EP0935715B1 - Device for holding in position the rod of a pressure cylinder - Google Patents

Device for holding in position the rod of a pressure cylinder Download PDF

Info

Publication number
EP0935715B1
EP0935715B1 EP97913266A EP97913266A EP0935715B1 EP 0935715 B1 EP0935715 B1 EP 0935715B1 EP 97913266 A EP97913266 A EP 97913266A EP 97913266 A EP97913266 A EP 97913266A EP 0935715 B1 EP0935715 B1 EP 0935715B1
Authority
EP
European Patent Office
Prior art keywords
shaft
valve
hydraulic cylinder
maintaining
chamber
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 - Lifetime
Application number
EP97913266A
Other languages
German (de)
French (fr)
Other versions
EP0935715A1 (en
Inventor
Jean-Luc Andre
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.)
Lohr Industrie SA
Original Assignee
Lohr Industrie SA
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 Lohr Industrie SA filed Critical Lohr Industrie SA
Publication of EP0935715A1 publication Critical patent/EP0935715A1/en
Application granted granted Critical
Publication of EP0935715B1 publication Critical patent/EP0935715B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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

Definitions

  • the present invention relates to a device for holding in position the rod of a hydraulic cylinder. It also relates to the leak detection in the return circuit of the motor room.
  • a holding device according to the preamble of claim 1 is known from document DE-A-20 36 547.
  • Cylinders are frequently used hydraulics as drive units in assemblies lifting and lowering of a supporting structure. These sets are well known and used in the transport, but also in construction and other places where elevation movements and of lowering a load are daily and require repeated efforts greater than the human strength.
  • a cylinder is typically maintained under charging by a non-return valve inserted in the circuit cylinder supply in the direction passing towards the rod exit chamber.
  • This function of maintenance under load ensures its role as long as the sealing of the valve can be preserved. This one initially exists due to quality controls carried out in the manufacturing workshops. But the valve can present gradually or suddenly a leak after a certain period and this for various reasons related to operation or aging, or even a minor original defect gone unnoticed. we can mention, as a cause, a geometric defect for example of sphericity of the ball, a solid impurity present in the circuit oil and coming to rest on the valve seat or any other cause of poor mechanical contact or local allowance between the valve body and its seat.
  • valve To ensure a function without fail as important as maintaining security, the valve must present a total guarantee of watertightness.
  • lifting cylinders are associated with devices blocking-locking mechanisms for example locking pins or safety stops.
  • the object of the invention is to dispense with the use of these additional mechanical means of restraint, necessary to ensure the safety of the hold in the case of a hydraulic cylinder locked in load holding position.
  • the invention finds multiple applications in many areas when it comes to lifting-lowering of a load with maintenance in position of restraint and more particularly in position extension of the cylinder rod.
  • the holding device. in position of the rod of a hydraulic cylinder 1 is in the form an isolation assembly 2 mounted between a branch 3 and another branch 4 for supplying engine fluid respectively a reentry chamber 5 and a outlet chamber 6 of a rod 7 of the hydraulic cylinder 1.
  • This isolation set 2 forms a block hydraulic 8 containing an airlock chamber 9 called for simply sas convenience reasons.
  • This airlock has a lower orifice 10 provided with a valve primary check valve 11 in hydraulic connection with the outlet chamber 6 of the rod 7 of the jack and facing, an upper orifice 12 provided with a non-return valve 13 in hydraulic communication with a hydraulic input 14 extended by a channel transverse 15 for supplying engine fluid to the outlet chamber 6 from the hydraulic inlet 14.
  • the primary check valves 11 and security 13 are physically separate and mounted passers-by in the direction from top to bottom of the figures, i.e. in the direction of supply of the chamber outlet 6 of rod 7 from arrival hydraulic 14.
  • the primary valve 11 is produced in the form of a non-return valve ball 16 forced as a closing reminder against a seat of suitable shape for example conical 17 crossed in sound center through the lower hole 10.
  • the restoring force is generated by a return spring 18 trapped in a housing 19 at the lower end isolation block 2.
  • the safety check valve 13 is produced according to a first variant in the form of a frustoconical body 20 with active conical surface in contact in closed position with a flange circular 21 of an annular shoulder 22 crossed at its center through the upper opening 12.
  • the safety valve 13 opens conventionally and automatically by pressure incident.
  • the opening of the safety valve 13 can be controlled by an external command to the block isolation 2 for example by the driving force of the pressurized hydraulic fluid supplying the chamber re-entry of the rod or any other means. She additionally causes the commanded opening of the primary valve 11.
  • the safety valve 13 is extended downwards by a lower rod of control 23 which carries, threaded on its lateral surface, a return spring 24 in the closed position.
  • This control rod 23 ends with a free end with a straight thrust front which can pass through the orifice lower 10 of the airlock 9 to push the body of the primary valve 11 in opening, that is to say away from his seat 17 against force return elastic provided by spring 18.
  • the safety valve 13 is integral with a way to slow down its stroke as a reminder of closure in order to defer its closure from that of the primary valve 11. this can guarantee the absence of significant dynamic pressure and therefore of flow in the airlock 9 during the closing phase of the safety valve 13.
  • This characteristic allows in particular consider using a seal to perfect sealing and thus increasing the efficiency of the valve of security.
  • This type of valve with seal will be called fully sealed valve 26. It constitutes the means ideal for closing the airlock 9 and for a reinforced guarantee of the holding in position under load of the cylinder rod.
  • This variant is shown in Figure 4 under the form of a fully sealed valve 26 with seal 27 by toric example resting on a throat-shaped seat 28.
  • One of the merits of the invention relates to the possibility of using a sealing valve total for example such as 26 for the second valve said security 13 due to the lack of pressure dynamic to the right of the seat when the valve.
  • the flyweight 34 of the mechanical link composite 29 has a seal 38 at the neighborhood of its lower end realizing the tightness of this segment with respect to chamber 32 in which the push-piston 30 moves.
  • the upper mobile assembly consists of a last segment 39 in the form of a rod secured to the body of the valve.
  • This rod 39 presents upwards a cylindrical upper end forming a sliding end piston 40 with play along the guide bore 35 formed in the insert 36.
  • This patch 36 delimits laterally with isolation block 2 a room ring 41 through which the engine oil arrives acts on the body of the safety valve 13.
  • the push-piston 30 actuates during opening the safety valve 13 by a motor displacement towards the bottom coming from a control means for example the force generated by the pressure of the working fluid of the reentry chamber 5 of the rod 7 of the actuator on the upper face of the plunger 30 placed in the supply duct of this chamber September.
  • the command to open the valve security 13 may come from some other means or from a other driving source.
  • the damping effect results from the presence of oil contained in the reservoir chamber 42 forming buffer and which will be gradually expelled out of this reservoir chamber 42 during the return stroke of the safety valve 13 as a closing reminder. Indeed, the oil will be removed from this chamber by rolling along the end piston 40 due to the play existing between it and its guide bore 35.
  • the damping effect also results from viscous friction of the valve stem in oil.
  • This damping effect can be used together with an appropriate distribution of the difference in stiffness of return springs valves or with geometric variations of hydraulic components. Either of these parameters can be used in isolation or in combination.
  • the airlock 9 communicates hydraulically by a channel 43 with a sensor or detector 44 sensitive to pressure, for example a pressure switch inserted in a electrical or electronic circuit whose signal is operated to report a leak by a visual, audible or other warning means.
  • a sensor or detector 44 sensitive to pressure, for example a pressure switch inserted in a electrical or electronic circuit whose signal is operated to report a leak by a visual, audible or other warning means.
  • FIG. 2 shows the block mechanical 45 of pressure switch 44 and its two pins outlet 46 and 47 for its electrical connection with the operating circuit.
  • the actuation of the safety valve is ensured by any independent means, for example electromechanical, electromagnetic or any other way.
  • the holding device according to the invention is perfectly reversible as far as concerns the power connections. So the isolation block 2 output can be connected to the reentry chamber 5 and conversely, the output 6 can be connected directly to a source of pressure.
  • the control at the output of the rod 7 of the jack is done by sending for example a pressure calibrated at the hydraulic inlet 14 of the hydraulic block 8.
  • This driving pressure will automatically open one after the other the two valves 13 and 11 against the return force of each of the springs 24 and 18 and will then supply the outlet chamber 6 of the rod.
  • the pressure will be cut off when the rod 7 of the jack will reach a desired output length.
  • the damping of the safety valve will take effect in order to guarantee the delay desired between the closings of the two valves i.e. delayed closing of the safety valve 13 by compared to that of the primary valve 11.
  • the pressure relative in the airlock will then be substantially zero.
  • Figures 5 and 6 relate to a simplified variant of the holding device in position of a charge according to the invention in which general functions are retained and implemented work by the same or equivalent means.
  • the room located under the push-piston 30 no longer communicates with the outside, but with the arrival of the rising engine fluid of the rod 7 of the hydraulic cylinder.
  • the position holding device applies mainly but not exclusively to a hydraulic cylinder 1 supporting a load carried by a support for lifting it and lowering and keeping it safe in a given position.
  • the holding device is a hydraulic isolation unit 2 in the form of a hydraulic block 8 mounted between two branches 3 and 4 engine fluid supply respectively from the reentry chamber 5 and exit chamber 6 of its rod 7 in the case of a double-acting cylinder.
  • the hydraulic block 8 contains an airlock chamber 9 having a lower opening 10 with non-return valve primary 11 in connection with the outlet chamber 6 and an upper orifice 12 provided with the non-return valve 13 in hydraulic communication with a hydraulic inlet 14 extended by a channel transverse 15.
  • the valves 11 and 13 are mounted passers-by from top to bottom of the figures.
  • valve primary 11 is ball 16 elastically recalled in closed position against its seat by a spring 18.
  • the safety valve 13 in the production shown for this variant is of the body type dish 48 circular with shoulder of diameter less than that of his home 49.
  • This fully sealed valve 13 allows ensure that the load remains in position.
  • the clearance 25 existing between the lower end of the rod 23 and the ball 16 determines a degree of freedom of movement between two valves and introduced in the controlled mode the delay in opening the primary valve 11 caused by opening the safety valve 13.
  • valve 13 Maintaining position security is given by valve 13.
  • the effectiveness of this safety valve depends on the holding of its seal after a significant number of maneuvers.
  • the lower end of the counterweight 34 is found next to the end of a piston 40 secured to the valve body through a reservoir chamber 42 filled with oil used as a buffer damper.
  • the slowdown function allowing closing delay of the two valves can be obtained by different means taken individually or in combination with know: the different stiffnesses of the two springs valve reminder, viscous friction of the rod of the valve 13 in the airlock chamber 9 and in general the damping of the rod in the oil and the conformation and dimensions of components Hydraulic.
  • the transverse channel 15 of the inlet hydraulic 14 has a bypass 53 to a buffer chamber 54 located under the push piston 30. From this fact, this buffer chamber 54 no longer has any communication with the outside via a vent. She is connected to inlet 14 and filled with pressurized oil. Consequently the risk of corrosion which originated from its constant communication with the outside is totally eliminated.
  • the inlet 14 coming of the supply line 55 of the chamber 6 of the jack through the device according to the invention is found connected to the cover at the same time as the buffer chamber 54.
  • the controlled movement of the push piston 30 towards the bottom by the pressure of the fluid coming from the conduit 3, causes the safety valve 13 to open then consecutively, for example by the rod 23, after mechanical thrust contact that of the primary valve 11.
  • the ascent of the plunger 30 is guaranteed by a return spring 56.
  • Another advantage of this feature relates to sealing. Sealing constraints are less important because the leaks feed the hydraulic circuit line. The consequence is possibility of removing the seal between the buffer chamber 54 and the arrival of conduit 3 to the part upper part of the piston 30 on the one hand and that which existed between the upper rod 40 of the valve security 13 and the buffer chamber 54 on the other hand.
  • This advantage further increases the reliability of the device.
  • the pressurized working fluid enters the hydraulic block 8 by the branches 15 and 53 towards the safety valve 13 and the buffer chamber 54.
  • This pressure is enough to first open the safety valve 13 then the non-return valve primary 11 to supply the cylinder through its chamber 6 of out of its rod 7.
  • Rod 7 rises with the load it supports up to the desired level programmed or not. The pressure is then cut and the rod comes to a standstill position. Immediately after immobilization, the load causes oil to return for a period of time short.
  • the safety valve 13 closes in a second time in room-airlock 9 in the absence of pressure due to insulation from the prior closing of the primary valve 11. This closing in the absence of dynamic pressure and therefore of flow protects the seal of the safety valve and avoids this one to come out of its housing.
  • the security of maintaining the charge in position is guaranteed by the two non-return valves.
  • the primary ball valve 11 allows 16 by its close immediate maintenance of the charge.
  • valve fails or leaks primary 11, however small it may be, maintaining by this only one valve is no longer guaranteed over time. This drift would lead to an involuntary lowering of the charge, slow but dangerous for the load located in below the platform held by the jack.
  • the load will remain in position practically indefinitely.
  • the control for lowering the rod 7 of the jack under load requires the opening of the two valves.
  • the force causing the opening is given by a control pressure. This can be the pressure acting on the other chamber of the double-acting cylinder or an independent control pressure or piloting.
  • the safety valve stem continues to go down.
  • the lower end of its rod 23 arrives in thrust contact with the shutter element of the primary valve and continuing its travel the constrained in opening.
  • the safety valve being in position open, its seal does not risk damage or leaving his home.
  • the retraction of the cylinder rod can also result from an otherwise ordered opening of valves i.e. independent of pressure driving causing the retraction of the rod.
  • the device according to the invention can be oriented at mounting in the opposite direction to that shown on the figures or according to any other orientation of his support.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Jigs For Machine Tools (AREA)
  • Fluid-Damping Devices (AREA)
  • Load-Engaging Elements For Cranes (AREA)
  • Gripping On Spindles (AREA)
  • Gripping Jigs, Holding Jigs, And Positioning Jigs (AREA)

