Centrifuge control system

Claim 2

In a centrifuge apparatus which includes a housing, an electric motor mounted in said housing and including a drive shaft for rotatably driving a rotor head, and a lid mounted on the housing; the combination of a latching mechanism mounted on said housing and including a latch for selectively engaging said lid, a solenoid, linkage means mechanically coupling said solenoid to said latch, tachometer means mounted on said motor for generating an electric signal representative of the angular speed of said shaft, and control circuitry electrically connecting said tachometer means to said solenoid for actuating said solenoid to release said latch only when the speed of rotation of said motor drive shaft falls below a preestablished minimum, a magnetically operated electric switch positioned to be actuated when said lid is in a closed condition, a permanent magnet mounted on said lid for actuating said switch when said lid is closed, and circuitry electrically connecting said switch in the energizing circuit of said motor to pRevent the motor from being energized until said lid is closed.

Claim 3

The combination defined in claim 1, and which includes a timing circuit for said motor, said timing circuit including pulse generator means and a counter circuit, and circuitry for activating said pulse generator means when said motor is energized, so as to cause said pulse generator means to introduce counting pulses to said counter, and further circuitry responding to a predetermined count of said counter for deenergizing said motor.

Claim 4

The combination defined in claim 1, in which said counter circuit includes a plurality of electric lamps connected to be individually energized as said counter is stepped from one count to the next, and in which said further circuitry includes a photocell mechanically adjustable to be energized by a selected one of the aforesaid lamps to deenergize said pulse generator and counter after said counter has been stepped to a predetermined count.

Claim 5

In a centrifuge apparatus which includes a housing, an electric motor mounted in said housing including a drive shaft for rotatably driving a rotor head, a timing circuit for said motor including: pulse-generating circuit means for generating electric pulses having a predetermined repetition frequency, a counter circuit coupled to said pulse-generating circuitry and responsive to the pulses therefrom to be stepped from one count to another, and further circuitry coupled to said counter and responsive to a predetermined count of said counter for deenergizing said rotor and for deactivating said counter and said pulse-generating circuit means, in which said counter includes a plurality of electric lamps respectively connected in circuit therewith to be successively energized as the counter is stepped from one count to another, and in which said further circuitry includes a photocell movable to be optically coupled to a selected one of the aforesaid lamps, so as to deenergize said motor and deactivate said pulse-generating circuit means and said counter after said counter has reached a predetermined count.

Claim 6

In a centrifuge apparatus which includes a housing, an electric motor mounted in said housing including a drive shaft for rotatably driving a rotor head, a timing circuit for said motor including: pulse-generating circuit means for generating electric pulses having a predetermined repetition frequency, a counter circuit coupled to said pulse-generating circuitry and responsive to the pulses therefrom to be stepped from one count to another, and further circuitry coupled to said counter and responsive to a predetermined count of said counter for deenergizing said rotor and for deactivating said counter and said pulse-generating circuit means, in which said counter includes a plurality of electric lamps respectively connected in circuit therewith to be successively energized as the counter is stepped from one count to another, and in which said further circuitry includes a photocell movable to be optically coupled to a selected one of the aforesaid lamps, so as to deenergize said motor and deactivate said pulse-generating circuit means and said counter after said counter has reached a predetermined count.