US2825135A - Self-contained abrasive applicator - Google Patents

Description

March 4, 1958 w. F. TILDEN SELF-CONTAINED ABRASIVE APPLICATOR Filed Jan. 10. 1956 I /2 \\N xx 1 m w a5. Y 8 W 9 e M I23- d/ 7- MT k 0 7 "H 9 w w n. w M 3 M 1 A N 4. 3 9 L J 8 a z 7 r M a 6 58 M A W v Y. 4 B

United States Patent SELF-CON TAINED ABRASIV E APPLICATOR William F. Tilden,San Francisco, Calif.

Application January 10, 1956, Serial No. 558,212

lo Clainis'. (CI. 32-58) The present inventionconstitutes anadvance over the abrasive applicator which. is disclosed and claimed in my co-pending application, SerialNo. 521,029, filed July 11, 1955, and entitled Abrasive Applicator. This application is. a continuation-in-part of the aforesaid co-pending application.

A primary object of my improvement is to provide a self-contained abrasive applicator possessing unique and more positive control'of the volume of abrasive emitted. from the applicator.

Another important object of the invention is to provide an applicator of the indicated nature which is additionally characterized by unique features to prevent packing of the abrasive in the. hopper thereby insuring free flow thereof to the delivery nozzle. 7 I

A still further object of my present inventionis to provide a self-contained abrasive applicator of'the aforementioned character which affords more facile replenishing of abrasive.

Other objects ofthe invention, together with some off the advantageous features thereof, will. appear from the following description of a preferred embodiment .of'the present improvementwhich is illustrated in the accompanying drawings. It is to be understood, however, that I am not to be limited to the preciseembodiment illustrated, nor tothe precise arrangement of the various parts thereof, as my invention, as defined in the appended claims, can be embodied in a plurality and variety of forms.

Referring to the drawings:

Fig. 1 is a longitudinal sectional view of a preferred embodiment oftheimprovement, some parts beingshown in fragmentaryv illustration for lack of space and one part being shown in elevation.

' i Fig. 2 is, an enlarged detail, partly in section, of the elements at the gas inlet end of the. hopper and.their association with'the gas dryer.

Fig. 3 is an enlargedsectional detail of elements surroundingthe abrasive carryingrigid tube to prevent return of, gas within the hopper.

In itspreferred form, the self-contained abrasive applicator of. my present, improvement preferably comprises a hopper forholdingavolume of a dental abrasive, a .pistonwithin saidhopper for maintaining a diminishing volume. of abrasive in said hopper under pressure; said hopper havingjan air ,inlet atoneendlthereof, an abrasive carrying rigidtube supported'in said hopper. in. axial align-. ment with .said'air inlet; said rigid tube having an annu-- lariport therein'adjacent to said air inlet'end of'saidlhopper, a hollo l t Valve projectinginto said tube and controlling said port; said valve regulating the quantity of abrasive,entering said'tube from said hopper through said port, meansior-causinga flow. of a stream ofdry air through said hollow jet valve and said rigid tube to effect the withdrawal of abrasive-fromsaid hopper and entrainment thereof in said air stream, together with a hollow hand-pieca a rigid tubing" supported in i saidhand-piece, a. flexible conduitiestablishing communication between said rigid-tube and" said rigid tubing, a nozzle 'on" said hand-piece in communication with said rigid tubing, and manually operable means for controlling the volume of abrasive-laden air emitted from said nozzle.

The principal elements of the present improvement, as illustrated in Fig. l of the annexed drawings, comprise'a handpiece'6, a hopper 7 for holding a volume of a powdered abrasive 8, means for supplying a gas under pressure, such as an air compressor not shown, a .gas drying apparatus 9, together with a plurality of elements hereinafter described for efiecting the emission of a controlled volume of abrasive-laden gas at desired locations, such as various teeth to be cleaned or ground for filling operations or other dental work.

