Improvements in Duplex Direct-acting Steam and other Pumps and Engines.
Year: 1890

page_text: Date of Application, 19th July, 1890
Complete Specification Left, 18th Apr., 1891-Accepted, 11th July, 1891
PROVISIONAL SPECIFICATION.
Improvements in Duplex Direct-acting Steam and other Pumps and
Engines.
We GEORGE GORDON PICKING and WILLIAM HOPKINS both of 58 Bow Road
Bow in the County of Middlesex Engineers do hereby declare the nature of this
invention to be as follows:-
This invention relates to improvements in the cylinders of duplex direct-acting
steam and other pumps and engines or apparatus employed for raising or pumping
liquids or gases or as engines for producing rotary motion, and consists of a novel
arrangement of double cylinders, steam moved slide valves, pistons and steam ports
whereby the pistons of both cylinders are automatically reciprocated and the steam
or air distributed by the slide valves to the alternate ends of both cylinders by the
movement of the pistons only, without employing any tappet or lever motion to
move the slide valves as in duplex steam and other pressure pumps in present use.
In carrying out this invention we place the cylinders side by side, and above
each cylinder is placed a slide valve working in a slide jacket or casing with suitable
steam and eduction ports as ordinarily used.
The slide valves by preference are made cylindrical and the ports in the slide
valve casing or jacket of one cylinder, communicate with the opposite steam
cylinder in or about the middle of same so that the action is as follows:
The steam being in constant communication with the interior of both slide jackets,
it passes through the slide and main steam port of No. 1 cylinder and acts against
the piston the opposite side of the piston being in communication with the exhaust-
the piston is moved along No. 1 cylinder.
When near the middle of its stroke it uncovers a small port leading to one end
of the slide casing belonging to the opposite or No. 2 cylinder, the steam propelling
the piston now rushes up this said port and reverses the slide valve of the other
or No. 2 cylinder, the exhaust from the said casing escaping by a similar small
port to the eduction side of the piston of No. 1 cylinder.
The slide valve of the other or No. 2 cylinder now having been reversed the
second or No. 2 piston is put in motion and as soon as it reaches about the middle
of its cylinder a similar small port leading to the casing of the slide valve of
No. 1 cylinder is uncovered and No. 1 slide is reversed, thus the motion continues as
the ports in No. 1 cylinder reverse by steam the slide of No. 2 cylinder so the ports
of No. 2 cylinder reverse by steam the slide of No. 1 cylinder and so the motion
continues perfectly automatic.
Suitable and ordinary provision is made for cushioning the slide valves and
pistons to prevent them striking their covers, also levers to move the slide valves
by band when required.
Dated the 10th day of July 1890
GEORGE GORDON PICKING,
WM. HOPKINS,

