IMPROVED VALVE GEAR FOR DIRECT ACTING ENGINES
Year: 1885

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I ALFRED JAMES BICKMORE of Walter Alfred Barlow's Patent Agency
6 St. Pauls Churchyard in the city of London do hereby declare the nature of
the said invention for IMPROVED VALVE GEAR FOR DIRECT ACTING ENGINES
a communication to me from abroad by William Voit, Engineer of Magdeburg in
the Kingdom of Prussia to be as follows:-
This invention relates to the construction of an externally placed valve gear,
which can easily be adjusted and adapted to the different degrees of tension of
steam.
The reciprocating motion of the piston-rod is to be transmitted to the rod of an
auxiliary slide-valve in such manner that the latter moves in a direction opposite
that of the piston rod.
As the stroke of the small slide-valve compared with that of the piston is
proportionally a very short one, and as the reversing must take place only when
the piston is approaching to the end of its stroke the construction hereinafter
described is employed.
A coupling K is secured to the piston rod This coupling gives the bar S³ fixed
to the axis S2 an oscillating motion by means of a socket H which is movable in
a piece M secured by two countersunk screws to the coupling K and takes the
bar S3 along with it, the latter thereby slides to and fro in the socket H. In con-
sequence of the oscillating motion of the bar S³ the axis S2 also receives an
oscillating motion which is transmitted to the tappets P and these latter move
the regulating rings Q to and fro and consequently also the auxiliary slide valve.
The steam piston (Fig. 1) moves in the direction of the arrow and the auxiliary
slide-valve in the position shewn in the drawing is just beginning to open the
steam port whereupon the distributing piston is moved to the other side and
the steam allowed to enter behind the steam piston.
The port g must suddenly be opened and the motion of the regulating rings Q
therefor be an accelerated one. The shape and disposition of the tappet P is very
important for obtaining this accelerated motion as they move on the regulating
pieces Q from below to the top. The revolution of the axis S2 is so much slower
in proportion to the distance traversed by the piston, the more nearly the piston
and consequently also the coupling attached to it approaches to the end of the
stroke. At the moment where a quick revolution of the axis S2 and consequently
a quick displacement of the pieces Q and of the auxiliary slide-valve should take
place, the contrary motion occurs.
This inconvenience will be met by the following construction.
To the lower end of bar S3 is fixed a screw nut a provided with a washer y.
When the piston now moves a little more to the left than shown in the drawing
(Fig. 1) the socket H will strike against the washer y. The socket H and the

page_text: bar S3 are stopped in their reciprocal motion and are caused to rise together in the
slit W into which catches the peg z fixed to the socket. The angular motion of S
and the rotation of the tappet P and likewise the displacement of the auxiliary
slide-valve will thereby increase and be accelerated.
The gearing can be adjusted in two different manners, first by displacing the
pieces on the auxiliary valve rod and secondly by displacing the nut a respec-
tively by employing a thicker or thinner washer y. The greater the distance
between the two pieces Q from each other the sooner the port g will be opened.
The higher the nut is screwed up on the bar S3 and also the thicker the washer
is the soon the socket H will strike against, and the sooner the quick motion of the
auxiliary slide valve will take place. The two pieces fixed by set screws may
be replaced by on piece of double width when the gearing has definitely been
adjusted.
Figs. 3 and 4 of the annexed drawing show the construction of the coupling K
for large engines. The peg of the socket H is here lodged in a block G sliding in
the slit.
If the auxiliary valve rod is required to move in the same direction as the piston
rod, the construction shown in the figures 5 and 6 must be chosen. The axis S³
with the tappet P is arranged above the auxiliary valve rod by which arrangement
the valve rod is moyed in the same direction as the piston rod.
Figs. 7 and 8 show a modification of the construction shown in the Figs. 1 and 2.
The socket H is cast in one piece with the axis S² and the tappet P attached to the
axis S2 in the same manner as formerly.
In this arrangement the socket H alone turns and does not get out of its place
but the bar S³ now rises in the slit of the coupling K as soon as the nut x with the
washer ย strikes against the socket H (see fig. 1).
In many cases where it is desirable to suppress the slit, the arrangement shown
in Figs. 9 10 and 11 may advantageously be applied. In Fig. 10 the peg z is cast
in one piece with the socket turning upon z and in Fig. 11 the peg is screwed in
the coupling K, the socket is here correspondingly bored out.
WALTER A. BARLOW,
6, St. Paul's Churchyard, E.C.,
Agent for Alfred James Bickmore.

