Abstract: A dual rotary cam may include a first rotating unit, a second rotating unit, a first rod, a second rod and a transmission device. The transmission device has an active gear, two connecting gears, and two passive gears. The active gear is driven by a motor to drive the connecting gears. A decelerating gear that is co-axially disposed with the connecting gear is used to connect the passive gears. The passive gears co-axially connect with the connecting portions of the first rod and second rod. The gear motion between the active gear, connecting gears, passive gears and decelerating gear can be arranged to adjust the gaps therebetween to achieve a goal of seamless transmission of the rotary cam.

Abstract: A dual rotary cam may include a first rotating unit, a second rotating unit, a first rod, a second rod and a transmission device. The transmission device has an active gear, two connecting gears, and two passive gears. The active gear is driven by a motor to drive the connecting gears. A decelerating gear that is co-axially disposed with the connecting gear is used to connect the passive gears. The passive gears co-axially connect with the connecting portions of the first rod and second rod. The gear motion between the active gear, connecting gears, passive gears and decelerating gear can be arranged to adjust the gaps therebetween to achieve a goal of seamless transmission of the rotary cam.

Abstract: The center line average roughness (Ra) of the slit inner surfaces is made in a predetermined range of 5.0 .mu.m according to the present invention, and the straightness (W1) in the delivery direction of the coating solution thereof and the straightness (W2) in the perpendicular direction to the delivery direction thereof are made in predetermined ranges respectively in preferred embodiments. Thereby, development of wrinkles and inclined elongation in the tape itself are prevented when wound on a roll, the productivity is increased, and the product quality is improved.

Abstract: A coating apparatus having an extrusion type coating head to form a coating on the surface of a support by extruding a coating liquid continuously or successively from a slit, wherein the slit is tapered so as to expand or become wider gradually from its inlet end so as to allow the coating liquid to be extruded toward its outlet end and apply the coating liquid onto the surface of the support and wherein an opening slit width (d1) at the inlet end of the slit and an opening slit width (d2) at the outlet end thereof satisfies the following relations:5% .ltoreq.[(d2-d1)/d1].times.100.ltoreq.20%.The arrangement of the slit can form a coating in a uniform film thickness by preventing the occurrence of irregularities or streaks on the surface of the coating or by suppressing a variation in film thickness.

Abstract: In a coating apparatus having an extrusion coating head, the working value H of a back end edge which corresponds to an end portion at the downstream side of a support feeding direction of a back edge of the extrusion coating head is set to 25 .mu.m or less, and the straightness of said back end edge with respect to the coating width is set to 5 .mu.m or less. Accordingly, a coating operation to form coated films at a stable thickness can be stably performed without occurrence of streaks and coating unevenness on the films, and a judgment on coating surface characteristics can be readily performed without actually carrying the coating operation.

Abstract: In an extrusion type coating head according to the present invention, a center line average roughness (Ra) of an inner wall surface of a pocket is made in a predetermined range of 3.5 .mu.m or less and preferably a curvature part is provided, in the part where a surface of a slit joins to a surface of the pocket, which has the radius of curvature R of within a predetermined range. By these configurations, an easiness of cleaning in the pocket of the extrusion type coating head which is difficult to be cleaned is remarkably improved in particular, the rate of operation is improved, labor is saved, and adverse effects are prevented that might be brought by insufficient cleaning on the product coating such as streak generated on the coating surface and thickness fluctuation in the coating.

Abstract: To manufacture a magnetic recording medium with reduced coating defects by effectively and reliably removing foreign matter that causes coating striations.In a manufacturing method for a magnetic recording medium that includes a process in which a magnetic layer is formed on a flexible support, the aforementioned magnetic layer is formed after cleaning the aforementioned flexible support by bringing it into contact with a rotating cleaning roll, the contact surface of which consists of at least an adhesive substance or with a cleaning member, the contact surface of which consists of at least a porous polymer and so providing a manufacturing method for a magnetic recording medium in which foreign matter, which causes coating striations, can be efficiently and reliably removed and in which it is possible to manufacture a magnetic recording medium with reduced coating defects.