Abstract: A tractor for agricultural purposes, especially for seedbed preparation comprises an engine with a power of at least 30 kilowatt. Further the tractor has a frame (1), at least two power driven wheels (35,40), at least one lifting device (21), and at least one power take-off shaft (55). The weight of the tractor is about 40 kilograms per kilowatt engine power, the engine power is directly transferable to the power take-off shaft of the tractor and the lifting device of the tractor at its coupling points (44, 48) has a lifting power of at least 1000 kilograms.

Abstract: In order to be able to remove a screw that has been installed, in a power-driven screwing head, it is proposed according to the present invention that the recessed portion of smaller diameter be divided into two zones that extend in the longitudinal direction of the sleeve, there being a recessed portion of greater diameter between said zones.

Abstract: Seal for maintaining gas-tight contact between casing wall and, particularly, automatic well swabs. The seal includes an upper portion containing a reinforcing tube and being minimally less in diameter than the casing interior, a tapering midsection and a lower skirt portion contacting the well casing. Also included is a secondary embodiment with an upper portion being substantially less in diameter than the casing interior and reinforcing ribs in the tapering midsection.

Abstract: Patients suffering severe retinal damage and focusing impairment are tested in an area having actual or simulated outdoor illumination by viewing a graphic having colored familiar objects and letters of graduated incremental sizes thereon with colored backgrounds either darker or lighter than the objects and letters involved to ascertain the patient's estimated optimal correction for distance vision. Based on said estimate, the patient is provided with a combination of a soft contact lens between the estimated correction and a correction obtained by traditional testing methods using black letters against a white background in a darkened room, and a plurality of spectacle type lenses in incremental diopter corrections of two or three diopters for training purposes.

Abstract: The grill frame includes a pair of elongated shaft members which are resiliently connected at their first ends so that upon the insertion of the first end into the abdominal cavity of the fowl, the shaft members may be urged against the opposite sides of the abdominal cavity with sufficient force to enlarge the abdominal cavity laterally and to disperse the meat of the fowl to substantially the equal plane. The method of insertion is such that the shaft members are held in substantially close proximity as the first end is inserted through the cavity and the shaft members are allowed to expand outwardly as the first end of the apparatus extrudes out of the rear of the cavity with the apparatus in position within the fowl.

Abstract: Apparatus for recording and reproducing audio signals on flat rectangular recording media comprising a magnetic coating or the like on at least one side. A magnetic head on a swing arm moves across the magnetic media in mutually parallel lines guided by a heart-shaped cam, the recording medium being stationary during recording and reproducing so its visible surface can be examined without difficulty. The heart-shaped cam is of asymmetric configuration, and the magnetic head is pivotably mounted on one end of the swing arm which carries between its ends a cam follower peg which continually engages the heart-shaped cam while under spring loading. The other end of said swing arm is pivotably mounted on a sliding carriage plate which is moved stepwise perpendicularly to the chord of the curved path of movement of the magnetic head for each line. The stepwise perpendicular movement of the sliding carriage plate is produced by a mechanism which is controlled by the reversal of direction of the magnetic head.