Abstract: A method of engraving which accommodates changes in copper hardness, variations in head linearities, worn stylus, and the like. The method involves the cutting of midtone test cells, as well as highlight and full width test cells. The widths of the test cells are measured and used to establish slopes and offsets for adjustment lines, which in turn are applied inversely to transform a desired cell width into an engraving drive signal. The technique assures that the computed engraving drive signal will produce the desired cell width.

Abstract: A computer controlled engraving system having a non-volatile memory loaded with error coefficients. The error coefficients represent previously experienced differences between computed cell configuration values and corresponding configuration values for cells actually engraved. Sets of error coefficients are tabulated and stored in the memory along with associated setup parameters. Setup of the engraving system for a new job is swiftly accomplished by using values of the setup parameters to retrieve sets of approximate error coefficients, from which interpolated values are obtained. The interpolated values of the error coefficients then are used for calculating configuration control parameters such as AC gain, video gain and white offset.

Abstract: A tool for use in guiding a seat belt through or around one or more child safety restraints to secure the restraints to the seat of a vehicle, the tool comprising an elongated shank having a handle at one end of the shank to be gripped by a user, and clasping means at the opposite end of the shank for engaging the male half of the seat belt locking assembly.

Abstract: A method of ventilating an air breathing animal at a high frequency. A flow of gas is supplied to the first side of a piston mounted within a housing while the flow of gas out of the housing is restricted to elevate the pressure on the first side of the piston. A flow of gas is also supplied to the second side of the piston, which is connected to an air breathing animal, while the piston is alternately moved back and forth within the housing at a selected frequency, amplitude and period, thereby alternately forcing gas into and drawing gas out of the animal. The flow of gas out of the animal is also restricted to elevate the pressure on the second side of the piston. The flow of gas to the first side of the piston both cools the piston and housing and helps to equalize the pressures on both sides of the piston, helping to insure accurate conversion of the mechanical movement of the piston into a pressure wave in the gas on the second side of the piston.