Variable pressure valve

The pneumatically controlled, variable oil pressure regulator of the present invention maintains a selected combustion ratio of oil and air to a furnace and includes in preferred embodiments a diaphragm housing for a flexible air diaphragm and a flexible oil diaphragm, each preferably including a rolled peripheral lip portion for maximum extensibility and connected to a valve plug having the shape of a solid of revolution formed by rotating a convexly curved surface such as an arc of a circle of less than approximately 90.degree. or a corresponding portion of a hyperbolic, parabolic, or elliptical curve, which intersects the longitudinal axis of the valve plug stem about the longitudinal axis thereof to approximate an ellipsoidal shape whereby very low minimum flow rates can be effected without oscillation of the valve.

BACKGROUND OF THE INVENTION 
The present invention relates generally to oil pressure regulator valves 
and more particularly to a pneumatically controlled variable oil pressure 
regulator for maintaining a selected combustion ratio of oil and air to a 
furnace, said valve incorporating flexible oil and air diaphragms having 
rolled peripheral portions for maximum extensibility and a valve plug 
approximating the ellipsoidal shape whereby very low flow rates may be 
effected without causing oscillation of the valve. 
The prior art discloses a wide variety of valve mechanisms, many of which 
are overly complex in their elements and structure, resulting in undue 
initial expense and in unreliability and a high cost of maintenance. Other 
prior art valve systems have utilized various valve plug shapes in 
conjunction with different seating shapes. 
The typical prior art valve includes a cone-shaped valve plug seating into 
a circular orifice. Another prior art valve shape is that of the sphere 
seating also into a circular orifice. In both such cases, the area of the 
valve opening varies almost directly as the distance traveled by the valve 
stem varies. For example, a typical cone-type valve has a maximum travel 
of 0.15 inches. At 10% of its maximum capacity, the cone is only 0.015 
inches from the seat. At 1% of maximum capacity, the plug is 0.0015 inches 
from the seat. Because in any regulated flow there are small fluctuations 
in inlet, outlet, and back pressure (analogous to background noise in an 
electronic system), a small change in oil back pressure of the order of 
magnitude of 1/1000th of a pound can be caused by combustion 
reverberation. 
This minute change will move the cone valve plug a distance of the order of 
magnitude of thousands of an inch and close the valve. In such 
circumstances, the outlet pressure will drop and cause the valve to open. 
This oscillating phenomenon may be observed in the prior art cone-type 
valve when it is operated at low flows of from five gallons per hour down 
to fractions of a gallon per hour. 
It is thus a primary object of the present invention 5 to overcome these 
and other deficiencies of the prior art by providing the improved variable 
oil pressure regulator of the present invention, as disclosed and claimed 
hereinbelow. 
SUMMARY OF THE INVENTION 
The pneumatically controlled variable oil pressure regulator of the present 
invention as set forth more fully hereinbelow, is directed to a valve 
including oil and air pressure chambers which are separated respectively 
by air and oil diaphragms, each of which includes a rolled peripheral 
portion for maximum extensibility of the attached valve stem. The valve 
stem connects the air and oil diaphragms thereby to transmit the 
collective pressures received from each. 
The valve stem supports a valve plug at the distal end thereof having a 
shape in the form of a solid of revolution formed by rotating an arc of a 
circle of less than approximately 90.degree. which intersects the 
longitudinal axis of the valve stem about such longitudinal axis, to 
thereby approximate the ellipsoidal shape. The valve seat for the valve 
plug is of the standard circular aperture shape, having a diameter 
slightly larger than that of the valve plug. Thus, when the valve is 
throttled to minimum flows, the plug does not seat on the orifice, but 
simply plugs the orifice as tightly as manufacturing the tolerances will 
allow. Accordingly, the non-seating plug does not shut completely off, and 
unusually low minimum flows can be effected without oscillation caused by 
the cycling of the valve, on and off, at low flow, as has occurred with 
regulators utilizing prior art seating constructions. 
The variable oil pressure regulator of the present invention and exemplary 
embodiments thereof may be more completely understood with reference to 
the following drawing and the detailed description of preferred 
embodiments.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
The pneumatically controlled, variable oil pressure regulator of the 
present invention is utilized for maintaining a selected combustion ratio 
of oil and air to a furnace. The furnace, typically utilized in 
conjunction therewith, includes a combustion air control valve for 
controlling the flow of air to an orifice inlet supplying air to a furnace 
combustion chamber. 
