CN100464080C - Oil-pressure driving device of lifting machine - Google Patents

Oil-pressure driving device of lifting machine Download PDF

Info

Publication number
CN100464080C
CN100464080C CNB2006100567811A CN200610056781A CN100464080C CN 100464080 C CN100464080 C CN 100464080C CN B2006100567811 A CNB2006100567811 A CN B2006100567811A CN 200610056781 A CN200610056781 A CN 200610056781A CN 100464080 C CN100464080 C CN 100464080C
Authority
CN
China
Prior art keywords
piston
cylinder body
space
air
hydraulic
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 - Fee Related
Application number
CNB2006100567811A
Other languages
Chinese (zh)
Other versions
CN101033761A (en
Inventor
陈明和
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.)
ACETECH ENTERPRISE CORP
Original Assignee
ACETECH ENTERPRISE CORP
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 ACETECH ENTERPRISE CORP filed Critical ACETECH ENTERPRISE CORP
Priority to CNB2006100567811A priority Critical patent/CN100464080C/en
Publication of CN101033761A publication Critical patent/CN101033761A/en
Application granted granted Critical
Publication of CN100464080C publication Critical patent/CN100464080C/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Actuator (AREA)

Abstract

The invention relates to oil pressure drive device of elevator. It contains a cylinder which locates a plunger and a connecting rod. The plunger has a channel and space which locates a check value and a spring. The spring used to push the value uprising then make one value plg can joint seal to the bottom of channel. The cylinder contains masses of gas and oil. Gas is completely sealed in cylinder. When plunger take reciprocating motion, the gas and oil can create a pressure difference by plunger's extruding. The pressure differnce used to control value plug's start and stop make inclosed gas can flow in whole space of the cylinder. Because of the inclosed gas, cylinder won't be damaged by polluting of external pollutant.

