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WO1998036174A1 - Pressure accumulator - Google Patents

Pressure accumulator Download PDF

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Publication number
WO1998036174A1
WO1998036174A1 PCT/FI1998/000140 FI9800140W WO9836174A1 WO 1998036174 A1 WO1998036174 A1 WO 1998036174A1 FI 9800140 W FI9800140 W FI 9800140W WO 9836174 A1 WO9836174 A1 WO 9836174A1
Authority
WO
WIPO (PCT)
Prior art keywords
pressure
pressure accumulator
accumulator
chamber
reservoir
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.)
Ceased
Application number
PCT/FI1998/000140
Other languages
French (fr)
Inventor
Pekka MÄKYNEN
Raimo MÄKYNEN
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.)
HYDROLL Oy
Original Assignee
HYDROLL Oy
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 HYDROLL Oy filed Critical HYDROLL Oy
Priority to DE69819872T priority Critical patent/DE69819872T2/en
Priority to CA002281786A priority patent/CA2281786C/en
Priority to AU59918/98A priority patent/AU722352B2/en
Priority to EP98903060A priority patent/EP0960278B1/en
Priority to AT98903060T priority patent/ATE254724T1/en
Publication of WO1998036174A1 publication Critical patent/WO1998036174A1/en
Priority to NO19993880A priority patent/NO314363B1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

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
    • F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
    • F15B1/02—Installations or systems with accumulators
    • F15B1/04—Accumulators
    • F15B1/08—Accumulators using a gas cushion; Gas charging devices; Indicators or floats therefor
    • F15B1/24—Accumulators using a gas cushion; Gas charging devices; Indicators or floats therefor with rigid separating means, e.g. pistons
    • 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
    • F15B2201/00—Accumulators
    • F15B2201/20—Accumulator cushioning means
    • F15B2201/205—Accumulator cushioning means using gas
    • 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
    • F15B2201/00—Accumulators
    • F15B2201/30—Accumulator separating means
    • F15B2201/31—Accumulator separating means having rigid separating means, e.g. pistons
    • F15B2201/312—Sealings therefor, e.g. piston rings
    • 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
    • F15B2201/00—Accumulators
    • F15B2201/30—Accumulator separating means
    • F15B2201/315—Accumulator separating means having flexible separating means
    • F15B2201/3151—Accumulator separating means having flexible separating means the flexible separating means being diaphragms or membranes
    • 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
    • F15B2201/00—Accumulators
    • F15B2201/30—Accumulator separating means
    • F15B2201/32—Accumulator separating means having multiple separating means, e.g. with an auxiliary piston sliding within a main piston, multiple membranes or combinations thereof
    • 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
    • F15B2201/00—Accumulators
    • F15B2201/40—Constructional details of accumulators not otherwise provided for
    • F15B2201/415—Gas ports
    • F15B2201/4155—Gas ports having valve means