Abstract

The maintenance device consists of a hydraulic insulation unit (2) mounted between the supply circuits of a cylinder (1). The insulation unit (2) comprises a sluice (9) which has, at each of its two openings, an anti-return valve, one of which, the primary valve (11) is hydraulically connected to the outlet chamber (6) of the shaft (7) of the cylinder (1) and opens toward said chamber; and a safety valve (13) opening in the same direction, with the latter valve closing at a different rate than the primary valve closes. The invention is useful for maintaining the shaft of any cylinder in position, particularly a charged cylinder, and it is of interest to manufacturers of hydraulic devices, particularly lifting cylinders, as well as those who use them.

Description

La présente invention se rapporte à un dispositif de maintien en position de la tige d'un vérin hydraulique. Elle se rapporte accessoirement à la détection des fuites dans le circuit de retour de la chambre motrice.The present invention relates to a device for holding in position the rod of a hydraulic cylinder. It also relates to the leak detection in the return circuit of the motor room.

Un dispositif de maintien selon le préambule de la revendication 1 est connu du document DE-A-20 36 547.A holding device according to the preamble of claim 1 is known from document DE-A-20 36 547.

On utilise fréquemment des vérins hydrauliques comme organes moteurs dans les ensembles d'élévation et d'abaissement d'une structure porteuse. Ces ensembles sont bien connus et utilisés dans le domaine des transports, mais aussi dans le bâtiment et autres lieux sur lesquels les mouvements d'élévation et d'abaissement d'une charge sont quotidiens et nécessitent des efforts répétés et supérieurs à la force humaine.Cylinders are frequently used hydraulics as drive units in assemblies lifting and lowering of a supporting structure. These sets are well known and used in the transport, but also in construction and other places where elevation movements and of lowering a load are daily and require repeated efforts greater than the human strength.

on maintient classiquement un vérin sous charge par un clapet anti-retour inséré dans le circuit d'alimentation du vérin dans le sens passant vers la chambre de sortie de la tige. Cette fonction de maintien sous charge assure son rôle tant que l'étanchéité du clapet peut être préservée. Celle-ci existe au départ en raison des contrôles de qualité effectués dans les ateliers de fabrication. Mais le clapet peut présenter progressivement ou soudainement un défaut d'étanchéité après une certaine période et ceci pour diverses raisons liées au fonctionnement ou au vieillissement, voire à un défaut mineur d'origine passé inaperçu. on peut mentionner, en tant que cause, un défaut géométrique par exemple de sphéricité de la bille, une impureté solide présente dans le circuit d'huile et venant s'immobiliser sur le siège du clapet ou toute autre cause d'un mauvais contact mécanique ou de surépaisseur locale entre le corps du clapet et son siège.a cylinder is typically maintained under charging by a non-return valve inserted in the circuit cylinder supply in the direction passing towards the rod exit chamber. This function of maintenance under load ensures its role as long as the sealing of the valve can be preserved. This one initially exists due to quality controls carried out in the manufacturing workshops. But the valve can present gradually or suddenly a leak after a certain period and this for various reasons related to operation or aging, or even a minor original defect gone unnoticed. we can mention, as a cause, a geometric defect for example of sphericity of the ball, a solid impurity present in the circuit oil and coming to rest on the valve seat or any other cause of poor mechanical contact or local allowance between the valve body and its seat.

Ce défaut engendre une fuite qui, même insignifiante peut provoquer après plusieurs heures de retenue un abaissement lent de la charge, dangereux pour les biens et les personnes situés en dessous.This defect gives rise to a leak which, even insignificant can cause after several hours of restraint slow lowering of the load, dangerous for property and people below.

Cette fonction de maintien s'avère obligatoire dans tous les cas d'utilisation dans lesquels la sécurité du maintien en position de soutien représente une condition importante sinon primordiale.This holding function turns out mandatory in all cases of use in which the security of maintaining in a support position represents an important if not essential condition.

Dans le cas de dispositifs hydrauliques, la garantie de retenue d'une charge par un vérin hydraulique à l'aide d'un clapet anti-retour n'est apportée que par l'étanchéité de ce clapet.In the case of hydraulic devices, the load retention guarantee by a jack hydraulic using a non-return valve brought only by the sealing of this valve.

Pour assurer sans défaillance une fonction aussi importante que la sécurité du maintien, le clapet doit présenter une garantie totale d'étanchéité.To ensure a function without fail as important as maintaining security, the valve must present a total guarantee of watertightness.

Cette garantie totale ne peut exister et, pour cette raison, lorsque la sécurité l'exige, les vérins de levage sont associés à des dispositifs mécaniques de blocage-verrouillage par exemple des broches de verrouillage ou à des butées de sécurité.This total guarantee cannot exist and, for this reason, when security requires, lifting cylinders are associated with devices blocking-locking mechanisms for example locking pins or safety stops.

Ces dispositifs mécaniques de blocage-verrouillage ou de butée ont pour but d'assurer la sécurité du maintien en position des structures porteuses sous charge lors d'un arrêt de fonctionnement prolongé. Ce maintien en position représente une mesure de sécurité pour les biens et les personnes que le vérin et son circuit de commande ne peuvent assurer seuls de façon infaillible en raison des fuites toujours possibles au niveau du clapet anti-retour.These mechanical blocking-locking devices or stop are intended to ensure the safety of maintaining structures in position carriers under load during a stop of operation extended. This holding in position represents a measure security for property and people that the cylinder and its control circuit cannot ensure foolproof alone due to leaks always possible at the non-return valve.

L'invention a pour but de se dispenser de l'utilisation de ces moyens mécaniques additionnels de retenue, nécessaires pour assurer la sécurité du maintien dans le cas d'un vérin hydraulique bloqué en position de retenue de la charge.The object of the invention is to dispense with the use of these additional mechanical means of restraint, necessary to ensure the safety of the hold in the case of a hydraulic cylinder locked in load holding position.