Description

The drive device for hydraulic of elevation and subsidence mechanical
Technical field
The present invention relates to a kind of drive device for hydraulic of elevation and subsidence mechanical, refer in particular to a kind of by the device of airtight cylinder body as the driving device lifting.
Background technique
Oil hydraulic cylinder 7 as shown in figure 11, it is the general normal lifting that is applied to facility such as fork lift truck, automobile lifting machine, it includes a cylinder body 71, a piston 72 and a piston rod 73, and this is respectively equipped with one for the air hole 711 and oilhole 712 of air with the oil turnover above cylinder body 71; In desire one external load 731 is raise when mobile, usually oil is imported in this oil hydraulic cylinder 7 so that this piston 72 moves by the oil pump (not shown), and it is outwards mobile to drive this piston rod 73 simultaneously, impels this load 731 to move on the position that will reach; And above-mentioned driving is simultaneously, the air of piston 72 superjacent air spaces can be discharged in the external world, otherwise, when these piston rod 73 retractions, ambient air is sucked into the inside of this cylinder body 71, and at this moment, the oil in this cylinder body 71 can be extruded and drain back in the outside fuel tank (not shown) that is connect; And this oil hydraulic cylinder 7 is in this way as the driving of external load lifting.
In the process of discharge that air continues and suction, will produce many noises, for solving this problem, usually can on this air hole 711, be equiped with a baffler (not shown), yet this installs the action of this baffler, operational site with fork lift truck, usually have many dusts or aqueous vapor, follow pollutants such as the dust brought into and aqueous vapor in the time of also can't avoiding air to suck, and these pollutants will make this cylinder body 71 be damaged, for example dust can cause the wearing and tearing of inwall when these piston 72 motions, and the aqueous vapor that is introduced into simultaneously also might make the situation of these cylinder body 71 inwall generation corrosions; When if fork lift truck is used in the chemical plant, then can be because of having more corrosive pH value gas or liquid in the chemical plant, and in the process that this oil hydraulic cylinder 7 uses, this type of acrid gas or liquid are to have an opportunity to be brought in this cylinder body 71 by air, so will cause taking place in this cylinder body 71 situation of corrosion.
And for fear of this problem, usually can be in this air hole 711 to being connected with a breathing pipe (not shown) between this fuel tank, hope imports air in this fuel tank by this breathing pipe, to prevent that the air in this cylinder body 71 from contacting with the air in the external world, yet this fuel tank is but because of bearing inserting of additional air, under the condition of limited of fuel tank space, be bound on this fuel tank the installing one air hole (not shown), for leading off of air, though this design is under the lasting use of this oil hydraulic cylinder 7, but the mat air is brought some oil gas in this cylinder body 71 into, the probability that so can appropriateness reduces the damage of these cylinder body 71 inwalls, but because of still being provided with an air hole on this fuel tank, so in the process of importing that air continues and derivation, can't guarantee fully that also this air can not be subjected to pollution; In addition; on oil hydraulic cylinder 7; the normal situation that extraneous work occurs to cooperate; and need this oil hydraulic cylinder 7 is grown the situation that distance moves; at this moment; this breathing pipe of being located on this oil hydraulic cylinder 7 is down mobile what continue, and regular meeting's generation is long because of the length of this breathing pipe, and the difficult puzzlement of arranging of this breathing pipe shallow storage space takes place.
According to the above, as can be known at present in the use field of cylinder body, how therefore the problem of being narrated in existing as mentioned overcome cylinder body because of the situation that the importing of contaminativity air damages, and is the problem that current urgent need is faced in fact.
Summary of the invention
Main purpose of the present invention, be to solve the above problems and a kind of drive device for hydraulic of elevation and subsidence mechanical is provided, it is that the mat pressure difference is used as the mechanism that one-way valve opens and closes, and control the circulation of airtight air with this mechanism, and solve air by this, and then the situation of avoiding inboard wall of cylinder block to damage by the problem of outside contamination.
For achieving the above object, the present invention proposes a kind of drive device for hydraulic, be provided with a passage more than the intermediate portion of its piston, and the bottom of this piston is provided with a containing space; And this passage around this piston inwardly and from top to bottom break-through to this containing space; Be provided with an one-way valve and the elastic element of mat one pressure difference again in this containing space with the control air ventilation; And this elastic element is in order to this one-way valve of pushing tow upwards, so that a valve plug at this one-way valve top can connect airtight the bottom in this passage.
Concrete technological scheme of the present invention is as follows:
A kind of drive device for hydraulic of elevation and subsidence mechanical comprises a cylinder body and a piston rod, and the end of this piston rod in this cylinder body is installed with a piston, and with this cylinder body be separated into for hold gas one on the space with for the space once that holds fluid; Piston is movable in cylinder body axially between the two ends;
The bottom of this cylinder body is equipped with the oil duct that fuel feeding is circulated to down the space;
This piston is provided with this containing space of passage break-through;
The bottom of this piston is provided with a containing space;
Be provided with an one-way valve in this containing space and be sealed in this passage, and the last space of control gas can be from the passage earial drainage to following space.
The drive device for hydraulic of described a kind of elevation and subsidence mechanical also includes an elastic element in order to this one-way valve of pushing tow, and is provided with an annulus around this one-way valve, and this annulus provides a pore for air ventilation.
