Two-way stethoscope for direct and amplified sound

Claim 1

A two-way stethoscope, for use selectively with direct and amplified transmission of sound comprising: (i) a hollow generally cylindrical contactor body having an end wall with a plurality of sound pickup holes therein, and having an inner cylindrical wall with a plurality of communication holes therein; (ii) a hollow cylindrical turn tube having a plurality of communiction holes therein, said turn tube being engaged within said inner cylindrical wall of said contactor body; (iii) a sound tube having two ends, said tube being connected at one end to said turn tube and communicating with the interior thereof; (iv) at least one earphone provided at the other end of said sound tube, said earphone being hollow and including an electromagnet and a diaphragm; (v) a microphone means, for transforming sound entering through said pickup holes into electric signals, arranged in the hollow space of said contactor body; (vi) an amplifying means connected to said microphone means; (vii) an electric current source for said amplifying means; (viii) a conducting lead integral with said sound tube, said lead connecting at one end to said amplifying means and at the other end to said earphone, and (ix) a switching means for interrupting the current flow between said current source and said amplifying means, said switching means consisting of a first switch contact mounted on said turn tube and a second switch contact mounted on said contactor body, said first and second contacts being positioned so as not to be in contact with each other when the turn tube is in a position of rotation with respect to the contactor body in which the communication holes of the turn tube coincide with the communication holes of the contactor body, said contacts being adapted to contact each other in another position of relative rotation in which the respective communication holes do not coincide.