Sealing particulate matter in a micro-abrasive blasting device

A micro-abrasive blasting device comprises a mixing chamber, a delivery conduit extending from external the mixing chamber to the mixing chamber and a discharge conduit extending from the mixing chamber. Embodiments having delivery and discharge conduits extending from the same, or from opposite ends of the mixing chamber are disclosed. Abrasive material may selectively be sealed in the chamber by positioning the discharge conduit to abut the inlet port. Other sealing techniques are disclosed, such as capping or plugging the delivery and discharge conduits. The chamber may be spherical to deliver consistent powder perturbation at all mixing chamber orientations. Methods of using the device are disclosed. Methods of making the device by blow molding are disclosed.

FIELD

The invention relates generally to devices for propelling abrasive powder for etching a surface of a target material and, more particularly, micro-abrasive blasting devices powered by a pressurized-gas source for use with dental procedures, and features thereof.

BACKGROUND

Abrasive blasting devices operate on the physical property that gas at a higher pressure flows towards and into gas at lower pressure. When abrasive powder is mixed with gas at higher pressure, the gas carries the abrasive powder as the gas accelerates and flows to the lower pressure. As the gas and abrasive powder blast the target material at high speed, the impact of the particles removes layers of the target material. In dentistry this technology is known as micro-abrasion and is used to achieve a variety of goals—such as to remove foreign material or to dull a shiny surface, roughen or etch the surface to enhance bonding quality and to remove decay by drilling and cutting tooth structure.

Air abrasion devices are disclosed in U.S. Pat. No. 2,612,732 (Ziegler), U.S. Pat. No. 2,725,684 (Crow), U.S. Pat. No. 3,626,841 (Schachter) and U.S. Pat. No. 2,441,441 (Paache), and fall into two main categories: (i) providing a separate mixing apparatus for generating the abrasive laden air stream and delivering the abrasive laden air stream through an extended hand-piece for directing the stream onto the target surface, and (ii) integrating the mixing apparatus into the hand-held device.

The first category of devices facilitate more complex mechanisms and many operational options since the size and weight of the device are of no concern. Because the extended hand-piece delivers the abrasive laden air stream independent of the mixing operation, the hand-piece can be held at any orientation during operation. U.S. Pat. No. 6,083,001 (Deardon et al.) discloses a dental air abrasion system in which the flow of the particles is electronically controlled by pressure differentials. U.S. Pat. No. 6,093,021 (Rainey) discloses an automated control system which utilizes a gas stream mounted particulate sensor to regulate fluid flow rates into and around the ultrasonically agitated mixing chamber in order to accurately maintain the abrasive concentration in the air stream. Various methods for reducing the overspray of the abrasive have also been developed for these devices. U.S. Pat. No. 5,356,292 (Ho), U.S. Pat. No. 5,197,876 (Coston), and U.S. Pat. No. 6,024,566 (Burns et al.) disclose add-on splatter guard and collector attachments to air abrasion devices.

In the second category, the size, weight, and ergonomic shape of the device are significant factors. U.S. Pat. No. 5,199,299 (Herald et al.) and U.S. Pat. No. 6,439,966 (Burns et al.) disclose innovative hand-holdable air abrasion devices which mount the mixing apparatus into the hand-piece. The drawback of this approach is that the operation of these devices is limited by the orientation of the mixing chamber. An adjunct to the second category of devices has been the concept of simple self-contained air abrasion devices—such as U.S. Pat. No. 5,839,946 (Hertz), U.S. Pat. No. 6,287,180 (Hertz), U.S. Pat. No. 6,951,505 (Hertz), and U.S. Pat. No. 7,226,342 (Hertz), U.S. Pat. No. 6,398,628 (Groman), U.S. Pat. No. 6,347,984 (Groman), Schur et al. U.S. Pat. No. 6,004,191, and U.S. Pat. No. 6,354,924 (Trafton et al.). These devices rely on the air stream to perturb the abrasive and generate the mixing action based on U.S. Pat. No. 4,475,370 (Stark et al.) fixed air abrasion device for treating dental castings.

Merging of Stark's blow-through mixing method into the hand-piece so the mixing chamber is held between the user's fingers has taken air abrasion art to a new level. Because of their simplified structures, simple self-contained air abrasion devices tend to be less expensive to manufacture and can therefore be marketed to the user as disposable instruments.

With increased emphasis in Medical, Pharmaceutical, Cosmetic and Dental applications on reduced cross-patient contamination, there has been a significant drive towards single usage disposable packaging and devices. With advances in materials and fabrication technologies the cost of these devices has been significantly reduced. U.S. Pat. No. 4,391,590 (Dougherty) discloses a syringe and stopper like cartridge device for dispensing material while U.S. Pat. No. 5,839,946 (Hertz) discloses the formulation an air abrasion instrument from a syringe and stopper type structure. Both innovations capitalize on the lower cost of fabrication and the well established production methods of a syringe and stopper configuration.

Simple self-contained prior art air abrasion devices support an elongated cylindrical chamber with an inlet conduit for delivering the air into the mixing chamber and a discharge conduit for carrying the air-abrasive mixture out of the mixing chamber. The mixing chambers are utilized as a reservoir for storing the abrasive powder. Once the reservoir is depleted of abrasive material, the devices are discarded and therefore function as disposable instruments which do not require sterilization post intra-oral use.

To prevent the abrasive material from escaping the mixing chamber or becoming contaminated prior to use, simple self-contained prior art air abrasion devices add additional components which seal the inlet and outlet ports and conduits. While the U.S. Pat. No. 5,839,946 (Hertz), and U.S. Pat. No. 6,004,191 (Schur et al.) devices include passive caps which must be removed prior to using the instrument, U.S. Pat. No. 6,951,505 (Hertz) and U.S. Pat. No. 6,287,180 (Hertz), and U.S. Pat. No. 6,398,628 (Groman) and U.S. Pat. No. 6,347,984 (Groman) add functional components which actively prevent the abrasive from exiting the mixing chamber. U.S. Pat. No. 6,398,628 (Groman) discloses a filter that prevents the abrasive from exiting the device's inlet port and a movable discharge conduit which prevents abrasive material from exiting the mixing chamber when the discharge conduit inlet port abuts the side wall of the mixing chamber. U.S. Pat. No. 6,951,505 (Hertz) has a deformable seal at the inlet port external to the mixing chamber which functions as a check-valve that allows the pressurized-gas to enter the instrument but prevents abrasive from exiting the instrument. U.S. Pat. No. 6,398,628 (Groman) discloses a deformable and movable cap configurations which block both the delivery conduit inlet and discharge conduit outlet prior to use.

