereas all other slide valves that I know of are in steam chests, and can only be
got at by breaking the joint and taking off the steam chest cover after which
before the engine can be got to work the joint must be remade steam-tight. Again
in oscillating engines the need of hollow trunnions with all their expensive manu-
facture and complications is avoided while the trunnions being solid and not heated
by steam can be made much smaller in diameter and thus a great source of friction
and of heated bearings is avoided they can thus be made too to terminate in the
bearings and without other non-oscillating surface such as steam pipes being
attached
Having now described my invention and the best mode known to me of carrying
it into effect, I wish it to be understood that what I believe to be new and desire
to claim under the hereinbefore in part recited Letters Patent is
1st The manufacture of a valve for oscillating or other steam engines, water
engines, Meters or Pumps formed of a perforated plate with parallel surfaces reci-
procating between faces perforated with ports on the cylinder and steam chest
respectively substantially as described.
2nd The arrangement by which the valve is kept tight between the steam chest
and the cylinder by making one of these moveable and attaching it to the other
with bolts and springs substantially as described.
3rd The manufacture of valves and adjacent parts of oscillating or other steam
engines water engines, meters or pumps constructed and arranged substantially as
set forth in the specification or any of the accompanying drawings.
In witness whereof I the said Abraham Wyke Harrison have hereunto set
my hand and seal this fourth day of September in the year of our Lord
one thousand eight hundred and eighty two
ABRAHAM WYKE HARRISON (LE)