EP0425567B1 - Pipe shunt for a two-cylinder pump for viscous fluids - Google Patents

Pipe shunt for a two-cylinder pump for viscous fluids Download PDF

Info

Publication number
EP0425567B1
EP0425567B1 EP89908693A EP89908693A EP0425567B1 EP 0425567 B1 EP0425567 B1 EP 0425567B1 EP 89908693 A EP89908693 A EP 89908693A EP 89908693 A EP89908693 A EP 89908693A EP 0425567 B1 EP0425567 B1 EP 0425567B1
Authority
EP
European Patent Office
Prior art keywords
ring
pipe
axial
rubber
pivot
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
EP89908693A
Other languages
German (de)
French (fr)
Other versions
EP0425567A1 (en
Inventor
Karl Schlecht
Hartmut Benckert
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.)
Putzmeister Concrete Pumps GmbH
Original Assignee
Putzmeister Werk Maschinenfabrik GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Putzmeister Werk Maschinenfabrik GmbH filed Critical Putzmeister Werk Maschinenfabrik GmbH
Publication of EP0425567A1 publication Critical patent/EP0425567A1/en
Application granted granted Critical
Publication of EP0425567B1 publication Critical patent/EP0425567B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B17/00—Pumps characterised by combination with, or adaptation to, specific driving engines or motors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B7/00—Piston machines or pumps characterised by having positively-driven valving
    • F04B7/0084—Component parts or details specially adapted therefor
    • F04B7/0088—Sealing arrangements between the distribution members and the housing
    • F04B7/0096—Sealing arrangements between the distribution members and the housing for pipe-type distribution members

Definitions

  • the invention relates to a pipe switch of a two-cylinder thick matter pump with a swivel tube pivotable in front of a cylinder-side spectacle plate, with an axially displaceably arranged on the spectacle-side end of the swivel tube, which can be pressed against the spectacle plate by means of the hydrostatic internal pressure in the swivel tube and with a wear ring between the swivel tube and the A rubber-elastic ring arranged on the wear ring, the wear ring having at its end on the swivel tube side an axial guide surface guided on a radially outward-pointing cylindrical centering surface of the swivel tube, together with the centering surface delimiting a sealing gap, and on its spectacle-side end an annular shoulder pointing radially inward from the axial guide surface, whose front outer surface rests against the eyeglass plate and its inner surface serving the rubber-elastic ring as an axial abutment by an axial through which elastic ring bridged.,
  • the space is separated from the end face of the swivel tube and the swivel tube has at its front end a recess which preferably has the shape of a rectangular step and is open towards the axial guide surface and engages under the sealing ring on the inside.
  • Pipe switches of this type which referred to an automatic hydrostatic adjustment, called an automatic ring Wear wear ring are known (DE-C-26 14 895 and DE-A-31 03 321).
  • DE-C-26 14 895 and DE-A-31 03 321 in order to accommodate the rubber-elastic ring, mutually facing ring rotations, which engage under the ends of the rubber-elastic ring, are provided both in the swivel tube and in the wear ring.
  • Abrasive material can penetrate into the area of the ring twists and migrate behind the rubber-elastic ring.
  • this material can reach the radial gap between the wear ring and the swivel tube and exit through the radial gap, while the material penetrating the backward rotation between the wear ring and the sealing ring can no longer escape to the inside of the tube when the pressure is released.
  • the latter leads to an axial bracing of the pipe switch and thus to a heavy, wear-promoting switching.
  • the backward rotation is gradually filled with the hardening material, so that the elastic sealing ring can be drawn towards the inside of the pipe with increasing wear and increasing axial air and can be lost in the process. This is particularly the case if the thick matter pump draws vacuum during the backward conveyance.
  • the axial relative movement between the swivel tube and the wear tube can also lead to premature wear there under the action of the hardening material that escapes to the outside.
  • the axial movement mentioned is between, depending on the elasticity of the surrounding pump housing 1 and 3 mm.
  • the object of the invention is to create a pipe switch for two-cylinder thick matter pumps of the type specified at the outset, which ensures a reliable seal against material leakage and a low-wear axial guidance between the wear ring and the pipe switch.
  • the wear ring In practical operation, it is particularly important that when switching the pipe switch and clamping solid particles such as stones and the like between the wear ring and the glasses, the wear ring can spring back somewhat both in the axial and in the radial direction and can also tilt slightly. Furthermore, care must be taken to ensure that the abrasive material does not reach the sealing gap as far as possible and is deposited in the area of the sealing ring and can grow there gradually after hardening.
  • the inner surface of the ring shoulder formed on the wear ring is designed to be stepless in its region serving the rubber-elastic ring as an axial abutment towards the pipe interior and that the turning in the swivel pipe over at least the rubber-elastic ring engages under one third, preferably over more than half or even two thirds of its axial extent.
  • the rubber-elastic ring rests with its radial outer surface while performing an axial guide function, against the part of the axial guide surface of the wear ring bridging the recess and with its front end face against the axial inner surface of the ring shoulder arranged on the wear ring.
  • the rubber-elastic ring is supported with its radial inner surface by bridging the front space between the swivel tube and the ring shoulder against the radial boundary surface of the recess and with its rear end surface against the axial boundary surface of the recess of the swivel tube.
