USRE11931E - Dental chair - Google Patents

Description

Reissuad Sept. l7, v 190|.

F. RITTER.

DENTAL CHAIR.

(Application mnd Jun. D, 1901.)

4 Shasta-ul l.-.

l F. RITTER. DENTAL CHAIR.

(Appicaeiun med Ju. 9, 1901s,

No. ||,93I. Reissued Sxept. I7', I90I.

4 Sheets-Sheet 2.

YM 2 am ll'.lei-rrno STATES nenni; nrrrnn, on noonnsfrnn, NEW YORK.

PnrnNr` OFFICE.

DENTAL oHAm.

SPECIFICATION forming' part of Reissned Letters Patent No. 11,931, dated September. 17, 1901-.

Original No. 619,228, dated February 7, 1899. Application for reissue l January 9, 1801. Serial No. 4.2|74. I

Chairs, (heretofore patented to mein British Letters Patent dated September 3, 1897, and numbered 20,295 3) and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

The invention relates to dental chairs, and

has for its object to increase their stability,

compactness,ease of operatiou,and eiiiciency. The invention consists 'in the construction hereinafter described and pointed out.

In the accompanying drawings, Figure l is'` a vertical section of` a chair-base, pedestal, and seat-elevating mechanism. Fig. 2 is a section on line 2 2 of Fig. 1. Fig. 3 is a seetion on line 3 3 of Fig. 2. Fig. 4 is a partial plan of the seat-frame and cross-bar. Figs. 5, 6, and 7 are sections on the lines 5 5, 6 6, and 7 7, respectively, of Fig. 1. Fig. 8 is a plan of a bar for operating a locking device, and Fig. 9is a partial section of said bar and locking device.

Numeral l. denotes the bottom, and 2 an approximately cylindrical body, of a chair-base,

said parts of the base being,lr fixed to each other by screws 3.

4 denotes a lower part of a chair-pedestal. This pedestal-section has an extension pendent within the base-body and havinga closed bottom, which downward extension serves as an oil-holder. 5 is an extension fixed to part 4 vby screws 6. The pedestal has an exterior an-l nular projection g, whereby it rests rotatably on the base, and the baseand pedestal may at will be fastened iu fixed relation to each other by a wedge-shaped block @operated by a lever b, secured by escrow to the top of a short rod o, having a screw-thread connection with the block a. The rod, fits a socket in the end of the 'lever and is further fixed thereto by a transverse pin d. Iuthe walls o! this socket on the under side are a series of slots e, oppositely situated to fit over the pin, and thus connectthe rod and bar. These slots provide for diierent adjustments of the lever to compensate for wear.

fis a guide for the rod c, and. said rod is also guided by the projection q.

A slight movement of lever 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 ofthe pedestal projection is simultaneously forced down upon the edge of the base.

7 is a tube movable lengthwise the pedestal.

8 is a. movable tube fixed to the cross-bar 9 of lhe seat-frame. When the chair-seat descends to its lowest position, the foot of said tube 8 and also the foot of tube '7' are moved down Within an oil-holder and adjacent a pump, to be described. Y Y

The tubes 8 and 7are elevated in the usual manner' by a pump, and they are telescopically connected with each other, andthe latter is telescopically connected withthe pedestal extension 5, and these movable parts are guarded against independent lateral movements and against all binding action by rods l0 and 1l. The rods are fixed in flanges or projections l2 and 13, formed on the tube and pedestal, as shown. The rods4 10 each the tube 8, and the foot of said tube is accurately guided by the rods and held horizontally in fixed relation to the tube 7. These rods obviate the use of keys and keyways heretofore employed. The rods ll in like manner 'fit suitable openings in the anges or projections 11' on the foot of the tube 7, and the foot of said tube is guided by the said rods. At the foot of tube 7 is a pendent spring 7', adapted to obviate jar when said tube reaches the bottom of the reservoir. The said tube 8 is alsol guided and steadied by a frusta-conical split plug 14, which hasa 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 tube 8 suitably, andy and regulate the friction.

' to the rod 2l.'

out removing this plug.

16 denotes a packing-ring comprising three separate sections movably held in a recess formed inthe inside of the pedestal extension 5, and 18 denotes screws for setting the ring-sections up against tube 7. These 'can be manipulated to nicely center the bearing separately adj ustable.`

19 indicates a spring seated in a flange l0' and between it and a fiang'e12 to prevent jar when the seat ascends.

