US257487A - Stethoscope - Google Patents

Description

(No Model.,- W. F. FORD.

' STBTHOSGOPE. I No. 257,487 Patented May 9,1882.

f, near its periphery.

UNITED STATES PATENT Orrrce.

WILLIAM F. FORD, OF NEW YORK, N. Y.

STETHOSCOPE.

SPECIFICATION forming part of Letters Patent No. 257,487, dated May 9, 1882.

Application filed April 4, 1882.

(No model.)

To all. whom it may concern:

Be it known that I, WILLIAM F. Form, residing at NewYork, in the county of New York and State ofNew York, have invented certain new and useful Improvements in Stethoscopes, ofwhich the following is a specification, refer ence being had therein to the accompanying drawings.

My invention relates to a spring connecting the two arms or ear-tubes of a stethoscope and governing the pressure exerted by the ear-tips in the ears of the examiner.

Heretofore the governing-spring has been made of an elastic or spiral wire spring passing between the ear-tubes above and across the hinge-joint. The breath of the examiner causing a vibration of the elastic or spi *a-l wire has given rise to false sounds, which, transmitted by means of the tubes to the ears of the examiner and mingling with the sounds emanating from the chest of the patient, caused a confusion otsounds, which detracted from the value of the instrument as a means of diagnosis. To obviate this difficulty is the object of my invention; and to this end theinvention consists in a coiled spring inclosed in a casing made in two parts, each part being carried by an arm extendingt'rom one of the tubes, whereby a concealed and noiseless spring is obtained.

In the accompanying drawings, Figure 1 is a. view of an instrument known as Oannnans stethoscope. Figs. 2, 3, 4, and 5 are detail views.

A is the nozzle which is placed against the chest of the patient, and B B the tubes extending therefrom to the ears of the examiner.

From each tube an arm, (I, extends inward toward the other tube and slightly inclined toward the nozzle. At the end of each arm is a circular shallow box,1'), somewhat resembling one-half of a case for inclosing a watch-spring. One box is provided with a central fixed post, 6, and the other box is provided with a stud, One end of a coiled spring, G, is attached to the post 6, and the other end is attached to the stud f. The two boxes are placed together to form a close casl l l l ing, and are secured by a nut, H, fitting on the screw-threaded end of the post 0, which projects through a central hole in its opposite box in a similar manner to that adopted for securing the case of a pocket measuring-line; or, in lieu thereof, a screw,K, maybe passed through the post and engaged with the nut, as shown in Fig. 4.

On the periphery of each box B are two shoulders, I m, located less than one hundred and eighty degrees apart, so as to allow an axial play of a few degrees, but to limit said play.

he operation is as follows: When the instrument is not in use the two shoulders H are together. When it is to be used the tubes '3 B are moved outward suliiciently to allow their ends to be inserted in the cars of the ex aminer, during which motion the arms 0 (J move upward toward a sti aight line with each other a number of degrees equal to the number of degrees traversed by the tubes and until arrested by the shoulders m m coming together. The ends of the tubes are then placed in the ears, and the tendency of the spring (I to expand pulls the tubes toward each othe and holds them in place with sutiicient pressure. to cause their ends to lit closely in the ears of the examiner.

\Vhat I claim as new, Letters Patent, is-

l. The combination, with a stethoscope, of a concealed noiseless spring inclosed in a easing made in two parts and connected with the tubes of the instrument, substantially as and for the purpose herein described.

2. The combination, with the tubes B B,-of the arms O, the boxes 1) I), having shoulders I m, post 0, and stud f, and the coiled spring (l, substantially as and for the purpose herein described.

In testimony whereof I aflix my signature in presence of two witnesses.

\VILLIAM F. FORD.

and desire to secure by Witnesses:

FRANCIS CLARE Bowen, A. J AMES LASKE.

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