GB2446531A - Pilot controlled check valve - Google Patents

Pilot controlled check valve Download PDF

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Publication number
GB2446531A
GB2446531A GB0806597A GB0806597A GB2446531A GB 2446531 A GB2446531 A GB 2446531A GB 0806597 A GB0806597 A GB 0806597A GB 0806597 A GB0806597 A GB 0806597A GB 2446531 A GB2446531 A GB 2446531A
Authority
GB
United Kingdom
Prior art keywords
valve
connection
piston
ram
port
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.)
Granted
Application number
GB0806597A
Other versions
GB2446531B (en
GB0806597D0 (en
Inventor
Martin Reuter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Marco Systemanalyse und Entwicklung GmbH
Original Assignee
Marco Systemanalyse und Entwicklung GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Marco Systemanalyse und Entwicklung GmbH filed Critical Marco Systemanalyse und Entwicklung GmbH
Priority to GB0806597A priority Critical patent/GB2446531B/en
Publication of GB0806597D0 publication Critical patent/GB0806597D0/en
Publication of GB2446531A publication Critical patent/GB2446531A/en
Application granted granted Critical
Publication of GB2446531B publication Critical patent/GB2446531B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D15/00—Props; Chocks, e.g. made of flexible containers filled with backfilling material
    • E21D15/50—Component parts or details of props
    • E21D15/51—Component parts or details of props specially adapted to hydraulic, pneumatic, or hydraulic-pneumatic props, e.g. arrangements of relief valves
    • E21D15/512—Arrangement of valves
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D23/00—Mine roof supports for step- by- step movement, e.g. in combination with provisions for shifting of conveyors, mining machines, or guides therefor
    • E21D23/16—Hydraulic or pneumatic features, e.g. circuits, arrangement or adaptation of valves, setting or retracting devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/003—Systems with load-holding valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/01—Locking-valves or other detent i.e. load-holding devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
    • F15B15/1423—Component parts; Constructional details
    • F15B15/1447—Pistons; Piston to piston rod assemblies
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/20—Other details, e.g. assembly with regulating devices
    • F15B15/22—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke
    • F15B15/222—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke having a piston with a piston extension or piston recess which throttles the main fluid outlet as the piston approaches its end position
    • 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
    • F16K15/00—Check valves
    • F16K15/02—Check valves with guided rigid valve members
    • F16K15/06—Check valves with guided rigid valve members with guided stems
    • F16K15/063—Check valves with guided rigid valve members with guided stems the valve being loaded by a spring
    • 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
    • F16K15/00—Check valves
    • F16K15/18—Check valves with actuating mechanism; Combined check valves and actuated valves
    • F16K15/182—Check valves with actuating mechanism; Combined check valves and actuated valves with actuating mechanism
    • F16K15/1826—Check valves which can be actuated by a pilot valve
    • F16K15/186—
    • 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
    • F16K17/0433—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 with vibration preventing means

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mining & Mineral Resources (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Structural Engineering (AREA)
  • Safety Valves (AREA)
  • Check Valves (AREA)

Abstract

A cartridge for an unlockable check valve for a mining support frame ram has a two part cartridge housing 72, 72 coupled by a thread 75. Hollow valve piston 78 having a fluid port A and radial apertures 52 in the housing is spring 84 biased in a closing direction such that a flange 56 engages seat 58 in the housing to separate the fluid port from a load port 54. The valve piston engages within a control piston 76 with a sliding fit. The control piston slides within a bore 60 supplied with control fluid through a port 50 which is spaced from the bore closed end. The circumference of the piston is recessed to provide an annular or ring gap 64 in the port region to provide damping. A circuit is also provided (Fig. 2) in which two such check valves communicate with a ram head end inlet, one (A) connecting to a valve block (A) and the other (R) to tank (R). Control fluid is supplied from a ram rod end line (B).