Definitions

  • the invention relates to a hydraulic accumulator for hydraulic systems.
  • the major disadvantage in present pressure accumulators is that several accumulators are needed in the hydraulic system, whereat the price of the system tends to become too high. Especially, on using double-acting cylinders and hydraulic turning gears two accumulators are needed , one for each direction of motion.
  • the development of double-acting pressure accumulators has been obstructed by technical problems by filling the pressure chamber. Especially, the use of mass- produced ready-machined tubes has been problematic, since in order to get overpressure gas into place, needed between the pistons of a double-acting pressure accumulator, it has been a must to machine and weld the cylinder mantle in spite of the risk of deformation and, accordingly, problems of tightness.
  • Fig. 1 is a schematic representation of a double-acting hydraulic cylinder 20 combined with pressure accumulator 21.
  • Fig. 2 is pressure accumulator 21 in resting position.
  • Fig. 3 is pressure accumulator 21 opened for gas fill.
  • Fig. 4 is pressure accumulator 21 in operating position so that from the left side of the accumulator illustrated in the figure working pressure is directed towards the accumulator.
  • Fig. 5 is pressure accumulator 21 in operating position so that from the right side of the accumulator illustrated in the figure working pressure is directed towards the accumulator.
  • Fig. 6 is pressure accumulator 21 in operating position so that from both sides of the accumulator illustrated in the figure working pressure is directed towards the accumulator.
  • Fig. 7 is a pressure accumulator in the end of which there is a combination of a service and pressure connection.
  • Fig. 8 is a pressure accumulator in the end of which the service connection and the pressure connection are separated.
  • Figure 1 shows a double-acting hydraulic cylinder 20 the pressure connections 22 and 23 corresponding to its working motions in two directions. Accordingly, to these connections the pressure connections 4 and 10 of the double-acting pressure accumulator 21 are connected.
  • the pressure connections 4 and 10 of the double-acting pressure accumulator 21 are connected.
  • the same pressure is directected towards pressure connections 4 or 10 in the pressure accumulator and further to pressure chamber 11 or 12 in the pressure accumulator.
  • the pressure accumulator 21 will take the shocks absorbing them by yielding due to the spring effect of the accumulator.
  • the spring effect of the accumulator is produced in filling the pressure chamber 13 with pressurized gas.
  • FIG. 2 shows schematically the pressure accumulator 21, where it has two separate end chambers 11 and 12.
  • the pressure of the hydraulic system is conveyed to these end chambers from two different spots in the system.
  • Pressure chamber 13 contains high-pressure gas.
  • Pressure chamber 13 is separated from end chambers 11 and 12 by pistons 2 and 5 which are fitted with pressure packings 3 and 6.
  • Piston 5 has a hole 14 running throuhg the piston and joining pressure chamber 13 and pressure chamber 12 together.
  • the gas filling tube 9 and valve 8 are fitted, through which pressure chamber 13 is filled with pressure gas.
  • End part 7 of pressure accumulator 21 is detachable for filling.
  • Figure 3 shows schematically the pressure accumulator 21, where the end part, illustrated in figure 2, has been detached for refill of pressure chamber 13 with pressurized gas.
  • the gas hose of the filling equipment is connected to filling tube 9.
  • Valve 8 is then opened and a proper quantity of gas is let in into chamber 13 and then valve 8 is closed and the end part 7 as per fig. 2 reassembled.
  • Figure 4 shows schematically the pressure accumulator 21 so that in a hydraulic system furnished with pressure accumulator 21, pressure prevails in that part of the system which is connected to end chamber 12 of pressure accumulator 21. Due to pressure piston 5 has moved towards pressure chamber 13 making the gas in the pressure chamber to compress and the pressure to rise further. Due to the spring effect of compressed gas in pressure chamber 13 the hydraulic fluid pressure variations will be received in a favourable way so that the impacts of the shocks get effectively softened and absorbed.
  • Figure 5 shows schematically the pressure accumulator 21 so that in a hydraulic system furnished with pressure accumulator 21, pressure prevails in that part of the system which is connected to the end chamber 11 of pressure accumulator 21. Due to pressure the piston 2 has moved towards pressure chamber 13 making the gas in the pressure chamber to compress and the pressure to rise further. Due to the spring effect of compressed gas in pressure chamber 13 the hydraulic fluid pressure variations will be received in a favourable way so that the impacts of the shocks get effectively softened and absorbed.
  • Figure 6 shows schematically the pressure accumulator 21 so that in any hydraulic system furnished with pressure accumulator 21, pressure prevails in both the system parts whhich are connected to end chamber 11 and 12 of pressure accumulator 21. Due to the pressure piston 2 and piston 5 have moved towarda pressure chamber 13 making the gas in the pressure chamber to compress and the pressure to rise further. Due to the spring effect of compressed gas in pressure chamber 13 the hydraulic fluid pressure variations will be received in a favourable way so that the impacts of the shocks get effectively softened and absorbed.
  • the end part 7 of the illustrated pressure accumulator 21 is furnished with a closing, leak-proof acces hole 16, through which service of the accumulator can be carried out, its function checked and pressure chamber 13 refilled without detaching end part 7 and the pressure pipes. End part 7 is fixed to the end of a tubular pressure connection 10 and the real pressure joint 17 arranged in the side face of this pressure connection 10.
  • a pressure accumulator according to this invention can be accomplished as a piston accumulator as well as a membran accumulator.
  • the accumulator can be a multifunction unit.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Supply Devices, Intensifiers, Converters, And Telemotors (AREA)
  • Braking Systems And Boosters (AREA)
  • Vehicle Body Suspensions (AREA)
  • Reduction Or Emphasis Of Bandwidth Of Signals (AREA)
  • Separation By Low-Temperature Treatments (AREA)

Abstract

A multifunction pressure accumulator (21) comprised of a pressure-proof reservoir having at least two pressure connections (4, 10) and at least two leak-proof partition walls (2, 5) moving or flexing due to pressures conveyed to the reservoir and a pressure chamber formed by means of said partition walls and filled with gas. For filling of pressure chamber (13) the gas filling channel (14) is taken to the pressure chamber side at least through one partition wall.

