Improvements in or relating to Pumps.
Year: 1899

page_text: Date of Application, 29th Dec., 1899
Complete. Specification Left, 10th Aug., 1900-Accepted, 15th Sept., 1900
PROVISIONAL SPECIFICATION.
Improvements in or relating to Pumps.
I, Philip FRANCIS ODDIE, of 9, Mansel Road, Wimbledon, in the County of
Surrey, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to pumps the object being to provide means for com-
pelling the pump valves to work quietly and insure their closing at the correct
time when the pump is running at a high rate of speed.
It is a well known fact that in an ordinary pump fitted with suction and
delivery valves of the usual types any attempt to drive the pump beyond a certain
limit of speed is attended by severe banging and concussive action. This takes
place at the commencement of every stroke and is caused by the change of
pressure in the pump chambers violently forcing the valves onto their seats.
This action can be reduced to some extent by loading the valves with springs
so as to help the valves to close or partially close before the change of pressure
in the pump chamber, due to the return stroke of the plunger, has taken place.
These springs, however, must of necessity be light, or too much resistance
would be offered to the proper opening of the valves. This is especially the case
with the suction valves which are only opened by the atmospheric pressure and
would refuse to open altogether if loaded too heavily.
According to my invention the opening of the valves is not dependent on
the atmospheric pressure but is controlled by the pressure in an adjacent pump
cylinder, there is, therefore, practically no limit to the strength of spring that
can be used and the valves can be made to seat themselves before the change
of pressure takes place in the pump chamber thus avoiding any noise or bang.
A convenient type of pump to which my invention is particularly well adapted
is that known as the "three throw type," that is, a pump having three plungers
connected to a three throw crank; the cranks being placed at an angle of 120°
to one another. In this case the valve or valves in No. 1 pump chamber are
controlled by the pressure in No. 2 pump chamber; the valve in No. 2 is .con-
trolled by the pressure in pump chamber No. 3; whilst valve No. 3 is con-
trolled by the pressure in pump chamber No. 1.
Each pump chamber is divided, into a suction chamber with suction inlet and
a delivery chamber with delivery outlet and contains a suction valve and a
delivery valve.
A plunger or piston working in a suitable cylinder conveniently formed in
the valve seat co-operates with the suction valve.
From this cylinder a pipe or channel provided with a regulating valve com-
municates with the adjacent pump chamber.
Each suction valve is loaded with a heavy spring which presses the valve
hard on to its seat. The force exerted by this spring can be conveniently
regulated by means of a nut.
The time occupied by the closing of the valve will clearly depend on the
time taken by the water in the small cylinder in passing back through the

page_text: pipe into the connected pump chamber. This can be regulated by means of the
throttle valves and can be so arranged that the valve comes to rest shortly
before the plunger has reached the end of its stroke.
I have only considered it necessary to describe my invention as applied to
a pump with three equal plungers attached to a three throw crank, but it will
be obvious that I can use one or more main plungers co-operating with one or
more auxiliary plungers; these auxiliary plungers merely serving to control
the valves of the main plungers.
Instead of generating the pressure for lifting the valves by the other pumps,
or by an accessory piston, the valves may be connected at the proper moments
with a reservoir in which pressure is generated by other means, as, for instance,
by an accumulator, this reservoir being connected with the pistons of the pump-
valves at the proper time by means of driving members operated from the
crank-shaft.
The valves may also be connected with a pressure-supply instead of the
reservoir.
Improvements in or relating to Pumps.
I, PHILIP FRANCIS ODDIE, of 9, Mansel Road, Wimbledon, in the County of
Surrey, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
My invention relates to pumps the object being to provide means for com-
pelling the pump valves to work quietly and insure their closing at the correct
time when the pump is running at a high rate of speed.
It is a well known fact that in an ordinary pump fitted with suction and
delivery valves of the usual types any attempt to drive the pump beyond a certain
limit of speed is attended by severe banging and concussive action. This takes
place at the commencement of every stroke and is caused by the change of
pressure in the pump chambers violently forcing the valves onto their seats.
This action can be reduced to some extent by loading the valves with springs
so as to help the valves to close or partially close before the change of pressure
in the pump chamber, due to the return stroke of the plunger, has taken place.
These springs, however, must of necessity be light, or too much resistance
would be offered to the proper opening of the valves. This is especially the case
with suction valves which are only opened by atmospheric pressure and would
not open at all if loaded too heavily.
According to my invention the opening of the valves is not dependent on
the atmospheric pressure but is controlled by the pressure in an adjacent pump
cylinder or an auxiliary cylinder or a pressure reservoir or a pressure con-
duit there is, therefore, practically no limit to the strength of spring that
can be used and the valves can be made to seat themselves before the change
of pressure takes place in the pump chamber thus avoiding any noise or bang.
A convenient type of pump to which my invention is particularly well adapted
is that known as the three throw type," that is, a pump having three plungers
connected to a three throw crank, the cranks being placed at an angle of 120°
to one another. In this case the valve or valves in No. 1 pump chamber are

