WO1988008939A1 - Device for operation in pipelines - Google Patents

Device for operation in pipelines Download PDF

Info

Publication number
WO1988008939A1
WO1988008939A1 PCT/SE1988/000244 SE8800244W WO8808939A1 WO 1988008939 A1 WO1988008939 A1 WO 1988008939A1 SE 8800244 W SE8800244 W SE 8800244W WO 8808939 A1 WO8808939 A1 WO 8808939A1
Authority
WO
WIPO (PCT)
Prior art keywords
caterpillar vehicle
drive
vehicle
wheels
upper member
Prior art date
Application number
PCT/SE1988/000244
Other languages
French (fr)
Inventor
Ulf LÖFGREN
Original Assignee
Loefgren Ulf
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 Loefgren Ulf filed Critical Loefgren Ulf
Publication of WO1988008939A1 publication Critical patent/WO1988008939A1/en
Priority to NO89890123A priority Critical patent/NO890123L/en

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E03—WATER SUPPLY; SEWERAGE
    • E03F—SEWERS; CESSPOOLS
    • E03F7/00—Other installations or implements for operating sewer systems, e.g. for preventing or indicating stoppage; Emptying cesspools
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B9/00—Cleaning hollow articles by methods or apparatus specially adapted thereto 
    • B08B9/02—Cleaning pipes or tubes or systems of pipes or tubes
    • B08B9/027—Cleaning the internal surfaces; Removal of blockages
    • B08B9/032—Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing
    • B08B9/035—Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing by suction
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B9/00—Cleaning hollow articles by methods or apparatus specially adapted thereto 
    • B08B9/02—Cleaning pipes or tubes or systems of pipes or tubes
    • B08B9/027—Cleaning the internal surfaces; Removal of blockages
    • B08B9/04—Cleaning the internal surfaces; Removal of blockages using cleaning devices introduced into and moved along the pipes
    • B08B9/049—Cleaning the internal surfaces; Removal of blockages using cleaning devices introduced into and moved along the pipes having self-contained propelling means for moving the cleaning devices along the pipes, i.e. self-propelled
    • E—FIXED CONSTRUCTIONS
    • E03—WATER SUPPLY; SEWERAGE
    • E03F—SEWERS; CESSPOOLS
    • E03F3/00—Sewer pipe-line systems