A cet effet, l'invention se rapporte à un dispositif de maintien en position de la tige d'un vérin hydraulique au moins à simple effet comportant une chambre, par exemple de sortie de sa tige et au moins un clapet anti-retour monté dans le circuit d'alimentation de la chambre, passant vers cette chambre, le dispositif de maintien étant constitué d'un bloc hydraulique d'isolement à travers lequel est alimenté cette chambre caractérisé en ce que :

  • le clapet anti-retour dit clapet primaire est complété par un clapet anti-retour de sécurité séparé du clapet primaire et monté en amont dans le circuit d'alimentation de cette chambre, passant dans le même sens vers cette chambre,
  • un sas présentant à chacune de ses deux entrées-sorties un clapet anti-retour dont d'une part le clapet primaire placé le plus proche de cette chambre, et le clapet de sécurité,
  • des moyens de fermeture différée du clapet de sécurité par rapport à celle du clapet primaire,
  • un moyen de commande en ouverture des deux clapets.
To this end, the invention relates to a device for holding in position the rod of an at least single-acting hydraulic cylinder comprising a chamber, for example from its rod outlet and at least one non-return valve mounted in the chamber supply circuit, passing towards this chamber, the holding device consisting of a hydraulic isolation block through which this chamber is supplied, characterized in that:
  • the non-return valve called the primary valve is completed by a non-return safety valve separate from the primary valve and mounted upstream in the supply circuit of this chamber, passing in the same direction towards this chamber,
  • an airlock presenting at each of its two inlets and outlets a non-return valve including on the one hand the primary valve placed closest to this chamber, and the safety valve,
  • means for delayed closure of the safety valve relative to that of the primary valve,
  • a means for controlling the opening of the two valves.

L'invention trouve de multiples applications dans de nombreux domaines dès qu'il s'agit de levage-abaissement d'une charge avec maintien en position de retenue et plus particulièrement en position d'extension de la tige du vérin.The invention finds multiple applications in many areas when it comes to lifting-lowering of a load with maintenance in position of restraint and more particularly in position extension of the cylinder rod.

A titre d'exemple, on peut citer l'élévation de charges en vue du chargement d'un véhicule de transport, l'élévation et le maintien de plate-formes ou de plateaux porteurs sur des véhicules de transport de voitures ou équivalents.As an example, we can cite the elevation loads for the loading of a vehicle of transport, elevation and maintenance of platforms or load-bearing platforms on transport vehicles cars or equivalent.

Divers avantages découlent de l'utilisation du dispositif selon l'invention :

  • elle permet le verrouillage dans n'importe quelle position de la tige du vérin ;
  • le verrouillage est automatique ;
  • pour une fonction de verrouillage automatique, le dispositif hydraulique selon l'invention est peu onéreux ;
  • le dispositif hydraulique apporte une grande sécurité dans le maintien de la charge.
Various advantages arise from the use of the device according to the invention:
  • it allows locking in any position of the cylinder rod;
  • locking is automatic;
  • for an automatic locking function, the hydraulic device according to the invention is inexpensive;
  • the hydraulic device provides great security in maintaining the load.

D'autres caractéristiques et avantages de l'invention apparaítront dans la description qui suit, donnée à titre d'exemple et accompagnée des dessins dans lesquels :

  • la figure 1 est une vue générale schématique en coupe montrant le dispositif de maintien selon l'invention monté sur les branches d'alimentation d'un vérin ;
  • la figure 2 est une vue en coupe longitudinale d'une première réalisation du dispositif de maintien ;
  • les figures 3 et 4 sont respectivement des vues agrandies en coupe longitudinale de la partie centrale du dispositif de maintien dans le cas des deux variantes l'une à clapet conique et l'autre à clapet à étanchéité totale, avec clapets représentés à l'état fermé ;
  • la figure 5 est une vue générale schématique en coupe montrant la variante simplifiée du dispositif de maintien selon l'invention montée sur les branches d'alimentation d'un vérin avec clapets représentés à l'état fermé ;
  • la figure 6 est une vue en coupe longitudinale de la variante simplifiée du dispositif de maintien.
Other characteristics and advantages of the invention will appear in the following description, given by way of example and accompanied by the drawings in which:
  • Figure 1 is a general schematic sectional view showing the holding device according to the invention mounted on the supply legs of a cylinder;
  • Figure 2 is a longitudinal sectional view of a first embodiment of the holding device;
  • FIGS. 3 and 4 are respectively enlarged views in longitudinal section of the central part of the holding device in the case of the two variants, one with a conical valve and the other with a completely sealed valve, with valves shown in the state closed ;
  • Figure 5 is a general schematic sectional view showing the simplified variant of the holding device according to the invention mounted on the supply branches of a cylinder with valves shown in the closed state;
  • Figure 6 is a longitudinal sectional view of the simplified variant of the holding device.

Le dispositif de maintien. en position de la tige d'un vérin hydraulique 1 se présente sous la forme d'un ensemble d'isolement 2 monté entre une branche 3 et une autre branche 4 d'alimentation en fluide moteur respectivement d'une chambre de rentrée 5 et d'une chambre de sortie 6 d'une tige 7 du vérin hydraulique 1.The holding device. in position of the rod of a hydraulic cylinder 1 is in the form an isolation assembly 2 mounted between a branch 3 and another branch 4 for supplying engine fluid respectively a reentry chamber 5 and a outlet chamber 6 of a rod 7 of the hydraulic cylinder 1.

Cet ensemble d'isolement 2 forme un bloc hydraulique 8 renfermant une chambre-sas 9 appelée pour des raisons de commodité simplement sas. Ce sas présente un orifice inférieur 10 pourvu d'un clapet anti-retour primaire 11 en liaison hydraulique avec la chambre de sortie 6 de la tige 7 du vérin et en regard, un orifice supérieur 12 pourvu d'un clapet anti-retour de sécurité 13 en communication hydraulique avec une entrée hydraulique 14 prolongée par un canal transversal 15 d'alimentation en fluide moteur de la chambre de sortie 6 à partir de l'entrée hydraulique 14.This isolation set 2 forms a block hydraulic 8 containing an airlock chamber 9 called for simply sas convenience reasons. This airlock has a lower orifice 10 provided with a valve primary check valve 11 in hydraulic connection with the outlet chamber 6 of the rod 7 of the jack and facing, an upper orifice 12 provided with a non-return valve 13 in hydraulic communication with a hydraulic input 14 extended by a channel transverse 15 for supplying engine fluid to the outlet chamber 6 from the hydraulic inlet 14.

Les clapets anti-retour primaire 11 et de sécurité 13 sont distincts physiquement et montés passants dans le sens du haut vers le bas des figures, c'est-à-dire dans le sens d'alimentation de la chambre de sortie 6 de la tige 7 à partir de l'arrivée hydraulique 14.The primary check valves 11 and security 13 are physically separate and mounted passers-by in the direction from top to bottom of the figures, i.e. in the direction of supply of the chamber outlet 6 of rod 7 from arrival hydraulic 14.

De façon avantageuse, le clapet primaire 11 est réalisé sous la forme d'un clapet anti-retour à bille 16 forcée en rappel de fermeture contre un siège de forme adaptée par exemple conique 17 traversé en son centre par l'orifice inférieur 10. La force de rappel est engendrée par un ressort de rappel 18 emprisonné dans un logement 19 au niveau de l'extrémité inférieure du bloc d'isolement 2.Advantageously, the primary valve 11 is produced in the form of a non-return valve ball 16 forced as a closing reminder against a seat of suitable shape for example conical 17 crossed in sound center through the lower hole 10. The restoring force is generated by a return spring 18 trapped in a housing 19 at the lower end isolation block 2.

Le clapet anti-retour de sécurité 13 est réalisé selon une première variante sous la forme d'un corps tronconique 20 à surface conique active en contact en position de fermeture avec un rebord circulaire 21 d'un épaulement annulaire 22 traversé en son centre par l'orifice supérieur 12.The safety check valve 13 is produced according to a first variant in the form of a frustoconical body 20 with active conical surface in contact in closed position with a flange circular 21 of an annular shoulder 22 crossed at its center through the upper opening 12.

Le clapet de sécurité 13 s'ouvre classiquement et automatiquement par la pression incidente.The safety valve 13 opens conventionally and automatically by pressure incident.

L'ouverture du clapet de sécurité 13 peut être commandée par une commande extérieure au bloc d'isolement 2 par exemple par la force motrice du fluide hydraulique sous pression alimentant la chambre de rentrée de la tige ou tout autre moyen. Elle provoque en plus en cascade l'ouverture commandée du clapet primaire 11.The opening of the safety valve 13 can be controlled by an external command to the block isolation 2 for example by the driving force of the pressurized hydraulic fluid supplying the chamber re-entry of the rod or any other means. She additionally causes the commanded opening of the primary valve 11.

Pour ce faire, le clapet de sécurité 13 se prolonge vers le bas par une tige inférieure de commande 23 qui porte, enfilé sur sa surface latérale, un ressort de rappel 24 en position de fermeture. Cette tige de commande 23 se termine par une extrémité libre à front droit de poussée qui peut traverser l'orifice inférieur 10 du sas 9 pour déplacer par poussée le corps du clapet primaire 11 en ouverture, c'est-à-dire en éloignement de son siège 17 à l'encontre de la force élastique de rappel fournie par le ressort 18.To do this, the safety valve 13 is extended downwards by a lower rod of control 23 which carries, threaded on its lateral surface, a return spring 24 in the closed position. This control rod 23 ends with a free end with a straight thrust front which can pass through the orifice lower 10 of the airlock 9 to push the body of the primary valve 11 in opening, that is to say away from his seat 17 against force return elastic provided by spring 18.

S'agissant de deux pièces séparées, il existe un jeu 25 entre l'extrémité de la tige 23 et la bille 16 du clapet primaire 11 et donc une indépendance de mouvement entre les deux clapets.Being two separate rooms, there are a clearance 25 between the end of the rod 23 and the ball 16 of the primary valve 11 and therefore an independence of movement between the two valves.

Le clapet de sécurité 13 est solidaire d'un moyen de ralentissement de sa course en rappel de fermeture afin de différer sa fermeture par rapport à celle du clapet primaire 11. on peut ainsi garantir l'absence de pression dynamique importante et donc de débit dans le sas 9 pendant la phase de fermeture du clapet de sécurité 13.The safety valve 13 is integral with a way to slow down its stroke as a reminder of closure in order to defer its closure from that of the primary valve 11. this can guarantee the absence of significant dynamic pressure and therefore of flow in the airlock 9 during the closing phase of the safety valve 13.

