W. R. Grace Co.-conn.

Other

Aiko Engineering Co., Ltd.

Sachio Shimizu

Keiichi Kosuge

A tunnel waterproofing method comprises spraying a primary coating of concrete onto the excavation surface of a tunnel, installing thereon a waterproofing sheet having an adhesive layer operative to bond with concrete, and spraying a secondary coating of concrete against the adhesive side of the waterproofing sheet. Preferably, a buffer water conducting sheet is established between the primary concrete coating sprayed onto the excavation surface and the waterproofing sheet.

Tunnel waterproofing method

A tunnel waterproofing construction method that avoids dripping and fogging during spray application, organic solvents, unpleasant odors, and cracking, while providing workability, superior tunnel waterproofing characteristics, and economic advantage. A primary spray cement concrete is sprayed onto the excavated tunnel surface, and an ambient-temperature vulcanization-type rubber emulsion is sprayed onto the primary concrete, thereby forming a rubber film, and a secondary concrete coating is then established on the rubber surface. The primary spray cement concrete may be used to even out the irregular earthen excavation surface, and a drainage layer may be used along with the primary spray cement concrete surface.

Tunnel waterproofing construction method

In order to elevate dust collecting efficiency by improving a suction work efficiency of a water filter type vacuum cleaner, an air containing dust particles sucked through a sucking opening by virtue of a motor driven blower provided built in a casing of the vacuum cleaner is caused to strike against water previously placed in a water tank to capture inappropriately large dust particles by the water. Moreover, other dust particles pass through a wire netting and then, are sucked together with the water to the blower by channeling the dust particles and water through a suction duct communicated with the blower. The dust particles contained in the sucked air are completely captured by the water by stirring the air and water at a high speed rotation of the blower, and the air and water are then conveyed into the water of the water tank. In the water tank, bubbles are generated by a bubble generating filter to naturally separate the water and the air, whereby clean exhaust air is provided.

Vacuum cleaner

An extra-high pressure water pump includes a cylinder barrel, a piston and a pair of double check valves. The piston is composed of a main piston and a lubricating oil piston. The lubricating oil piston has a double piston ring and is slidably mounted on an additional piston rod connected to the main piston head. Lubricating oil is filled in a lubricating oil room made between the main piston and the lubricating oil piston in the cylinder barrel. The pressure between the lubricating oil and water in the pump is naturally kept at the same level by sliding a position of the lubricating oil piston on the additional piston rod, so that a sudden imbalanced pressure between the lubricating oil and the water in the cylinder barrel does not break the lubricating oil piston. The extra-high pressure water pump supplies extra-high pressured water to its small carriable water jet gun.

Growing community of inventors

Tokyo, Japan

Sachio Shimizu