EP1378041A1 - A method and a device for removing ice and snow from a powerline - Google Patents

A method and a device for removing ice and snow from a powerline

Info

Publication number
EP1378041A1
EP1378041A1 EP02720735A EP02720735A EP1378041A1 EP 1378041 A1 EP1378041 A1 EP 1378041A1 EP 02720735 A EP02720735 A EP 02720735A EP 02720735 A EP02720735 A EP 02720735A EP 1378041 A1 EP1378041 A1 EP 1378041A1
Authority
EP
European Patent Office
Prior art keywords
cables
helicopter
lines
aircraft
result
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Withdrawn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
EP02720735A
Other languages
German (de)
French (fr)
Inventor
Lars Berglund
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 EP1378041A1 publication Critical patent/EP1378041A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
    • H02G7/00—Overhead installations of electric lines or cables
    • H02G7/16—Devices for removing snow or ice from lines or cables

Definitions

  • the present invention relates to a method for removing ice and snow from a power line construction of the kind defined in the preamble of the accompanying method Claim.
  • the invention also relates to a corresponding arrangement of the kind defined in the preamble of the accompanying apparatus Claim.
  • an object of the present invention is to provide a technique which enables snow and ice to be removed effectively from a power line construction with the aid of an aircraft.
  • a concrete example of the invention requires the use of a helicopter that flies along and above the power line construction, relatively close thereto.
  • the helicopter shall carry a generally horizontal support beam which extends transversely to the longitudinal direction of the helicopter.
  • Hanging from the support beam are long flexible cables that are spaced evenly along the beam at selected intervals.
  • the support beam and cables, or respective cable magazines, are preferably secured by detachable fasteners, for example screws, such that the position of the centre of gravity of the helicopter will not be changed to any appreciable extent.
  • the helicopter is intended to fly above the power lines at a height at which the cables will extend down between the lines and lie on respective sides thereof. Because the cables are flexible and are subjected to lateral oscillatory movement relative to the individual lines of the power line construction as the helicopter flies along said lines, the cables are able to act mechanically against the power lines such as to break-up the coatings of snow and ice, which is then able to fall down onto the ground below.
  • the cables swing partly in the direction in which the helicopter travels, due partly to the slipstream and the effect of the wind, and partly to the effect of the downwardly acting airstream from the main rotor of the helicopter.
  • the individual lines of the power line construction are thus subjected to a powerful airstream, primarily from the main rotor of the helicopter, and also to mechanical treatment from the cables, wherein the rotor airstream and other airstreams ensure that the cables will be swung laterally even when the helicopter flies along the power line construction.
  • the cables are provided with weakenings or fracture points that have a well-defined and limited breaking strength. This reduces the danger of a helicopter crashing as a result of a suspended cable-part fastening to a power line.
  • the helicopter and the cables may, of course, be steered to influence trees situated close to the power lane, if so desired.
  • the cables may be supported from the beam through the medium of a cable magazine that is designed to enable adjustments to be made to the length of cable hanging from the beam.
  • the cable magazine may be operable in a manner to enable an adjustment to be made to the length of the individual cable hanging from the beam.
  • the cable may be produced with a predetermined tensile strength that ensures that the tensile force in the cable prior to its fracture will lie beneath a predetermined value, with the intention of reducing the risk of the arrangement breaking-up should one or more cables fasten, or to prevent the helicopter from crashing as a result of one or more cables fastening in the power line construction or in a tree.
  • the support beam and the cable magazine are preferably positioned at a level above the support surface of the aircraft landing gear.
  • Fig. 1 illustrates a helicopter that carries a power line working arrangement.
  • Fig. 2 is a view taken on the line II-II in Fig. 1.
  • Fig. 3 is a sectioned view taken on the line III-III in Fig. 2.
  • Fig. 4 is a longitudinal sectioned view of a cable.
  • Figs. 1 and 2 illustrate a power line construction 1 situated in a power lane 2 that passes through woodland, e.g. a forest.
  • the power line construction 1 includes posts 11, which cany a number of overhead lines 12.
  • a helicopter 4 is shown to carry above its landing gear 5 a crossbeam 6, which extends generally horizontal and transversal to the longitudinal axis of the helicopter 4.
  • the crossbeam 6 carries a number of cable magazines 7 in mutually spaced relationship along the beam 6.
  • Each magazine 7 includes a flexible cable 8, which hangs down from its respective magazine.
  • the magazine 7 is adapted to enable the length of cable 8 hanging therefrom to be adjusted.
  • the helicopter may conveniently take-off and land with the cables 8 essentially fully drawn into their respective magazines 7.
  • the cable ends will preferably project out from respective magazines to some short extent, for instance through a distance of 0.5 m.
  • the magazines 7 are caused to feed out an appropriate length of respective cables 8. This enables the helicopter pilot to fly above and along the power line construction 1 and to fly the helicopter at a height at which cables 8 will hang down between and outwardly of respective overhead lines 12.
  • the lines 12 are subjected to a powerful, pulsating and downwardly acting airstream from the main rotor 41 of the helicopter, such as to free the lines 12 from snow, ice and water and possibly also to cause the lines 12 to swing.
  • the airstream from the main rotor 41 will, of course, also affect the cables 8 and cause said cables to swing.
  • the cables 8 will strike against the lines 12 as the helicopter flies along the power line construction 1, and will also slide against the cables so as to contribute to the removal of snow, ice and water from the lines 12, and also from the posts 11 and the means 13 by which the lines 12 are suspended from the posts 11.
  • the helicopter carries a device 90, which may have the form of a compressed air-cannon and/or an ultrasound cannot and/or a laser unit which, e.g., may be directed downwards so as to remove snow, ice and water from, e.g., the power lines when activated.
  • a device 90 which may have the form of a compressed air-cannon and/or an ultrasound cannot and/or a laser unit which, e.g., may be directed downwards so as to remove snow, ice and water from, e.g., the power lines when activated.
  • Fig. 3 illustrates the carrier beam 6 and the magazine 7 carrying the cable 8 in larger scale.
  • tire magazine 7 may include a cable drum 71 which is powered by a motor 72 for taking up and paying out the cable 8, wherein the motor may be remotely controlled, e.g., from the interior of the helicopter 4.
  • Each magazine 7 is preferably connected to the carrier beam via an explosive fuse which when activated (e.g. by remote control from the pilot, or automatically when its load exceeds a given value) separates the whole of the magazine from said carrier beam.
  • the cable 8 is given a predetermined breaking strength, so that it will be pulled off if the tensile force exceeds a chosen value.
  • the cable 8 may comprise a series of cable sections that are mutually connected via weakenings 82 or the like that define fracture points in respect of the cable 8.
  • the weakenings of fracture points 82 may be graded so as to provide an increasingly lower breaking limit towards the bottom end of the cable 8.
  • the cable 8 and its sections 81 will preferably be comprised of a non-conductive material.
  • the flexibility or suppleness of the cables 8 will preferably be chosen so that the cable 8 will have a low tendency to wrap itself around a line carrier 13, for instance.
  • the cables 8 may conveniently have a relatively high mass and may, for instance, be comprised of a hose that is filled with sand and closed to form a cable section 81, wherewith said closure may include a fracture means 82 in the form of a weakening in the hose-closing weld.

