Improvements in Binaural Stethoscopes.
Year: 1893

page_text: Date of Application, 6th Nov., 1893-Accepted, 9th Dec., 1893
COMPLETE SPECIFICATION.
Improvements in Binaural Stethoscopes.
I, ARTHUR FREDERICK LAMBERT of 44 Mayfield Road, Dalston, in the County
of Middlesex, Surgical Instrument Manufacturer, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
My invention relates to an improved device for holding and then locking the ear
tubes or arms (hereinafter called arins) of a binaural stethoscope in their adjusted
position in the ears of the user of the instrument.
Hitherto springs or bars and a set screw have been largely used for the purpose,
but both these devices are characterised by certain drawbacks.
The present invention consists in the combination with the arms of a bar and
loop fast to the arms respectively, or a pair of bars fast to the arms respectively
and a loop fast on one of the bars, the engagement of the bar, or of one of the
bars, in the loop, constituting, in either case, the holding device, and the jamming
of the edges of the said bar and loop effecting the locking of the said arms in their
said adjusted position. The bar or bars project from the respective arm or arms in
the direction of the other arm as heretofore.
In order that my invention and the best means of carrying it into practical effect
may be thoroughly understood, I will now describe it and them in detail, referring
in so doing to the accompanying figures which are to be taken as part of this
Specification and read therewith.
Figure 1 is a plan of a stethoscope made according to my invention with a pair
of bars and a loop and in the adjusted position.
Figure 2 is a plan of the same instrument after the two tubes have been discon-
nected and reconnected side by side, ready for being slipped into the pocket or
put away.
Figure 3 is an elevation of Figure 2.
a, a are the two arms. b, b' are a pair of bars, preferably, of the same length.
Each is made fast to its arm a and stands out therefrom in the direction of the other
when the two arms are in the position which they occupy during the use of the
instrument, one bar to the side of the other, and both long enough to overlap for
the greater portion of their length. c is a loop made fast on one of the bars—say
the bar b. The cavity of the loop is parallel with the bar to which it is fast and
aligned with the other of them. It is of importance that the loop be not too long,
and that there be a little play between it and the bar which enters it. If it is too
long, it and the last mentioned bar would only slide smoothly past each other, and
the above mentioned jamming would hardly be practicable.
The invention is used as follows. The end of the bar b-the one without a
loop is inserted in the loop c, the ear pieces inserted and adjusted in the ears, and
the bottom ends of the arms pressed together. Seeing that this pressing together
takes place below the bars and loop, the edges of the bar without the loop are
jammed against two of the edges of the latter, with the result that the arms are
locked in the adjusted position in the ears of the user of the instrument.
The bars b, b and loop c are shewn as arc-shaped to a centre somewhere in
the direction of the funnel d, but I do not limit myself in this respect, for they may
be of any suitable shape, but I prefer the one illustrated because the necessary
movement of the ear pieces towards each other is effected by a correspondingly
small motion of bar and loop.
It is to be distinctly understood that I claim as included within the scope of my
invention, any modified form of the holding and locking device which I have
illustrated, provided that such modified form provides for each arm being held to

page_text: the other, for one half of the device to slide in or upon the other and for there
being sufficient play between the two halves for their being locked together. For
instance, one of the bars may be dispensed with and the loop be fixed on the opposite
arm. Or instead of a flat bar or bars and loop, a bar or bars and loop, or its
equivalent, of any other section, may be used.
Having now particularly described and ascertained the nature of my said inveu-
tion and in what. manner the same is to be performed, I declare that what I
claim is :-
1. The combination with the arms of a binaural stethoscope, of a sliding device
adapted to hold and then lock the arms together in their adjusted position in the
ears of the user of the instrument, as set forth.
2. The combination with the arms of a binaural stethoscope, of a pair of bars
respectively fast to the said arms and a loop or its equivalent adapted to receive
one of the said bars, by which each arm can be held to the other one and both
locked together in their adjusted position in the ears of the user of the instrument,
as set forth.
3. The combination with the arms of a binaural stethoscope, of a bar and loop
respectively fast to the said arms, the bar adapted to slide through the loop, by
which each arm can be held to the other one and both locked together in their
adjusted position in the ears of the user of the instrument, as set forth.
Dated this 6th day of November 1893.
PHILLIPS & LEIGH,
22, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.