EP0296047A1 - Multi-stage actuator with at least three sliding elements and telescopic jib incorporating this actuator - Google Patents

Multi-stage actuator with at least three sliding elements and telescopic jib incorporating this actuator Download PDF

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Publication number
EP0296047A1
EP0296047A1 EP88401457A EP88401457A EP0296047A1 EP 0296047 A1 EP0296047 A1 EP 0296047A1 EP 88401457 A EP88401457 A EP 88401457A EP 88401457 A EP88401457 A EP 88401457A EP 0296047 A1 EP0296047 A1 EP 0296047A1
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EP
European Patent Office
Prior art keywords
section
piston
cylinder
chamber
piston rod
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Granted
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EP88401457A
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German (de)
French (fr)
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EP0296047B1 (en
Inventor
Robert Baraniak
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PPM SA
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PPM SA
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
    • B66C23/62—Constructional features or details
    • B66C23/64—Jibs
    • B66C23/70—Jibs constructed of sections adapted to be assembled to form jibs or various lengths
    • B66C23/701—Jibs constructed of sections adapted to be assembled to form jibs or various lengths telescopic
    • B66C23/705—Jibs constructed of sections adapted to be assembled to form jibs or various lengths telescopic telescoped by hydraulic jacks
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
    • F15B15/16—Characterised by the construction of the motor unit of the straight-cylinder type of the telescopic type

Definitions

  • FR-A-2 345 608 describes such a jack.
  • the fluid supply and exhaust pipes of this cylinder are connected to the larger diameter cylinder.
  • the object of the invention is therefore firstly to specify the arrangements which allow these preferred embodiments to be obtained and which are defined in the characterizing part of claim 1.
  • the jack comprises a fifth conduit, which is contained in the piston rod, which opens into the second large chamber and which is connected to a selective device for supplementing the supply of pressurized fluid;
  • the selective device supplemental feeding pressurized fluid is constituted by a two-position fluid distributor, a connecting conduit, which connects the two-position fluid distributor which is connected to said connecting conduit and the second conduit supply supplement, which connects said two-position fluid distributor to said fifth conduit, the two positions of the two-position fluid distributor corresponding, the first position, to the closure of the supply complement conduit, and, the second position, when the connecting duct is placed in communication with the supply complement duct;
  • the two-position fluid distributor includes an electromagnetic device for adjusting its position which is connected to one of the electrical terminals of a pressure switch, which is itself connected to said supply complement duct;
  • the actuator comprises a calibrated relief valve connected in bypass to said fifth conduit.
  • the invention also more particularly relates to a telescopic boom comprising a first internal section, a second intermediate section, inside which the first section is slidably mounted, and a third section, external, inside. which the second section is slidably mounted, while a cylinder as described above is mounted therein, longitudinally inside the three said sections, the first cylinder being integral with the first section, the second cylinder being integral with the second section and the piston rod being integral with the third section.
  • the first cylinder is fixed on the internal end of the first section
  • the second cylinder is fixed on the internal end of the second section
  • the piston rod is fixed on the part of the third section, which is opposite to the axial opening of this third section through which the second section penetrates.
  • the main advantage of the invention lies in the possibility of obtaining simultaneous displacements and at equal relative speeds of the elements of the jack, and of the boom sections, without having to resort to complicated, heavy, expensive and fragile mechanical assemblies.
  • the jack shown in the figure includes: - A first cylinder 1 comprising at each end a bottom 2, 3; - A first piston 4, which is slidably mounted inside the first cylinder 1 and which delimits there, in cooperation with the bottom 2, a first large chamber 5 of large useful section S5, and, in cooperation with the bottom 3, a first small chamber 6 of small useful section S6 (less than the useful section S5); - A second cylinder 7 which comprises, at one end, a bottom formed by the first piston 4 and, at the other end, a bottom 8 which is integral with the first piston 4, and which crosses with seal 3b the bottom 3 of the first cylinder 1 which, in cooperation with the first piston 4, delimits the first small useful chamber 6; - A second piston 9, which is slidably mounted inside the second cylinder 7 and which delimits there, in cooperation with the first piston 4, a second large chamber 10 of large useful section S10, and, in cooperation with the bottom 8 of the second cylinder, a second small chamber 11 of small useful section S11 (less than the useful
  • the second conduit 16 and the third conduit 18 open to the outside of the piston rod 12 by fittings 20, 21, respectively.
  • the cylinder supply circuit is itself constituted by: - a fluid reservoir 22; - a pump 23; - a three-position distributor 24; - a calibrated relief valve 25; - The suction pipe 26 and the discharge pipe 27 of the pump 23, which connect it to the tank 22 and to the distributor 24, respectively; - conduits 28 and 29, which connect the distributor 24 to the connections 20, 21, respectively; - A conduit 30, which connects the distributor 24 to the reservoir 22; and a duct 31 which connects the discharge duct 27 to the reservoir 22 and on which the calibrated relief valve 25 is placed.
  • the three positions of the distributor 24 correspond: - The first position, when the conduits 27 and 28 are put into communication, and the conduits 29 and 30; - The second position, to close the conduits 28 and 29, and to connect the conduits 27 and 30; and - the third position, when the conduits 27 and 29 are put into communication, and the conduits 28 and 30.
  • a circuit for adjusting the volume of fluid contained in the chambers 10 and 6 is also provided and consists of: - A fifth conduit 42, internal to the piston rod 12, which opens into the second large chamber 10 and connects it to an external connector 43; - A two-position fluid distributor 44, provided with an electromagnetic device 45 for adjusting its position, the effect of which, when energized, is antagonistic to that of a return spring 46; - A pressure switch 47 with two electrical terminals 48, 49, a hydraulic connection 50 and a return spring 51 with an effect antagonistic to that of the pressurized fluid contained in the hydraulic connection 50; - an electric earth 52; - a calibrated relief valve 53; - A connecting duct 54, connecting the two-position fluid distributor 44 to the duct 28; - a supply complement duct 55, connecting the fluid distributor in two positions to the external connector 43; - A conduit 56, connecting the additional supply conduit 55 to the fluid reservoir 22, the calibrated relief valve 53 being disposed on this conduit 56; - A conduit 57, connecting the hydraulic connection 50 of the pressure
  • the setting of the relief valve 53 is higher, for example by 20 bars, than that of the pressure switch 47, and is equal to 350 bars, that of the pressure switch being equal to 330 bars. This implies that, as long as the pressure in the conduit 57 is greater than 330 bars, the pressure switch 47 does not make the electrical connection between its terminals 48 and 49, and the electromagnetic device 45 is not energized, so that, under the unique effect of the spring 46, the fluid distributor 44 is placed in its first position.
  • This fluid distributor 44 corresponds: - The first position, to the obturations of the connection duct 54 and the supply complement duct 55; and - the second position, when the connecting pipe 54 and the additional supply pipe 55 are placed in communication.
  • the jack which has just been described, is placed inside a telescopic boom with three sections, the axis 32 of the jack substantially coinciding with the axis of this arrow.
  • This consists of a first internal section 33, a second intermediate section 34 and a third external section 35, slidably mounted, the first section 33 inside the second section 34, into which it enters through an opening 34a, and the second section 34 inside the third section 35, into which it enters through an opening 35a.
  • Sliding members, rollers or sliding pads make these sliding possible.
  • these are rollers 36 and 37, mounted inside the second section 34 and the third section 35, respectively, near their respective openings, and rollers 38 and 39, mounted at the 'outside of the first section 33 and the second section 34, respectively, near their respective bottoms, opposite the openings 33a and 34a of these sections.
  • first (1) and second (7) cylinders are extended by sails, which are fixed (3a, 8a) to the internal ends of the first (33) and second (34) sections of the boom telescopic and constitute the bottoms of these respective sections.
  • the third section 35 is closed by a bottom 40, on which is fixed (41) the end of the piston rod 12.
  • the section S10 of the second large chamber 10 is, in the embodiment described, equal to the section S6 of the first small chamber 6. Because these two chambers are in permanent communication with one another, and with no other chamber, the volume of fluid which leaves one of these two chambers (or which enters it) is necessarily received in the other chamber (or leaves it).
  • sections S10 and S6 are equal, this implies that the second cylinder 7 moves with respect to the second piston 9 at the same speed and simultaneously with the movement of the first cylinder 1 with respect to the first piston 4.
  • the relative strokes C33 / 34 and C34 / 35 of the first section 33 relative to the second section 34, and of the second section 34 relative to the third section 35 are also equal.
  • the sum of the volumes of the first small chamber 6 and the second large chamber 10 was assumed to be constant. In reality, inevitable leaks cause slight variations in the value of this sum of volumes, and it is often necessary to supplement the quantity of fluid contained in these chambers, or, on the contrary, to allow an evacuation of excess fluid. This complement or this evacuation of fluid is carried out automatically in the following manner.
  • the three-position distributor 24 is assumed to have been placed in its first position.
  • the pressure of this fluid decreases and becomes lower than the setting pressure of the pressure switch 47, which causes the electrical connection between the two terminals 48, 49 and, consequently , the supply of electrical energy to the electromagnetic device 45, which places the fluid distributor in two positions 44 in its second position.
  • the pressure of this fluid increases until reaching the value of the setting pressure of the relief valve 53: by means of this relief valve 53, the maximum pressure in the second large chamber 10 is limited to a value making it possible to prohibit any deterioration of the jack.
  • the actual telescoping control is as follows: - For the output of the sections relative to each other, and the extension of the arrow, the distributor 24 is placed in its first position: the fluid discharged by the pump 23 fills the first large chamber 5; the first piston 4 approaches the bottom 3 of the first cylinder 1; the fluid contained in the first small chamber 6 is driven out of this chamber and will fill the second large chamber 10; the second piston 9 approaches the bottom 8 of the second cylinder 7; and the fluid contained in the second small chamber 11 is expelled therefrom and, through the fourth 19 and third conduits 18, and the conduit 29, returns to the reservoir 22; - for the return of the various sections and the retraction of the boom, the installation of the distributor 24 in its third position causes the reverse displacements of those described with regard to the exit of these sections.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Actuator (AREA)
  • Jib Cranes (AREA)

