Improved Apparatus for Actuating the Valves of Steam Engines and similar Motor Engines.
Year: 1890

page_text: Date of Application, 30th May, 1890
Complete Specification Left, 25th Feb., 1891-Accepted, 9th May. 1891
PROVISIONAL SPECIFICATION.
Improved Apparatus for Actuating the Valves of Steam Engines
and similar Motor Engines.
1. HERMANN FRANZ GÜNTHER MELTZER of 19 Göthe Strasse Charlottenburg,
Germany Engineer do hereby declare the nature of this invention to be as
follows:-
This invention relates to apparatus for actuating the valves of steam and other
engines which is distinguished from known valve gear, in that the degree of cut off*
can be varied at pleasure between the widest limits and in such manner that a
reaction on the governor does not take place, and that all the periods for taking
steam can be varied independently of each other.
For this purpose a crank pin or eccentric on the engine shaft is connected by a
rod to a sliding bar working between guides, parallel to the cylinder, in such
manner that the position of the bar always corresponds to that of the piston.
This sliding bar serves to actuate both the supply and exhaust valves of the
engine, for which purpose it is combined with mechanism of the following
construction.
The sliding bar is formed on its outer side with two oppositely inclined faces,
each of which has two longitudinal grooves extending along its entire length, one of
which is of greater depth than the other. Into one or other of these grooves enters
a stud on the one end of a rod the other end of which is connected to an elbow
lever that actuates, in the one case one of the admission valves and in the other
case one of the exhaust valves of the cylinder, these valves being situated on
diametrically opposite sides of the cylinder, in positions at right angles to the axis
of the cylinder. The ends of the rods next the sliding bar pass through eyes,
whereby, while they can move freely in a longitudinal direction they are prevented
from shifting laterally.
The rods are acted upon by springs so as to keep their studs in contact with the
grooves of the bar.
I will in the first instance describe the action of the rods that work the exhaust
valves of the engine. When the stud of the rod is in the higher, shallower, groove
of the slide, it causes the lever to close the exhaust valve, and it is held in this
position as the slide is moved along during the stroke, until at or towards the end
of the stroke, an adjustable incline on the slide bears against the stud and forces it,
together with the rod to move downwards until it passes the edge dividing the
upper shallow groove from the lower, deeper groove, whereupon the spring of the
rod causes the stud to spring into the lower groove, whereby the rod will have
moved the exhaust valve into the open position and will be made to hold it there
during the return stroke. At or near the end of the stroke, a second adjustable
double incline, first raises the stud of the rod out of the deep groove by means of
an incline or wedge face resting in the groove, and then by means of a second
incline pushes it upward into the shallow groove again, thus again closing the
exhaust valve for the next stroke.
The steam supply valves are operated by two sets of inclines in the same manner
as above described with reference to the exhaust valves, with the exception that
the double inclines effect the moving of the studs and their rods from the open
position to the closed position and are not situated at the ends of the slide, but at
an intermediate point of its length, corresponding to the amount cut-off required,
and they are arranged so as to be shifted from one point to another, so as to vary
the cut off, for which purpose the following mechanism is employed.
Each of the double inclines for the two supply valve rods has attached to it a

page_text: rack rod, the rack rod of the one incline being situated over that of the other
incline which rests upon the inclined face of the sliding bar. Into these rack rods
gear two toothed pinions rotatable on axes fixed to the sliding bar. The two
pinions are so arranged relatively to each other and to the two rack-rods that both
pinions gear with each other, but each one only gears with one of the rack rods, so
that on turning the one pinion by means of a crank handle, it firstly moves its rack
rod and the double incline connected thereto nearer to or farther from the incline
by which the opening of the valve is effected, and secondly it moves, by means of
the second pinion, the second rack rod and its double incline to precisely the same
extent in the contrary direction, thereby also bringing the latter in the same
relative position to its incline for opening the valve.