Another disposable delivery method disclosed by U.S. Pat. No. 6,343,717 (Zhang et al.) attempts to address the containment of stored material utilizing a pipette structure. A typical pipette consists of a slender pipe or tube that is used to transfer or measure small quantities of material from one location to another. The most common type of pipette consists of a small tube that widens into a bulb at the middle. The Zhang et al. pipette structure is made of a rigid or resilient material that is pre-filled with a pharmaceutical or cosmetic product and is used once and then discarded. Zhang et al. discloses a plurality of ways by which the disposable pipette can be sealed to contain the material and then unsealed by the user prior to use for dispensing the stored material. According to Zhang's et al. invention the majority of material is retained within the bulb section of the pipette, but Zhang's et al. sealing methods permit the contained material to migrate into the top and bottom tube sections. Although Zhang's et al. use of a pipette structure leads to a very cost effective means of delivering the contained material, Zhang's et al. sealing methods are not compatible with the needs of air abrasion devices.

Pressurized air stream is delivered to the simple self-contained air abrasion devices of Hertz, Groman, Schur, and Trafton via custom connectors which engage the device externally and to form a seal with the device body to deliver the pressurized air to the mixing chamber delivery port. The connectors are designed to supply clean dry air in order to maintain the abrasive powder dry, since any moisture causes clumping of the abrasive material and therefore the malfunction of the device. The dry air is required because the gas delivery conduit leads directly into the mixing chamber; therefore any liquid present at the entry to the device gets trapped in the mixing chamber. U.S. Pat. No. 6,293,856 (Hertz et al.) discloses a connector with additional conduits for carrying other types of fluids passively through the mixing chamber. This configuration requires a very complex connector to assure the separation of the fluids delivered to the air abrasion instrument without contaminating the mixing chamber. Custom connectors which supply dry air add to the installation cost and complexity of these disposable devices. And because they attach to the body of the devices, these connectors are typically very bulky.

Referring toFIGS. 1A,1B, prior art self-contained air abrasion devices use a blow-through methodology to agitate the abrasive powder. More specifically, these devices utilize the delivery conduit to deliver the gas stream into the abrasive material. As the gas stream blows through the abrasive material, the abrasive material is agitated. Gravity is utilized to assure that the non-aerated abrasive remains at the bottom of the mixing chamber. As the air stream reverses direction towards the discharge conduit inlet, aerated particles are captured by the air stream. The abrasive laden air stream is pushed out of the mixing chamber through the discharge conduit by the higher pressure gas source.

In their reduction to practice, both the Schur and Groman devices require the user to maintain the orientation of the device so the mixing chamber points downward. The attached user instructions for the Schur and Groman devices outline the specific user instructions cautioning the user about mis-orienting the mixing chamber. To compensate for his shortcoming, the marketed Groman instrument provides a finger bendable discharge conduit. The marketed Schur device provides a bending tool, so the user is able to form the delivery conduit to reach upper surfaces while maintaining the proper orientation of the mixing chamber.

Referring toFIG. 2, if the user attempts to utilize these prior art devices with the mixing chamber horizontal or upside down, the abrasive material is pushed directly into the discharge conduit without being properly mixed with the air steam. This leads to a concentration of abrasive material to exit the device in an uncontrolled manner, which creates a cloud of abrasive dust or clogs up the discharge conduit as the abrasive powder binds. Additionally, in certain orientations the delivery conduit is not immersed in the abrasive material which also disrupts the mixing operation of these prior art devices. In fact, the pressurized-gas exiting the delivery conduit creates a back pressure on the abrasive within the mixing chamber causing the abrasive powder particles to bind together instead of mix with the air stream. Most importantly, these disruption in flow can lead to a defective clinical procedure which either under or over etches the target tooth surface.

SUMMARY

Various embodiments of the invention disclosed herein may address and resolve shortcomings of the prior art, such as:eliminating the need for the inlet and outlet caps or other sealing methods.making the device insensitive to liquids at the pressurized-gas connection.making the air abrasive mixing operation independent of the orientation of the mixing chamber.eliminating back pressure buildup within the mixing chamber.eliminating the need for a bulky custom connection to the instrument for pressurized-gas delivery.

The air abrasion device disclosed herein may be made of a continuous tubing formed into a disposable pipette structure. Accordingly, some objects and advantages of the present invention may include:reducing component count by utilizing the discharge conduit in conjunction with the delivery conduit inlet to seal the abrasive material within the mixing chamber.creating a bypass to the mixing chamber so liquids in the pressurized-gas connection are purged out of the system without contaminating the abrasive within the mixing chamber.providing a spherical mixing chamber which assures a distal separation between the discharge conduit inlet and the abrasive powder at all mixing chamber orientations.eliminating the air stream reversal within the mixing chamber so back pressure is never created on the abrasive powder.extending the delivery conduit external to the mixing chamber so a slender handheld gas supply connector and standard tube fittings can be utilized for pressurized-gas delivery.making the disposable pipette structure usable for air abrasion applications in order to further reduce the manufacturing costs.

Another object of the invention may include that the material in the bulb of the pre-filled pipette may be protected from contamination or spillage by the discharge conduit.

In an embodiment of the invention, a micro-abrasive blasting device constructed from a disposable pipette structure comprising a delivery conduit extending from a delivery conduit inlet through a tapered section to form a delivery conduit outlet and a inlet port; contiguous pipette structure expands from inlet port to form a hollow bulb mixing chamber and then narrows to form a discharge port section; a discharge conduit is in fluid communications with discharge port and extends from a discharge conduit inlet internal to mixing chamber to a discharge conduit outlet external to mixing chamber; a particulate matter is disposed within mixing chamber wall; discharge conduit inlet abuts inlet port preventing particulate matter from exiting mixing chamber. A separation gap between the delivery conduit outlet and discharge conduit inlet is created as discharge conduit is displaced so discharge conduit inlet no longer abuts inlet port; As pressurized-gas is supplied to micro-abrasive blasting device through the delivery conduit inlet, the pressurized-gas flows through the delivery conduit and out of the inlet port, into mixing chamber. As flow is initiated, particulate matter instantaneously mixes with the gas-steam within hollow resilient bulb mixing chamber and the powder-gas mixture flows through discharge conduit to strike target surface.

In an embodiment of the invention, the discharge conduit has a U-shaped portion internal to the mixing chamber, and the device may be unsealed by pushing the discharge conduit into the mixing chamber (rather than pulling it out, as in other embodiments). The delivery conduit may also be U-shaped so as to terminate at the same wall of the chamber as the discharge conduit.