Abstract

The invention relates to a multi-stage actuator with at least three elements mounted so as to slide relative to each other, comprising one first piston (4), slidably mounted in a first cylinder (1) where it defines a first large chamber (5) and a first small chamber (6); one second piston (9) slidably mounted in a second cylinder (7) integral with the first piston (4) where it delimits a second large chamber (10) and a second small chamber (11); one piston rod (12) fixed to the second piston (9); one first passage (13) providing permanent communication between the first small chamber (6) and the second large chamber (10); and two pipe couplings (20, 21) to two external pipes (28, 29) connected to a fluid delivery device (23) and a fluid outflow (22). The pipe couplings (20, 21) are placed on the piston rod (12); and the first large chamber (5) is connected to one (20) of the two pipe couplings by a first pipe (14) fixed to the first piston (4), leading to the first large chamber (5) and mounted for sealed telescopic sliding relative to a second pipe (16) fixed to the second piston (9), leading into the second large chamber (10) and positioned inside the piston rod (12), the second small chamber (11) being connected to the other pipe coupling (21) by a third pipe (18) formed in the piston rod (12) and leading into the second small chamber (11). One application is the construction of a telescopic crane jib. <IMAGE>

Description

On connaît déjà des vérins multiples à au moins trois éléments montés coulissants les uns par rapport aux autres, tel celui défini dans le préambule de la revendication 1 de la présente demande de brevet.There are already known multiple jacks with at least three elements slidably mounted relative to one another, such as that defined in the preamble of claim 1 of this patent application.

FR-A-2 345 608 décrit un tel vérin. Les conduits d'ali­mentation et d'échappement de fluide de ce vérin sont raccordés au cylindre de plus grand diamètre. Pour certaines applications, il est cependant préférable de réaliser les alimentation et échappe­ment à partir de la tige de piston solidaire du piston de plus petit diamètre.FR-A-2 345 608 describes such a jack. The fluid supply and exhaust pipes of this cylinder are connected to the larger diameter cylinder. For certain applications, it is however preferable to produce the supply and exhaust from the piston rod integral with the piston of smaller diameter.

L'invention a donc d'abord pour objet de préciser les dispositions qui permettent l'obtention de ces réalisations pré­férées et qui sont définies dans la partie caractérisante de la revendication 1.The object of the invention is therefore firstly to specify the arrangements which allow these preferred embodiments to be obtained and which are defined in the characterizing part of claim 1.