The shifting of the cut-off inclines may also be done automatically by the action
of the governor, by providing a rod with stops that is shifted by the governor and
that comes in contact with projections on the rack rods so as to move the inclines
for increasing or decreasing the cut off for variations of speed. The one rack rod
has a groove working on a feather on the sliding bar, for guiding the rod.
There being a supply valve and an exhaust valve, with their rods, at each end of
the cylinder, it will be seen that, the inclines for opening the exhaust valves will be
situated at each end of the sliding bar, while the double inclines for closing the
same are both situated at the middle of the bar, lying in opposite directions.
On the other hand, the inclines for opening the two supply valves are both
situated at the middle of the sliding bar, while the double inclines for the cut off
are situated at a variable intermediate point between the middle and the two ends
of the bar.
In order to admit of the accurate adjustment of the two inclines or wedge
surfaces of the double inclines in their respective grooves, there are by preference
made of separate pieces.
Dated this 30th day of May 1890.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improved Apparatus for Actuating the Valves of Steam Engines
and similar Motor Engines.
I, HERMANN FRANZ GÜNTHER MELTZER, of 19 Göthe Strasse Charlottenburg,
Germany Engineer, 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 apparatus for actuating the valves of steam and other
engines which is distinguished from. known valve gear in that the degree of cut-off
can be varied at pleasure between the widest limits and in such manner that a
reaction on the governor does not take place, and that all the periods for taking
steam can be varied independently of each other.
On the accompanying drawings
Fig. 1. shews a side view of steam engine with the said improyed apparatus
applied thereto.
Fig. 2. shews an enlarged cross section through the cylinder, and
Figs. 3 to 22 shew details.
The crank shaft a of the engine has a crank pin a', or it might be an excentric,
which is connected by a rod to a slide c.
This slide can travel between guides d in such manner as to be situated at the
dead centre at the same time as the engine piston. The stroke of the slide e is
determined by the distance apart of the mechanisms that actuate the valves.
The slide is made to actuate both the supply and exhaust valves. I will first

page_text: describe the mechanisms for operating the exhaust valves, as these are the more
simple, the duration of the exhaust being the same for all degrees of expansion.
The slide has on its outer side two inclined surfaces the inclination of which is
determined by the angular position of the rods e e' which are connected respectively
to the levers of the exhaust and admission valves. Each of these surfaces is
provided with two grooves, g, and of which g' is deeper than . Into the one or
other of these grooves takes a stud fixed to the upper end of the rod e. This
rod e is prevented by a guide through which the rod passes, from shifting in the
longitudinal direction of the cylinder, while it is free to move in a direction trans-
versely to the cylinder. By means of a spring k the upper end of the rode has a
tendency to approach the slide r, so that the stud will always be forced into the
one or other of the grooves or g'.
If the exhaust valve rod e assumes the position shewn in Figs. 2 and 3, the
corresponding exhaust valve will be closed, and the stud h enters the upper,
shallower, groove g
If the slide e moves from the position at Fig. 3 in the
direction to the right hand, the groove slides along under the stud until an
incline in the groove at the front end of the slide forces the stud h downwards.
When the upper edge of the stud has passed downward beyond the edge
separating the grooves and g', the stud will be caused by spring k to spring into
the deeper groove and the stud of the front valve rod will then be held in the
position in which the exhaust valve is open.
If therefore the slide now moves forward to the left, the stud of rod e will
during such motion be held-by-the-groove in the position corresponding to the
open position of the exhaust valve until a piece m situated in the groove at about
the middle of its length presses the stud / out of the groove, whereupon the valve
closes again. The piece m has for this purpose firstly an incline m which raises.
the stud out of the groove and a second incline m² which then forces the stud
upward, so that the latter again passes into the groove as at Fig. 3.
The piece m, which is made in two parts in order to allow of the accurate adjust-
ment of the inclines m', made double, that is, with inclines m' and m² on each
side, the one set being made to operate on the front valve rode while the other set
acts upon the back valve rod. A second incline corresponding to is also
provided at the rear end of the slide for acting upon the rear valve rod e as
described with reference to l.
The supply valves are operated as follows.