Description

PRESSURE ACCUMULATOR
The invention relates to a hydraulic accumulator for hydraulic systems.
In hydraulic systems used in vehicles, forest machines, sawing equipment and in a number of other mechanical devices, pressure shocks apperar, due to which components , structures and pipeworks in the system are subjected to hard stress. Mainly, these pressure schocks are caused by stroke-like impacts on hydraulic-driven mechanisms. Since the compression ratio of hydraulic oils is quite small and neither are there any other elasticities in the other system, it is advantageous to use a hydraulic accumulator in the pressure system which, properly dimensioned, takes all pressure peaks and, functioning this way, does not allow the pressure to rise too high in the system, and even the mechnical stress is smaller, so that the hydraulic systems themselves as well as mechanisms needing a hydraulic system can be made lighter in using a pressure accumulator in the hydraulic system.
The major disadvantage in present pressure accumulators is that several accumulators are needed in the hydraulic system, whereat the price of the system tends to become too high. Especially, on using double-acting cylinders and hydraulic turning gears two accumulators are needed , one for each direction of motion. The development of double-acting pressure accumulators has been obstructed by technical problems by filling the pressure chamber. Especially, the use of mass- produced ready-machined tubes has been problematic, since in order to get overpressure gas into place, needed between the pistons of a double-acting pressure accumulator, it has been a must to machine and weld the cylinder mantle in spite of the risk of deformation and, accordingly, problems of tightness.
By means of a pressure accumulator as per this invention a crucial improvement of the above presented disadvantages is achieved. In order to realize this, the pressure accumulator as per this invention is characterized in what is described in the introductory chapter of patent claim 1.
It can be considered the most important advantage of this invention that on using an accumulator as per this invention for a double-acting working cylinder and turning gears only one instead of two accumulators is needed. Due to this fact the system can be purchased at a lower price than before and less space is needed for one accumulator only, the size of space it takes is only a half of the previous volume. There are also less service spots in the system. Further, the weight of the system is smaller, which is of great importance especially for the hydraulic systems of lumber trucks thanks to saved weight and increased load capacity. An advantage of special significance is that in a pressure accumulator as per this invention a favourable ready-machined factory-made cylinder tube can be used that meets the highest demands and whose mantle must neither be machined nor welded, whereat the risk of tube deformation by machining or welding is avoided as well as the risk of leaks in the pressure accumulator.
In the following the invention is disclosed with reference to the enclosed drawing.
Fig. 1 is a schematic representation of a double-acting hydraulic cylinder 20 combined with pressure accumulator 21. Fig. 2 is pressure accumulator 21 in resting position. Fig. 3 is pressure accumulator 21 opened for gas fill. Fig. 4 is pressure accumulator 21 in operating position so that from the left side of the accumulator illustrated in the figure working pressure is directed towards the accumulator. Fig. 5 is pressure accumulator 21 in operating position so that from the right side of the accumulator illustrated in the figure working pressure is directed towards the accumulator.
Fig. 6 is pressure accumulator 21 in operating position so that from both sides of the accumulator illustrated in the figure working pressure is directed towards the accumulator. Fig. 7 is a pressure accumulator in the end of which there is a combination of a service and pressure connection. Fig. 8 is a pressure accumulator in the end of which the service connection and the pressure connection are separated.
Figure 1 shows a double-acting hydraulic cylinder 20 the pressure connections 22 and 23 corresponding to its working motions in two directions. Accordingly, to these connections the pressure connections 4 and 10 of the double-acting pressure accumulator 21 are connected. When working pressure enters either of the hydraulic cylinder 20 pressure connections 22 or 23, the same pressure is directected towards pressure connections 4 or 10 in the pressure accumulator and further to pressure chamber 11 or 12 in the pressure accumulator. When there are pressure shocks on either side of the hydraulic cylinder, the pressure accumulator 21 will take the shocks absorbing them by yielding due to the spring effect of the accumulator. The spring effect of the accumulator is produced in filling the pressure chamber 13 with pressurized gas.
