Improvements in Automatic Valve Gear for Steam Engines.
Year: 1897

page_text: Date of Application, 17th Apr., 1897
Complete Specification Left, 11th Feb., 1898-Accepted, 16th Apr., 1898
PROVISIONAL SPECIFICATION.
Improvements in Automatic Valve Gear for Steam Engines.
I, RICHARD PARKIN, of 5, Bentinck Crescent, in the City and County of
Newcastle-upon-Tyne, Engineer, do hereby declare the nature of this invention to
be as follows:-
The objects of my invention are to simplify the construction and operation, to
reduce the cost, to give perfect control, instant automatic action and to economise
steam. The gear may be adapted to horizontal, diagonal or vertical engines but I
will describe it as horizontal.*
The improvements are applicable to many forms of steam engines but specially
to those used on board steamers for working steering and steam winch, or other
winding gear, and will preferably be applied to engines with compound cylinders
and I will describe it as so applied.
In order to get the full benefit of the expansive action of the very high pressure
steam now used in steam ships I apply a small high pressure cylinder with
"lap" on the valve to cut off the steam and a larger low pressure cylinder, with a
reservoir to receive the exhaust steam which, having operated in the latter cylinder,
is discharged into the condenser thus utilising the vacuum.
The cranks of the two cylinders are at right angles and each valve is worked by
a single eccentric immediately opposite the crank. The eccentric rods to which.
the valve rods are attached are connected with a block sliding in a slotted disc
which can be rotated to a certain extent on each side of its normal vertical position
so as to give the necessary "lead" to the valves to start the engine in either
direction.
This is effected by a pair of bevel wheels, one keyed on the steering wheel
shaft the other keyed on a vertical spindle the screwed end of which works in a
screwed nut in a worm wheel gearing into a worm on the crank shaft, which worm
also drives the chain barrel. The revolution of the steering wheel causes the
vertical screwed spindle to travel in the nut in the worm wheel, upward or down-
ward, and to rotate the slotted disc so as to start the engine in either direction and
the steering wheel, continuing to be rotated, prevents the valve closing by the
action of the worm wheel, which constantly tends to do so, and bring the engine
to rest but when the steering wheel is released the valve is instantly and automati-
cally closed by the action of the worm wheel which has hitherto been counteracted
by the steering wheel. When steering from the bridge the vertical screwed spindle
is revolved by a hand wheel, also revolving the pair of bevel wheels and the steering
wheel, and travelling upward or downward in the nut in the worm wheel so rotates
the slotted disc as to start the engine in either direction until the hand wheel is
released when the valve instantly and automatically closes by the action of the
worm wheel as previously described. Indexes will be provided to show the position
of the rudder to the man at the wheel and to the officer on the bridge. The gear
may be for power only or so fitted as to form a combined power and hand steering
engine.

page_text: As applied to steam winches, or similar purposes, the gear in its action is
similar, one eccentric only being required and the link motion being dispensed with.
The slotted disc is, in this modification, rotated by a lever handle by the man in
charge to the required angle so as to start the engine in either direction and con-
tinuing to hold the lever handle the engine operates until the load is at its proper
position when, the handle being moved into its neutral or central position, the
slotted disc through its sliding block and the eccentric rod closes the valve and
brings the engine to rest, or this action may be automatic by an arrangement of
worm or other gear upon the winch shaft which can be adjusted so as automatically
to close the valve at any required point of the travel of the load.
The valves may be of the ordinary form or may be piston valves to work without
friction and with compound cylinders the high pressure cylinder will exhaust
direct to the reservoir of the low pressure cylinder to avoid back pressure and so to
the distributing valve of that cylinder. Thus a separate automatic controlling
valve is dispensed with, the distributing valve fulfilling all requirements, riski
of leakage through an additional valve is avoided and the full work is got out of
the steam by expansion in the high pressure cylinder and from thence into the low
pressure cylinder as well as the benefit of the vacuum in the latter.
In any form of the application of these improvements to the various purposes to
which they are adapted although compound, or high and low pressure cylinders,
are preferable for obtaining the full value of the steam where high pressure steam
is used, two high pressure cylinders may be used for medium or comparatively low
pressures the disposition of the engine cranks and of the eccentrics relatively
thereto being as hereinbefore described.
Improvements in Automatic Valve Gear for Steam Engines.
I, RICHARD PARKIN, of 5, Bentinck Crescent, in the City and County of
Newcastle-upon-Tyne, 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:-
The objects of my invention are to simplify the construction and operation, to
reduce the cost, to give perfect control, instant automatic action and to economise
steam. The gear may be adapted to horizontal, diagonal or vertical engines but I
will describe it as horizontal."
The improvements are applicable to many forms of steam engines but specially
to those used on board steamers for working steering and steam winch, or other
winding gear, and will preferably be applied to engines with compound cylinders
and I will describe it as so applied.
steam now
"
In order to get the full benefit of the expansive action of the very high pressure
used in steam ships I apply a small high pressure cylinder with
'lap" on the valve to cut off the steam and a larger low pressure cylinder, with a
reservoir to receive the exhaust steam which, having operated in the latter cylinder
is discharged into the condenser thus utilising the vacuum.
Referring to the accompanying drawings Fig. 1 is an elevation and Fig. 2 a plan
of the apparatus,