The drive device for hydraulic of described a kind of elevation and subsidence mechanical, wherein said elastic element are springs.
The drive device for hydraulic of described a kind of elevation and subsidence mechanical, wherein the top of this cylinder body is provided with one in order to seal this cylinder body and to wear fixed end caps for this piston rod.
The drive device for hydraulic of described a kind of elevation and subsidence mechanical, wherein this piston apical margin has a projection, and passage level on sidewall around this projection penetrates the centre to this piston, and break-through vertically downward is to the containing space of piston base again; When piston displacement in the cylinder end caps position, constitute the minimum volume that goes up the space around the projection and between end cap.
The drive device for hydraulic of described a kind of elevation and subsidence mechanical is characterized in that, wherein this passage is to extend axially also break-through to the containing space of piston base from piston rod; Piston rod in adjacent piston has radial hole communication passage and last space.
Description of drawings
Fig. 1 is the section plan of the present invention when no oil-feed;
Fig. 2 is the section plan of the present invention when the initial oil-feed;
Fig. 3 is the crosscut sectional drawing of piston head of the present invention;
Fig. 4 is the crosscut sectional drawing of piston base of the present invention;
Section plan when Fig. 5 is subjected to downforce for one-way valve of the present invention;
Fig. 6 is that the present invention is at F A=F BAnd P AP BThe time, the schematic representation when the valve plug desire is opened;
Fig. 7 has opened at valve plug for the present invention, and the schematic representation of top air when flowing into the space, below;
Fig. 8 is pushed the schematic representation that is extruded onto the cylinder body top for piston of the present invention;
Fig. 9 pushes back the schematic representation of piston rod by the weight of load for the present invention;
Figure 10 is second embodiment of single-lift cylinder body of the present invention;
Figure 11 is the section plan of known single-lift cylinder body.
Embodiment
See also Fig. 1 to Figure 10, be the selected example structure of the present invention shown in the figure, this only for the usefulness of explanation, is not subjected to the restriction of this kind structure in patent application.
Embodiment 1
As Fig. 1 and shown in Figure 2, embodiment for the drive device for hydraulic of elevation and subsidence mechanical of the present invention, it comprises a cylinder body 1 that is hollow, the top of this cylinder body 1, be spirally connected and be fixed with an end cap 11 in order to this cylinder body 1 top of deadend, and this end cap 11 runs through with fixing for a piston rod 2, and on the surface of contact of this end cap 11 and this piston rod 2, be equipped with in order to increase bubble-tight sealing gasket 111, on the surface of contact of this end cap 11 and this cylinder body 1 madial wall, also be equipped with one in order to increase bubble-tight 0 shape ring 112; Secondly, this cylinder body 1 bottom is equipped with one in sidewall on every side and makes this cylinder body 1 inner oil duct 12 that communicates with the external world, and this oil duct 12 lies in extraneous connecting part spiral shell and establishes a transport pipe 13.
Moreover, the two ends of above-mentioned this piston rod 2 are positioned at the inside and extraneous place of this cylinder body 1, and this piston rod 2 is connected with a piston 3 in an end of cylinder interior, and this cylinder body 1 is separated on one space 14 and space 15 once up and down, wherein air is to be sealed on this cylinder body within the space 14 in the mode that can't contact with the external world; And this piston rod 2 in the external world one outside rod end 21 be in order to bear a load 22; Secondly, these piston 3 apical margins have a projection 31, and a passage 32 level on sidewall around this projection 31 penetrates to the centre of this piston 3, again with vertically downward the mode break-through containing space 33 to piston 3 bottoms.
And be provided with an one-way valve 4 in order to the control air ventilation in this containing space 33, but and the spring 5 that makes progress of this one-way valve of pushing tow bottom; Wherein, the top of this one-way valve 4 is provided with one and can connects airtight and blockade the valve plug 41 of this passage 32, and be equipped with around this one-way valve 4 one with the contacted annulus 42 of sidewall around this containing space 33, these annulus 42 end faces are penetrated with a pore 421 for air ventilation to the bottom surface; In addition, above-mentioned these spring 5 bottoms more are equipped with one for its fixing clasp 51.
Extremely shown in Figure 9 as Fig. 2, in the present embodiment, when injecting an oil pressure P BHydraulic oil to following space 15, cause this piston 3 in this cylinder body 1 when up mobile, the space in space 14 can diminish thereupon this on, simultaneously, the air in this in the space 14, will this piston 3 as the motion as pushing under, produce an air pressure P A, and oil pressure P BWith air pressure P ACan form a pressure difference to each other, this pressure difference can be used as the driving force that this valve plug 41 of control opens and closes, as shown in Figure 5.
Because of this piston 3 is subjected to pushing of below oil-feed, and upward the space in space 14 reduces thereupon, can make the top and bottom of this piston 3 be subjected to one respectively vertically to the effect of strength, and it is respectively a downward F AWith the F that makes progress BAs shown in Figure 3, this strength F is born at these piston 3 tops as can be known AThe area A of effect is to be this cross section area A in piston 3 intermediate portions 1Cut this piston rod 2 cross section areas
Figure C200610056781D00081
Promptly As shown in Figure 4, this strength F is born in these piston 3 bottoms BThe area B of effect is this cross section area B in piston 3 bottoms 1Add this containing space 33 cross section area B 2, i.e. B=B 1+ B 2Hence one can see that, and this strength F is born in these piston 3 bottoms BThe area B of effect is born this strength F greater than its top AThe area A of effect, that is B〉A; Again because strength is the product for pressure and area, so F AWith F BCan be expressed as respectively: F A=P A* A and F B=P B* B.