Description

A valve cartridge and a valve arrangement The present invention relates
to a valve cartridge for an unlockable check valve of a ram for a support frame in underground mining.
Unlockable check valves for rams are required in different sizes. Up to now, valves have also been produced in different sizes for this purpose.
The connections and the hose connections are, however, made with a maximum of DN 20 in the support frame (shield) since the valves inside the associated valve block also have a maximum of DN 20. I...
It is the object of the invention to provide an unlockable check valve which is not prone to vibrating.
* This object is satisfied by the features of claim 1. Advantageous embodi- *.20 ments are characterized by the dependent claims.
*****, * * In accordance with a further aspect of the invention, it relates to a valve arrangement for a ram of a support frame in accordance with the pream-ble of claim 5. Valve arrangements of this type are generally known. The unlockable check valve would have to have a comparatively large con- struction for high pressures and/or flows. However, to permit an in-creased throughflow in such a case with simple means when a very high pressure is exerted onto the rain, for example by rock burst, provision is made, in accordance with the invention, to connect a further unlockable check valve to the piston surface connection of the ram whose control line is connected to the ring surface connection of the ram and whose return circuit is connected to the return line at the outlet of the valve block.
Through this arrangement, the second unlockable check valve acts as a pure relief valve whose outlet is not impeded by the diameter restrictions of the valve block. It is rather the case, in accordance with the invention, that the outlet of this second check valve can flow directly into the return line.
The present invention will be described in the following purely by way of example with reference to advantageous embodiments and to the enclosed drawings. There are shown: * Fig. 1 a section through a valve cartridge; Fig. 2 a valve arrangement for a ram of a support frame; and *** Fig. 3 a section through a ram valve. *..*
S S...
* Fig. 1 shows a section through a valve cartridge for an unlockable check valve or non-return valve of a ram for a support frame. The valve cartridge comprises a cartridge housing consisting of two housing parts 72 and 74 *:: 20 which are screwed together via a screw thread 75. A valve piston 78 is ar-ranged in the cartridge housing and is loaded with force by a piston spring 84.
The valve piston 78 is hollow at the interior and has flow apertures 52 which enable a flow of hydraulic medium between the connection A and the piston surface connection 54 of the associated ram. A ring flange 56 of the valve piston 78 sealingly contacts a sealing seat ring 58 in the position shown in Fig. 1.
The right hand end of the valve piston 78 in Fig. 1 has a smaller diameter than the rest of the valve piston and is received in the interior of a control piston 76, which is of U-shape in cross-section, with a loose fit over a very small ring gap. The control piston 76 is received in a piston bore 60, with a port 50 opening into the piston bore. Hydraulic medium is supplied via this port 50 which unlocks the check valve and which is in communica- tion with the ring surface connection of the ram and with the B connec-tion of the associated valve block.
As Fig. 1 shows, the port 50 is provided spaced apart from the base 62 of the piston bore 60 and opens into the jacket surface of the piston bore spaced apart from the base of the piston bore. In the region of the port 50, * a small ring gap 64 is furthermore provided between the outer periphery of the control piston 76 and the piston bore 60 and is formed by a recess * 15 which is provided at the outer periphery of the control piston at the right hand side in Fig. 1. *.*.
S S..
Furthermore, a thin ring gap 80 is provided in the region of the sealing seat ring between the valve piston 78 and the cartridge housing and ef- :: 20 fects a damped opening of the valve in connection with the arrangement of the port 50.
If the port 50 is charged with pressure, the hydraulic medium first moves via the ring gap 64 into the region of the piston bore 60, which already ef- fects a damping. If the control piston 76 and the valve piston 78 subse-quently move to the left, the further ring gap 80 between the valve piston and the cartridge housing likewise effects a damped opening. To avoid an overdetermination, the control piston and the valve piston are assembled into one another with a loose fit.
Fig. 2 shows a valve arrangement for a ram 10 of a support frame (not shown). In this context, a first unlockable check valve 12 is provided which is connected, on the one hand, to the piston surface connection A' of the ram 10 and, on the other hand, at its A connection to the A connec-tion of a valve block 20. The reference numeral 13 designates a pressure relief valve. A pressure sensor is designated by the reference numeral 15.
As can further be recognized, the control connection of the unlockable check valve is connected to the ring surface connection B' of the ram 10 and to the B connection of the valve block 20.
Furthermore, a second unlockable check valve 14 is provided in accor-dance with the invention whose control connection is in communication with the ring surface connection B' of the ram 10 and with the B connec-* *5 tion of the valve block 20. This second unlockable check valve 14 is con-*...
.... 15 nected, on the one hand, to the piston surface connection A' of the ram 10. The return circuit R of the valve 14 is not connected to the valve block **..
* 20, but to the return circuit R at the outlet of the valve block 20, i.e. di-*..
rectly to the return line. In this manner, more volume can flow out of the ram 10 when the connection B' receives more pressure. Although the : 20 valves 12 and 14 are of the same design, twice the flow amount can be de-livered if, for example, a rock burst occurs.
Fig. 3 shows a section through a ram valve such as is shown schemati-cally with the reference numeral 21 in Fig. 2. Two valve cartridges, such as are shown in Fig. 1, are received in a housing block 30. Reference sym-bol B designates the connection for the function "lower ram". Reference symbol A below it designates the connection for the function "set ram".
Both connections are made via an angle adapter so that the hydraulic hose can move on a change in inclination of the ram. The housing 30 is flanged to the ram using screws. The connection to the ring surface of the ram is designated by B' and the connection to the piston surface of the ram is designated by A'. Reference numeral 32 designates a connection passage. The pressure is measured at the piston surface by the pressure sensor 15. The pressure arising by the load of the rock is limited by the pressure restricting valve 13. * *e ** * * ** * * *a.. *II. S... * S..
S * S. * S * S...
S

