EP1013943A1 - Dispositif de fin-de-courses pour vérins à fluide - Google Patents

Dispositif de fin-de-courses pour vérins à fluide Download PDF

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Publication number
EP1013943A1
EP1013943A1 EP98650090A EP98650090A EP1013943A1 EP 1013943 A1 EP1013943 A1 EP 1013943A1 EP 98650090 A EP98650090 A EP 98650090A EP 98650090 A EP98650090 A EP 98650090A EP 1013943 A1 EP1013943 A1 EP 1013943A1
Authority
EP
European Patent Office
Prior art keywords
piston
cylinder
pressure chamber
contacting device
washer
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.)
Withdrawn
Application number
EP98650090A
Other languages
German (de)
English (en)
Inventor
Patrick Joseph Byrne
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to EP98650090A priority Critical patent/EP1013943A1/fr
Publication of EP1013943A1 publication Critical patent/EP1013943A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/20—Other details, e.g. assembly with regulating devices
    • F15B15/28—Means for indicating the position, e.g. end of stroke
    • F15B15/2807—Position switches, i.e. means for sensing of discrete positions only, e.g. limit switches

Definitions

  • the invention relates to a hydraulic or pneumatic cylinder and in particular to a cylinder having an outer housing and an inner piston which is movable through the housing.
  • An electrical signal is provided from within the pressure chamber(s) of the cylinder depending on the axial position of the piston within the cylinder.
  • the cylinder is of the type having a sensing device physically located within the pressure chamber to sense the position of the piston and a contacting device which operates the sensing device when the piston is at a predetermined position in the housing.
  • a low voltage electric supply is connected to the sensing device but electrically insulated from the main cylinder body.
  • a second electrical connection is made to the cylinder body.
  • Cylinders of this type are known.
  • the operation of the sensing device and associated contact device shortens the stroke length of the piston. Consequently the cylinder housings are relatively long to achieve the necessary switching with a given stroke. This is a technically important disadvantage as often there are severe space limitations in the installation of such cylinders for specific applications.
  • a cylinder having:-
  • the invention provides a cylinder in which a reliable signal is provided from within the pressure chamber(s) of a hydraulic or pneumatic cylinder, at a desirable point before a moving piston reaches its end position but allowing the piston to complete its full travel without sacrificing stroke length or alternatively demanding additional overall assembly length in order to obtain a particular stroke length.
  • the contacting device is biassed between a retracted position and an extended position.
  • the contacting device is spring biassed from the retracted to the extended position.
  • the contact device is a secondary plunger mounted within the piston for movement between the retracted and extended positions.
  • the sensing device includes a contact pin which extends into the pressure chamber for engagement with the contacting device.
  • the contacting device includes a flange for contacting the contact pin of the sensing device.
  • the flange is provided by a washer.
  • the flange or washer extends outwardly of a sleeve which is slidably movable relative to the piston when the flange or washer engages a contact pin.
  • the cylinder has a full bore side sensing device with an associated full bore side contacting device and an annular side sensing device with an associated annular side contacting device.
  • the full bore sensing device comprises a secondary plunger mounted within the piston for movement between a retracted and an extended position and a flange or washer mounted to the secondary plunger for engagement with a full bore contact pin extending into the pressure chamber.
  • the annular side sensing device comprises a sleeve mounted to the piston for movement between a retracted and or extended position and a flange or washer mounted to the sleeve, for engagement by an annular contact pin extending into the pressure chamber.
  • a cylinder in this case an hydraulic cylinder 1 according to the invention having an outer housing 2 defining a pressure chamber and an inner piston 3 which is slidably movable through the pressure chamber.
  • the housing 2 has main oil ports 4, 5, for the pressure chamber.
  • An electrical signal is provided from within the pressure chamber depending on the axial position of the piston 3 within the chamber.
