IMPROVEMENT IN VALVE-MECHANISM FOR DUPLEX STEAM PUMPS
Year: 1885

page_text: COMPLETE SPECIFICATION
I, JAMES RILEY MAXWELL, of Hamilton, Butler County, State of Ohio, United
States of America, Manufacturer, do hereby declare the nature of my invention for
IMPROVEMENT IN VALVE-MECHANISM FOR DUPLEX STEAM PUMPS," and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement
In what are termed duplex steam pumps two steam engines are placed closely
side by side, and the valve of each engine is actuated by the piston rod of the other
engine, the transmission between piston rods and valve-stems being effected by
means of levers In most duplex steam pumps both slide valves are alike, being
generally in the well known D-form In such case the transmitting levers,
through which the valves receive their motion, must be of different order, for
instance, one being a lever of the first order, the other a lever of the second order
In cases where one of the valves is a D-valve, and the other a B-valve, the
transmitting levers may be of identical order
My invention relates to the arrangement of mechanism for transmitting motion
from the piston rods to the valve-stems of duplex steam pumps
My improvement will be readily understood from the following description taken
in connection with the accompanying drawing, in which
1
Fig 1 is an end view of a device illustrating my improvement, the direction of
view being indicated by the arrow 6 on other figures
Fig. 2 a plan of the same, direction of view being indicated by arrow a on other
figures.
Fig 3 a side view of the same, direction of view being indicated, by arrow con
other figures
I
Fig 4 a face view of the lever H, the direction of view being indicated by-
arrow & on Fig 1
Fig 5 a face view of lever J, the direction of view being indicated by arrow e
on Fig 1. Fig 3 18 best viewed by turning the sheet so the levers project
lownward
In the drawing A represents the usual steam chest, intended to contain both
lide-valves, B, the bracket projecting forward from the front of the steam chest,'
etween the valve-stems, C, one of the usual valve-stems, D, the other valve-
tem, E, lugs for guiding the valve-stems, projecting from the sides of the bracket,
[Price 6d 1

page_text: F, one of the usual piston rods of the machine, G, the other piston rod, H, a
diagonally disposed lever, of the second order of levers, adapted to transmit motion
from the piston rod G to the valve-stem C, I, the fulcrum bearing of the lever H,
formed by a mortise in the arm at the end of the bracket and engaged by the
upper end of the lever, J, another diagonally disposed lever, of the first order of
levers, adapted to transmit motion from the piston rod F to the valve stem D,
and, K, the fulcrum bearing of this lever formed by a pair of jaws between which
engages the fulcrum-boss of the lever
The two levers are disposed in planes intersecting each other, one lever being
disposed in advance of the other in order that they may not interfere with each
other The reciprocating motion of the piston rod F is transmitted, through the
lever J, to the valve-stem D, and the reciprocating motion of the piston rod G 19
transmitted, through the lever H, to the valve-stem C, the motions and effects
being such as 18 common and well known in connection with duplex steam pumps
The valve-stems, being guided in the lugs E, partake of reciprocating motions in
a right line, and the piston rods also, as usual, reciprocate in a right line
The lower ends of the levers, instead of being provided with the usual link
attachments, are provided with cylindrical swells engaging grooved collars secured
to the piston rods
As the points of valve-stem attachment of the levers move in a right line it is
obvious that the fulcrum points of the levers, and also the ends which engage the
piston rods, must approach and recede from the plane of the valve-stems during the
Oscillations of the levers This movement of approach and recession is permitted
at the lower end of the levers by a sliding of the end swells in their grooves, and
at the fulcrum point by the sliding of the fulcrum-bosses in their seats, in an
obvious manner The valve-stems are provided with the usul eyes, and the valve-
stem points of the levers have projecting Journals cast upon them which the eyes
engage In the case of the lever H it will be seen that the lever is supported in
position by its engagement with the valve-stem, which is placed underneath the
lever, and by the collar of the piston rod G, which is also underneath the lever,
and the same may be said of the lever J
Upon the back of the lever H, directly opposite the eye of the valve-stem C, a
finished bearing spot is provided to rub against the finished bearing surfaces on the
under-side of the arm which carries the fulcrum mortise I A side bearing is thus
provided for the lever to keep it into neat side engagement with the eye of its
valve-stem The lever J, in a similar manner, is provided with a finished side-
bearing spot, to the rear of its fulcrum point, engaging the finished bottom of the
seat between the jaws which it engages
By this arrangement a snug fitting of parts is secured with a trifling amount of
machine finish, and the system permits of a ready construction of parts upon the
interchangeable plan of machine manufacture.
The advantage resulting from the combination of the different features of this
simple improvement may be well comprehended when I explain that I transmit the
motions from the two piston rods to the two valve-stems by means of two simple
levers of exceedingly cheap construction, while previous constructions adapted for
precisely the same ends, have involved the use of links, two-part levers, rock-shafts,
studs, nuts, etc., forming an aggregate of twenty-six pieces
-
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim 1s
1. In a valve-operating mechanism for duplex steam pumps, the combination,
with two piston rods and two valve-stems, of two diagonally disposed levers
arranged in planes intersecting each other, substantially as and for the purpose set
forth.
2 In a valve-operating mechanism for duplex steam pumps, a steam chest, a

page_text: arranged in planes intersecting each other and fulcrummed in supports in said
bracket, combined substantially as and for the purpose set forth
3 In a valve-operating mechanism for duplex steam pumps, the combination of
a steam chest, two valve-stems, a bracket projecting outward from the steam chest
between the two valve-stems, a pair of diagonally disposed levers arranged in
planes intersecting each other, fulcrum supports for the levers upon the bracket,
and guiding lugs for the valve-stems projecting from the sides of the bracket,
substantially as and for the purpose set forth
4 In a valve-operating mechanism for duplex steam pumps, the combination
with two valve-stems and two piston rods, of a diagonally disposed lever of the
first order, and a diagonally disposed lever of the second order, the two levers
being arranged in planes intersecting each other, substantially as and for the
purpose set forth
5 In a valve-operating mechanism for duplex steam pumps, the combination
with two valve-stems and two piston rods, of a pair of levers diagonally disposed
in planes intersecting each other, Journals projecting from the levers into engage-
ment with eyes on the valve-stems, fulcrum-bosses on the levers engaging fulcrum
Jaws, and fulcrum-bosses on the ends of the levers engaging grooved collars upon
the piston rods, substantially as and for the purpose set forth
6 In a valve-operating mechanism for duplex steam pumps, a pair of valve-
stems arranged to reciprocate in right lines, a pair of piston rods arranged to
reciprocate in right lines, a pair of levers, one engaging each valve-stem and the
Fiston rod which actuates it, the levers being attached to the valve-stem, as set
forth, so that such attaching point of each lever moves in a right line with its
valve-stem, and attached to their fulcrum supports and to the piston rod which
drives them in such manner, as set forth, that the piston rod points and fulcrum
points are capable of approach and recession with reference to the point of valve-
stem attachment, substantially as set forth
7 In a valve-operating mechanism for duplex steam pumps, the combination of
steam chest A, bracket B, valve-stems C, D, provided with eyes, guide lugs E,
piston rods F and G provided with grooved collars, levers H and J provided with
journals engaging the eyes of the valve-stems, with fulcrum-bosses, and with end
swells engaging the grooved collars, and the jawed fulcrums I and K formed on
the bracket B, substantially as and for the purpose set forth.