Cette caractéristique permet notamment d'envisager l'utilisation d'un joint pour parfaire l'étanchéité et accroítre ainsi l'efficacité du clapet de sécurité. Ce type de clapet avec joint sera appelé clapet à étanchéité totale 26. Il constitue le moyen idéal de fermeture du sas 9 et de garantie renforcée du maintien en position sous charge de la tige du vérin. Cette variante est représentée sur la figure 4 sous la forme d'un clapet à étanchéité totale 26 à joint 27 par exemple torique reposant sur un siège en forme de gorge 28.This characteristic allows in particular consider using a seal to perfect sealing and thus increasing the efficiency of the valve of security. This type of valve with seal will be called fully sealed valve 26. It constitutes the means ideal for closing the airlock 9 and for a reinforced guarantee of the holding in position under load of the cylinder rod. This variant is shown in Figure 4 under the form of a fully sealed valve 26 with seal 27 by toric example resting on a throat-shaped seat 28.

Ces clapets à étanchéité totale sont peu résistants à une pression dynamique en raison des risques d'extrusion du joint qu'elle peut provoquer.These fully sealed valves are few resistant to dynamic pressure due to risks of extrusion of the seal that it can cause.

Pour un autre exemple de réalisation d'un clapet à étanchéité totale on pourra envisager que la surface conique du corps du clapet de sécurité 13 représenté sur la figure 3, soit partiellement ou totalement garnie d'un revêtement ou d'un joint d'étanchéité qui viendra se presser en contact d'étanchéité sur l'épaulement 22 avantageusement chanfreiné à cet effet.For another example of making a fully sealed valve we can consider that the conical surface of the safety valve body 13 shown in Figure 3, either partially or fully lined or covered sealing which will be pressed in contact sealing on the shoulder 22 advantageously chamfered for this purpose.

Un des mérites de l'invention concerne la possibilité d'utilisation d'un clapet à étanchéité totale par exemple tel que 26 pour le deuxième clapet dit de sécurité 13 en raison de l'absence de pression dynamique au droit du siège lors de la fermeture du clapet.One of the merits of the invention relates to the possibility of using a sealing valve total for example such as 26 for the second valve said security 13 due to the lack of pressure dynamic to the right of the seat when the valve.

Le moyen de ralentissement de la course retour du clapet de sécurité 13 se matérialise dans l'exemple représenté sous la forme d'une liaison mécanique supérieure composite 29 constituant un équipage mobile guidé. Cette liaison mécanique supérieure composite 29 se compose de trois parties libres en mouvement guidées les unes par rapport aux autres. On distingue la partie supérieure formée d'un piston-poussoir 30 monté étanche par un joint 31, piston-poussoir qui se déplace le long d'une chambre 32 ouverte à l'atmosphère par un évent 33 débouchant sur une face du bloc d'isolement 2.The way to slow down the race return of the safety valve 13 materializes in the example shown in the form of a bond upper mechanical composite 29 constituting a guided mobile equipment. This mechanical connection composite upper 29 consists of three parts free in movement guided with respect to other. We can see the upper part formed by push-piston 30 mounted tight by a seal 31, push-piston which moves along a chamber 32 open to the atmosphere by a vent 33 leading to one side of the isolation block 2.

On remarque ensuite une masselotte 34 libre en coulissement dans un alésage-guide 35 prévu dans une pièce rapportée 36. L'extrémité supérieure 37 de cette masselotte 34 est en contact avec la face inférieure du piston-poussoir 30.We then notice a free flyweight 34 sliding in a guide bore 35 provided in a insert 36. The upper end 37 of this counterweight 34 is in contact with the underside of the plunger 30.

La masselotte 34 de la liaison mécanique composite 29 comporte un joint d'étanchéité 38 au voisinage de son extrémité inférieure réalisant l'étanchéité de ce segment par rapport à la chambre 32 dans laquelle se déplace le piston-poussoir 30.The flyweight 34 of the mechanical link composite 29 has a seal 38 at the neighborhood of its lower end realizing the tightness of this segment with respect to chamber 32 in which the push-piston 30 moves.

L'équipage mobile supérieur se compose d'un dernier segment 39 en forme de tige solidaire du corps du clapet. Cette tige 39 présente vers le haut une extrémité supérieure de forme cylindrique formant un piston d'extrémité 40 coulissant avec jeu le long de l'alésage-guide 35 formé dans la pièce rapportée 36. The upper mobile assembly consists of a last segment 39 in the form of a rod secured to the body of the valve. This rod 39 presents upwards a cylindrical upper end forming a sliding end piston 40 with play along the guide bore 35 formed in the insert 36.

Cette pièce rapportée 36 délimite latéralement avec le bloc d'isolement 2 une chambre annulaire 41 par laquelle arrive l'huile moteur qui agit sur le corps du clapet de sécurité 13.This patch 36 delimits laterally with isolation block 2 a room ring 41 through which the engine oil arrives acts on the body of the safety valve 13.

Les extrémités en regard de la masselotte 34 et du piston d'extrémité 40 sont séparées par un espace formant avec la paroi latérale de l'alésage-guide une chambre-réservoir 42 pleine d'huile utilisée comme tampon amortisseur.The opposite ends of the counterweight 34 and the end piston 40 are separated by a space forming with the side wall of the guide bore a tank chamber 42 full of oil used as shock absorber pad.

Le piston-poussoir 30 actionne en ouverture le clapet de sécurité 13 par un déplacement moteur vers le bas provenant d'un moyen de commande par exemple la force engendrée par la pression du fluide moteur de la chambre de rentrée 5 de la tige 7 du vérin qui s'exerce sur la face supérieure du piston-poussoir 30 placée dans le conduit d'alimentation de cette chambre de rentrée.The push-piston 30 actuates during opening the safety valve 13 by a motor displacement towards the bottom coming from a control means for example the force generated by the pressure of the working fluid of the reentry chamber 5 of the rod 7 of the actuator on the upper face of the plunger 30 placed in the supply duct of this chamber September.

La commande en ouverture du clapet de sécurité 13 peut provenir d'un autre moyen ou d'une autre source motrice.The command to open the valve security 13 may come from some other means or from a other driving source.

L'effet amortisseur résulte de la présence d'huile contenu dans la chambre-réservoir 42 formant tampon et qui sera expulsée progressivement hors de cette chambre-réservoir 42 lors de la course retour du clapet de sécurité 13 en rappel de fermeture. En effet, l'huile va être chassée de cette chambre par laminage le long du piston d'extrémité 40 en raison du jeu existant entre celui-ci et son alésage-guide 35.The damping effect results from the presence of oil contained in the reservoir chamber 42 forming buffer and which will be gradually expelled out of this reservoir chamber 42 during the return stroke of the safety valve 13 as a closing reminder. Indeed, the oil will be removed from this chamber by rolling along the end piston 40 due to the play existing between it and its guide bore 35.

L'effet amortisseur résulte également du frottement visqueux de la tige du clapet de sécurité dans l'huile. Cet effet amortisseur peut être utilisé conjointement avec une répartition adaptée de la différence de raideur des ressorts de rappel des clapets ou avec des variations géométriques des composants hydrauliques. L'un ou l'autre de ces paramètres peut être utilisé isolément ou en combinaison. The damping effect also results from viscous friction of the valve stem in oil. This damping effect can be used together with an appropriate distribution of the difference in stiffness of return springs valves or with geometric variations of hydraulic components. Either of these parameters can be used in isolation or in combination.

Le sas 9 communique hydrauliquement par un canal 43 avec un capteur ou un détecteur 44 sensible à la pression, par exemple un manocontact inséré dans un circuit électrique ou électronique dont le signal électrique est exploité pour signaler une fuite par un moyen avertisseur visuel, sonore ou autre.The airlock 9 communicates hydraulically by a channel 43 with a sensor or detector 44 sensitive to pressure, for example a pressure switch inserted in a electrical or electronic circuit whose signal is operated to report a leak by a visual, audible or other warning means.

On a représenté sur la figure 2 le bloc mécanique 45 du manocontact 44 et ses deux broches de sortie 46 et 47 pour son raccordement électrique avec le circuit d'exploitation.FIG. 2 shows the block mechanical 45 of pressure switch 44 and its two pins outlet 46 and 47 for its electrical connection with the operating circuit.

Dans le cas d'un vérin hydraulique à simple effet, l'actionnement du clapet de sécurité est assuré par un moyen quelconque indépendant, par exemple électromécanique, électromagnétique ou tout autre moyen.In the case of a single hydraulic cylinder indeed, the actuation of the safety valve is ensured by any independent means, for example electromechanical, electromagnetic or any other way.

Par ailleurs, le dispositif de maintien selon l'invention est parfaitement réversible en ce qui concerne les branchements d'alimentation. Ainsi, la sortie du bloc d'isolement 2 peut être reliée à la chambre de rentrée 5 et inversement, la chambre de sortie 6 peut être reliée directement à une source de pression.Furthermore, the holding device according to the invention is perfectly reversible as far as concerns the power connections. So the isolation block 2 output can be connected to the reentry chamber 5 and conversely, the output 6 can be connected directly to a source of pressure.

On expliquera tout d'abord le fonctionnement du vérin 1 en déplacement de sa tige 7 pour des besoins de levage ou d'abaissement, puis le fonctionnement du bloc d'isolement 2 en maintien de position sous charge correspondant à la hauteur d'élévation souhaitée.We will first explain the operation cylinder 1 moving its rod 7 for needs lifting or lowering, then operating the isolation block 2 in position maintenance under load corresponding to the desired elevation height.

La commande en sortie de la tige 7 du vérin s'effectue par l'envoi par exemple d'une pression calibrée à l'entrée hydraulique 14 du bloc hydraulique 8. Cette pression motrice ouvrira automatiquement l'un après l'autre les deux clapets 13 et 11 à l'encontre de la force de rappel de chacun des ressorts 24 et 18 et viendra ensuite alimenter la chambre de sortie 6 de la tige. On coupera la pression lorsque la tige 7 du vérin atteindra une longueur de sortie voulue.The control at the output of the rod 7 of the jack is done by sending for example a pressure calibrated at the hydraulic inlet 14 of the hydraulic block 8. This driving pressure will automatically open one after the other the two valves 13 and 11 against the return force of each of the springs 24 and 18 and will then supply the outlet chamber 6 of the rod. The pressure will be cut off when the rod 7 of the jack will reach a desired output length.