REFERENCE NUMERALS IN DRAWINGS

DETAILED DESCRIPTION

It should be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.

Reference is now made to the drawings, wherein like characteristics and features of the present invention shown in the various FIGURES (FIGs.) are designated by the same reference numerals. Various embodiments will be described.

An Embodiment

Referring toFIGS. 3A,3B,3C,3D, a micro-abrasive blasting device75is disclosed. Micro-abrasive blasting device75comprises a mixing chamber23formed by a mixing chamber wall25and supports an inlet port27and a discharge port29; a delivery conduit30extending from a delivery conduit inlet35external to mixing chamber23to a delivery conduit outlet37internal to mixing chamber23, by means of protruding into mixing chamber23through mixing chamber wall25at inlet port27; a discharge conduit10is in fluid communications with mixing chamber23at discharge port29, and extending from a discharge conduit inlet12internal to mixing chamber23to a discharge conduit outlet14external to mixing chamber23; a particulate matter50is disposed within mixing chamber23.

Referring toFIG. 3D, extending delivery conduit30external to the mixing chamber23facilitates a connection to a handheld pressurized-gas supply connector55. Not only does this innovative configuration simplify the type of connection required for supplying the pressurized-gas and therefore the cost of the air supply adaptor, it also facilitates a more narrow connection to the air abrasion device. Whereas, prior art devices connect to the mixing chamber body, this embodiment connects to a narrower delivery conduit. Therefore, the innovative micro-abrasive blasting device75may be mounted as a disposable tip onto a non-disposable handheld supply connector55. While handheld supply connector55is held by the user's fingertips, delivery conduit30of micro-abrasive blasting device75mounts into handheld supply connector55downstream of the user's fingertips. Because the innovative micro-abrasive blasting device75does not support the user's grip and bulky supply connector, micro-abrasive blasting device75can be made shorter and of less rigid material. This configuration greatly decreases the complexity and cost of the micro-abrasive blasting device75.

Referring toFIG. 3A, discharge conduit inlet12abuts delivery conduit outlet37as to prevent particulate matter50from exiting mixing chamber23, thereby sealing particulate matter50within mixing chamber23. As delivery conduit external section32engages with a pressurized-gas source, pressurized-gas is delivered to delivery conduit30at delivery conduit inlet35; the pressurized-gas passes through delivery conduit30into discharge conduit10to exit micro-abrasive blasting device75at discharge conduit outlet14. Since discharge conduit inlet12abuts delivery conduit outlet37the pressurized gas can not enter mixing chamber23.

Therefore, any moisture or liquid residue contained in or carried by the pressurized-gas does not enter mixing chamber23and is discharged through micro-abrasive blasting device75.

Referring toFIG. 3B, a separation gap45between the delivery conduit outlet37and discharge conduit inlet12is created as discharge conduit10is displaced so discharge conduit inlet12no longer abuts delivery conduit outlet37; As pressurized-gas is supplied to micro-abrasive blasting device75through delivery conduit inlet35, the pressurized-gas flows through delivery conduit30and out of delivery conduit outlet37into mixing chamber23. When gas flow is present, particulate matter50instantaneously mixes with the flowing gas and is dispensed through discharge conduit10to strike target surface40. Once mixing chamber23is depleted of particulate matter50, micro-abrasive blasting device75is removed from the pressurized-gas source and discarded.

Another Embodiment

Referring toFIGS. 4A,4B, a micro-abrasive blasting device75is comprised of a hollow resilient round tubular pipette structure80constructed of a thermoplastic material such as polycarbonate, polyethylene, polyester, polystyrene, polypropylene, polysulfone, polyurethane, ethylene-vinyl-acetate or the like. The material may be transparent, translucent, opaque, or pigmented to indicate the type of abrasive powder contained within the sealed mixing chamber. Pipette structure80may have a circular cross section but can also be fabricated out of other cross sectional shapes.

Micro-abrasive blasting device75is comprised of a pipette structure80which consists of three sections, a hollow bulb section forming a mixing chamber23; a open ended hollow tubular delivery conduit30section smaller in diameter and contiguous with the bulb section at inlet port27, for delivery of pressurized-gas; a hollow tubular discharge port29section smaller in diameter and contiguous with the bulb section, for discharging abrasive laden gas stream; a discharge conduit10in fluid communications with discharge port29, and extending from a discharge conduit inlet12internal to mixing chamber23to a discharge conduit outlet14external to mixing chamber23; a particulate matter50is disposed within mixing chamber23. Delivery conduit30section may extend from a delivery conduit inlet35through a external section32and a tapered section33to form a delivery conduit outlet37and a inlet port27.

The outer and/or inner diameter of delivery conduit external section32may be selected to fit standard tube or hose fittings, while the inner diameters of inlet port27and discharge port29may support an inner diameter that is equivalent to or less than the outer diameter of discharge conduit10. Design selections of these diameters may eliminate or reverse the gradient of delivery conduit tapered section33, rendering delivery conduit30a straight tube. The diameter of hollow resilient bulb mixing chamber23may be selected to support the appropriate quantity of particulate matter50to at least perform one dental procedure.

Pipette structure80may be formed via blow-molding and/or tube swaging techniques, or other thermo-forming processes. These methods would typically require that one of the ends of the tubular pipette structure80be sealed in order to entrap pressurized-gas for forming the component during the blow-molding process. The sealed end may be formed at the delivery conduit inlet35of delivery conduit30section or at the tip of discharge port29section. The sealed end may be trimmed off during the assembly process of micro-abrasive blasting device75or just punctured or cut to permit air flow into micro-abrasive blasting device75when mounted onto a pressurized-gas connector. Additionally, the pressurized-gas connector could support cutting or puncturing means for breaking the blow-molded seal when delivery conduit30is mounted on the pressurized-gas connector.

Referring toFIG. 4A, discharge conduit inlet12fits within or abuts inlet port27preventing particulate matter50from exiting mixing chamber23. As delivery conduit external section32engages with a pressurized-gas source, pressurized-gas is delivered to delivery conduit30at delivery conduit inlet35; the pressurized-gas passes through delivery conduit30into discharge conduit10to exit micro-abrasive blasting device75at discharge conduit outlet14. Since discharge conduit inlet12abuts inlet port27the pressurized gas can not enter mixing chamber23.

