Improvements in Valve Gear.
Year: 1891

page_text: Date of Application, 19th June 1891
Complete Specification Left, 14th Aug., 1891-Accepted, 19th Sept., 1891
PROVISIONAL STEIFICATION.
Improvements in Valve Gear.
We, ALBERT MARCELLO SYKES, Engineer, of 1418, Renwick Street,
Philadelphia, Pennsylvania, and CHARLES CONNELLIOUS WEBBER, Engineer,
of 922, Pine Street, Wilmington, New Castle County, Delaware, United States of
America, do hereby declare the nature of this invention to be as follows:-
The object of our invention is to provide a simple form of valve gear to take the
place of the ordinary link-motion in locomotives and stationary engines for the
purpose of reversing the stroke.
According to this invention, the slide valve rod is jointed to and reciprocated by
the upright arm of a double-elbow lever which is fulcrumed to the upper end of a
standard mounted upon guide bars in which slides the cross-head of the piston rod.
Upon each of the guide bars there is a short standard to which are respectively
jointed the ends of a pair of cam-arms whose pivots or axes are reversed or at
opposite ends to each other; their outer ends being guided upon stems and forced
downwardly by spiral springs. The cam-arms are respectively connected to one of
the arms of the double-elbow lever by links. The cross-head carries a lift-plate
which slides under and lifts one or the other of the cam-arms and transmits through
one or the other of the links an oscillating motion to the double-crank lever for
shifting the slide-valve in the normal operation of the engine.
In the operation of the engine the slide-valve is worked by only one of the cam-
arms and links, the others being thrown out of use and being brought into play
only when the engine is to be reversed. Thus one cam-arm is inclined downwardly
at its spring end so as to be acted upon by the lift-plate on the cross-head while the
other cam-arm is held in a horizontal position and is not lifted by the plate. In
this position of the valve-gear therefore, when the cross-head and piston moves in
one direction it lifts the inclined cam-arms and through its corresponding link throws
the arm of the elbow-lever so as to shift the valve and when the cross-head moves
in the other direction the spring forces the cam-arm and link down and moves the
valve back again to its former position.
Now it is obvious that as the cam-arms are pivoted at opposite ends they will act
reversely upon the valve when lifted by the lift-plate, and we will now describe the
means whereby the first-mentioned cam-arm is thrown out of action and the rear one
brought into action to reverse the stroke of the valve and piston. The links are
not connected directly to their respective arms of the elbow lever but are connected
to the opposite ends of a horizontal shifting bar whose ends embrace the arms of
the elbow lever. This shifting bar is thrown to the right or left by means of a hand
lever which is fulcrumed at its lower end to some stationary part and is slotted and
provided with a sliding box where it connects with the rectilinearly-sliding bar so
as to compensate for the difference between the curved movement of the lever and
the straight movement of the shifting bar. Now when the lever is thrown to the
right the upper ends of the two links are thrown to the right. The effect of this
is to throw the upper end of one link away from the centre of the elbow-lever and
throw the end of its cam-arm down into the inclined or operative position while the
other link lifts its cam arm into a horizontal position in which it is not acted upon
by the lift-plate on the cross-head. To reverse the engine, the lever is thrown to
the left. This causes the first link to lift its cam-arm to a horizontal position, in
which it is unacted upon, while the other link throws its cain-arm down into inclined
position, in which it receives the motion of the plate on the cross-head, and as this