The variable oil pressure regulator of the present invention includes a 
diaphragm housing containing flexible air and oil diaphragms. The air 
diaphragm is sealingly disposed transversely within the diaphragm housing 
to define a first air chamber therein. The first air chamber has a 
pressure impulse line communicating with the combustion air line 
downstream of the combustion air control valve and upstream of the furnace 
combustion chamber orifice inlet, thereby to receive and monitor the air 
pressure thereof. The result is that the air pressure in the combustion 
air line is directed against the flexible air diaphragm which is 
distensible in response thereto. 
A deflectible oil diaphragm is also sealingly disposed transversely within 
the diaphragm housing to define a second air chamber adjacent to the first 
air chamber. The second air chamber is connected to a back pressure 
impulse line communicating with the furnace combustion chamber and to 
receive and monitor the pressure present in the combustion chamber to the 
second air chamber. The result is that the air pressure in the combustion 
chamber is directed against both the air and oil diaphragms to sum 
algebraically the combustion air line pressure and the furnace combustion 
chamber pressure. 
An air diaphragm reenforcing means is preferably disposed in contacting 
relationship with the air diaphragm for substantially reenforcing the 
entirety of the air diaphragm and leaving only the peripheral regions of 
the air diaphragm not reenforced. The variable oil pressure regulator of 
the present invention also includes a similarly structured oil diaphragm 
reenforcing means which is disposed in contacting relationship with the 
oil diaphragm for substantially reenforcing the entirety of the oil 
diaphragm and leaving only the peripheral regions thereof not reenforced. 
A diaphragm spacer is positioned between the air diaphragm reenforcing 
means and the oil diaphragm reenforcing means within the second air 
chamber to dispose the reenforced diaphragms in fixed, spaced relationship 
and to move the oil diaphragm in response to the sum of the combustion air 
line pressure and the combustion chamber pressure. A valve body connected 
to the diaphragm housing and defining an oil inlet chamber and an oil 
outlet chamber is further provided. 
A valve orifice, which is substantially circular in shape in transverse 
cross-section, is disposed internally of the valve body and separates the 
oil inlet chamber from the oil outlet chamber for controlling the flow of 
oil therebetween. 
A valve stem is connected at its proximal end to the oil diaphragm 
reenforcing means and extends longitudinally into the oil outlet chamber, 
thereby to move longitudinally in response to the movement of the oil 
diaphragm, and thereby in response to the algebraically summed pressures 
of the combustion air line and the combustion chamber. A valve plug is 
disposed on and connected to the distal end of the valve stem for 
longitudinal displacement snugly within the valve orifice, but without 
seating on the valve orifice, to regulate the flow of oil from the oil 
inlet chamber to the oil outlet chamber of the valve body. The valve plug 
has a shape approximating the ellipsoical shape, which shape is formed by 
rotating an arc of a circle of less than approximately 90.degree. or a 
corresponding portion of a hyperbolic, parabolic, or elliptical curve, 
which intersects the longitudinal axis of the valve stem about such 
longitudinal axis. 
In preferred embodiments, the variable oil pressure regulator of the 
present invention includes air and oil diaphragms having a rolled lip at 
the periphery thereof for extended longitudinal distensibility within the 
diaphragm housing. 
In yet further alternative preferred embodiments, the oil pressure 
regulator of the present invention may include spring loaded tension means 
operatively connected to the air and oil diaphragms for initially 
determining the longitudinal displacement of the valve plug within the 
valve orifice, which thereby fixes an initial ratio of oil to air 
pressure. This spring-loaded tension means is preferably attached to the 
proximal end of the diaphragm spacer means, and preferably includes two 
coil springs disposed in counterbalancing relationship, at least one of 
which is adjustable in tension. In particular, the spring loaded tension 
means may preferably include an adjusting coil spring which is attached to 
the diaphragm spacer at its distal end and at its proximal end to a screw 
tension adjustment means to exert thereby a longitudinal force in a first 
direction on the connected diaphragms. A second, compensating coil spring 
is preferably disposed between a stationary spring support and the air 
diaphragm to exert a longitudinal force in a second direction thereon. 
These longitudinal, oppositely directed forces in combination initially 
determine the displacment of the valve plug within the valve orifice, and 
thereby control and determine the oil to air ratio. 
