Improvements in Valve Gear for Direct Acting Steam Pumps, Applicable Generally where a Reciprocating Motion only is Required.
Year: 1888

page_text: Date of Application, 18th May, 1888
Specification Accepted, 13th July, 1888
COMPLETE SPECIFICATION.
Improvements in Valve Gear for Direct Acting Steam Pumps,
Applicable Generally where a Reciprocating Motion only is
Required.
⚫I EDWARD LUND Junr. of 2 Ellesmere Terrace, Edge Lane, Stretford in the County
of Lancaster, Engineer, do hereby declare the nature of my said 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 direct acting steam pumps and also to a
simple and reliable arrangement of mechanism for moving in an easy and noiseless
manner the valve rod or rods employed in such pumps and which motion is equally
applicable for moving the valves of other classes of pumps or the valves of any engine
or motor where a reciprocating motion only is required.
This mechanism consists essentially of an anchor-shaped rocking-arm or tappet-
lever applied to the valve rod or rods to be moved and which arm is caused to rock to
and fro under the tappet action of a roller carried by the main piston rod as I will
now proceed to describe.
. On the accompanying drawing Fig. 1 is a side view Fig. 2 a plan and Fig. 3 a
transverse section (taken on the line a-b in Fig. 1) of a horizontal direct acting
steam pump having my improved valve actuating mechanism applied thereto.
In all the aforementioned views a is the steam cylinder b the pump cylinder and c
the main piston rod connecting the piston and pump plunger together in the usual
manner, d is the auxiliary steam cylinder and e, the slide valve chamber placed one
above the other, and each having its piston and valve rod extending forward parallel
to each other and indicated by the letters fand g respectively. These rods are each
furnished with my improved screwed tappet collar as illustrated on an enlarged
scale by front and transverse section in Figs. 5 and 6. These screwed tappet collars
being formed as half nuts and screwed upon the rods are thus capable of minute
adjustment whilst when tightened by the bolts y the screw thread affords a perfect
security against such collars moving along the rods.
his my improved tappet lever or rocking arm mounted upon the horizontal stud i
bolted to the framework as seen more clearly in Fig. 3. The longer or upright arm

page_text: of this tappet lever is made with a pair of slots at its extremity which embrace the
auxiliary piston rod and slide valve rod g and between their respective screwed
collars, a.
kis the actuating tappet roller mounted in the coupling box or cross-
head secured to and carried to and fro by the main piston rod c. This tappet roller
or projection is so placed as to come in contact alternately with one arm and then
with the other arm of the tappet lever h to cause such lever to tilt over, in the
direction in which the piston rod is travelling and thus to cause the longer arm by
coming in contact with the screwed tappet collars on the rods and to travel to and
fro in the same direction as the main piston rod is then moving.
It will be observed that owing to the curved shape of the shorter arm of the tappet
lever the tappet roller k only comes in contact with the arm as the piston approaches
each end of its stroke and thus I am enabled to move the auxiliary slide valve rod and
auxiliary piston rod by an easy and noiseless movement of the actuating arm.
In vertical pumps I employ the same description of mechanism for moving the rods
as I do in horizontal pumps only as the tappet lever is mounted horizontally I find it
necessary to counterbalance the same by an adjustable weight, as indicated in Fig. 4
or by an equivalent spring.
In Figs. 7 and 8 I illustrate my improved tappet mechanism applied to work
vertically in horizontal pumps Fig. 9 being a cross section of Fig. 7 on the
line c-d.
In this arrangement I employ a vertically pivoted rod for carrying the curved
arms and provided with projecting forked arms m and n for embracing and
moving the auxiliary slide valve rod g and auxiliary piston rod f.
The action of this arrangement will be seen to be similar to that described in
Figs. 1. 2 and 3.
In Fig. 10 I illustrate a side sectional view in Fig. 11 a transverse section and in
Fig. 12 a plan view (with the steam chest cover removed) of a steam pump con-
structed in accordance with another part of my improvements and in which only one
rod is employed to move both the auxiliary slide valve and the auxiliary piston rod.
This arrangement is effected by having the auxiliary cylinder o affixed as usual
upon the top of the main cylinder p of a horizontal steam pump, but the steam
chest or slide valve chamber q is carried forward and secured in the same horizontal
plane upon a bracket projecting from the frame work 2. Through this steam-
chest and passing through stuffing boxes at each end thereof is a hollow sleeve or
valve rods which permits the auxiliary piston rod t to be carried forwards and
completely through such hollow sleeve which sleeve is embraced by the slotted
extremity of the tappet lover u acting between the adjustable screwed tappet collars r
mounted upon such sleeve as illustrated:
In Fig. 13 I illustrato a side exterior view of one side of the auxiliary cylinder o
and in Figs. 14 and 15 a similar side exterior view and transverse section of the
steam chest shewing the triple passages which are alike on both sides of such
cylinder and steam chest and are connected together by preference by the cast iron
side pipes v.
These side pipes have three corresponding sets of passages w formed
through them as illustrated more clearly by dotted lines in the separate side view
Fig. 16 the one side pipe being used for conveying steam and the other forming the
exhaust and all controlled by the auxiliary slide valve A a side view of which is
represented in Fig. 17 and an inverted plan view in Fig. 18.
The action of this arrangement may be described as follows:-
When the piston B has nearly completed its stroke the roller C depresses or moves
the tappet lever and thus by imparting motion to the hollow sleeve s admits steam
to move the auxiliary piston o' and should this fail to take place quickly enough, the
end of the hollow rod or sleeve's comes in contact with the screwed tappet collar a
(or the collar as the case may be) and causes the same to proceed in the same
direction as the main piston B thus pushing the auxiliary piston rod t (and main slide
valve) and so rendering the reversing of the engine certain.
The arrows in the passages indicate the direction of the steam and exhaust when the
main piston-is taking its forward stroke.

page_text: In Figs. 19 and 20 I represent a side elevation and partial plan view of the same
auxiliary cylinder and valve chamber as in Figs. 10 to 12 but with the auxiliary
piston rod D and valve rod E separated and the latter provided at one extremity with
a strap or link F and the former fitted with a pair of my improved screwed tappet
collars one fixed upon the auxiliary piston rod inside and the other outside the
link f. In Fig. 21 I also represent the same slide valve chamber but with the
auxiliary steam cylinder enlarged sufficiently to have the slide valve rod G to pass
completely through the auxiliary piston rod H which is formed hollow for the
purpose.
The action of these two last modifications will be sufficiently apparent without
furthur description-the same reference letters being used in both cases to indicate
similar parts to those which are also employed in Figs. 10 to 12.
It will thus be observed that in all cases I so mount the tappet lever as to move
the slide valve or other rod in the same direction as the main piston rod and whereby
I obtain a simple, noiseless and easy actuating motion.
Having thus particularly described and ascertained the nature of this my said
invention and in what manner the same may be performed I declare that what
I claim is :-
1st. The improved combination and arrangement of direct acting steam pumps
substantially as hereinbefore described and illustrated on the accompanying drawings.
2nd. The employment of a tappet lever or its equivalent when mounted so as to
move the valve rod or rods in the same direction as the main piston of a pump, engine
or other motor substantially as and for the purpose hereinbefore described and
illustrated on the accompanying drawing.
3rd. The improved adjustable screwed tappet collars for the valve rods of steam
pumps and for other analagous purposes substantially as herein before described and
illustrated on the accompanying drawings.
Dated this 17th day of May 1888
JOHN G. WILSON,
Patent Office,
55, Market Street, Manchester,
Agent for the Applicant.