Abstract: An attachment which converts a stationary exercise bicycle into an electronic exercise machine. A base tube of the bicycle frame can be strapped to a floor plate to which an alternator is hinged. The alternator can be raised about the hinge axis so that a drive wheel on the alternator drive shaft is applied to the driven bicycle wheel. The alternator is maintained in its operating position by a rope and cooperating springs. By electrically controlling the field coil of the alternator, the load applied to the bicycle wheel can be varied. Electronic features include programmed exercise routines and visual displays of time, load, speed and pulse rate.

Abstract: A position indicating device which attaches to an X-ray machine is provided with a collar onto which a lead lined cylinder may be threaded. The cylinder has an end plate through which a rectangular opening is formed in order to provide a rectangular X-ray beam for use in cephalometric radiography. When the cylinder is removed, a circular beam is emitted for use in intra-oral radiography.

Abstract: A wire device is pivotally attached to one ear post of a head positioning mechanism of the type used in cephalometric radiography. The wire may be pivoted to an indicating position wherein one of its ends indicates the proper location of the orbital area for correct head orientation. The wire provides a straight line on the X-ray film which represents an indication of the Frankfort plane. The wire may also be pivoted to an out of the way retracted position.

Abstract: An X-ray cassette holder is constructed for use with X-ray equipment to properly position a rectangular film cassette having the longitudinal axis of the cassette oriented either horizontally or vertically. The cassette is received between a pair of vertically spaced channels that are supported on a plate. A pair of levers couple the lower channel to the plate and are pivotal to adjust the spacing between the two channels. A stop plate for horizontally centering the cassette is carried on the lower channel and is moved laterally a preselected distance as the levers pivot. A switch mechanism adjusts the collimator diaphragm controls as the levers pivot to automatically conform the size and orientation of the beam to the size and orientation of the cassette.