The air diaphragm reenforcing means of the variable oil pressure regulator 
of the present invention preferably includes a first reenforcing disc 
disposed within the first air chamber on a first side of the air diaphragm 
and a second reenforcing disc disposed within the second air chamber and 
on the second side of the air diaphragm. The second disc preferably 
includes a peripheral ring extending into the second air chamber adjacent 
to the rolled lip of the air diaphragm for retaining the rolled lip 
between the outer surface of the peripheral ring and the interior surface 
of the diaphragm housing. Each of the first and second air diaphragm 
reenforcing discs includes in preferred embodiments, a centrally disposed 
aperture for extension of the diaphragm spacer therethrough for connection 
with the adjusting coil spring. 
The oil diaphragm reenforcing means is similar in structure to the air 
diaphragm reenforcing means and comprises a first reenforcing disc 
disposed within the oil outlet chamber on one side of the oil diaphragm 
and a second reenforcing disc disposed within the second air chamber and 
on the opposite side of the oil diaphragm. The second disc includes a 
peripheral ring extending into the second air chamber adjacent the rolled 
lip of the oil diaphragm for retaining the rolled lip between the outer 
surface of the oil diaphragm peripheral ring and the interior surface of 
at least one of the diaphragm housing and the valve body oil outlet 
chamber. Each of the first and second oil diaphragm reenforcing discs 
preferably includes a centrally disposed aperture therein for operative 
connection between the valve stem and the diaphragm spacer therethrough. 
Other preferred alternative embodiments of the variable oil pressure 
regulator of the present invention may include a diaphragm housing which 
is separable from the valve body and connected thereto by a retainer clamp 
for expedited inspection and cleaning of the valve stem, valve plug, and 
valve orifice. 
Also, in further alternative preferred embodiments, a check valve assembly 
may be attached to the lower portion of the diaphragm housing. In the 
event of an oil diaphragm rupture, such check valve would prevent the 
leakage of oil therefrom. 
With reference to the drawing and in particular FIG. 1 thereof, wherein an 
exemplary embodiment of the variable oil pressure regulator of the present 
invention is set forth pictorially, there is shown the variable oil 
pressure regulator of the present invention generally at 10. Oil pressure 
regulator 10 includes a diaphragm housing 12 having upper and lower 
connected portions 14, 16, which are sealingly connected by means of 
through bolts 18 engaging sockets 20 matching threaded sockets 22 of the 
upper and lower diaphragm housing portions 14, 16 respectively. Disposed 
within diaphragm housing 12 are flexible air and flexible oil diaphragms 
24 and 26. The flexible air diaphragm 24 is sealingly disposed 
transversely within diaphragm housing 12 preferably by engagement of the 
extreme peripheral portion 28 of flexible air diaphragm 24 in disposition 
between upper and lower portions 14, 16 of diaphragm housing 12. Such 
transversely disposed flexible air diaphragm 24 defines a first air 
chamber 30 within diaphragm housing 12 which is connected to a pressure 
air impulse line communicating with the combustion air downstream of the 
combustion air control valve and upstream of the furnace combustion 
chamber orifice inlet (not shown) to receive and monitor the air pressure 
thereof. 
The flexible oil diaphragm 26 is similarly sealingly disposed transversely 
within lower portion 16 of diaphragm housing 12 and is attached at the 
extreme peripheral portion 32 thereof to such lower portion 16 of 
diaphragm housing 12 by means of a peripheral disc 34. Peripheral disc 34 
is attached by means of threaded bolts 36 to lower portion 16 of the 
diaphragm housing 12. Flexible oil diaphragm 26 defines a second air 
chamber 38 adjacent to first air chamber 30, which is communicated with a 
back pressure impulse line connected to the furnace combustion chamber 
(not shown) to receive and monitor the pressure present in the combustion 
chamber in second air chamber 38. Each of air diaphragm 24 and oil 
diaphragm 26 includes a respective rolled lip portion 40, 42 near 
peripheries 28, 32 thereof for extended longitudinal distensibility within 
diaphragm housing 12. 
Air and oil pressure diaphragms 24, 26 are held in spaced longitudinal 
configuration by means of a diaphragm spacer 44 disposed therebetween and 
within second air chamber 38, such that oil diaphragm 26 will move in 
response to the sum of the combustion air line pressure and the combustion 
chamber pressure as transmitted to first and second air chambers 30, 38. 
