Generating tooth profiles with a cutter having cutting edges which move about a common cutter axis, the workpiece also being rotated about an axis, the workpiece and cutter undergoing relative movement along a path, cutter and workpiece having basic rates of movement about their respective axes, with one of the basic rates being increased or decreased by a differential rate depending upon the rate of said relative movement, so that for each desired tooth profile the cutting edges will make a ser...

Apparatus for making gears of hyperboloidal form, comprising a cutter having profile generating cutting edges mounted for movement about a common axis, and a support for a workpiece rotatable about a workpiece axis; the support and the cutter being mounted for relative pivotal movement about a feed axis nonparallel to the workpiece axis; the support and the cutter having basic rates of simultaneous movement about the workpiece and cutter axes, respectively, in the absence of the pivotal movement...

Apparatus for making gears, featuring a workpiece support mounted to provide rotation of the workpiece about its axis at a basic rate; a cutter having profile generating cutting edges mounted for rotation about a cutter axis at a basic rate bearing a ratio to the basic workpiece rate dependent upon the ratio of the number of profiles being generated to the number of profile generating cutting edges in the cutter, the cutter axis being at an angle to the workpiece axis which differs from 90.degre...

In gear making apparatus a rotary cutter has a tool holding body with a plurality of tools removably mounted in recesses spaced around the body periphery, each tool having a profile generating cutting edge at the intersection of two planar surfaces, each recess having at least one planar surface in flush contact with one of the planar surfaces of the mounted tool to positively locate the cutting edge so that all cutting edges lie on a single surface of revolution.

An apparatus for checking the contents of a store of a computer which is normally under control of a train of timing pulses, and in which the store is normally controlled by an address register in the computer, comprises a switching arrangement responsive to a command signal to remove the pulses from the remainder of the computer then automatically being returned to control of the pulses and the sum being retained for comparison with a known quantity.

An electronic fuel control for a gas turbine with a power turbine engine includes a power turbine actual speed transducer, a power turbine desired speed control and a control circuit including an output difference amplifier the output of which determines the quantity of fuel supplied to the engine. To guard against failure of the transducer a "high wins" gate receives signals from the transducer and the amplifier and a second difference amplifier has its two inputs connected to the gate and to t...

A fuel control system for a gas turbine engine having a plurality of burner manifolds, comprising a spill valve for spilling excess fuel from a high pressure fuel supply line and a plurality of control arrangements, each of which is arranged to control fuel flow rate to a respective one of the manifolds and comprises a metering valve and a regulator for regulating the pressure drop across the metering valve, the spill valve having a cylinder containing a piston which is movable to close the spil...

A fuel control system for a gas turbine engine includes means for producing an electrical signal corresponding to engine speed, means for producing an electrical signal corresponding to the desired engine speed, a first difference amplifier for producing an error signal corresponding to the difference between the desired and actual engine speeds, a limit circuit which imposes a variable limit on the magnitude of the error signal, an integrater connected to produce an output signal corresponding ...

An electronic fuel control for a gas turbine engine having a gas generator and a separate power turbine includes gas generator and power turbine actual speed transducers, gas generator and power turbine desired speed signal generators, error amplifiers connected to the respective transducers and generators, a "low wins" gate for selecting the lower error, an acceleration control limiter passing the selected signal from the gate to an integrator and an output difference amplifier producing an out...

A fuel control system for an engine, having a pump operable to supply an output flow of fuel, engine fuel flow regulation means operable to regulate the pump output flow, and pump control means operable to vary an output rate of the pump according to an operational condition of the engine fuel flow regulation means.