Referring toFIG. 4B, a separation gap45between the inlet port27and discharge conduit inlet12is created as discharge conduit10is displaced so discharge conduit inlet12no longer abuts inlet port27; As pressurized-gas is supplied to micro-abrasive blasting device75through delivery conduit inlet35, the pressurized-gas flows through delivery conduit30and out of inlet port27, into mixing chamber23. As flow is initiated, particulate matter50instantaneously mixes with the gas-steam within hollow resilient bulb mixing chamber23and the powder-gas mixture flows through discharge conduit10to strike target surface40.

Another Embodiment

Referring toFIGS. 5A,5B,5C,5D,5E, a micro-abrasive blasting device75may be constructed of a contiguous pipette structure80and may operate as embodiments ofFIGS. 3(A-D) andFIGS. 4(A-B). However, pipette structure80of theFIGS. 5(A-E) embodiment(s) supports a mixing chamber wall25constructed to form a hollow spherical bulb mixing chamber23. The spherical shape of mixing chamber23assures a distal separation between the discharge conduit inlet12and the particulate matter50at all orientations of mixing chamber23.

Referring toFIG. 6A, when micro-abrasive blasting device75is operated in a horizontal orientation, particulate matter50is pulled by gravity to the mixing chamber wall25at the bottom surface of mixing chamber23. Therefore, during operation, the spherical configuration of mixing chamber23keeps particulate matter50distant from discharge conduit inlet12, thereby maintaining the proper mixing action.

Referring toFIG. 6B, when micro-abrasive blasting device75is operated in a vertical orientation, the spherical shape of mixing chamber23also assures a distal separation between the discharge conduit inlet12and the particulate matter50at all mixing chamber23orientations. Additionally, the elimination of the delivery conduit internal section—referred to in the embodiment ofFIGS. 3(A-D) as delivery conduit internal section34—assures that the pressurized gas stream entering mixing chamber23at inlet port27always directs the pressurized-gas into particulate matter50thereby eliminating the potential for back pressure on particulate matter50.FIG. 6Cis simply another view of the micro-abrasive blasting device.

Referring again toFIGS. 5A-5B, a discharge conduit stop83is attached to discharge conduit10so discharge conduit stop83moves with discharge conduit10within mixing chamber23from inlet port27to discharge port29. Discharge conduit stop83provides a mechanical restriction to the displacement of discharge conduit10by creating a restriction at inlet port27and discharge port29. When discharge conduit stop83abuts inlet port27, discharge conduit inlet12is properly positioned to seal mixing chamber23. When discharge conduit stop83abuts discharge port29, discharge conduit inlet12is properly positioned to form separation gap45. Discharge conduit stop83could be integral to discharge conduit10through a flaring or bulging of discharge conduit10, a component mounted onto discharge conduit10via a gluing, swaging, heat-shrinking, or welding process etc., or simply a drop of dispensed glue.

Referring toFIG. 5A, as discharge conduit inlet12abuts inlet port27, discharge conduit stop83is positioned at inlet port27, restricting discharge conduit inlet12from protruding too deep through inlet port27. Discharge conduit stop83may locate discharge conduit inlet12within inlet port27such that potential liquid residue smoothly passes through micro-abrasive blasting device75.

FIGS. 5C and 5Dillustrate alternatives to the moveable discharge conduit performing sealing, as shown inFIGS. 5A and 5B. Referring toFIG. 5C, a removable closure element36which may be in the form of a plug or a cap may be disposed in or on the open distal (from the mixing chamber) end of the delivery conduit30, sealing it, to prevent abrasive material from escaping during shipping and handling Likewise, a removable closure element15which may be in the form of a cap or plug may be disposed on or in the open distal (from the mixing chamber) end of the discharge conduit30, sealing it, to prevent abrasive material from escaping during shipping and handling. Prior to use, the end plugs/caps36and15would be removed. In this removable closure element (caps or plugs) embodiment, the discharge conduit10need not be moveable, in which case the stop83(seeFIGS. 5A,5B) would not be required. If desired, the discharge conduit10could nevertheless be movable in the aforementioned manner ofFIGS. 5A,5B to additionally seal the abrasive material50in the mixing chamber23, or simply to make the discharge conduit retractable for shipping and extendable in use.

FIG. 5Dillustrates another alternative to the moveable discharge conduit performing sealing, as shown inFIGS. 5A and 5B. Here, an elongate rod31extends through the delivery conduit30. The rod36may fit snugly through the delivery conduit outlet37, and extend sufficiently beyond the outlet37so that an end of the rod31closes off the discharge conduit inlet12, thereby sealing abrasive material50in the mixing chamber23. Prior to use, the rod31would be removed (withdrawn). In this elongate rod embodiment, the discharge conduit need not be moveable, in which case the stop83would not be required. If desired, the discharge conduit10could nevertheless be movable in the aforementioned manner ofFIGS. 5A,5B to additionally seal the abrasive material50in the mixing chamber23, or simply to make the discharge conduit retractable for shipping and extendable in use.

Referring toFIG. 5E, which may be based on any of the embodiments described with respect toFIGS. 5A,5B,5C5D, the extension of delivery conduit30external to the mixing chamber23facilitates a more narrow connection to the air abrasion device via a handheld pressurized-gas supply connector55. Whereas, prior art devices connect to the mixing chamber body, this embodiment connects to a narrower delivery conduit30. Therefore, the micro-abrasive blasting device75may be mounted as a disposable tip onto a non-disposable handheld supply connector55. While handheld supply connector55is held by the user's fingertips, delivery conduit30of micro-abrasive blasting device75mounts into handheld supply connector55downstream of the user's fingertips. Because the innovative micro-abrasive blasting device75does not support the user's grip and bulky supply connector, micro-abrasive blasting device75can be made shorter and of less rigid material. This configuration greatly decreases the complexity and cost of the micro-abrasive blasting device75.

Some Other Embodiments

Referring toFIGS. 7A,7B, contiguous pipette structure80is extended to include an additional hollow bulb section to form a discharge conduit bearing82. The discharge conduit bearing82is a tubular extension of the discharge port29section, elongated from a capped position end95to a mixing position end97with a diameter equal to or greater than discharge conduit10. Discharge conduit bearing82provides mechanical support to discharge conduit10, to assure discharge conduit10properly displaces away from inlet port27; a discharge conduit stop83is attached to discharge conduit10so discharge conduit stop83moves with discharge conduit10within discharge conduit bearing82from the capped position end95to the mixing position end97. Discharge conduit stop83in conjunction with discharge conduit bearing82provides a mechanical restriction to the displacement of discharge conduit10. When discharge conduit stop83abuts capped position end95, discharge conduit inlet12is properly positioned to seal mixing chamber23. When discharge conduit stop83abuts mixing position end97, discharge conduit inlet12is properly positioned to form separation gap45.

