IMPROVEMENTS IN MECHANISM OR APPLIANCES FOR STEADYING, CONTROLING, OR BUFFERING VALVES OF AIR ENGINES AND OTHER MECHANISM LIABLE TO SUDDEN SHOCKS,
Year: 1882

page_text: LETTERS PATENT to John Scarisbrick Walker, Thomas Ascroft Walker and
Edwin Robert Walker all of the Pagefield Ironworks Wigan in the County
of Lancaster, for an invention of "IMPROVEMENTS IN MECHANISM OR APPLIANCES
FOR STEADYING, CONTROLING, OR BUFFERING VALVES OF AIR ENGINES AND
OTHER MECHANISM LIABLE TO SUDDEN SHOCKS,
PROVISIONAL SPECIFICATION left by the said John Scarisbrick Walker,
Thomas Ascroft Walker & Edwin Robert Walker at the Office of the
Commissioners of Patents on the 30th March 1882.
JOHN SCARISBRICK WALKER THOMAS ASCROFT WALKER and EDWIN ROBERT
WALKER all of the Pagefield Ironworks Wigan in the County of Lancaster.
"IMPROVEMENTS IN MECHANISM OR APPLIANCES FOR STEADYING CONTROLING OR
BUFFERING VALVES OF AIR ENGINES AND OTHER MECHANISM LIABLE TO SUDDEN
SHOCKS
"
This invention is designed to prevent the dancing jarring knocking and
consequent wear tear and leakage incidental to valves required to be opened and
closed quickly and at brief intervals of time.
We have found that the desiderata in this case are 1st that the valves shall be
steadied without too great friction. 2nd that their velocity of movement shall be
gradually but rapidly lessened towards the end of stroke while allowed freely to
work near the middle of the stroke. 3rd that immediately before the actual point
of contact a very strong buffering action should take place to prevent the blow
of metal on metal. 4th that these actions should be suceptible of regulation or
adjustment to provide for wear and for differences of speed in the machinery.
All of these we have endeavoured to fully provide for in this our invention.
It consists in a fluid regulator acting on the valve spindle or piston of same
preferably in conjunction with stationary india-rubber buffers against which
collars on the valve spindle or projections on the valve strike at one or both ends
of the stroke.

page_text: There are numerous ways of arranging this fluid meter, and the fluid employed.
can be mercury, oil, soapy or alkaline water, or even in some circumstances it can
be gaseous; a very convenient form is to pass the valve spindle through a cylinder
with a piston attached to the valve spindle working therein: though the valve
spindle need not necessarily pass through the cylinder but may be attached to
piston at one end This cylinder is preferably formed with a larger internal
diameter in the centre than at each end or what is equivalent with wider channels
for the leakage past the piston in the mid portion of the stroke than at the ends.
From each end of the cylinder a pipe or passage leads to accumulators as hereafter
described or to a junction provided with a valve or stop cock. This valve or cock
if fully opened allows almost free and unlimited circulation from one end of the
cylinder to the other, but can be throttled to any desired extent or be entirely
closed it can be worked by hand or by the engine valve apparatus or both and
be regularly and constantly worked or adjusted as required. We sometimes
have a passage through the piston of convenient diameter to form a communication
from one side to the other to prevent any possibility of the piston sticking.
Where the cock or valve is worked by the engine valve gear the cylinder can
have a true cylindrical internal form, but even in such case we prefer it with a
greater internal diameter in the centre than at the ends somewhat of the shape of
a bulge barrel in fact. In place of a stop cock between the two ends or in
combination with the same we sometimes place in connection with each end of the
small cylinder an accumulator preferably in stable equilibrium, that is with its
weight resting on a seat but so that any addition to the water or other liquid
below it will lift it from its seat or lift a part and each addition to the water or
other liquid lift à further part or we place an air chamber as in pumps the air in
which, by compression gives an increase of pressure or in place of the accumulator
a head of water or other liquid and air chamber for compression can be used, the
main point being to cause as little resistance as possible in the middle of the stroke
and gradually increase the resistance at each end. The accumulator with weights
resting on seats might be used to effect the buffering but we prefer to do this
with india rubber buffers which can be adjusted in wear so as to come into
action only at the very end of the stroke and break the force of a sudden blow.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Scarisbrick Walker, Thomas Ascroft Walker, & Edwin
Robert Walker in the Great Seal Patent Office on the 30th September 1882.
JOHN SCARISBRICK WALKER, THOMAS ASCROFT WALKER, and EDWIN ROBERT
WALKER, all of the Pagefield Iron Works, Wigan in the County of Lancaster
"IMPROVEMENTS IN MECHANISM OR APPLIANCES FOR STEADYING CONTROLLING OR
BUFFERING VALVES OF AIR ENGINES AND OTHER MECHANISM LIABLE TO SUDDEN
SHOCKS,"
This invention is designed to prevent the dancing jarring knocking and
consequent wear tear and leakage incidental to valves required to be opened and
closed quickly and at brief intervals of time.
We have found that the desiderata in this case are 1st that the valves shall be
steadied without too great friction. 2nd that their velocity of movement shall be
gradually but rapidly lessened towards the end of stroke while allowed freely to
work near the middle of the stroke, 3rd that immediately before the actual
point of contact a very strong buffering action should take place to prevent the
blow of metal on metal. 4th that these actions should be susceptible of regulation
or adjustment to provide for wear and for differences of speed in the machinery.
All of these we have endeavoured to fully provide for in this our invention.
It consists in a fluid regulator acting on the valve spindle or piston of same
preferably in conjunction with stationary or movable india rubber buffers against
which collars on the valve spindle or projections on the valve strike at one or both
ends of the stroke.
Referring to the annexed drawings of apparatus in the most approved form now
manufactured by us;
Fig 1 is a general sectional view of controlling apparatus, Fig: 2, plan,
Figs: 3 and 4, enlarged views of parts of fig: 1.
Fig 5, a modified buffering apparatus applied
:
either inlet or outlet valves.
Like figures relate to like parts in all the drawings.
In these A is tho valve admitting air into the cylinder, B is the exit valve.
These are made in accordance with our former patent so as to leave as little dead
space as possible. Referring especially to the exit valve and fig: 3 C is a cylinder
a little greater in diameter at the centre than at the ends containing a piston. D,
and filled with a suitable fluid such as oil mercury glycerine or soapy water or in
some circumstances it can be gaseous. E piston rod attached to valve spindle F and
by it to link G. H H are valves weighted with springs adjusted by set screws (not
shown in the drawing) I passage for the fluid to go from end to end of the cylinder
when the valves are open. J regulating cock allowing free passage when open but
capable of being closed to any desired extent so as to regulate the passage.
K passage through piston. L L two caps carrying spring M between them and the
latter screwed upon spindle F. N buffer of india rubber to prevent the two
surfaces of metal knocking together.
The valve spindle F passes through the cylinder C the piston D which works
therein being attached to the spindle F. The cylinder C is filled with a suitable
fluid or gas and as the valve spindle moves to and fro this fluid or gas passes by
suitable passage I from one end of the cylinder to the other. This may be a
simple passage merely connecting the two ends of the cylinder or there may be
weighted or other valves placed in it to regulate and control the flow of the fluid.

