Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
  • F04B49/02—Stopping, starting, unloading or idling control
  • F04B49/022—Stopping, starting, unloading or idling control by means of pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K17/00—Safety valves; Equalising valves, e.g. pressure relief valves
  • F16K17/02—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side
  • F16K17/04—Safety valves; Equalising valves, e.g. pressure relief valves opening on surplus pressure on one side; closing on insufficient pressure on one side spring-loaded
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K27/00—Construction of housing; Use of materials therefor
  • F16K27/02—Construction of housing; Use of materials therefor of lift valves
• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
  • G05D16/00—Control of fluid pressure
  • G05D16/04—Control of fluid pressure without auxiliary power
  • G05D16/06—Control of fluid pressure without auxiliary power the sensing element being a flexible membrane, yielding to pressure, e.g. diaphragm, bellows, capsule
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/7722—Line condition change responsive valves
  • Y10T137/7837—Direct response valves [i.e., check valve type]
  • Y10T137/7876—With external means for opposing bias
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/8593—Systems
  • Y10T137/85978—With pump
  • Y10T137/86131—Plural
  • Y10T137/86163—Parallel

Definitions

• the invention relates to valves for air compressors, and more particularly, to an unloading/venting valve having integrated therewith a high- pressure protection valve.
• the air compressor on heavy-duty trucks and off-road equipment is constantly in operation.
• the compressor is designed to vent the discharge of the compressor to the atmosphere.
• a governor that regulates the air pressure in the system will send a signal to open a valve, resulting in a venting of the system and a release of air pressure.
• the invention of the integrated compressor high-pressure protection valve is the result of a need to protect the compressor, and other system components, from unintentional high pressure in the air system in the case of a failure in the venting process in normal operation.
• the compressor may stay in the loaded, or on-cycle, condition, and keep building up the air pressure in the air brake system to the point of failure of some components.
• high pressure relief valves are located down-stream in the air system and not in the head of the compressor. While generally providing emergency relief for the entire system, these down stream high- pressure relief valves are more effective in protecting the components in the system which are proximate to the relief valves.
• failures often occur in the winter months, where moisture can collect and freeze, which isolates down-stream high-pressure relief valves from the air compressor. In this case, if a high-pressure situation is encountered, the relief valve may not relieve the pressure at the air compressor, and the air compressor may be damaged.
• Horowitz discloses a control valve for use in a vehicle air brake system to apply brake releasing pressure to spring-actuated brakes.
• the valve includes a protection valve for the vehicle service tank, as well as a check valve for protecting the vehicle emergency tank.
• the valve includes a piston and a shuttle for controlling the passage between the vehicle emergency tank and the spring brake chambers and a check valve for bleeding trapped pressure from the service line.
• Goldfein discloses an air brake system with a multifunction control valve; a multifunction control valve for an air brake system; various sub-valves within the multifunction control valve-including a pressure protection valve, a pressure reducing valve, an emergency control valve, and a syncro valve. In one embodiment all four types of sub-valves are within a single unitary housing of the multifunction valve.
• the Goldfein patent discloses a pressure reducing valve system for use with a separate compressor for reducing the pressure within an air brake system.
• the Goldfein patent does not disclose a system that further acts as a safety release valve as described in the present invention. Rather, even where the sub-valves are within a single unitary housing of the multifunction valve, Goldfein relies upon a separate pressure protection valve that is unassociated with the pressure reducing valve.
• the Goldfein patent does not appear to disclose integrating either of these valves into the compressor. Neither the protection relief valve combination nor the integration of such with the compressor is disclosed in Goldfein.
• an air system with a pressure reducing valve having a discharge port in communication with the air system and a vent comprising a valve body which is biased to form a seal between the discharge port and the vent.
• a governor monitors the air pressure in the system and generates a signal when a first threshold pressure within the system is reached.
• the valve body is movable against the bias in response to the signal generated by the governor, such that the discharge port is in communication with the vent thereby allowing air to escape from the system.
• the valve body may be movable against the bias in response to a second threshold pressure, greater than the first threshold pressure, within the system being reached such that the discharge port is in communication with the vent thereby allowing air to escape from the system.
• the invention may provide an air system with a pressure reducing valve wherein the vent is in communication with an input of the air compressor thereby allowing the pressurized air to recycle through the system.
• the pressure reducing valve may be fitted with a vented cap to maintain atmospheric pressure behind the valve body and the pressure reducing valve may be assembled and installed in one step in a head part of a compressor.
