IMPROVEMENTS IN WORKING VALVES OF STEAM AND OTHER ENGINES." PROVISIONAL SPECIFICATION.
Year: 1868

page_text: LETTERS PATENT to Alfred Willmer Pocock, of Pimlico, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN
WORKING VALVES OF STEAM AND OTHER ENGINES."
PROVISIONAL SPECIFICATION. left, by the said. Alfred Willmer Pocock
at the Office of the Commissioners of Patents, with his Petition,
on the 25th. April 1868.
I, ALFRED WILLMER POCOCK, of Pimlico, in the County of Middlesex,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN WORKING VALVES OF STEAM AND OTHER ENGINES," to be as follows:-
I cause the piston rod of the engine to which my Invention is applied,.
or some moving part connected with the piston, to put in operation some
power sufficient to give the valve the required movement. This power
may be a spring, or a weight, or the pressure of fluid on a piston,
which can only move the valve when released at a suitable point of
the stroke of the piston or moving part connected therewith. Such
moving part is provided with a suitable stop, incline, cam, eccentric,
or indent, which holds the valve in its place until the proper part of

page_text: the stroke is reached, and which then releases it and thus allows the
spring, weight, or piston acted on by fluid pressure to give the valve its
movement.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alfred Willmer Pocock in the Great Seal Patent
Office on the 23rd October 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
WILLMER Pococк, of Pimlico, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of April, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alfred Willmer Pocock, Her special
licence that I, the said Alfred Willmer Pocock, my executors, adminis-
trators, and assigns, or such others as I, the said Alfred Willmer
Pocock, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN WORKING VALVES OF STEAM AND OTHER ENGINES," upon
the condition (amongst others) that I, the said Alfred William Pocock,
my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months' next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Alfred Willmer Pocock, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement:-
The piston rod of the engine or some moving part connected with
the piston I connect with any available power sufficient when put in

page_text: operation to give the required movement to the valve. This power may
be a spring or a weight, or the pressure of fluid on a piston, which can
only move the valve at a suitable point of the stroke of the piston or
moving part connected therewith, which moving part is provided with
one or more suitable stops, inclines, cams, or indents for holding the
valve in its place until the proper part of the stroke is reached, then
releasing it, and thus allowing the spring, weight, or piston acted on by
the fluid pressure to give the valve its movement.
As this Invention will be more readily understood by reference to the
Drawings which accompany this Specification, I will at once proceed to
These Drawings are shewn in three divisions, marked "Plate I.",
"Plate II.", and "Plate III." respectively. In all like letters denote
like parts.
In Plate I. Fig. I. is a plan, .Fig. II. a half section and a half clevation,
and Fig. III. is a half transverse section and a half transverse elevation,
shewing one method of carrying out my Invention. A is the piston rod;
A' is the moving part in connection with the piston which by means
of the wedge-shaped portions of it, marked B, (and which portions may
be on the piston rod if more convenient,) puts in operation the power
required for moving the valve, which in this case is shewn as being
supplied by the pressure of a fluid on a piston; D, D, are the stops for
holding the valve in its position, which might also if convenient be
formed on the piston rod, thus obviating the necessity for this separate
moving part, and which release the valve at the suitable point of the
stroke of the piston; O is the valve spindle, which is expanded in the
instances here shewn into the oblong frame E, in the sides of which
are cut slots for pins to work in (rollers being shewn on these pins to
lessen friction), which pins transmit to the valve spindle the power put
into operation for its movement. It is not always necessary to form this
frame on the end of the valve spindle, for sometimes it may be more
convenient to form it on the piston rod or the moving part in connection
with the piston.) In this frame are fastened the stops F, F; H, H, are
two chambers having the two pistons G, G', fitted into them; in these
chambers is always maintained (when the engine is at work) a pressure

page_text: of fluid by such means as connecting them with a tube to the boiler in
the case of a steam engine, or to the main in case of a water engine,
this pressure is therefore always tending to force 'the pistons out of the
chambers; J and J' conjunctively denote cranked levers, two in number,
(K. denoting their fulcra); the arms J', J¹, rest on the pistons; the other
arms J, J, (being split for convenience) are forced by the pistons against
the pins L, L.
In Plate II. Figs. 1, 2, and 3 are respectively a plan, section, and
elevation of another method of carrying out my Invention. In this
instance I have shewn how springs may be employed for the movement
of the valve. Here A³, being the moving part which is to put the power
for moving the valve into operation, has an alternate circular motion
imparted to it by the piston rod and moves upon the centres M; B, B,
are two cams formed upon it; G, G, are two springs (in this case shewn
as india-rubber) which are stretched over the two pins L, L.
.
In Plate III. Figs. 1, 2, and 3, shew respectively an elevation, section,
and plan of a third method of carrying out my Invention. A¹ is the
moving part which is to put into operation the power for moving the
valve, which in this case I have shewn as supplied by two weights G, G¹;
this part A*, instead of being provided, as in the other two cases, with cams
or wedges, is made to revolve excentrically upon the centres (M, M,) and
is connected to the piston by means of the rack A formed on the end of
the piston rod which gears into a cog wheel fastened to the part A'; this
part being in this instance placed half on either side of it for the sake of
symmetry. In each of the cases illustrated by the Drawings the valve
is supposed to have just moved, and the arrows on the valve spindle
show the direction of its next movement. Now, supposing that the
pistons are moving in the direction indicated by the arrows on the piston
rods, the action will be as follows:-As soon as by its motion the piston
rod causes the part A¹to move the stop D will be brought in line with
the stop F in the direction of its movement. Then the wedge piece B, B,
in Plate I., the cams B, B, in Plate II., or the eccentric motion of A' in
Plate III., force in a direction similar to that of the next movement of the
valve the pins L, L; thus in Plate I. forcing down the piston G', in
Plate II. extending the springs G, G, and in Plate III. raising the
weight G³, and so putting into operation the power for the movement
of the valve and causing its motion at the suitable point of the stroke
when released by the stop D being brought out of line with the stop F.

page_text: Having now particularly described and ascertained the nature of the
said Invention, and in what manner the same is to be performed or
put in practice, I hereby declare that I do not claim the constituent
mechanical details of the constructions for working valves herein-before
described and illustrated by the Drawings when the same are considered
per se and apart from the object of my Invention, as so considered they
do not constitute the same; what I claim being the Invention herein-
before described and illustrated by the Drawings accompanying this
Specification.
In witness whereof, I, the said Alfred Willmer Pocock, have
hereunto set my hand and seal, this Twenty-first day of October,
in the year of our Lord, One thousand eight hundred and
sixty-eight.
Witness,
RP. COCKER.
ALFP. WILLMER POCOCK. (L.S.)