Abstract: In a video recorder with a rotary head drum, a lower drum (1) and drum base (2) are joined together by laser welding to simplify assembly and reduce manufacturing cost.

Abstract: According to a first aspect the present invention is related to a head drum arrangement allowing a much easier mounting of the rotary transformer. The head drum arrangement comprises a non-rotating lower drum and a rotating upper drum, which are connected by a shaft fixed in the lower drum. The upper drum is mounted on the shaft by a bearing and preferably by two ball bearings. A rotary transformer is arranged between the lower drum and the upper drum having a fixed stator and a rotor rotating jointly with the upper drum. The rotor is non-positively held in its position by the magnetic force of a permanent magnet accommodated in the upper drum.

Abstract: According to a first aspect the present invention is related to a head drum arrangement allowing a much easier gap adjustment of the rotary transformer. The head drum arrangement comprises a non-rotating lower drum and a rotating upper drum, which are connected by a shaft fixed in the lower drum. The upper drum is mounted on the shaft by a bearing and preferably by two ball bearings. A rotary transformer is arranged between the lower drum and the upper drum having a fixed stator and a rotor rotating jointly with the upper drum. The stator and the rotor are separated by an air gap. Finally, a compressible, elastic spring is arranged between the lower drum and the upper drum, such that the length of the spring defines the air gap between the stator and the rotor of the rotary transformer. Advantageously, the invention allows defining the air gap of the rotary transformer without requiring additional members like washers, spacers or something similar.

Abstract: As is well known from video recorders, the rotary drum comprises a rotary part (upper drum) and a stationary part (lower drum), and forms a drum unit with a drum base (2) by means of which the drum is being arranged with a tilt angle with respect to the plane of recorder's tape deck chassis.

Abstract: A current limiter comprises an extinguishing chamber 16 of small volume, in which there are housed a pair of contacts 28, 30 and an insulating shield 40, capable of moving to an active position inserted between the contacts 28, 30, and of subdividing the chamber 16 into two parts each of which contains one of the contacts 28, 30. The movement of the insulating shield 40 to the inserted position between the contacts 28, 30 is favored by the action of a piston 48 subjected to the pressure prevailing in the extinguishing chamber 16.

Abstract: A physico-chemical cleaning process for the inner walls of a reactor which serves to maintain these walls in a state close to their main initial characteristics necessitated by a fluorination reaction, said characteristics being degraded by the deposition of a parasitic phase during the reaction, said initial characteristics being maintained by the use of a protective agent belonging to the group constituted by at least one of the reagents, a product resulting from the reaction, a product foreign to the reaction, but compatible with the substances of the main reaction or by the reaction of a third substance with at least one of the reaction substances or a mixture thereof, forming a renewable protective film on the said walls. The protective agent can be deposited by condensation on the walls before, during or after the main reaction, and then vaporized. The protective agent can be in liquid form, and trickling along the walls.