Aussitôt la pression coupée, les forces de rappel des ressorts 18 et 24 jusque là dépassées par la force engendrée par la pression motrice, tendent à repousser les clapets 11 et 13 en position de fermeture.As soon as the pressure is cut, the forces of recall of springs 18 and 24 hitherto exceeded by the force generated by the driving pressure, tend to push the valves 11 and 13 back to the closing.

L'amortissement du clapet de sécurité produira son effet en vue de garantir le retard souhaité entre les fermetures des deux clapets c'est-à-dire la fermeture différée du clapet de sécurité 13 par rapport à celle du clapet primaire 11. La pression relative dans le sas sera alors sensiblement nulle.The damping of the safety valve will take effect in order to guarantee the delay desired between the closings of the two valves i.e. delayed closing of the safety valve 13 by compared to that of the primary valve 11. The pressure relative in the airlock will then be substantially zero.

Lors d'une fuite éventuelle du clapet primaire 11, qui ne peut se produire pour des raisons mécaniques qu'au moment de la fermeture de ce clapet, la pression statique régnant dans le sas deviendra rapidement supérieure au seuil de calibrage du manocontact 44 et déclenchera l'alerte.In the event of a valve leak primary 11 which cannot happen for reasons mechanical at the time of closing of this valve, the static pressure in the airlock will become quickly above the calibration threshold of the pressure switch 44 and will trigger the alert.

Cette augmentation de pression atteindra vite une valeur d'équilibre correspondant à la neutralisation du débit de fuite car le clapet de sécurité 13 assure alors l'étanchéité à lui seul.This pressure increase will quickly reach an equilibrium value corresponding to the neutralization of the leakage rate because the valve security 13 then ensures sealing on its own.

Pour actionner la tige du vérin en rentrée, on envoie la pression dans la chambre de rentrée 5. Celle-ci arrivant au piston-poussoir 30 l'actionnera vers le bas, provoquant par déplacement de l'équipage mobile l'ouverture en série, l'un après l'autre, des clapets 13 puis 11 afin de libérer le fluide hors de la chambre de sortie 6 à travers le sas 9.To actuate the rod of the cylinder in reentry, the pressure is sent to the reentry chamber 5. This arriving at the push piston 30 will actuate it down, causing movement of the crew mobile opening in series, one after the other, valves 13 then 11 in order to release the fluid out of the outlet chamber 6 through the airlock 9.

Les figures 5 et 6 se rapportent à une variante simplifiée du dispositif de maintien en position d'une charge selon l'invention dans laquelle les fonctions générales sont conservées et mises en oeuvre par les mêmes moyens ou des moyens équivalents.Figures 5 and 6 relate to a simplified variant of the holding device in position of a charge according to the invention in which general functions are retained and implemented work by the same or equivalent means.

La surveillance de la pression dans la chambre-sas 9 s'est avérée non indispensable.Monitoring the pressure in the chamber-sas 9 proved not to be essential.

Par ailleurs, la chambre située sous le piston-poussoir 30 ne communique plus avec l'extérieur, mais avec l'arrivée du fluide moteur de montée de la tige 7 du vérin hydraulique.In addition, the room located under the push-piston 30 no longer communicates with the outside, but with the arrival of the rising engine fluid of the rod 7 of the hydraulic cylinder.

Les éléments et organes principaux restent maintenus fonctionnellement identiques et comportent en général les mêmes références.The main elements and organs remain kept functionally identical and include general the same references.

Pour la commodité du lecteur, il est apparu souhaitable de redonner ci-après une brève description d'ensemble.For the convenience of the reader, it appeared desirable to give a brief description below overall.

Le dispositif de maintien en position selon l'invention s'applique principalement mais non exclusivement à un vérin hydraulique 1 soutenant une charge portée par un support en vue de son levage et abaissement et de son maintien en toute sécurité dans une position donnée.The position holding device according to the invention applies mainly but not exclusively to a hydraulic cylinder 1 supporting a load carried by a support for lifting it and lowering and keeping it safe in a given position.

Le dispositif de maintien en position est un ensemble hydraulique d'isolement 2 sous la forme d'un bloc hydraulique 8 monté entre deux branches 3 et 4 d'alimentation en fluide moteur respectivement de la chambre de rentrée 5 et la chambre de sortie 6 de sa tige 7 dans le cas d'un vérin à double effet.The holding device is a hydraulic isolation unit 2 in the form of a hydraulic block 8 mounted between two branches 3 and 4 engine fluid supply respectively from the reentry chamber 5 and exit chamber 6 of its rod 7 in the case of a double-acting cylinder.

Le bloc hydraulique 8 renferme une chambre-sas 9 comportant un orifice inférieur 10 à clapet anti-retour primaire 11 en liaison avec la chambre de sortie 6 et un orifice supérieur 12 pourvu du clapet anti-retour de sécurité 13 en communication hydraulique avec une entrée hydraulique 14 prolongée par un canal transversal 15. Les clapets 11 et 13 sont montés passants du haut vers le bas des figures.The hydraulic block 8 contains an airlock chamber 9 having a lower opening 10 with non-return valve primary 11 in connection with the outlet chamber 6 and an upper orifice 12 provided with the non-return valve 13 in hydraulic communication with a hydraulic inlet 14 extended by a channel transverse 15. The valves 11 and 13 are mounted passers-by from top to bottom of the figures.

Dans la réalisation représentée, le clapet primaire 11 est à bille 16 rappelée élastiquement en position de fermeture contre son siège par un ressort 18.In the embodiment shown, the valve primary 11 is ball 16 elastically recalled in closed position against its seat by a spring 18.

Le clapet de sécurité 13 dans la réalisation représentée pour cette variante est du type à corps plat 48 circulaire à épaulement de diamètre inférieur à celui de son logement 49.The safety valve 13 in the production shown for this variant is of the body type dish 48 circular with shoulder of diameter less than that of his home 49.

Il comporte une gorge annulaire 50 dans laquelle est logé un joint d'étanchéité 51 par exemple torique. Il est rappelé élastiquement en position de fermeture contre son siège par un ressort coaxial 52 de rappel monté sur la naissance de la tige de commande 23 dont l'extrémité inférieure peut traverser l'orifice inférieur 10 en vue d'une action mécanique de poussée sur la bille 16.It has an annular groove 50 in which is housed a seal 51 for example ring. It is resiliently recalled to the position of closing against its seat by a coaxial spring 52 of reminder mounted on the birth of the control rod 23 the lower end of which can pass through the opening lower 10 for mechanical thrust action on the ball 16.

Ce clapet 13 à étanchéité totale permet de garantir le maintien en position de la charge.This fully sealed valve 13 allows ensure that the load remains in position.

Comme déjà indiqué, le jeu 25 existant entre l'extrémité inférieure de la tige 23 et la bille 16 détermine un degré de liberté de mouvement entre les deux clapets et introduit dans le mode commandé le retard à l'ouverture du clapet primaire 11 provoquée par l'ouverture du clapet de sécurité 13.As already indicated, the clearance 25 existing between the lower end of the rod 23 and the ball 16 determines a degree of freedom of movement between two valves and introduced in the controlled mode the delay in opening the primary valve 11 caused by opening the safety valve 13.

La sécurité du maintien en position est donnée par le clapet 13. Cependant, l'efficacité de ce clapet de sécurité dépend de la tenue de son joint après un nombre important de manoeuvres.Maintaining position security is given by valve 13. However, the effectiveness of this safety valve depends on the holding of its seal after a significant number of maneuvers.

La fiabilité de ce joint résulte de la fermeture du clapet sous débit faible et de préférence quasi nul.The reliability of this seal results from the closing the valve under low flow and preferably close to zero.

Ces conditions sont réalisées si l'on peut assurer dans tous les cas la fermeture postérieure du clapet de sécurité 13 par rapport au clapet primaire 11.These conditions are met if we can in all cases ensure the posterior closure of the safety valve 13 relative to the primary valve 11.

Cette caractéristique résultait dans les variantes ci-dessus notamment d'un ralentissement approprié à la fermeture du clapet de sécurité 13 par un moyen de ralentissement qui consistait à fractionner l'équipage supérieur mobile en une masselotte 34 libre en coulissement axial dont l'extrémité supérieure était en contact avec la base d'un piston-poussoir 30 se déplaçant le long d'une chambre 32 ouverte à l'atmosphère.This characteristic resulted in above variants including a slowdown suitable for closing the safety valve 13 by a means of slowing down which consisted in fractioning the upper mobile crew in a free flyweight 34 in axial sliding whose upper end was in contact with the base of a push piston 30 moving along a room 32 open to the atmosphere.

L'extrémité inférieure de la masselotte 34 se trouvait en regard de l'extrémité d'un piston 40 solidaire du corps du clapet à travers une chambre-réservoir 42 remplie d'huile utilisée comme tampon amortisseur.The lower end of the counterweight 34 is found next to the end of a piston 40 secured to the valve body through a reservoir chamber 42 filled with oil used as a buffer damper.

Dans la variante présentement décrite et représentée sur les figures 5 et 6, il n'existe plus de masselotte 34 constituant un intermédiaire mécanique mobile entre la clapet de sécurité 13 et le piston-poussoir 30 d'actionnement.In the variant currently described and shown in Figures 5 and 6, there is no longer any counterweight 34 constituting a mechanical intermediate movable between the safety valve 13 and the push piston 30 actuation.

Comme dans les variantes précédentes, la fonction de ralentissement permettant une fermeture différée des deux clapets peut être obtenue par différents moyens pris isolément ou en combinaison à savoir : les raideurs différentes des deux ressorts de rappel des clapets, le frottement visqueux de la tige du clapet 13 dans la chambre-sas 9 et de façon générale l'amortissement de la tige dans l'huile et la conformation et les dimensions des composants hydrauliques.As in the previous variants, the slowdown function allowing closing delay of the two valves can be obtained by different means taken individually or in combination with know: the different stiffnesses of the two springs valve reminder, viscous friction of the rod of the valve 13 in the airlock chamber 9 and in general the damping of the rod in the oil and the conformation and dimensions of components Hydraulic.

Les modifications qui se traduisent par des changements de références sont les suivantes.Changes that result in Reference changes are as follows.