Definitions

  • This invention relates to a device for operation in pipelines, especially sludge exhaustion of sewers, said device comprising a remote-controlled self-acting caterpillar vehicle, the drive and tension wheels supporting the drive belt of the caterpillar vehicle being vertically adjustable relative to the caterpillar vehicle and pivotably arranged in a vertical plane perpendicular to the direction of travel of the caterpillar vehicle.
  • SE-lay-open print 443 522 teaches a self-acting device for disposal of viscous impurities accumulated in tanks for petroleum products, said device having certain basic similarities to the device according to the invention. However, there are also certain extraordinarily important constructive differences thanks to which the device of the invention has an improved function as compared with the known self-acting device.
  • Fig. 1 is a schematic lateral view of a caterpillar vehicle according to the invention introduced into a pipeline
  • Fig. 2 is a front view of the caterpillar vehicle according to Fig. 1
  • Fig. 3 is a front view of the caterpillar vehicle when this is introduced into a pipeline with twice as large a diameter as the pipeline shown in Figs. 1 and 2
  • Fig. 4 shows schematically the caterpillar vehicle in connection with sludge exhaustion of a pipeline.
  • Figs. 1 and 2 show a caterpillar vehicle 1 when this is introduced into a sewer 2 or the like.
  • the caterpillar vehicle 1 comprises an upper member 3 supported by a lower member in the form of two longitudinal frame members 4 via e.g. a lifting means 5 actuated by a pressure medium and arranged in each end of the respective frame member 4.
  • the lifting means 5, for example in the form of hydraulic cylinders, are arranged to enable a stepless adjustment of the distance between the upper member 3 and the frame members 4.
  • a number of for example hydraulic control and absorbing means 6, preferably two in each end of the respective frame member 4 in the region of the lifting means 5, are arranged between the upper member 3 and the frame member 4.
  • the control and absorbing means 6 ensure a rectilinear motion of the frame member 4 relative to the upper member 3 without the risk of wobbling.
  • Two drive wheels 7 independent of one another are arranged to enable motion of the vehicle 1 in a desired direction.
  • Each drive wheel 7 is operated by for example a hydraulic motor 8 arranged in one end of the frame member 4 and transmits motion to a preferably flexible drive belt 9 running about the drive wheel 8 and a tension wheel 10 arranged at the other end of the frame member 4.
  • the tension wheel 10 is preferably freely rotatably mounted in the frame member 4.
  • the drive wheel 7 and the tension wheel 10 are pivotable relative to the frame member 4 in a vertical plane perpendicular to the longitudinal axis of the vehicle 1 for adaptation to different pipeline diameters.
  • the angle of inclination of the drive and tension wheels 7 and 10 is steplessly adjustable by means of the hydraulic motor 8 in a suitable way not shown.
  • a suction hose 12 inserted into the fastening means 11 is shown.
  • the suction hose 12 can preferably be connected with the fastening means 11 by the aid of adjustable clamp means (not shown) extending around the suction hose 12. It is shown in Fig. 1 how the suction hose 12 extends along the whole caterpillar vehicle 1 and some distance in front of this and in such a way that the suction hose 12 wi l l be in contact with the bottom of the pipeline 2.
  • the vehicle 1 can be provided with other types of tools or instruments than a suction hose.
  • the vehicle 1 can be provided with for example root cutting tools, cement mortar isolating tools, welding equipment etc.
  • the upper member 3 On its upper side the upper member 3 is provided with for example a hydraulically operated video camera 13 which is rotatable in the horizontal plane around the whole periphery and in the vertical plane about 200°.
  • a hydraulically operated video camera 13 which is rotatable in the horizontal plane around the whole periphery and in the vertical plane about 200°.
  • the upper member 3 comprises a lifting and towing eyelet 14 i.a. to enable lowering and receiving of the caterpillar vehicle in a pipeline.
  • Fig. 3 shows how the vehicle 1 is introduced into a pipeline 2' of twice as large a diameter as the pipeline 2 shown in Figs. 1 and 2. As is apparent from Fig. 3 the distance between the upper and lower members 3 and 4 is greater while the angle of inclination of the wheels 7 and 10 is less than the adjusting position of the caterpillar vehicle shown in Figs. 1 and 2.
  • the vehicle 1 is shown in connection with sludge exhaustion of a pipeline 2.
  • the caterpillar vehicle 1 is lowered down into a pipeline 2 via a well 15 connecting to the pipeline 2.
  • a hydraulic hose 16 comprising a plurality of separate hydraulic lines for driving and operating the vehicle 1
  • the caterpillar vehicle 1 is connected with a hydraulic pressure source in the form of the hydraulic system 21 of a truck 17.
  • the suction hose 12 is connected with a sludge and suction tank 22 contained in the truck 17. Sludge is brought up by the aid of a strongly dimensioned suction pump, for example a vacuum pump (not shown), arranged in connection with the sludge and suction tank 22.
  • the hydraulic hose 16 and the suction hose 12 preferably extend alongside each other with the hydraulic hose 16 placed on top of the suction hose 12 and for this purpose they are combined by the aid of detachable fastening means 18 placed along the hoses at regular intervals.
  • simple carriages can be attached at a suitable distance from one another along the underside of the suction hose 12, the frictional resistance being reduced and the propulsion of the caterpillar vehicle 1 facilitated (not shown).
  • the vehicle 1 is remote controlled by an operator above ground level via an operating means 19 connected by way of hydraulic lines enclosed in the hydraulic hose 16 with a control unit of the vehicle 1 not shown.
  • a control unit comprises the necessary control valves for controlling the hydraulic motors 8, the lifting means 5, the control and absorbing means 6 and the video camera 13 which, further, are connected via hydraulic lines with the hydraulic pressure source 21.
  • the caterpillar vehicle 1 can be operated via the operating means 19 in a desired direction and at an optional speed.
  • the angle of inclination of the drive and tension wheels 7 and 10 can also be adjusted via the operating means 19 for the current pipeline dimension.
  • the position of the suction hose 12 can be adjusted via the operating means 19 by the aid of the lifting means 5 at the desired level above the bottom of the pipeline.
  • the caterpillar vehicle is driven and controlled hydraulically.
  • the drive and control of the caterpillar vehicle of course also can be carried out for example pneumatically and electrically, the choice of current components such as the motors 8, the adjusting means 5 and the control and absorbing means 6 of course being adapted to a desired drive source.
  • the caterpillar vehicle 1 is provided with a radio unit 20 as is most apparent from Figs. 1 and 2.
  • inventive caterpillar vehicle 1 is adaptable to work in pipelines of varying dimensions simultaneously as the inventive location of the fastening means 11 enables that the position of the tool 12 relative to the pipeline 2 can be steplessly adjusted so that the tool can always be brought into the desired position relative to the pipeline.