Referring toFIG. 8, contiguous pipette structure80is extended to include a protective nozzle guard85. Protective nozzle guard85is constructed by extending pipette structure80so it encompasses discharge conduit outlet14, thereby providing protection to discharge conduit10external to mixing chamber23. Protection of the delivery conduit is important to prevent damage to the delivery conduit during shipping and from the delivery conduit puncturing other surrounding devices in bulk packaging. Nozzle guard85also prevents the delivery conduit from sticking the user when mounting micro-abrasive blasting device75onto the pressurized-gas connector.

Protective nozzle guard85may be removed prior to use, by pulling protective nozzle guard85coaxially to discharge conduit10, thereby fully exposing discharge conduit10. A perforation to pipette structure80may be provided at nozzle guard separation point87as to weaken pipette structure80at nozzle guard separation point87. Pulling on protective nozzle guard85coaxially to discharge conduit10, causes pipette structure80to separate at nozzle guard separation point87allowing the removal of protective nozzle guard85to expose discharge conduit10.

Referring toFIG. 9, contiguous pipette structure80is extended to include a portion of a hollow bulb section to form a particle deflector90. Particle deflector90is constructed by extending pipette structure80to form a semi-spherical bulb structure. Particle deflector90is positioned on discharge conduit10as to deflect particulate matter50ricocheting off the target surface during use.

Perforation to pipette structure80may be provided at particle deflector separation point93as to weaken pipette structure80at particle deflector separation point93. Pulling particle deflector90coaxially to discharge conduit10, separates particle deflector90at particle deflector separation point93to permit the movement of particle deflector90along discharge conduit10. Particle deflector90may be positioned near discharge conduit outlet14as to deflect particulate matter50ricocheting off the target surface during use. The pipette structure80may be constructed to include both protective nozzle guard85and particle deflector90.

Mixing Method

Referring toFIG. 3C, a separation gap45between the delivery conduit outlet37and discharge conduit inlet12generates rapidly expanding and contracting gas-stream that forms a pressure gradient48. The rapid expansion of the gas-stream occurs as the gas-stream exits the narrow delivery conduit outlet37and expands into the wider mixing chamber23. The rapid contraction of the gas-stream occurs as the gas-stream flows from the wider mixing chamber23into the narrower discharge conduit inlet12. Because mixing chamber23is a closed-system, the volumetric flow rate into mixing chamber23must equal the volumetric flow rate out of mixing chamber23. Expansion and contraction of the gas-stream across separation gap45is accompanied by a localized pressure gradient48at separation gap45. The pressure gradient48across separation gap45within mixing chamber23agitates particulate matter50causing particulate matter50to aerate. The aerated particulate matter50particles are pulled into the gas-stream at separation gap45, generating an abrasive laden gas stream into discharge conduit inlet12and out of discharge conduit outlet14. Because pressure gradient48across separation gap45is independent of mixing chamber23orientations, agitation also is independent of the orientation of mixing chamber23.

This mixing method is independent of the mixing chamber shape as long as the mixing chamber23is wider than the delivery conduit outlet37and discharge conduit inlet12. In the absence of delivery conduit outlet37where delivery conduit30terminates at inlet port27, this innovative mixing method still applies as pressure gradient48is formed across separation gap45. Since separation gap45controls the rapidness by which the gas-stream expands and contracts, the distance of separation gap45controls the agitation rate of particulate matter50within mixing chamber23. Therefore, the quantity of particulate matter50introduced into the gas-steam is selectable by the position of discharge conduit inlet12with respect to delivery conduit outlet37or inlet port27.

Some Additional Embodiments

In some of the embodiments disclosed herein, a micro-abrasive device (75) comprises a mixing chamber (23) for containing a supply of abrasive particulate matter (50) an inlet port (27) disposed at one end of the mixing chamber, and a discharge port (29) disposed at an opposite end of the mixing chamber.

A delivery conduit (30) is elongate, has a portion (32) external to the mixing chamber (23), and may have a portion (34) internal to the mixing chamber terminating in an outlet (37), and essentially passes through the inlet port (27). (SeeFIGS. 3A,3B) Alternatively, the delivery conduit (30) may terminate at the inlet port (27) without having an internal portion. (SeeFIGS. 4A,4B.) In use, the delivery conduit (30) is at the “user end” (or “back end”) of the mixing chamber (23), and the device (75) mounts to a handheld supply connector (55) which may be grasped by the user so that the device is positioned downstream of the user's fingertips

A discharge conduit (10) is elongate, has a portion internal to the mixing chamber (23) terminating in a discharge conduit inlet (12), may be moveable, essentially passes through the discharge port (29) and has an portion external to the mixing chamber (23) terminating in an outlet (14). In use, the discharge conduit (10) is at the “patient end (or “front end”) of the mixing chamber (23).

In many of the embodiments disclosed herein, the discharge conduit (10) is moveable from a “sealed” position with the discharge conduit inlet (12) abutting the delivery conduit outlet (37) so that pressurized gas can not enter mixing chamber (23), thereby sealing abrasive material (50) within the mixing chamber (23), such as after manufacturing, for shipping, and before use. In use, the user may pull the discharge conduit (10) outward, thereby distancing the discharge conduit inlet (12) from the delivery conduit outlet (37) and unsealing the device, thereby permitting pressurized gas to flow into the mixing chamber (23) for agitating the abrasive material for delivery via the delivery conduit (30).

This application claims benefit of Ser. No. 13/083,532 filed Apr. 9, 2011 which is a continuation of Ser. No. 12/764,939 filed Apr. 21, 2010 (U.S. Pat. No. 7,927,188) which is a division of Ser. No. 11/077,098 filed Mar. 10, 2005 (U.S. Pat. No. 7,731,570), all by Groman, incorporated by reference herein. Some features disclosed therein may be incorporated into the embodiments of the device(s) disclosed herein, for example, but not limited to . . .providing multiple delivery conduits (25) having different aperturesproviding multiple delivery conduits (25) having different lengthsproviding the gas-receiving port (39) and the discharge port (45) in the same end wall of the mixing chamber (23)selecting the length of the delivery conduit (25) and consequent position of the deliver conduit (27) relative the abrasive material to maintain a consistent gas flow perturbation onto the abrasive powder.

