CA1188940A - Constant pressure relief valve for an air control valve - Google Patents
Constant pressure relief valve for an air control valveInfo
- Publication number
- CA1188940A CA1188940A CA000436377A CA436377A CA1188940A CA 1188940 A CA1188940 A CA 1188940A CA 000436377 A CA000436377 A CA 000436377A CA 436377 A CA436377 A CA 436377A CA 1188940 A CA1188940 A CA 1188940A
- Authority
- CA
- Canada
- Prior art keywords
- pressure
- valve
- orifice
- air
- inlet orifice
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/22—Control of additional air supply only, e.g. using by-passes or variable air pump drives
- F01N3/227—Control of additional air supply only, e.g. using by-passes or variable air pump drives using pneumatically operated valves, e.g. membrane valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/22—Control of additional air supply only, e.g. using by-passes or variable air pump drives
Abstract
Abstract:
CONSTANT PRESSURE RELIEF VALVE
FOR AN AIR CONTROL VALVE
A constant pressure relief valve (10) for an air control valve maintains the pressure in a secondary air system below a predetermined value. A diaphragm (18) divides the valve housing (12) into two chambers (24 and 28) wherein the first chamber (24) contains the inlet orifice (22) controlled by a valve member (20) and an exhaust orifice (16). The second chamber (28) contains a reference pressure and a valve bias spring (32) cooperating together to provide the constant pressure.
Due to back pressures at the exhaust orifice (16), the lift of valve member (20) is increased to increase flow through the relief valve (10) maintaining the constant relief pressure.
(FIGURE 1)
CONSTANT PRESSURE RELIEF VALVE
FOR AN AIR CONTROL VALVE
A constant pressure relief valve (10) for an air control valve maintains the pressure in a secondary air system below a predetermined value. A diaphragm (18) divides the valve housing (12) into two chambers (24 and 28) wherein the first chamber (24) contains the inlet orifice (22) controlled by a valve member (20) and an exhaust orifice (16). The second chamber (28) contains a reference pressure and a valve bias spring (32) cooperating together to provide the constant pressure.
Due to back pressures at the exhaust orifice (16), the lift of valve member (20) is increased to increase flow through the relief valve (10) maintaining the constant relief pressure.
(FIGURE 1)
Description
CONSTANT PRESSURE RELIEF VALVE
FOR AN AI R CONTROL VALVE
Th;s invention relates to fluid ac~uated control valves in general and more particularly to a constant pressure relief valve for an air control valve.
In order ~o control emissions from internal combustion engines in motor vehicles, manufacturers have added secondary air control systems to improve the combustion and exhaust processes in the engine~ These secondary air control systems generally include an air pump which is driven by the engine for supplying air under pressure and an air control valve responsive to various operating signals, either electrical, hydraulic or pneuma~;c ~o direct the output of the pump to various components in the engine exhaust system~
Due to VariGuS restrictions in the control system and more particularly in ~he air flow system, various back pressures are developed~ Further, since the pump is driven by the vehicle engine, variations in speed of the pump contribute to pres~ure variations, which if not limited, can cause damage to the air pump.
FOR AN AI R CONTROL VALVE
Th;s invention relates to fluid ac~uated control valves in general and more particularly to a constant pressure relief valve for an air control valve.
In order ~o control emissions from internal combustion engines in motor vehicles, manufacturers have added secondary air control systems to improve the combustion and exhaust processes in the engine~ These secondary air control systems generally include an air pump which is driven by the engine for supplying air under pressure and an air control valve responsive to various operating signals, either electrical, hydraulic or pneuma~;c ~o direct the output of the pump to various components in the engine exhaust system~
Due to VariGuS restrictions in the control system and more particularly in ~he air flow system, various back pressures are developed~ Further, since the pump is driven by the vehicle engine, variations in speed of the pump contribute to pres~ure variations, which if not limited, can cause damage to the air pump.
2~ Various air control valves such as that described in U~S. Patent 4,163,543 entitled "A;r Control Valve~ have provided relie~ valves which are spring biased. The disadvantage of such a relief valve is that as back pressures are developed, ~he curve o relie~ pressure plotted against the pump speed or air flow rate ~s not flat but increases as speed or air flow rates increase.