In sum, as strength F BF AThe time, promptly this piston 3 is by F BPush when rising this air pressure P AForce value can increase gradually, at this air pressure P AContinued compression down by this piston 3, can produce one is enough to stop the strength F that this piston 3 moves up AWith force value, and suppose this strength F AIncrease to F A=F BThe time, because of the area magnitude relationship at these piston 3 bottoms and top is B〉A, so this one-way valve 4 affords this air pressure P up and down AWith oil pressure P BThe pass be P AP BState, at this moment, as this air pressure P AHave greater than this oil pressure P BDuring with the strength of these spring 5 elastic force, this one-way valve 4 will compress this spring 5 and be a state of opening, then, should go up in the space 14 and be able to be flowed in this time space 15 by this passage 32 of mat by the air of high compression, this moment, this time space 15 will have air and oil down respectively simultaneously thereon, and this moment, F will appear in this piston stressed again BF AState, finally this piston 3 can be pushed the top that rises to this cylinder body 1.
When this piston 3 displacements during in end cap 11 positions of this cylinder body 1, space 14 is only kept around the projection 31 of these piston 3 apical margins and the minimum volume of 11 formations of this end cap on this, so interior this air pressure P of this cylinder body 1 ABe an overvoltage condition; And in the deadweight of the weight of utilizing this load 22 to press down or piston rod 2, this piston rod 2 can need not to push back under the motivational drive this cylinder body 1 bottom; At this moment, in the process that this piston rod 2 inwardly pushes back, be placed in the overpressure air in the space on this 14, back pressure is final gradually, and when this piston 3 forced back towards this cylinder body 1 bottom, last space 14 interior air are negative pressure slightly.
Above-mentioned situation, the internal state that is presented during the initial start of an oil hydraulic cylinder for this reason, thereby when this piston 3 is pushed to this cylinder body 1 top first, much more the former air of going up in the space 14 is released into down space 15 by one-way valve 4, the final space of overpressure air around projection 31 of only depositing appropriateness, yet when piston 3 pushed back to this cylinder base, these overpressure air were replied maximum volume because of the volume in last space 14, so can present negative pressure; If when once more this piston 3 being pushed into cylinder body 1 top, the air in the last space 14 promptly changes overpressure air once again; In a word, the air storage in last space 14 can be a constant state in use in the present embodiment.
In sum, present embodiment is a relation of utilizing the pressure difference of interior air of this cylinder body and fluid as can be known, and this piston can be moved reciprocatingly in this cylinder body smoothly; Wherein, because of air used in the present invention is to be sealed in this cylinder interior, so from start to finish, air in this cylinder body all can't contact with the air in the external world, therefore will can not polluted, so can solve as this cylinder body in the known technology because of the contaminated situation that is damaged by the dust in the external world, aqueous vapor and corrosivity material.
According to the foregoing invention structure, suppose that these piston 3 top and bottoms bear respectively downwards and the strength F that makes progress CWith F D(not shown), and these piston 3 top and bottoms bear strength F CWith F DThe area of effect is respectively C and D (not shown), and the air at this piston place, space about in the of 3 and the pressure of oil are respectively P CWith P D(not shown), and according to the relation between strength, pressure and the area, can be with F CWith F DBe expressed as F C=P C* C and F D=P D* D.
And when this piston 3 is continued to push upwards by the below oil-feed, because of the opportunity that this valve plug 41 on this one-way valve 4 opens and closes, be to depend on P CWith P DPressure difference, when this piston 3 moves up, strength F CWith F DBe to be F DF CState, but by F C=P C* C and F D=P D* D two formulas can learn, as long as the area C and the D of these piston 3 upper and lowers done an adjustment, and can be at F DF CThe time, promptly when this piston 3 still rises, produce a P CP DPressure difference, at this moment, this one-way valve 4 is at this air pressure P CPushing under, will make this valve plug 41 be a state of opening, but and make the air water conservancy diversion of this superjacent air space go in this time side space.
The mechanism that opens and closes of this valve plug is as can be known controlled by existing pressure difference between air and the oil in sum, and promptly the strength of the top and bottom that this piston bore not is the key of this valve plug keying, is in F at aforementioned this valve plug for example A=F BIn time, open.
The above embodiment's announcement is in order to explanation the present invention, is not in order to restriction the present invention, so the displacement of the change of numerical value or equivalence element must be subordinate to category of the present invention such as.
Embodiment 2
As shown in figure 10 for another example of the present invention, wherein this passage 321 be from these piston 3 bars extend axially and break-through to this containing spaces 33 of this piston 3 bottoms, have a radial hole 322 in this piston rod 2 of adjacent piston and be communicated with this passage 321 and should go up space 14.
Be different from embodiment 1, when this piston 3 is moved to end cap 11 positions of this cylinder body 1, only be maintained at passage 321 volumes in this piston rod 2 for the savings air, so these passage 321 interior air pressures are to be an overvoltage condition; And when piston 3 pushed back to this cylinder body 1 bottom, the overpressure air in this passage 321 was back to the volume that reply in space 14, so can present negative pressure; That is, if once more when piston 3 is pushed into cylinder body 1 top, last space 14 interior air promptly flow to once again in the passage 321 and change overpressure air into.