Abstract

A helicopter (4) carries a generally horizontal beam (6) that extends transversely to the longitudinal axis of the helicopter (4). The beam (6) carries along its length a plurality of mutually spaced magazines (7) for housing flexible cables (8) that can be fed-out to hang down from respective magazines (7) and taken back into said magazine. As the helicopter (4) flies along a power line construction (1), the cables hang down between and outside the power lines (12) of said construction (1), so as to work mechanically on the lines (12) such as to remove snow, ice and water therefrom, at same time as the airstream form the main rotor (41) of the helicopter (4) acts on the power line construction (1) and the cables (8).

Description

A method and a device for removing ice and snow from a powerline
The present invention relates to a method for removing ice and snow from a power line construction of the kind defined in the preamble of the accompanying method Claim.
The invention also relates to a corresponding arrangement of the kind defined in the preamble of the accompanying apparatus Claim.
Rain and snow will occasionally freeze onto the individual power lines of a power line construction in the winter months, and also on trees that border on the so-called power lane. Snow, ice and wind can cause trees to bend inwards over neighbouring power lines or collapse onto said lines. The weight of the snow and ice fastening to the lines may be of such magnitude as to cause a line to break, particularly under the influence of wind and the resonance effects occurring as the lines swing laterally.
It is know that the danger of such consequences can be reduced, by flying a helicopter along the power line construction in its close proximity, so that the airstream projected downwards from the main rotor of the propeller will function to break-up the snow and ice coatings and therewith loosen and dislodge the snow and ice from respective lines. The air flow from the helicopter rotor may, of course, also be directed onto trees in the proximity of the power lane, so as to reduce the risk of trees bending-in over the power line construction or falling onto the power lines under the weight of the snow and ice settling thereon .
The effect obtained with a helicopter is, however, limited, particularly when the snow and ice is frozen hard on the power lines and trees.
Accordingly, an object of the present invention is to provide a technique which enables snow and ice to be removed effectively from a power line construction with the aid of an aircraft.
This object is achieved by the present invention. The invention is defined in the accompanying independent method Claim.
The invention is also defined in the accompanying independent apparatus Claim.
Further embodiments of the invention will be apparent from the accompanying dependent method Claims.
A concrete example of the invention requires the use of a helicopter that flies along and above the power line construction, relatively close thereto. The helicopter shall carry a generally horizontal support beam which extends transversely to the longitudinal direction of the helicopter. Hanging from the support beam are long flexible cables that are spaced evenly along the beam at selected intervals. The support beam and cables, or respective cable magazines, are preferably secured by detachable fasteners, for example screws, such that the position of the centre of gravity of the helicopter will not be changed to any appreciable extent.
The helicopter is intended to fly above the power lines at a height at which the cables will extend down between the lines and lie on respective sides thereof. Because the cables are flexible and are subjected to lateral oscillatory movement relative to the individual lines of the power line construction as the helicopter flies along said lines, the cables are able to act mechanically against the power lines such as to break-up the coatings of snow and ice, which is then able to fall down onto the ground below.
The cables swing partly in the direction in which the helicopter travels, due partly to the slipstream and the effect of the wind, and partly to the effect of the downwardly acting airstream from the main rotor of the helicopter.
The individual lines of the power line construction are thus subjected to a powerful airstream, primarily from the main rotor of the helicopter, and also to mechanical treatment from the cables, wherein the rotor airstream and other airstreams ensure that the cables will be swung laterally even when the helicopter flies along the power line construction. The cables are provided with weakenings or fracture points that have a well-defined and limited breaking strength. This reduces the danger of a helicopter crashing as a result of a suspended cable-part fastening to a power line.
The helicopter and the cables may, of course, be steered to influence trees situated close to the power lane, if so desired.
The cables may be supported from the beam through the medium of a cable magazine that is designed to enable adjustments to be made to the length of cable hanging from the beam. The cable magazine may be operable in a manner to enable an adjustment to be made to the length of the individual cable hanging from the beam.