It i5 an advantage of the invention to provide a constant pressure relief valve in an air control valve wherein the pressure from the air pump does not exceed a predetermined value regardless of pump speed, air flow rate, or system back pressures.
These and other ad~antages of the invention will become apparent in the following detailed description and drawings wherein.
.~
Q
FIGURE 1 is a schematic drawing of the relief valJe shown in longitudinal cross-section;
E'IGURE 2 is a longitudinal cross-sectional view of an air control valve embodyihg the relief valve of the present invention; and FIGURE 3 is a graph of the relief pxessure plotted against air pump speed.
Referring ~o ~he FIGURES by the reference characters, the constant press~re relief valve 10 in FIGURE 1 comprises a housing 12, a flow restrictor 14 in the ex~aus~ orifice or por~ 16~ a diaphragm means 18 and valve means 20.
The housing 12, which is typically molded from a plastic-type material able to withstand the environmental conditions found in the engine compartment of a motor vehiclet has an inlet orifice or por~ 22 and an exhaust orifice or port 16. The inle~ orifice 22 terminates within a first chamber 24 of the housing 12 a~ a valve seat 260 Located within or connected to ~he exhaust orifice 16 of the housing 12 is a flow restrictor 14 which in the preferred embodiment comprises silencing material not shown. The purpose of the silencing material is to quiet the noise of the air exhaus~ing from the housing 1~ but 2S in doing so functions as a restrictor whereby the pressure in the first chamber 24 of the housing 12 increases.
A diaphragm means 18 comprising a rubber bellows i~
connected to ~he interior walls o~ the housing 12 and operates ~o divide the housing into a first chamber 24 and a second chamber 28. Both the inlet orifice 22 and ~he exhaust orifice 16 are located in the first chamber 24. Air f~ow is prevented by the diaphragm 18 from flowing be~wçen the two chambers. A vent ~9 is in the ~all of the second chamber ~8 to main~ain the pressure therein a~ some pressure being supplied to the vent.
4~
Operatively connected to the diaphraqm 18 is a valve member 20 which extends from the diaphragm 18 and seats against the valve seat 26 on the inlet orifice 22. As shown in FIGURE 1, the valve member 26 mo~es in a direction normal to the valve seat 26 and is guided by means of a ~uide pin 30 extending from one wall of the housing 12. The guide pin 30 exte~ds into a guide tube in the valve member and both cooperate to keep t~e valve member 20 normal to the valve seat 26. A spring means 32 bi~ses the valve member 20 against the valve seat 26. In the preferred enbodiment, there are one or more vents 29 in the wall of housing 12 for ve~ting the second chamber 28 to atmospheric pressure which becomes the reference pressure. The pressure therefore requi.red to lift the v~lve member 20 from the valve seat 26 is the summation of the reference pressure and the force applied by the spring bias means 32.
. Referring to FIGURE 2 there is illustrated in longitudinal cross-section, an air control valve 34 including the constant pressure relief v~lve 10 of FIGURE 1. The air control valve 34 is silllilar to the ai~
control valve of U.~. Patent 4,163,543 entitled "Air Control Valve"
which issued on August 7, 1979. That patent defines and describes the operation of the air con.rol valve 34 in greater detail.
2Q The air control valve 34 is connected by means of condu.it 36 to an air pump not shown, which provides pressurized air to the input port 22 of the valve 10. Typically the air pump is a vane pum~ driven by means of belts from the drive shaft of the engine of a motor vehicl.e~
A vane pump provides a pulsating air flow and the faster the pump runs ~he closer together the air pulses become hence the higher the pressure of the air. In addition, the flow rate of the pump increases with pump speed sd~ 3-The air control valve 34 contains a main diverter valve 38 and its valve member 40 which valve member operates to cause the air flow from the pump to either be diverted to the exhaust system or to be discharged to the atmosphere when the operation of the motor vehicle does not require ~he use o~ auxiliary air to the exhaust system. Since air, when it is bl~wn or pushed through an orifice ~reates a sound~ there is provided in the air control valve 34 silencing material 42 between the pump input port 44 of ~he control valve 34 and ~he atmosphere.
