Abstract: A polishing device is formed of a pair of rotatable and elevatable upper supporting members provided with ring shape polishing pads at lower surface peripheries thereof, a pair of rotatable lower supporting members provided with ring shape polishing pads at upper surface peripheries thereof, a rotatable and elevatable disc holding device for holding a disc to be polished, and an arm for supporting the upper supporting members and the disc holding device. The polishing device further includes driving devices for rotating the upper supporting members, the lower supporting members and the disc holding device, respectively. The disc is independently rotated in a direction opposite to a rotating direction of the upper and lower supporting members to improve polishing efficiency. By setting rotating speeds of the supporting members and the disc, a regular working mark can be formed on the disc.

Abstract: The heat from garbage upon incineration and solar heat can be effectively used to make sterilized hot water economically. A sterilized hot-water generator is provided with upper, intermediate and lower tanks in communication with each other. The lower tank includes a combustion chamber which is in communication with heating chambers housed centrally within the upper and intermediate tanks. A solar heat hot-water maker is attached to the front side of the sterilized hot-water generator. A sterilizer is located through the heating chambers in the upper and intermediate tanks to introduce the hot water in the upper tank into an associated sterilizing chamber for sterilization by heating. A fume removing tank is provided to dissolve, in water, fumes generated during combustion. Exhaust gases leaving the fume removing tank are fed to a reducing tank where they are reduced to oxygen, by plants, for example. The oxygen is then released into the atmosphere.

Abstract: The present invention provides a water piping system wherein when a predetermined time elapses after the flow of the water in a hose has stopped, the water is drawn out of the hose, thereby preventing proliferation of various bacteria in the water standing stagnant in the hose and when the temperature of the water drops, the water is completely drawn out of the hose, thereby preventing a water pipe from rupturing or cracking in the wintertime. The water pipe including a reducing valve which is at a position higher than a waterstop valve is connected with a hose through a first electromagnetic valve. The required number of second electromagnetic valves are located intermediate on the hose. When a predetermined time elapses after the flow of the water through the hose has stopped, the first valve is temporalily closed while the second valves are opened.