The cable may be produced with a predetermined tensile strength that ensures that the tensile force in the cable prior to its fracture will lie beneath a predetermined value, with the intention of reducing the risk of the arrangement breaking-up should one or more cables fasten, or to prevent the helicopter from crashing as a result of one or more cables fastening in the power line construction or in a tree.
The support beam and the cable magazine are preferably positioned at a level above the support surface of the aircraft landing gear.
The invention will now be described by way of example with reference to the accompanying drawings.
Fig. 1 illustrates a helicopter that carries a power line working arrangement.
Fig. 2 is a view taken on the line II-II in Fig. 1.
Fig. 3 is a sectioned view taken on the line III-III in Fig. 2.
Fig. 4 is a longitudinal sectioned view of a cable.
Figs. 1 and 2 illustrate a power line construction 1 situated in a power lane 2 that passes through woodland, e.g. a forest. The power line construction 1 includes posts 11, which cany a number of overhead lines 12. A helicopter 4 is shown to carry above its landing gear 5 a crossbeam 6, which extends generally horizontal and transversal to the longitudinal axis of the helicopter 4. The crossbeam 6 carries a number of cable magazines 7 in mutually spaced relationship along the beam 6. Each magazine 7 includes a flexible cable 8, which hangs down from its respective magazine. The magazine 7 is adapted to enable the length of cable 8 hanging therefrom to be adjusted.
The helicopter may conveniently take-off and land with the cables 8 essentially fully drawn into their respective magazines 7. When the cables are withdrawn, the cable ends will preferably project out from respective magazines to some short extent, for instance through a distance of 0.5 m. When the helicopter is airborne, the magazines 7 are caused to feed out an appropriate length of respective cables 8. This enables the helicopter pilot to fly above and along the power line construction 1 and to fly the helicopter at a height at which cables 8 will hang down between and outwardly of respective overhead lines 12.
The lines 12 are subjected to a powerful, pulsating and downwardly acting airstream from the main rotor 41 of the helicopter, such as to free the lines 12 from snow, ice and water and possibly also to cause the lines 12 to swing. The airstream from the main rotor 41 will, of course, also affect the cables 8 and cause said cables to swing. As the helicopter moves along the power line construction 1, the horizontal flight direction of the helicopter will often deviate from the direction of the power lines 12. Consequently, the cables 8 will strike against the lines 12 as the helicopter flies along the power line construction 1, and will also slide against the cables so as to contribute to the removal of snow, ice and water from the lines 12, and also from the posts 11 and the means 13 by which the lines 12 are suspended from the posts 11.
As illustrated, the helicopter carries a device 90, which may have the form of a compressed air-cannon and/or an ultrasound cannot and/or a laser unit which, e.g., may be directed downwards so as to remove snow, ice and water from, e.g., the power lines when activated.
If the trees 9 bordering on the power lane 2 are in danger of bending-in over the power line structure, the helicopter carrying said cable arrangement may, of course, also be flown along the lane 2 so as to knock ice, snow and water from the trees, in a con-esponding manner. Fig. 3 illustrates the carrier beam 6 and the magazine 7 carrying the cable 8 in larger scale. As shown, tire magazine 7 may include a cable drum 71 which is powered by a motor 72 for taking up and paying out the cable 8, wherein the motor may be remotely controlled, e.g., from the interior of the helicopter 4. Each magazine 7 is preferably connected to the carrier beam via an explosive fuse which when activated (e.g. by remote control from the pilot, or automatically when its load exceeds a given value) separates the whole of the magazine from said carrier beam.
The cable 8 is given a predetermined breaking strength, so that it will be pulled off if the tensile force exceeds a chosen value. For example, the cable 8 may comprise a series of cable sections that are mutually connected via weakenings 82 or the like that define fracture points in respect of the cable 8. The weakenings of fracture points 82 may be graded so as to provide an increasingly lower breaking limit towards the bottom end of the cable 8.
The cable 8 and its sections 81 will preferably be comprised of a non-conductive material. The flexibility or suppleness of the cables 8 will preferably be chosen so that the cable 8 will have a low tendency to wrap itself around a line carrier 13, for instance. The cables 8 may conveniently have a relatively high mass and may, for instance, be comprised of a hose that is filled with sand and closed to form a cable section 81, wherewith said closure may include a fracture means 82 in the form of a weakening in the hose-closing weld.

