Improvements in and relating to Dental Chairs.
Year: 1897

page_text: Date of Application, 2rd Sept., 1897-- Accepted, 9th Oct., 1897
COMPLETE SPECIFICATION.
Improvements in and relating to Dental Chairs.
I, FRANK RITTER, of 503 and 565 North St. Paul Street, Rochester, Monroe
County, State of New York, United States of America, Manufacturer, do hereby
declare the nature of this invention and in what manner the same is to be per-.
formed, to be particularly described and ascertained in and by the following
statement:
The invention relates to dental chairs and has for its object to increase their
stability, compactness, ease of operation and efficiency. The invention consists
in the construction hereinafter described and pointed out.
In the accompanying drawings
Figure 1 is a vertical section of a chair-base, pedestal and seat-elevating
mechanism;
Figure 2 is a section on line 2-2 of Fig. 1;
Figure 3 is a section on line 3-3 of Fig. 2;
Figure 4 is a partial plan of the seat frame and cross-bar;
Figures 5, 6 and 7 are sections on the lines 5-5, 6-6, and 7-7 respectively;
Figure 8 is a view of a detail.
Numeral 1 denotes the bottom, and 2 an approximately cylindrical body of
a chair-base, said parts of the base being fixed to each other by screws 3.
4 denotes a lower part of a chair pedestal. This pedestal section has a closed
bottom and serves as an oil holder. 5 is an extension fixed to part 4 by screws 6.
The base section 2 and the pedestal section 4 are fastened in fixed relation to
each other by a wedge-shaped block a operated by a foot bar 6 secured by a screw
to the top of a short rod c having a screw thread connection with the block. The
rod fits a socket in the end of the lever and is further fixed thereto by a transverse
pin d. In the walls of this socket on the underside are a series of slots e
oppositely situated to fit over the pin and thus connect the rod and bar. These
slots provide for different adjustments of the operating bar to compensate for
wear. f is a guide for the rod c. g is a projection fixed to the pedestal and it
also receives and guides the rod.
A slight movement of bar b raises or lowers the wedge-block either to tighten
or loosen the connection between the base and pedestal. When the wedge is
raised the shoulder h of the pedestal-projection is simultaneously forced down
upon the edge of the base.
Tis a movable extension of the pedestal. 8 is a movable tube fixed to the
cross-bar 9 of the seat frame. The tube 8 and movable pedestal-extension 7 are
elevated in usual manner by a pump and they are telescopically connected with
each other and with the fixed pedestal section and these movable parts are guarded
against independent lateral movements and against all binding action by rods 10
and 11. The rods are fixed in flanges or projections 12 and 13 formed on the
interior of the pedestal sections. The rods 10 each fit an opening in a flange or
projection 10 on the seat tube 8 and the foot of said tube is accurately guided
by the rods and held horizontally in fixed relation to the pedestal section 7.

page_text: The rods 11 in like manner fit suitable openings in the flanges or projections 11'
on the foot of the pedestal section 7 anil the foot of said section is guided by
the said rods. These rods also obviate the use of keys and key way heretofore
employed.
The seat tube is also guided and steadied by a frusto-conical split tube 14
which has a central opening receiving said tube. In the wall of the opening
is a lubricating packing 15. The construction is such that the plug can be
screwed up or down in its seat in the tube 7 to insure its fitting the seat tube
suitably. The plug can also be removed to permit the introduction of the foot
of the seat tube into the pedestal tube 7 in assembling the parts, or the seat tube
can be introduced from below without removing this plug.
16 denote sectional packing rings in the pedestal section and 18 are screws for
setting them up against tube 7.
..
19 indicates a spring seated in a flange 10 and between it and a flange 12 to
prevent jar when the seat ascends.
20 denotes a foot lever fixed to a short rod 21 by a pin 22. Said rod has
bearings in the wings or projections 23 of the pedestal and constitutes the fulcrum
of the pump lever. 24 is the short member of the lever having parallel arms 24¹
and 25 is a screw for fixing a sleeve 211 of said lever member to the rod 21. The
lever is pivoted to the piston rod of a pump by means of a short rod 26. Returning
springs. are denoted by 27. These are attached to the ends of rod 26 and to the
fixed pedestal section."
28 denotes a projection upon the lever to arrest the same and stop the turning
action of the springs whenever said projection engages the part 281 of the
pedestal.
29 is a detachable cover fitting an opening 30 in the pedestal wall and held
thereto by screws 31. The upper part of the cover or door 29 engages a flange
or rib 32 at the top of the opening 30. This opening provides for inspection
and repairs within the pedestal and reservoir. The cover excludes dust and
maintains the symmetry of the pedestal. The fulcrum of the lever extends
outside the pedestal and fits bearings therein closely to avoid entrance of dust.
33 denotes a fixed piston tube. In order to provide space for the pump and
other parts without enlarging the base and reservoir laterally and without inter-
fering with the descent of the pedestal extension 7 the wall of said extension is
inset at 34 and said inset portion cut off at its bottom as shown at 35. This
permits the foot of tube 7 to drop below the main part of the pump cylinder
though the latter is situated partly within the circumference of the upper part of
the tube. The cutting away of the inset at 35 provides that when the tubes are
assembled the inset will not prevent turning the tubes and their flanges so that the
openings in the latter may register.
The seat is raised by pumping oil into the tubes as usual. 36 denotes a valve
which is opened to permit the oil to return to the reservoir and lower the seat.
37 are oil outlets and 38 is an oil escape passage whereby oil flows to the reservoir
when the valve is raised. 39 is a valve-stem guide. 40 is a spring normally
closing the valve and 41 a spring-compressing lever. 42 is a movable plug or
piston held loosely on the lever 41 by the spring. 43 is a screw plug to adjust
the tension of the spring.
To enable the seat to be adjusted horizontally with respect to its support the
seat tube 8 is fastened to the cross bar by a nut 44 screwing upon the tube and
forcing the shoulder 45 and bar toward each other whereby the bar is held between
said nut and shoulder until the nut is loosened whereupon the seat frame can be
independently rotated.
46 indicates the platform extension of the seat frame and 47 is a child's foot
rest folded back in inoperative situation in a recess 48.
One of the main objects of the invention is to provide that the above described
telescoping parts shall move smoothly and without wobbling or binding. For
this a plurality of guide rods constructed and arranged as specified is very,