Claims (10)

Marco Systemanalyse und M10084PGB2 Entwicklung OmbH What we claim is:
1. A valve cartridge for an unlockable check valve of a ram for a sup-port frame, comprising a cartridge housing (72, 74) in which a valve piston (78), a piston spring (84) and a control piston (76) are pro-vided, said control piston (76) having a U shape in cross-section and a closed bottom, with a port (50) opening into a piston bore (60) be-ing provided in the cartridge housing for the charging of the control piston (76) with pressure, wherein the valve piston (78) is received in * .** a bore of the control piston (76) with a loose fit.
: **
2. A valve cartridge in accordance with claim 1, characterized in that the control piston (76) has a recess at its outer periphery at its one end.
3. A valve cartridge in accordance with claim 1, characterized in that a ring gap (80) is provided in the region of a sealing seat ring (58) be-tween the valve piston (78) and the cartridge housing.
4. A valve cartridge in accordance with claim 1, characterized in that the port (50) opens into the jacket surface of the piston bore (60) spaced apart from the base (62) of the piston bore (60); and in that a ring gap (64) is provided in the region of the port (50) between the outer periphery of the control piston (76) and the piston bore (60).
5. A valve arrangement for a rain (10) of a support frame, comprising an unlockable check valve (12), in particular in accordance with one of the preceding claims, and a pressure relief valve (13), which are connected to the piston surface connection (A') of the ram, with the A connection of the unlockable check valve (12) being connected to the A connection of a valve block (20) and the control connection (B) of the unlockable check valve (12) being connected to the ring sur-face connection (B') of the ram (10) and the B connection of the valve block (20), characterized in that a further unlockable check valve (14) is in * *a see communication with the piston surface connection (A') of the ram . * 15 and its control connection is connected to the ring surface connece:. tion (B') of the ram and its return circuit (R) is connected to the re-I...
turn line at the outlet of the valve block (20). *.*
I
:..::.
6. A valve cartridge in accordance with any one of the preceding claims :" 20 and incorporated in a valve housing (30), there being a further valve cartridge of the same design provided in said valve housing, with said further valve cartridge having a hollow valve piston (78) com-municating at one end with a return line (R) of a fluid return circuit and with said further valve cartridge likewise having a port (50) communicating in said valve housing with said ring surface connec-tion (B') and a port connecting with said piston surface connection (54, A').
7. A valve arrangement for a ram (10) of a support frame, said ram having a piston surface connection (A') for setting the ram and a ring surface connection (B') for lowering the ram, the valve arrange-ment comprising a valve housing (30) having a first connection (54) to said piston surface connection (A'), a second connection to said ring surface connection (B'), a third connection (A) for receiving fluid from a source of fluid for setting the ram, a fourth connection (B) for lowering the rain and a fifth connection (R) for communicating with a return line of a fluid return circuit, the valve housing containing a first unlockable check valve (12) having an inlet connected to said first connection (A'), an outlet communicating with said piston sur-face connection (A') and a port (50) communicating with said fourth connection (B) for unlocking said first check valve (12) in the event of a pressure rise due to a rock burst, the valve housing further con- taining a second unlockable check valve (14) having an outlet com-municating with said fifth connection (R) , an inlet communicating with said first connection (54) to said piston surface connection (A') and a port (50) communicating with said fourth connection (B) for * ** i ** unlocking said check valve in the event of a pressure rise due to a **S rock burst.
S S...
8. A valve arrangement in accordance with claim 7, wherein said valve housing (30) is flanged to said ram (10).
9. A valve arrangement in accordance with claim 7 or 8, wherein said third connection (A) and said fourth connection (B) are connections to a valve block (20) controlling said valve arrangement.
10. A valve arrangement in accordance with any one of the claims 7, 8 and 9, wherein said return line is connected to a return line at an outlet of said valve block (20).
GB0806597A 2005-06-06 2006-06-02 A valve cartridge Expired - Fee Related GB2446531B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB0806597A GB2446531B (en) 2005-06-06 2006-06-02 A valve cartridge