20 denotes a foot-lever xed to a short rod 2l by pin 22. Said rod has bearings in the wings or projections 23 of the pedestal,which Wings constitute the fulcruln of the pumplever. 21 is the short member of the lever, having parallel arms 24:', and 25 is a screw for fixing aV sleeve 2l of said lever member The lever supports in its arms 24" a rod 26, to which at its middle pointA is loosely connected the upper end of pistonrod 26' of a pump. Returningsprings are denoted by 27. These are attached' to the ends of rod 26 and to the fixed pedestal-sec tion. A

28 denotes a projectionv upon the lever to arrest the saine and stop the returning action of the springs Whenever said projection engages the part 28' of the pedestal.

1 the stop 28 is indicated es held against said partby' the action of the springe.

29 is a detachable cover fitting an opening 30 in the pedcstal-wall and held thereto by screws'l.

l provide spacejfor the pump and other parts without enlarging the base and reservoir laterally and without interfering with the descent of the tube 7, the Wall of said tube 'is inset at 3l and said inset portion cut oii at its bottom, as shown at This' permits the foot of tube 7 to drop below the main part of the pump-cylinder, though'the latter is situated partly witliinthe circumference of the upper part of the tube. The inset part of vtube 7 is cutaway at 35, as shown in Figs. l

and 2. This leaves au opening in the foot of the tube adjacent ,door 30 and provides that when the tubes are assembled the inset will not prevent turning the tubes and their Ilanges, so that the openings in the latter may register.

' The scat is raised by. pumping oil into the Each section is' In Fig.

The upper part of the cover'or door 29 engages a flange or rib 32 at the top tubes, as usual. A pump provided with suitable valves and piston and a pistonrod 26' are indicated in Fig. 1.

56 denotes a valve which is opened to permit the oil to return to the reservoir and lower the scat.

37 denotes oil-outlets, and 38 is an oil-escape passage, whereby the oil flows to the reserf voir when the valve is raised.

39 is a valve-stem guide. n 40 is a spring normally closingthe valve, and 41 a spring-cornpressing lever.

2Vis a movable plug or piston held looscl on the lever 41 by the spring.

43 is a screw-plug to adjust the tension of the spring. i

To enable the seat Ato be adjusted horizonv tally with respect, to its support, the tube 8 is fastened to the crossbar by a natali screwing upon the tube and forcing thesaid bar and a shoulder 45 on the tube toward each other, whereby the bar is held between said nut and shoulder until the nut'is loosened,y

whereupon the seat-frame can b e'independcntly rotated.

As it is desirable that the seat be aslow'as possible with respect to the elevating devices, the cross-bar Ais situated in the plane of the seat-frame and is recessed to receivesaid nut 44,'whichn use does not extend above the bar nor interfere with the seat. The plungerrod bears'upon the under side of the nut',-

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each. movable part arranged circumferem. f

tiaily, as shown, are very suitable, though the improvement is not limited to the particular number. As the movable'sections do'-l seend at times into the oil-holder, they and their connections are thereby constantly lubricated.

The accessibility and detaeiiability of the various parts are desirable,and novel features of construction are employed. The space occupiedand the danger of breaking in transportation are thereby diminished, as also is the cost of repairs.

The accessibility of the pump audits operating devices is a practi- -v cally important feature. The described construction whereby these and other advantages are secured are hereinafter pointed. out., and the best forms and arrangements known to nie have been set forth; but Variations that involve simple mechanical skill and that havev the same principles of construction and operation are not excluded.

