Improvements in and connected with Dental Chairs.
Year: 1898

page_text: Date of Application, 23rd Feb., 1898-Accepted, 10th Dec, 1893
Improvements in and connected with Dental Chairs.
I, AXEL BOGREN, of Malmö, Sweden, Dentist, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:-
This invention relates to improvements in and connected with dental chairs
and has for its object to provide a back cushion whereby a jet of water in tempera-
ture as may be required and a coherent current of air can be produced auto-
matically for the purpose of washing and drying the cavities of teeth and the
like, which cushion consists of a frame, within which bladders or the like are
employed adapted to be depressed by the patient leaning against it and thereby
force a current of air into a heated reservoir containing water, the pressure of
which air forces a jet of water through a pipe or the said current of air through
the instrument of the operator.
And in order that my invention may be more fully understood I have caused
to be appended hereunto one sheet of drawings marked with letters of reference.
indicating like parts in the various figures, Fig. 1 being a back view, Figs. 2 & 3
vertical sections and Fig. 4 a horizontal section of my improved cushion.
a is a frame of wood or other suitable material vertically divided into three
spaces open at the back and closed in front, the outer spaces by the covers a¹ of
sheet metal, paste-board, wood or the like and the inner one by the spring cover b
or the like.
The front of the said frame and the covers are furnished with padding b' which
together with the cover form an elastic back cushion. In the middle space a
pair of bellows c, or an india rubber bladder, are employed provided with a valve d
for the entrance of air, safety valves and on its side with a passage e having a
valve which prevents the current of air returning to the bellows c.
This pas
sage terminates at a cock f from which are branching two pipes g and h
communicating with the bladders & formed of a thin elastic material, which
contract as the air within is expelled. These bladders & k are each surrounded
by a reservoir & m of sheet iron or other suitable material arranged in the side
spaces which reservoirs communicate with the atmosphere through a pipen and
nozzle o, or instead of the reservoirs & m two bladders of india rubber, skin or
the like may be arranged outside of the bladders & k. By means of the cock f
communication with either of the bladders i, k can be cut off. At one of the upper
corners of the frame a is fastened an arm in which a tubular part q formed with
a water reservoir is adapted to slide up and down. The upper end of the
reservoir r diminishes and is provided with a globular cover s screwed on. The
tubular part has two rectangular bends above the supporting arm p the last
of which is vertical and communicates with the reservoir r. At the lower end of
the tubular part q is a heater or receptacle for coal adapted to heat the water in
the reservoir r or the latter may be heated electrically.
To prevent loss of heat the reservoir r and the tubular part q are insulated.
Through the horizontal part of q and the reservoir r runs a thin tube having
at the lower end the nozzle u and in its continuity the nozzle u¹ protruding through

page_text: the tubular part 9 and at its extremity in the globular cover s an india rubber
nozzle u or the like formed with a small hole..
Around this nozzle is an india rubber bladder fastened to the diminished
upper end of the reservoir r. From the cock f branches a pipe having also
a nozzle by which communication can be established between the bladders i, k
and the atmosphere and if connected with by an india rubber pipe or the like
and the interior of the reservoir r. The latter at its lower end is provided with
a nozzle and cock y through which the water is forced into the reservoir r, or it
may be poured into the reservoir r when the covers and bladder are removed.
z is a nozzle formed on the horizontal part of q. The tubular part g and the
reservoir communicate with each other, see dotted lines Fig. 3, and to the
nozzles u¹, z are attached india rubber pipes or the like the other ends of which
are fixed to the instruments used for operating in the mouth.
The patient when sitting in the chair and leaning against the cushion depresses
the latter in the middle which causes the air from the bladder c to flow into the
bladders i, k, which expand and contracting afterwards cause the air to flow
from the bladders & through the pipe into the globular bladder and by
pinching the pipe at the nozzle u¹, impinges on the surface of the water in the
reservoir r, whereby a jet of water in temperature as may be required is forced
through the nozzle and respective pipe to the operator's instrument; by pinch-
ing the latter pipe with the fingers instead of the other, a dry current of air may
be obtained which passes through the nozzle u¹ and the pipe a u¹ to the operator's
instrument.
By means of a nozzle specially adapted and fixed to the end of a pipe attached
to the nozzle o the saliva flowing from the mouth of the patient may also be
effectively removed by allowing the air from the bladders i & to escape through
the pipe and thereby cause the bladders i & k to contract which contraction
creates a suction in the reservoirs & m, the pipe o in connection therewith being
furnished with a check valve and the suction power regulated by the amount of
air allowed to escape.
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-
In dental chairs a back cushion adapted to hold a quantity of air and when
leaned against by the patient produce a current of air which passes to a reser-
voir containing water of a temperature as may be required, from which a jet of
water by air pressure is forced through a pipe to the instrument of the operator,
whilst when the flow of water in the said pipe is interrupted, the current of air
itself will pass to the said instrument, thus producing coherent a jet of water and
current of air automatically, for the purpose of washing and drying the cavities
of teeth and the like, all substantially as shown and described.
Dated this 22nd day of February 1898.
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicant.