Improvements in Tappet-actuated Valves for Reciprocating Engines.
Year: 1891

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by THE INGERSOLL SERGEANT DRILL COMPANY,
a Corporation organized under, and existing by virtue of, the laws of the State
of West Virginia, and having its principal business office at No. 10, Park
Place, in the City of New York; State of New York, United States of
America.]
Improvements in Tappet-actuated Valves for Reciprocating
Engines.
I, PHILIP ARTHUR NEWTON of the Office for Patents, 6 Bream's Buildings,
Chancery Lane, in the County of Middlesex, Patent Agent, 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 that class of valves for reciprocating engines which are
actuated by the engine piston striking or working in contact with tappets which
are provided on the valve, and which project into the cylinder, such valves being
especially applicable to the cylinders and pistons of the engines employed in rock
drilling machines, in which the drill is carried by the piston rod.
I will now proceed to describe the invention with reference to the accompanying
drawings, and afterwards point out its novel features in claims.
Fig. 1 represents a longitudinal sectional view of the cylinder, piston, and valve
of the engine of a rock drilling machine, embodying the invention,-the section
being taken on the line of Fig. 2.
Fig. 2 is a plan view, with the valve, the valve-seat plate, and the steam chest
cover in section in the line y-y of Fig. 1.
Fig. 3 represents a transverse section in the line 2-s of Figs. 1 and 2.
Fig. 4 represents a face view of the valve.
5 represents a transverse section of what is hereinafter called the "seat
Fig; detached from the engine; and
plate"
Fig. 6 is a plan view of the same.
Fig. 7 is a view corresponding with Fig. 1, showing the piston and valve in a
different position.
Similar letters of reference designate corresponding parts in all the figures.
A designates the cylinder, having a longitudinal parallel-sided opening a about
midway between its ends, to contain the valve tappets.
B is the piston, which is reduced in size between the ends, to produce two
inclined surfaces or shoulders 6 6', which face each other, for acting upon the valve
tappets.
CD designate what may be termed the "seat plate," the form of which is angular
in its transverse section, as shewn in Figs. 3 and 5, and which is cored out to form
passages c c and d, for the steam or other motive fluid by which the engine is
actuated. The part C of this seat plate which constitutes a flat base, is fitted to a
corresponding face e on the cylinder surrounding the opening a in the latter, and
it has in it an opening f, which may be of any suitable width, but the length of
which is less than that of the opening a, as shewn at 9, 9 in Figure 1, to constitute
the tappet-stops, as hereinafter more fully explained. The part D of the said seat-
plate projects from the base C perpendicularly thereto, to form a flat valve face h,
which is approximately radial to the axis of the cylinder A, as may be understood
by reference to Figure 3.
The passages cc and d terminate in ports c", c* and d in the face h, and the
passages c, communicate with corresponding passages i, ¹ leading to opposite
ends of the cylinder. The arrangement of the ports e, 1 is the same as in many