Le canal transversal 15 de l'entrée hydraulique 14 présente une dérivation 53 vers une chambre-tampon 54 située sous le piston-poussoir 30. De ce fait, cette chambre-tampon 54 ne possède plus de communication avec l'extérieur par un évent. Elle est reliée à l'entrée 14 et remplie d'huile sous pression. En conséquence le risque de corrosion qui provenait de sa communication constante avec l'extérieur est totalement éliminé.The transverse channel 15 of the inlet hydraulic 14 has a bypass 53 to a buffer chamber 54 located under the push piston 30. From this fact, this buffer chamber 54 no longer has any communication with the outside via a vent. She is connected to inlet 14 and filled with pressurized oil. Consequently the risk of corrosion which originated from its constant communication with the outside is totally eliminated.

Lors de la commande en descente de la tige du piston du vérin par le conduit 3, l'entrée 14 provenant de la ligne d'alimentation 55 de la chambre 6 du vérin à travers le dispositif selon l'invention se trouve reliée à la bâche en même temps que la chambre-tampon 54. Le déplacement commandé du piston-poussoir 30 vers le bas par la pression du fluide venant du conduit 3, provoque l'ouverture du clapet de sécurité 13 puis consécutivement, par exemple par la tige 23, après contact mécanique de poussée celle du clapet primaire 11.When ordering down the rod of the piston of the jack through the conduit 3, the inlet 14 coming of the supply line 55 of the chamber 6 of the jack through the device according to the invention is found connected to the cover at the same time as the buffer chamber 54. The controlled movement of the push piston 30 towards the bottom by the pressure of the fluid coming from the conduit 3, causes the safety valve 13 to open then consecutively, for example by the rod 23, after mechanical thrust contact that of the primary valve 11.

La remontée du piston-poussoir 30 est garantie par un ressort de rappel 56.The ascent of the plunger 30 is guaranteed by a return spring 56.

Un autre avantage de cette particularité concerne l'étanchéité. Les contraintes d'étanchéité sont moins importantes car les fuites alimentent les ligne du circuit hydraulique. La conséquence en est la possibilité de suppression de l'étanchéité entre la chambre-tampon 54 et l'arrivée du conduit 3 à la partie supérieure du piston-poussoir 30 d'une part et celle qui existait entre la tige supérieure 40 du clapet de sécurité 13 et la chambre-tampon 54 d'autre part.Another advantage of this feature relates to sealing. Sealing constraints are less important because the leaks feed the hydraulic circuit line. The consequence is possibility of removing the seal between the buffer chamber 54 and the arrival of conduit 3 to the part upper part of the piston 30 on the one hand and that which existed between the upper rod 40 of the valve security 13 and the buffer chamber 54 on the other hand.

Cet avantage augmente encore la fiabilité du dispositif.This advantage further increases the reliability of the device.

on expliquera ci-dessous le fonctionnement du dispositif de maintien selon l'invention en prenant comme exemple un vérin sous charge. Le fonctionnement sans charge se transpose aisément à partir de celui décrit.we will explain below how the holding device according to the invention by taking as an example a jack under load. The functioning without load easily transposes from that described.

Montée de la tige du vérin sous charge :Rise of the cylinder rod under load:

Le fluide moteur sous pression pénètre dans le bloc hydraulique 8 par les branches 15 et 53 vers le clapet de sécurité 13 et la chambre-tampon 54.The pressurized working fluid enters the hydraulic block 8 by the branches 15 and 53 towards the safety valve 13 and the buffer chamber 54.

Cette pression suffit à ouvrir en premier le clapet de sécurité 13 puis le clapet anti-retour primaire 11 pour alimenter le vérin par sa chambre 6 de sortie de sa tige 7.This pressure is enough to first open the safety valve 13 then the non-return valve primary 11 to supply the cylinder through its chamber 6 of out of its rod 7.

La tige 7 monte avec la charge qu'elle supporte jusqu'au niveau souhaité programmé ou non. La pression est alors coupée et la tige s'immobilise en position. Immédiatement après l'immobilisation, la charge provoque un retour d'huile pendant un temps court.Rod 7 rises with the load it supports up to the desired level programmed or not. The pressure is then cut and the rod comes to a standstill position. Immediately after immobilization, the load causes oil to return for a period of time short.

Le retour rapide d'huile participe au mouvement de retour de la bille du clapet primaire 11 qui vient s'appliquer contre son siège sous l'effet de la force de rappel élastique.The rapid return of oil contributes to return movement of the primary valve ball 11 which comes to apply against its seat under the effect of the elastic restoring force.

Dans le cas d'absence de charge, le clapet primaire il se ferme sous le seul effet de la force de rappel du ressort.In the case of no load, the valve primary it closes under the sole effect of the force of spring reminder.

Le clapet de sécurité 13 se ferme dans un deuxième temps dans la chambre-sas 9 en l'absence de pression en raison de l'isolation provenant de la fermeture préalable du clapet primaire 11. Cette fermeture en l'absence de pression dynamique et donc de débit ménage le joint du clapet de sécurité et évite à celui-ci de sortir de son logement.The safety valve 13 closes in a second time in room-airlock 9 in the absence of pressure due to insulation from the prior closing of the primary valve 11. This closing in the absence of dynamic pressure and therefore of flow protects the seal of the safety valve and avoids this one to come out of its housing.

Pour garantir cette succession ordonnée des fermetures, on peut jouer sur les différents facteurs déjà mentionnés ci-dessus à savoir : les raideurs différentes des deux ressorts de rappel des clapets, le frottement visqueux de la tige du clapet 13 dans la chambre-sas 9 et de façon générale l'amortissement de la tige dans l'huile et la conformation et les dimensions des composants hydrauliques.To guarantee this orderly succession of closures, we can play on the different factors already mentioned above, namely: stiffness different from the two valve return springs, the viscous friction of the valve stem 13 in the chamber-sas 9 and generally the amortization of the rod in the oil and the conformation and the dimensions of hydraulic components.

Dans la majorité des cas de montée de la tige sous charge, le débit de refoulement et la force de rappel sont suffisants pour que la bille 16 ferme le clapet primaire 11 avant le clapet de sécurité 13.In most cases of stem rise under load, the delivery rate and the force of recall are sufficient for ball 16 to close the primary valve 11 before the safety valve 13.

Maintien en position de la charge :Maintaining the load position:

La sécurité du maintien de la charge en position est garantie par les deux clapets anti-retour. Le clapet primaire 11 à bille 16 permet par sa fermeture le maintien immédiat de la charge.The security of maintaining the charge in position is guaranteed by the two non-return valves. The primary ball valve 11 allows 16 by its close immediate maintenance of the charge.

En fonctionnement normal la pression dans la chambre-sas 9 est faible.In normal operation the pressure in the room-lock 9 is weak.

En cas de défection ou de fuite du clapet primaire 11, si petite soit-elle, le maintien par ce seul clapet n'est plus garanti dans le temps. Cette dérive conduirait à un abaissement non volontaire de la charge, lent mais dangereux pour le chargement situé en dessous de la plate-forme maintenue par le vérin.If the valve fails or leaks primary 11, however small it may be, maintaining by this only one valve is no longer guaranteed over time. This drift would lead to an involuntary lowering of the charge, slow but dangerous for the load located in below the platform held by the jack.

La sécurité du maintien est apportée par le clapet de sécurité 13.Maintaining security is provided by the safety valve 13.

Réalisé avec un joint 51 non soumis au moment de sa fermeture à un débit important préjudiciable à sa tenue, l'étanchéité procurée par le clapet de sécurité est de haute fiabilité.Made with a seal 51 not submitted at the time of its closure at a significant flow detrimental to its the tightness provided by the safety valve is of high reliability.

La charge restera en position pratiquement indéfiniment.The load will remain in position practically indefinitely.

Descente de la tige sous charge :Lowering the rod under load:

La commande de descente de la tige 7 du vérin sous charge nécessite l'ouverture des deux clapets. La force provoquant l'ouverture est donnée par une pression de commande. Celle-ci peut être la pression s'exerçant sur l'autre chambre du vérin à double effet ou une pression indépendante de commande ou de pilotage.The control for lowering the rod 7 of the jack under load requires the opening of the two valves. The force causing the opening is given by a control pressure. This can be the pressure acting on the other chamber of the double-acting cylinder or an independent control pressure or piloting.

Elle s'exerce d'abord sur le piston-poussoir 30 dont le déplacement engendre celui du corps du clapet par contact du piston-poussoir 30 avec l'extrémité de la prolongation supérieure 40 de la tige du clapet de sécurité 13 et par poussée mécanique de translation.It is exerted first on the push-piston 30 whose displacement generates that of the body of the valve by contact of the push-piston 30 with the end of the upper extension 40 of the rod of the safety valve 13 and by mechanical pushing of translation.

La tige du clapet de sécurité continue à descendre. L'extrémité inférieure de sa tige 23 arrive en contact de poussée avec l'élément d'obturation du clapet primaire et en poursuivant sa course le contraint en ouverture.The safety valve stem continues to go down. The lower end of its rod 23 arrives in thrust contact with the shutter element of the primary valve and continuing its travel the constrained in opening.

on libère ainsi le passage du fluide sous pression vers le conduit 15 et l'entrée 14 qui se trouve reliée à la bâche. Ceci permet d'évacuer le fluide de la chambre 6 vers la bâche à travers la chambre-sas 9 et le conduit 15.thus freeing the passage of the fluid under pressure towards the conduit 15 and the inlet 14 which is is connected to the tarpaulin. This allows to evacuate the fluid from chamber 6 to the tarpaulin through the airlock 9 and duct 15.

Le clapet de sécurité étant en position ouverte, son joint ne risque pas de dégradation ou de sortie de son logement.The safety valve being in position open, its seal does not risk damage or leaving his home.

Arrêt de la descente de la tige sous charge :Stopping the lowering of the rod under load:

Si l'on coupe l'alimentation en fluide moteur sous pression en 3, la commande en ouverture des clapets n'est plus maintenue et on provoque de la même façon que ci-dessus un retard à la fermeture du clapet de sécurité 13 par rapport au clapet primaire 11. L'ensemble de l'équipage mobile dont le piston-poussoir 30 remonte.If the engine fluid supply is cut off under pressure in 3, the command to open the valves is no longer maintained and we cause the same way that above a delay in closing the valve safety device 13 with respect to the primary valve 11. All of the moving equipment, including the push piston 30 goes up.