  • the arrangement according to the invention When pressurized, the arrangement according to the invention has the effect that the material to be conveyed, which tends to harden from the inside of the tube and pressures under elastic deformation, presses into the rubber-elastic ring in the region of its end face on the spectacle side.
  • the elastic ring in its rear part is pressed firmly against the sealing gap in the area of the axial guide surface between the wear ring and the swivel tube.
  • the tube switch can spring back in the direction of the spectacle plate due to the elastic deformation of the elastic ring.
  • radially continuous axially open grooves can also be arranged on the end face of the swivel tube, which grooves only have to be about 1 to 2 mm deep.
  • Another possibility of resilience in the sense described above and the access of material to be conveyed for the purpose of hydrastatic loading can be achieved in that bevels or preferably wedge-shaped ring grooves are arranged on the elastic ring towards the inside of the pipe. If the chamfers or ring grooves are provided at both ends, the sealing ring can be inserted regardless of the direction and turned over in the event of wear, thus doubling its service life. The chamfer on both sides also increases the resilience volume.
  • the swivel tube can be provided with a step stop for the wear ring at the rear end of the cylindrical axial guide surface, which ensures that the The gap remains open even when the wear ring is struck.
  • the part of the axial guide surface of the wear ring opposite the pivot tube or in the part of the wear ring can be used opposite part of the axial guide surface of the swivel tube, an annular groove for receiving an O-ring can be left out.
  • the diameter of the axial guide surface of the wear ring is larger than the effective diameter or even larger than the front outer diameter of the ring shoulder with which the wear ring rests on the spectacle plate. It is particularly advantageous if the ring surfaces of the wear ring acted upon by the hydrostatic pressure are designed such that the effective diameter of the force acting between the tube switch and the wear ring in the pressing direction is greater than the effective diameter of the force acting between the spectacle plate and the wear ring in the lifting direction Force.
  • the pipe switch shown in the drawing is intended for a two-cylinder thick matter pump, the delivery cylinders, not shown, of which are covered by a replaceable spectacle plate 5 on their mouths on the side of a material feed container.
  • a swivel tube 2 is arranged with its end face in front of the spectacle plate 5 so that it can swivel back and forth about a horizontal axis in such a way that its opening 20 alternately reaches one or the other of the two openings 4 of the spectacle plate 5 and the other opening 4 releases to the material feed container.
  • the swivel tube 2 opens into a delivery line, not shown.
  • a wear ring 1 With its cylindrical axial guide surface 21 is axially displaceably mounted on the cylindrical guide and centering surface 7 of the shoe tube 2.
  • the wear ring 1 At its front end, the wear ring 1 has a radially inwardly facing ring shoulder 22, the outer end face 23 of which against the surface 24 of the spectacle plate 5 rests and the annular inner surface 17 of which lies opposite the end face 16 of the swivel tube 2.
  • the ring 3 lies with its radial inner surface against the radial boundary surface 8 and with its rear end face 12 'against the axial step 6 of the turn in the pipe switch 2, while it with its radial outer surface against the part of the axial guide surface 21 of the wear ring bridging the turn 1 and rests with its front end face 12 against the radially outer part of the inner ring face 17 of the wear ring 1.
  • the end face 16 of the swivel tube 2 is separated from the inner surface 17 of the wear ring 1 by radially continuous, axially open grooves 11 or an annular gap 18, so that the viscous conveyed material conveyed under pressure by the swivel tube 2 directly from the inside to the grooves 11 or can reach the gap 18 bridging part of the elastic ring 3.
  • the swivel tube 2 strikes with the upper edge of the grooves 11 in the region of the inner surface 17 against the wear ring 1, while in the case of FIGS. 2 and 3 a step 15 is provided in the rear region of the swivel tube 2 as a limit stop for the wear ring 1.
  • the rubber-elastic ring 3 with its essentially rectangular cross-section takes on not only a sealing function due to its var tension but also the function of automatic tracking of the wear ring 1 in the event of wear.
  • its radial outer surface represents an extension of the axial guide and centering surface 21.
  • the axial extent of the ring 3 is at least twice, preferably one Multiple of the axial extent of the guide and centering surface 21 on the swivel tube 2, there is the possibility within the necessary play between the wear ring 1 and the swivel tube 2 in the area of the centering surface 21 that the wear ring 1 due to the elastic properties of the ring 3 can tilt easily if solid particles get into the gap area between the contact surfaces 23 and 24 of the wear ring 1 and the spectacle plate 5. This results in a considerable reduction in wear and thus a longer service life of the wear ring 1 and the spectacle plate 5.
  • the ring surfaces 23 and 17 of the wear ring 1, which are acted upon by the hydrostatic pressure, are arranged and designed such that the force 31 acting in the pressing direction is greater than the lifting force 30.
  • the effective diameter 10 of the force 31 acting between the swivel tube 2 and the wear ring 1 in the pressing direction is greater than the effective diameter 9 of the force 30 acting between the spectacle plate 5 and the wear ring 1 in the lifting direction.
  • the axial guide - And centering diameter 7 of the wear ring 1 larger than the effective diameter 9, with which the wear ring 1 rests on the eyeglass plate 5 and even larger than the end outer diameter of the ring shoulder 22, with which the wear ring 1 rests on the eyeglass plate 5.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Joints Allowing Movement (AREA)
  • Reciprocating Pumps (AREA)
  • Sealing Devices (AREA)