As illustrated in Fig.1, the hand-piece 6 of my improved self-contained abrasive applicator. preferably comprises a rigid hollow elongated body 11, preferably fabricated from a light-weight metal or from a plastic material, which is closed at its inlet end by a removable apertured cap 12'and which is conveniently knurled, as at 13', on its outer surface for ready handling. At itsopposite or outlet end, the body 11.is provided withv a removable closure 14 having an end opening 16 therein for the passage of a nozzle holder 17 which carries at its outer end a nozzle tip 18;'the closure member 14 defining an interior chamber between the adjacent end 19 of the body. and the closure which conveniently is filled with felt packing 21'. The nozzle holder. 17 isported, asat 22, to permit the escape of'a small volume of filtered gas free of abrasive, which isvented through the felt packing 21 i to the atmosphere through opening 16 in the closure 14 thus aiding in the control.of.the flow of abrasive-laden gas from the nozzle tip 18 of the hand-piece. I Thehandpiece jinteriorly supports a rigid'tubing 26 by fittingthe same through, the aperture. of'cap 12 at the, inlet end of: the body and through the bore of a slidable member 27 as well as byfitting the; same into one end of a short rubber tubing 28. The rubber tubing 28v is extended through apassage 29' formed in a valve body 31- which is in screw-threaded engagement with the rigidbody 11- adjacent to the nozzle end of the hand-piece. .Nozzle In accordance with the present invention, I provide.

means on the hand-piece 6 for pinching therubber tubing 28 to any extentdesired thereby regulating the volume.

' of abrasive-laden. gas passing therethrough to the nozzle tip 18 whichis in communication with tubing 28 through nozzle holder 17. These means constitute, in eifect, a valve" for opening and closing tubing 28 and comprise apinching element or. depresser 32, preferably formedfto an angle-shape as shown, which is disposed in a.transverse bore 33 ofvalve body Stand which is inbearing engagement with a cam surface. 34' on the stemI36- of a finger-button 37;. The. button 37 is-slidably mountedon 'the hand-piece 6 bymeansof a rod 38. which is.

engaged by a' screw39 'extending'through the button 37 sothat flow therethrough is' completely shut oif. closed position of the valve, the finger-button 37 rests in its extreme position adjacent to the nozzle end of the handpiece. To open the valve thebutton 37 is moved toward the rear of the hand-piece and the slidable movement of the'button 37 is indicated by the double-arrow line 40..

The rearward'movement of finger-button 37 effects the rearward movement of the slidable member 27, through the'medium'of-"theconnectedrod38, againstthe action of a spring 41 which is confined within the body 11 between the cap 12 thereof and the slidable member 27 and which is compressed by the rearward movement of thebutton 37., Release of the finger from finger-button 37 effects a complete closing of the valve, or complete pinching of the flexible tubing 28, as shown in Fig. 1, by the action of spring .41 which moves slidable member 27 and rod 38, together with connected button 37, to their extreme positions to the left or adjacent to the nozzle end of the hand-piece 6. I thus have provided a positive control of flow of abrasiveladen gas to the nozzle tip 18.

A supply of a powdered dental abrasive 8 is maintained in the hopper 7 which preferably is formed with a body portion of cylindrical configuration the walls of which converge at one end to provide a relatively narrow neck 51 defining a relatively narrow passage, the walls of the passage being threaded, as at52, for threadedly receiving supporting elements for a jet nozzle hereinafter described. At the opposite end, the hopper is closed by a removable closure 54 which is seated, with an interposed rubber washer 56, on the rimof the hopper preferably by means of a bayonet clutch connection; the closure 54 being formed with an integral elongated hollow section 57, projecting normal thereto and centrally of closure 54 and a disc 63 which is removably mounted on the piston 59 by threaded engagement therewith and locked in position by means of a lock-nut 64; the disc 63 carrying an integral boss 66 about which the coil spring 61 11s coiled. The boss 66 of disc 63 is formed with a central bore 67 and serves as a guide and partial support for a rigid conduit 68 which extends through the hopper 7, through the bore 67 of boss 66 as well as through the hollow section 57 of closure ,54 to project through and beynd such section 57 into the hollow nipple 58 thereof; the conduit 68 terminating short of the neck 51 of the hopper and being provided at this end with an enlarged r scction 69 in which a transverse port 71 is formed for permitting passage of the abrasive powder 8 into the conduit.