Abstract

The invention relates to a device for operation in pipelines (2), especially sludge exhaustion of sewers, said device comprising a remote-controlled, self-acting caterpillar vehicle (1). The drive (7) and tension wheels (10) supporting the drive belt (9) of the caterpillar vehicle (1) are vertically adjustable relative to the caterpillar vehicle (1) and pivotably arranged in a vertical plane perpendicular to the direction of travel of the caterpillar vehicle (1). The caterpillar vehicle (1) comprises an upper member (3) provided on its underside with a means (11) for fastening a tool in the form of for example a suction line (12). Means (5) are arranged for stepless adjustment of the distance between the upper member (3) and frame members (4) supporting the drive (7) and tension wheels (10). Furthermore, the caterpillar vehicle (1) comprises means (6) for control and absorption of the relative motion between the upper member (3) and the frame members (4). The frame members (4) comprise motors (8) for driving the drive wheels (7) and swinging the drive wheels (7) and the tension wheels (10). The means of adjustment (5) are for example hydraulically operated. The caterpillar vehicle (1) is adaptable to work in pipelines of varying dimensions simultaneously as the location of the fastening means (11) enables that the position of the tool (12) relative to the pipeline (2) can be adjusted steplessly.

Description

Device for operation in pipelines This invention relates to a device for operation in pipelines, especially sludge exhaustion of sewers, said device comprising a remote-controlled self-acting caterpillar vehicle, the drive and tension wheels supporting the drive belt of the caterpillar vehicle being vertically adjustable relative to the caterpillar vehicle and pivotably arranged in a vertical plane perpendicular to the direction of travel of the caterpillar vehicle.
SE-lay-open print 443 522 teaches a self-acting device for disposal of viscous impurities accumulated in tanks for petroleum products, said device having certain basic similarities to the device according to the invention. However, there are also certain extraordinarily important constructive differences thanks to which the device of the invention has an improved function as compared with the known self-acting device.
It is the object of this invention to provide an improved device of the kind indicated above, and this object is achieved in that the device has been given the features defined in the claims.
An illustrative example of the invention will be described below with reference to the enclosed drawings, wherein Fig. 1 is a schematic lateral view of a caterpillar vehicle according to the invention introduced into a pipeline, Fig. 2 is a front view of the caterpillar vehicle according to Fig. 1, Fig. 3 is a front view of the caterpillar vehicle when this is introduced into a pipeline with twice as large a diameter as the pipeline shown in Figs. 1 and 2, and Fig. 4 shows schematically the caterpillar vehicle in connection with sludge exhaustion of a pipeline.
Figs. 1 and 2 show a caterpillar vehicle 1 when this is introduced into a sewer 2 or the like. The caterpillar vehicle 1 comprises an upper member 3 supported by a lower member in the form of two longitudinal frame members 4 via e.g. a lifting means 5 actuated by a pressure medium and arranged in each end of the respective frame member 4. The lifting means 5, for example in the form of hydraulic cylinders, are arranged to enable a stepless adjustment of the distance between the upper member 3 and the frame members 4. Moreover, a number of for example hydraulic control and absorbing means 6, preferably two in each end of the respective frame member 4 in the region of the lifting means 5, are arranged between the upper member 3 and the frame member 4. The control and absorbing means 6 ensure a rectilinear motion of the frame member 4 relative to the upper member 3 without the risk of wobbling.
Two drive wheels 7 independent of one another are arranged to enable motion of the vehicle 1 in a desired direction. Each drive wheel 7 is operated by for example a hydraulic motor 8 arranged in one end of the frame member 4 and transmits motion to a preferably flexible drive belt 9 running about the drive wheel 8 and a tension wheel 10 arranged at the other end of the frame member 4. The tension wheel 10 is preferably freely rotatably mounted in the frame member 4. The drive wheel 7 and the tension wheel 10 are pivotable relative to the frame member 4 in a vertical plane perpendicular to the longitudinal axis of the vehicle 1 for adaptation to different pipeline diameters. The angle of inclination of the drive and tension wheels 7 and 10 is steplessly adjustable by means of the hydraulic motor 8 in a suitable way not shown. However, it is also possible to achieve a desired angle of inclination and thereafter to lock the wheels 7 and 10 in this angle of inclination by the aid of mechanical means. The underside of the upper member 3 is provided with an elongate means 11 for fastening different kinds of tools. In Figs. 1 and 2 a suction hose 12 inserted into the fastening means 11 is shown. The suction hose 12 can preferably be connected with the fastening means 11 by the aid of adjustable clamp means (not shown) extending around the suction hose 12. It is shown in Fig. 1 how the suction hose 12 extends along the whole caterpillar vehicle 1 and some distance in front of this and in such a way that the suction hose 12 wi l l be in contact with the bottom of the pipeline 2.