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102005025917A DE102005025917A1 (en) 2005-06-06 2005-06-06 Valve cartridge, for lockable non-return valves for gallery lining frame struts, has main piston and control piston actuated by fluid fed through transverse channel in casing into an annular gap between it and wall of piston mounting bore
GB0806597A GB2446531B (en) 2005-06-06 2006-06-02 A valve cartridge
GB0610874A GB2428276B (en) 2005-06-06 2006-06-02 A valve cartridge

Publications (3)

Publication Number Publication Date
GB0806597D0 GB0806597D0 (en) 2008-05-14
GB2446531A true GB2446531A (en) 2008-08-13
GB2446531B GB2446531B (en) 2009-02-25

Family

ID=36694802

Family Applications (3)

Application Number Title Priority Date Filing Date
GB0822239A Expired - Fee Related GB2453065B (en) 2005-06-06 2006-06-02 A valve arrangement
GB0610874A Expired - Fee Related GB2428276B (en) 2005-06-06 2006-06-02 A valve cartridge
GB0806597A Expired - Fee Related GB2446531B (en) 2005-06-06 2006-06-02 A valve cartridge

Family Applications Before (2)

Application Number Title Priority Date Filing Date
GB0822239A Expired - Fee Related GB2453065B (en) 2005-06-06 2006-06-02 A valve arrangement
GB0610874A Expired - Fee Related GB2428276B (en) 2005-06-06 2006-06-02 A valve cartridge

Country Status (4)

Country Link
CN (1) CN1877174B (en)
DE (1) DE102005025917A1 (en)
GB (3) GB2453065B (en)
PL (1) PL379830A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010037073A2 (en) * 2008-09-29 2010-04-01 Global Engineering Marketing Llc Central tire inflation wheel assembly and valve
US8844596B2 (en) 2008-09-29 2014-09-30 Global Engineering Marketing Llc Central tire inflation wheel assembly, valve and central tire inflation system