page_text: The reciprocating motion of the piston rod is to be transmitted to the rod of an
auxiliary slide valve in such manner that the latter moves in a direction opposite
that of the piston rod.
As the stroke of the small slide valve compared with that of the piston is
proportionally a very short one and as the reversing must take place only when
the piston is approaching to the end of its stroke the construction hereinafter
described is employed and in order that the same may be well understood I have
hereunto annexed two sheets of drawings.
•
A coupling K is secured to the piston rod. This coupling gives the bar S³ fixed
to the axis S² an oscillating motion by means of a socket H which is movable in a
piece M secured by two countersunk screws to the coupling K, and takes the bar S³
along with it and said bars S³ thereby slides to and fro in the socket H. In con-
sequence of the oscillating motion of the bar S³ the axis S2 also receives an
oscillating motion which is transmitted to the tappets P and these latter move the
regulating rings to and fro and consequently also the auxiliary slide valve.
The steam piston (Fig. 1) moves in the direction of the arrow and the auxiliary
slide valve in the position shown in that drawing is just beginning to open the
steam port whereupon the distributing piston is moved to the other side and
the steam allowed to enter behind the steam piston. The port g must suddenly be
opened and the motion of the regulating rings Q therefore be an accelerated one.
The shape and disposition of the tappet P is very important for obtaining this
accelerated motion as they move on the regulating pieces Q from below to the top.
The revolution of the axis S2 is so much slower in proportion to the distance
traversed by the piston, the more nearly the piston and consequently also the
coupling attached to it, approaches to the end of the stroke. At the moment
where a quick revolution of the axis S2 and consequently a quick displacement of
the pieces Qand of the auxiliary slide-valve should take place the contrary motion
occurs.
This inconvenience will be met by the following construction.
To the lower end of the bar S2 is fixed a screw nut x provided with a
washer y.
When the piston now moves a little more to the left than shewn in the drawing
(Fig. 1) the socket H will strike against the washer 3. The socket H and the
bar S3 are stopped in their reciprocal motion and are caused to rise together in
the slot W into which catches the stud z fixed to the socket H. The angular
motion of S and the rotation of the tappet P and likewise the displacement of the
auxiliary slide valve will thereby increase and be accelerated.
The gearing can be adjusted in two different manners, first by displacing the
pieces on the auxiliary valve rod and secondly by displacing the nut. x respec-
tively by employing a thicker or thinner washer y.
The greater the distance between the two pieces Q from each other the sooner
the port g will be opened. The higher the nut a is screwed up on the bar S³ and
also the thicker the washer is the sooner the socket H will strike against, and the
sooner the quick motion of the auxiliary slide valve will take place. The two
pieces Qfixed by set screws may be replaced by one piece of double width when
the gearing has definitely been adjusted.
Figs. 3 and 4 of the annexed drawings show the construction of the coupling K
for large engines. The stud z of the socket H is here carried in a block G sliding
in the slot W. If the auxiliary valve rod is required to move in the same
direction as the piston rod the construction shown in the Figures 5 and 6 must be
chosen. The axis S² with the tappet P is arranged above the auxiliary valve rod
by which arrangement the valve rod is moved in the same direction as the
piston rod.
Figs. 7 and 8 shew a modification of the construction shewn in the Figures
1 and 2.
The socket His cast in one piece with the axis S² and the tappet P attached to
the axis S in the same manner as formerly.

page_text: In this arrangement the socket H rocks only and does not slide but the bar S³
now rises in the slot W of the coupling K as soon as the nut with the washer y
strikes against the socket H.
In many cases where it is desirable to suppress the slot W, the arrangement
shewn in Figs. 9. 10 and 11 may advantageously be applied. In Fig. 10 the
stud is cast in one piece with the socket H. which turns upon z and in Fig. 11
the stud is screwed into the coupling K, the socket H being correspondingly
bored out so that it may turn thereon.
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 is
Firstly. A valve gear for high pressure and compound engines consisting of the
arrangement of the bar S³ sitting with the tappets P on the same axis S² and
coupled by means of the socket H and coupling K with the piston rod so that when
the latter is in motion the bar S³ will oscillate about the axis S2 and thereby the
valve rod be moved by the tappet P striking against the regulating pieces Q secured
to the valve rod constructed and operating as set forth.
Secondly. In the valve gear as herein described the arrangement of an oblong
slot in the coupling K for the purpose of receiving or accomodating the stud z of
the socket H in order to give the bar S3 and consequently the auxiliary valve also
an accelerated motion when the stroke of the piston rod is approaching to its end
as set forth.
Thirdly. In the above described and claimed gear the contrivance for regulating
the same consisting of the arrangement of the nut x with washer y movable on the
bar S3 as set forth.
Fourthly. The modification of the construction mentioned in heads of claims
12 and 3 consisting of the connection of the socket H with the axis S2 and the
slide of the bar S3 by its top end provided with the nut and washer y in the said
socket as set forth."
Fifthly. The further modification of the said construction consisting of the
suppression of the slot in the coupling K and consequently also of the nut x and
washer y as herein specified.