Improvements in Pumps, Air Compressors, and like Apparatus.
Year: 1892

page_text: Date of Application, 2nd Feb., 1892
Complete Specification Left. 2nd Nov., 1892-Accepted, 3rd Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements in Pumps, Air Compressors, and like Apparatus.
We, ARTHUR HAMILTON COCHRANE of 5, Victoria Street, Westminster,
Engineer and Contractor, and FRANK TAYLOR of The Sandycroft Foundry and
Engine Works Company Limited, Hawarden near Chester, Managing Director
do hereby declare the nature of this invention to be as follows:-
Our invention relates to pumps such as direct acting steam pumps of various
types and also to air compressors and like apparatus.
According to our invention we so arrange the pump valves that the change in
their position which puts the pump piston in connection with the suction or delivery,
is made while said piston is at rest, so that no reduction of area of the ports is made
while the pump piston is in motion.
The pump valves we prefer to employ are of the piston type, two pistons being
employed connected together and working in a chamber in connection with the
delivery, the other sides of the pistons being in connection with the inlet or suction.
The pistons are of such size and are so arranged as to uncover ports so that the
inlet is placed in connection with one side of the pump piston, while the delivery is
in connection with the other, the arrangement being such that the two piston valves
are always balanced by the two colunins of water.
For the purpose of operating such piston valves in the case of a Tangye pump of
the Cameron and Floyd type the rods of the valves are attached to the plunger
which operates the slide valves of the steam cylinder, the result of which is that
the piston valves will be moved from side to side of the ports while the pump piston
is at rest. In adapting the invention to a Worthington or like, two cylinder pump
an arrangement of pivoted levers is employed which are in connection with the
piston rods common to the steam and pump pistons these levers being further in
connection with the piston valves which valves are in turn in connection with the
slide valves of the steam cylinder and are operated by said levers the "dwell"
arrangement of the slide valve enabling the piston valves to be moved while the
pump piston is at rest as in the arrangement previously described.
Other arrangements than those above described however may be employed for
effecting the same result, while other forms of slide valves such as D valves or
rocking valves may be employed instead of the arrangement of piston valves before
described. We find however that the latter are of advantage especially over the
usual form of lift valves as grit and the like is pushed away from the ports instead
of choking same, and to further the clearance the main body of the pistons is made
in the form of a truncated cone and slightly smaller in diameter than the cylinder,
so that the square edges of the piston rings may push away grit and the like at
each stroke.
By employing the arrangement of steam valves used in the "Tangye" pump of
the Cameron and Floyd type the suction of the pump may be made the delivery
and vice-versa.
In the case of air engines the arrangement of the piston valves enables the load
on the compressing or pumping piston to be kept constant thus preventing racing.
Dated this 2nd day of February 1892.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Agent for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in Pumps, Air Compressors, and like Apparatus.
We, ARTHUR HAMILTON COCHRANE of 5 Victoria Street, Westminster,
Engineer and Contractor, and FRANK TAYLOR of the Sandycroft Foundry and
Engine Works Company Limited, Hawarden near Chester, Managing Director,
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:-
Our invention relates to pumps such as direct acting steam pumps of various
types and also to air compressors and like apparatus.
According to our invention we so arrange the pump valves that the change in
their position which puts the pump piston in connection with the suction or delivery,
is made while said piston is at rest, so that no reduction of area of the ports is made
while the pump piston is in motion.
To clearly explain our invention reference is made to the accompanying drawings
in which
Fig. 1 is a sectional elevation of the pump portion of a Tangye single cylinder
pump with our improvement applied thereto.
Fig. 2 is on the right hand side an end view of Fig. 1 looking in the direction of
the arrow and on the left hand side a section on line xx Fig. 1 looking in the other
direction.
Fig. 3 is a general view shewing the steam cylinder and steam valves in sectional
elevation.
Fig. 4 is a sectional elevation of a two cylinder Worthington pump with our
improvements applied thereto.