It is possible to provide the vehicle 1 with other types of tools or instruments than a suction hose. Thus, the vehicle 1 can be provided with for example root cutting tools, cement mortar isolating tools, welding equipment etc.
On its upper side the upper member 3 is provided with for example a hydraulically operated video camera 13 which is rotatable in the horizontal plane around the whole periphery and in the vertical plane about 200°.
In its front end the upper member 3 comprises a lifting and towing eyelet 14 i.a. to enable lowering and receiving of the caterpillar vehicle in a pipeline. Fig. 3 shows how the vehicle 1 is introduced into a pipeline 2' of twice as large a diameter as the pipeline 2 shown in Figs. 1 and 2. As is apparent from Fig. 3 the distance between the upper and lower members 3 and 4 is greater while the angle of inclination of the wheels 7 and 10 is less than the adjusting position of the caterpillar vehicle shown in Figs. 1 and 2.
In fig. 4 the vehicle 1 is shown in connection with sludge exhaustion of a pipeline 2. The caterpillar vehicle 1 is lowered down into a pipeline 2 via a well 15 connecting to the pipeline 2. Via a hydraulic hose 16 comprising a plurality of separate hydraulic lines for driving and operating the vehicle 1 the caterpillar vehicle 1 is connected with a hydraulic pressure source in the form of the hydraulic system 21 of a truck 17. Moreover, the suction hose 12 is connected with a sludge and suction tank 22 contained in the truck 17. Sludge is brought up by the aid of a strongly dimensioned suction pump, for example a vacuum pump (not shown), arranged in connection with the sludge and suction tank 22. The hydraulic hose 16 and the suction hose 12 preferably extend alongside each other with the hydraulic hose 16 placed on top of the suction hose 12 and for this purpose they are combined by the aid of detachable fastening means 18 placed along the hoses at regular intervals. In the case when long pipe systems are to be covered simple carriages can be attached at a suitable distance from one another along the underside of the suction hose 12, the frictional resistance being reduced and the propulsion of the caterpillar vehicle 1 facilitated (not shown).
The vehicle 1 is remote controlled by an operator above ground level via an operating means 19 connected by way of hydraulic lines enclosed in the hydraulic hose 16 with a control unit of the vehicle 1 not shown. Such a control unit comprises the necessary control valves for controlling the hydraulic motors 8, the lifting means 5, the control and absorbing means 6 and the video camera 13 which, further, are connected via hydraulic lines with the hydraulic pressure source 21. The caterpillar vehicle 1 can be operated via the operating means 19 in a desired direction and at an optional speed. The angle of inclination of the drive and tension wheels 7 and 10 can also be adjusted via the operating means 19 for the current pipeline dimension. If desired, for example if there are obstacles difficult to manage in the sewer, the position of the suction hose 12 can be adjusted via the operating means 19 by the aid of the lifting means 5 at the desired level above the bottom of the pipeline. In the illustrative example shown the caterpillar vehicle is driven and controlled hydraulically. However, it will be appreciated that the drive and control of the caterpillar vehicle of course also can be carried out for example pneumatically and electrically, the choice of current components such as the motors 8, the adjusting means 5 and the control and absorbing means 6 of course being adapted to a desired drive source.
Of course remote control in the form of radio control of the caterpillar vehicle is also possible, and for this purpose the caterpillar vehicle 1 is provided with a radio unit 20 as is most apparent from Figs. 1 and 2.
Thus, it will be appreciated that the inventive caterpillar vehicle 1 is adaptable to work in pipelines of varying dimensions simultaneously as the inventive location of the fastening means 11 enables that the position of the tool 12 relative to the pipeline 2 can be steplessly adjusted so that the tool can always be brought into the desired position relative to the pipeline.
The invention is not restricted to what has been shown and described, but amendments and modifications thereof are possible within the scope of the following claims.