page_text: well known D slide valve seats. The passage d opens, through the side of the
base C, as shewn in Figure 3, and has connected with it the exhaust pipe F, the
portion of the base containing the said passage d being extended Interally, as
shewn at C¹ in Figs. 2, 3, and 6, for the purpose of facilitating the making of such
connection.
G designates the slide-valve, which in its profile, as seen in Figures 1 and 4, is of
substantially the form of an inverted letter T, having wings j, j and k. The two
wings,, which are opposite, or nearly in line with each other, constitute tappets,
and the wing k, which is arranged centrally between the wings ; j', and has a flat
face, constitutes the valve proper, the said face having in it two cavities ↳ 1ª,
properly proportioned to the ports in the valve seat, to constitute a double
D valve. The lower part of this valve, which is flat, and constitutes the tappetsj,j',
fits easily in the opening a in the cylinder, as may be understood by reference to
Figs. 1 and 3, and the tappets project under or beyond the stops g 9, as shewn in
Fig. 1, while the valve-face k' is in contact with the seat h. The valve is held in
place by means of a pin n, which passes through a circular opening m, provided
centrally in the valve, at the junction of the wings j, j, k, and through corre-
sponding openings in the cylinder on opposite sides of the opening
a. The
said pin constitutes the pivot on which the valve oscillates, and is secured in
place by nuts m'. The valve is held to its seat h by pressure of the motive fluid
on its back.
H designates the cover, which combines with the base C of the seat-plate to
constitute the chest which receives, through the pipe L, from the boiler, or reservoir,
the steam, air, or other fluid by which the engine is to be driven. This cover
conforms to the lateral profile of the base C, as may be understood by comparison
of Figures 2 and 6, so that the same stud-bolts and nuts p, may secure both
together and to the cylinder, and afford easy access to the valve and seat by simply
taking off the nuts p and lifting off the cover H. The valve thus constructed and
applied is moved in one direction and the other alternately, across the seat, by the
action of the facing inclined surfaces or shoulders 6 6 on the piston upon the
tappets, to admit steam or other motive fluid to the cylinder at opposite ends
alternately, and is stopped in either direction by one of the stops 9, 9 which are
outside of the tappets.
In Figures 1 and 2 of the drawings, the cylinder is supposed to be taking steam
through the left hand port c", the steam entering under that part of the D cavity /
which projects beyond the seat, and the exhaust to be taking place from the right
hand end through the D cavity from the port to the port d", and the piston
is moving to the right. As the piston proceeds in the stroke, its inclined surface or
shoulder 6 throws the valve over to the reverse position shewn in Figure 7. After
completing the movement of the valve in either direction, the inclined surface or
shoulder bor b', which has operated upon it, passes by the tappet, and the other
portion of the piston, which fits the cylinder, passes under or behind the tappet,
and holds it to the stop g, against which it has been brought, and so prevents any
recoil of the valve being produced by the tappet striking the stop in the rapid
working of the piston. The valve is in this way locked between the piston and the
stop y during the completion of the movement of the piston in either direction, and
during the first part of its return movement.
In order that the face-wing of the valve may be made of sufficient length,
greater than that of the tappet wings, to permit a desirable length of movement of
the valve on its seat without its being liable to acquire an objectionable amount of
momentum in the rapid movement which is necessary for the valves of direct action
reciprocating engines, for most purposes, it is desirable that the said wing k should
be made as light as possible, yet it is desirable that the tappets should have all the
strength and breadth of bearing possible.
To thus lighten the face wing, and yet obtain a desirable width of tappet face,
the wing k is made thinner or narrower than the tappet wings in a direction parallel
with the axis of oscillation of the valve. As shewn in Figure 3, the face wing is

page_text: only half the width of the tappet wings. This proportion brings the valve face
central to the width of the tappets.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed (as communicated to me from
abroad), I declare that what I claim is :-
1. The combination, with the cylinder of a reciprocating engine having a longi-
tudinal opening for valve tappets, and a piston in said cylinder having inclined
surfaces or shoulders which face each other, of a valve having tappets which enter
said opening, and fixed stops outside of said tappets, against which the said tappets
are held by the piston, when the valve has completed its movement in either
direction, substantially as herein set forth.
2. The combination, with the cylinder of a reciprocating engine having in it a
longitudinal opening for valve tappets, of an oscillating valve having its face
approximately radial to the axis of said cylinder, and having tappets situated
within said opening, and a seat-plate for said valve partly covering said opening,
and the tappets within it, to constitute stops for the tappets to control the movement
of the valve, substantially as herein set forth.
3. The combination with the cylinder having the tappet-opening a, the angular
seat-plate C D, having the opening opposite the said tappet-opening a, but partly
overlapping said opening, to form tappet stops 9, 9, and the oscillating valve G,
having its axis of oscillation within said tappet-opening, having tappets jj¹ behind
the so-formed stops, and having its face k perpendicular to its axis of oscillation,
and projecting through the said opening fin the seat-plate, and in contact with the
corresponding seat h on said plate, substantially as herein set forth.
4. The three-winged oscillating tappet valve, having one wing, which constitutes
the valve face, narrower or thinner in a direction parallel with the axis of oscillation
than the other two wings, which constitute the tappets, substantially as and for the
purpose herein set forth.
Dated this 8th day of September 1891.
NEWTON & SON,
Agents for the Applicant.