EP1302673A1 - Zylinder mit variabler Hublänge - Google Patents

Zylinder mit variabler Hublänge Download PDF

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Publication number
EP1302673A1
EP1302673A1 EP02020943A EP02020943A EP1302673A1 EP 1302673 A1 EP1302673 A1 EP 1302673A1 EP 02020943 A EP02020943 A EP 02020943A EP 02020943 A EP02020943 A EP 02020943A EP 1302673 A1 EP1302673 A1 EP 1302673A1
Authority
EP
European Patent Office
Prior art keywords
cylinder head
piston
disk
head
hole
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Withdrawn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
EP02020943A
Other languages
English (en)
French (fr)
Inventor
Luciano Migliori
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
Publication of EP1302673A1 publication Critical patent/EP1302673A1/de
Withdrawn legal-status Critical Current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
    • F15B15/24—Other details, e.g. assembly with regulating devices for restricting the stroke
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/20—Other details, e.g. assembly with regulating devices
    • F15B15/22—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke
    • F15B15/223—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke having a piston with a piston extension or piston recess which completely seals the main fluid outlet as the piston approaches its end position

Definitions

  • This invention refers to single-acting and double-acting pneumatic cylinders having a piston chamber and a reciprocable piston member, provided with a stroke control system for controlling or varying the working stroke of the piston member in cylinders used, for example, for controlling clamping devices of the lever type, normally used for clamping work pieces or locking the same to a supporting structure, in particular for welding mechanical operations or on parts of a structure or of the body of motor vehicles.
  • a conventional pneumatic cylinder as shown in US-A-3,805,672, US-A-3,440,930, EP-A0 005 407, comprises a tubular casing which defines a piston chamber for a reciprocable piston member, which is closed by a fore and rear cylinder head; the piston member of the cylinder is generally provided with a piston rod which protrudes from and is guided by the fore cylinder head.
  • the piston member of conventional pneumatic cylinders usually move along a fixed working stroke and the current tendency is to standardise their dimensions, according to pre-established requirements; consequently it is not possible to vary their working stroke unless to provide the cylinders with particular devices.
  • DE-A-29 811 901 A solution is shown in DE-A-29 811 901, in which use is made of a disk-shaped member, movable inside the piston chamber by means of an adjusting screw, which can be positioned close to or at a certain distance from the rear cylinder head.
  • This system has the main disadvantage of transmitting all the impact forces caused by the piston, when the latter moves backwards, onto the adjusting screw; moreover, it is a complex system which can present functional problems at mechanical level.
  • the pneumatic cylinders are also provided, both in the fore and in the rear heads, with a pneumatic damping system which comprises a suitably set venting path which allows the air to escape in the last portion of the backward or forward working movement of the piston member, so as to reduce its speed and deaden the impact forces.
  • the venting path of a conventional damping device may be provided with a suitable restricted flow passage, or can be provided with a needle valve which can be adjusted in order to vary, as required, the braking speed of the piston in the last portion of its stroke and, consequently, the impact force.
  • the device for controlling or varying the stroke of the piston member has the drawback of not allowing the use of a control valve for adjusting the venting of the air, in that an air space is formed between the disk member and the cylinder head, which would nullify the effect of the control valve.
  • the main object of this invention is to provide a pneumatic cylinder of the type referred to, provided with a system for varying the working stroke of the piston member, which allows the use of a venting device provided with a control valve and which is structurally simple and adaptable to various requirements.
  • the pneumatic cylinder 10 comprises a central tubular casing 11 which forms a chamber 12 for a reciprocable piston member 13; the piston chamber 12 is closed at both ends by a fore head 14 and by a rear head 15.
  • Each cylinder head 14, 15 presents a respective air inlet/outlet hole 16, 17 for pressurized air, which communicates with the piston chamber 12 through passages in the same cylinder heads; in particular, with regard to the rear head 15, the air inlet/outlet hole 17 communicates with a central cavity 19 in the same head, which opens out towards the piston chamber 12.
  • the piston member 13 reciprocates along a working stroke inside the piston chamber 12 and is provided with a piston rod 20 which protrudes from the fore cylinder head 14, forming a seal on an annular gasket 21; the piston member 13, on the side facing the rear head 15, is provided with a closing member or conical plug 22 designed to tightly penetrate into the central cavity 19 of the rear head 15, to form a seal against an annular gasket 24 and to close an air venting duct 25a in the last portion of the working stroke of the piston 13.
  • the plug member 22 and/or the central cavity 19, once they are coupled together, provide a slightly conical gape to allow the passage of air.
  • the rear head 15 is also provided with a pneumatic damping device, capable of dampening the speed and the impact forces of the piston member 13; said damping device comprises a venting duct 25a, which on a side opens out indirectly towards the piston chamber 12, through the central cavity 19, and a side hole 27 comprising a flow control valve 26, such has a needle valve adjustable from the outside through the side hole 27, so as to vary the speed and the impact forces of the piston member 13.
  • the damping device comprises a second venting hole 25b, branched from the hole 27, which directly open into the piston chamber 12, on a side of the central cavity 19.
  • a similar damping device may be also provided in the fore head 14 of the cylinder.
  • head extension means inside the piston chamber 12, for extension of the rear head 15 of the cylinder;
  • said head extension means comprises one or more disk-shaped members 28, in which each disk-shaped member 28 is provided with a central hole 29 axially aligned to, and constituting an extension of the central cavity 19 of the rear head 15, into which the plug member 22 penetrates, to form a seal on an annular gasket 30, fitted in an appropriate annular seat, as shown; moreover, each disk-shaped member 28 is provided on a side with an air venting hole 31, axially aligned with said air venting hole 25b branched from the main venting path 25a, 27.
  • the rear cylinder head 15, at the inner end of the branched off air venting hole 25b, is provided with an annular gasket 32 to form a seal on the facing surface of the disk-shaped member 28 around the venting hole 31 of the latter, so as to allow a sealed connection between the hole 31 and the hole 25b of the venting duct.
  • a further annular gasket 33 is provided on the apposite side of the disk-shaped member 28 at the end of the venting hole 31 facing towards the piston chamber 12, so as to ensure an airtight connection between the venting holes 31 of two or more side by side arranged head extension disks 28.
  • the disks 28 are removably secured to one another and to the rear head 15 by means of at least one fastening screw 34, or by other suitable fastening means, which fits into axially aligned holes 35 in the disk members 30 and into the rear head 15. Since the need may arise, from time to time, to vary the working stroke of the cylinder, according to different values, it is possible to fit more extension disks 28 to extend the rear head 15 and inside the piston chamber 12, in order to achieve greater variability of the stroke, the disks 28 may be of the same thickness or of different thickness.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)
  • Fluid-Damping Devices (AREA)
  • Valve Device For Special Equipments (AREA)
EP02020943A 2001-10-16 2002-09-19 Zylinder mit variabler Hublänge Withdrawn EP1302673A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITMI20012137 2001-10-16
IT2001MI002137A ITMI20012137A1 (it) 2001-10-16 2001-10-16 Cilindro pneumatico a corsa variabile

