ELECTRONIC STRAIN-LEVEL COUNTER

• US 3,733,424 A
• Filed: 07/08/1971
• Issued: 05/15/1973
• Est. Priority Date: 07/08/1971
• Status: Expired due to Term

• Current Assignee: Felix L. Pitts, John L. Spencer
• Original Assignee: Felix L. Pitts, John L. Spencer
• Inventors: Pitts, Felix L., Spencer, John L.
• Primary Examiner(s): Ruehl, Charles A.
• Application Number:
  US05/160,859
• Time in Patent Office: 677 Days
• Field of Search: 73/67.3,88.5R,91 235/92MT,151.3
• US Class Current: 73/764
• CPC Class Codes: G01D 1/18 with arrangements for signalling that a predetermined value of an unspecified parameter has been exceeded G01D1/14 takes precedence
• CPC Class Codes: G01N 2291/02827 Elastic parameters, strength or force
• CPC Class Codes: G01N 3/32 by applying repeated or pulsating forces

Abstract

An electronic strain level counter for obtaining structural strain data on in-flight aircraft. The device counts the number of times the strain at a point on a structural member of the aircraft exceeds each of several preset levels. A dead band is provided at each level to prohibit the counting of small strain variations around a given preset level.

Claims

1. An electronic strain level counter for obtaining strain data on a structural member comprising:

means including a source of constant amplitude electrical pulses for producing electrical pulses having amplitudes indicative of the strain on said structural member;

a generator means receiving said constant amplitude electrical pulses for generating strobe pulses;

a plurality of level detector means with said strobe pulses and said electrical pulses having amplitudes indicative of strain applied to each level detector means;

each of said level detector means having a different amplitude preset into it and including a comparator for comparing said electrical pulses having amplitudes indicative of strain with said preset amplitude and means connected to the output of said comparator and enabled by said strobe pulses for producing an electrical signal each time the amplitude of one of said electrical pulses indicative of strain exceeds said preset amplitude and for providing a dead band so that after the strain exceeds the preset amplitude and an electrical signal is produced the strain must decrease below the dead band and then increase again before another electrical signal is produced; and

means associated with each of said level detector means for counting said electrical signals whereby the count on each of said counting means is the number of times the strain exceeds the preset amplitude in the corresponding level detector means.

2. An electronic strain level counter according to claim 1 wherein said means for producing an electrical signal each time the amplitudes of one of the electrical pulses indicative of strain exceeds said preset amplitude and for providing a dead band is a D-type flip-flop with means for adding the output of the flip-flop to said preset amplitude.