Some additional embodiments of the invention (some of which may have been disclosed or fairly implied in U.S. Pat. Nos. 7,731,570 or 7,927,188) will now be described, such asproviding an inlet port (27) and a discharge port (29) at the same end of the mixing chamber. In the device of U.S. Pat. Nos. 7,731,570 or 7,927,188, the inlet and outlet ports are both disposed in the back (user) end of the mixing chamber. In contrast therewith, in some embodiments of the device disclosed herein, the inlet and discharge ports are both disposed in the front (patient) end of the mixing chamber.arranging the delivery conduit which commences at the back (user) end of the mixing chamber to wrap around (pass along side of) the mixing chamber, entering the mixing chamber at the front (patient) end thereof.as in U.S. Pat. No. 7,607,972, the discharge conduit may be moveable to alternately seal and unseal the mixing chamber (allowing or preventing gas flow through the device). In U.S. Pat. No. 7,607,972, pulling the discharge conduit “out” from the mixing chamber will unseal the device. (Since the device is intended to be disposable, it is not anticipated that the pulled-out discharge conduit would be pushed back in to re-seal the device.) As disclosed herein, with both of the inlet port (27) and discharge port (29) disposed at the same end of the device, an internal portion of the delivery conduit may be U-shaped, and pushing the discharge conduit “into” the mixing chamber may unseal the device.an alternate configuration disclosed herein comprises providing an inlet port (27) and a discharge port (29) at opposite ends of the mixing chamber (as in most of the embodiments shown herein), but rather than the discharge conduit (10) being moveable to seal and unseal the device, the delivery conduit (30) is moveable to seal and unseal the device.
Both Ports at the Same (Front, Patient) End

FIGS. 10A,10B disclose an embodiment or configuration of the micro-abrasive blasting device75generally comprising:a mixing chamber23for containing a supply of abrasive particulate matter (50, not shown) and having two ends—a “user end”23aand a “patient end”23b;an inlet port27disposed at the patient end23bof the mixing chamber23; anda discharge port29disposed at the patient end23b(the same one of the two ends of the mixing chamber).

A delivery conduit30is elongate, situated external to the mixing chamber23along side of the mixing chamber, and extends from adjacent to (near, but not in fluid communication with) the user end23aof the mixing chamber23to the patient end23bof the mixing chamber23. At the user end (of the device), the delivery conduit30may extend further, terminating (or originating) at a delivery conduit inlet35for receiving pressurized gas from a supply (not shown). At the patient end23bof the mixing chamber23, the delivery conduit30terminates at a delivery conduit outlet37which is essentially coincident (contiguous) with the inlet port27of the mixing chamber23.

A discharge conduit10is elongate, has a portion11internal to the mixing chamber23terminating in a discharge conduit inlet12, may be moveable, essentially passes through the discharge port29of the mixing chamber23and has a portion13external to the mixing chamber23terminating in a discharge conduit outlet14.

In many of the embodiments disclosed herein, the discharge conduit10is moveable from a “sealed” position with the discharge conduit inlet12abutting the delivery conduit outlet37so that pressurized gas can not enter mixing chamber23. Unlike some of the previous embodiments (such asFIGS. 4A,4B,4C), where the inlet port27and discharge port29are disposed at opposite ends of the mixing chamber23, in the embodiment ofFIGS. 10A,10B, both the inlet port27and the discharge port29are located at the same end23bof the mixing chamber23. To facilitate this configuration, the internal portion11of the discharge conduit may be U-shaped, making a substantially 180-degree turn so as to be oriented towards the patient end23bof the mixing chamber.

FIG. 10Ashows the device75with the discharge conduit inlet12abutting the delivery inlet port27(delivery conduit outlet37)—this is the “closed” or “sealed” position—and gas is prevented from flowing through the device. (Abrasive material50within the mixing chamber23is omitted, for illustrative clarity.) The device75may be shipped in this “sealed” configuration, so that abrasive material does not leak out during shipping. Caps and plugs, as described with respect toFIG. 5Cmay be added to this (or other) embodiments.

FIG. 10Bshows the device75with the discharge conduit inlet12displaced from the delivery inlet port27(delivery conduit outlet37)—this is the “open” or “unsealed” position—and gas may flow through the device. (Abrasive material within the mixing chamber is omitted, for illustrative clarity.) The device75may be unsealed by the user, by pushing the discharge conduit10inward (to the right, as illustrated), thereby allowing gas to flow into the delivery conduit inlet35, through the delivery conduit30, into the mixing chamber23and perturbating abrasive material (50) which will be delivered to a target (such as patient's tooth) via the discharge conduit10out of the discharge conduit outlet14.

Benefits of this configuration may include . . .the overall device75becomes shorter when the discharge conduit10is unseated (pushed in to unseal the mixing chamber), which may provide more precise aim and positioning for the user (dentist, dental tech)the ability to contain more powder/particulate material (50) while keeping the overall device length shorterthe movable discharge conduit10may abut the device wall during operation, thereby providing resistance to movement during operationthe shape of the discharge conduit10may eliminate the need for a stop or protrusion (83)—in other words, it may not be pushed in too far. (Contrast this with the pulling out embodiments which comprise a stop, such as inFIGS. 5A,5B, to prevent pulling the discharge conduit completely out.)the air flow from the delivery conduit wall inlet port27(and end37of delivery conduit30) may eliminate the need for an inlet conduit (34) since the air flow is from the bottom side (end). This is another example of the delivery conduit30ending at the gas inlet port27, without extending (as an inlet conduit) into the chamber.

Various Configurations, Illustrated Schematically

FIG. 11Aillustrates, schematically, a micro-abrasive blasting device (75) comprising a mixing chamber (23), a delivery conduit (30) extending from one end (user end) of the mixing chamber (inlet port27omitted, for illustrative clarity), a discharge conduit (10) extending through an opposite end (patient end) of the mixing chamber (discharge port29omitted, for illustrative clarity) and having a portion (11) internal to the mixing chamber. Abrasive material (50) is omitted, for illustrative clarity. The discharge conduit (10) may be pulled, outward from the mixing chamber, to unseal (open) the device. CompareFIGS. 4A,4B. This represents a device configuration having inlet and discharge ports at opposite ends of the mixing chamber, and pull (the discharge conduit) to open.

FIG. 11Billustrates, schematically, a micro-abrasive blasting device (75) comprising a mixing chamber (23), a delivery conduit (30) extending from a user end of the overall device (adjacent the user end of the mixing chamber), alongside of the mixing chamber, making a “U-turn” and connecting to the patient end of the mixing chamber (inlet port27omitted, for illustrative clarity), a discharge conduit (10) extending from the same (patient) end of the mixing chamber (discharge port29omitted, for illustrative clarity) and having a U-shaped portion (11) internal to the mixing chamber. Abrasive material (50) is omitted, for illustrative clarity. The discharge conduit (10) may be pushed, inward into the mixing chamber, to unseal (open) the device. CompareFIGS. 10A,10B. This represents a device configuration having inlet and discharge ports at the same (patient) end of the mixing chamber, and push (the discharge conduit) to open.