Claims (5)

1. the drive device for hydraulic of an elevation and subsidence mechanical comprises a cylinder body and a piston rod, and the end of this piston rod in this cylinder body is installed with a piston, and with this cylinder body be separated into for hold gas one on the space with for the space once that holds fluid; Piston is also movable in cylinder body axially between the two ends;
The bottom of this cylinder body is equipped with the oil duct that fuel feeding is circulated to down the space;
The bottom of this piston is provided with a containing space;
This piston is provided with this containing space of passage break-through and should goes up the space, and this piston apical margin has a projection, when piston displacement during in the cylinder body top, will constitute the upward minimum volume in space around this projection and between the cylinder body top;
Be provided with an one-way valve in this containing space and be sealed in this passage, and the last space of control gas can be from the passage earial drainage to following space, and when this piston moves in the cylinder body top, gas pressure in the last space is to be overvoltage condition, and in piston moves to cylinder body during the bottom, the gas pressure in last space is to be negative pressure state.
2. the drive device for hydraulic of elevation and subsidence mechanical according to claim 1 is characterized in that, wherein an elastic element is in order to this one-way valve of pushing tow, and is provided with an annulus around this one-way valve, and this annulus system provides a pore for air ventilation.
3. the drive device for hydraulic of elevation and subsidence mechanical according to claim 1 is characterized in that, wherein this elastic element is a spring.
4. the drive device for hydraulic of elevation and subsidence mechanical according to claim 1 is characterized in that, wherein the top of this cylinder body is provided with one in order to seal this cylinder body and to wear fixed end caps for this piston rod.
5. the drive device for hydraulic of elevation and subsidence mechanical according to claim 4 is characterized in that, wherein this passage level on sidewall around this projection penetrates the centre to this piston, and break-through vertically downward is to the containing space of piston base again.
CNB2006100567811A 2006-03-08 2006-03-08 Oil-pressure driving device of lifting machine Expired - Fee Related CN100464080C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CNB2006100567811A CN100464080C (en) 2006-03-08 2006-03-08 Oil-pressure driving device of lifting machine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNB2006100567811A CN100464080C (en) 2006-03-08 2006-03-08 Oil-pressure driving device of lifting machine

Publications (2)

Publication Number Publication Date
CN101033761A CN101033761A (en) 2007-09-12
CN100464080C true CN100464080C (en) 2009-02-25

Family

ID=38730457

Family Applications (1)

