US2840432A - Safety device for dental units - Google Patents

Description

June 24, 1958 N. E LAUTERBACH 2,840,432

SAFETY DEVICE FOR DENTAL UNITS Filed 001'.. 20, `1955 A 3 Sheets-Sheet l IN VEN TOR. NORMA/V E. LAU T E REACH BY E T June 24, 1958 N'. E. LAUTERBACH SAFETY DEVICE EoR DENTAL UNITS 5 Sheets-Sheet 2 Filed Oct. 20, 1955 INVENTOR. NORMAN E LUTERBCH Arron/5r June 24, 1958 N. E. LAUTERBAcl-l 2,840,432

l SAFETY DEVICE FOR DENTAL UNITS Filed oct. zo, 1955 s sheets-sheet s JNVENTOR. NORMA/VE LAUTERBAOH VDL. K

United ,States N Pater-1f i 2,840,432 SAFETY DEVICE F R DENTAL UNITS Norman E. Lauterbach, Pittsford, N. Y., assignor to Ritter Company, Inc., Rochester, N. Y., av corporation of Delaware v 'f v Application october zo, 19ss,se1riali-10.541,642l 6 claims. (cl. S12-209) This invention relates to an equipment stand and more specifically to stands of the type comprising "a unitary column or pedestal for supportinga variety of dental, medical and like equipment within convenient reach of the user adjacent the place of use. Reference is made to Patent No. 2,690,945 issued October 5, 1954 to FayV is again actuated to retract the equipment withinnthe equipment stand and close the door toy protect the instruments from dust and possible damage when in an exposed position.v Notwithstanding the fact that initiation of the operation of the motor is by a switch within the convenient reach of the dentist, it has been Yfound in practice that a dentist will occasionally inadvertently or carelessly endeavor to open or force the door manually to enable access to the instruments. Moreover, it has been found in practice that occasionally one of the instruments may not be fully retracted within the instrument holder when the dentist presses the switch to close the door and the instrument or its cord may be caught between the edge of the door and the margin of the opening in the equipment stand which the door closes. In the mechanism of that patent the connection between the motor and the instrumentvholder is such that when this occurs the `mechanism will become jammed and bent or the motor shaft will be snapped oil. I vAn yobject of my invention is to overcome th'e diiliculties above set forth with the structure shown in the-Bronk patent when the equipment is carelessly operated.

Another object of my invention is to provide in the linkage between the motor and the door and instrument holder, a connection which is automatically broken when an attempt is .made to manually force open said door or when an objectbecomes caught between the edge of the door andthe margins of the opening which the'door closes. l

More specifically, my invention contemplates thefemployment of a novel toggle construction in the mechanism of the above mentioned patent which will break when an undue strain is placed upon the mechanism or the motor is overloaded due to careless or inadvertent operation of the mechanism.

Other objects and advantages be pointed out in the claims and will be apparent from the following description, when taken in connection with the accompanying drawings, in which:

Fig. l is a view showing the interior of the equipment stand in which the instruments are normally housed,l

showing the instrument holder retracted and the door in' its closed position, the view showing onlysuch portionv yof my invention willy ofthe equipment stand with which the invention is concerned;

Fig. 2 is: a view similar to Fig. 1 with the holder and the instruments, in their projected position and with the door open; f t

Fig. 3 isv a view the connections between the motor and the instrument holder and door are broken Y less use of the equipment;

VFig. 4 is a top plan View oflva part of the linkage shown in Figs.; l to `3inc1usive and showing the'toggle link whichs ffbroken when an `attempt is made to force the door open manually;

Fig. 5 Vis asectional -viewv taken substantially on thev line 5-5 of Fig. 4 in the direction indicatedV by the arr0W;f

Fig. 6 is a view showing aportion of the linkage and in particular the toggle link of Figs. 4 and 5, the view showing the parts in the position which they occupy when the door is` closed and the instrument holder retracted;

Fig. `7 is a view similar to Fig. 6, the links being shown in theposition which they occupy when the dooris open and thejinstruments-projected; e Y

Fig. 8 is a view similar to Figs. 6 and 7 but showing the position ofthe parts when the toggle has been broken,

, the view corresponding to the position of the parts shown arm and its' associated table and other appurtenances' common in the art. AllV of the elements Vdisclosed in this application andtheiroperation will not be described in detail, reference to the abovementioned patent being had for that purpose.V

' Referring toFigs. 1 and 2, the equipment stand com prises a housing 11 having an opening `12, and a holder 13 having sockets for the reception of a plurality of dental or medical instruments 14. The stand includes a door 16 and a plurality of retractable cords or cables 17 which enable the individual instruments 14 to be pulled out of their holder and -be automatically retracted into the holder when released as is common practice in the art.

The holder 13`is supported for movement to project it forwardly through the opening 12 as will be apparent from comparison of Figs. l and 2, opposite sides of the holder having trunnions 18 serving to pivotally connect the holder between spaced arms 19 which are bridged through a portion of their extent by a panel 21. The panel carries certain controls not necessary to describe herein and when the instruments are in extended position as shown in Fig. 2, the panel closes the opening above the holder.

