Electronic instrument for locating and diagnosing engine sounds

• US 5,445,026 A
• Filed: 06/14/1993
• Issued: 08/29/1995
• Est. Priority Date: 06/14/1993
• Status: Expired due to Term

• Current Assignee: Chris S. Eagan
• Original Assignee: Chris S. Eagan
• Inventors: Eagan, Chris S.
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): Oda, Christine K.
• Application Number:
  US08/075,790
• Time in Patent Office: 806 Days
• Field of Search: 73/591, 73/457, 73/40.5 A, 73/660, 73/661, 73/587, 181/131, 381/58, 381/67
• US Class Current: 73/591
• CPC Class Codes: G01H 3/12 by electric means G01H3/14 takes precedence
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00
• CPC Class Codes: G01N 29/223 Supports, positioning or alignment in fixed situation mounting transducers per se G10K11/004

Abstract

An acoustic signal and sound diagnostic instrument, for use by a professional automotive engine or industrial machinery maintenance operator, which is capable of locating and discriminating automotive engine and industrial machinery abnormalities. The instrument includes an acoustic transducer microphone, located at the forward end of an elongated deformable, semi-rigid probe arm, for detecting and converting acoustic signals and sounds into electromagnetic signals and an electronics housing conformed to be held in the hand of the maintenance operator with the housing mechanically supporting the probe arm at its rearward end. Pre-amplifier circuitry within the housing is electrically coupled to the transducer microphone and to range selector circuitry for selecting sound level ranges respecting the electromagnetic signals. A decibel meter, mounted to the exterior of the housing, is electrically interconnected to the pre-amplifier for visually indicating changes and peaks in the sound levels detected by the transducer microphone. Operational audio amplifier circuitry within the housing is electrically interconnected to the pre-amplifier circuitry for converting the electromagnetic signals into secondary acoustic signals that may be listened to by the operator through an earphone headset electrically interconnected to the audio amplifier. The instrument is energized by a battery power supply contained within the housing.

Claims

1. An acoustic signal and sound diagnostic instrument for discriminating audible automotive engine and industrial machinery abnormalities for use by a professional maintenance operator comprising:

a) an elongated deformable, semi-rigid probe arm bearing an acoustic transducer microphone at the forward end thereof for detecting and converting audible acoustic signals and sounds having a frequency in the range of from about 500 to about 10,000 Hz into electromagnetic signals;

b) an electronics housing conformed to be held in the hand of said maintenance operator, said housing mechanically connected to and supporting said probe arm at the rearward end thereof;

c) pre-amplifier circuitry within said housing electrically coupled to said transducer microphone for receiving said electromagnetic signals from said microphone;

d) range selector circuitry within said housing for selecting sound level ranges respecting said electromagnetic signals;

e) a decibel meter mounted to the exterior of said housing and electrically interconnected to said pre-amplifier circuitry for visually indicating changes and peaks in the sound levels detected by said transducer microphone;

f) operational audio amplifier circuitry within said housing electrically interconnected to said pre-amplifier circuitry for converting said electromagnetic signals into secondary audible acoustic signals;

g) a battery power supply electrically interconnected to said range selector circuitry and said pre-amplifier circuitry for energizing said instrument; and

h) an earphone headset electrically interconnected to said audio amplifier circuitry for use by said operator whereby said secondary audible acoustic signals are available to said operator for audible discrimination of engine and machinery abnormalities.

2. The acoustic signal and sound diagnostic instrument as claimed in claim 1 wherein the pre-amplifier circuitry has associated therewith a weighting curve selector with a "C" curve select position providing substantially uniform sound levels over the frequency range of from 32 to 10,000 Hz and with an "A" curve select position providing maximum sensitivity of human ear response to frequencies in the 500 to 10,000 Hz range.