Claims

1. A method of freeing a power line construction (1) from snow, ice and water deposits, wherein an aircraft (4), preferably a helicopter, flies over and along the power line structure (1), characterised by causing the aircraft to carry a plurality of flexible cables (8) that hang down from the helicopter and that are mutually spaced in a horizontal direction; flying the aircraft along and above said power line construction (1) with said cables (8) hanging down between the individual lines (12) of said power line construction (1), such as to cause the cables (8) to come into contact with said lines (12) and therewith dislodge snow, ice and water thereon as a result of the cables being caused to swing relative to the helicopter as a result of forces of inertia occurring during flight, and/or as a result of the cables being caused to swing as a result of the downwardly acting turbulent airstream from the helicopter rotor, and/or by possible deviations in directions in the horizontal plane between the flight path of the helicopter and the direction of said power lines, and/or as a result of the lines (12) being caused to swing by the downwardly acting turbulent airstream from the helicopter rotor, and/or as result of the cables sliding along said power lines (12).
2. A method according to Claim 1, characterised by adjusting the extent to which the cables hang down from the aircraft.
3. A method according to Claim 1 or 2, characterised by causing the cables (8) to be separated from the aircraft through the medium of a safety device (82) which becomes operative when tlie tensile force in the cable (8) exceeds a predetermined value.
4. A method according to any one of Claims 1-3, characterised by equipping the aircraft with a compressed-air cannon and/or an ultrasound cannon and/or a laser unit directed towards said power lines (12) and activated to remove snow, ice or water therefrom.
5. An arrangement for removing ice, snow and water from a power line construction (1) with the aid of an aircraft (4), characterised by an elongated, generally horizontal carrier beam (6) which is carried by the aircraft (4) and, in turn, carries a plurality of flexible cables (8) which are mutually spaced along the beam (6), wherein the beam (6) is intended to extend transversely of the power line construction (1) so that the cables (8) will be able to hang down between the power lines (12) of said construction (1) and outside said lines, wherewith the cables (8) come into contact with the lines (12) and therewith remove snow, ice and water therefrom as a result of the cables swinging relative to the helicopter by virtue of inertia forces generated during flight, and/or as a result of the cables being caused to swing by virtue of the downwardly-acting turbulent airstream from the helicopter rotor, and/or as a result of possible deviations in directions in the horizontal plane between the flight path of the helicopter and the direction of the power lines, and/or as a result of the lines (12) being caused to swing by the downwardly-acting turbulent airstream from the helicopter rotor, and/or as a result of the cables sliding along the power lines (12).
6. An arrangement according to Claim 5, characterised in that the carrier beam (6) is mounted above a lower support surface for the landing gear of the aircraft (4); and in that a device (7) is provided above said support surface to enable the cables (8) to be taken-up and payed-out respectively.
7. An arrangement according to Claim 6, characterised in that said device includes a cable magazine (7) for each cable (8); and in that the cable magazine (7) can be remotely controlled for paying-out and taking-up an associated cable (8).
8. An arrangement according to any one of Claims 5-7, characterised in that an outer longitudinal section (81) of the cable (8) is carried via a safety device (82) which is activated at a predetermined tensile load.
9. An arrangement according to Claim 8, characterised in that the aircraft (4) is a helicopter.
10. An arrangement according to any one of Claims 5-9, characterised in that the aircraft carries a laser unit and or a compressed-air cannon and/or an ultrasound generator for contactless action on snow, ice or water deposits on power line constructions (1).
EP02720735A 2001-04-11 2002-04-11 A method and a device for removing ice and snow from a powerline Withdrawn EP1378041A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
SE0101292 2001-04-11
SE0101292A SE518439C2 (en) 2001-04-11 2001-04-11 Method and apparatus for removing ice and snow from a power line
PCT/SE2002/000716 WO2002084834A1 (en) 2001-04-11 2002-04-11 A method and a device for removing ice and snow from a powerline

