IMPROVEMENTS IN VALVES
Year: 1875

page_text: LETTERS PATENT to Robert Harlow, of Heaton Norris, Stockport,
in the County of Cheshire, for the Invention of "IMPROVEMENTS
IN VALVES."-A communication from abroad by Thomas Shaw, of
Philadelphia, Pennsylvania, United States of America.
PROVISIONAL SPECIFICATION left by the said Robert Harlow at the
Office of the Commissioners of Patents, with his Petition, on the
2nd October 1875.
I, ROBERT HARLOW, of Heaton Norris, Stockport, in the County of
Cheshire, do hereby declare the nature of the said Invention for "Ix.
PROVEMENTS IN VALVES," a communication to me from abroad by Thomas
Shaw, of Philadelphia, Pennsylvania, United States of America, to be as
follows:-
This Invention consists in the construction of a valve with a plunger
or piston head projecting from its seat for the purpose and in manner
hcreafter described, and in the provision of a hydraulic packing above

page_text: the top of the valve; the object of the Invention being to enable a
rapid stroke of the valve under high pressures without danger from
pounding or injuring the seat of the valve.
The valve has a lengthened stroke during its operation as it is
required to make a stroke equal to the length of the plunger or piston
head before any fluid, air, or steam passes the seat, and on its return
stroke it is held momentarily suspended by the liquid, air, or steam,
which only allows the valve to close gently its seat more or less rapidly
in proportion to the escape of the fluid, air, or steam, around the piston
head. There being always a small portion of the flùid, air, or steam
imprisoned in all the area of the valve seat for the distance equalizing
the length of the stroke of the piston, and this can only escape by the
slow leakage around the piston head, which thus makes a return stroke
before the valve reaches its seat, thus making a tight packing or joint
by the imprisoned fluid, air, or steam, whilst a rubber or gum disc fitted:
above the valve makes a tight joint when the valve is finally brought to
its seat. It is evident this method of cushioning can be employed in
the up
stroke as well as the down, as that the shape of the valvo may be
modified without altering the results.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 2
filed by the said Robert Harlow in the Great Seal Patent Office on
the 1st April 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
HARLOW, of Heaton Norris, Stockport, in the County of Cheshire, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of October, in the year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Robert Harlow, Her special g
licence that I, the said Robert Harlow, my executors, administrators,
and assigns, or such others as I, the said Robert Harlow, my
executors, administrators, and assigns, should at any agree with,
and no others, from time to time, and at all times thereafter during

page_text: 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 VALVES," a communication to me from abroad by
3 Thomas Shaw, of Philadelphia, Pennsylvania, United States of America,
upon the condition (amongst others) that I, the said Robert Harlow,
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
immediatly after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Robert Harlow, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
-
The object of this Invention is to construct a valve which shall
obviate the hammering usual to check or back pressure valves, and
which shall almost be noiseless in its action. Now this Invention
consists in combining a disc, mushroom, conical, or other suitable form
of valve with a piston or plunger in such a manner that a small
quantity of liquid, air, or steam becomes momentarily trapped during
the downward stroke of the valve, and forms a cushion to prevent the
valve coming in immediate contact with its metallic seating.
In order that this Invention may be the more readily seen and under-
stood, I have hereunto annexed a Drawing illustrating two modifications
of the Invention.
Fig. 1 represents a sectional view of a valve box, and Fig. 2 a
sectional view of a back pressure valve, both having the improvements
applied thereto. In both the views, A is the inlet end, and B the
outlet end of the valve box, which in Fig. 1 is bolted together in two
parts, as illustrated by the bolts 0; D is the valve seating, and E the
valve, which is constructed with a piston head F fitting into a corre-
sponding shaped cylindrical cavity G (see Fig. 2) formed above the
valve seating, and the lower extremity of the valve E terminates in a
short piston H (corresponding in length to the piston head), from which
the ordinary guiding wings I depond. This latter piston is designed to

page_text: fill up the entire opening leading from. the inlet end A. to the valve
seating, whilst the valve E is approaching its seat, and thus meanwhile
to trap a little of the liquid, air, or steam between such valve and its
scating, in order to prevent the hammering action incidental to this
description of valve, and at the same time rendering the action of the 5
valve almost noiseless.
In the case of the valve box seen in Fig. 1; J is a piston or plunger
which by entering the corresponding shaped cavity K. formed in the
valve E so obviates the hammering action of the valve and renders it
noiseless in its upward stroke. It will thus be seen that in this 1
construction of valve box the valve has a lengthened stroke during its
operation, as it is required to made a stroke equal to the length of the
plunger or piston head before any fluid, air, or steam passes the seat,
and on its return stroke it is held momentarily suspended by the liquid,
air, or steam, which only allows the valve to close gently to its seat 1
more or less rapidly in proportion to the escape of the liquid, air, or
steam around the piston head, there being always a small portion of the
liquid, air, or steam imprisoned in all the area of the valve seat for the
distance equalizing the length of the stroke of the piston. It is evident
this method of cushioning can be employed in the up stroke as well as
the down, and that the shape of the valve may be modified without
altering the results.
I claim the method of cushioning check and other similar valves as
and for the purposes described and illustrated on the accompanying
Drawing.
In witness whereof, I, the said Robert Harlow, have hereunto
set my hand and seal, this 31st day of March, 1876.
ROBT. HARLOW. (L.S.)