Les avantageuses dispositions suivantes sont en outre préférentiellement adoptées :
    - le vérin comporte un cinquième conduit, qui est contenu dans la tige de piston, qui débouche dans la deuxième grande chambre et qui est raccordé à un dispositif sélectif de complément d'alimentation en fluide sous pression ;
    - le dispositif sélectif de complément d'alimentation en fluide sous pression est constitué par un distributeur de fluide à deux positions, un conduit de liaison, qui relie ce distributeur de fluide à deux positions audit raccord auquel est relié le deuxième conduit et un conduit de complément d'alimentation, qui relie ledit distributeur de fluide à deux positions audit cinquième conduit, les deux positions du distributeur de fluide à deux posi­tions correspondant, la première position, à l'obturation du conduit de complément d'alimentation, et, la deuxième position, à la mise en communication du conduit de liaison avec le conduit de complément d'alimentation ;
    - le distributeur de fluide à deux positions comporte un dispositif électromagnétique de réglage de sa position qui est relié à l'une des bornes électriques d'un manocontact, qui est lui-­même relié audit conduit de complément d'alimentation ;
    - le vérin comporte un clapet de décharge taré relié en dérivation audit cinquième conduit.The following advantageous arrangements are also preferably adopted:
- The jack comprises a fifth conduit, which is contained in the piston rod, which opens into the second large chamber and which is connected to a selective device for supplementing the supply of pressurized fluid;
- the selective device supplemental feeding pressurized fluid is constituted by a two-position fluid distributor, a connecting conduit, which connects the two-position fluid distributor which is connected to said connecting conduit and the second conduit supply supplement, which connects said two-position fluid distributor to said fifth conduit, the two positions of the two-position fluid distributor corresponding, the first position, to the closure of the supply complement conduit, and, the second position, when the connecting duct is placed in communication with the supply complement duct;
- the two-position fluid distributor includes an electromagnetic device for adjusting its position which is connected to one of the electrical terminals of a pressure switch, which is itself connected to said supply complement duct;
- The actuator comprises a calibrated relief valve connected in bypass to said fifth conduit.

L'invention a également, plus particulièrement, pour objet une flèche télescopique comportant un premier tronçon, interne, un deuxième tronçon, intermédiaire, à l'intérieur duquel le premier tronçon est monté coulissant, et un troisième tronçon, externe, à l'intérieur duquel le deuxième tronçon est monté coulis­sant, cependant qu'un vérin tel que décrit précédemment y est monté, longitudinalement à l'intérieur des trois dits tronçons, le premier cylindre étant solidaire du premier tronçon, le deuxième cylindre étant solidaire du deuxième tronçon et la tige de piston étant solidaire du troisième tronçon.The invention also more particularly relates to a telescopic boom comprising a first internal section, a second intermediate section, inside which the first section is slidably mounted, and a third section, external, inside. which the second section is slidably mounted, while a cylinder as described above is mounted therein, longitudinally inside the three said sections, the first cylinder being integral with the first section, the second cylinder being integral with the second section and the piston rod being integral with the third section.

De manière préférée, le premier cylindre est fixé sur l'extrémité interne du premier tronçon, le deuxième cylindre est fixé sur l'extrémité interne du deuxième tronçon et la tige de piston est fixée sur la partie du troisième tronçon, qui est opposée à l'ouverture axiale de ce troisième tronçon par laquelle pénètre le deuxième tronçon.Preferably, the first cylinder is fixed on the internal end of the first section, the second cylinder is fixed on the internal end of the second section and the piston rod is fixed on the part of the third section, which is opposite to the axial opening of this third section through which the second section penetrates.

L'avantage principal de l'invention réside dans la possi­bilité d'obtenir des déplacements simultanés et à vitesses rela­tives égales des éléments du vérin, et des tronçons de flèche, sans avoir recours à des montages mécaniques compliqués, lourds, coûteux et fragiles.The main advantage of the invention lies in the possibility of obtaining simultaneous displacements and at equal relative speeds of the elements of the jack, and of the boom sections, without having to resort to complicated, heavy, expensive and fragile mechanical assemblies.

L'invention sera mieux comprise, et des caractéristiques secondaires et leurs avantages apparaîtront au cours de la descrip­tion d'une réalisation donnée ci-dessous à titre d'exemple.The invention will be better understood, and secondary characteristics and their advantages will appear during the description of an embodiment given below by way of example.

Il est entendu que la description et le dessin ne sont donnés qu'à titre indicatif et non limitatif.It is understood that the description and the drawing are given for information only and are not limiting.

Il sera fait référence au dessin annexé, dans lequel la figure unique est une coupe axiale schématique d'un vérin et d'une flèche télescopique conformes à l'invention.Reference will be made to the accompanying drawing, in which the single figure is a schematic axial section of a jack and a telescopic boom in accordance with the invention.

Le vérin représenté sur la figure comprend :
    - un premier cylindre 1 comportant à chaque extrémité un fond 2, 3 ;
    - un premier piston 4, qui est monté coulissant à l'inté­rieur du premier cylindre 1 et qui y délimite, en coopération avec le fond 2, une première grande chambre 5 de grande section utile S5, et, en coopération avec le fond 3, une première petite chambre 6 de petite section utile S6 (inférieure à la section utile S5) ;
    - un deuxième cylindre 7 qui comporte, à une extrémité, un fond constitué par le premier piston 4 et, à l'autre extrémité, un fond 8 qui est solidaire du premier piston 4, et qui traverse avec étanchéité 3b le fond 3 du premier cylindre 1 qui, en coopé­ration avec le premier piston 4, délimite la première petite chambre utile 6 ;
    - un deuxième piston 9, qui est monté coulissant à l'intérieur du deuxième cylindre 7 et qui y délimite, en coopéra­tion avec le premier piston 4, une deuxième grande chambre 10 de grande section utile S10, et, en coopération avec le fond 8 du deuxième cylindre, une deuxième petite chambre 11 de petite section utile S11 (inférieure à la section utile S10) ;
    - une tige de piston 12, qui est solidaire du deuxième piston 9 et qui traverse avec étanchéité 8b le fond 8 du deuxième cylindre, qui, en coopération avec le deuxième piston 9, délimite la deuxième petite chambre 11 ;
    - un premier passage 13, qui est ménagé dans le premier piston 4 et qui réalise la communication permanente de la deuxième grande chambre 10 avec la première petite chambre 6 ;
    - un deuxième passage, constitué par un premier conduit 14, solidaire du premier piston 4, traversant ce premier piston (trou 15) et débouchant ainsi dans la première grande chambre 5, et par un deuxième conduit 16, solidaire du deuxième piston 9, contenu dans la tige de piston 12, traversant ce deuxième piston (trou 17) et débouchant dans la deuxième grande chambre 10, le premier conduit 14 coulissant avec étanchéité 17b à l'intérieur dudit deuxième conduit 16 ; et
    - un troisième passage, qui est constitué par un troi­sième conduit 18, ménagé à l'intérieur de la tige de piston 12, et par un quatrième conduit 19, ménagé dans le deuxième piston 9 et reliant en permanence le troisième conduit 18 à la deuxième petite chambre 11.The jack shown in the figure includes:
- A first cylinder 1 comprising at each end a bottom 2, 3;
- A first piston 4, which is slidably mounted inside the first cylinder 1 and which delimits there, in cooperation with the bottom 2, a first large chamber 5 of large useful section S5, and, in cooperation with the bottom 3, a first small chamber 6 of small useful section S6 (less than the useful section S5);
- A second cylinder 7 which comprises, at one end, a bottom formed by the first piston 4 and, at the other end, a bottom 8 which is integral with the first piston 4, and which crosses with seal 3b the bottom 3 of the first cylinder 1 which, in cooperation with the first piston 4, delimits the first small useful chamber 6;
- A second piston 9, which is slidably mounted inside the second cylinder 7 and which delimits there, in cooperation with the first piston 4, a second large chamber 10 of large useful section S10, and, in cooperation with the bottom 8 of the second cylinder, a second small chamber 11 of small useful section S11 (less than the useful section S10);
- A piston rod 12, which is integral with the second piston 9 and which crosses with seal 8b the bottom 8 of the second cylinder, which, in cooperation with the second piston 9, defines the second small chamber 11;
- A first passage 13, which is formed in the first piston 4 and which carries out the permanent communication of the second large chamber 10 with the first small chamber 6;
- A second passage, constituted by a first conduit 14, integral with the first piston 4, passing through this first piston (hole 15) and thus opening into the first large chamber 5, and by a second conduit 16, integral with the second piston 9, contained in the piston rod 12, passing through this second piston (hole 17) and opening into the second large chamber 10, the first conduit 14 sliding with seal 17b inside said second conduit 16; and
- A third passage, which is constituted by a third conduit 18, formed inside the piston rod 12, and by a fourth conduit 19, formed in the second piston 9 and permanently connecting the third conduit 18 to the second small room 11.

