Displacement measuring apparatus

• US 4,914,609 A
• Filed: 07/25/1988
• Issued: 04/03/1990
• Est. Priority Date: 07/30/1987
• Status: Expired due to Term

• Current Assignee: Nitto Kohki Company Limited
• Original Assignee: Man Design Company Limited
• Inventors: Shimizu, Giichiro, Wakatsuki, Yoshio, Okuyama, Toshiharu
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/223,356
• Time in Patent Office: 617 Days
• Field of Search: 364/560, 364/561, 364/570, 364/571.01, 364/571.06, 33/503-505, 73/1 J, 377/17
• US Class Current: 702/158
• CPC Class Codes: G01B 7/00 Measuring arrangements characterised by the use of electric or magnetic techniques
• CPC Class Codes: G01D 5/248 by varying pulse repetition frequency

Abstract

An oscillator outputs an oscillator frequency corresponding to a moving distance of a probe. A counter counts the oscillator frequency of the oscillator. A computer calculates the moving distance. A display unit displays the moving distance computed by the computer. A voltage booster and a voltage stabilizing circuit are connected between the oscillator and a battery. The driving voltage from the battery is supplied to the oscillator through the voltage booster and the voltage stabilizing circuit, and is supplied to the counter, computer and the display unit without passing through the voltage booster and the voltage stabilizing circuit in order to reduce the power dissipation.

Claims

1. A displacement measuring apparatus comprising:

probe means brought into contact with an object to be measured;

oscillating means including a core member coupled to said probe means and a coil wound around said core member, said oscillating means outputting an oscillation frequency corresponding to a moving distance of said probe means when said core member is moved in said coil in response to a movement of said probe means;

counting means, coupled to said oscillating means, for counting the number of cycles of said oscillating means and for outputting a count signal representing the oscillation frequency;

arithmetic control means, coupled to said counting means, for computing the moving distance of said probe means based on a count from said counting means;

display means, coupled to said arithmetic control means, for displaying the moving distance computed by said arithmetic control means;

battery means for outputting a drive voltage;

voltage stabilizing means, coupled between said battery means and said oscillating means, for stabilizing the drive voltage output from said battery means, and for applying a predetermined stable voltage to said oscillating means; and

means, coupled to said battery means and said counting means, arithmetic control means, and display means, for directly applying the drive voltage from said battery means to said counting means, said arithmetic control means, and said display means.