Abstract

A pipe shunt for a two-cylinder pump for viscous fluids contains a swivelling pipe (2) with a turned groove (6, 8) in the form of a right-angled step at its front end which receives an elastic rubber ring (3). The radial outer surface of said ring rests against the part of the turned groove (6, 8) which bridges the axial guiding surface (21) of an abrasion ring (1) and the front face (12) of said ring rests against the axial inner surface (17) of a ring shoulder (22) arranged on the abrasion ring (1). The radial inner surface of the elastic rubber ring (3) bridges a gap between the abrasion ring (1) and the swivelling pipe (2) and rests against the radial limiting surface (8), and the rear surface (12') of the elastic rubber ring (3) rests against the axial limiting surface (6) of the turned groove in the swivelling pipe (2). The abrasion ring (1), which is axially mobile on the swivelling pipe (2) and can be adjusted by means of the elastically pretensioned ring (2), is thrust by means of the hydrostatic internal pressure in the swivelling pipe (2) against a bridge plate (5), before the swivelling pipe (2) can be swivelled so that orifices (4) communicating with the delivery cylinders of the pump for viscous fluids communicate alternately with the swivelling pipe (2) and with a fluid dispenser.

Description

Die Erfindung betrifft eine Rohrweiche einer Zweizylinder-Dickstoffpumpe mit einem vor einer zylinderseitigen Brillenplatte verschwenkbaren Schwenkrohr, mit einem auf dem brillenseitigen Ende des Schwenkrohrs axial verschiebbar angeordneten, mit Hilfe des hydrostatischen Innendrucks im Schwenkrohr gegen die Brillenplatte anpreßbaren Verschleißring und mit einem zwischen dem Schwenkrohr und dem Verschleißring angeordneten gummielastischen Ring, wobei der Verschleißring an seinem schwenkrohrseitigen Ende eine auf einer radial nach außen weisenden zylindrischen Zentrierfläche des Schwenkrohrs geführte, zusammen mit der Zentrierfläche einen Dichtspalt begrenzende Axialführungsfläche und an seinem brillenseitigen Ende einen von der Axialführungsfläche aus radial nach innen weisenden Ringansatz aufweist, dessen stirnseitige Außenfläche gegen die Brillenplatte anliegt und dessen dem gummielastischen Ring als axiales Widerlager dienende Innenfläche durch einen axialen, durch den gummielastischen Ring überbrückter., zum Rohrinneren hin offenen. Zwischenraum von der Stirnfläche des Schwenkrohrs getrennt ist und wobei das Schwenkrohr an seinem stirnseitigen Ende eine vorzugsweise die Gestalt einer Rechteckstufe aufweisende, zur Axialführungsfläche hin offene, den Dichtring innenseitig untergreifende Eindrehung aufweist.The invention relates to a pipe switch of a two-cylinder thick matter pump with a swivel tube pivotable in front of a cylinder-side spectacle plate, with an axially displaceably arranged on the spectacle-side end of the swivel tube, which can be pressed against the spectacle plate by means of the hydrostatic internal pressure in the swivel tube and with a wear ring between the swivel tube and the A rubber-elastic ring arranged on the wear ring, the wear ring having at its end on the swivel tube side an axial guide surface guided on a radially outward-pointing cylindrical centering surface of the swivel tube, together with the centering surface delimiting a sealing gap, and on its spectacle-side end an annular shoulder pointing radially inward from the axial guide surface, whose front outer surface rests against the eyeglass plate and its inner surface serving the rubber-elastic ring as an axial abutment by an axial through which elastic ring bridged., open to the inside of the pipe. The space is separated from the end face of the swivel tube and the swivel tube has at its front end a recess which preferably has the shape of a rectangular step and is open towards the axial guide surface and engages under the sealing ring on the inside.

Rohrweichen dieser Art, die einen selbsttätig hydrostatisch nachstellenden, als Automatikring bezeichneten Verschleißring tragen, sind bekannt (DE-C-26 14 895 und DE-A-31 03 321). Zur Aufnahme des gummielastischen Rings sind im Falle der DE-A-31 03 321 einander zugewandte, die Enden des gummielastischen Rings untergreifende Ringeindrehungen sowohl im Schwenkrohr als auch im Verschleißring vorgesehen. In den Bereich der Ringeindrehungen kann abrassives Material eindringen und den gummielastischen Ring hinterwandern. Auf der Seite des Schwenkrohrs kann dieses Material zum Radialspalt zwischen Verschleißring und Schwenkrohr gelangen und durch den Radialspalt hindurch nach außen austreten, während das in die Hinterdrehung zwischen Verschleißring und Dichtring eindringende Material bei der Druckentlastung nicht mehr nach dem Rohrinneren entweichen kann. Letzteres führt zu einer axialen Verspannung der Rohrweiche und damit zu einem schweren, verschleißfördernden Durchschalten. Hinzu kommt, daß die Hinterdrehung allmählich mit dem erhärtenden Material ausgefüllt wird, so daß der elastische Dichtring bei zunehmendem Verschleiß und zunehmender Axialluft nach dem Rohrinneren gezogen werden und dabei verloren gehen kann. Dies ist besonders dann der Fall, wenn die Dickstoffpumpe bei der Rückwärtsförderung Vakuum zieht. Auch die axiale Relativbewegung zwischen dem Schwenkrohr und dem Verschleißrohr, wie sie vor allem bei der Förderung unter Hochdruck auftritt, kann dort unter der Einwirkung des nach außen dringenden erhärtenden Materials zu einem frühzeitigen Verschleiß führen. Die genannte Axialbewegung beträgt bei dem zyklischen Druckanstieg je nach Elastizität des umgebenden Pumpengehäuses zwischen 1 und 3 mm.Pipe switches of this type, which referred to an automatic hydrostatic adjustment, called an automatic ring Wear wear ring are known (DE-C-26 14 895 and DE-A-31 03 321). In the case of DE-A-31 03 321, in order to accommodate the rubber-elastic ring, mutually facing ring rotations, which engage under the ends of the rubber-elastic ring, are provided both in the swivel tube and in the wear ring. Abrasive material can penetrate into the area of the ring twists and migrate behind the rubber-elastic ring. On the side of the swivel tube, this material can reach the radial gap between the wear ring and the swivel tube and exit through the radial gap, while the material penetrating the backward rotation between the wear ring and the sealing ring can no longer escape to the inside of the tube when the pressure is released. The latter leads to an axial bracing of the pipe switch and thus to a heavy, wear-promoting switching. In addition, the backward rotation is gradually filled with the hardening material, so that the elastic sealing ring can be drawn towards the inside of the pipe with increasing wear and increasing axial air and can be lost in the process. This is particularly the case if the thick matter pump draws vacuum during the backward conveyance. The axial relative movement between the swivel tube and the wear tube, as occurs especially when conveying under high pressure, can also lead to premature wear there under the action of the hardening material that escapes to the outside. Given the cyclical pressure increase, the axial movement mentioned is between, depending on the elasticity of the surrounding pump housing 1 and 3 mm.

Ausgehend hiervon liegt der Erfindung die Aufgabe zugrunde, eine Rohrweiche für Zweizylinder-Dickstoffpumpen der eingangs angegebenen Art zu schaffen, die eine zuverlässige Abdichtung gegen Materialaustritt und eine verschleißarme Axialführung zwischen Verschleißring und Rohrweiche gewährleistet.Proceeding from this, the object of the invention is to create a pipe switch for two-cylinder thick matter pumps of the type specified at the outset, which ensures a reliable seal against material leakage and a low-wear axial guidance between the wear ring and the pipe switch.

Zur Lösung dieser Aufgabe werden die im Patentanspruch 1 angegebenen Merkmale vorgeschlagen. Vorteilhafte Ausgestaltungen und Weiterbildungen des Erfindungsgedankens ergeben sich aus den abhängigen Ansprüchen.To achieve this object, the features specified in claim 1 are proposed. Advantageous refinements and developments of the inventive concept result from the dependent claims.