Le deuxième conduit 16 et le troisième conduit 18 débouchent à l'extérieur de la tige de piston 12 par des raccords 20, 21, respectivement.The second conduit 16 and the third conduit 18 open to the outside of the piston rod 12 by fittings 20, 21, respectively.

Le circuit d'alimentation du vérin est lui-même constitué par :
    - un réservoir de fluide 22 ;
    - une pompe 23 ;
    - un distributeur à trois positions 24 ;
    - un clapet de décharge taré 25 ;
    - le conduit d'aspiration 26 et le conduit de refoulement 27 de la pompe 23, qui la relient au réservoir 22 et au distribu­teur 24, respectivement ;
    - des conduits 28 et 29, qui relient le distributeur 24 aux raccords 20, 21, respectivement ;
    - un conduit 30, qui relie le distributeur 24 au réser­voir 22 ; et
    - un conduit 31, qui relie le conduit de refoulement 27 au réservoir 22 et sur lequel est placé le clapet de décharge taré 25.The cylinder supply circuit is itself constituted by:
- a fluid reservoir 22;
- a pump 23;
- a three-position distributor 24;
- a calibrated relief valve 25;
- The suction pipe 26 and the discharge pipe 27 of the pump 23, which connect it to the tank 22 and to the distributor 24, respectively;
- conduits 28 and 29, which connect the distributor 24 to the connections 20, 21, respectively;
- A conduit 30, which connects the distributor 24 to the reservoir 22; and
a duct 31 which connects the discharge duct 27 to the reservoir 22 and on which the calibrated relief valve 25 is placed.

Les trois positions du distributeur 24 correspondent :
    - la première position, aux mises en communication des conduits 27 et 28, et des conduits 29 et 30 ;
    - la deuxième position, à l'obturation des conduits 28 et 29, et à la mise en communication des conduits 27 et 30 ; et
    - la troisième position, aux mises en communication des conduits 27 et 29, et des conduits 28 et 30.The three positions of the distributor 24 correspond:
- The first position, when the conduits 27 and 28 are put into communication, and the conduits 29 and 30;
- The second position, to close the conduits 28 and 29, and to connect the conduits 27 and 30; and
- the third position, when the conduits 27 and 29 are put into communication, and the conduits 28 and 30.

Un circuit de réglage du volume de fluide contenu dans les chambres 10 et 6 est également prévu et est constitué par :
    - un cinquième conduit 42, interne à la tige de piston 12, qui débouche dans la deuxième grande chambre 10 et la relie à un raccord extérieur 43 ;
    - un distributeur de fluide à deux positions 44, muni d'un dispositif électromagnétique 45 de réglage de sa position, dont l'effet, lorsqu'il est excité, est antagoniste de celui d'un ressort de rappel 46 ;
    - un manocontact 47 à deux bornes électriques 48, 49, à un raccord hydraulique 50 et à un ressort de rappel 51 d'effet antagoniste de celui du fluide sous pression contenu dans le raccord hydraulique 50 ;
    - une terre électrique 52 ;
    - un clapet de décharge taré 53 ;
    - un conduit de liaison 54, reliant le distributeur de fluide à deux positions 44 au conduit 28 ;
    - un conduit de complément d'alimentation 55, reliant le distributeur de fluide à deux positions au raccord extérieur 43 ;
    - un conduit 56, reliant le conduit de complément d'ali­mentation 55 au réservoir de fluide 22, le clapet de décharge taré 53 étant disposé sur ce conduit 56 ;
    - un conduit 57, reliant le raccord hydraulique 50 du manocontact 47 au conduit de complément d'alimentation 55 ;
    - une liaison électrique 58 reliant la borne 48 du manocontact 47 au dispositif électromagnétique 45 ;
    - une liaison électrique 59 reliant l'autre borne 49 du manocontact 47 à la borne positive (+) d'une source d'énergie élec­trique 60 ; et
    - une liaison électrique 61 reliant la borne négative (-) de la source d'énergie électrique 60 à la terre électrique 52.A circuit for adjusting the volume of fluid contained in the chambers 10 and 6 is also provided and consists of:
- A fifth conduit 42, internal to the piston rod 12, which opens into the second large chamber 10 and connects it to an external connector 43;
- A two-position fluid distributor 44, provided with an electromagnetic device 45 for adjusting its position, the effect of which, when energized, is antagonistic to that of a return spring 46;
- A pressure switch 47 with two electrical terminals 48, 49, a hydraulic connection 50 and a return spring 51 with an effect antagonistic to that of the pressurized fluid contained in the hydraulic connection 50;
- an electric earth 52;
- a calibrated relief valve 53;
- A connecting duct 54, connecting the two-position fluid distributor 44 to the duct 28;
- a supply complement duct 55, connecting the fluid distributor in two positions to the external connector 43;
- A conduit 56, connecting the additional supply conduit 55 to the fluid reservoir 22, the calibrated relief valve 53 being disposed on this conduit 56;
- A conduit 57, connecting the hydraulic connection 50 of the pressure switch 47 to the supply complement conduit 55;
- an electrical connection 58 connecting the terminal 48 of the pressure switch 47 to the electromagnetic device 45;
- an electrical connection 59 connecting the other terminal 49 of the pressure switch 47 to the positive (+) terminal of an electrical energy source 60; and
- an electrical connection 61 connecting the negative (-) terminal of the electrical energy source 60 to the electrical ground 52.