Il est important de comprendre que l'on recherche dans cette invention une fermeture du clapet de sécurité sous faible débit d'huile de façon à éviter d'endommager ou de déloger le joint de ce clapet et garantir une grande fiabilité de fonctionnement.It is important to understand that search in this invention for closing the valve safety under low oil flow to avoid damage or dislodge the seal from this valve and guarantee high operating reliability.

La rentrée de la tige du vérin peut également résulter d'une ouverture autrement commandée des clapets c'est-à-dire indépendante de la pression motrice provoquant la rentrée de la tige.The retraction of the cylinder rod can also result from an otherwise ordered opening of valves i.e. independent of pressure driving causing the retraction of the rod.

Pour rentrer la tige on pourrait aussi utiliser la force de gravité provenant de la plate-forme chargée.To retract the rod we could also use the force of gravity coming from the platform loaded.

Il faut préciser ici que les perfectionnements de simplification décrits qui caractérisent la dernière variante s'appliquent aux variantes précédentes et que toutes les formes techniques de clapets sont possibles.It should be noted here that the described simplification enhancements which characterize the last variant apply to previous variants and that all forms valve techniques are possible.

Bien entendu, à branchement identique, le dispositif selon l'invention peut être orienté au montage dans le sens contraire de celui représenté sur les figures ou selon toute autre orientation de son support.Of course, with identical connection, the device according to the invention can be oriented at mounting in the opposite direction to that shown on the figures or according to any other orientation of his support.

Claims (22)

  1. A device for maintaining in position the cylinder shaft of a hydraulic cylinder (1), at least a single-effect cylinder, comprising a power chamber for example a shaft (7) outlet chamber (6) and a second chamber used as a shaft inlet chamber (5) and at least one closing spring biased anti-return valve (11) mounted in the supply circuit to one of the chambers, opening toward said chamber, said device comprising a hydraulic insulation block (2) through which this chamber is supplied, characterized in that:
    the anti-return valve (11), called the primary anti-return valve (11), is completed by a spring biased anti-return safety valve (13) separated from the primary valve (11) by a sluice-chamber (9), each of the primary anti-return valve and the safety valve being connected with one of the two extremity openings which facilitate supplying one of the hydraulic cylinder chambers, both valves (11, 13) being mounted opening in the direction in which power fluid flows toward this chamber;
       and characterized by:
    means for delayed closing of the safety valve (13) with respect to the primary valve (11) closing,
       and characterized by:
    means (30) to control opening of the safety valve (13), which opening causes the primary valve (11) opening.
  2. The device for maintaining in position the shaft of a hydraulic cylinder according to claim 1, characterized in that the means to control opening of the safety valve (13) is controlled by a control outside hydraulic insulation block (2).
  3. The device for maintaining in position the shaft of a hydraulic cylinder according to claim 1, characterized in that the means for delayed closing of the safety valve (13) with respect to the primary valve (11) closing is a delay means which slows the return course of the safety valve.
  4. The device for maintaining in position the shaft of a hydraulic cylinder according to claim 3, characterized in that the return travel of the safety valve is slowed down by a damping effect on an element integral with the safety valve body.
  5. The device for maintaining in position the shaft of a hydraulic cylinder according to the preceding claim, characterized in that the damping effect is obtained by oil laminar flow.
  6. The device for maintaining in position the shaft of a hydraulic cylinder according to claim 4, characterized in that the damping effect is obtained by a viscous contact with a portion of the shaft of the safety valve (13).
  7. The device for maintaining in position the shaft of a hydraulic cylinder according to claim 1, characterized in that the opening control of the primary valve (11) is a control link for opening which causes the opening of the primary valve (11) via the safety valve (13).
  8. The device for maintaining in position the shaft of a hydraulic cylinder according to the preceding claim, characterized in that the control transmission for opening the primary valve (11) includes transmission play which physically dissociates the two valves from one another.
  9. The device for maintaining in position the shaft of a hydraulic cylinder according to the preceding claim, characterized in that the control link for opening the primary valve (11) terminates in a shaft (23) integral with the safety valve (13) body, an extremity of this shaft being spaced from the primary valve (11) body to form play (25) therebetween when both valves are in a closed position.
  10. The device for maintaining in position the shaft of a hydraulic cylinder according to preceding claims 7 and 8, characterized in that the control link for opening the primary valve (11), via the safety valve (13), includes the delay means for delaying the closing of the safety valve (13) with respect to the primary valve (11) closing.
  11. The device for maintaining in position the shaft of a hydraulic cylinder according to any of the preceding claims 1 or 6 to 9, characterized in that the opening of the safety valve (13) is controlled by means of a pressure.
  12. The device for maintaining in position the shaft of a hydraulic cylinder according to the preceding claim, characterized in that the control pressure is the pressure which activates the other chamber of the hydraulic cylinder.
  13. The device for maintaining in position the shaft of a hydraulic cylinder according to the preceding claim, characterized in that the opening of the safety valve (13) is controlled by the pressure which activates the return of the cylinder shaft (7).
  14. The device for maintaining in position the shaft of a hydraulic cylinder according to claim 10, characterized in that the opening control connection and the delay means comprise a composite mechanical connection (29) formed of a series of elements which comprises a piston-button (30) subjected to controlling pressure, a counterweight connection (34) which is displaceable along a guide groove (35) via pushing contact with the piston-button (30), an end piston (40) formed of an end extremity of a shaft which constitutes an extension of the safety valve (13) body (20), said end piston (40) sliding with play within the same guide groove (35) as the counterweight (34), and characterized in that the counterweight (34) and the end piston (40) are separated in the guide groove (35) by a space which, together with a lateral wall of the guide groove (35), forms a reservoir-chamber (42) for oil, and characterized in that the piston-button (30), bearing on the counterweight (34), can move inside a chamber (32) that is open to the atmosphere and is subject to pressure from the fluid supplying the cylinder chamber opposite to the chamber supplied through the sluice (9).
  15. The device for maintaining in position the shaft of a hydraulic cylinder according to any preceding claim, characterized in that the safety valve (13) is a sealed valve (26).
  16. The device for maintaining in position the shaft of a hydraulic cylinder according to any preceding claim, characterized in that the chamber located beneath the piston-button (30) is a buffer chamber (54) filled with oil, insulated from atmosphere and connected to the power fluid inlet (14) by a shunt (53).
  17. The device for maintaining in position the shaft of a hydraulic cylinder according to claim 4, characterized in that the damping effect is provided by differences in rigidity features of the valves (11, 13).
  18. The device for maintaining in position the shaft of a hydraulic cylinder according to claim 4, characterized in that the damping effect is provided by differences in shape and dimensions of the hydraulic components.
  19. The device for maintaining in position the shaft of a hydraulic cylinder according to claim 4 or 17 or 18, characterized in that the damping effect results from a combined effect of hydraulic damping, differences in rigidity of the spring bias of the valves, and differences in shape and dimensions of the hydraulic components.
  20. The device for maintaining in position the shaft of a hydraulic cylinder according to any preceding claim, characterized in that the hydraulic cylinder is a single-effect cylinder.
  21. The device for maintaining in position the shaft of a hydraulic cylinder according to any preceding claim, characterized in that the safety valve (13) is actuated by any independent means, for example an electromechanical or electromagnetic means or any other means.
  22. The device for maintaining in position the shaft of a hydraulic cylinder according to any preceding claim, characterized in that a pressure sensor or detector (44) is coupled to the sluice (9), a detection and alarm circuit being operated by the excess of a reference pressure.
EP97913266A 1996-11-07 1997-11-06 Device for holding in position the rod of a pressure cylinder Expired - Lifetime EP0935715B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR9613778 1996-11-07
FR9613778A FR2755481B1 (en) 1996-11-07 1996-11-07 DEVICE FOR HOLDING IN POSITION AND UNDER LOAD OF A HYDRAULIC CYLINDER
PCT/FR1997/001994 WO1998020260A2 (en) 1996-11-07 1997-11-06 Device for holding in position the rod of a pressure cylinder

Publications (2)

Publication Number Publication Date
EP0935715A1 EP0935715A1 (en) 1999-08-18
EP0935715B1 true EP0935715B1 (en) 2004-01-21

Family

ID=9497542

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97913266A Expired - Lifetime EP0935715B1 (en) 1996-11-07 1997-11-06 Device for holding in position the rod of a pressure cylinder

Country Status (11)

Country Link
US (1) US5913810A (en)
EP (1) EP0935715B1 (en)
CN (1) CN1103411C (en)
AT (1) ATE258274T1 (en)
CA (1) CA2270579A1 (en)
DE (1) DE69727307T2 (en)
ES (1) ES2216132T3 (en)
FR (1) FR2755481B1 (en)
RU (1) RU2191298C2 (en)
UA (1) UA46875C2 (en)
WO (1) WO1998020260A2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3049663A1 (en) * 2016-03-31 2017-10-06 Lohr Ind DOUBLE-CLOSING SAFETY BLOCK FOR HYDRAULIC CYLINDER
DE102020109615A1 (en) 2020-04-07 2021-10-07 Neumeister Hydraulik Gmbh DEVICE FOR HOLDING A SHAFT OF A HYDRAULIC CYLINDER IN POSITION AND METHOD OF UNLOCKING AND LOCKING A SECONDARY CHECK VALVE OF THE DEVICE