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007044641B4 (en) * 2007-09-19 2010-02-11 Marco Systemanalyse Und Entwicklung Gmbh Valve
DE102008009722B4 (en) * 2008-02-19 2012-08-23 Marco Systemanalyse Und Entwicklung Gmbh valve assembly
DE102009025092B4 (en) 2009-06-16 2019-04-25 Marco Systemanalyse Und Entwicklung Gmbh valve cartridge
FR2965034B1 (en) * 2010-09-16 2014-04-18 Peugeot Citroen Automobiles Sa HYDRAULIC DEVICE FOR VEHICLE TRANSMISSION SYSTEM
CN103352996B (en) * 2013-08-14 2016-01-27 上海纳福希阀门有限公司 A kind of axial flow type check valve
CN108006010A (en) * 2017-11-30 2018-05-08 徐州徐工液压件有限公司 The sequential telescopic hydraulic cylinder of mechanical control stroke

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1258604A (en) * 1968-04-23 1971-12-30

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2058412B2 (en) * 1969-08-28 1973-05-25 Bosch
US3795255A (en) * 1972-01-10 1974-03-05 Parker Hannifin Corp Load control and holding valve
DE2946765C2 (en) * 1979-11-20 1986-04-30 Thyssen Industrie Ag, 4300 Essen Releasable check valve
DE3245729A1 (en) * 1982-12-10 1984-06-14 Gewerkschaft Eisenhütte Westfalia, 4670 Lünen Control equipment for hydraulic props of an underground powered support assembly or the like
DE3247420A1 (en) * 1982-12-22 1984-07-05 Mannesmann Rexroth GmbH, 8770 Lohr HYDRAULICALLY UNLOCKABLE CHECK VALVE
DE3407878C1 (en) * 1984-03-02 1985-06-27 Hermann Hemscheidt Maschinenfabrik Gmbh & Co, 5600 Wuppertal Non-return valve for the stamps of walking frames
JP3329397B2 (en) * 1993-04-20 2002-09-30 古河機械金属株式会社 Valve block for hydraulic cylinder
LU88732A1 (en) * 1996-03-25 1997-09-25 Hydrolux Sarl Two-way cartridge valve
US5960814A (en) * 1997-09-12 1999-10-05 Ngt, Llc. Counter balanced locking valve
DE19813909B4 (en) * 1998-03-28 2007-02-15 Dbt Gmbh Hydraulically actuated non-return valve for the removal hydraulics in mining underground operations
DE29921157U1 (en) * 1999-12-01 2000-02-17 Dams Gmbh check valve
PL202250B1 (en) * 2003-05-08 2009-06-30 Dbt Gmbh Hydraulic valve, particularly non-return valve and hydraulic support, particularly hydraulic prop

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1258604A (en) * 1968-04-23 1971-12-30

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010037073A2 (en) * 2008-09-29 2010-04-01 Global Engineering Marketing Llc Central tire inflation wheel assembly and valve
WO2010037073A3 (en) * 2008-09-29 2011-07-21 Global Engineering Marketing Llc Central tire inflation wheel assembly and valve
US8307868B2 (en) 2008-09-29 2012-11-13 Global Engineering Marketing Llc Central tire inflation wheel assembly and valve
US8844596B2 (en) 2008-09-29 2014-09-30 Global Engineering Marketing Llc Central tire inflation wheel assembly, valve and central tire inflation system

Also Published As

Publication number Publication date
GB2446531B (en) 2009-02-25
GB2428276A (en) 2007-01-24
CN1877174B (en) 2010-07-28
GB0806597D0 (en) 2008-05-14
GB2428276B (en) 2008-07-23
DE102005025917A1 (en) 2006-12-07
GB0610874D0 (en) 2006-07-12
GB2453065A (en) 2009-03-25
PL379830A1 (en) 2006-12-11
GB0822239D0 (en) 2009-01-14
CN1877174A (en) 2006-12-13
GB2453065B (en) 2010-01-13

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Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20110602