VALVE GEAR FOR ENGINES
Year: 1885

page_text: I, CARL HARTUNG of Nordhausen in the Empire of Germany, Engineer, do
hereby declare the nature of my invention for "VALVE GEAR FOR
ENGINES" to be as follows:-
STEAM
This invention relates to expansion gear for slide or lift valves to steam engines
arranged and operating substantially as I will explain with reference to the
accompanying diagrams.
Fig. 1 shews the expansion gear actuated by a governor for non-reversible
engines. a is an eccentric driven by a way-shaft at the same speed as the engine;
its rod d is firstly connected to a rod e connected to the lever that actuates the
valve for admission of steam to the cylinder, and secondly the rod & is pivotted to
a pin on a block c sliding in a slot on a disc b, the axis of which is connected by
an arm and rod g to a governor, so that the motion of the latter will bring the
slotted disc from the position shewn in full lines to that shewn in dotted lines, or
any intermediate position.
When the engine is running at its lowest speed and the governor is in its lowest
position, the slot of the disc is in the horizontal position shewn, and the sliding
block c will consequently move to and fro horizontally with the motion of the
eccentric rod; the end k of the latter will consequently be actuated so as to cause
steam to be admitted to the cylinder during the whole of the stroke.
On the speed increasing, the governor will effect the turning of the slotted disc b
into an angular position more or less approaching that shewn in dotted lines, where-
upon, as the block c and with it the pin i on which the eccentric rod d is pivotted
will have a rising and falling motion in addition to its to and fro motion, the
movement of the end of the rod will be so modified as to cause the valve to close
and cut off the steam supply at a certain point of the stroke, the cut-off taking
place the sooner, the greater the angular position of the slot is.
Fig. 2 shews a diagram of a modified arrangement of the expansion gear as
applied to reversing engines. In this case the rod d of the eccentric a is pivotted
to a sliding block in a slotted disc & arranged and actuated in the same manner as
the well known "Hackworth" reversing gear, the end of the eccentric rod being
connected to rods e that actuate the levers of the steam and exhaust valves. The

page_text: eccentric a is further connected by a rod d¹ to a sliding block c in the slot of disc b,
which is the same as the disc b of the first arrangement. The block c is also
connected to a rod e¹, that is connected to a bell crank lever constituting the
fulcrum of the valve lever actuated by the rod e, so that according as the slot of
the disc b is moved into a more or less oblique position relatively to the motion of
the rod d¹, the fulcrum of the lever will be raised and lowered to a greater or less
extent, and the steam valve will consequently be made to close earlier or later.
The discs b and s are connected by an articulated rod h, so that, on reversing the
position of the latter by hand, the position of the former is also reversed.
Dated this 8th day of January 1885.
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,
London, W.C.

page_text: I, CARL HARTUNG, of Nordhausen in the Empire of 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 expansion gear for slide or lift valves to steam engines
arranged and operating substantially as I will explain with reference to the
accompanying diagrams.
Fig. 1 is an end view and Fig. 2 a side view of the expansion gear actuated by a
governor for non reversible engines. Figs. 3 and 4 shew diagrammatically the
acting parts of the gear. For each end of the cylinder these parts are as follow.
a is an eccentric driven by a counter-shaft at the same speed as the engine; its
rod d is firstly connected by a rod e to the lever that actuates the lift-valve for
admission of steam to the cylinder, and secondly the rod d is pivotted to a pin i on
a block c sliding in a slot on a disc b, the axis h of which is connected by an arm f
and rod g to the sliding collar of a governor, so that the motion of the latter will
bring the slotted disc from the position shewn in full lines wv to that shewn in
dotted lines m n (Fig. 4) or any intermediate position.
When the engine is running at its lowest speed and the governor collar is in its
lowest position, the slot of the disc is in a horizontal position wv and the sliding
block c consequently moves to and fro horizontally, or nearly so, with the motion
of eccentric rod; the end k of the latter is actuated so as to cause steam to be
admitted to the cylinder during the greater part of the stroke.
On the speed of the engine increasing the governor will cause the slotted disc b
to turn into an angular position more or less approaching m n Fig. 4, thus giving
the block c and with it the pin on which the eccentric rod d is pivotted_an
upward and downward motion in addition to its horizontal to and fro motion. The
movement of the end k of the eccentric rod is thus so modified as to cause the valve
to close and cut off the steam supply at an earlier part of the stroke, the cut-off
taking place sooner, the greater the obliquity of the slot. In the position m n steam
is quite cut off.
Fig. 5 represents a modified arrangement of which Fig. 6 is a diagram shewing
the expansion gear applied to a reversing engine. In this case also, the eccentric
rod is pivotted to a sliding block m¹ in a slotted disc 8 as in the known "Hack-
worth" reversing gear, and its end is connected to rods p p¹ that actuate the
levers of the steam and exhaust valves respectively. When the slot of 8 is in
the middle position xx¹, the steam valves are not opened. When it is in the
direction y y¹, the engine moves at full speed forwards; when it is in the direction z z¹,
the engine moves at full speed backwards. At intermediate positions the engine
receives more or less steam for movement forwards or backwards. The eccentric 8
is further connected by a rod o to a sliding block c in the slot of a disc b as in the
arrangement shewn in Fig. 1. The block c is also connected by a rod e¹ to one arm
of a bell crank lever c¹ the other arm a¹ of which forms a fulcrum for the valve

page_text: lever, so that according as the slot of the disc b is moved into a more or less
oblique position relatively to the motion of the rod o the fulcrum a¹ is raised and
lowered to a greater or less extent, and the steam valve is consequently made to
close at a different part of the stroke. The discs b and s are connected by a
jointed rod t, so that, on altering the position of s by the pull or push of the rod f¹,
the position of b is altered. In the middle position xx of the slot in 8, the slot in
b is in the line q q¹. When 8 is turned so that its slot takes the line y y' or z z¹,
the slot of b is brought into the liner. Thus, whether the engine is moving
forwards or backwards, the cut off is determined by the greater or less inclination
of the slot in b towards rr¹.
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
1. The valve gear for a steam engine substantially as described with reference to
Figs. 1, 2, 3 and 4 wherein the eccentric rod that works the steam valve is guided.
in transverse movement by a slot more or less inclined by the governor.
2. The valve gear for a reversible steam engine, substantially as described with
reference to Figs. 5 and 6, wherein the slot that guides the transverse movement of
the eccentric rod is more or less inclined by its connection to Hackworth reversing
gear.