Semi-automatic adjusting delay for an electronic particle separator

• US 3,963,606 A
• Filed: 06/03/1974
• Issued: 06/15/1976
• Est. Priority Date: 06/03/1974
• Status: Expired due to Term

• Current Assignee: Coulter Electronics, Inc.
• Original Assignee: Coulter Electronics, Inc.
• Inventors: Hogg, Walter R.
• Primary Examiner(s): Lutter, Frank W.
• Assistant Examiner(s): Hill, Ralph J.
• Application Number:
  US05/475,670
• Time in Patent Office: 743 Days
• Field of Search: 209/3, 209/4, 209/111.5, 209/111.7, 209/111.8, 324/71 CP, 356/170, 356/171, 356/39, 250/222 PC, 250/364
• US Class Current: 209/3
• CPC Class Codes: B07C 5/36 Sorting apparatus characterised by the means used for distribution sorting according to destination B07C3/003, B07C3/02
• CPC Class Codes: G01N 15/1427 with the synchronisation of components, a time gate for operation of components, or suppression of particle coincidences
• CPC Class Codes: G01N 15/149 specially adapted for sorting particles, e.g. by their size or optical properties
• CPC Class Codes: G01N 2015/1406 Control of droplet point

Abstract

A particle separator for separating particles suspended in a fluid according to certain characteristics, including a device for adjusting an electrical delay to be equal to the time between the emergence of a particle from a jet forming aperture to the point of break-off. The device includes a variable scale graticule coupled to a potentiometer.

Claims

1. A device for adjusting an electrical delay to a time interval between two occurrences of a moving particle in an apparatus for classifying particles suspended in a fluid, in which said apparatus comprises:

A. nozzle means including a nozzle connected to a fluid reservoir for generating a fluid jet,

B. means connected to the nozzle means for pulsating the fluid jet so as to separate same into droplets at a break-off point,

C. sensing means located at the outlet of the nozzle means for producing an electric quantity in response to a selected parameter of a passing particle,

D. means disposed adjacent the fluid downstream of the sensing means for charging each droplet with a potential related to the electric quantity produced by the sensing means,

E. electrical delay means, the input thereof being coupled to the sensing means and the output thereof being coupled to the charging means,

F. first and second means associated with the electrical delay means for adjusting the delay of said electrical delay means,

G. means situated downstream of the charging means for deflecting each droplet by an amount related to said parameter of the particle,

H. collecting means supported downstream of the deflecting means for collecting the droplets in relation to the amounts of deflection,

I. microscope means arranged in front of the nozzle means and means for illuminating same in synchronization with said pulsating means,

J. movable scale means associated with the microscope means and including a graticule having a reference line and at least one nonparallel comparison line,

K. position adjusting means connected to the nozzle means for raising or lowering the nozzle until the image of the breakoff point of the jet is on said reference line,

L. graticule adjusting means associated with the graticule for aligning said at least one comparison line with the image of at least one of said droplets, and

M. means for coupling said first and second delay adjusting means to said position and graticule adjusting means, respectively.

wherein, upon completion of said adjustments, the image of the train of droplets is rendered visible, stationary and measurable, and the electrical delay is substantially equal to the time interval between the passage of a particle through the sensing means and the arrival thereof at the break-off point.

2. The device as set forth in claim 1 in which the microscope means comprise a projection microscope and the illuminating means include a stroboscopic light source.

3. The device as set forth in claim 1 in which the movable scale means is coupled to a potentiometer of a RC oscillator for controlling the frequency thereof.

4. The device as set forth in claim 1 including a third adjustment means connected to the nozzle means for placing the jet emerging from the nozzle in the optimum distance from the microscope objective lens.

5. The device as set forth in claim 4 in which the microscope includes prism means for facilitating obtaining a clear image.

6. The device as set forth in claim 1 including a fourth adjustment means for centering the image in the screen.

7. The device as set forth in claim 1 in which said electrical delay means comprises at least one shift register.

8. The device as set forth in claim 1 comprising univibrator means including means for setting the delay time thereof inversely proportional to the distance between droplets.

9. The device as set forth in claim 1 comprising univibrator means including means for setting the delay time thereof directly proportional to the distance between said sensing means and said breakoff point.

10. The device as set forth in claim 1 in which the droplet forming generator includes means for controlling the frequency which controls said electric delay means.

11. The device as set forth in claim 1 including an oscillator circuit comprising a capacitor and means for limiting the peak-to-peak swing and linearizing the ramp from one peak to the other.

12. The device as set forth in claim 11 including first means for providing constant current to the capacitor of the oscillator circuit.

13. The device as set forth in claim 11 including second means for providing constant current to the capacitor of the oscillator circuit.