• the invention may provide an air system with a pressure reducing valve wherein, the valve body is a piston and wherein the valve is a shuttle valve comprising a shuttle piston which is biased to form a seal between the discharge part and the vent.
• the shuttle piston may be movable against the bias when the force exerted on the shuttle body resulting from the air pressure in the system and the force resulting from the governor signal exceed the force that causes the seal between the discharge port and the vent.
• the invention may provide an air system with a pressure reducing valve wherein, the governor signal may be an air pressure signal that is sent to a governor cavity.
• the governor cavity may be formed in the space defined between the shuttle piston and the shuttle valve housing, wherein, the shuttle piston is movable against the bias when the force exerted on the shuttle piston resulting from the air pressure in the system and the force resulting from the governor air pressure signal exceed the force that causes the seal between the discharge port and the vent.
• a pressure reducing valve system comprising a shuttle valve having a shuttle piston biased to form a seal between the discharge port and the vent.
• a governor monitors the air pressure of the system and generates a signal when a first threshold pressure within the system is reached and wherein, the shuttle piston is movable against the bias in response to the signal generated by the governor, such that the discharge port is in communication with the vent thereby allowing air to escape from the system.
• the shuttle piston may be movable against the bias in response to a second threshold pressure, greater than the first threshold pressure, within the system being reached such that the discharge port is in communication with the vent thereby allowing air to escape from the system.
• the invention may provide an air system with a pressure reducing valve wherein, the governor signal comprises an air pressure signal sent to a governor cavity which may be formed in the space defined between the shuttle piston and the shuttle valve housing.
• the invention may provide an air system with a pressure reducing valve wherein, the shuttle piston is movable against the bias when the force exerted on the shuttle piston resulting from the air pressure in the system and the force resulting from the governor air pressure signal exceed the force that causes the seal between the discharge port and the vent.
• the vent may be in communication with an input of the air compressor thereby allowing the pressurized air to recycle through the system.
• the shuttle valve may be fitted with a vented cap to maintain atmospheric pressure behind the shuttle piston and the pressure reducing valve may be assembled and installed in one step in a head part of a compressor.
• FIG. 1 is a cross-sectional side view of an unloading/venting valve having integrated therewith a high-pressure protection valve and a typical compressor in accordance with the invention.
• FIG. 2 is an enlarged cross-sectional side view of the unloading/venting valve having integrated therewith a high-pressure protection valve shown in Fig. 1 in the closed position.
• FIG. 3 is an enlarged cross-sectional side view of the unloading/venting valve having integrated therewith a high-pressure protection valve shown in Fig. 1 in the opened position.
• FIG. 4 is an enlarged cross-sectional side view of the governor port and governor cavity of the unloading/venting valve having integrated therewith a high-pressure protection valve shown in Fig. 1.
• FIG. 5 is a cross-sectional top view of the unloading/venting valve having integrated therewith a high-pressure protection valve shown in Fig. 1.
• the invention relates to valves for air compressors, and more particularly, to an unloading/venting valve having integrated therewith a high- pressure protection valve.
• the unloading/venting valve may be of any type known in the art, such as a shuttle valve, ball valve, piston valve, check valve, etc.
• the valve body may be of any type known in the art corresponding to the unloading/venting valve chosen.
• a shuttle valve 10 is utilized having a shuttle piston 30 as the valve body that actuates within the shuttle valve 10.
• a shuttle valve 10 is shown situated in the head of the compressor 12.
• the compressor is shown generally as 14.
• Figures 2 and 3 provide greater detail of the shuttle valve 10.
• the shuttle valve 10 communicates with a vent 20 and a discharge port 22.
• the discharge port 22 communicates with the rest of the air system (not shown) through the system discharge 21 and with the air compressor 14.
• the vent 20 may communicate directly to atmosphere, into an inlet port 18 of the head of the air compressor 12 or any other known means to unload an air compressor.
• the shuttle piston 30 has a seal 42 on one end that will form the seal between the compressor's discharge air passage 22 and vent 20.
• a spring 38 is situated on the other end of the shuttle piston 30 to bias the piston to close the discharge passage 22 from the vent 20.
• the bias on the valve body may be effected by springs, or by pistons or by other means known in the art.
• the spring 38 utilized in the illustrated embodiment is designed to provide a spring force (S) on the shuttle piston 30.
• a cap 28 fitted with an aperture 27 allows the spring chamber 26 to maintain atmospheric pressure.
• the air compressor supplies an air brake system with pressurized air through the system discharge 21 while the system air pressure remains below a first predetermined threshold pressure.