  • a low voltage electrical supply is connected to a sensing device which is physically located within the pressure chamber but is electrically insulated from the cylinder housing.
  • a second connection is electrically connected to the cylinder housing 2.
  • the piston 3 carries a contacting device which completes the circuit and provides a control signal when the piston 3 has reached a predetermined position within its stroke.
  • the electrical circuit is manipulated as between the normally "open” position and a selected "closed” position.
  • the control signal is generated at a predetermined desired position before the piston 3 reaches the end of its stroke.
  • the travel of the piston 3 is not restricted and the piston may continue to its full travel without sacrifice of its normal stroke.
  • an advance control signal is provided without any loss of stroke or any requirement to lengthen the cylinder.
  • the cylinder has an annular side switch housing 10 and a full bore side switch housing 11 from which switching signals are directed to operate the cylinder 1 and/or associated equipment.
  • the switch housing 10 contains an annular side sensing device, which in this case is in the form of an annular contact pin 15.
  • the contact pin 15 is engaged by an annular side contact device which in this case is a flange provided by a washer 16.
  • the washer 16 is movable along a sleeve 18 slidably carried by the piston 3.
  • the washer 16 is biassed into the extended position illustrated in Fig. 1A by a coil spring 19 extending around the sleeve 18.
  • the sleeve 18 is, in turn, slidably movable along a step formation 20 of the piston 3.
  • An end cap 25 of the cylinder 1 is sealingly engaged in the housing 2 and includes an axially protecting ring 26 to engage the washer 16 as the piston 3 moves towards the annular closed position.
  • the contact pin 15 extends axially just beyond the ring 26 so that the pin 15 is first engaged by the washer 16 to make a switching contact.
  • the washer 16 is mounted for self alignment to remain in contact with the pin 15 as the piston 3 moves to the left in Fig. 1A and the ring 26 pushes the washer 16 against the biassing of the spring 19.
  • the piston 3 may continue its travel through the housing 2 to maximise the stoke of the piston.
  • the washer 16 moves back along the sleeve 18 until the sleeve 18 contacts the end cap 25.
  • the sleeve 18 is further slidably movable relative to the piston 3 as illustrated particularly in Figs 2A and 3A. In this way switching contact is maintained without interruption of the stoke of the piston.
  • the switch housing 11 contains a full bore side sensing device, which in this case is in the form of a full bore contact pin 30.
  • a fixed land 35 is also provided opposite to the contact pin 31.
  • the contact pin 30 is engaged by a full bore contact device which in this case is provided by an auxiliary plunger 31 co-axial with the piston 3 and extending axially therefrom.
  • the plunger 31 is spring biassed by a coil spring 32 into a normally extended position illustrated in Fig. 1A.
  • the plunger 31 has a step formation at a free end to receive a washer 33 which is held in place by a circlip 34.
  • the auxiliary plunger 31 is slidably movable against the biassing of the spring 32 when the washer 33 contacts the contact pin 30.
  • the land 35 assists in aligning the washer 33 to maintain contact with the pin 30.
  • the piston 3 is free to continue its stroke as the plunger 31 moves into the piston 3 as illustrated in Fig. 5C. In this way the stroke of the piston 3 is maximised as there is no interruption or shortening of the stoke by engaging and maintaining the full bore contact.
  • an "advance" signal can be provided without any undesirable loss of stoke or alternative overall lengthening of the cylinder.
  • the invention provides a hydraulic cylinder with exceptionally efficient switching, especially on the full bore side which does not adversely effect the stoke of the piston.
  • the cylinder is relatively short and may therefore be used in a very wide range of applications, especially where there are space limitations.
  • the cylinder may be used in a wide variety of application in which the cylinder requires to be controlled from an external source to be brought to a halt or reversed in motion, for example to achieve a reciprocating motion.
  • the cylinder may be used, for example, in a compacting machine or a digging device.
  • the cylinder may also be used with a personnel lift, in which case a signal is required to actuate a security device.
EP98650090A 1998-12-22 1998-12-22 Dispositif de fin-de-courses pour vérins à fluide Withdrawn EP1013943A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP98650090A EP1013943A1 (fr) 1998-12-22 1998-12-22 Dispositif de fin-de-courses pour vérins à fluide