FIG. 11Cillustrates, schematically, a micro-abrasive blasting device (75) comprising a mixing chamber (23), a delivery conduit (30) extending from one end (user end) of the mixing chamber (inlet port27omitted, for illustrative clarity), a discharge conduit (10) extending from the same (user) end of the mixing chamber (discharge port29omitted, for illustrative clarity) and making a “U-turn” and extending alongside of the mixing chamber to beyond the opposite (patient) end of the mixing chamber. Abrasive material (50) is omitted, for illustrative clarity. The delivery conduit (10) may be moved, inward and outward from the mixing chamber, to control the perturbation of abrasive material in the mixing chamber. Compare FIGS. 4A-4C of U.S. Pat. No. 7,731,570. This represents a device configuration having inlet and discharge ports at the same (user) end of the mixing chamber, and also a feature that the delivery conduit is moveable in and out of the mixing chamber to control perturbation.

FIG. 11Dillustrates, schematically, a micro-abrasive blasting device (75) comprising a mixing chamber (23), a delivery conduit (30) extending into one end (user end) of the mixing chamber (inlet port27omitted, for illustrative clarity) and having a portion within the mixing chamber, and a discharge conduit (10) extending from an opposite end (patient end) of the mixing chamber (discharge port29omitted, for illustrative clarity). Abrasive material (50) is omitted, for illustrative clarity. The delivery conduit (30) may be pulled, outward from the mixing chamber, to unseal (open) the device. ContrastFIG. 11A(this is the “opposite” ofFIG. 11A). This represents a device configuration having inlet and discharge ports at opposite ends of the mixing chamber, and pull (the delivery conduit) to open.

Summary of Claims from parent application Ser. No. 11/452,467 Filed Jun. 13, 2006

The following are representative of claims from the parent patent application.A micro-abrasive blasting device may comprise:a chamber having a chamber wall and a hollow interior;a inlet port in said chamber wall;a discharge port in the chamber wall;a delivery conduit elongated from a delivery conduit inlet external to said chamber to a delivery conduit outlet disposed within the chamber and extending in fluid communications through said inlet port;a discharge conduit elongated from a discharge conduit inlet internal to the chamber to a discharge conduit outlet external to the chamber and extending in fluid communications through said discharge port;a quantity of particulate matter disposed within said chamber; wherein a handheld pressurized-gas supply connector mounts to said delivery conduit external to the chamber.

Pressurized-gas supplied to delivery conduit inlet may pass through the delivery conduit outlet into the chamber to generate an abrasive laden gas stream out of said discharge conduit.

Said discharge conduit inlet may abut delivery conduit outlet to seal said particulate matter within said chamber.

Pressurized-gas supplied to delivery conduit inlet passes through the delivery conduit and discharge conduit without entering the chamber.

Displacement of said discharge conduit inlet away from delivery conduit outlet may unseal the chamber to allow pressurized-gas flow through the chamber to generate an abrasive laden gas stream.

The delivery conduit outlet may terminates at the inlet port of said chamber.

The chamber may be spherical.

A discharge conduit stop may be mounted to said discharge conduit is disposed within the mixing chamber to restrict the movement range of the discharge conduit.

A pre-filled disposable pipette structure for micro-abrasive blasting device may comprise:a hollow tubular pipette structure;said pipette structure having a hollow bulb section forming a mixing chamber;said pipette structure further having a open ended hollow tubular delivery section smaller in diameter and contiguous with the bulb section, for delivery of pressurized-gas;said pipette structure also having a hollow tubular discharge section smaller in diameter and contiguous with the bulb section, for discharging abrasive laden gas stream;a quantity of particulate matter disposed within said mixing chamber;a discharge conduit elongated from a discharge conduit inlet to a discharge conduit outlet;wherein said discharge conduit is mounted in fluid communications through said discharge section of said pipette structure so said discharge conduit inlet is internal to the mixing chamber and discharge conduit outlet is external to the mixing chamber.

A pressurized-gas connector may mount to said delivery section.

Pressurized-gas supplied to delivery section may pass through the delivery conduit outlet into the chamber to generate an abrasive laden gas stream out of said discharge conduit.

The discharge conduit inlet may abut delivery section to seal said particulate matter within said mixing chamber.

Pressurized-gas delivered to delivery section may pass through the delivery section and discharge conduit without entering the mixing chamber.

Displacement of said discharge conduit inlet away from delivery section may unseal the mixing chamber to allow pressurized-gas flow through the mixing chamber to generate an abrasive laden gas stream.

The pipette structure may be constructed of a thermoplastic material selected from a group consisting of: polycarbonate, polyethylene, polyester, polystyrene, polypropylene, polysulfone, polyurethane, or ethylene-vinyl-acetate.

The pipette structure may be formed by extrusion blow molding in a two-piece mold.

The pipette structure may be formed by thermoforming a plastic tube.

The mixing chamber may be spherical.

The may be hollow tubular delivery section may be extended internal to said mixing chamber.

The pipette's hollow structure may be configured in cross section as selected from a group consisting of round, oval, square, rectangular and polygonal shapes.

The pipette's bulb section may have a cylindrical configuration with each end having a cone-shaped taper interfacing on one end with the delivery tube section, and on the other end with the discharge tubular section.

A method of using a handheld gas supply connector with a device for propelling particulate matter may comprise the steps of:placing particulate matter within a mixing chamber, said mixing chamber comprising a mixing chamber wall, a inlet port at a one end of the chamber and a discharge port at an opposite end of the chamber and sized for completing at least one dental procedure;extending a gas delivery conduit disposed external to the mixing chamber in fluid communications through said inlet port into the mixing chamber to terminate at a delivery conduit outlet;holding a pressurized-gas supply connector in a manner by grasping said supply connector between two fingers of one hand during the application of said device for at least one dental procedure;mounting said gas delivery conduit external to the chamber to said handheld supply connector whereby the mixing chamber is downstream of the fingers grasping location;applying gas flow through the gas delivery conduit into the mixing chamber;discharging a mixture of gas flow and said particulate matter through a discharge conduit in said discharge port for abrading at least one target surface of a dental procedure.

The delivery conduit outlet may terminate at said inlet port of the mixing chamber.