Application Number Title Priority Date Filing Date
CNB2006100567811A Expired - Fee Related CN100464080C (en) 2006-03-08 2006-03-08 Oil-pressure driving device of lifting machine

Country Status (1)

Country Link
CN (1) CN100464080C (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2973454B1 (en) * 2011-03-31 2014-03-28 Messier Bugatti HYDRAULIC ACTUATOR WITH AUTOMATIC PURGE AT THE END OF THE RACE.
CN103290744B (en) * 2013-06-04 2015-02-18 王影 Quantitative intermittent oil injector for railway
CN103511389B (en) * 2013-10-15 2015-07-15 湖南特力液压有限公司 Singe-acting hydraulic cylinder
CN104564895B (en) * 2013-10-24 2017-02-15 比亚迪股份有限公司 Single-acting plunger cylinder and forklift
CN108105198A (en) * 2016-11-25 2018-06-01 湖北江山液压科技有限公司 A kind of single-action hydraulic cylinder

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06307411A (en) * 1993-04-19 1994-11-01 Toyo Electric Mfg Co Ltd Double acting cylinder
JPH09235096A (en) * 1996-03-01 1997-09-09 Toyota Autom Loom Works Ltd Lift cylinder on industrial vehicle
JPH10288265A (en) * 1997-04-15 1998-10-27 Tlv Co Ltd Spring energizing check valve
CN2653195Y (en) * 2003-08-15 2004-11-03 卫德义 Hydraulic mechanism with rigid locking of rebound and pull

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06307411A (en) * 1993-04-19 1994-11-01 Toyo Electric Mfg Co Ltd Double acting cylinder
JPH09235096A (en) * 1996-03-01 1997-09-09 Toyota Autom Loom Works Ltd Lift cylinder on industrial vehicle
JPH10288265A (en) * 1997-04-15 1998-10-27 Tlv Co Ltd Spring energizing check valve
CN2653195Y (en) * 2003-08-15 2004-11-03 卫德义 Hydraulic mechanism with rigid locking of rebound and pull

Also Published As

Publication number Publication date
CN101033761A (en) 2007-09-12

Similar Documents

Publication Publication Date Title
CN100464080C (en) Oil-pressure driving device of lifting machine
CN100376807C (en) Piston type energy accumulator
CN202501056U (en) Ventilation valve of pump oil tank
US20140311577A1 (en) Self replenishing accumulator
JP4490388B2 (en) Hydraulic drive for lifting equipment
CN207934873U (en) A kind of movable type gas lift liquid drainage reservoir protection speed column
CN108166955A (en) A kind of movable type gas lift liquid drainage reservoir protection speed column and method
CN203756112U (en) Well washing balance packer
CN2916217Y (en) Piston accumulator
CN201276866Y (en) Self-locking type elevation mast
CN212958547U (en) Well head protection device with independent anchoring structure
CN201738866U (en) Anti-pollution well-cleaning packer
CN212054595U (en) Negative pressure type oil-gas mixed pumping pump capable of being matched with blowout prevention oil drain device
CN2720104Y (en) Fully-closed hydraulic packer
CN208073449U (en) A kind of reservoir protection gas lift liquid drainage control device
CN220118425U (en) Hydraulic cylinder for hydraulic pile hammer
CN203051018U (en) Manual single plunger pump with unloading function
CN113530489A (en) Anti-pollution packer and anti-pollution well-washing and swabbing integrated pipe column
CN111155955A (en) Negative-pressure oil-gas mixed pumping pump capable of being matched with blowout-prevention oil drainer and method
CN201221513Y (en) Multifunctional gas-liquid pressurizing cylinder with gas and oil isolation, automatic exhaust and automatic oil compensating
CN205991048U (en) A kind of automobile hydraulic cylinder sealing device
CN2777184Y (en) External packer filling tool for completion pipe of horizontal well
CN2332704Y (en) Automotive double-cylinder hydraulic jack
CN205225167U (en) Packer
CN217629889U (en) Positioning device for overwater steel pipe pile construction platform

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20090225

CF01 Termination of patent right due to non-payment of annual fee