The Side walls of the panel 21 have their upper ends extended to provide spaced'arms 22 whichV are pivoted on studs or trunnions 23 which are supported internally of the equipment stand. Arms 22 are extended beyond their pivots 23 to form fingers 24 each having its end connected to a counterbalance spring 26. A second set of springs 27.is connected between the ends of the fingers 24 and The door iciscarried'by a pair of spaced` arms 34 2,840,432 Patented June k24, 19,58 n

showing the position of the parts whendue to incorrect or careupstandingelements ,31 torminsg; ,av carnigroove 38 in which a roller 39' rides. These' rollers 39 are rotatably supported'- in bracketscarrjed by thearms 2r9,

' The .mechanism .described fis actuatedgby a' motoridiagrammatically illustrated at 41. 0n the endY ofthernotor shaft an actuating Aelementr42 isprovided having VJthree arms 43, 44 and 46.1Two ofthese ,arms 43' and 444 actuateV micro-switchesjwhileffthethird arnr 46 serves as Aa crank arm. 'Reference-is made' to theabove mentioned patentrfor a disclosure of the motor fircuitlandits'asso ciatedipalts;itbeingsncient to state herein 'that a manual switch locatedwithin convenientgreachof thedentistcon trois the automaticrswitches to initiate-movement' of theY parts from` one position Vto`anotherbthatffis from the'posi'- tion shownsinFigfl; to }that shwninf1-`ig, 2 or `reverse. Uponeach actuatifniofr the manual switchVVV the -actuator 42 rotates through 180`degrees. The circuit and switches are varranged so? that Lupon ractuation-'of the manual switch and u.the -completion of Y l-8O 'degrees of rotational operation,V

motor operation Yis,y discontinued. crank arrntKY-is connected bytoggle'link-means,y generallydndicated by the numeral V47, to the Vpanel 21 as shown atr48. "'The detailsv rofthis toggle linkggmeans constituteddhe irnprovement of my invention'rand Zha'sybeen shown 4to-9 inclusive; s v It is believedtthat 4the'loperation of the -mee'hanism'from the foregoing description;r particularly'upon; reference Vto the vabove mentioned Apatent will be understood. WinniV the partsaare intheypositionshown in-Fig. 21, abr'ief closure ofthe manual switch serves to startthe motorand close the automatic switch until the partsreaeh=the` pro` jectedA position 4of use shown in Fig. 2 lat which timelfthe operation -of :the motor vbrings .about the "opening of=the circuit and arrests the-movement of the parts. Suchoperation first-swingsthe-.covenor door to atleast a partially or Vdentist `standing orse'ated .fomthe opposite sidenofa dental chairinwhich ar patient .is seated. Afteruseof the instruments carried :by' .the fholder, a .second voperation `.of the manual switch retracts the, instrument holder:and lcon. trol panel .andcompletely closes the ,housing :opening to v protect the lparts, exclude .dustand maintain the.

motor shaft. `A similar result rnayroccur if the dentistV has an instrument in `an Vextended position `with respect to the holder and `releases .the instrument for retraction:

into the holder while at the same time pressing y.the-manual switch. The instrument may .then be between the upper edge. of the door'and vthe .margin of the opening which it closes, that is, adjacent the point S1 (Figi).

Due tothe inadvertenee orcarelessness .of dentists in operation of their equipment, it has been .found desirable or necessaryto' provide means for protecting the equip. ment should it beimproperly operated. Y Such meansrcomf. prises the toggle iink means 47 .shown 4in Fig`s.4 vto 9Y inelusive..`

As shown most .cl'early zin Figs. @tand `5:.the .toggle link. means: 47.".c`omprisesran arm S2. The arm. 52 has .ax

bottonrwall 53 and a pair. of upstanding .sidewalls v54'.

A pivot rod :.56 constituting the pivot 48 (see Figs. Land` 2) extends through the .sidewalls 54. A pivot pint57" extendsethrough the sidewallsat the opposite end of lthe arm 52.` The sidewalls 54 are notched as shown at 58 to accommodate a pin V59 mounted on the end of the actuating arm 46. The pin 59 is adapted to pivotally receive a toggle link 61 which lies between the sidewalls 54 of the arm 52 and is pivoted on the pin 57. A spring 62 somewhat S shaped having one end secured to the toggle link, as shown at Y63, `isV confined by a pin 464 extending between the sidewalls 54. The spring retains the toggle link 61 in the position shown in'Fig. 5. Adjusting means, shown at 6 6, determines the .position .to 'which .the spring .62 will urgefthe .toggle 1ink\61. lBy threading `inward or outward on the adjusting means 66 theetect-of the spring 62 may be `decreased .or increased. Upon threading the adjusting means inward, the toggle inay be broken more easily.