Im praktischen Betrieb ist es besonders wichtig, daß beim Durchschalten der Rohrweiche und Einklemmen von Feststoffteilchen, wie Steine und dergleichen, zwischen dem Verschleißring und der Brille der Verschleißring sowohl in axialer als auch in radialer Richtung etwas nachfedern und dazuhin leicht ankippen kann. Weiter muß dafür gesorgt werden, daß das abrassive Material möglichst nicht zum Dichtspalt gelangen und sich im Bereich des Dichtringes ablagern und dort nach dem Aushärten allmählich aufwachsen kann. Um dies zu erreichen, wird gemäß der Erfindung vorgeschlagen, daß die Innenfläche des am Verschleißring angeformten Ringansatzes in seinem dem gummielastischen Ring als axiales Widerlager dienenden Bereich zum Rohrinneren hin stufenfrei ausgebildet ist und daß die Eindrehung im Schwenkrohr den gummmielastischen Ring über mindestens ein Drittel, vorzugsweise über mehr als die Hälfte oder gar zwei Drittel seiner axialen Ausdehnung untergreift. Der gummielastische Ring liegt dabei mit seiner radialen Außenfläche unter Ausübung einer Axialführungsfunktion, gegen den die Eindrehung überbrückenden Teil der Axialführungsfläche des Verschleißrings und mit seiner vorderen Stirnfläche gegen die axiale Innenfläche des am Verschleißring angeordneten Ringansatzes an. Weiter stützt sich der gummielastische Ring mit seiner radialen Innenfläche unter Überbrückung des stirnseitigen Zwischenraums zwischen Schwenkrohr und Ringansatz gegen die radiale Begrenzungsfläche der Eindrehung und mit seiner rückwärtigen Stirnfläche gegen die axiale Begrenzungsfläche der Eindrehung des Schwenkrohres ab.In practical operation, it is particularly important that when switching the pipe switch and clamping solid particles such as stones and the like between the wear ring and the glasses, the wear ring can spring back somewhat both in the axial and in the radial direction and can also tilt slightly. Furthermore, care must be taken to ensure that the abrasive material does not reach the sealing gap as far as possible and is deposited in the area of the sealing ring and can grow there gradually after hardening. In order to achieve this, it is proposed according to the invention that the inner surface of the ring shoulder formed on the wear ring is designed to be stepless in its region serving the rubber-elastic ring as an axial abutment towards the pipe interior and that the turning in the swivel pipe over at least the rubber-elastic ring engages under one third, preferably over more than half or even two thirds of its axial extent. The rubber-elastic ring rests with its radial outer surface while performing an axial guide function, against the part of the axial guide surface of the wear ring bridging the recess and with its front end face against the axial inner surface of the ring shoulder arranged on the wear ring. Furthermore, the rubber-elastic ring is supported with its radial inner surface by bridging the front space between the swivel tube and the ring shoulder against the radial boundary surface of the recess and with its rear end surface against the axial boundary surface of the recess of the swivel tube.

Bei Druckbeaufschlagung bewirkt die erfindungsgemäße Anordnung, daß das vom Rohrinneren in den Zwischenraum gelangende, zur Erhärtung neigende Fördergut unter druckelastischer Verformung in den gummielastischen Ring im Bereich seiner brillenseitigen Stirnseite eindrückt. Dadurch wird der elastische Ring in seinem rückwärtigen Teil fest gegen den Dichtspalt im Bereich der axialen Führungsfläche zwischen Verschleißring und Schwenkrohr angedrückt. Auch wenn das Material erhärtet, kann dabei die Rohrweiche bei Druckentlastung durch die elastische Verformung des elastischen Ringes wieder in Richtung zur Brillenplatte zurückfedern. Um die Verformungsmöglichkeit des elastischen Ringes zu gewährleisten, verbleibt zwischen der Stirnseite des Schwenkrohrs und der dieser zugewandten Innenfläche des Ringansatzes am Verschleißring ein Spalt. Um den Fördergutzutritt zum hydrostatisch dichtenden elastischen Ring zu verbessern, können an der Stirnseite des Schwenkrohrs darüber hinaus radial durchgehende axial offene Nuten angeordnet werden, die nur etwa 1 bis 2 mm tief sein müssen. Eine weitere Möglichkeit der Nachfederung im vorbeschriebenen Sinne und des Zutritts von Fördergut zum Zwecke der hydrastatischen Belastung kann dadurch erzielt werden, daß an dem elastischen Ring nach dem Rohrinneren weisende Fasen oder vorzugsweise keilförmige Ringnuten angeordnet werden. Wenn die Fasen oder Ringnuten an beiden Enden vorgesehen sind, kann der Dichtring richtungsunabhängig eingelegt und im Verschleißfalle gewendet und damit seine Lebensdauer verdoppelt werden. Die beidseitige Anfasung führt außerdem zu einer Vergrößerung des Nachfederungsvolumens.When pressurized, the arrangement according to the invention has the effect that the material to be conveyed, which tends to harden from the inside of the tube and pressures under elastic deformation, presses into the rubber-elastic ring in the region of its end face on the spectacle side. As a result, the elastic ring in its rear part is pressed firmly against the sealing gap in the area of the axial guide surface between the wear ring and the swivel tube. Even if the material hardens, the tube switch can spring back in the direction of the spectacle plate due to the elastic deformation of the elastic ring. In order to ensure the possibility of deformation of the elastic ring, there remains between the end face of the swivel tube and the inner surface thereof facing it Ring approach on the wear ring a gap. In order to improve the access to the conveyed material to the hydrostatically sealing elastic ring, radially continuous axially open grooves can also be arranged on the end face of the swivel tube, which grooves only have to be about 1 to 2 mm deep. Another possibility of resilience in the sense described above and the access of material to be conveyed for the purpose of hydrastatic loading can be achieved in that bevels or preferably wedge-shaped ring grooves are arranged on the elastic ring towards the inside of the pipe. If the chamfers or ring grooves are provided at both ends, the sealing ring can be inserted regardless of the direction and turned over in the event of wear, thus doubling its service life. The chamfer on both sides also increases the resilience volume.

Um bei etwas größerem Spalt zwischen dem Verschleißring und dem Schwenkrohr ein zu starkes Verpressen des elastischen Rings beim mechanischen Nachstellen der Rohrweiche zu verhindern, kann das Schwenkrohr am rückwärtigen Ende der zylindrischen Axialführungsfläche mit einem Stufenanschlag für den Verschleißring versehen werden, der dafür sorgt, daß der Spalt auch bei angeschlagenem Verschleißring offen bleibt.In order to prevent the elastic ring from being pressed too hard during mechanical adjustment of the pipe switch in the event of a slightly larger gap between the wear ring and the swivel tube, the swivel tube can be provided with a step stop for the wear ring at the rear end of the cylindrical axial guide surface, which ensures that the The gap remains open even when the wear ring is struck.