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6935409B1 (en) 1998-06-08 2005-08-30 Thermotek, Inc. Cooling apparatus having low profile extrusion
WO2001092235A1 (en) 2000-06-01 2001-12-06 Bristol-Myers Squibb Pharma Company LACTAMS SUBSTITUTED BY CYCLIC SUCCINATES AS INHIBITORS OF Aβ PROTEIN PRODUCTION
US20060052821A1 (en) 2001-09-06 2006-03-09 Ovalis, Inc. Systems and methods for treating septal defects
US6702835B2 (en) 2001-09-07 2004-03-09 Core Medical, Inc. Needle apparatus for closing septal defects and methods for using such apparatus
US6776784B2 (en) 2001-09-06 2004-08-17 Core Medical, Inc. Clip apparatus for closing septal defects and methods of use
US9113577B2 (en) 2001-11-27 2015-08-18 Thermotek, Inc. Method and system for automotive battery cooling
US7108324B2 (en) * 2002-06-28 2006-09-19 Lear Corporation Vehicle seat adjuster
RU2358175C2 (en) * 2004-07-12 2009-06-10 Тифенбах Контрол Системс Гмбх Opened check valve
US8579936B2 (en) 2005-07-05 2013-11-12 ProMed, Inc. Centering of delivery devices with respect to a septal defect
EP1741936A1 (en) * 2005-07-08 2007-01-10 THOMAS MAGNETE GmbH Feed controlling valve for fluids
US7846179B2 (en) 2005-09-01 2010-12-07 Ovalis, Inc. Suture-based systems and methods for treating septal defects
ITMI20060426A1 (en) * 2006-03-10 2007-09-11 Faac Spa HANDLING SYSTEM WITH HYDRAULIC DOUBLE ACTING ACTUATOR FOR GATE HANDLING
TWM315185U (en) * 2006-12-15 2007-07-11 Wei-Te Hsu Vehicular hydraulic tank reverse safety device
US8262058B2 (en) * 2008-08-28 2012-09-11 Kot Norbert J Balanced pilot operated check valve
CN104105890B (en) * 2012-02-16 2016-02-24 克斯美库股份有限公司 With the cylinder assembly of servomechanism
US9611871B2 (en) 2013-09-13 2017-04-04 Norbert J. Kot Pneumatic valve assembly and method
CN104019080A (en) * 2014-06-23 2014-09-03 柳州柳工液压件有限公司 Oil supplement cylinder
EP3609692B1 (en) * 2017-08-01 2021-07-21 Moog GmbH Apparatus for controlling the switch over of hydraulic cylinders
WO2019030354A1 (en) * 2017-08-11 2019-02-14 Eaton Intelligent Power Limited Manifold with a load holding valve and a drain valve
EP3660365B1 (en) * 2018-11-27 2021-07-21 Hamilton Sundstrand Corporation Servo valve
DE102019218400A1 (en) * 2019-11-27 2021-05-27 Hawe Hydraulik Se Valve cone, load-holding valve with valve cone and method of assembling a check valve
FR3104653B1 (en) 2019-12-17 2021-11-19 Lohr Ind SAFETY BLOCK WITH SOLENOID VALVE FOR CYLINDER AND HYDRAULIC CIRCUIT CONTAINING SEVERAL CYLINDERS EQUIPPED WITH SUCH BLOCKS

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2702044A (en) * 1953-11-23 1955-02-15 Albert D Johnston Automatic supply and exhaust valve
US2797550A (en) * 1954-05-05 1957-07-02 Stelzer William Hydraulic elevators
US3381587A (en) * 1965-09-10 1968-05-07 Deere & Co Hydraulic control system
DE2036547C3 (en) * 1970-07-23 1973-10-31 Fried. Krupp Gmbh, 4300 Essen Braking and locking device for a hydrostatic drive
DE2305835A1 (en) * 1973-02-07 1974-08-15 Danfoss As HYDRAULIC CONTROL DEVICE, IN PARTICULAR STEERING DEVICE
WO1981000600A1 (en) * 1979-08-30 1981-03-05 Caterpillar Tractor Co Lock valve with variable length piston and hydraulic system for a work implement using the same
US4355565A (en) * 1980-03-24 1982-10-26 Caterpillar Tractor Co. Fluid circuit with zero leak load check and by-pass valve
IT213216Z2 (en) * 1987-05-15 1989-11-09 Oil Control Spa IMPROVEMENTS WITH HYDRAULIC CONTROL VALVE, IN PARTICULAR FOR HYDRAULIC CIRCUITS WITH DISTRIBUTOR EVEN WITH CLOSED CENTER
US4913190A (en) * 1989-04-24 1990-04-03 Deere & Company Detent mechanism for a control valve
SU1753068A1 (en) * 1990-06-07 1992-08-07 Московское станкостроительное производственное объединение "Красный пролетарий" Unilateral water lock
US5261456A (en) * 1992-11-02 1993-11-16 Deere & Company Transmission engagement override valve
NL1000038C2 (en) * 1995-04-04 1996-10-07 Applied Power Inc Hydraulic tilting device for a cabin.

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3049663A1 (en) * 2016-03-31 2017-10-06 Lohr Ind DOUBLE-CLOSING SAFETY BLOCK FOR HYDRAULIC CYLINDER
WO2017191380A1 (en) * 2016-03-31 2017-11-09 Lohr Industrie Dual-valve security unit for hydraulic cylinders
US10760595B2 (en) 2016-03-31 2020-09-01 Lohr Industrie Dual-valve security unit for hydraulic cylinders
DE102020109615A1 (en) 2020-04-07 2021-10-07 Neumeister Hydraulik Gmbh DEVICE FOR HOLDING A SHAFT OF A HYDRAULIC CYLINDER IN POSITION AND METHOD OF UNLOCKING AND LOCKING A SECONDARY CHECK VALVE OF THE DEVICE
WO2021204319A1 (en) 2020-04-07 2021-10-14 Neumeister Hydraulik Gmbh Device for holding a stem of a hydraulic cylinder in position, and method for unblocking and blocking a secondary check valve of the device

Also Published As

Publication number Publication date
DE69727307D1 (en) 2004-02-26
ATE258274T1 (en) 2004-02-15
ES2216132T3 (en) 2004-10-16
CN1103411C (en) 2003-03-19
UA46875C2 (en) 2002-06-17
EP0935715A1 (en) 1999-08-18
FR2755481A1 (en) 1998-05-07
FR2755481B1 (en) 1998-12-24
DE69727307T2 (en) 2004-11-18
RU2191298C2 (en) 2002-10-20
CN1244236A (en) 2000-02-09
US5913810A (en) 1999-06-22
CA2270579A1 (en) 1998-05-14
WO1998020260A2 (en) 1998-05-14
WO1998020260A3 (en) 2002-10-03

Similar Documents

Publication Publication Date Title
EP0935715B1 (en) Device for holding in position the rod of a pressure cylinder
CA2705344C (en) Mechanically operated actuator with hydraulic damping
FR2745873A1 (en) FIXING ELEMENT IN THE FORM OF A PISTON-CYLINDER UNIT, FOR EXAMPLE, FOR A VEHICLE TAILGATE
EP0296936B1 (en) Drive mechanism for fast and controlled separation of two coupled elements
EP0021977B1 (en) Hydraulic directional valve, especially for servocontrols in aeroplanes and helicopters
FR2516037A1 (en) IMPROVEMENTS TO HYDRAULIC ANTI-PIPING BRAKE SYSTEMS FOR VEHICLES
FR2518694A1 (en) HYDRAULICALLY CONTROLLED NON-RETURN VALVE, IN PARTICULAR FOR A REVERSE CONTROL DEVICE FOR HYDRAULIC TAPPING SUPPORT
EP2635518B1 (en) System for controlling a stabilising leg, stabilisation device, and vehicle including a stabilisation device
CA3106845A1 (en) Emergency opening device for an aircraft door, comprising a retaining member with a hook
EP0287434B1 (en) Differential hydraulic jack, with a damping device, for operating electric breakers
EP0459840B1 (en) Control device for a double acting hydraulic actuator
CA3185148A1 (en) Device for emergency opening of an aircraft door with peripheral retaining member
CA3106865A1 (en) Emergency opening device for an aircraft door, comprising a telescopic operating member
FR2547015A1 (en) ACTUATOR WITH PNEUMATIC ENERGY ACCUMULATOR, IN PARTICULAR FOR TAPS
FR2520473A1 (en) SAFETY VALVE AND CONTROL DEVICE THEREOF
FR2828463A1 (en) Automobile brake control valve allows rise of master cylinder liquid level by having first minimum flow section
FR2566352A1 (en) BRAKE EFFORT HYDRAULIC AMPLIFIER
FR2896725A1 (en) Vehicle wheel valve for controlling tire inflation has friction-less piston between housing and cover creating pressure and control chambers
FR2479358A1 (en) Mechanical digger lifting jack with safety device - monitors pressure after flexible pipeline section to control automatic non-return valve which can be selectively inhibited
FR2757223A1 (en) Hydraulic installation used e.g. for vehicle braking system
EP1598306A1 (en) Control device for the lowering of a hydraulic jack
FR2731418A1 (en) Process for detection and control of support loss of hydraulic loading platform
FR2694733A3 (en) Interconnection unit for tractor and trailer braking systems - has operating mode of both systems determined by connection or disconnection of trailer and by hand-brake position
FR2674237A1 (en) Valve for limiting the load which can be lifted by a pneumatic lifting machine
FR2648773A1 (en) Emergency braking device

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19990426

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: LOHR ACTIVITES

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: LOHR INDUSTRIE

17Q First examination report despatched

Effective date: 20010921

D17D Deferred search report published (deleted)
GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040121

Ref country code: IE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040121

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040121

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040121

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: FRENCH

REF Corresponds to:

Ref document number: 69727307

Country of ref document: DE

Date of ref document: 20040226

Kind code of ref document: P

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040421

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040421

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040421

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 20040517

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
REG Reference to a national code

Ref country code: IE

Ref legal event code: FD4D

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2216132

Country of ref document: ES

Kind code of ref document: T3

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20041106

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20041130

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20041130

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20041130

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20041130

26N No opposition filed

Effective date: 20041022

BERE Be: lapsed

Owner name: *LOHR INDUSTRIE

Effective date: 20041130

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

BERE Be: lapsed

Owner name: *LOHR INDUSTRIE

Effective date: 20041130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040621

REG Reference to a national code

Ref country code: FR

Ref legal event code: GC

Effective date: 20120924

REG Reference to a national code

Ref country code: FR

Ref legal event code: RG

Effective date: 20121122

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 19

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20161126

Year of fee payment: 20

Ref country code: FR

Payment date: 20161124

Year of fee payment: 20

Ref country code: GB

Payment date: 20161121

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20161116

Year of fee payment: 20

Ref country code: ES

Payment date: 20161130

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 69727307

Country of ref document: DE

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Expiry date: 20171105

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20171105

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20180508

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20171107