A source of gas under pressure, such as an air compressor, not shown, is provided for delivering a stream of an under pressure to and through the rigid conduit 68. Since air delivered from an air compressor usually has considerable moisture therein, I preferably pass the air delivered from the compressor through a drying chamher which conveniently is defined by a housing 73 contaming a quantity of a dehydration substance 74, such as Silica Gel or the like, which effects the removal of substantially all moisture from the air passing through the chamber. The housing 73 is closed at one end and is provided with a removable cover 76 at its opposite end; the cover 76 preferably being formed with a short passage 77 therein which is enlarged at its inlet end to receive the nipple 78 of a flexible conduit 79 leading from the air compressor, not shown. Secured'to the bottom of the cover 76 of housing 73 and suspended therefrom within the chamber 74 is a narrow tube 81 which communicates with the air compressor throughthe inlet passage 77 in the cover 76. The cover 76 of housing 73 is formed with an integral annular boss'82 which is internally threaded for efiecting threaded engagement with the neck 51 of hopper 7, the neck 51 being exteriorly threaded for i an inclined threaded passage 92 into which a screw 93 is jet nozzle 86 for causing an air stream to flow under pressure through the rigid tube 68 of the hopper 7; the jet nozzle, in effect, serving as a needle valve for controlling the quantity of abrasive 8 that is withdrawn or aspirated from the hopper through port 71 for entrainment in the air stream moving through tube 68. The jet nozzle 86 is of sufficient length to project through the cover 76 of the housing 73 and into the compartment or chamber 74 thereof in order to pick up air delivered from the air compressor, not shown, through flexible hose 79 to the air chamber through the rigid tube 81 supported therein, As shown, the jet nozzle 86 conveniently is supported in operative positionbymeans ofan exteriorly threaded sleeve 87 and a threaded bushing 88 in which the jet nozzle is snugly fitted and held; the sleeve 87 and bushing 88 being threadedly connected into the neck 51 of the hopper 7 through the medium of internal threads 52 of the neck 51. As shown in the enlarged view of Fig. 2, the bushing 88 is recessed for receiving an O ring 89 and a longitudinally threaded bore is formed in the bushing for receiving a locking screw 91 which, upon being tightened, locks the bushing tightly about the jet nozzle and against the sleeve 87 to firmly hold the jet nozzle against displacement. The neck 51 of the hopper 7 is formed with loosely threaded; such passage 92 serving as a vent to the atmospherefor a small amount of air or gas that escapes from the rigid tube 68 through port 71 during the operation of the compressor. The sleeve 87 is formed with an inner annular flange 94 thereon which isin abut ting engagement normally .with the bottom of the hopper 7 to preventthe dropping of the sleeve through the air inlet end of the hopper, and a felt washer 96 is interposed between the fiange94 of the sleeve and the bottom of the hopper to filter out any abrasive powder tending to pass out through the vent 92 in the neck 51 of the hopper., By this arrangement of the above-described parts, jet nozzle 86 is always maintained co-axial with the rigid tube 68 of the hopper in order that even flow of abrasive-laden gas is attained. As illustrated, the tapered end of jet nozzle 86 defines. a relatively narrow orifice 97 which at all times is disposed'within the enlarged section 69 of the rigid tube 68 of the hopper despite the relative position of the orifice of the jet nozzle with respect to the port 71 of tube 68. With the aircompressor in operation, a venturi action occurs within the enlarged section 69 of the tube 68 and in all open positions of the jet nozzle or needle valve 86 a quantity, ofthe powdered abrasive 8 will be aspirated and withdrawn from the hopper for entrainment in the air stream flowing through the jet nozzle and associated tube 68. Adjustment of the needle valve or jet nozzle 86 with respect to the port 71 of the tube 68 is effected by slight turning of the hopper 7 with respect to the housing 73.