Um bei bestimmten Fördergütern eine sichere Axialabdichtung zu erreichen oder diese zu verbessern, kann in dem dem Schwenkrohr gegenüberliegenden Teil der Axialführungsfläche des Verschleißrings oder in dem dem Verschleißring gegenüberliegenden Teil der Axialführungsfläche des Schwenkrohrs eine Ringnut zur Aufnahme eines O-Ringes ausgespart werden.In order to achieve or improve a secure axial seal for certain conveyed goods, the part of the axial guide surface of the wear ring opposite the pivot tube or in the part of the wear ring can be used opposite part of the axial guide surface of the swivel tube, an annular groove for receiving an O-ring can be left out.

Vorteilhafterweise ist der Durchmesser der axialen Führungsfläche des Verschleißringes größer als der Wirkdurchmesser oder sogar größer als der stirnseitige Außendurchmesser des Ringansatzes, mit welchem der Verschleißring an der Brillenplatte anliegt. Besonders vorteilhaft ist es, wenn die mit dem hydrostatischen Druck beaufschlagten Ringflächen des Verschleißrings so ausgebildet sind, daß der Wirkdurchmesser der zwischen der Rohrweiche und dem Verschleißring in anpressender Richtung wirkenden Kraft größer ist als der Wirkdurchmesser der zwischen der Brillenplatte und dem Verschleißring in abhebender Richtung wirkenden Kraft.Advantageously, the diameter of the axial guide surface of the wear ring is larger than the effective diameter or even larger than the front outer diameter of the ring shoulder with which the wear ring rests on the spectacle plate. It is particularly advantageous if the ring surfaces of the wear ring acted upon by the hydrostatic pressure are designed such that the effective diameter of the force acting between the tube switch and the wear ring in the pressing direction is greater than the effective diameter of the force acting between the spectacle plate and the wear ring in the lifting direction Force.

Im folgenden wird die Erfindung anhand einiger in der Zeichnung in schematischer Weise dargestellter Ausführungsbeispiele näher erläutert. Es zeigen

  • Fig. 1a einen Längsschnitt durch das zylinderseitige Ende einer Rohrweiche einer Zweizylinder-Dickstoffpumpe;
  • Fig. 1b eine Darstellung der unter der Einwirkung des hydrostatischen Drucks auf den Verschleißring wirkenden Kräfte beim Ausführungsbeispiel nach Fig. 1a;
  • Fig. 2 ein abgewandeltes Ausführungsbeispiel einer Rohrweiche in einer der Fig. 1a entsprechenden Darstellung;
  • Fig. 3 ein weiteres abgewandeltes Ausführungsbeispiel der Rohrweiche in einer der Fig. 2 entsprechenden Darstellung.
In the following, the invention will be explained in more detail with reference to some exemplary embodiments shown schematically in the drawing. Show it
  • 1a shows a longitudinal section through the cylinder-side end of a pipe switch of a two-cylinder thick matter pump;
  • 1b shows the forces acting on the wear ring under the action of the hydrostatic pressure in the exemplary embodiment according to FIG. 1a;
  • FIG. 2 shows a modified exemplary embodiment of a pipe switch in a representation corresponding to FIG. 1a;
  • Fig. 3 shows another modified embodiment of the pipe switch in a representation corresponding to FIG. 2.

Die in der Zeichnung ausschnittsweise dargestellte Rohrweiche ist für eine Zweizylinder-Dickstoffpumpe bestimmt, deren nicht dargestellte Förderzylinder an ihren MÜdungen auf der Seite eines Materialaufgabebehälters durch eine auswechselbare Brillenplatte 5 abgedeckt sind. Auf der Seite des Materialaufgabebehälters ist ein Schwenkrohr 2 mit seiner Stirnseite vor der Brillenplatte 5 um ein horizontale Achse so hin- und herverschwenkbar angeordnet, daß ihre Öffnung 20 abwechselnd vor die eine oder andere der beiden Öfnungen 4 der Brillenplatte 5 gelangt und die andere Öffnung 4 zum Materialaufgabebehälter freigibt. An seinem der Brillenplatte gegenüberliegenden Ende mündet das Schwenkrohr 2 in eine nicht dargestellte Förderleitung. Für den druckdichten stirnseitigen Anschluß der Rohrweiche an die Brillenplatte 5 ist auf der zylindrischen Führungs- und Zentrierfläche 7 des Schuenkrohrs 2 ein Verschleißring 1 mit seiner zylindrischen Axialführungsfläche 21 axial verschiebbar gelagert. An seinem stirnseitigen Ende weist der Verschleißring 1 einen radial nach innen weisenden Ringansatz 22 auf, dessen äußere Stirnfläche 23 gegen die Oberfläche 24 der Brillenplatte 5 anliegt und dessen ringförmige Innenfläche 17 der Stirnfläche 16 des Schwenkrohrs 2 gegenüberliegt.The pipe switch shown in the drawing is intended for a two-cylinder thick matter pump, the delivery cylinders, not shown, of which are covered by a replaceable spectacle plate 5 on their mouths on the side of a material feed container. On the side of the material feed container, a swivel tube 2 is arranged with its end face in front of the spectacle plate 5 so that it can swivel back and forth about a horizontal axis in such a way that its opening 20 alternately reaches one or the other of the two openings 4 of the spectacle plate 5 and the other opening 4 releases to the material feed container. At its end opposite the spectacle plate, the swivel tube 2 opens into a delivery line, not shown. For the pressure-tight frontal connection of the tube switch to the spectacle plate 5, a wear ring 1 with its cylindrical axial guide surface 21 is axially displaceably mounted on the cylindrical guide and centering surface 7 of the shoe tube 2. At its front end, the wear ring 1 has a radially inwardly facing ring shoulder 22, the outer end face 23 of which against the surface 24 of the spectacle plate 5 rests and the annular inner surface 17 of which lies opposite the end face 16 of the swivel tube 2.