Publications (1)

Publication Number Publication Date
EP1302673A1 true EP1302673A1 (de) 2003-04-16

Family

ID=11448507

Family Applications (1)

Application Number Title Priority Date Filing Date
EP02020943A Withdrawn EP1302673A1 (de) 2001-10-16 2002-09-19 Zylinder mit variabler Hublänge

Country Status (4)

Country Link
US (1) US20030070541A1 (de)
EP (1) EP1302673A1 (de)
CA (1) CA2404588A1 (de)
IT (1) ITMI20012137A1 (de)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7447689B2 (ja) * 2020-06-10 2024-03-12 Smc株式会社 ガスシリンダ
US11930728B2 (en) 2021-04-29 2024-03-19 Cnh Industrial America Llc Control system for a double-acting air cylinder of an agricultural implement
CN113389767B (zh) * 2021-07-23 2024-06-21 中国科学院合肥物质科学研究院 一种长冲程大缸径结构双作用式气动执行器及其控制系统

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3921504A (en) * 1973-09-27 1975-11-25 Owens Illinois Inc Adjustable stroke invert drive motor for a glass forming machine
US4424737A (en) * 1980-03-26 1984-01-10 Kabushiki Kaisha Komatsu Seisakusho Stroke cushioning apparatus for hydraulic cylinders
DE9104634U1 (de) * 1991-04-16 1991-06-13 De-Sta-Co Metallerzeugnisse Gmbh, 6000 Frankfurt Hubveränderlicher Stellzylinder für den Antrieb von Spannvorrichtungen
US6220588B1 (en) * 1998-06-02 2001-04-24 Tunkers Maschinenbau Gmbh Toggle clamping device or piston cylinder unit

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3067726A (en) * 1961-02-27 1962-12-11 Int Basic Economy Corp Cushioning structure for fluid power cylinders
SE507522C2 (sv) * 1996-10-15 1998-06-15 Mecman Ab Rexroth Tryckfluidcylinder
IT1319005B1 (it) * 2000-10-16 2003-09-19 Luciano Migliori Cilindro pneumatico compatto con dispositivo di ammortizzazione
US6536327B2 (en) * 2001-06-08 2003-03-25 Festo Corporation Double acting cylinder with integral end position volume chambers

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3921504A (en) * 1973-09-27 1975-11-25 Owens Illinois Inc Adjustable stroke invert drive motor for a glass forming machine
US4424737A (en) * 1980-03-26 1984-01-10 Kabushiki Kaisha Komatsu Seisakusho Stroke cushioning apparatus for hydraulic cylinders
DE9104634U1 (de) * 1991-04-16 1991-06-13 De-Sta-Co Metallerzeugnisse Gmbh, 6000 Frankfurt Hubveränderlicher Stellzylinder für den Antrieb von Spannvorrichtungen
US6220588B1 (en) * 1998-06-02 2001-04-24 Tunkers Maschinenbau Gmbh Toggle clamping device or piston cylinder unit

Also Published As

Publication number Publication date
US20030070541A1 (en) 2003-04-17
ITMI20012137A1 (it) 2003-04-16
CA2404588A1 (en) 2003-04-16

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