Figure 2 shows schematically the pressure accumulator 21, where it has two separate end chambers 11 and 12. The pressure of the hydraulic system is conveyed to these end chambers from two different spots in the system. Pressure chamber 13 contains high-pressure gas. Pressure chamber 13 is separated from end chambers 11 and 12 by pistons 2 and 5 which are fitted with pressure packings 3 and 6. Piston 5 has a hole 14 running throuhg the piston and joining pressure chamber 13 and pressure chamber 12 together. Into hole 14 the gas filling tube 9 and valve 8 are fitted, through which pressure chamber 13 is filled with pressure gas. End part 7 of pressure accumulator 21 is detachable for filling.
Figure 3 shows schematically the pressure accumulator 21, where the end part, illustrated in figure 2, has been detached for refill of pressure chamber 13 with pressurized gas. For gas refill the gas hose of the filling equipment is connected to filling tube 9. Valve 8 is then opened and a proper quantity of gas is let in into chamber 13 and then valve 8 is closed and the end part 7 as per fig. 2 reassembled.
Figure 4 shows schematically the pressure accumulator 21 so that in a hydraulic system furnished with pressure accumulator 21, pressure prevails in that part of the system which is connected to end chamber 12 of pressure accumulator 21. Due to pressure piston 5 has moved towards pressure chamber 13 making the gas in the pressure chamber to compress and the pressure to rise further. Due to the spring effect of compressed gas in pressure chamber 13 the hydraulic fluid pressure variations will be received in a favourable way so that the impacts of the shocks get effectively softened and absorbed.
Figure 5 shows schematically the pressure accumulator 21 so that in a hydraulic system furnished with pressure accumulator 21, pressure prevails in that part of the system which is connected to the end chamber 11 of pressure accumulator 21. Due to pressure the piston 2 has moved towards pressure chamber 13 making the gas in the pressure chamber to compress and the pressure to rise further. Due to the spring effect of compressed gas in pressure chamber 13 the hydraulic fluid pressure variations will be received in a favourable way so that the impacts of the shocks get effectively softened and absorbed.
Figure 6 shows schematically the pressure accumulator 21 so that in any hydraulic system furnished with pressure accumulator 21, pressure prevails in both the system parts whhich are connected to end chamber 11 and 12 of pressure accumulator 21. Due to the pressure piston 2 and piston 5 have moved towarda pressure chamber 13 making the gas in the pressure chamber to compress and the pressure to rise further. Due to the spring effect of compressed gas in pressure chamber 13 the hydraulic fluid pressure variations will be received in a favourable way so that the impacts of the shocks get effectively softened and absorbed. In figure 7 the end part 7 of the illustrated pressure accumulator 21 is furnished with a closing, leak-proof acces hole 16, through which service of the accumulator can be carried out, its function checked and pressure chamber 13 refilled without detaching end part 7 and the pressure pipes. End part 7 is fixed to the end of a tubular pressure connection 10 and the real pressure joint 17 arranged in the side face of this pressure connection 10.
In figure 8 the closing access hole 16 and the pressure connection are fixed separately from each other in the end part 7 of the illustrated pressure accumulator 21.
Especially, it is worth noting that a pressure accumulator according to this invention can be accomplished as a piston accumulator as well as a membran accumulator. Instead of the double-acting accumulator presented in the introductory chapter, the accumulator can be a multifunction unit. Anyhow, it is worth noting that the above presentetation of the invention is made with reference to only one of its advantageous embodiments. It is by no means meant to confine the invention to this design only but several modifications are possible within the inventional concept determined in the following patent claims.