When th~ engine control system, which is not shown, requires that the auxiliary air or secondary air be applied ~o the exhaust systemt the diverter valve 38 closes the discharge por~ 46 and diverts the air to either one of the exhaust system ports 48, 49. One port 49 is typically connected to the exhaust manifold of the engine and the other port 4~ is connected to the exhaust system near the catalytic converter which is not shown.
In most systems, selection of which exhaust port is to be used is governed by a vacuum motor controlled by a temperatur~ operated vacuum switch.
The constant pressure ~elief valve 10 of the present invention is illuskrated as being in fluid communication with the pump input port 44 at all times. The input orifice 22 of the relie~ valve 10 receives ~he air flow directly from the air pump. The pressure at the face of the valve member 20 is the pressure which the relief valve 10 operates to avoid being exceeded beyond a predetermined value as determined by ~he relief valve 10.
When the relie valve 10 opens, the pressure and the flow f~om the air pump is communicated between the valve seat ~5 and the valve member 20 to the first chamber 24 ~- of the relie valve 10. The air flows through the first chamber 24 to the exhaust orifice 16 and therethrough to the silencing material 42 and to the atmosphere through a series of vents 50. If the pressure in the first chamber~
starts ~ to build up higher than the pressure which caused the valve member 20 to lift off the valve seat 26, this increased pressure operates against the diaphram 18 5 and the valve member 20 causing the valve member 20 to lift higher. This increased lift, increases the air flow and an equilibrium is reached which is the pressure which initially caused the valve member 20 to lit o~f the valve seat 26.
This increased pres~ure is a back pressure developed b~ ~he pressure drop throu~h the restriction or silencing material 42. The combination of reference pressure in the second chamber 28, the force developed by the spring bias means 32 and the back pressure produces a constant pressure in the air being supplied to the exhaus~ systemO
In one application of the preferred embodiment, the reference pressure in the second chamber 28 is atmospheric and the constant relief pressure is 2n inches of mercury~ As illustrated in FIGUR~ ~, the curve of relief pressure plotted against pump speed or fluid flow for the relief valve 10 of the present invention is flat.
In prior art devices where the relief valve 10 has only one chamber which is connected to the exhaust orifice~
the plot of the relief pressure is illustrated by the dashed curve. The reason for the dashed curve is that the back pressure is added to the spring bias of the valve and since the back pressure increases, the relief preæsure increases.
There has thus been shown and illustrated a constant pressure relief valve 10 as used in an air control valve 34 found in a seconda~y or auxiliary air system in a motor vehicle. A cooperation of the diaphragm 18 providing a reference pressure chamber 28 controlling the valve member 20 and the added lift of the valve member 20 by the system back pressure maintains a constant relie p~essure.
It i5 an advantage of the invention to provide a constant pressure relief valve in an air control valve wherein the pressure from the air pump does not exceed a predetermined value regardless of pump speed, air flow rate, or system back pressures.
These and other ad~antages of the invention will become apparent in the following detailed description and drawings wherein.
.~
Q
FIGURE 1 is a schematic drawing of the relief valJe shown in longitudinal cross-section;
E'IGURE 2 is a longitudinal cross-sectional view of an air control valve embodyihg the relief valve of the present invention; and FIGURE 3 is a graph of the relief pxessure plotted against air pump speed.
Referring ~o ~he FIGURES by the reference characters, the constant press~re relief valve 10 in FIGURE 1 comprises a housing 12, a flow restrictor 14 in the ex~aus~ orifice or por~ 16~ a diaphragm means 18 and valve means 20.
The housing 12, which is typically molded from a plastic-type material able to withstand the environmental conditions found in the engine compartment of a motor vehiclet has an inlet orifice or por~ 22 and an exhaust orifice or port 16. The inle~ orifice 22 terminates within a first chamber 24 of the housing 12 a~ a valve seat 260 Located within or connected to ~he exhaust orifice 16 of the housing 12 is a flow restrictor 14 which in the preferred embodiment comprises silencing material not shown. The purpose of the silencing material is to quiet the noise of the air exhaus~ing from the housing 1~ but 2S in doing so functions as a restrictor whereby the pressure in the first chamber 24 of the housing 12 increases.