3. The acoustic and sound diagnostic instrument as claimed in claim 1 wherein the decibel meter has electrically associated therewith a response selector switch having a first slow position whereby said meter is damped and indicates an average-value of the sound levels detected by said transducer microphone and a second position whereby said meter reacts quickly to a change in the sound levels detected by said transducer microphone and indicates peak sound levels in the environment of said microphone.

4. The acoustic and sound diagnostic instrument as claimed in claim 1 wherein the range selector circuitry interconnected to said pre-amplifier circuitry includes a rotatable control switch having an "off" position for terminating operation of the instrument, a battery "on" and check position for operation of the instrument, and a multiplicity of center-point decibel value range setting positions.

5. The acoustic and sound diagnostic instrument as claimed in claim 4 wherein the center-point decibel value range setting positions of the rotatable control switch of the range selector circuitry are 120, 110, 100, 90, 80, 70 and 60 decibels.

6. The acoustic sound diagnostic instrument as claimed in claim 1 wherein the pre-amplifier circuitry electrically interconnected to the operational audio amplifier circuitry includes access means for interconnecting a recorder-player device for recording the sound patterns and sound levels picked up by said transducer microphone.

7. An acoustic signal and sound diagnostic instrument for use by professional automotive engine and industrial machinery maintenance operators for locating and discriminating audible automotive engine and industrial machinery abnormalities comprising:

a) an elongated deformable, semi-rigid probe arm bearing an acoustic transducer microphone at the forward end thereof for detecting and converting audible acoustic signals and sounds having a frequency in the range of from about 500 to about 10,000 Hz into electromagnetic signals;

b) an electronics housing conformed to be held in the hand of said maintenance operator, said housing mechanically connected to and supporting said probe arm at the rearward end thereof;

c) pre-amplifier circuitry within said housing and electrically interconnected via leads extending through said probe arm to said transducer microphone for receiving said electromagnetic signals from said microphone;

d) range selector circuitry within said housing electrically interconnected to said pre-amplifier circuitry and operable by a rotatable control switch having a thumb operated selector dial mounted to the outside of said housing, said rotatable control switch of the range selector circuitry having an "off" position for terminating operation of the instrument, a battery "on" and check position for indicating operation of the instrument, and a multiplicity of center-point decibel value range setting positions;

e) a decibel meter mounted to the exterior of said housing and electrically interconnected to said pre-amplifier circuitry for visually indicating changes and peaks in the sound levels detected by said transducer microphone;

f) operational audio amplifier circuitry within said housing electrically interconnected to said pre-amplifier circuitry for converting said electromagnetic signals into secondary audible acoustic signals;

g) a battery power supply electrically interconnected to said range selector circuitry and said pre-amplifier circuitry for energizing said instrument when the rotatable control switch of said range selector circuitry is turned to said battery "on" position; and

h) an earphone headset electrically interconnected to said audio amplifier circuitry for use by the operators of said instrument for audible discrimination of engine and machinery abnormalities,

8. The acoustical signal and sound diagnostic instrument as claimed in claim 7 wherein the rotatable control switch of the range selector circuitry includes center-point decibel value range setting positions of 120, 110, 100, 90, 80, 70 and 60 decibels.

9. The acoustical signal and sound diagnostic instrument as claimed in claim 7 wherein the pre-amplifier circuitry has electrically interconnected therewith a weighting curve selector with a "C" curve select position providing substantially uniform sound levels to said operational audio amplifier circuitry over the frequency range of from 32 to 10,000 Hz and with an "A" curve select position providing maximum sensitivity of human ear response to frequencies in the 500 to 10,000 Hz range.

10. The acoustic signal and sound diagnostic instrument as claimed in claim 7 wherein the pre-amplifier circuitry electrically interconnected to the operational audio amplifier circuitry includes access means for interconnecting a recorder-player device for recording the sound patterns and sound levels picked up by said transducer microphone.

11. The acoustic signal and sound diagnostic instrument as claimed in claim 7 wherein the operational audio amplifier circuitry is provided with volume control means.