In order that pressures be equalized on each side of the piston 59 as the quantity of the powdered abrasive in the hopper 7 is gradually diminished, and to permit the piston to move freely under the influence of the spring 61 and not be adversely afiected by differences in air pressures, I 6

preferably provide a small bleeder port 98 in the tube 68 adjacent to its outlet end which allows the continuous escape of a small quantity of air between the sleeve 62 and the inner wall of the section 57 of the cover 54 of the hopper to fill the space in the hopper in back of the piston 59. The powdered abrasive in the escaping material from the bleeder port 98 is filtered out through a felt packing 99 which is disposed within a cup-like enlargement 101 of the sleeve 62 adjacent to the bleeder port 98. A suitable annular .bushing 102, recessed to receive an O ring 103, serves as a backing for the felt packing 99; the bushing being screw-threaded into position onthe bottom of the cup 101 and the O ring 103 serving to seal the joint against leakage of air or abrasive.

To complete the assembly, I provide a fiexibleconduit .96 i i dete n te length t es g ma i tion' between the rigid tube26 of the: hand-piece. 6 and the rigid tube 68 of the hopper; one end of the conduit; 106 being attached to the projecting end of the rigidtube 26 of the hand-piece and the other end of the conduit 106 being connectedto the projectingnipple, 58 of the hopper cover. With the flexible tubing 28 of the hand-piece 6 closed and with the air compressor in operation, a head of abrasive-laden gas is always available". for delivery, to the nozzle tip 18 and controlled amountsof the abrasiveladen gas will be emitted from the nozzle by manipulation or" the finger-piece 37 of the hand-piece.

The applicator of my present improvement is entirely portable and can readily be set up for connection to a small air compressor which is usually available in a dentists otfice. The drying chamber housing 73 can be of such a size as readily to fit in the space normally occupied by a medicine bottle in a conventional dental unit and in which heat is supplied to the bottle. Thus, the drying chamber 74 of my improved applicator can be kept warm and the air from the compressor warmed as it passes through the chamber. This feature is advantageous when treating sensitive teeth, i. e., sensitive to cold or thermal changes, and thus reduces tendency to pain.

By virtue of the construction of the hopper 7, replenishing of the powdered abrasive 8 therein is greatly facilitated. All that is required to be done, to fill the hopper, is to remove the closure 54 thereof and withdraw the piston 59 by grasping and pulling on the spring 61 which is anchored to the boss 66 of disc 63 which, in turn, is secured to the piston; and then pour a new supply of powdered abrasive through the thus opened top of the hopper and thereafter replace the removed parts. The sleeve 87 with its flanged extremity 94 is always in fixed relation to the hopper 7 and efiectually seals the hopper through the medium of felt washer 96 against the escape of abrasive through the passage of the neck 51 of the hopper. The spring-urged piston 59, having substantially equal pressure on both sides thereof, follows the diminishing supply of abrasive in close contact therewith at all' times.

It is to be understood that the appended claims are to be accorded a range of equivalents commensurate in scope with the advance made over the prior art.

I claim:

1. A self-contained abrasive applicator comprising a tubular hand-piece, a first rigid tube supported in said hand-piece, a flexible tubing in said hand-piece communicating with said rigid tube, a hopper, a quantity of abrasive powder in said hopper, a second rigid tube extending through said hopper; said second rigid tube including an enlarged section having a port therein, a jet nozzle coaxially supported within said second rigid tube; said nozzle including a tapered tip for covering and uncovering the port of said enlarged section of said second rigid tube, a gas drying chamber connected to said hopper for relative rotation; rotation of said hopper relative to said chamber effecting the movement of said port of said second rigid tube with relation to said tapered tip of said jet nozzle, a flexible hose establishing communication between said second rigid tube and said first rigid tube, an applicator nozzle mounted on said hand-piece in communication with said flexible tubing, means for causing a stream of gas under pressure to flow to and through said gas drying chamber to cause a stream of dry gas to flow through said jet nozzle thereby to aspirate a quantity of abrasive powder from said hopper through the port of said second rigid tube and to cause the delivery of a quantity of abrasive-laden gas to said applicator nozzle, and means movably mounted on said hand-piece for selectively pinching said flexible tubing to regulate the amount of abrasive-laden gas to said applicator nozzle.