page_text: COMPLETE SPECIFICATION.
Improvements in Duplex Direct-acting Steam and other Pumps and
Engines.
GEORGE GORDON PICKING and WILLIAM HOPKINS Engineers both of 58 Bow
Road Middlesex E. 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 improvements in the cylinders of duplex direct-
acting steam and other pumps and engines or apparatus employed for raising
or pumping liquids or gases or as engines for producing rotary motion and consists
of a novel arrangement of double cylinders steam moved slide valves pistons and
steam ports whereby the pistons of both cylinders are automatically reciprocated
and the steam or air distributed by the slide valves to the alternate ends of both
cylinders by the movement of the pistons only without employing any tappet or
lever motion to move the slide valves as in duplex steam and other pressure pumps
in present use.
In carrying out this invention we place the cylinders side by side and above each
cylinder is placed a slide valve working in a slide jacket or casing with suitable
steam and eduction ports as ordinarily used.
The slide valves by preference are made cylindrical and the ports in the slide
valve casing or jacket of one cylinder communicate with the opposite steam cylinder
in or about the middle of same so that the action is as follows.
The steam being in constant communication with the interior of both slide jackets
it passes through the slide and main steam port of No. 1 cylinder and acts against
the piston the opposite side of the piston being in communication with the exhaust
the piston is moved along No. 1 cylinder.
When near the middle of its stroke it uncovers a small port leading to one end
of the slide casing belonging to the opposite or No. 2 cylinder the steam propelling
the piston now rushes up this said port and reverses the slide valve of the other or
No. 2 cylinder the exhaust from the said casing escaping by a similar small port
to the eduction side of the piston of No. 1 cylinder. The slide valve of the other
or No. 2 cylinder now having been reversed the second or No. 2 piston is put in
motion and as soon as it reaches about the middle of its cylinder a similar small
port leading to the casing of the slide valve of No. 1 cylinder is uncovered and
No. 1 slide is reversed thus the motion continues.
As the ports in No. 1 cylinder reverse by steam the slide of No. 2 cylinder so the
ports of No. 2 cylinder reverse by steam the slide of No. 1 cylinder and so the
motion continues perfectly automatic.
Suitable and ordinary provision is made for cushioning the slide valves and
pistons to prevent them striking their covers also levers to move the slide.valves
by hand when required.
On the accompanying drawings
Fig. 1 is sectional plan of a duplex pump according to this invention the section
is taken through the casing of the slide valves the slide valves are in this design
placed across the main cylinders but they may be placed longitudinally if preferred
as shewn in Fig. 6.
Fig. 2 is a longitudinal section on line J. J. shewing the small ports for shifting
the valves a similar set of ports being taken from the other cylinder to the slide
i valve B.
Referring to the figures supposing the piston A. to be moving in the direction
of the arrow as soon as it uncovers the port a steam will pass up thence through
the port band move the slide B towards the cover H the exhaust from the slide
casing B. passing through the ports c and d to the eduction side of the piston. A.
the small eduction port e being closed by the position of the slide valve C.

page_text: The motion of the piston D now being reversed (by the movement of the slide B)
when it uncovers a similar port to a steam passes up this port (and port C in
slide C) and reverses the slide C towards the cover I. Fig. 3 shews position of
small ports when reversed and is a section on line K. K of slide thence the piston A
travels towards the end E the port d being now closed and the port e being open
by the slide C, when the piston A on its return stroke uncovers the middle port a,
steam passes up and reverses the slide B towards the cover 1 again and so the motion
continues.
The small eduction ports e and d may sometimes be dispensed with as the
slide valve itself can be provided with a passage to the main exhaust as shewn in
Figs. 4 and 5.
In these fis the small port which comes up from the middle of the cylinders,―gh
and are the main steam ports, thus it will be seen that in one position of the slide
the ports are ready to receive steam from its own cylinder to move the neighbouring
slide to one end, and in the other position ready to move it to the other end without
taking the eduction ports from the slide casings into the main cylinders.
Figs. 6 and 7 shew the slides placed in a line with each cylinder the arrangement
of small ports being the same.
Fig. 8 shews the handle for moving the slides by hand if required.
It is sometimes preferred to make two small steam ports in each cylinder for
moving the neighbouring slide instead of only one so that the piston is compelled
to take a longer stroke before the slide of the other cylinder is reversed this
arrangement is shewn in Fig. 9 the two ports k and serving in place of the one
port a in Fig. 2.
The slide valves are only made cylindrical, by preference they may be ordinary
flat slide valves worked by piston ends in the casing.
The main ports may be in duplicate for the purpose of cushioning if preferred
also the smaller ports for moving the slide valves by steam may be in duplicate for
the purpose of cushioning if preferred.
Duplex cylinders constructed according to this invention may be applied to give
rotary motion to an ordinary right angled crank by suitable guides and connecting
rods as when one piston is in the middle of its stroke it reverses the slide of the
other piston which is at the end of its stroke.
Having thus described our said invention and the manner of performing the same
we wish it understood that we claim
Firstly. In duplex steam and other pumps and engines moving the slide valve of
one main cylinder, by steam from the other main cylinder, substantially as
described.
Secondly. The arrangement of small ports for moving the neighbouring slide
valve by steam, for the purpose and as described.
Thirdly. In duplex steam and other pumps and engines the use of hollow or
cylindrical steam moved slide valves for distributing the steam.
Dated this 18th day of April 1891.
G. G. PICKING.
WM.
HOPKINS.