WO1994027750A1

WO1994027750A1 - Hydraulic pipe cleaning and root cutting apparatus

Info

Publication number: WO1994027750A1
Application number: PCT/FI1994/000163
Authority: WO
Inventors: Mikko Kustaa Nummela
Original assignee: Tumo Oy
Priority date: 1993-05-31
Filing date: 1994-04-27
Publication date: 1994-12-08
Also published as: FI93248B; FI932483A0; FI93248C; AU6540194A

Abstract

A hydraulic pipe cleaning and root cutting apparatus for unblocking blockages in pipes or the like and cutting roots grown therein. The apparatus is driven by a hydraulic motor (10), which operates the cutting blades (42) and the chains (24) that move the apparatus. The chain mechanisms (30 and 31) center and tighten the apparatus inside the pipe. The necessary tightening force is provided by a hydraulic cylinder (33), which is reversible by a spring (38). As the moment of the cutting blades (42) increases, the compression force of the chains (24) increases, which prevents the apparatus from swinging around. The cutting blades (42) are spread by centrifugal force, and they are curved and self-sharpening.

Description

Hydraulic pipe cleaning and root cutting apparatus

The invention relates to an apparatus and sys¬ tem for unblocking pipes or the like. Drain pipes blocked e.g. by roots can be unblocked with the appar¬ atus. The pipe systems and unblocking operation can also be supervised if the apparatus is provided e.g. with a television camera. The hydraulic pipe cleaning and root cutting apparatus comprises necessary electric and hydraulic machine units, control valves, hydraulic hoses and an actual hydraulic pipe cleaning and root cutting apparatus, which comprises a hydraulic motor, chain mechanisms, a frame, a shaft and cutting blades.

Blocked drain pipes have caused considerable problems to communities. Particularly in areas where the drain pipes need not be sunk very deep, roots pose a severe problem. No good solutions have been found to the problem before this. Instead, several solutions to the removal of normal blockages exist. A previously known way of removing a blockage is, naturally, to use water, which usually removes the blockage if used in a sufficient quantity. In more advanced versions, pressurized water jets are used. Especially good results are naturally obtained by high pressure water jets. However, methods like these are difficult to use in long lengths of pipe.

It is also known to remove blockages mechanic¬ ally. Different kinds of wire cable drawn blade systems have been used. Generally, their drawback has been that they are difficult to control, and variation in pipe joints has caused problems.

Apparatuses the most closely related to the invention are based on root cutting means working pri¬ marily by high pressure water: pressurized water rotates the blade end on the acting or reacting force principle. No sufficient power is obtained by this method to guarantee power needed for the cutting operation. Power is generated in turbine driven apparatuses such that the blade end is rotated at a high speed of rotation, where- by energy is stored in the rotating blade end. Kinetic energy is then converted by means of welding force into work needed for the cutting operation.

Since the torque of these apparatuses is small, the speed of rotation does not increase in a pipe filled with water but the blade end rotates slowly, and thus no power is generated. Also, the propulsion power of water driven apparatuses is small, so their ability to move is rather limited. In addition, apparatuses of this kind operate blindfold since the water splashing around prevents the use of a camera. On account of the above, it is impossible to supervise the operation of a cutter by controls. Further, the power needed by hydraulic turbine driven cutters is multiply tenfold as compared e.g. with hydraulic root cutters. The object of the hydraulic pipe cleaning and root cutting apparatus according to the invention is to remedy the above deficiencies and drawbacks. The inven¬ tion is characterized by what is stated below in the attached claims. One of the advantages of the apparatus accord¬ ing to the invention is that due to the structure, the apparatus is self-centering. The apparatus is also self- tightening, which prevents it from swinging around as the cutting power increases. Another considerable advantage is that the apparatus moves independenly.

Because the apparatus is hydraulically driven, the torque of the blade of the apparatus according to the invention is great and the speed of rotation can be regulated. It is also advantageous that the hydraulic pipe cleaning and cutting apparatus is easy to use in pipes of different diameters.