• a governor 50 monitors the air pressure in the system. (See Figures 4 and 5) While the compressor 14 is running below this first predetermined threshold pressure, the unloading/venting valve is closed so that there is no air communication between a discharge passage 22 and a vent 20. In the enlarged cross- sectional view of the shuttle valve in Figure 2, the shuttle piston 30 is shown in the closed position.
• the governor 50 When a predetermined first threshold air pressure is reached in the system, the governor 50, provides a signal to the shuttle valve which causes the piston to shuttle and the valve to open (Figure 3).
• the governor signal may be electrical or servomechanical or by any means known in the art.
• the governor signal may be capable of mechanically causing the valve to open allowing the system to unload/vent.
• the signal comprises pressurized air, as is the case with the embodiment shown in figures 1-5.
• the governor cavity 24 is formed in the space defined between the shuttle valve housing 16 and the shuttle piston 30.
• the shuttle piston 30 has a smaller diameter portion 34 and a larger diameter portion 36.
• the shuttle valve housing 16 is shaped to accommodate the smaller diameter portion 34 and a larger diameter portion 36 of the shuttle piston 30 forming the governor cavity 24.
• the o-ring 44 on the smaller diameter portion 34 and the o-ring 46 on the larger diameter portion 36 seal the governor cavity 24 to allow the shuttle piston 30 to overcome the bias to movement when an air pressure signal is provided from the governor to un-load the compressor 14.
• the system air pressure results in an air pressure force (P) acting upon the seal between the shuttle piston and the discharge port.
• the air pressure of the system provides an air pressure force (P) against the shuttle piston 30 adjacent the piston seal 42 which is opposite to the spring force (S).
• P air pressure force
• S spring force
• G governor force
• the governor force (G) is shown in greater detail in Figure 4.
• FIGs 4 and 5 illustrate how the governor 50 communicates a pressurized air signal when the first threshold air pressure is reached in the air system to the governor cavity 24 through the governor port 25 resulting in governor force (G) acting on the shuttle piston 30 and against the spring force (S). Also when the first threshold air pressure is reached, an air pressure force (P1) acts on the piston 30 against the spring force (S). With both the governor signal force (G) and the system air pressure force (P) contributing to the opening of the valve, now P1 + G > S and the piston 30 shuttles, opening the valve 10 and thereby opening the passage between the discharge port 22 and the vent 20.
• Figure 3 shows the shuttle piston 30 in the open position. The discharge air then escapes through the vent 20 to atmosphere, or as shown in Figure 1, through an input port 18 into the head of the compressor 12.
• the first threshold air pressure setting may be 180 psi for units sold in North America and 250 psi for units sold elsewhere.
• a force (P1) is acting on the piston where it forms the seal with the discharge port and the vent.
• the governor sends a pressurized air signal through the governor port into the governor cavity.
• the combined force from the governor signal pressure (G) acting on the governor cavity and the force from the first threshold air pressure (P1 j acting on the piston where it forms the seal with the discharge port and the vent is greater than the spring bias force (S).
• the valve will open, when G + pi > S.
• the piston shuttles After receiving the signal from the governor, the piston shuttles, which opens communication between the discharge and the vent. The discharge air is then allowed to vent. In the illustrated embodiment, the air is discharged through the inlet passage into the head of the compressor.
• valve does not open at the first threshold pressure due to an unforeseen system failure, the air pressure in the system will continue to increase.
• system failures may include a failure in the governor sensor, the governor failing to receive or send the signal or a failure in the seals forming the governor cavity.
• the unload/venting valve then also performs a high pressure relief function.
• the governor signal force (G) may be greater than zero. Therefore, there may be sufficient pressure in the governor cavity to shuttle the piston prior to the second threshold pressure: The necessary conditions for the system to unload/vent are still met, such that G + P > S.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• General Physics & Mathematics (AREA)
• Automation & Control Theory (AREA)
• Compressor (AREA)
• Safety Valves (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
• Valves And Accessory Devices For Braking Systems (AREA)
• Control Of Fluid Pressure (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (2)

Family

ID=31976810

Family Applications (1)

Country Status (10)

Families Citing this family (41)

Citations (1)

Family Cites Families (16)

• 2002
  • 2002-08-30 US US10/231,771 patent/US7270145B2/en not_active Expired - Lifetime
• 2003
  • 2003-09-02 KR KR1020057003495A patent/KR100689984B1/ko not_active Expired - Fee Related
  • 2003-09-02 JP JP2004531981A patent/JP4271147B2/ja not_active Expired - Fee Related
  • 2003-09-02 EP EP03759217A patent/EP1540217A4/en not_active Withdrawn
  • 2003-09-02 MX MXPA05002265A patent/MXPA05002265A/es active IP Right Grant
  • 2003-09-02 AU AU2003274944A patent/AU2003274944B2/en not_active Ceased
  • 2003-09-02 CA CA 2496909 patent/CA2496909C/en not_active Expired - Fee Related
  • 2003-09-02 WO PCT/US2003/027210 patent/WO2004020880A2/en not_active Ceased
  • 2003-09-02 BR BR0306324A patent/BR0306324A/pt not_active IP Right Cessation
  • 2003-09-02 CN CNB038239310A patent/CN100357646C/zh not_active Expired - Fee Related

Patent Citations (1)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events