US1340299A - Motor-stethoscope - Google Patents

Description

0. SMILEY. MOTOR STETHOSCOPE.

APPLICATION FILED MAY 24; 1919.

31,340,299. Patented May 18,1920.

M M INVENTOR 9 ATTORNEY UNITED srnrns PATENT onrion OR'VALL SMILEY, OF INDIANAPGLIS, INDIANA.

MOTOR-STETHOSCOPE.

Application filed May 24, 1919.

To alt whom it may concern:

Be it known that I, ORVALL SiriLnY, citizen of the United States of America, and a resident of Indianapolis, in the county of h-Zlarion and State of Indiana, have invented certain new and useful Improvements in Motor-Stethoscopes, of which the following is a specification.

This invention relates to improvements in stethoscopes and is especially intended for locating abnormal Working conditions in mechanical devices, particularly automobile engines. The object of the invention 1s to provide a construction by means of which sounds entering the receiver will become amplified therein so as to enable the operator to distinguish with greater certainty between the normal and abnormal noises of machinery and to more readily locate the sources of abnormal sounds. Another object is to provide means within the receiver which will tend to render inaudible reactionary sounds therein.

The objects of the invention are accomplished by the construction illustrated in the accompanying drawings in which Figure l is an elevation of a stethoscope receiver embodying the present invention, the view being partly cut away and in central section; and

Fig. 2 is a plan view of the amplifier, shown partially cut away.

Similar characters of reference indicate corresponding parts in both views and referring now to the same:

1 is a metallic shell of tapering form which is closed at its large end by a cap 2, the latter having tubular projections 3 extending therefrom for the attachment of flexible tubes 4 which are intended for connection with a head-piece (not shown) of the usual type for connection to the operators ears. The small end of the shell is open for the reception of sound waves, and

within the shell is arranged a.hollow wooden frustum 5, the ends 6 and 7 01 which constitute diaphragms that differ in the extent of their respective diameters. The annular tapering wall 8 of the frustum secured be tween the heads 6 and 7 has approximately the same slant as the shell 1, and is set in slightly from the perimeters of the heads so that its external surface is held from contact with the internal surface of the shell, there being an annular space 9 between the wall and the shell. The wall and heads of the Specification of Letters Patent.

Patented May 18, 1920.

Serial No. 299,524.

I thereof in the immediate vicinity of the part to be examined. The sound waves emanating from that vicinity where the receiver is thus applied enters its open end and effects directly the primary diaphragm 6, causing it to vibrate in conformity to the sound waves. The secondary diaphragm is effect ed indirectly by the sound waves so that it is caused to vibrate also therewith. The vibratory movements of the primary diaphragm 6 are imparted to the secondary diaphragm 7 through the medium of the annular wall 8, and'the secondary diaphragm is also sympathetically effected with vibrations emanating from the primary diaphragm through internal sound waves that set up within the frustum because of the vibration of the primary diaphragm. -lhrough the vibratory action of the secondary diaphragm sound waves set up within the cavity 10 in the large closed end of the receiver and these are observed by the operator through the tubes in the customary manner. Because of the annular space 9 between the wall 8 and the shell, the wall actuates freely and also serves to exclude from the interior of the frustum any reactionary sound waves that may be reflected from the interior surface of the shell.

lVhat I claim is 1. In an appliance of the class described, a tapering shell, open at its small end for the reception of sound-waves, and closed at its large end, there being tubular extensions for the passage of sound waves from the interior of the large end; and a hollow frustum, the heads of which are adapted to vibrate as diaphragms, the annular tapering wall of the frustum being set in slightly from the perimeters of the respective heads so that the external surface of the wall is held from contact with the internal surface of the shell.

2. In a stethoscope receiver, a metallic shell of tapering form, the small end of which is open for the reception of sound waves; and an amplifier having two diaphraq ms spaced apart and an annular tapering wall connecting the two diaphragms, said amplifier being positioned within the tapering portion of the shell.

3. In a stethoscope receiver, a shell having an open end for the reception of sound waves and a sound cavity within its opposite end, a primary diaphragm extending transversely within the shell near its open end; a secondary diaphragm of greater diameter than that of the former diaphragm and extending in parallel relation therewith, said diaphragms being spaced apart; and means supported at its ends by the corresponding diaphragms for imparting vibrating movement from the primary to the secondary diaphragm.

4. In a stethoscope receiver having a shell with an opening therein for the reception oi sound waves, two diaphragms of different diameters spaced apart and supported by the shell upon the interior thereof in parallel relation with each other; a thin annular wall supported at its ends respectively by said diaphragms, there being an annular space between the exterior surface of the cavity and an opening for the reception of sound waves, a hollow wooden frustum posi tioned in the receiver between its sound-cavity and the opening, the heads of the frustuzn being adapted to vibrate as diaphragm. In testimony whereof I afiix my signature in presence of two witnesses.

ORVALL SMILEY.

Vitnesses: ALICE FINNEY, LULU W. Wrsems.

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