Unpressurized, the apparatus presses together and can be easily moved in a pipe. The apparatus accord- ing to the invention does not have such elements or projecting parts that would hinder pullout. Since the blades are self-regulating, changes in cross-section in pipe joints do not pose problems. The blades can also be rotated when the apparatus is immobile. The blades are self-sharpening. The operation of the apparatus can be supervised through a television camera.

The apparatus according to the invention can be fully controlled by the inlet and outlet valves, by regulating the pressure difference, pressure level and direction. The apparatus according to the invention can operate under water and in pipes partly filled with grit.

The apparatus according to the invention will be described in the following with reference to the attached drawings, wherein

Fig. 1 shows a schematic view of the connecting pattern of a hydraulic pipe cleaning apparatus and addi¬ tional apparatuses,

Fig. 2 shows a side view of a hydraulic pipe cleaning and root cutting apparatus according to the invention,

Fig. 3 shows a partly cross-sectional side view of the invention,

Fig. 4 shows cross-section I-I of the apparatus according to the invention, and

Fig. 5 shows cross-section II-II of the appar¬ atus according to the invention.

Fig. 1 shows the connecting pattern of the apparatus according to the invention. A vehicle 1 carries the necessary hydraulic machine units and power source. Control valves are in a control centre 2. Hydraulic hoses and pipes are indicated by reference number 3. A reel that facilitates the handling of the hoses is indicated by 4. The hydraulic hoses 3 are con- nected with an apparatus 6 according to the invention by bayonet connectors 5. Electric cables and switches are indicated by 7 and 8.

In Figs. 2 and 3, an inlet and outlet valve is indicated by 9. A hydraulic motor 10 functions as the power source. A dummy coupling is indicated by 11. A drive shaft 12 is surrounded by a manifold 13. A housing of the coupling is referred to by 14. To the shaft 12 is fastened a gear 15, which runs a drive wheel 17 of three herringbone gears 16. A housing around them is indicated by 18. Reference numbers 19 and 20 indicate shafts of the herringbone gears, and a screw and a screw wheel are 21 and 22. A housing 23 of the herringbone gear is fastened to a housing 18 by screws. At the end of a shaft 20 is a sprocket gear 25 running a chain 24. The chain is controlled by controls 26 and 27. A bending end 28 is provided with a tension spring 29. Chain 24 expansion means 30 and 31 are mounted by pegs 32 on the controls 26 and 27 and on a cylinder 33. Seals 34 are arranged between the manifold 13 and the moving cylinder 33. In the manifold 13 there is a neck 35 at the cylin¬ der 33, whereby an annular space 36 is formed. A stop face 37 of the cylinder 33 operates as a piston. The cylinder 33 is returned to the start position by a spring 38, which is supported by a frame 39 fastened to the manifold 13 by a screw 40. Ball bearings of the shafts are indicated by 41. A fastening means for cut¬ ting blades 42 is indicated by 43. The blades 42 are located in apertures 44, mounted on pegs 45. The maximum spread angles of the blades 42 are set by screws 46. A hydraulic hose 47 runs from the valve 9 to the cylinder 33, which controls the compression force of the chains 24.

The pipe cleaning and root cutting apparatus according to the invention is used as described below. If the pipe to be unblocked is e.g. a drain pipe, a vehicle 1 provided with hydraulic machine units and a power source is driven next to a drain pit. The pipe cleaner 6 is connected with hydraulic hoses 3 by bayonet connectors 5. The hydraulic pipe cleaning and root cutting apparatus is disposed in the pipe to be unblocked. A gate valve is used for arranging hydraulic liquid to flow to the hydraulic motor 10. The valve 2 also conducts pressure to the cylinder 33. The hydraulic motor 10 rotates - via the coupling 11 - a shaft 12, in which is arranged a gear 15, which conveys the rotary movement via the herringbone gears 16 to the sprocket gears 25, which run the chains 24 pressed against the walls of the pipe. Since there are three traction chains 24 arranged radially, the chains automatically center the apparatus.