Le tarage du clapet de décharge 53 est supérieur, par exemple de 20 bars, à celui du manocontact 47, et est égal à 350 bars, celui du manocontact étant égal à 330 bars. Ceci implique que, tant que la pression dans le conduit 57 est supérieure à 330 bars, le manocontact 47 ne réalise pas la liaison électrique entre ses bornes 48 et 49, et le dispositif électromagnétique 45 n'est pas excité, de sorte que, sous l'effet unique du ressort 46, le distributeur de fluide 44 est placé dans sa première position.The setting of the relief valve 53 is higher, for example by 20 bars, than that of the pressure switch 47, and is equal to 350 bars, that of the pressure switch being equal to 330 bars. This implies that, as long as the pressure in the conduit 57 is greater than 330 bars, the pressure switch 47 does not make the electrical connection between its terminals 48 and 49, and the electromagnetic device 45 is not energized, so that, under the unique effect of the spring 46, the fluid distributor 44 is placed in its first position.

Les deux positions de ce distributeur de fluide 44 correspondent :
    - la première position, aux obturations du conduit de liaison 54 et du conduit de complément d'alimentation 55 ; et
    - la deuxième position, à la mise en communication du conduit de liaison 54 et du conduit de complément d'alimenta­tion 55.The two positions of this fluid distributor 44 correspond:
- The first position, to the obturations of the connection duct 54 and the supply complement duct 55; and
- the second position, when the connecting pipe 54 and the additional supply pipe 55 are placed in communication.

Par ailleurs, le vérin, qui vient d'être décrit, est placé à l'intérieur d'une flèche télescopique à trois tronçons, l'axe 32 du vérin coïncidant sensiblement avec l'axe de cette flèche.Furthermore, the jack, which has just been described, is placed inside a telescopic boom with three sections, the axis 32 of the jack substantially coinciding with the axis of this arrow.

Celle-ci est constituée par un premier tronçon interne 33, un deuxième tronçon intermédiaire 34 et un troisième tronçon externe 35, montés coulissants, le premier tronçon 33 à l'intérieur du deuxième tronçon 34, dans lequel il pénètre par une ouverture 34a, et le deuxième tronçon 34 à l'intérieur du troisième tronçon 35, dans lequel il pénètre par une ouverture 35a. Des organes de coulissement, galets ou patins de glissement, rendent possibles ces coulissements. Il s'agit, dans la réalisation décrite, des galets 36 et 37, montés à l'intérieur du deuxième tronçon 34 et du troi­sième tronçon 35, respectivement, à proximité de leurs ouvertures respectives, et des galets 38 et 39, montés à l'extérieur du premier tronçon 33 et du deuxième tronçon 34, respectivement, à proximité de leurs fonds respectifs, opposés aux ouvertures 33a et 34a de ces tronçons.This consists of a first internal section 33, a second intermediate section 34 and a third external section 35, slidably mounted, the first section 33 inside the second section 34, into which it enters through an opening 34a, and the second section 34 inside the third section 35, into which it enters through an opening 35a. Sliding members, rollers or sliding pads, make these sliding possible. In the embodiment described, these are rollers 36 and 37, mounted inside the second section 34 and the third section 35, respectively, near their respective openings, and rollers 38 and 39, mounted at the 'outside of the first section 33 and the second section 34, respectively, near their respective bottoms, opposite the openings 33a and 34a of these sections.

A noter que les fonds 3 et 8 des premier (1) et deuxième (7) cylindres sont prolongés par des voiles, qui sont fixés (3a, 8a) aux extrémités internes des premier (33) et deuxième (34) tronçons de la flèche télescopique et constituent les fonds de ces tronçons respectifs. Enfin, à l'opposé de son ouverture 35a, le troisième tronçon 35 est fermé par un fond 40, sur lequel est fixée (41) l'extrémité de la tige de piston 12.Note that the bottoms 3 and 8 of the first (1) and second (7) cylinders are extended by sails, which are fixed (3a, 8a) to the internal ends of the first (33) and second (34) sections of the boom telescopic and constitute the bottoms of these respective sections. Finally, opposite its opening 35a, the third section 35 is closed by a bottom 40, on which is fixed (41) the end of the piston rod 12.

La section S10 de la deuxième grande chambre 10 est, dans la réalisation décrite, égale à la section S6 de la première petite chambre 6. Du fait que ces deux chambres sont en communication permanente entre elles, et avec aucune autre chambre, le volume de fluide qui sort de l'une de ces deux chambres (ou qui y pénètre) est nécessairement reçu dans l'autre chambre (ou en sort). Lorsque les sections S10 et S6 sont égales, cela implique que le deuxième cylindre 7 se déplace par rapport au deuxième piston 9 à la même vitesse et simultanément au déplacement du premier cylindre 1 par rapport au premier piston 4. On obtient donc également les sorties ou les rentrées simultanées et à la même vitesse du premier tronçon 33 de la flèche par rapport au deuxième tronçon 34, et du deuxième tronçon 34 par rapport au troisième tronçon 35, ce qui est souhai­table pour l'application décrite aux flèches télescopiques de grue. Les courses relatives C33/34 et C34/35 du premier tronçon 33 par rapport au deuxième tronçon 34, et du deuxième tronçon 34 par rapport au troisième tronçon 35 sont en outre égales.The section S10 of the second large chamber 10 is, in the embodiment described, equal to the section S6 of the first small chamber 6. Because these two chambers are in permanent communication with one another, and with no other chamber, the volume of fluid which leaves one of these two chambers (or which enters it) is necessarily received in the other chamber (or leaves it). When sections S10 and S6 are equal, this implies that the second cylinder 7 moves with respect to the second piston 9 at the same speed and simultaneously with the movement of the first cylinder 1 with respect to the first piston 4. We therefore also obtain the simultaneous outputs or re-entries and at the same speed of the first section 33 of the boom relative to the second section 34, and the second section 34 relative to the third section 35, which is desirable for the application described for telescopic crane jibs. The relative strokes C33 / 34 and C34 / 35 of the first section 33 relative to the second section 34, and of the second section 34 relative to the third section 35 are also equal.