Publications (1)

Publication Number Publication Date
EP1378041A1 true EP1378041A1 (en) 2004-01-07

Family

ID=20283757

Family Applications (1)

Application Number Title Priority Date Filing Date
EP02720735A Withdrawn EP1378041A1 (en) 2001-04-11 2002-04-11 A method and a device for removing ice and snow from a powerline

Country Status (4)

Country Link
EP (1) EP1378041A1 (en)
NO (1) NO20034494D0 (en)
SE (1) SE518439C2 (en)
WO (1) WO2002084834A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106877238A (en) * 2017-03-18 2017-06-20 淄博萃智工业设计咨询有限公司 A kind of power circuit Bird's Nest sweep-out method
CN110729691A (en) * 2019-11-07 2020-01-24 重庆大学 Hot water deicing system and method for insulator in ultrahigh voltage transmission line
CN110838701A (en) * 2019-11-08 2020-02-25 南京聚联输变电安装有限责任公司 Intelligent deicing device for power transmission and transformation line

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102611063B (en) * 2012-01-13 2014-10-08 华北电力大学 Ultrasonic deicing device for high-voltage power transmission lines and deicing method of ultrasonic deicing device
FI124261B (en) 2012-09-20 2014-05-30 Global Boiler Works Oy A method and apparatus for removing material from a transmission line
CN105932629B (en) * 2014-05-16 2018-02-16 侯荣华 A kind of deicing of high-voltage wires avenges system
US9993852B2 (en) 2014-08-20 2018-06-12 Elwha Llc Surface cleaning unmanned aerial vehicle
CN105305355A (en) * 2015-11-22 2016-02-03 无锡同春新能源科技有限公司 De-icing unmanned machine equipped with thermal radiation device
CN106099816B (en) * 2016-06-23 2017-10-31 绍兴意诺贸易有限公司 A kind of suspension type trolley wire electrical cable intelligent deicing robot
CN106025981B (en) * 2016-06-23 2017-10-24 绍兴俪泰纺织科技有限公司 A kind of electric power transmission line deicing aircraft
CN106025983B (en) * 2016-06-23 2017-10-31 绍兴意诺贸易有限公司 A kind of trolley wire cable deicing unmanned plane
CN108334113A (en) * 2018-04-19 2018-07-27 北京邮电大学 Unmanned plane deicing system and method
CN108390313A (en) * 2018-04-28 2018-08-10 广东电网有限责任公司 A kind of overhead transmission line, which floats, hangs object cleaning plant
CN108448522B (en) * 2018-04-29 2019-03-29 张景熙 A kind of high altitude operation cable deicing unmanned plane
CN109167321B (en) * 2018-10-24 2020-01-10 中国石油大学(华东) Deicing unmanned aerial vehicle
CN111092403B (en) * 2020-02-16 2020-12-15 台州市阿里菜鸟电子商务有限公司 Aerial working cable deicing unmanned aerial vehicle
CN111545502A (en) * 2020-04-23 2020-08-18 曹树梁 Dust removing device for desert sunlight absorption surface unmanned helicopter
CN114498518B (en) * 2022-01-28 2023-05-26 国网河南省电力公司洛阳供电公司 Ice coating removal method for power transmission and distribution line
CN116345381B (en) * 2023-05-24 2023-09-05 国网山西省电力公司晋城供电公司 Rope wave resonance deicing device for icing of overhead transmission line