Im Bereich des stirnseitigen Endes des Schwenkrohrs 2 befindet sich eine rechteckige Stufeneindrehung 6, durch die der Außendurchmesser 7 des Schwenkrohrs auf den Außendurchmesser 8 verkleinert wird. Dadurch ergibt sich zwischen dem stirnseitigen Ende des Schwenkrohrs 2 und den benachbarten Innenflächen des Verschleißrings 1 ein im Querschnitt rechteckiger Ringraum, in welchem ein gummielastischer Ring 3 unter Vorspannung angeordnet ist. Der Ring 3 liegt mit seiner radialen Innenfläche gegen die radialen Begrenzungsfläche 8 und mit seiner rückwärtigen Stirnfläche 12′ gegen die axiale Stufe 6 der Eindrehung in der Rohrweiche 2 an, während er mit seiner radialen Außenfläche gegen den die Eindrehung überbrückenden Teil der Axialführungsfläche 21 des Verschleißrings 1 und mit seiner vorderen Stirnfläche 12 gegen den radial außenliegenden Teil der inneren Ringfläche 17 des Verschleißrings 1 anliegt. Die Stirnfläche 16 des Schwenkrohrs 2 ist durch radial durchgehende, axial offene Nuten 11 oder einen Ringspalt 18 von der Innenfläche 17 des Verschleißrings 1 getrennt, so daß das unter Druck durch das Schwenkrohr 2 geförderte dickflüssige Fördergut von innen her unmittelbar zu dem die Nuten 11 bzw. den Spalt 18 überbrückenden Teil des elastischen Rings 3 gelangen kann. Im Falle der Fig. 1a schlägt das Schwenkrohr 2 mit der Oberkante der Nuten 11 im Bereich der Innenfläche 17 gegen den Verschleißring 1 an, während im Falle der Fig. 2 und 3 im rückwärtigen Bereich des Schwenkrohrs 2 eine Stufe 15 als Begrenzungsanschlag für den Verschleißring 1 vorgesehen ist. Bei Druckbeaufschlagung wird das dickflüssige Fördergut durch die Nuten 11 bzw. den Ringspalt 18 hindurch gegen den gummielastischen Ring 3 gepreßt und baut im Ring 3 einen Druck auf, der den hinteren Dichtspalt im Bereich des Zentrierdurchmessers 7 fest verschließt. Um die Nachfederungseigenschaften des Rings 3 zu verbessern, können auf der Innenseite des Rings 3 an beiden Enden Fasen 25 (Fig. 2) oder keilförmige Ringnuten 26 (Fig. 3) vorgesehen werden. Durch die beidseitige Anbringung der Fasen 25 bzw. Ringnuten 26 wird einmal das Nachfederungsvolumen des elastischen Rings 3 vergrößert und zum anderen die Möglichkeit geboten, den Ring 3 im Verschleißfalle umzudrehen und damit seine Lebensdauer zu verdoppeln. Zur Verbesserung der Axialdichtung ist im Falle der Fig. 1a am hinteren Ende des Verschleißrings 1 eine Ringnut 14 zur Aufnahme eines O-Rings 27 angeordnet.In the area of the front end of the swivel tube 2 there is a rectangular step 6, through which the outer diameter 7 of the swivel tube is reduced to the outer diameter 8. This results in an annular space with a rectangular cross section between the front end of the swivel tube 2 and the adjacent inner surfaces of the wear ring 1, in which an elastic ring 3 is arranged under prestress. The ring 3 lies with its radial inner surface against the radial boundary surface 8 and with its rear end face 12 'against the axial step 6 of the turn in the pipe switch 2, while it with its radial outer surface against the part of the axial guide surface 21 of the wear ring bridging the turn 1 and rests with its front end face 12 against the radially outer part of the inner ring face 17 of the wear ring 1. The end face 16 of the swivel tube 2 is separated from the inner surface 17 of the wear ring 1 by radially continuous, axially open grooves 11 or an annular gap 18, so that the viscous conveyed material conveyed under pressure by the swivel tube 2 directly from the inside to the grooves 11 or can reach the gap 18 bridging part of the elastic ring 3. In the case of Fig. 1a, the swivel tube 2 strikes with the upper edge of the grooves 11 in the region of the inner surface 17 against the wear ring 1, while in the case of FIGS. 2 and 3 a step 15 is provided in the rear region of the swivel tube 2 as a limit stop for the wear ring 1. When pressurized, the viscous material to be conveyed is pressed through the grooves 11 or the annular gap 18 against the rubber-elastic ring 3 and builds up a pressure in the ring 3, which tightly closes the rear sealing gap in the region of the centering diameter 7. In order to improve the resilience properties of the ring 3, chamfers 25 (FIG. 2) or wedge-shaped ring grooves 26 (FIG. 3) can be provided on the inside of the ring 3 at both ends. The two-sided attachment of the bevels 25 or ring grooves 26 increases the resilience of the elastic ring 3 on the one hand, and on the other hand offers the possibility of turning the ring 3 in the event of wear and thus doubling its service life. To improve the axial seal, an annular groove 14 for receiving an O-ring 27 is arranged in the case of FIG. 1a at the rear end of the wear ring 1.

Der gummielastische Ring 3 mit seinem im wesentlichen rechteckigen Querschnitt übernimmt neben einer Dichtfunktion aufgrund seiner Varspannung zusätzlich die Funktion einer automatischen Nachführung des Verschleißrings 1 im Verschleißfalle. Außerdem stellt seine radiale Außenfläche eine Verlängerung der axialen Führungs- und Zentrierfläche 21 dar. Wenn - wie bei den gezeigten Ausführungsbeispielen - die axiale Ausdehnung des Rings 3 mindestens das Doppelte, vorzugsweise ein Mehrfaches der axialen Ausdehnung der Führungs- und Zentrierfläche 21 auf dem Schwenkrohr 2 beträgt, so besteht innerhalb des notwendigerweise vorhandenen Spiels zwischen dem Verschleißring 1 und dem Schwenkrohr 2 im Bereich der Zentrierfläche 21 die Möglichkeit, daß der Verschleißring 1 aufgrund der elastischen Eigenschaften des Rings 3 leicht ankippen kann, wenn Feststoffteilchen in den Spaltbereich zwischen den Anlageflächen 23 und 24 des Verschleißrings 1 und der Brillenplatte 5 gelangen. Dadurch ergibt sich eine erhebliche Verschleißminderung und somit eine höhere Lebensdauer des Verschleißrings 1 und der Brillenplatte 5.The rubber-elastic ring 3 with its essentially rectangular cross-section takes on not only a sealing function due to its var tension but also the function of automatic tracking of the wear ring 1 in the event of wear. In addition, its radial outer surface represents an extension of the axial guide and centering surface 21. If - as in the exemplary embodiments shown - the axial extent of the ring 3 is at least twice, preferably one Multiple of the axial extent of the guide and centering surface 21 on the swivel tube 2, there is the possibility within the necessary play between the wear ring 1 and the swivel tube 2 in the area of the centering surface 21 that the wear ring 1 due to the elastic properties of the ring 3 can tilt easily if solid particles get into the gap area between the contact surfaces 23 and 24 of the wear ring 1 and the spectacle plate 5. This results in a considerable reduction in wear and thus a longer service life of the wear ring 1 and the spectacle plate 5.