A diaphragm means 18 comprising a rubber bellows i~
connected to ~he interior walls o~ the housing 12 and operates ~o divide the housing into a first chamber 24 and a second chamber 28. Both the inlet orifice 22 and ~he exhaust orifice 16 are located in the first chamber 24. Air f~ow is prevented by the diaphragm 18 from flowing be~wçen the two chambers. A vent ~9 is in the ~all of the second chamber ~8 to main~ain the pressure therein a~ some pressure being supplied to the vent.
4~
Operatively connected to the diaphraqm 18 is a valve member 20 which extends from the diaphragm 18 and seats against the valve seat 26 on the inlet orifice 22. As shown in FIGURE 1, the valve member 26 mo~es in a direction normal to the valve seat 26 and is guided by means of a ~uide pin 30 extending from one wall of the housing 12. The guide pin 30 exte~ds into a guide tube in the valve member and both cooperate to keep t~e valve member 20 normal to the valve seat 26. A spring means 32 bi~ses the valve member 20 against the valve seat 26. In the preferred enbodiment, there are one or more vents 29 in the wall of housing 12 for ve~ting the second chamber 28 to atmospheric pressure which becomes the reference pressure. The pressure therefore requi.red to lift the v~lve member 20 from the valve seat 26 is the summation of the reference pressure and the force applied by the spring bias means 32.
. Referring to FIGURE 2 there is illustrated in longitudinal cross-section, an air control valve 34 including the constant pressure relief v~lve 10 of FIGURE 1. The air control valve 34 is silllilar to the ai~
control valve of U.~. Patent 4,163,543 entitled "Air Control Valve"
which issued on August 7, 1979. That patent defines and describes the operation of the air con.rol valve 34 in greater detail.
2Q The air control valve 34 is connected by means of condu.it 36 to an air pump not shown, which provides pressurized air to the input port 22 of the valve 10. Typically the air pump is a vane pum~ driven by means of belts from the drive shaft of the engine of a motor vehicl.e~
A vane pump provides a pulsating air flow and the faster the pump runs ~he closer together the air pulses become hence the higher the pressure of the air. In addition, the flow rate of the pump increases with pump speed sd~ 3-The air control valve 34 contains a main diverter valve 38 and its valve member 40 which valve member operates to cause the air flow from the pump to either be diverted to the exhaust system or to be discharged to the atmosphere when the operation of the motor vehicle does not require ~he use o~ auxiliary air to the exhaust system. Since air, when it is bl~wn or pushed through an orifice ~reates a sound~ there is provided in the air control valve 34 silencing material 42 between the pump input port 44 of ~he control valve 34 and ~he atmosphere.
When th~ engine control system, which is not shown, requires that the auxiliary air or secondary air be applied ~o the exhaust systemt the diverter valve 38 closes the discharge por~ 46 and diverts the air to either one of the exhaust system ports 48, 49. One port 49 is typically connected to the exhaust manifold of the engine and the other port 4~ is connected to the exhaust system near the catalytic converter which is not shown.
In most systems, selection of which exhaust port is to be used is governed by a vacuum motor controlled by a temperatur~ operated vacuum switch.
The constant pressure ~elief valve 10 of the present invention is illuskrated as being in fluid communication with the pump input port 44 at all times. The input orifice 22 of the relie~ valve 10 receives ~he air flow directly from the air pump. The pressure at the face of the valve member 20 is the pressure which the relief valve 10 operates to avoid being exceeded beyond a predetermined value as determined by ~he relief valve 10.
When the relie valve 10 opens, the pressure and the flow f~om the air pump is communicated between the valve seat ~5 and the valve member 20 to the first chamber 24 ~- of the relie valve 10. The air flows through the first chamber 24 to the exhaust orifice 16 and therethrough to the silencing material 42 and to the atmosphere through a series of vents 50. If the pressure in the first chamber~
starts ~ to build up higher than the pressure which caused the valve member 20 to lift off the valve seat 26, this increased pressure operates against the diaphram 18 5 and the valve member 20 causing the valve member 20 to lift higher. This increased lift, increases the air flow and an equilibrium is reached which is the pressure which initially caused the valve member 20 to lit o~f the valve seat 26.