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3916732A (en) * 1974-12-11 1975-11-04 Russell E Caldwell Ice removing tool
US4478312A (en) * 1982-09-30 1984-10-23 Kurtgis Michael P System and portable cage for servicing power transmission lines
US4637575A (en) * 1984-10-04 1987-01-20 Yenzer Scott H Helicopter airmobile work platform for working on power lines and tower structures
NZ247629A (en) * 1992-05-15 1995-12-21 Michael Paul Kurtgis Substitut Transferring a suspended bosun chair from a helicopter to a transmission line with load detachment requiring operation of two distinct release mechanisms
US5494132A (en) * 1994-02-14 1996-02-27 Hansen; Harry L. Side-loading suspension frame and ladder assembly for maintenance of energized power transmission lines

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO02084834A1 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106877238A (en) * 2017-03-18 2017-06-20 淄博萃智工业设计咨询有限公司 A kind of power circuit Bird's Nest sweep-out method
CN110729691A (en) * 2019-11-07 2020-01-24 重庆大学 Hot water deicing system and method for insulator in ultrahigh voltage transmission line
CN110838701A (en) * 2019-11-08 2020-02-25 南京聚联输变电安装有限责任公司 Intelligent deicing device for power transmission and transformation line
CN110838701B (en) * 2019-11-08 2020-09-11 南京聚联输变电安装有限责任公司 Intelligent deicing device for power transmission and transformation line

Also Published As

Publication number Publication date
NO20034494L (en) 2003-10-08
NO20034494D0 (en) 2003-10-08
SE0101292L (en) 2002-10-08
SE0101292D0 (en) 2001-04-11
WO2002084834A1 (en) 2002-10-24
SE518439C2 (en) 2002-10-08

Similar Documents

Publication Publication Date Title
EP1378041A1 (en) A method and a device for removing ice and snow from a powerline
EP2186728B1 (en) Unmanned air vehicle recovery system
EP3268277B1 (en) Uav capture system
EP1233905B1 (en) Launch and recovery system for unmanned aerial vehicles
US4753400A (en) Shipboard air vehicle retrieval apparatus
US9527604B2 (en) Unmanned air vehicle recovery system
AU2013261044B2 (en) Point take-off and landing of unmanned flying objects
US20090308979A1 (en) Parachute Release Device and Methods
US4554781A (en) Airborne tree trimmer
KR100243953B1 (en) Mooring tower assembly for a lighter-than-air vehicle
CN101988813A (en) Launching system and launching apparatus
JPH05503674A (en) Method and apparatus for supplying a fluid medium onto a workpiece selection area
DE3228557A1 (en) WARNING DEVICE FOR HELICOPTER
JP7055278B2 (en) Ice and snow removal device
WO2019053241A1 (en) Method for fighting fires in high-rise buildings and fire-extinguishing device
RU2592963C2 (en) Method for parachute landing of drone and drone with electric propulsor and parachute landing system
CN104104048B (en) Ice removal
RU2678407C1 (en) Airplane type unmanned aerial vehicle landing system
JPH06276634A (en) Wire extension method for stringing messenger wire of aerial wire and device thereof
RU2591115C1 (en) Non-aerodrome aircraft complex
JP6944905B2 (en) Spray equipment
KR100505412B1 (en) Radio control miniature aircraft
CN102891463A (en) Method for deicing by using power circuit deicing device
RU2775656C1 (en) Automated precision cargo delivery system by air
EP3540887A1 (en) Marker for power line cables or similar and method for installing said marker

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: 20030925

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Extension state: AL LT LV MK RO SI

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20091103