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP98650090A EP1013943A1 (fr) 1998-12-22 1998-12-22 Dispositif de fin-de-courses pour vérins à fluide

Publications (1)

Publication Number Publication Date
EP1013943A1 true EP1013943A1 (fr) 2000-06-28

Family

ID=8235875

Family Applications (1)

Application Number Title Priority Date Filing Date
EP98650090A Withdrawn EP1013943A1 (fr) 1998-12-22 1998-12-22 Dispositif de fin-de-courses pour vérins à fluide

Country Status (1)

Country Link
EP (1) EP1013943A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004068520A1 (fr) * 2003-01-31 2004-08-12 Freni Brembo S.P.A. Commutateur
WO2011060876A1 (fr) * 2009-11-21 2011-05-26 Robert Bosch Gmbh Dispositif de rupture de croûte
CN102943784A (zh) * 2012-11-19 2013-02-27 湖南特力液压有限公司 缸筒、液压缸及包含该液压缸的泵送设备
JP2013523421A (ja) * 2010-03-25 2013-06-17 マガリ、ハダル フォース・バリア機構
CN106041795A (zh) * 2016-08-04 2016-10-26 北京长峰广播通讯设备有限责任公司 一种大功率发射机用气动装置

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1117960B (de) * 1960-02-18 1961-11-23 Alois Siebeck Dipl Ing Ventil od. dgl. mit Antrieb durch ein Druckmittel und Anzeige der Endstellungen des Verschlussstuecks mittels Schaltern
DE2538547A1 (de) * 1974-08-30 1976-03-11 Jean Pierre Geoffray Druckzylinder mit eingebauter abtasteinrichtung fuer das arbeitshubende
EP0466273A1 (fr) * 1990-07-09 1992-01-15 Applied Power Inc. Vérin commandé par pression, comportant au moins une paire d'éléments de contact agissant comme interrupteur fin de course du piston

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1117960B (de) * 1960-02-18 1961-11-23 Alois Siebeck Dipl Ing Ventil od. dgl. mit Antrieb durch ein Druckmittel und Anzeige der Endstellungen des Verschlussstuecks mittels Schaltern
DE2538547A1 (de) * 1974-08-30 1976-03-11 Jean Pierre Geoffray Druckzylinder mit eingebauter abtasteinrichtung fuer das arbeitshubende
EP0466273A1 (fr) * 1990-07-09 1992-01-15 Applied Power Inc. Vérin commandé par pression, comportant au moins une paire d'éléments de contact agissant comme interrupteur fin de course du piston

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004068520A1 (fr) * 2003-01-31 2004-08-12 Freni Brembo S.P.A. Commutateur
US7318313B2 (en) 2003-01-31 2008-01-15 Freni Brembo S.P.A. Switch
WO2011060876A1 (fr) * 2009-11-21 2011-05-26 Robert Bosch Gmbh Dispositif de rupture de croûte
US9080245B2 (en) 2009-11-21 2015-07-14 Aventics Gmbh Crust breaking device
AU2010321267B2 (en) * 2009-11-21 2016-01-07 Aventics Gmbh Crust breaking device
JP2013523421A (ja) * 2010-03-25 2013-06-17 マガリ、ハダル フォース・バリア機構
CN102943784A (zh) * 2012-11-19 2013-02-27 湖南特力液压有限公司 缸筒、液压缸及包含该液压缸的泵送设备
CN102943784B (zh) * 2012-11-19 2015-06-10 湖南特力液压有限公司 缸筒、液压缸及包含该液压缸的泵送设备
CN106041795A (zh) * 2016-08-04 2016-10-26 北京长峰广播通讯设备有限责任公司 一种大功率发射机用气动装置
CN106041795B (zh) * 2016-08-04 2017-11-10 北京长峰广播通讯设备有限责任公司 一种大功率发射机用气动装置

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