This increased pres~ure is a back pressure developed b~ ~he pressure drop throu~h the restriction or silencing material 42. The combination of reference pressure in the second chamber 28, the force developed by the spring bias means 32 and the back pressure produces a constant pressure in the air being supplied to the exhaus~ systemO
In one application of the preferred embodiment, the reference pressure in the second chamber 28 is atmospheric and the constant relief pressure is 2n inches of mercury~ As illustrated in FIGUR~ ~, the curve of relief pressure plotted against pump speed or fluid flow for the relief valve 10 of the present invention is flat.
In prior art devices where the relief valve 10 has only one chamber which is connected to the exhaust orifice~
the plot of the relief pressure is illustrated by the dashed curve. The reason for the dashed curve is that the back pressure is added to the spring bias of the valve and since the back pressure increases, the relief preæsure increases.
There has thus been shown and illustrated a constant pressure relief valve 10 as used in an air control valve 34 found in a seconda~y or auxiliary air system in a motor vehicle. A cooperation of the diaphragm 18 providing a reference pressure chamber 28 controlling the valve member 20 and the added lift of the valve member 20 by the system back pressure maintains a constant relie p~essure.
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a secondary air control system for internal combustion engines having an air pump supplying air to an air control valve for selective distribution to various components in an exhaust system, a constant pressure relief valve operatively connected to the air control valve for limiting the maximum pressure in the system to a predetermined value independently of the speed of the air pump, the constant pressure relief valve comprising:
a housing;
an inlet orifice in said housing in fluid commun-ication with the air pump;
an exhaust orifice in said housing for discharging air;
flow restriction means in said exhaust orifice for generating a back pressure proportional to the amount of fluid flow therethrough;
spring bias means generating a bias force;
a valve member operatively connected to said spring bias means and biased to close said inlet orifice; and a diaphragm located in said housing dividing said housing into two chambers wherein said first chamber in-cludes said inlet and exhaust orifices and said second chamber contains a reference pressure;
said valve member being connected to said diaphragm and being operable to close said inlet orifice when the pressure at said inlet orifice is less than said reference pressure and said bias force, and cooperating with said back pressure for connecting said inlet orifice to said exhaust orifice to limit and maintain the maximum pressure at said inlet orifice to the predetermined value independ-ently of the speed of the air pump and the amount of air flowing through the system.
a housing;
an inlet orifice in said housing in fluid commun-ication with the air pump;
an exhaust orifice in said housing for discharging air;
flow restriction means in said exhaust orifice for generating a back pressure proportional to the amount of fluid flow therethrough;
spring bias means generating a bias force;
a valve member operatively connected to said spring bias means and biased to close said inlet orifice; and a diaphragm located in said housing dividing said housing into two chambers wherein said first chamber in-cludes said inlet and exhaust orifices and said second chamber contains a reference pressure;
said valve member being connected to said diaphragm and being operable to close said inlet orifice when the pressure at said inlet orifice is less than said reference pressure and said bias force, and cooperating with said back pressure for connecting said inlet orifice to said exhaust orifice to limit and maintain the maximum pressure at said inlet orifice to the predetermined value independ-ently of the speed of the air pump and the amount of air flowing through the system.
2. The combination according to Claim 1 wherein said reference pressure is atmospheric and the maximum pressure is equivalent to atmospheric pressure plus the pressure exerted by said spring bias means whereby said valve opening is proportional to both pump pressure and fluid flow rates in the system.
3. The combination according to Claim 1 wherein said exhaust orifice is connected to a restriction means developing a back pressure causing said inlet orifice to open wider thereby increasing the flow rate of the fluid through said first chamber.
4. The combination according to Claim 1 additionally including guide pin means in said second chamber for guiding said valve member in a motion normal to said inlet orifice, said guide pin means out of the fluid flow through the relief valve.
