Back to results
US 4,818,926 AGranted
Tachometric device driven by an electric motor
AssigneeVeglia Borletti S.r.l.
InventorRodolfo Bitetti
Life of this patent
Estimating the term…
Abstract
A tachometric device is provided with a D.C. electric motor a shaft of which drives a pair of permanent magnets to rotate. A first permanent magnet controls a speed indicator unit; a second permanent magnet is rotatably mounted within a winding the terminals of which are connected to a negative feed back circuit for controlling the speed of the motor.
Claims5
A tachometric device, comprising:
- a first electrical signal generator for generating a first electrical signal dependent on the speed of rotation of a first shaft;
- an electric motor including a shaft;
- a magnetically controllable speed indicator unit;
- a first permanent magnet coupled for rotation with said motor shaft and magnetically cooperating with said speed indicator unit;
- a second electrical signal generator, integrally contained within said motor, for generating a second electrical signal dependent on the speed of rotation of said motor shaft, said second electrical signal generator comprising a second permanent magnet coupled for rotation with said motor shaft, an electric winding rigidly fixed to the body of said motor in a position substantially facing said second permanent magnet and providing said second electrical signal induced by the rotation of said second permanent magnet;
- and
- a processing circuit having a first and a second input connected to the outputs of said first and second electrical signal generators, respectively.
4 more elements
Dependencies are inferred from the claim text.