Claims

Claims
1. Device for operation in pipelines, especially sludge exhaustion of sewers, said device comprising a remotely controlled self-acting caterpillar vehicle (1), the drive (7) and tension wheels (10) supporting the drive belt (9) of the caterpillar vehicle (1) being vertically adjustable relative to the caterpillar vehicle (1) and pivotably arranged in a vertical plane perpendicular to the direction of travel of the caterpillar vehicle (1), c h a r a c t e r i z e d in that the caterpillar vehicle (1) comprises an upper member (3) provided on its underside with a means (11) for fastening a tool, for example a suction line (12), and that means (5) are arranged for adjusting steplessly the distance between the upper member (3) and frame members (4) supporting the drive (7) and tension wheels (10).
2. The device of claim 1, c h a r a c t e r i z e d in that it comprises means (6) for control and absorption of the relative motion between the upper member (3) and the frame members (4).
3. The device of claim 1 or 2, c h a r a c t e r i z e d in that the frame members (4) comprise motors (8) for driving the drive wheels (7) and swinging the drive wheels (7) and the tension wheels CIO).
4. The device of any one of claims 1-3, c h a r a c t e r i z e d in that the adjusting means (5) are hydraulically operated.
5. The device of any one of claims 1-4, c h a r a c t e r i z e d in that the caterpillar vehicle (1) is provided with a camera unit (13) and a radio unit (20).
PCT/SE1988/000244 1987-05-12 1988-05-11 Device for operation in pipelines WO1988008939A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
NO89890123A NO890123L (en) 1987-05-12 1989-01-11 DEVICE FOR USE OF PIPE PIPES.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8701941A SE457652B (en) 1987-05-12 1987-05-12 DEVICE FOR CLEANING OF PIPES, SPECIFIC SLUDGE OF WASTE PIPES
SE8701941-0 1987-05-12

Publications (1)

Publication Number Publication Date
WO1988008939A1 true WO1988008939A1 (en) 1988-11-17

Family

ID=20368484

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1988/000244 WO1988008939A1 (en) 1987-05-12 1988-05-11 Device for operation in pipelines

Country Status (2)

Country Link
SE (1) SE457652B (en)
WO (1) WO1988008939A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0486379A1 (en) * 1990-11-12 1992-05-20 SA SACAVI (Société d'Achat, vente construction pour l'assainissement la voirie l'industrie) Material transporting apparatus, engine provided with such system and method for cleaning ducts
EP0607611A1 (en) * 1992-12-28 1994-07-27 Tokyo Gas Co., Ltd. Intrapipe work robot apparatus and method of measuring position of intrapipe work robot
EP0625078A1 (en) * 1992-02-03 1994-11-23 ALLEN, Henry, W. Remote controlled sludge removal apparatus

