Abstract: An aromatic polyamide and/or aromatic polyimide film suitable as a support in a magnetic recording medium excellent in runnability and scratch resistance and good in S/N ratio comprises an aromatic polyamide and/or aromatic polyimide as a main component, with particles present in the film, which film has characteristics which satisfy the following formulae:10 nm.ltoreq.dmax.ltoreq.300 nm (1)3.ltoreq..rho.(dmax)/.rho.(dmin).ltoreq.100 (2)or10 nm.ltoreq.dmax.ltoreq.300 nm (3)3.ltoreq..rho.(dmax)/.rho.(d").ltoreq.100 (4).rho.(dmax)/.rho.(dmin)>100 (5)where dmax is the depth from a first surface of the film at which the particle density shows the first maximal value; dmin is the depth at which the particle density shows the first minimal or minimum value in a range from dmax to 1 .mu.

Abstract: This invention relates to an image transfer material for thermal recording of the electric current-conducting type. Since the image transfer material of the present invention comprises an aromatic polyamide film with a thickness of 1-10 .mu.m, which contains 10-40% by weight of carbon black, and has a tensile strength in at least one direction of not less than 8 kg/mm.sup.2 and a dimensional change in at least one direction at 200.degree. C. under a load of 1 kg/mm.sup.2 of 5% or less, and an ink layer formed on the film the image transfer material of the present invention is a thin image transfer material which excells in heat resistance and anti-pinhole property, which makes it possible to conduct high speed printing and to promote the printing quality.

Abstract: Herein disclosed is a four-way valve for switching the cooling and heating modes of an air conditioner. The four-way valve includes: a first valve body of a cup shape having its closed wall formed with an outlet port and two circuit ports. A second valve body is provided having its root fitted fixedly on the first valve body and an inlet port formed at the side opposite to the body root. A cylindrical valve member is fitted rotatably in the first valve body having its one half formed in its end portion with an arcuate groove for providing alternate communication between the outlet port and the circuit ports and its other half formed with two communication ports. A member is provided for restricting the rotations of the cylindrical valve member. A magnetic member is provided for magnetically rotating the valve member when energized. A collar is disposed on the valve member and made irrotational but movable in the axial direction.

Abstract: In a valve unit provided with a straight-cylindrical valve housing having a thick barrel portion and a thin head portion; an inward-facing valve seat on the upper edge of the head portion; and an upper edge on the head of an internal valve element, the upper edge engages the inward-facing valve seat when a lower passage in the valve housing is defined.

Abstract: Disclosed is a magnetic recording medium which comprises a film of an aromatic polyamide having at least 50 mole % of recurring units represented by the following general formula: ##STR1## wherein m and n are integers of from 0 to 4, with the proviso that the case where both of m and n are 0 is excluded,and at least one high performance magnetic layer of a metal or metal compound vacuum-deposited on the aromatic polyamide film. This magnetic recording medium shows a reduced dimensional change and is substantially free of curling or breakage due to elongation, and is excellent in flatness and adhesive strength between the base film and the magnetic layer. Accordingly, this magnetic recording medium is suitable for high-density magnetic recording.