MEASUREMENT OF SPEED OF ROTATION BY SONIC AND ULTRASONIC FREQUENCIES SPECTRUM

• US 3,815,426 A
• Filed: 08/07/1972
• Issued: 06/11/1974
• Est. Priority Date: 08/17/1971
• Status: Expired due to Term

• Current Assignee: Dieter Rohner
• Original Assignee: Dieter Rohner
• Inventors: Rohner, Dieter
• Primary Examiner(s): Gill, James J.
• Application Number:
  US05/278,586
• Time in Patent Office: 673 Days
• Field of Search: 73/488,518,506,67,70.2,69 181/.5NP 324/166
• US Class Current: 73/488
• CPC Class Codes: G01P 3/48 by measuring frequency of generated current or voltage in general G01R23/00

Abstract

Apparatus and process wherein the center frequency of the narrow-band level peak of the sonic and ultrasonic spectrum produced by the false-twisting machine, which is directly proportional to the rotational speed of the spindles, is used for rotational speed measurement on false-twist spindles.

Claims

1. A method for contactless, substantially absolute rotational speed measurement of a false-twist spindle, which comprises picking up by an ultrasonic directional microphone the sonic and ultrasonic vibration spectrum produced by the spindle of a falsetwisting machine, filtering the picked up signals by a filter with a sonic and ultrasonic band width and converting the center frequency of the narrow-band level peak of said filtered band width within a frequency range of about 5 to 50 kc/s, which center frequency is directly proportional to the rotational speed of the spindle, into speed of rotation measurement units.

2. A method as claimed in claim 1, wherein the isolated signals are counted electronically, and the rotational speed of the spindles is converted electronically directly into digitally indicated revolutions per minute.

3. Apparatus for contactless, substantially absolute rotational speed measurement of a false-twist spindle which comprises an ultrasonic directional microphone for picking up the sonic and ultrasonic spectrum of a false-twist machine, and means for converting the signals picked up by the microphone into digitally indicated speed of rotation measurement units, said means embodying in series connection a filter with a band width of 5 to 50 kc/s, an amplifier, a Schmitt trigger with treshold value adjustment means, a gate circuit, a counting circuit and a digital indicating circuit, the gate circuit having operatively associated with it in series connection a quartz-controlled time-base generator, an impulse shaper and a count-down circuit, said Schmitt trigger modifying the picked up signals, the signals so modified passing through said gate circuit, and said time base generator controlling the opening of the gate.