2. A self-contained abrasive applicator comprising a hand-piece, a rigid tube supported within said handtrained in said stream may be regulated.

hopper, a gasdr-yingchamber rotatably'connected. to; said hopper andthroughwhich a gas under pressureis caused to flow, a rigid conduitsupported in' said hopper; said conduit having a port therein, a jet nozzle coaxially supported within said rigid conduit adjacent to the port therein for. uncovering and coveringsaid port in responseto rotation of said hopper relative to. said gas dryingchamber; said jet nozzle establishing communication between said gas drying chamber and saidrigid conduit of said hopper, and a flexiblehoseestablishing communication between said rigid conduit and said rigid tube of said hand-piece.

3. In an abrasive applicator, a hopper, a quantity of powdered abrasive in said hopper, a gas drying chamber rotatably connected to said hopper and through which a gas is caused to flow under pressure, a rigid tube supported in and extending through said hopper; said rigid tube including an enlarged section having a port therein communicating with the interior of said hopper, and a jet nozzle coaxially supported within said rigid tube adjacent to the port in the enlarged section thereof and extending into said gas drying chamber to establish communication between said chamber and said rigid tube and for conducting a stream of dry gas to the tip of said nozzle whereby powdered abrasive may be aspirated from said hopper and entrained in said stream; rotation of said hopper relative to said gas drying chamber effecting an adjustment of said jet nozzle relative to the port in the enlarged section of said rigid tube whereby the quantity of abrasive aspirated from said hopper and en- 4. In an abrasive applicator as defined in claim 3, including a piston in said hopper, and means urging said piston into engagement with a diminishing supply of abrasive in said hopper.

5. In an abrasive applicator as defined in claim 4; said rigid tube having a bleeder port therein adjacent the end thereof opposite to said enlarged section for equalizing pressures on opposite sides of said piston.

6. In an abrasive applicator as defined in claim 5, including a filter surrounding said port for preventing abrasive passing into said hopper on the spring side of said piston.

7. In an abrasive applicator, a hand-piece, a flexible tubing in said hand-piece through which an abrasiveladen gas is caused to flow, and means for selectively pinching said tubing for controlling flow therethrough; said means comprising a valve body removably fitted to said hand-piece adjacent said flexible tubing, said body having a transverse passage therein, a pinching element in said passage engaging said tubing, a valve stem in said body having a cam surface thereon engaging said pinching element; said valve stem being adapted to be manually shifted within said passage to move said cam surface over said pinching element to fully close said tubing by pinching the same with said pinching element and to open said tubing to any desired extent by relieving the pinching of said tubing.

8. In an abrasive applicator as defined in claim 7, including means for automatically returning said valve stem to an initial position with said flexible tubing fully closed upon release of manual pressure on said valve stem.

9. In an abrasive applicator as defined in claim 7, including a finger-button on said valve stem projecting outside of said hand-piece, a slidable member fitted within said hand-piece, a spring confined between an end of said hand-piece and said slidable member for urging said member toward said valve body, a rod extending through said valve body and said valve stem; said rod engaging said slidable member, and means connecting said fingerbutton and said rod whereby manual movement in one direction of said finger-button effects slidable movement of said member against the force of said spring and repiece, a hopper, a quantity of powdered abrasive in said lease of said finger-button effects a return of said member 7 and said'rod and said valve stem automatically to their initial positions in response to the action of said spring.

10. In an abrasive applicator, a hand-piece, a flexible tubing in said hand-piecethrough which an abrasiveladen gas is caused to flow, a nozzle holder supported on 5 said gas from said port insuring an even How of abrasiveladen gas through said nozzle holder to a point of application.

References Cited in the file of this patent UNITED STATES PATENTS Tyree Oct. 6, 1925 Angell Dec. 8, 1953

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