Abstract: A laser welding device for welding a long sized tubular grounding unit includes a work head arranged to rotate around an outer circumference of two tubular members to be welded, a laser oscillator, and apparatus to transmit the laser beam from the oscillator in sychronism with rotation of the work head. In one embodiment the apparatus to transmit the laser beam includes an optical fiber.

Abstract: A method of removing volatile chlorinated hydrocarbon base materials contained in soil is provided wherein an inorganic compound that is an oxide of an alkali metal or an alkaline earth metal or a sulfate of an alkaline earth metal, which undergoes an exothermic reaction with water, is mixed in powder or granular form with soil containing a water content of 10% to 30% by weight and volatile chlorinated hydrocarbon base material having a normal boiling point in the range of about 60.degree. to about 120.degree. C., the inorganic compound being mixed with the soil in an amount of 0.01 to 0.5 times the weight of the water content.

Abstract: The invention is for an elastic body formed by addition reaction type silicone rubber elastic material. The material is obtained by curing a polysiloxane mixture including at least (a) straight-chain dimethyl polysiloxane having the viscosity of 8000 poise or more at a temperature of 25.degree. C. and terminated with vinyl groups; and (b) resinous organopolysiloxane having at least two vinyl groups and having the viscosity of 10-1000 poise at the temperature of 25.degree. C. and a resin segment with at least one of a 4-functional constitutional unit and a 3-functional constitutional unit, and an oil segment with a 2-functional constitutional unit. The elastic body is used in forming an elastic roller and fixing device using an elastic roller.

Abstract: A magnetic recording and playback apparatus using a magnetic head disposed on a rotating drum for forming oblique recording tracks in succession on a magnetic tape to record or playback serial data along the same, has a tracking control for controlling the height of the magnetic head in the direction perpendicular to the length of the recording track. A speed control is included for controlling the rotating speed of the rotating drum and/or the traveling speed of the magnetic tape in accordance with the bit transfer rate of the serial data so that the magnetic tape travels one reference track pitch while the rotating drum makes an integer number of rotations. A processor is included for compressing the serial data along the time base so that the serial data is recorded while the magnetic head scans the recording track.

Abstract: A reel table assembly for driving a tape reel which has a center hole and a plurality of equally spaced inwardly extending radial teeth formed circumferentially thereof comprises a reel table formed centrally with a reel shaft for carrying thereon the tape reel with the center hole, and a plurality of equally spaced drive pawls which are provided circumferentially in the reel shaft and project radially outwardly of the reel shaft under a resilient force for mesh engagement with the radial teeth of the tape reel. The drive pawls are movable radially inwardly of the reel shaft when the tape reel is carried on the reel table with the radial teeth being in radial abutment on the drive pawls. A friction member is provided on the reel table for direct contact with the tape reel to provide a high degree of friction between the reel table and the tape reel carried on the reel table.

Abstract: In a cassette which comprises a housing having spaced top and bottom walls and a side wall extending between the top and bottom walls along a substantial portion of the housing and an aperture formed in one of the walls and through which, during a recording and/or reproducing operation, access is had to a recording medium that is movably disposed within the housing, the housing having a positioning opening in the bottom wall for receiving a positioning pin therein when the cassette is disposed in an operative position in a recording and/or reproducing apparatus; the cassette having, for indicating a specific condition of the cassette, a connecting hole formed in the housing in communication and alignment with the positioning opening, and a plug element which is slidably inserted in the connecting hole, with the specific condition of the cassette being indicated by the position of the plug element.

Abstract: A mounting structure for tape guide elements, for use with a guide drum adapted to have a tape wound in an .OMEGA.-shaped configuration around its periphery, has a base fixed adjacent to the root portion of the drum and has first and second guide supports for the guide elements. At least one of the guide elements is movable relative to the base between an operative position close to the drum in which it guides the tape about the drum and an inoperative position at a further distance from both the other guide element and the periphery of the drum. A pair of spaced apart positioning members engage the periphery of the drum at its root portion for accurately locating the operative positions of the tape guide elements.