5. The combination according to Claim 1 wherein said diaphragm operates by means of said back pressure to lift said valve member to open said inlet orifice when said inlet pressure is a maximum and to return said valve member to close said inlet orifice when said inlet pressure falls below said maximum pressure, said diaphragm tracking said inlet pressures independently of pump speed.
6. A constant pressure relief valve for an air control valve comprising:
a housing having an exhaust orifice and an inlet orifice adapted to be connected to an air source having pulsating pressure and variable fluid flow rates from an air pump;
flow restriction means connected to said exhaust orifice to develop a back pressure thereat as a function of the flow therethrough;
spring bias means generating a bias force;
a valve member operatively connected to said spring bias means for closing said inlet orifice;
guide pin means for guiding said valve member in a motion normal to said inlet orifice; and a diaphragm connected to said valve member and dividing said housing into two chambers wherein said first chamber contains said inlet orifice and said exhaust orifice and said second chamber contains said spring bias means, said guide pin means and a reference pressure, said diaphragm being responsive to said back pressure to assist opening of said valve member from said inlet orifice when the pressure from the air source is greater than the summation of said bias force and said reference pressure and is applied thereto until an equilibrium pressure level is reached, and being responsive to close said valve member when the summation of said bias force and said reference pressure is greater than the pressure from the air source.
a housing having an exhaust orifice and an inlet orifice adapted to be connected to an air source having pulsating pressure and variable fluid flow rates from an air pump;
flow restriction means connected to said exhaust orifice to develop a back pressure thereat as a function of the flow therethrough;
spring bias means generating a bias force;
a valve member operatively connected to said spring bias means for closing said inlet orifice;
guide pin means for guiding said valve member in a motion normal to said inlet orifice; and a diaphragm connected to said valve member and dividing said housing into two chambers wherein said first chamber contains said inlet orifice and said exhaust orifice and said second chamber contains said spring bias means, said guide pin means and a reference pressure, said diaphragm being responsive to said back pressure to assist opening of said valve member from said inlet orifice when the pressure from the air source is greater than the summation of said bias force and said reference pressure and is applied thereto until an equilibrium pressure level is reached, and being responsive to close said valve member when the summation of said bias force and said reference pressure is greater than the pressure from the air source.
7. The constant pressure relief valve according to Claim 6 wherein said equilibrium pressure level is the maximum system pressure desired which is equal to the summation of said bias force and said reference pressure, said maximum system pressure being maintained when said pump pressure is increasing beyond said level.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US43090682A | 1982-09-30 | 1982-09-30 | |
| US430,906 | 1982-09-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1188940A true CA1188940A (en) | 1985-06-18 |
Family
ID=23709581
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000436377A Expired CA1188940A (en) | 1982-09-30 | 1983-09-09 | Constant pressure relief valve for an air control valve |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0105790A3 (en) |
| JP (1) | JPS5989874A (en) |
| BR (1) | BR8305496A (en) |
| CA (1) | CA1188940A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2260595B (en) * | 1991-10-17 | 1995-05-31 | Dowty Aerospace Gloucester | A pressure relief valve |
| EP3635282B1 (en) * | 2017-06-09 | 2021-12-15 | Buffo, Salvatore | Safety valve for hydraulic systems |
| CN112268130A (en) * | 2020-11-10 | 2021-01-26 | 北京新风航天装备有限公司 | Backpressure system |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5385217A (en) * | 1977-01-06 | 1978-07-27 | Toyota Motor Corp | Controller for secondary air of internal combustion engine |
| US4345737A (en) * | 1979-03-06 | 1982-08-24 | Nippon Soken, Inc. | Linear solenoid valve actuation device |
-
1983
- 1983-09-09 CA CA000436377A patent/CA1188940A/en not_active Expired
- 1983-09-23 EP EP83401867A patent/EP0105790A3/en not_active Withdrawn
- 1983-09-29 JP JP17950683A patent/JPS5989874A/en active Pending
- 1983-09-30 BR BR8305496A patent/BR8305496A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| BR8305496A (en) | 1984-05-15 |
| EP0105790A3 (en) | 1986-03-05 |
| EP0105790A2 (en) | 1984-04-18 |
| JPS5989874A (en) | 1984-05-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEC | Expiry (correction) | ||
| MKEX | Expiry |