Claims

PATENT CLAIMS
1. A multifunction pressure accumulator (21) comprised of a pressure-proof reservoir having at least two pressure connections (4,10) and at least two leak-proof partition walls (2), (5) moving or flexing due to pressures conveyed to the reservoir and a pressure chamber (13) formed by means of said partition walls and filled with gas, characterized in that for refill of the pressure chamber (13) the gas filling channel (14) is taken to the pressure chamber side at least through one partition wall.
2. A pressure accumulator according to patent claim 1 characterized in that there is in pressure accumulator (21) reservoir body (7) an access hole (16) through which the pressure in chamber (13) can be measured and gas filled along channel (14) protruding through the partition wall.
3. A pressure accumulator according to patent claim 1 and 2 characterized in that in end part (7) access hole (16) and pressure hole (17) are arranged separately.
4. A pressure accumulator according to patent claim 1 and 2 characterized in that substantially the end part (7) is fitted with a t-branch shaped pressure connection, whereat access hole (16) is directly in the top of connection (10) and pressure connection (17) is the branch connection.
5. A pressure accumulator according to patent claim 1 and 2 characterized in that end part (7) can be detached from reservoir body (15). AMENDED CLAIMS
[received by the International Bureau on 10 July 1998 (10.07.98); original claims 1-5 replaced by new claims 1-4 (1 page )]
1. A multifunction pressure accumulator (21) comprised of a pressure-proof reservoir having at least two pressure connections (4,10) and at least two leak-proof partition walls (2) , (5) moving or flexing due to pressures conveyed to the reservoir and a pressure chamber (13) formed by means of said partition walls and filled with gas, characterized in that for refilling of the pressure chamber (13) the gas filling channel (14) is equipped with a valve (8) and is taken to the pressure chamber side at least through one partition wall.
2. A pressure accumulator according to patent claim 1 characterized in that in the pressure accumulator (21) reservoir body (7) a manhole (16) is fitted through which one can measure the pressure in chamber (13) and carry out gas filling along channel (14) running through the partition wall.
3. A pressure accumulator according to patent claim 1 and 2 characterized in that end part (7) has separately arranged a manhole (16) and pressure hole (17) .
4. A pressure accumulator according to patent claim 1 and 2 characterized in that end part (7) can be opened from reservoir body (15) .
PCT/FI1998/000140 1997-02-14 1998-02-16 Pressure accumulator Ceased WO1998036174A1 (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
DE69819872T DE69819872T2 (en) 1997-02-14 1998-02-16 ACCUMULATORS
CA002281786A CA2281786C (en) 1997-02-14 1998-02-16 Pressure accumulator
AU59918/98A AU722352B2 (en) 1997-02-14 1998-02-16 Pressure accumulator
EP98903060A EP0960278B1 (en) 1997-02-14 1998-02-16 Pressure accumulator
AT98903060T ATE254724T1 (en) 1997-02-14 1998-02-16 PRESSURE MEMORY
NO19993880A NO314363B1 (en) 1997-02-14 1999-08-11 Pressure accumulator

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI970621 1997-02-14
FI970621A FI106399B (en) 1997-02-14 1997-02-14 Pressure

Publications (1)

Publication Number Publication Date
WO1998036174A1 true WO1998036174A1 (en) 1998-08-20

Family

ID=8548202

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1998/000140 Ceased WO1998036174A1 (en) 1997-02-14 1998-02-16 Pressure accumulator

Country Status (8)

Country Link
EP (1) EP0960278B1 (en)
AT (1) ATE254724T1 (en)
AU (1) AU722352B2 (en)
CA (1) CA2281786C (en)
DE (1) DE69819872T2 (en)
FI (1) FI106399B (en)
NO (1) NO314363B1 (en)
WO (1) WO1998036174A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1659295A1 (en) * 2004-11-18 2006-05-24 Parker Hannifin PLC Accumulator
WO2015043117A1 (en) * 2013-09-27 2015-04-02 陈启星 Liquid-trap and filled-piston based liquid seal energy accumulator and hydraulic system thereof

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE202014010304U1 (en) * 2014-03-29 2016-01-22 Anatolij Bolenko Compress air with underwater pressure and double cylinder.
CN110552918B (en) * 2018-05-31 2021-01-12 宝武特种冶金有限公司 Nitrogen supplement control method for hydraulic system of seamless steel pipe hot extrusion production line

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3907001A (en) * 1973-02-12 1975-09-23 Pneumo Dynamics Corp Combination accumulator reservoir

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3467140A (en) * 1965-07-16 1969-09-16 Ralph P Piffath Hermetical sealing mechanism

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3907001A (en) * 1973-02-12 1975-09-23 Pneumo Dynamics Corp Combination accumulator reservoir

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1659295A1 (en) * 2004-11-18 2006-05-24 Parker Hannifin PLC Accumulator
GB2420380A (en) * 2004-11-18 2006-05-24 Parker Hannifin Plc Twin piston gas filled hydraulic actuator
WO2015043117A1 (en) * 2013-09-27 2015-04-02 陈启星 Liquid-trap and filled-piston based liquid seal energy accumulator and hydraulic system thereof

Also Published As

Publication number Publication date
NO993880L (en) 1999-10-14
EP0960278A1 (en) 1999-12-01
DE69819872D1 (en) 2003-12-24
FI106399B (en) 2001-01-31
AU5991898A (en) 1998-09-08
AU722352B2 (en) 2000-07-27
CA2281786A1 (en) 1998-08-20
DE69819872T2 (en) 2004-08-05
FI970621L (en) 1998-08-15
NO314363B1 (en) 2003-03-10
EP0960278B1 (en) 2003-11-19
FI970621A0 (en) 1997-02-14
CA2281786C (en) 2006-08-01
NO993880D0 (en) 1999-08-11
ATE254724T1 (en) 2003-12-15

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