Air diaphragm 24 includes a reenforcing means generally 46 which includes a 
first reenforcing disc 48 disposed within first air chamber 30 and on a 
first side 50 of air diaphragm 24. A second reenforcing disc 52 is 
disposed within second air chamber 38 and on the second side 54 of the air 
diaphragm 24, with second disc 52 including a downwardly disposed 
peripheral ring 56 extending into second air chamber 38 adjacent rolled 
lip 40 of air diaphragm 24 to retain rolled lip 40 between the outer 
surface 58 of peripheral ring 56 and the interior surface 60 of diaphragm 
housing 12. First air diaphragm reenforcing means 46 further includes a 
centrally disposed aperture 62 therein for extension of diaphragm spacer 
44 therethrough for connection with an adjusting coil spring 64. 
Similarly, oil diaphragm 26 is reenforced by oil diaphragm reenforcing 
means generally 66, which includes a first reenforcing disc 68 disposed 
within the oil outlet chamber 70 of the valve body 72, and on one side of 
oil diaphragm 26. A second reenforcing disc 74 is disposed within second 
air chamber 38 on the opposite of oil diaphragm 26. Second disc 74 
includes a peripheral ring 76 extending upwardly into second air chamber 
38 adjacent to rolled lip 42 of oil diaphragm 26 for retaining rolled lip 
42 between the outer surface 78 of oil diaphragm peripheral ring 76 and 
the interior surface 80 of at least one of diaphragm housing lower portion 
16 and valve body oil outlet chamber 70. Each of first and second oil 
diaphragm reenforcing disc 68, 74 also includes a centrally disposed 
aperture 82, 84 therein for operative connection between the valve stem 86 
and diaphragm spacer 44 therethrough. 
Valve body 72 of oil pressure regulator of the present invention generally 
10, is connected to diaphragm housing lower portion 16 preferably by means 
of a V-retainer clamp 88 and is thus easily separably therefrom. Valve 
body 72 defines an oil inlet chamber 90 and oil outlet chamber 70. A valve 
orifice 92, which is preferably substantially circular in transverse 
cross-sectional shape is disposed internally of the valve body 72 and 
separates oil inlet chamber 90 from oil outlet chamber 70 for controlling 
the flow of oil therebetween. 
Valve stem 86 is connected at the proximal end thereof to oil diaphragm 
reenforcing means generally 66 and extends longitudinally into oil outlet 
chamber 70 to move in response to the collective movement of oil and air 
diaphragms 24, 26. A valve plug 94 is disposed on and connected to the 
distal end of valve stem 86 for longitudinal displacement snugly, but 
without seating, within valve orifice 92 to regulate the flow of oil from 
oil inlet chamber 90 to oil outlet chamber 70 of valve body 72. Valve plug 
94 has a shape of a solid of revolution formed by rotation an arc of a 
circle of less than approximately 90.degree. which intersects the 
longitudinal axis of valve stem 86 about the longitudinal axis thereof, 
whereby an ellipsoidal shape is approximated. 
The initial position of the interconnected air and oil diaphragms 24, 26 is 
controlled by means of spring tension specifically, adjusting coil spring 
64 is attached at the distal end 96 thereof to diaphragm spacer 44 
proximal end 98, and at the proximal end 100 of adjusting coil spring 64 
to a screw tension adjustment bolt 102 seated within a seal nut 104, 
thereby to exert a longitudinal force in a first direction on the 
interconnected air and oil diaphragms 24, 26. A compensating coil spring 
106 is disposed between a stationary spring support 107 and air diaphragm 
first reenforcing disc 48 to exert a longitudinal force in a second 
direction on the diaphragms 24, 26. The longitudinal oppositely directed 
forces in combination initially determine the displacement of valve plug 
94 with respect to valve orifice 92, and thereby control the oil to air 
ratio through the oil control regulator of the present invention 10. 
The variable oil pressure regulator of the present invention 10 may further 
include, at the extreme bottom portion 108 of valve body 72, a removable 
plug 110 for cleaning oil inlet 90 and valve orifice 92. In combination 
therewith, retainer clamp 88 may be removed to disconnect valve body 72 
from lower portion 16 of diaphragm housing 12 to clean the oil outlet 
chamber 70. 
Although preferred alternative embodiments have been disclosed hereinabove, 
it will be apparent to those skilled in the art that numerous 
modifications which do not depart from the spirit and scope of the 
invention can be devised, and the appended claims are intended to cover 
all such modifications.