page_text: cam-arm is reversed in its inclination from that of the other cam-arm it follows that
it imparts a reversed throw to the valve.
Dated June 19th 1891
COMPLETE SPECIFICATION.
Improvements in Valvė Gear.
We, ALBERT MARCELLO SYKES, Engineer, of 1418, Renwick Street,
Philadelphia, Pennsylvania, and CILARLES CONNELLIOUS WEBBER, Engineer,
of 922, Pine Street, Wilmington, New Castle County, Delaware, United States of
America; 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:-
gear to
The object of our invention is to provide a new and simple form of valve
take the place of the ordinary link-motion in locomotives and stationary engines for
the purpose of reversing the stroke; and it consists in the peculiar construction
and arrangement of parts which we will now proceed to fully describe with reference
to the accompanying drawings, forming part of this Specification, in which
Figure 1 is a side view of the valve gear shewn in one position in connection with
the piston and slide valve.
Figure 2 is a similar view shewing another position, and
Figure 3 is a plan view of the valve gear.
'
A represents an ordinary steam-cylinder, B its piston, and C its slide valve, the
latter playing over and alternately connecting one of the induction ports a a with the
exhaust port in the usual way. The slide valve is provided with a rod C¹ which
is jointed and reciprocated by the upright arm d of the double elbow leverede.
This double elbow lever is fulcrumed to the upper end of stationary fulcrum frame
or standard D which is mounted upon the guide bars E E in which slides the cross-
head Fattached to the piston rod G. Upon each of the guide bars E is mounted
a short standard and to which are respectively jointed the ends of cam arms gy
the pivot or axis of the arms being reversed or at opposite ends from each other.
The outer ends of these cam arms are guided upon stems h h and are forced
downwardly by spiral springs i. Near the spring i one of the cam arms is con-
nected to one arm e of the double elbow lever by a link h² and the other cam arm is
similarly connected by another link to the other arm c of the double elbow lever.
Attached to the cross-head and sliding under and lifting the cam arms is a lift
plate H which when the cross-head reciprocates lifts one or the other of the cam
arms and transmits through one or the other of the links an oscillating motion to
the double crank lever for shifting the slide valve in the normal operation of the
'engine.
In the operation of the engine the slide valve is worked by only one of the cam
arms and links, the others being thrown out of use and being brought into play only
when the engine is to be reversed. Thus, as shewn in Figure 1, the front cam arm y
is inclined downwardly at its spring end so as to be acted upon by the lift plate on
the cross-head while the other cam-arm is held in a horizontal position and is not
lifted by the plate. In this position of the valve-gear, therefore, when the cross-
head and piston move to the right, it lifts the cam arm g and through the link h
throws the arm d of the elbow-lever to the left to shift the valve and when the
cross-head moves to the left the spring i forces the cam arm g and link / down and
throws the elbow lever to the right, moving the valve back again to its former
position.

page_text: Now, it is obvious that as the cam arms are pivoted at opposite ends, they will
act reversely upon the valve when lifted by the lift plate and we will now describe
the means whereby the first-mentioned cam-arm is thrown out of action and the
rear one brought into action to reverse the stroke of the valve and piston. The
links h are not connected directly to their respective arms c and e of the elbow
lever but are connected (see Figure 3) to the opposite ends of a horizontal shifting
bar I whose ends embrace the arms ce of the elbow lever. This shifting bar I is
thrown to the right or left by means of a hand lever J which is fulcrumed at its
lower end to some stationary part and is slotted and provided with a sliding box
where it connects with the rectilinearly-sliding bar I so as to compensate for the
difference between the curved movement of the lever and the straight movement of
the shifting bar I. Now, when the lever J is thrown to the right, the upper ends
of the two links are thrown to the right. The effect of this is to throw the
upper end of link h away from the centre of the elbow-lever and throw the end of
its cam army down into the inclined or operative position while the link lifts its
cam arm into a horizontal position in which it is not acted upon by the lift plate
on the cross-head. To reverse the engine, the lever J is thrown to the left, as in
Figure 2 this causes the link to lift cam arm g to a horizontal position in which
it is unacted upon, while the other link throws its cam arm g' down into inclined
position in which it receives the motion of the plate on the cross-head and as this
cam arm is reversed in its inclination from that of g, it will be seen that it imparts
a reversed throw to the valve.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is-
1. A. valve gear consisting of a cross head carrying an actuating plate a pair of
reversely arranged cam arms pivoted at one end and maintained alternately in a
position to be acted upon by said plate and means for transmitting the motion of the
cam arms to the valve, substantially as shewn and described.
2. A valve gear consisting of a cross head carrying an actuating plate a pair of
cam arms and springs each arm being arranged to be brought alternately into or
out of engagement with the said plate a double elbow lever connected to the slide
valve and links connecting the double elbow lever to the cam arms, substantially as
shewn and described.
3. A valve gear consisting of a cross head bearing an actuating plate a pair of
cam arms pivoted at opposite ends and provided with springs for forcing them
downwardly a double elbow lever connected to the valve a shifting bar sliding on
the double elbow lever and connected to the cam arms by means of links and a
hand lever connected to the shifting bar, substantially as shewn and described.
2001
0
A. M. SYKES,
C. C. WEBBER,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.