Wie aus Fig. 1b zu ersehen ist, sind die mit dem hydrostatischen Druck beaufschlagten Ringflächen 23 und 17 des Verschleißrings 1 so angeordnet und ausgebildet, daß die in anpressender Richtung wirkende Kraft 31 größer als die abhebende Kraft 30 ist. Hinzu kommt, daß der Wirkdurchmesser 10 der zwischen dem Schwenkrohr 2 und dem Verschleißring 1 in anpressender Richtung wirkenden Kraft 31 größer ist, als der Wirkdurchmesser 9 der zwischen der Brillenplatte 5 und dem Verschleißring 1 in abhebender Richtung wirkenden Kraft 30. Weiter ist der axiale Führungs- und Zentrierdurchmesser 7 des Verschleißrings 1 größer als der Wirkdurchmesser 9, mit welchem der Verschleißring 1 an der Brillenplatte 5 anliegt und sogar größer als der stirnseitige Außendurchmesser des Ringansatzes 22, mit welchem der Verschleißring 1 an der Brillenplatte 5 anliegt.As can be seen from FIG. 1b, the ring surfaces 23 and 17 of the wear ring 1, which are acted upon by the hydrostatic pressure, are arranged and designed such that the force 31 acting in the pressing direction is greater than the lifting force 30. In addition, the effective diameter 10 of the force 31 acting between the swivel tube 2 and the wear ring 1 in the pressing direction is greater than the effective diameter 9 of the force 30 acting between the spectacle plate 5 and the wear ring 1 in the lifting direction. Next is the axial guide - And centering diameter 7 of the wear ring 1 larger than the effective diameter 9, with which the wear ring 1 rests on the eyeglass plate 5 and even larger than the end outer diameter of the ring shoulder 22, with which the wear ring 1 rests on the eyeglass plate 5.

Claims (11)

1: Pipe shunt for a two-cylinder pump for viscous fluids having a pivot pipe (2) pivotable in front of a goggle plate (5) on the cylinder, having a wearing ring (1) displaceably arranged on the goggle end of the pivot pipe (2) and pressed against the goggle plate (5) by means of the hydrostatic internal pressure within the pivot pipe (2), and with a rubber-elastic ring (3) arranged between the pivot pipe and the wearing ring, in which respect the wearing ring comprises at its end near the pivot pipe an axial guide surface, which is guided on a radially outward facing cylindrical centring surface of the pivot pipe and together with the centring surface defines a sealing gap, and at its goggle end an annular seat (22), which faces from the axial guide surface radially inwards and the front-end exterior surface of which abuts the goggle plate and the inside surface serving as axial abutment of the rubber-elastic ring (3) is separated from the end surface of the pivot pipe (2) by an axial intermediate space, which is bridged by the rubber-elastic ring and open towards the pipe interior, and whereby the pivot pipe (2) has at its front end a recess which internally reaches underneath the sealing ring, preferably in the shape of a rectangular step and open towards the axial guide surface characterised in that the annular seat (22) is arranged step-free towards the pipe interior in the region of its inside surface (17) serving as abutment of the rubber-elastic ring (3), and that the seat (6, 8) in the pivot pipe (2) reaches underneath the rubber-elastic ring (3) over at least one third of its axial extent.
2: Pipe shunt according to claim 1, characterised in that the seat (6, 8) in the pivot pipe reaches underneath the rubber-elastic ring (3) over at least half, preferably at least two thirds of its axial extent.
3: Pipe shunt according to claim 1 or 2, characterised in that radially passing, axially open grooves (11) are arranged at the frontal end of the pivot pipe (2), the upper edges of which form a front-ended abutment of the pivot pipe (2) against the annular seat (22) of the wearing ring (1).
4: Pipe shunt according to one of claims 1 to 3, characterised in that the pivot pipe (2) has at the rear end of its cylindrical guide and centring surface (7) a stepped abutment (15) for the wearing ring (1), and that the gap (10) between the annular seat (22) of the wearing ring (1) and the end surface (16) of the pivot pipe (2) remains open with the wearing ring (1) abutting.
5: Pipe shunt according to one of claims 1 to 4, characterised in that an annular groove (14) for receiving an O-ring (27) is recessed in the portion of the axial guide surface (21) of the wearing ring (1) opposite the pivot pipe (2), or in the portion of the axial guide and centring surface (7) of the pivot pipe (2) opposite the wearing ring (1).
6: Pipe shunt according to one of claims 1 to 5, characterised in that the diameter (7) of the axial guide surface (21) of the wearing ring (1) is larger than the effective diameter (9) with which the wearing ring (1) abuts the goggle plate.
7: Pipe shunt according to one of claims 1 to 6, characterised in that the diameter (7) of the axial guide surface (21) of the wearing ring (1) is larger than the front-sided outside diameter of the annular seat (22) with which the wearing ring (1) abuts the goggle plate (5).
8: Pipe shunt according to claims 1 to 7, characterised in that the hydrostatically pressurised annular surfaces (23, 17) of the wearing ring (1) are arranged so that the effective diameter (10̸) of the force (31) acting in the press-on direction on the pivot pipe (2) and the wearing ring (1) is greater than the effective diameter (9) of the force (30̸) acting in the lift-off direction between the goggle plate (5) and the wearing ring (1).
9: Pipe shunt according to one of claims 1 to 8, characterised in that the longitudinal extent of the axial guide surface in the region of the rubber-elastic ring (3) is at least twice as that of the axial guide and centring surface (7) in the region of the pivot pipe (2).
10̸: Pipe shunt according to one of claims 3 to 9, characterised in that the rubber-elastic ring (3) has at its end bridging the annular gap (13) or the grooves (11) respectively a radially internal chamfer (25) or wedge-shaped annular groove (26) at
11: Pipe shunt according to claim 10̸, characterised in that the rubber-elastic ring (3) has a respective radially internal chamfer (25) or wedge-shaped annular groove (26) on both ends.
EP89908693A 1988-07-19 1989-07-08 Pipe shunt for a two-cylinder pump for viscous fluids Expired - Lifetime EP0425567B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3824466A DE3824466A1 (en) 1988-07-19 1988-07-19 MULTI-CYLINDER FUEL PUMP
DE3824466 1988-07-19