Mais on comprend bien qu'il suffit de modifier le rapport des sections S6/S10, pour, par exemple, si la section S6 était égale à la moitié de la section S10 [S6 =(S10) x 0,5], obtenir une vitesse de sortie, et une course, du premier tronçon 33 par rapport au deuxième tronçon 34, égales à deux fois la vitesse de sortie, et la course du deuxième tronçon 34 par rapport au troisième tronçon35.But we understand that it is enough to modify the ratio of the sections S6 / S10, for, for example, if the section S6 was equal to half of the section S10 [S6 = (S10) x 0.5], obtain a exit speed, and one stroke, of the first section 33 relative to the second section 34, equal to twice the exit speed, and the stroke of the second section 34 relative to the third section35.

Dans la réalisation représentée, la somme des volumes des première petite chambre 6 et deuxième grande chambre 10 a été supposée constante. En réalité, des fuites inévitables provoquent de légères variations de la valeur de cette somme des volumes, et il est souvent nécessaire de compléter la quantité de fluide con­tenu dans ces chambres, ou, au contraire, de permettre une évacua­tion de fluide excédentaire. Ce complément ou cette évacuation de fluide sont réalisés automatiquement de la manière suivante.In the embodiment shown, the sum of the volumes of the first small chamber 6 and the second large chamber 10 was assumed to be constant. In reality, inevitable leaks cause slight variations in the value of this sum of volumes, and it is often necessary to supplement the quantity of fluid contained in these chambers, or, on the contrary, to allow an evacuation of excess fluid. This complement or this evacuation of fluid is carried out automatically in the following manner.

Le distributeur à trois positions 24 est supposé avoir été placé dans sa première position.The three-position distributor 24 is assumed to have been placed in its first position.

Si la quantité du fluide contenu dans la deuxième grande chambre 10 devient insuffisante, la pression de ce fluide diminue et devient inférieure à la pression de tarage du manocontact 47, ce qui provoque la liaison électrique entre les deux bornes 48, 49 et, par conséquent, l'alimentation en énergie électrique du dispositif électromagnétique 45, qui place le distributeur de fluide à deux positions 44 dans sa deuxième position. Le fluide sous pression du conduit 28, véhiculé par les conduits 54, 55 et 42, parvient dans la deuxième grande chambre 10 jusqu'à compensation du fluide manquant. Lorsque la pression dans cette chambre redevient supé­rieure au tarage du manocontact 47, ce manocontact coupe l'alimen­tation en énergie électrique du dispositif électromagnétique 45 : le distributeur de fluide à deux positions 44 est replacé dans sa première position sous l'effet du ressort 46, ce qui provoque l'arrêt de l'arrivée complémentaire de fluide, par le conduit 42, dans la deuxième grande chambre 10.If the quantity of the fluid contained in the second large chamber 10 becomes insufficient, the pressure of this fluid decreases and becomes lower than the setting pressure of the pressure switch 47, which causes the electrical connection between the two terminals 48, 49 and, consequently , the supply of electrical energy to the electromagnetic device 45, which places the fluid distributor in two positions 44 in its second position. The pressurized fluid of the conduit 28, conveyed by the conduits 54, 55 and 42, arrives in the second large chamber 10 until compensation for the missing fluid. When the pressure in this chamber again becomes greater than the setting of the pressure switch 47, this pressure switch cuts off the supply of electrical energy to the electromagnetic device 45: the two-position fluid distributor 44 is returned to its first position under the effect of the spring 46, which causes the complementary supply of fluid to stop, via the conduit 42, in the second large chamber 10.

Si, au contraire, la quantité du fluide contenu dans la deuxième grande chambre tend à être excédentaire, la pression de ce fluide augmente jusqu'à atteindre la valeur de la pression de tarage du clapet de décharge 53 : au moyen de ce clapet de décharge 53, la pression maximale dans la deuxième grande chambre 10 est limitée à une valeur permettant d'interdire toute détérioration du vérin.If, on the contrary, the quantity of the fluid contained in the second large chamber tends to be in excess, the pressure of this fluid increases until reaching the value of the setting pressure of the relief valve 53: by means of this relief valve 53, the maximum pressure in the second large chamber 10 is limited to a value making it possible to prohibit any deterioration of the jack.

Il doit être observé que la différence des pressions de tarage du manocontact 47 et du clapet de décharge 53 permet d'éviter le fonctionnement permanent dudit clapet de décharge 53, et de limiter la quantité de fluide qui fait retour au réservoir 22 en traversant le clapet de décharge.It should be observed that the difference in the setting pressures of the pressure switch 47 and of the relief valve 53 makes it possible to avoid the permanent operation of said relief valve 53, and to limit the amount of fluid which returns to the reservoir 22 by passing through the valve. discharge.

La commande proprement dite du télescopage est la sui­vante:
    - pour la sortie des tronçons les uns par rapport aux autres, et l'extension de la flèche, on place le distributeur 24 dans sa première position : le fluide refoulé par la pompe 23 emplit la première grande chambre 5 ; le premier piston 4 se rapproche du fond 3 du premier cylindre 1 ; le fluide contenu dans la première petite chambre 6 est chassé hors de cette chambre et va emplir la deuxième grande chambre 10 ; le deuxième piston 9 se rapproche du fond 8 du deuxième cylindre 7 ; et le fluide contenu dans la deuxième petite chambre 11 en est chassé et, par les quatrième 19 et troisième conduits 18, et le conduit 29, retourne au réservoir 22 ;
    - pour la rentrée des divers tronçons et la rétraction de la flèche, la mise en place du distributeur 24 dans sa troisième position provoque les déplacements inverses de ceux décrits en ce qui concerne la sortie de ces tronçons.The actual telescoping control is as follows:
- For the output of the sections relative to each other, and the extension of the arrow, the distributor 24 is placed in its first position: the fluid discharged by the pump 23 fills the first large chamber 5; the first piston 4 approaches the bottom 3 of the first cylinder 1; the fluid contained in the first small chamber 6 is driven out of this chamber and will fill the second large chamber 10; the second piston 9 approaches the bottom 8 of the second cylinder 7; and the fluid contained in the second small chamber 11 is expelled therefrom and, through the fourth 19 and third conduits 18, and the conduit 29, returns to the reservoir 22;
- for the return of the various sections and the retraction of the boom, the installation of the distributor 24 in its third position causes the reverse displacements of those described with regard to the exit of these sections.

