Showing papers on "Pressure angle published in 1971"

Vanes for sensing incidence angles of the air from an aircraft

Abstract: Two types of vanes that were used to measure the angle of the airstream with respect to an aircraft are described, analyzed and compared. One type is a rotating vane that is free to align itself with the airstream and the angle is sensed by an angle transducer. The other type is constrained from rotating and the angle is obtained by measuring the force exerted on the vane by the airstream and dividing by the pitot-static pressure. The free vane measures the angle directly and is not sensitive to acceleration, while the constrained vane has a faster response time and has no bearing friction. At an aircraft speed of 70 m sec−1, both vanes are able to resolve changes in angle of less than 0.02°, which corresponds to a gust velocity of about 2 cm sec−1, and respond to within 5% of a step-function change in angle in a distance of less than 5 m. An inflight comparison between the two vanes indicates that they both measure the same angle with a correlation coefficient of 0.97.

Gear drive for a camera and film cartridge

Abstract: A film cartridge includes supply and take-up chambers, a wall interconnecting the chambers to support film therebetween in a plane, and a gear rotatable about an axis for transporting the film across the film plane from the supply chamber to the take-up chamber. A camera for receiving the cartridge includes a cartridge supporting surface and a drive gear engageable with the gear of a received cartridge to define a pressure angle therebetween. The gear axes define a plane which is offset from a normal to the film plane by an angle equal to the pressure angle of the gears, thereby creating a line of force parallel to the film plane so that any tendency of the cartridge to be unseated from the supporting surface in response to the creation of a force component normal to the film plane is negated.

Gear drive for a camera and film cartridge

Abstract: A film cartridge housing encloses a core which is rotatably mounted therein. The housing extends over a gear carried by the spool and defines an opening through which a camera driving gear is insertable for engaging the spool gear and rotating the spool. In a preferred embodiment, the gear axes define a plane which is offset from a normal to the film plane by an angle equal to the pressure angle of the gears, thereby creating a line of force parallel to the film plane. By arranging for such line of force to pass through a cartridge-supporting surface in the camera at a position where the film cartridge contacts the surface, any tendency of the cartridge to be unseated from the supporting surface in response to the creation of a force component normal to the film plane is negated.