` 4. Iam aware that a fixed plungertube has been; closed at', the top by a cap having its top perforated'for the passage of a plunger-rod and that a so-called combined nu'tf and swodge has been,proposed forl use with a coupling' for tubular rails, the purpose and elect being to produce a fixed connection of a coupling and rail. Said nutand wedge was providedmith a screw-threaded portion and lo a hegdandl theY threaded portion provided witl'nkerfsV extending directly across a part of the threads, the head and upper screw- 'threaded portion being circumferentially inl Such devices are not of my inven- 1$tionfwhich comprises a frusto-conical plug ."Bplit" through its entire length, as required forlthe'pu'rpzles of my improvement, which 'contemplates a uniform bearing of the plug upon the tube embraced by it and a conseze' quent uniformity of wear throughout its en-` 4 tire length and; acapacity for nicety of ad- I. Ina dental chair, a supporting-basan pedestal, a plurality of rotatable telescoping "tnbeigjone of said telescoping tubes carrying on it'sfinterior a guide-rod fixed at both ends 'nearl its inner surface, another tube carrying .on itslexterior a projection movably vfitting 'saidrrodpsubstantially as described. 2. In combination with seat-elevatiu g mech- 'nis'm, the fixed base, the rotatable pedestal' .having xed thereina guide-.rod 11, a tele- ,scopingY tube 7 movably connected to said rod andoarrying on its interior av -rod 10, and a telescoping tube 8 movably connected with said rod 10, said tube 7 having at its foot an interior liange to hold its'rod and an exterior .nge to embrace thepedestal-rod, substantally as described. V3i In combination with the seat and tube elevatingand lowering mechanisma base,

. the telescoping tubes, flanges 12 within the' exterior tube, a guide-rod xed to the said anges,a flange 10 on the exterior of the inner telescoping tube, said rod being freely movable through the flange, and a sprin g situated between flange 10' and one of the flanges 12, substantially as described.

4. 'In combination with the tube and seat elevating and lowering mechanisln, a base, lthe telescoping tube 8, the telescoping tube 7 having anges 12 at its top and bottom and a flangell at its bottom, the rotatable pedestal,-a guide-rod fixed in the pedestal, said described my invention, what I- base to draw said wedge-block between the walls of the pedestal and base and directly against them and also comprising a lrod having a screw-thread connection with the wedge and a connection with the bar, said devices and block being supported on and movable with the pedestal, substantially as described. 6. In a dental chair, the combination of the bse, the pedestal rotatably supported on said b se, the .wedge-block situated between the -pedestal and base, anddevices to draw said wedge-block between the walls of said pedestal and base, said devices and the block being` supported onand movable with the pedestal, the block-moving devices comprising a screw, a detachable screw-turning footbar and means for adjusting the bar with respect to the screw to compensate for wear, substantially'as described.

7. In a dental chair, the combination Aof a pedestal comprising an oil-holder, a tube l8, a tube 7, both tubes being adapted to be moved into the holder, a pistolrtube 33, and a pump situated adjacent the path of said tube 8, said tube 7 having an inset part 34 to permit it to ldescend into theoil-holder between the pump and said tube 8, substantially as described;

8. In a-dental chair, the telescoping tubes 7 and 8, said tube 8 having a iiange 10 and the tube 7 having flange 12 and the inset 34 cut away at 35, whereby in assembling the parts, the tube 8 after its iiange has been moved to a plane above the interior iiange at the foot of tube 7 can be rotated to cause the holes in the iianges to'register, substantially as described.

9. In a dental chair, the combination of the pedestal, thepump, the lever having members 20 and 24 the member 20 being fixed as at 22, exteriorly of the pedestal, to the rod 2l, the said rod pivoted in the pedestal-wall, the short lever member 24 consisting vof a sleeve secured to the said rod and provided with arms, a second rod 26 extending through said arms at their outer ends, a piston-rod 26 loosely joined to'said rod 26, and returning-springs attached to the latter rod and to the pedestal, substantially as described.

10. In a dental chair, the combination of a pump, a pedestal having a door-opening, a reservoir, a pump-operating lever having a member situated in the opening and provided with bearin gs fixed to the pedestal-wall, leverreturning springs, and Va projection 28 arranged on the rotating part of the lever to engage the part 28' of the pedestal and arrest ..the action'of the springs, substantially as described. 1

11. In a dental chair the combination of a seat, a base, telescoping parts to guide the seat, and a truste-conical split plug, bearing.

to guide the seat, a frusto-conical split plug,

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1o the tube, and the nui; being situated in salia to regulatete friction and t@ compensate fm Wear, one of'said teesooping parts nm/'ing a fi'usto-conical seat copeming with the plug.

13. In a dental chair, che combination ofy the cross-bar ot' the seat-milie, the tube E5 provided with shoulder 45, a mit engaging the tubo above the shoulder t0 fasten tha bar on the tube, said bar having a. enes .about iii@ mit, substantaily as described.

in testimony whereof I have Signad this yspeiicaigion in the presence of two subscribing witnesses.

' FRANK RTTER.

Witnesses:

WM. LYNN, CARROLL A. THOMPSON.

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