page_text: controlled by the pressure in No. pump chamber
111
trolled by the pressure in pump chamber No. 5, whilst valve No. 3 is con-
trolled by the pressure in pump chamber No. 1.
In the accompanying drawing::
Figure 1 is a longitudinal section; and
Figure 2 is a plan partly in section of a pump fitted with suction valves
arranged according to my invention:
Figures 3, 4, 5 and are diagrams illustrating the different positions of a
pump-plunger from the commencement to the end of its suction stroke.
a, b, c are the pump chambers each chamber being provided with a plunger d, e, f
respectively and the plungers being connected to the arms g, h, i respectively
of a three throw crank k.
Each pump chamber is divided into a suction chamber 7 with suction inlet m
and a delivery chamber with delivery outlet o and contains a suction valve 2
and a delivery valve q.
A small plunger working in a suitable cylinder s conveniently formed in the
valve seat co-operates with the suction valve p.
From this cylinders a pipe or channel t provided with a regulating valve u
communicates with the adjacent pump chamber, that is to say, the cylinder s
in pump chamber a is in connection with pump chamber b, the small cylinder s
in pump chamber bis in connection with pump chamber c and the small
cylinder s in pump chamber is in connection with pump chamber a.
Each suction valve is loaded with a heavy spring which presses the valve
hard on to its seat. The force exerted by this spring can be conveniently
regulated by means of a nut w.
In Figures 3 to 6, which respectively shew the positions of the plunger e
from the beginning to the end of its suction stroke, the valve represented is
the suction valve in pump chamber and the small cylinders is, therefore,
in communication with pump chamber c.
When the pump is working the action is as follows:-
In Figure 3 the plunger e is about to commence its suction stroke whilst the
plunger f is on its inward or forcing stroke. Therefore there is pressure in
the small cylinder s which acting on the inner surface of the small plunger r
tends to press the valve open. This, however, will remain closed until the
plunger e commences its outward stroke and relieves the pressure in chamber b
and consequently on the surface of the valve. This having taken place the
pressure acting on the small plunger will force the same upwards and compress
the spring, at the same time opening the valve.
In Figure 4 the plunger e is in the middle of its stroke while the plunger f
being still on its pressure stroke continues, by the pressure it is exerting under
the small plunger to hold the suction valve fully open. In Figure 5 the
plunger e is approaching the end of its stroke and the plunger f has already
commenced its suction stroke and has consequently relieved the pressure under
the small plunger. The spring will now commence to force down the valve
on to its seat.
The time occupied by the closing of the valve will clearly depend on the
time taken by the water in the small cylinder in passing back through the pipe
into the connected pump chamber c. This can be regulated by means of the
throttle valves and can be so arranged that the valve comes to rest shortly
before the plunger has reached the end of its stroke.
Precisely the same action will in turn take place between the other pairs of
plungers, namely, between d and e and between f and d.
I have only considered it necessary to describe my invention as applied to
a pump with three equal plungers attached to a three throw crank, but it will
be obvious that I can use one or more main plungers co-operating with one or
more auxiliary plungers; these auxiliary plungers merely serving to control
the valves of the main plungers,

page_text: Instead of generating the pressure for lifting the valves by the other pumps,
or by an accessory piston, the valves may be connected at the proper moments
with a reservoir in which pressure is generated by other means, as, for instance,
by an accumulator, this reservoir being connected with the pistons of the pump-
valves at the proper time by means of driving members operated from the
crank-shaft,
The valves may also be connected with a pressure-supply instead of the
reservoir.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
-
1. Pumps in which the opening of the inlet valve is effected independently
of the atmospheric pressure by means of the pressure generated by a second
pump-piston, or by an accessory pump, or otherwise, and effecting the opening
of the valves in the course of the suction period, which pressure is removed
before the change of direction of stroke of the first piston in such a way that the
valves are closed, before the change of direction of stroke or of pressure, by a
spring or a weight, substantially as set forth.
2. A pump of the construction referred to in Claim 1 and having several
cylinders with reversed cranks, in which the inlet-valve 7 of one cylinder b
is connected with another cylinder e in which latter, at the commencement of
the suction stroke in the first cylinder, there is pressure which acts upon a
piston connected with the inlet valve of the first cylinder, and by lifting the
piston opens the valve, whereupon, however, this pressure, as the result of the
position of the crank before the reversal of the stroke, or pressure, in the first
cylinder is removed and the valve is previously closed by the spring e, substan-
tially as set forth.
3. A pump of the kind described in Claim 1 in which the lifting of the valves
is effected by the pressure generated by an accessory pump, suitably connected
to and driven from the pump-shaft, substantially as set forth.
4. A pump of the kind described in Claim 1 in which pressure generated in a
reservoir or supply-pipe is utilized for lifting the valves, and this pressure is
carried to or removed from below the valves by driving members operated from
the pump shaft, substantially as set forth.
5. A pump of the kind described in Claims 1 to 4 in which a throttle-valve (1)
is introduced into the pipe leading to the lifting piston of the valves in order
to allow of the movement of the valves being controlled, substantially as set
forth.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.