ln Fig. 5 I have drawnV two lines A and B. Line A extends through the pin 64 and pivot 57. It will be noted. that the point 63 of attachment of thespring-to the tQggle link lies `he'low .this line. Thus the .spring retains 'the toggle link '51' below a' dead center position represented by the line A. The 'line B extends through the center of the pivot rod 56 and through the pi'votpin 57. The center of the Apin 59 liesslightly above this '.line

I B.V Thus the force of the motor, rotating thevactuating' .open position: andswin gs@the holder and panel ftd-the' advanced position shown -in` Fig. 2 in l which 'position 4the instruments projected within easyrneachof the operatorarm 46, tends to break the ltoggle while the force of the spring j62"overcomes the -force o'f the motor vand retains the'toggle Vin the position' shown in Fig. 5 unless 'the motor becomes overloaded by reason, for example, ofan instrument or other object being caught between Vthe upper edge ofthe door Aand the margin of thedooropen'- ing." Such overloading of the motor 'will' cause an up-Y ward"force on the pin 59A and break the toggle."

In fFig's flfhave shown the 4parts of the togglelirik means 4T-and Iits `associated parts in the position which they occupy-when the door 'is closed as will be :evident from a comparison of Figs. 'l and 6. Likewise lIfhave' shown the Vposition of the parts in Fig. 7 when 4the door is open which will be evident 'from a comparison ofFigs; 2 and 7. lIn sFig. v8 I ha-Veshown the ltoggle broken. In this position -of the parts 'the load on the motor duejto` jamming A.of the Amechanism `has caused 'the force -exerted by theMrnotor` on the pin 159 to overcome'the Aspring 62j and` .brealr 4the toggle. The rigid connection' between the actuator 4146i and vthe panel' Z1 :is then 4`tlestreyed'tci` thereby prevent bending-of the links or 'thersnapping of the 4motor-shaft. When ythe toggle hasbeen brolten, as illustrated inFig. 38, due Ito the 'lack efr-a lrigid con` neet-ion. between, the parts, ithe door and the instrument holderimay'drop :to `the position shown in 'Brand :anyy obstruction .may .bey removed. The entire mechanism Fist j ofmyinvention it '-.wll `be .apparent `thatuzarious v.modificaan electric motor and an instrument holder, means intercpnnectingsaid motor .and holder `for projecting the holder from a posi-tion withinthe equipment stand to an vexternalposition with respectt'hereto, means including a manually operated switch for initiating the operation of Vthe motor and a make and"brcak` toggle 'in said inter" connecting means for (protecting the motor should it become overloaded;` said toggle 'including [two elements pivoted to eaehother `one of which is connected to the t motor and the'otherof which is-connectcd .tothe holder,

a 'stopbetween said. members, a `spring for normallyholding1 one off said Vmembers against said stop and lin a .bel'` y'ond dead center position and means including said motor for throwing said member away from said stop and to the other side of the dead center position should the motor become overloaded.

2. Mechanism of the character described comprising, in combination, motor means, a crank arm driven by said motor means, a pivoted arm adapted to support and swing an object to be shifted from one position to another position upon one cycle of the motor means and returned to its original position upon a succeeding cycle of said motor means, link means pivoted to said arm and having connections to said crank arm which connections include a make and break toggle, said make and break toggle comprising a toggle link having a pin which pivotally connects the toggle link to the crank arm, a pivot between said toggle link and said'link means, a spring biasing said pin and toggle link into a position such that a driving connection is formed from the motor means to said pivoted arm through said link means during normal operation of the mechanism, the force of said motor means when overloaded overcoming the spring bias to break said driving connection which condition of motor means overload may be occasioned by a resistance to the free swinging movement of said arm.

3. Mechanism in accordance with claim 2 in which operation of the motor means is controlled by a switch which upon actuation initiates rotation of the motorv means which then rotates through 180 degrees after which the driving force of the motor is discontinued.

4. Mechanism in accordance with claim 2 in which the pivot connection of said link means and the'pivot connection of said toggle link to said link means form a 6 line andthe spring normally biases the toggle link to a position on'one side of `said line while the rotational force of the motor means tends to move the toggle link to the `other side of said line, the force of said spring being suicient to overcome the torque of the motor means under normal conditions of operation but insuflicient to `overcome the force of the spring should an overload be imposed upon the motor means.

5. Mechanism in accordance with claim 2 in which the pivot connection of said link means and the pivot connection of said toggle link to said link means form a line and the spring normally biases the toggle link to a position on one side of said line while the rotational force of the motor means tends to move the toggle link to the other side of said line, the force of said spring means being suicient to overcome the torque of the motor means under normal conditions of operation but being suicient tofovercome the force of the spring should an overload be imposed upon the motor means and means for adjusting the position to which said spring biases said toggle link on the rst mentioned side of said line.

6. Mechanism in accordance with claim 2 in which means are provided for making said toggle upon the next cycle of said motor means if the resistance to the free movement of said arm has been removed.

References Cited in the le of this patent UNITED STATES PATENTS 1,167,805 Elliott June 11, 1916 2,280,246 McCullough Apr. 21, 1942 2,690,945 Bl'onk Oct. 5, 1954

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