page_text: The cranks A of the two cylinders A¹ and A2 are at right angles and each valve B
is worked by a single eccentric C immediately opposite the cranks A. The eccentric
rods D to which the valve rods E are attached are connected with blocks F sliding
in a slotted disc G which can be rotated to a certain extent on each side of the
normal vertical position so as to give the necessary "lead" to the valves B to
start the engine in either direction.
This is effected by a pair of bevil wheels H one keyed on the steering wheel
shaft J the other fixed into the neck of a worm wheel K gearing into a worm on
the crank shaft, which worm also drives the chain barrel. The revolution of the
steering wheel causes the vertical screwed spindle L to travel in the nut in the
worm wheel K upward or downward, and to rotate the slotted disc G so as to start
the engine in either direction and the steering wheel, continuing to be rotated,
prevents the valve closing by the action of the worm wheel, which constantly tends
to do so, and brings the engine to rest but when the steering wheel is released the
valve is instantly and automatically closed by the action of the worm wheel which
has hitherto been counteracted by the steering wheel. When steering from the
bridge the vertical screwed spindle L is revolved by the hand wheel, also revolving
the pair of bevil wheels H and the steering wheel, and travelling upward or down-
ward in the nut in the worm wheel so rotates the slotted disc G as to start the
engine in either direction until the hand wheel is released when the valve instantly
and automatically closes by the action of the worm wheel as previously described.
An Index M will be provided to show the position of the rudder to the man at
the wheel and to the officer on the bridge. The gear may be for power only or so
fitted as to form a combined power and hand steering engine.
As applied to steam winches, or similar purposes, the gear in its action is
similar, one eccentric only being required and link motion being dispensed with,
the valve worked by the eccentric acting as a reversing and starting valve, as
well as a cut off valve, without the use of a reversing link. The slotted disc is, in
this modification rotated by a lever handle by the man in charge to the required
angle so as to start the engine in either direction and continuing to hold the lever
handle the engine operates until the load is at its proper position when, the handle
being moved into its neutral or central position, the slotted disc through its sliding
block F and the eccentric rod closes the valve and brings the engine to rest, or this
action may be automatic by an arrangement of worm or other gear upon the winch
shaft which can be adjusted so as automatically to close the valve at any required
point of the travel of the load.
The valves may be of the ordinary form or may be piston valves to work without
friction and with compound cylinders the high pressure cylinder A¹ will exhaust
direct to the reservoir of the low pressure cylinder A³ to avoid back pressure and so
to the distributing valve B of that cylinder. Thus a separate automatic controlling
valve is dispensed with, the distributing valve B fulfilling all requirements, risk of
leakage through an additional valve is avoided and the full work is got out of the
steam by expansion in the high pressure cylinder A¹ and from thence into the low
pressure cylinder A2 as well as the benefit of the vacuum in the latter.
In any form of the application of these improvements to the various purposes to
which they are adapted although compound, or high and low pressure cylinders,
are preferable for obtaining the full value of the steam where high pressure steam
is used, two high pressure cylinders may be used for medium or comparatively low
pressures the disposition of the engine cranks and of the eccentrics relatively
thereto being as hereinbefore described.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
The construction, arrangement and combination of parts of the automatic valvo

page_text: gear for steam engines, especially with compound cylinders, for working steering,
steam winch, or other winding gear, substantially as described in the foregoing
Specification and shewn by the drawings.