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3247922A (en) * 1964-07-13 1966-04-26 Hanson Co R A Support apparatus for surfacing equipment
US3872940A (en) * 1971-05-13 1975-03-25 Snam Progetti Self propelled self-adjusting carriage able to move along curved profiles as pipelines
DE2514023A1 (en) * 1975-03-29 1976-10-07 Hans Dr Ing Kohlmann Deposit remover for sewer channels - has high speed rotating wheels driven by motors mounted on frame
EP0052272A1 (en) * 1980-11-13 1982-05-26 Salzgitter Maschinen und Anlagen Aktiengesellschaft Winch for a sewer cleaning apparatus
SE443522B (en) * 1983-01-13 1986-03-03 Olofsson Bengt Arne Apparatus for the removal from tanks of coagulated, viscous impurities in petroleum products

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3247922A (en) * 1964-07-13 1966-04-26 Hanson Co R A Support apparatus for surfacing equipment
US3872940A (en) * 1971-05-13 1975-03-25 Snam Progetti Self propelled self-adjusting carriage able to move along curved profiles as pipelines
DE2514023A1 (en) * 1975-03-29 1976-10-07 Hans Dr Ing Kohlmann Deposit remover for sewer channels - has high speed rotating wheels driven by motors mounted on frame
EP0052272A1 (en) * 1980-11-13 1982-05-26 Salzgitter Maschinen und Anlagen Aktiengesellschaft Winch for a sewer cleaning apparatus
SE443522B (en) * 1983-01-13 1986-03-03 Olofsson Bengt Arne Apparatus for the removal from tanks of coagulated, viscous impurities in petroleum products

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0486379A1 (en) * 1990-11-12 1992-05-20 SA SACAVI (Société d'Achat, vente construction pour l'assainissement la voirie l'industrie) Material transporting apparatus, engine provided with such system and method for cleaning ducts
EP0625078A1 (en) * 1992-02-03 1994-11-23 ALLEN, Henry, W. Remote controlled sludge removal apparatus
EP0625078A4 (en) * 1992-02-03 1995-01-18 Henry W Allen Remote controlled sludge removal apparatus.
EP0607611A1 (en) * 1992-12-28 1994-07-27 Tokyo Gas Co., Ltd. Intrapipe work robot apparatus and method of measuring position of intrapipe work robot

Also Published As

Publication number Publication date
SE457652B (en) 1989-01-16
SE8701941L (en) 1988-11-13
SE8701941D0 (en) 1987-05-12

Similar Documents

Publication Publication Date Title
US5363925A (en) Mobile drilling machine
US5215071A (en) Riding pavement saw
US20050117973A1 (en) Method and system for preparing a trench and laying pipe in a trench
US8167053B2 (en) Powered mobile module and attachment combination
US6588976B2 (en) Concrete placing and screeding apparatus and method
US6623208B2 (en) Concrete placing and screeding apparatus and method
US7261493B2 (en) Device and method for laying and joining pipe
US10278331B2 (en) Method of forward mounting attachments to a wheeled vehicle
US3694033A (en) Roadway paint stripe grooving machine
US20120090498A1 (en) Pipe travelling apparatus with alignment control
US10219433B2 (en) System for forward mounting attachments to a wheeled vehicle
US20020015618A1 (en) Concrete placing machine with hydraulic and concrete swivel
US3490548A (en) Adjustably positioned vehicle mounted tool and tool support structure
WO1988008939A1 (en) Device for operation in pipelines
US6736219B1 (en) Underground horizontal boring apparatus
WO1988002435A1 (en) Boring apparatus
US4685832A (en) Underground pipe and cable laying machine
US4116014A (en) Excavating and pipeline installation system
US6176551B1 (en) Surface preparation apparatus and method of using the same
US3390533A (en) Machine for laying cable and the like
US3688510A (en) Submarine rock placing traveler
US6315500B1 (en) Ground watering spray system for backhoe machines
US5388654A (en) Ground-boring device
US3815689A (en) Power digger for landscape gardeners
US20070089329A1 (en) Walk behind trencher for limited depth installations

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): DK FI JP NO SE SU US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LU NL SE