L'invention n'est pas limitée à la réalisation décrite, mais en couvre au contraire toutes les variantes qui pourraient lui être apportées sans sortir de son cadre, ni de son esprit.The invention is not limited to the embodiment described, but on the contrary covers all the variants which could be made to it without departing from its scope or its spirit.

Claims (7)

1. Vérin multiple à au moins trois éléments montés coulis­sants les uns par rapport aux autres, comprenant :
      - un premier cylindre (1) ;
      - un premier piston (4), qui est monté coulissant à l'intérieur du premier cylindre et qui délimite une première grande chambre (5), de grande section utile (S5), et une première petite chambre (6), de petite section utile (S6) ;
      - un deuxième cylindre (7), qui est solidaire du premier piston (4) et qui traverse un fond (3) du premier cylindre déli­mitant la première petite chambre (6) ;
      - un deuxième piston (9), qui est monté coulissant à l'intérieur du deuxième cylindre (7) et qui y délimite une deuxième grande chambre (10), de grande section utile (S10), et une deuxième petite chambre (11), de petite section utile (S11) ;
      - une tige de piston (12), qui est solidaire du deuxième piston (9) et qui traverse un fond (8) du deuxième cylindre (7) délimitant la deuxième petite chambre (11) ;
      - un premier passage (13), qui réalise la communication permanente entre la première petite chambre (6) et la deuxième grande chambre (10) ; et
      - deux raccords (20, 21) à deux conduits externes (28, 29) susceptibles (les conduits externes) d'être reliés, respecti­vement, à un dispositif (23) d'alimentation en fluide sous pression et à un échappement (22) de fluide sans pression, et inversement ; caractérisé en ce que les raccords (20, 21) sont disposés sur la tige de piston (12) ;
en ce que la première grande chambre (5) est reliée à un premier (20) des deux dits raccords par un deuxième passage, qui est lui-­même constitué par un premier conduit (14) qui est solidaire du premier piston (4), traverse (15) ce premier piston, débouche dans la première grande chambre (5) et est monté à coulissement télesco­pique étanche par rapport à un deuxième conduit (16), qui, lui, est solidaire du deuxième piston (9), traverse (17) ce deuxième piston, débouche dans la deuxième grande chambre (10) et est disposé à l'intérieur de la tige de piston (12) ; et en ce que la deuxième petite chambre (11) est reliée au deuxième (21) des deux dits raccords par un troisième passage, qui est lui-­même constitué par un troisième conduit (18), qui est ménagé dans la tige de piston (12), se prolonge (19) à l'intérieur du deuxième piston (9) et débouche dans la deuxième petite chambre (11).1. Multiple cylinder with at least three elements mounted to slide relative to one another, comprising:
- a first cylinder (1);
- a first piston (4), which is slidably mounted inside the first cylinder and which delimits a first large chamber (5), of large useful section (S5), and a first small chamber (6), of small section useful (S6);
- A second cylinder (7), which is integral with the first piston (4) and which passes through a bottom (3) of the first cylinder delimiting the first small chamber (6);
- a second piston (9), which is slidably mounted inside the second cylinder (7) and which delimits there a second large chamber (10), of large useful section (S10), and a second small chamber (11) , of small useful section (S11);
- a piston rod (12), which is integral with the second piston (9) and which passes through a bottom (8) of the second cylinder (7) delimiting the second small chamber (11);
- a first passage (13), which provides permanent communication between the first small chamber (6) and the second large chamber (10); and
- two connections (20, 21) to two external conduits (28, 29) capable (the external conduits) of being connected, respectively, to a device (23) for supplying pressurized fluid and to an exhaust (22) pressureless fluid, and vice versa; characterized in that the fittings (20, 21) are arranged on the piston rod (12);
in that the first large chamber (5) is connected to a first (20) of the two said connections by a second passage, which itself is constituted by a first conduit (14) which is integral with the first piston (4), crosspiece (15) this first piston, opens into the first large chamber (5) and is mounted in sealed telescopic sliding relative to a second conduit (16), which is itself integral with the second piston (9), crosspiece (17 ) this second piston, opens into the second large chamber (10) and is arranged inside the piston rod (12); and in that the second small chamber (11) is connected to the second (21) of the two said connections by a third passage, which itself is constituted by a third conduit (18), which is formed in the piston rod ( 12), extends (19) inside the second piston (9) and opens into the second small chamber (11). 2. Vérin multiple selon la revendication 1, caractérisé en ce qu'il comporte un cinquième conduit (42), qui est contenu dans la tige de piston (12), qui débouche dans la deuxième grande chambre (10) et qui est raccordé à un dispositif sélectif de complément d'alimentation en fluide sous pression (44, 47).2. Multiple cylinder according to claim 1, characterized in that it comprises a fifth conduit (42), which is contained in the piston rod (12), which opens into the second large chamber (10) and which is connected to a selective device for supplementing the supply of pressurized fluid (44, 47). 3. Vérin multiple selon la revendication 2, caractérisé en ce que le dispositif sélectif de complément d'alimentation en fluide sous pression est constitué par :
      - un distributeur de fluide à deux positions (44) ;
      - un conduit de liaison (54), qui relie ce distributeur de fluide à deux positions (44) audit raccord (20), auquel est relié le deuxième conduit (16) ; et
      - un conduit de complément d'alimentation (55), qui relie ledit distributeur de fluide à deux positions (44) audit cinquième conduit (42) ;
      les deux positions du distributeur de fluide à deux posi­tions correspondant, la première position, à l'obturation du conduit de complément d'alimentation (55), et, la deuxième posi­tion, à la mise en communication du conduit de liaison (54) avec le conduit de complément d'alimentation (55).3. Multiple cylinder according to claim 2, characterized in that the selective device for supplementing the supply of pressurized fluid consists of:
- a two-position fluid distributor (44);
- a connecting duct (54), which connects this two-position fluid distributor (44) to said fitting (20), to which the second duct (16) is connected; and
- a supply complement duct (55), which connects said two-position fluid distributor (44) to said fifth duct (42);
the two positions of the two-position fluid distributor corresponding, the first position, to shutting off the additional supply duct (55), and, the second position, to placing the connecting duct (54) in communication with the feed complement duct (55). 4. Vérin multiple selon la revendication 3, caractérisé en ce que le distributeur de fluide à deux positions (44) comporte un dispositif électromagnétique de réglage de sa position (45) qui est relié (58) à l'une (48) des bornes électriques (48, 49) d'un mano­contact (47), qui est lui-même relié (57) audit conduit de complé­ment d'alimentation (55).4. Multiple cylinder according to claim 3, characterized in that the two-position fluid distributor (44) comprises an electromagnetic device for adjusting its position (45) which is connected (58) to one (48) of the terminals electrical (48, 49) of a pressure switch (47), which is itself connected (57) to said supply complement duct (55). 5. Vérin multiple selon l'une quelconque des revendications 2 à 4, caractérisé en ce qu'il comporte un clapet de décharge taré (53) relié en dérivation (56, 55) audit cinquième conduit (42).5. Multiple cylinder according to any one of claims 2 to 4, characterized in that it comprises a calibrated relief valve (53) connected in bypass (56, 55) to said fifth conduit (42). 6. Flèche télescopique comportant un premier tronçon (33), interne, un deuxième tronçon (34), intermédiaire, à l'intérieur duquel le premier tronçon (33) est monté coulissant, et un troi­sième tronçon (35), externe, à l'intérieur duquel le deuxième tronçon (34) est monté coulissant,
caractérisée en ce qu'un vérin selon l'une quelconque des revendi­cations 1 à 5 y est monté, longitudinalement (32) à l'intérieur des trois dits tronçons, le premier cylindre (1) étant solidaire (3a) du premier tronçon (33), le deuxième cylindre (7) étant solidaire (8a) du deuxième tronçon (34) et la tige de piston (12) étant soli­daire (41-40) du troisième tronçon (35).6. Telescopic boom comprising a first section (33), internal, a second section (34), intermediate, inside which the first section (33) is slidably mounted, and a third section (35), external, to the '' inside which the second section (34) is slidably mounted,
characterized in that a cylinder according to any one of claims 1 to 5 is mounted therein, longitudinally (32) inside the three said sections, the first cylinder (1) being integral (3a) with the first section (33 ), the second cylinder (7) being integral (8a) with the second section (34) and the piston rod (12) being integral (41-40) with the third section (35). 7. Flèche selon la revendication 6, caractérisée en ce que le premier cylindre (1) est fixé (3a) sur l'extrémité interne du premier tronçon (33), le deuxième cylindre (7) est fixé (8a) sur l'extrémité interne du deuxième tronçon (34) et la tige de piston (12) est fixée (41) sur la partie (40) du troisième tronçon (35), qui est opposée à l'ouverture axiale (35a) de ce troisième tronçon par laquelle pénètre le deuxième tronçon (34).7. Boom according to claim 6, characterized in that the first cylinder (1) is fixed (3a) on the internal end of the first section (33), the second cylinder (7) is fixed (8a) on the end internal of the second section (34) and the piston rod (12) is fixed (41) to the part (40) of the third section (35), which is opposite to the axial opening (35a) of this third section through which enters the second section (34).
EP19880401457 1987-06-15 1988-06-14 Multi-stage actuator with at least three sliding elements and telescopic jib incorporating this actuator Expired - Lifetime EP0296047B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8708297 1987-06-15
FR8708297A FR2616489A1 (en) 1987-06-15 1987-06-15 MULTIPLE CYLINDER WITH AT LEAST THREE SLIDING ELEMENTS AND TELESCOPIC ARROW BY APPLYING

