Improvements in or in connection with Speaking Tubes.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in or in connection with Speaking Tubes.
I, WILLIAM HORACE Ross, of the City of Camden, in the County of Camden,
State of New Jersey, United States of America, Engineer, 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 generally to speaking tubes, and specifically to a new and
improved construction of mouth piece for the same, provided with a self-adjusting
call or alarm whistle, and has for its object cheapness and durability of construction,
simplicity in operation, and adaptation to either fixed or movable speaking tubes;
the provision of ready means for obtaining access to the interior thereof for
cleansing, means for insuring a free or comparatively free, passage-way for an
applied air current to sound a call or alarm, and finally, of obviating the employ-
ment of springs or the like for adjusting the whistle into or out of action, and to the
end sought consists in the novel features of construction, combination and operation
of parts shown in the drawings, and hereinafter particularly described and
claimed.
In the drawings:
Figure 1 is a front view of a mouth piece embodying my invention, and showing
the whistle in its normally inactive position, it being an inclined position relative to
its chamber and when in such position, partially uncovers, so to speak, the passage-
way to the tube whereby an applied air current may be caused to pass to and
through the tube to sound a call or alarm at the far end of the tube where a similar
whistle is located.
Figure 2. is a side view of the entire mouth piece.
Figure 3 is a sectional view of the mouth piece taken on the line y-y Figure 1,
and Figure 4 is a similar view of the mouth-piece showing the whistle seated in a
vertical position to the front of its chamber as when sounding a call or alarm, the
mouth-pieces in Figures 3 and 4 being represented as connected by a tube,-
shown in dotted lines, and the arrows indicating the direction of the applied air
current.
Figure 5 is a front view of the mouth-piece taken on the line y-y Figure 4.
Figure 6 is a modified view of the mouth-piece shown in Figure 3, and represents
the forced vertical position of the whistle to the rear of its chamber, when an
excessive air pressure is applied through the near mouth-piece to the tube for the
purpose of sounding a call or alarm at the far mouth-piece, and showing the whistle
provided on one side with prongs or projections, which abut against the rear wall or
inner shoulder of the chamber of the mouth-piece preventing the blocking of the
passage to the tube, and insuring space about the whistle for the passing of an
applied air current to the tube, and
Figure 7 is a perspective view of the whistle, shown in Figure 6, removed from
its chamber.
Referring to the drawings:
A is the mouth-piece, and a the mouth-piece proper, the latter being preferably a
metal casting of oval or bell mouth form having an exteriorly threaded neck a¹
provided with a central orifice or passage-way a*.
B is the call whistle of the common and well known type employed in mouth-
pieces of speaking tubes, and 6x Figures 6 and 7 are prongs or projections thereon
extending at right angles therefrom.
C is the chamber, it being preferably a cylindrical shell of metal screw tapped
interiorly at one end to receive the screw threaded neck al of the mouth-piece

page_text: proper, and at its opposite end is provided with an annular flange (which acts as
a wall plate when the mouth-piece is employed in connection with a fixed speaking
tube. This chamber is further provided with a neck or extension Cx which is
exteriorly screw threaded for effecting connection with a speaking tube, and is
joined to or cast integral therewith, and has a central passage-way in open com-
munication with the chamber.
D represents a speaking tube.
The diameter of the chamber C is of size slightly in excess of the whistle B,
and the latter is of size slightly in excess of the diameter of the passage-ways a*
and c, and is located within said chamber free of any attachment thereto.
When the whistle is at rest, or out of action within its chamber, it takes the
inclined position relative to its chamber as shown in Figures 1 and 3, a portion of
the passage-way c to the tube being then uncovered or exposed, this also is its self-
adjusted position when a current of air is applied from the front of its mouth-piece,
and permits the free passing of said air-current to and through the tube to sound a
call or alarm by means of a similar whistle located at the far end of the tube. The
relative size of the whistle and the interior length of the chamber is such as to permit
of the whistle assuming a prescribed inclined position within the chamber sufficient
only to partially uncover the passage-way c to the tube to allow of the passing of an
applied air current as and for the purpose recited.
In order to obviate the blocking of the passage to the tube by reason of excessive
air pressure applied through the near mouth-piece proper causing the whistle to
assume a forced vertical position to the rear of its chamber, I have provided the
whistle on one side with prongs or projections 6x (Figures 6 and 7) which abut
against the rear wall or inner shoulder c² of the chamber, and hold it off therefrom,
sufficiently far to effectually prevent the blocking of the passage-way c to the tube
and allow ample space about the whistle for the escape or passing of the air current
to the tube for the purpose intended.
When an applied air current is oppositely directed through the tube, it lifts the
whistle out of its normally inactive inclined position, and seats it in a vertical position
to the front of its chamber next the passage-way a* and closes said passage-way,
and, as will be understood, the air current then finds its outlet through the hole in
the whistle simultaneously sounding a call or alarm, all as indicated by the combined
Figures 3 and 4, and the whistle resumes its normally inactive inclined position
upon the ceasing of said applied air current.
The mouth-piece proper a being removable easy insertion or removal of the
whistle is permitted, and convenient access had to the interior of the chamber for
cleansing.
I do not wish to be understood as restricting myself to the exact construction of
parts shown in my drawings, but may vary the same in any manner to cheapen its
construction, or to better carry out the principle of my invention without departing
from the true scope thereof, which consists in constructing a mouth-piece for
speaking tubes with a suitable chamber provided with a whistle free of any attach-
ment thereto, and self-adjusting in the manner described.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :
1. A mouth-piece for speaking tubes consisting of a suitable chamber provided
with a mouth-piece proper at one end, and at its other end with suitable means for
connecting with a speaking tube, a whistle located in said chamber and free of any
attachment thereto, the whole constructed, arranged and adapted to operate, as and
for the purposes set forth.
2. In combination with a speaking tube, a mouth-piece consisting of a suitable
chamber provided with a mouth-piece proper and a whistle located in said chamber
free of any attachment thereto, and self-adjusting as described, and for the purposes
set forth.

page_text: 3. In mouth-pieces for speaking tubes of the character herein described, a valve
or whistle located therein free of any attachment thereto, and provided on one side
with prongs or projections, as and for the purpose set forth.
Dated this Eighth day of November 1890
WILLIAM HORACE ROSS.