The studs of the valve rods e¹ are situated in the deeper groove of the slide
when the valves are open, and when they are closed the studs are situated in the
shallower groove g.
In the position shewn at Fig. 3 the front supply valve is open, while the rear
one is closed and the rear exhaust valve is open. The downward motion of the
studs is effected by an incline L which is also formed of two parts for ready
adjustment, and which comes into operation when by the motion of the slide, the
stud h¹ comes in contact therewith.
By means of springs the lower end of the rod el receives a tendency to move
downward into the grooves gg'.
The raising of the studs out of the deeper groove is effected by the pieces M
which, in this case, are not fixed to the slide e but can be shifted upon it as will be
presently described for the purpose of varying the cut-off.
These pieces M are provided firstly with inclines M', situated in the groove g
so as to raise the studs ' out of it, when the slide has arrived at a certain point of
its motion, and secondly they have inclines M2 by means of which the studs when
raised out of groove gl are pushed up into groove g.
According as the pieces M are moved nearer to or farther from the inclines L,
the studs will be sooner or later raised from the deeper to the shallower groove,
and the closing of the supply valve will consequently take place sooner or later.
This shifting of the pieces M is effected in the following manner. Each piece
carries a horizontal toothed rack Z, Z', which racks are arranged one behind the

page_text: other at right angles to the surface of the upper incline of the slide c The front
rack Zis, for a purpose to be presently described, shifted downwards relatively
to to the extent of the height of a tooth and with each one gears a toothed
pinion R R rotatable on an axis S S¹ fixed to the slide .
The pinion R is of such a width that a portion thereof comes in gear with
pinion R', while the other part is in gear with the rack. Z.
In order to prevent
rack Z' from also gearing with pinion R', the latter is shifted upward relatively
to R, so that it is partly covered by rack Z. Thus when the one piece M is
shifted, the above described gear causes the piece M' to be shifted in the contrary
direction, so that these pieces always occupy a symetrical position relatively to
each other. The adjustment of the said pieces is effected by hand by means of a
crank handle K fixed on the axis of one of the pinions RR.
The pieces M may be automatically adjusted by means of a stud N¹ of the
rack Z, which is acted upon by stops 0¹02 of a rod O moved by the engine
governor.
The racks Z Z are also provided with grooves N2 N2 into which take guide
rails P fixed to the slide c.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
―:
1. Valve gear for steam engines and similar motors wherein the rods e e¹ that
actuate the devices controlling the admission and discharge of the fluid pressure,
are provided with studs which are alternately made to gear with the one or
other of two grooves g g parallel to the cylinder formed in a slide e, which travels
longitudinally synchronously with the engine piston, and the said studs in being
made to pass from the one groove to the other by inclines brought in contact there-
with by the alternating motion of the slide, move the valve rods so as to alternately
open and close the valves, substantially as described.
2. In valve gear such as is referred to in the preceding claim, constructing the
one of the said grooves g g' deeper than the other, and causing the studs of the
valve rods e e¹ to enter them by spring or other pressure, the shifting of the studs
from the shallower to the deeper groove being effected by inclines or L, while the
shifting of the studs back from the deeper to the shallower groove is effected by
pieces M, m, having double inclines M² m², M² m², substantially as described.
3. In valve gear such as is referred to in the preceding claims, constructing the
pieces M with inclines M' M², that effect the cut off, adjustable in the groove of
the slide, and combining therewith toothed racks Z Z with which gear
pinions R R the one pinion R being made to gear partly with the rack Z and
partly with the pinion R, which only gears with rack 7', so that by the rotation of
the pinions or by the shifting of the one piece M, the other piece M¹ will be
shifted to precisely the same extent in the contrary direction, substantially as
described.
4. In valve gear such as is referred to in the preceding claims, the use of a stud
on the one toothed rack operating in combination with studs 0¹ (2 on a rod
operated by the governor, whereby the degree of cut-off can be automatically
varied according to the load on the engine, substantially as described.
Dated this 10th day of February 1891.
ABEL & IMRAY,
Agents for the Applicant.