page_text: efficient. Three rods for each movable part arranged circumferentially as shown
are very suitable though the improvement is not limited to the particular number.
As the movable sections descend at times into the oil holder they and their
connections are thereby constantly lubricated.
The accessibility and detachability of the various parts are desirable, and novel
features of construction are employed.
The space occupied and the danger of breaking in transportation is thereby
diminished as also is the cost of repairs. The accessibility of the pump and its
operating devices is a practically important feature. The described construction
whereby these and other advantages are secured are hereinafter pointed out and
the best forms and arrangements known to me have been set forth but variations
that involve simple mechanical skill and that have the same principles of
construction and operation are not excluded.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In a dental chair the combination of telescoping tubes, guide rods fixed
between the tubes and tube flanges provided with openings to receive and fit the
rods, whereby the tubes are guided and steadied and whereby independent rotation
is obviated, substantially as described.
2. In a dental chair the combination of telescoping tubes, guide rods fixed
to flanges in the movable and fixed pedestal sections and situated interiorly thereof
and exterior tube flanges provided with openings to receive and fit the rods,
substantially as described.
3. In combination with the elevating mechanism, the telescoping tube 7 having
an exterior flange 11 and an interior flange 12, a guide rod, fixed in one of the
flanges, and a guide rod movable through the other, substantially as described.
4. In a dental chair the combination of telescoping tubes having flanges and
guide rods and a spring situated between the flanges to prevent jar, substantially
as described.
5. In a dental chair the combination of the oil tank, the telescoping pedestal
sections and the guide rods, said rods and sections being adapted to be lubricated
by descent into the tank, substantially as described.
6. In a dental chair the combination of the base, the pedestal rotatably sup-
ported on said base, the wedge-block situated between the pedestal and base,
and block-moving devices to crowd said block against their walls, substantially
as described.
7. In a dental chair the combination of the base, the pedestal rotatably sup-
ported on said base, the edge-block situated between thd pedestal and base,
and block-moving devices to crowd said block against their walls, said devices
consisting of a screw, a detachable screw turning bar and means for adjusting
the bar with respect to the screw, substantially as described.
8. In a dental chair, a pedestal having an opening or doorway and a cover or
door to close the same substantially as described.
9. In a dental chair a pedestal having an opening or doorway and a cover_or
door 29 said cover being detachably secured to the pedestal and engaging under
a rib 32 thereof, substantially as described.
10. In a dental chair the combination of an oil holder, a pedestal section
adapted to be moved into the holder, a piston tube 33, and a pump, said pedestal
section having an inset part 34 to permit it to descend beside the pump,
substantially as described.
11. In a dental chair the combination of an oil holder, a pedestal section
adapted to be moved into the holder, a piston tube 33, and a pump, said pedestal
section having an inset part 34 to permit it to descend beside the pump,
tube 7 having flanges 12, the tube 8 having flanges 10', said inset being cut away

page_text: at 35 to permit the tube 8 to be rotated within tube 7 to cause said flanges to
register in assembling the parts, substantially as described.
12. In a dental chair the combination of the pedestal, the pump, the lever-
member 20 fixed to the fulcrum 21 at the exterior of the pedestal, said fulcrum
consisting of a rod pivoted in the pedestal wall, the short lever-member consisting
of a sleeve secured to the rod and provided with arms, a second rod extending
through said arms, a piston-connecting-rod loosely joined to the said second
named rod, and returning springs attached to the latter rod outside its bearings
in the arms, substantially as described.
13. In a dental chair the combination of a pedestal having a door opening, a
lever having its fulcrum situated in the opening and bearing in the pedestal
wall, lever-returning springs and a projection 28 arranged to engage the pedestal
and arrest the action of the springs substantially as described.
14. In a dental chair the combination of the telescoping pedestal sections and
the sectional ring 16 provided with screws for setting the ring against the inner
pedestal section, substantially as described.
15. In a dental chair the combination of the seat tube, the pedestal and the
frusto-conical split plug to adjust the bearing connection of said tube and pedestal,
substantially as described.
16. In a dental chair the combination of the cross-bar of the seat frame, the
seat tube provided with a shoulder, and a nut engaging the tube above the
shoulder to fasten the bar on the tube, substantially as described.
Dated this Third day of September 1897
CHARLES JUNGE,
Agent for the Applicant.