page_text: Hare weighted valves placed at either end of the passage I to maintain a pressure
on the fluid in the cylinder. Instead of the weighted valves H in the passage the
pipes from each end of the cylinder may lead to an hydraulic accumulator
preferably in a state of stable equilibrium that is with its weight resting on a
seat but so that any addition to the water or other liquid below it will lift it from
its seat or lift a part of it and each addition to the liquid lift a further part or
instead of an accumulator. the pipe from the cylinder ends may lead to an air
chamber such as is used in force pumps the air in which by compression gives an
increase of pressure. Or a head of water or other liquid may be used to give the
required amount of pressure. The amount of the liquid passing through the
passage I is controlled and regulated by a tap or cock J of ordinary construction.
This valve or cock if fully opened allows almost free and unlimited circulation
from one end of the cylinder to the other but can be throttled to any desired extent
or be entirely closed. It can be worked by hand or by the engine valve apparatus
or both and be regularly and constantly worked or adjusted as may be required in
accordance with the varying speed or other conditions under which the engine
may be working. The cylinder C is preferably formed with a larger internal
diameter in the centre than at each end as shown at c in the drawings in order
that at the centre of the stroke little or no resistance shall be placed on the free
travel of the valve spindle. Where the cock or valve J is worked by the engine
valve gear the cylinder can have a true cylindrical internal form as the cock will
provide for a free passage of the fluid when the piston is at the centre of its stroke.
One or more passages K through the piston of convenient diameter form a
communication from one side to the other and prevent any possibility of its
sticking in the cylinder at the end of the stroke.
To prevent the striking of metal against metal We insert buffers of india
rubber N. between the nut n on the valve spindle and the top of the stuffing box
of the valve though the accumulator could be so arranged as to perform the same.
A modification of the arrangement is shewn in Fig: 5 where the india rubber
buffers N are attached to a cross bar N¹ fixed on the valve spindle and the buffering
is effected between the bar N¹ and the nuts n¹.
$
It will be evident that though we have throughout our Specification referred
only to a cylinder and piston as a means of steadying the valve in conjunction
with buffering apparatus it is obvious that nearly the same effect could be obtained
by their mechanical equivalent a rectangular or polygonal chest and flexible
diaphragm. Flexible diaphragms are however very apt to wear out or leak and
are not nearly as good as a solid or perforated piston and we therefore only
mention this mechanical equivalent to prevent others claiming or adopting the
same for the purpose of getting round our patent. Similarly we do not bind
ourselves to the exact arrangement.
We claim as our invention to be protected under Letters Patent:-
1st. The improvement, in mechanism or appliances for steadying, controlling or
buffering valves of air engines and other mechanism liable to sudden shocks which
consists in the combination of a piston rod of a piston or diaphragm linked, or
otherwise attached, to the valve or other mechanism liable to sudden shocks and
working a cylinder or its equivalent containing said piston or diaphragm and
having a passage or passages for the limited flow of the liquid contained in
the cylinder or its equivalent from one side the said diaphragm or piston to the
other.
2nd. In combination with a cylinder and piston forming a steadying or
controlling apparatus for valves or other mechanism liable to sudden shocks any of
the following; a controlling cock or valve capable of shutting off or adjusting a
part of the flow; the enlargement of the diameter of the central portion of the
cylinder so as to increase the area of escape during the central portion of the
stroke; the passage through the cylinder. All substantially as and for the purpose
described.

page_text: 3rd. In combination with a pneumatic or hydraulic cylinder for steadying or
controlling the valve the india rubber buffers whether fixed or movable for bringing
the valve or other apparatus requiring checking to rest very rapidly at the ends
of the stroke.
In witness whereof I the said Thomas Ascroft Walker for and on behalf of
myself and the said John Scarisbrick Walker and Edwin Robert Walker'
have hereunto set my hand and seal this Twenty seventh day of September
in the year of our Lord one thousand eight hundred and eighty two.
THOMAS ASCROFT WALKER. (L.S.)