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EP0296047A1 true EP0296047A1 (en) 1988-12-21
EP0296047B1 EP0296047B1 (en) 1991-04-03

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DE (1) DE3862246D1 (en)
FR (1) FR2616489A1 (en)

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Cited By (16)

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EP0446115A1 (en) * 1990-03-06 1991-09-11 Ppm Societe Anonyme: Multiple actuator, supply circuit for such an actuator and telescopic boom as an application of this actuator
FR2659398A1 (en) * 1990-03-06 1991-09-13 Ppm Sa MULTIPLE CYLINDER, POWER SUPPLY CIRCUIT OF SUCH A VERIN, AND TELESCOPIC ARROW USING THIS CYLINDER.
US5111733A (en) * 1990-03-06 1992-05-12 Ppm Multiple stage hydraulic jack for use with telescopic jib
EP0551716A1 (en) * 1992-01-14 1993-07-21 SIMON CELLA S.r.L. An hydraulic piston and cylinder unit
US5435228A (en) * 1993-07-20 1995-07-25 Pneumatic Energy Inc Pneumatic transformer
EP0849824A1 (en) * 1996-12-20 1998-06-24 Yuasa Koki Co Ltd Device for raising and lowering apparatus
US5850713A (en) * 1996-12-20 1998-12-22 Yuasa Koki Co., Ltd Device raising and lowering apparatus
KR100597531B1 (en) * 1998-04-06 2006-07-10 그로우브 유.에스. 엘.엘.씨. Telescoping system with multi-stage telescopic cylinder
CN102678662A (en) * 2012-05-14 2012-09-19 长沙金阳机械设备科技开发有限公司 Fast-slow speed stoke integrated energy-saving oil cylinder and application device thereof
FR3013744A1 (en) * 2013-11-26 2015-05-29 Greffet Sas A HYDRAULIC TAPPING SYSTEM CHARACTERIZED BY A 2000-MM LINEAR TELESCOPIC ARM ADJUSTABLE IN ROTATION AT MORE OR LESS 45 ° OF THE ROAD
ITUB20160363A1 (en) * 2016-01-29 2017-07-29 Manitou Italia Srl Telescopic arm for self-propelled operating machines.
EP3199485A3 (en) * 2016-01-29 2017-08-09 Manitou Italia S.r.l. A telescopic arm for self-propelled operating machines
US10017363B2 (en) 2016-01-29 2018-07-10 Manitou Italia S.R.L. Telescopic arm for self-propelled operating machines
AU2016269490B2 (en) * 2016-01-29 2022-07-07 Manitou Italia S.R.L. A telescopic arm for self-propelled operating machines
CN105782160A (en) * 2016-05-11 2016-07-20 中国工程物理研究院总体工程研究所 Single-rod inlet and outlet bi-direction equal-load hydraulic cylinder
CN110296262A (en) * 2019-06-27 2019-10-01 佛山市恒力泰机械有限公司 A kind of multiple drive power cylinder and a kind of inserted valve of multiple drive power

Also Published As

Publication number Publication date
EP0296047B1 (en) 1991-04-03
DE3862246D1 (en) 1991-05-08
FR2616489A1 (en) 1988-12-16

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