Fig. 5 is sectional elevation on the line y-y certain parts however being
omitted.
Fig. 6 is an end view and Fig. 7 a section of one of the piston valve casings or
seats on an enlarged scale.
Fig. 8 is an elevation partly in section of an air compressor cylinder with our
improvements applied thereto.
In the arrangement shewn in Figs. 1 to 3 a is the steam cylinder and 6 the pump
cylinder, ce being the pump valves which are here shewn as being of the piston
type is the suction pipe and e the delivery. The suction pipe d it will be seen
delivers to the chamber the other sides of the piston c c being in communication
with the chamber e' leading to the outlet e the water passing into such chamber e¹
through the openings in the valve casings cc which are alternately covered or
uncovered by the pistons. In the position in which the valves are shewn it will be
seen that the water cylinder 6 at the back of the pump piston is in communication
with the chamber e and discharge e while the forward side of the piston is in
communication with the chamber and suction d so that the pistons c c are balanced
by the pressure. The rod 9 which operates the piston valves passes through both of
same to connect them together as shewn and is in connection with the plunger h
which operates the slide valve i of the steam cylinder a. The operation of this
valve arrangement being well understood it is not necessary to describe same.
will be seen that the piston valves cc being positively connected to the plunger will
be moved only during the movement of same such movement taking place only
while the pump piston is at rest so that no reduction in the area of the water ports
is made while the pump piston is in motion.
It
In Figs. 4 to 7 the same letters of reference are used to designate the same parts.
The pump shewn is of the Worthington type the steam valves being positively
connected with the piston valves cc by means of the rods y g. These rods are
operated by the usual arrangement of pivotted levers shewn, the lever which is
connected by a yoke with the pump rod j operating the short lever h' connected to

page_text: the valve rod g while the lever i connected to the pump rod j¹ operates the lever i¹
connected to the other valve rod g so that the lever which moves the steam valve of
one cylinder is actuated by the piston rod of the other and as the steam valves and
water valves are positively connected it will be seen that the motion and "dwell'
which the steam valves receive enable the piston valves to be moved while the pump
piston is at rest.
"
The air compressor shewn in Fig. 8 will be understood. Its exhaust is at e and
its inlet at d while the rod g is positively worked by any means which will prevent
a reduction of the ports during motion of the piston the arrangement of the valves
enabling them to work almost silently while the load on said piston is kept constant
thus preventing racing.
Other arrangements than those described above however may be employed for
effecting the same result, while other forms of slide valves such as D valves or
rocking valves may be employed instead of the arrangement of piston valves before
described. We find however that the latter are of advantage especially over the
usual form of lift valves as grit and the like is pushed away from the ports instead
of choking same, and to further the clearance the main body of the piston is made
in the form of a truncated cone and slightly smaller in diameter than the cylinder
as shewn in all the illustrations previously referred to so that the square edges of
the piston rings & may push away grit and the like at each stroke.
k
By employing the arrangement of steam valves used in the "Tangye" pump of
the Cameron and Floyd type the suction of the pump may be made the delivery
and vice versa.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what
we claim is:-
1. The improvements in steam pumps air compressors and like apparatus which
consists in causing the reduction of area of the ports of the water, air, or like
cylinder to take place while the piston is at rest substantially as described.
2. The improvements in steam pumps air compressors and like apparatus which
consists in causing the reduction of area of the ports of the water air or like
cylinder to take place while the piston is at rest the valves effecting such reduction
being positively worked substantially as described.
3. The improvements in steam pumps air compressors and like apparatus consisting
in forming the valve pistons substantially as and for the purpose described.
4. The improvements in steam pumps air compressors and like apparatus substan-
tially as described and illustrated.
Dated the 2nd day of November 1902.
PHILIP M. JUSTICE,
Chartered Patent Agent,
55 & 56, Chancery Lane, London, for the Applicants.
PHILIP M. JUSTICE,
Chartered Patent Agent,
55 & 56, Chancery Lane, London, for the Applicants.