When the pressure in the integrated cylinder 33 rises sufficiently, it exceeds the springback factor of the spring 38 and expands the chain 24 expansion mechanism 30 and 31. The mechanism operates like a normal lever mechanism.

The rotation speed of the blades 42 and the traction speed of the chain 24 are regulated by increasing and decreasing the volume flow of the hydraulic fluid. When the blades 42 meet a blockage, the pressure in the system increases. The power conveyed by the hydraulic cylinder 33 increases, and the chains 24 bite more firmly on the pipe. In other words, the appar¬ atus is prevented from swinging around as the stress of the blade changes rapidly. The blades 42 spread to their maximum breadth, which is limited by a screw 46 with the aid of centri¬ fugal force. If the blade does not spread to the breadth set, the outer edge of the blade rubs against the pipe, sharpening itself. Since the blades 42 are curved along their entire length, they do not catch even in the pipe joints.

To the frame 39 can be fastened a television camera, by which the progress of the pipe cleaning operation can be supervised. Since the blades 42 rotate slowly, no splashes occur, which greatly facilitates supervision.

When a desired portion of the pipe has been unblocked, flow direction is changed, and the chains 24 pull the apparatus back to the start position. It is naturally also possible to remove the flow and pressure, whereby the spring 38 presses the cylinder 33 to the start position and the expansion mechanisms 30 and 31 contract. The apparatus can then be pulled out of the pipe.

Claims

1. A hydraulic pipe cleaning and root cutting apparatus for unblocking blockages in pipes or the like and cutting roots grown therein, the system comprising necessary electric and hydraulic machine units (1 ) , control valves (2), hydraulic hoses (3) and a hydraulic pipe cleaning and root cutting apparatus ( 6), which comprises a hydraulic motor (10), chains (24), chain mechanisms (30 and 31), a frame (39), a shaft (12) and cutting blades (42), c h a r a c t e r i z e d in that

- the root cutter ( 6 ) is driven by a hydraulic motor (10), as is known per se, the motor comprising moveable chains (24) and rotating blades (42) , - to adjust the speed of rotation and moment of the hydraulic motor (10), the control valves (2) controlling the inlet and/or outlet flow regulate the volume flow and the pressure level, and that the com¬ pression force of the chains (24) against the pipe can be regulated by a hydraulic cylinder (33), which is controlled by said valves (2), and

- the hydraulic pipe cleaning and root cutting apparatus (6) is self-centering, as is known per se, due to the chains (24) arranged radially, and that the compression force of the chains (24) increases as the moment of the blades (42) increases.

2. The apparatus according to claim 1, c h a r a c t e r i z e d in that the hydraulic cylinder (33 ) for regulating the compression force of the chains (24) is arranged around the manifold (13), that the expansion means (30 and 31) are articulated with the cylinder (33), whereby the expansion means (30 and 31 ) form articulation mechanisms for tightening the chains (24) against the walls of the pipe, and that said articulation mechanism is contractible by a spring (38).

3. The apparatus according to claim 1, c h a r a c t e r i z e d in that the curved blades (42) are mounted on pegs (45) arranged in a blade fastening means (43) in the circumferential direction such that the maximum breadth can be regulated by screws (46) arranged in blade (42) holders.

4. The blade (42) according to claim 3, c h a r a c t e r i z e d in that the blades sharpen as they rub against the walls of the pipe.

5. The apparatus according to claim 1, c h a r a c t e r i z e d in that since the diameter of the pipes to be cut may vary greatly, the apparatus ( 6) can be provided with larger and/or smaller blades (42) and expansion means (30 and 31), which broadens the area of operation.

6. The apparatus according to claim 1, c h a r a c t e r i z e d in that a television camera is arranged in the frame (39) for supervising and check¬ ing the work.

7. The apparatus according to claim 1, c h a r a c t e r i z e d in that the hydraulic oil is mineral oil, or environmentally friendly vegetable oil or water.