Centrifuges

• US 3,982,162 A
• Filed: 04/19/1974
• Issued: 09/21/1976
• Est. Priority Date: 08/13/1969
• Status: Expired due to Term

• Current Assignee: David William Olliffe
• Original Assignee: David William Olliffe
• Inventors: Olliffe, David William
• Primary Examiner(s): Dobeck, B.
• Application Number:
  US05/462,540
• Time in Patent Office: 886 Days
• Field of Search: 233/24, 233/26, 318/313, 318/326, 318/327, 318/346, 318/369, 318/314
• US Class Current: 388/811
• CPC Class Codes: B04B 13/00 Control arrangements specially designed for centrifuges; Programme control of centrifuges control arrangements for feed, charge, or discharge B04B11/00
• CPC Class Codes: B04B 13/003 Rotor identification systems
• CPC Class Codes: G01P 1/106 by comparing the time duration between two impulses with a reference time
• CPC Class Codes: G01P 3/60 by measuring or comparing frequency of generated currents or voltages frequency comparators H03K5/26
• CPC Class Codes: Y10S 388/911 Phase locked loop
• CPC Class Codes: Y10S 388/921 Timer or time delay means
• CPC Class Codes: Y10S 388/933 Radiant energy responsive device

Abstract

An analytical centrifuge to receive a plurality of different rotors each carrying a track with a segment having a light reflective property distinct from adjacent regions of the track and having a length along the track which is related to the maximum desired speed of the rotor, the centrifuge having optical sensing means for sensing said segment and a time comparator for comparing the duration of the signal obtained by the sensing means in each rotor revolution with a fixed time to sense when the maximum desired speed is reached. Analytical rotors also carry a further track having distinct segments corresponding to respective compartments of the rotor and which are optically sensed to provide in conjunction with the signal obtained from the first-mentioned segment gating signals for examining selectable compartments of the rotor one-by-one.

Claims

1. In a centrifuge operable with a variety of rotors, with each rotor there being associated a maximum speed of rotation defined by an element carried by a respective one of said rotors, the centrifuge having means for sensing said element to prevent increase in the speed of rotation of said rotor when the maximum speed is reached, the improvement which resides in said element being a surface portion having, along an annular path centered on the axis of said rotor, a length defining the maximum speed and a property along its length which distinguishes said surface portion from the remainder of said annular path;

said sensing means being arranged to sense said property of the surface portion without contact with said rotor to produce a signal having a time duration which is a function of said length; and

means for sensing when the time duration of the signal has fallen to a predetermined value, wherein said rotor is an analytical rotor with at least two compartments to receive samples and carrying distinct portions corresponding to respective compartments in addition to said surface portion which also defines a predetermined angular position of said rotor, the centrifuge comprising a compartment examining system for sensing radiation passed through said compartments to produce corresponding signals;

at least one signal path to which the signals will be fed;

means for controlling which of the signals in each revolution of said rotor is conveyed through said signal path;

said sensing means being also arranged to sense said distinct portions without contact with said rotor and operable in conjunction with said controlling means so that said signal path will carry a signal corresponding to just one of said compartments, and so that said one compartment will be defined.

2. The improvement in the centrifuge as defined in claim 1, comprising two signal paths, and wherein said controlling means are such that signals will be produced in each revolution on said signal paths, the signals corresponding to respective ones of two of said compartments.

3. The improvement in the centrifuge as defined in claim 2, further comprising difference forming means for producing a third signal corresponding to the difference between the data conveyed by the two signals on said two signal paths, the latter being coupled to said difference forming means.

4. The improvement in the centrifuge as defined in claim 1, wherein said controlling means includes selector means for selecting at will that one of said compartments to be examined.

5. The improvement in the centrifuge as defined in claim 4, comprising a logic circuit for deriving from the sensed predetermined angular position and a train of pulses, obtained by said sensing means from said distinct portions, separate trains of gating pulses corresponding to respective compartments for gating the signal path.

6. The improvement in the centrifuge as defined in claim 5, comprising two signal paths, and two of said selecting means for the respective signal paths, said logic circuit being connected to supply to each of said selecting means the separate trains of gating pulses, whereby each signal path can be independently gated by selection of particular ones of the separate trains.

7. The improvement in the centrifuge as defined in claim 1, wherein each of said distinct portions has a radiation-affecting property distinct from that of regions adjacent said distinct portion, and said sensing means are radiation sensitive.

8. The improvement in the centrifuge as defined in claim 7, wherein said sensing means are optical sensing means.

9. A centrifuge comprising an analytical rotor with at least two compartments to receive samples and carrying distinct portions corresponding to the respective ones of said compartments and a portion defining a predetermined angular position of said rotor;

a compartment examining system for sensing radiation passed through said compartments to produce corresponding signals;

a signal path to which the signals are fed;

gating means in said signal path for controlling which of the signals in each revolution of said rotor is conveyed through said signal path;

means for sensing said distinct portions without contact therewith to produce signals corresponding to said portions;

logic means connected to receive the signals of said sensing means and to derive therefrom gating signals corresponding to said respective compartments; and

means for selecting any one of the gating signals for transmission to said gating means, so that said signal path will carry a signal corresponding to the radiation passed through just one of said compartments and so that said one compartment will be defined by said selecting means.

10. A centrifuge as defined in claim 9, wherein said sensing means are optical sensing means.

11. A centrifuge as defined in claim 9, wherein said logic means includes a counter arrangement connected to be stepped by the signals corresponding to said distinct portions and to be reset by the signal corresponding to said portion defining a predetermined angular position of the rotor.

12. A rotor suitable for the centrifuge, the rotor having a plurality of compartments to contain samples, carrying a first annular track having a plurality of distinct sensible portions corresponding to respective ones of said compartments, and carrying a second annular track having a sensible portion subtending an angle at the axis of the rotor which defines a maximum desired speed of rotation of the rotor, said sensible portion subtending an angle having a property along its length along said second annular track which distinguishes said sensible portion from the remainder of said second annular track.

13. A rotor as defined in claim 12, wherein said distinct portions subtend equal angles at said axis.