Publications (2)

Publication Number Publication Date
EP0425567A1 EP0425567A1 (en) 1991-05-08
EP0425567B1 true EP0425567B1 (en) 1992-10-07

Family

ID=6359025

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89908693A Expired - Lifetime EP0425567B1 (en) 1988-07-19 1989-07-08 Pipe shunt for a two-cylinder pump for viscous fluids

Country Status (4)

Country Link
EP (1) EP0425567B1 (en)
JP (1) JP2514729B2 (en)
DE (2) DE3824466A1 (en)
WO (1) WO1990001117A1 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3905355C2 (en) * 1989-02-22 1994-06-23 Schlecht Karl Diverter for two-cylinder thick matter pumps
US5302094A (en) * 1988-07-19 1994-04-12 Putzmeister-Werk Maschinenfabrik Gmbh Tube switch for a double-cylinder sludge pump
KR100390483B1 (en) * 1995-12-13 2003-09-06 엘지전자 주식회사 Method for canceling ghost of tv
DE10131784A1 (en) * 2001-07-04 2003-01-16 Putzmeister Ag Device for conveying flowable and pourable material
EP1580035B1 (en) 2004-03-26 2007-05-30 Continental Aktiengesellschaft Pneumatic tire
GB2416569A (en) 2004-07-27 2006-02-01 Clarke Uk Ltd Method of and a pump for pumping drill cuttings
DE102013215990A1 (en) * 2013-08-13 2015-02-19 Putzmeister Engineering Gmbh Two-cylinder thick matter pump with diverter

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2614895C3 (en) * 1976-04-07 1987-01-22 Karl Dipl.-Ing. 7000 Stuttgart Schlecht Concrete pump pipe switch
DE2829181A1 (en) * 1978-07-03 1980-01-17 Scheele Maschf W Swivel tube connecting concrete pump cylinders - has wear ring sealingly pressurised onto wear plate by hydraulic oil or grease pressure
DE2921735A1 (en) * 1979-05-29 1980-12-04 Teka Baumaschinen Gmbh Twin cylinder type concrete pump - has seal on swivel pipe hydraulically loaded by pressure in pipe through flexible membrane
DE3153268C2 (en) * 1981-01-31 1988-01-28 Friedrich Wilh. Schwing Gmbh, 4690 Herne, De Two-cylinder viscous-material pump, preferably concrete pump
JPS59172287U (en) * 1983-05-06 1984-11-17 石川島播磨重工業株式会社 Concrete pump seal structure

Also Published As

Publication number Publication date
JPH03506060A (en) 1991-12-26
WO1990001117A1 (en) 1990-02-08
DE58902434D1 (en) 1992-11-12
DE3824466A1 (en) 1990-01-25
EP0425567A1 (en) 1991-05-08
JP2514729B2 (en) 1996-07-10

Similar Documents

Publication Publication Date Title
DE3153268C2 (en) Two-cylinder viscous-material pump, preferably concrete pump
EP0188730B1 (en) Diaphragm pump with a hydraulically actuated rolling membrane
DE2903749C2 (en) Piston pump with an S-shaped swivel tube
DE1288392B (en) Rotary valve
DE3611952C2 (en) Piston pump with improved sealing
EP2387667A1 (en) Method for feeding pasty masses and pump device for feeding pasty masses
EP0425567B1 (en) Pipe shunt for a two-cylinder pump for viscous fluids
DE3113787C2 (en) Transfer tube for concrete or thick matter piston pumps
DE3232083C2 (en)
EP0052192A1 (en) Apparatus for concrete pumps
DE69303376T2 (en) PIPE DIVERTER FOR A TWO-CYLINDER FUEL PUMP
EP0464165B1 (en) Ultrahigh pressure plunger pump
DE2415276B1 (en) Pump for pumping thick matter, especially concrete
DE3410211A1 (en) DEVICE FOR SEALING A CONCRETE PUMP
EP0551590A1 (en) High-pressure plunger pump, working preferably at pressures above 2000 bars
DE3430193A1 (en) SWIVEL TUBE SYSTEM FOR CONCRETE PUMPS
EP1053401B1 (en) Tubular branching system for dual-cylinder thick-liquid pump
DE1503390A1 (en) Hydraulic diaphragm pump
DE3905355C2 (en) Diverter for two-cylinder thick matter pumps
EP0112404A1 (en) Two cylinder viscous liquid pump, especially a concrete pump
DE3904862A1 (en) Tube switch for twin-cylinder viscous-material pumps
EP3014121A1 (en) Switchover device for a thick matter pump
DE2851354A1 (en) Concrete pump with swivelling delivery tube - has wear ring floatingly pressurised on to ported plate at end of pump cylinder
DE3931487A1 (en) SEALING FOR PISTON IN AXIAL PISTON MACHINES
DE1918609A1 (en) Slip ring

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: 19900723

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB IT NL

17Q First examination report despatched

Effective date: 19910916

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT NL

REF Corresponds to:

Ref document number: 58902434

Country of ref document: DE

Date of ref document: 19921112

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
ET Fr: translation filed
ITF It: translation for a ep patent filed
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

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

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

Ref country code: FR

Payment date: 20020610

Year of fee payment: 14

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

Ref country code: GB

Payment date: 20020612

Year of fee payment: 14

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

Ref country code: NL

Payment date: 20020619

Year of fee payment: 14

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 NON-PAYMENT OF DUE FEES

Effective date: 20030708

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

Ref country code: DE

Payment date: 20030725

Year of fee payment: 15

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 NON-PAYMENT OF DUE FEES

Effective date: 20040201

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20030708

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

Ref country code: FR

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

Effective date: 20040331

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20040201

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

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

Ref country code: DE

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

Effective date: 20050201

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

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050708