A method of sealing particulate matter within a device for propelling particulate matter may comprise the steps of:placing particulate matter within a mixing chamber, said mixing chamber comprising a mixing chamber wall, a inlet port at a one end of the chamber and a discharge port at an opposite end of the chamber and sized for completing at least one dental procedure;extending a gas delivery conduit disposed external to the mixing chamber in fluid communications through said inlet port into the mixing chamber to terminate at a delivery conduit outlet;inserting a discharge conduit in fluid communication through said discharge port extending from a discharge conduit inlet internal to said chamber to a discharge conduit outlet external to the chamber;positioning said discharge conduit inlet to abut said delivery conduit outlet thereby sealing particulate matter within the mixing chamber.

Pressurized-gas supplied to said gas delivery conduit may pass through the delivery conduit and discharge conduit without entering the mixing chamber.

Displacing said discharge conduit inlet away from said delivery conduit outlet may unseal the chamber.

Delivering pressurized-gas to said gas delivery conduit may pass through the delivery conduit outlet into the chamber to generate an abrasive laden gas stream out of said discharge conduit.

The delivery conduit outlet may terminate at said inlet port of the mixing chamber.

A method for generating an abrasive laden gas stream within a micro-abrasive blasting device may comprise the steps of:placing particulate matter within a mixing chamber, said mixing chamber comprising a mixing chamber wall, a inlet port at a one end of the chamber and a discharge port at an opposite end of the chamber and sized for completing at least one dental procedure;extending a gas delivery conduit disposed external to the mixing chamber in fluid communications through said inlet port into the mixing chamber to terminate at a delivery conduit outlet;inserting a discharge conduit in fluid communication through said discharge port extending from a discharge conduit inlet internal to said chamber to a discharge conduit outlet external to the chamber;positioning said discharge conduit inlet to have a separation gap with said delivery conduit outlet;applying a gas flow through the gas delivery conduit into the mixing chamber whereby forming a pressure gradient across said separation gap;aerating said particulate matter to mix with the said gas flow;discharging a mixture of gas flow and said particulate matter through a discharge conduit in said discharge port for abrading at least one target surface of a dental procedure.

The delivery conduit outlet may terminate at said inlet port of the mixing chamber.

In addition to the above, the following are disclosed but may not have been claimed in the parent application:

A micro-abrasive blasting device may comprise:a chamber having a chamber wall and a hollow interior;an inlet port in said chamber wall;a discharge port in the chamber wall;a tubular delivery conduit section contiguous with said chamber wall elongated from a delivery conduit inlet external to said chamber to a delivery conduit outlet terminating at said inlet port;a tubular discharge section contiguous with said chamber wall elongates from said discharge port external to said chamber;a discharge conduit elongated from a discharge conduit inlet internal to the chamber to a discharge conduit outlet external to the chamber and extending through said tubular discharge section and in fluid communications with said tubular discharge section;a quantity of particulate matter disposed within said chamber;wherein a handheld pressurized-gas supply connector mounts to said tubular delivery conduit section external to the chamber;wherein:a discharge conduit stop mounted to said discharge conduit is disposed external to the mixing chamber to prevent the extraction of the discharge conduit out of the tubular delivery conduit section and tubular discharge section.

A discharge conduit bearing may comprise a elongated tubular extension of the discharge port extending from the mixing chamber, a portion of which has a diameter equal to or greater than the discharge conduit;wherein the discharge conduit stop is disposed within the discharge conduit bearing.

A micro-abrasive blasting device may comprise:

a mixing chamber comprising a wall, an inlet port disposed in the wall and a discharge port disposed in the wall;

a delivery conduit extending from external the mixing chamber to the inlet port;a discharge conduit extending from internal the mixing chamber, through the discharge port, to external the mixing chamber, and having a discharge conduit inlet disposed within the mixing chamber; anda discharge conduit bearing comprising a elongated tubular extension of the discharge port extending from the mixing chamber, a portion of which has a diameter equal to or greater than the discharge conduit;wherein the discharge conduit stop is disposed within the discharge conduit bearing.

A micro-abrasive blasting device may comprise:a mixing chamber comprising a wall, an inlet port disposed in the wall and a discharge port disposed in the wall;a delivery conduit extending from external the mixing chamber through the inlet port to within the mixing chamber; anda discharge conduit extending from internal the mixing chamber, through the discharge port, to external the mixing chamber, and having a discharge conduit inlet disposed within the mixing chamber.

The delivery conduit may extend to within the mixing chamber.

A micro-abrasive blasting device may comprise:a mixing chamber comprising a wall, an inlet port disposed in the wall and a discharge port disposed in the wall;a delivery conduit extending from external the mixing chamber to the inlet port;a discharge conduit extending from internal the mixing chamber, through the discharge port, to external the mixing chamber, having a discharge conduit inlet disposed within the mixing chamber, and having a portion including a discharge conduit outlet disposed external the mixing chamber; anda protective nozzle guard extending from the mixing chamber and encompassing the discharge conduit outlet

A particle deflector may be positioned on the discharge conduit, in the form of a semi-spherical bulb structure, for deflecting particulate matter ricocheting off a target surface during use.

A micro-abrasive blasting device may comprise:a mixing chamber comprising a wall, an inlet port disposed in the wall and a discharge port disposed in the wall;a delivery conduit extending from external the mixing chamber to the inlet port;
a discharge conduit extending from internal the mixing chamber, through the discharge port, to external the mixing chamber, and having a discharge conduit inlet disposed within the mixing chamber; anda particle deflector positioned on the discharge conduit, in the form of a semi-spherical bulb structure, for deflecting particulate matter ricocheting off a target surface during use.
Advantages

From the description(s) above, the following advantages may become evident:(a) Use of the delivery conduit to seal the mixing chamber, thereby:1. reducing the component count; and2. making disposable pipette structure usable for air abrasion applications.(b) Use the delivery conduit to create a bypass to the mixing chamber, thereby eliminating liquid entrapment within the mixing chamber.(c) Extending the delivery conduit external to the mixing chamber, thereby making the device adaptable to a handheld gas supply connector and standard tube fitting.(d) Generation of a localized pressure gradient within the mixing chamber to generate and control powder agitation rates.(e) Use of a spherical mixing chamber to deliver consistent powder perturbation at all mixing chamber orientations.(f) Simplified construction using contiguous pipette structure fabricated to form the body of the micro-abrasion device.(g) the “push to open” feature (FIG. 10) allows for a shorter discharge conduit

While the invention has been described, disclosed, illustrated and shown in various terms or certain embodiments or modifications which it has assumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.

Summary, Ramification, and Scope

The present invention may accomplish the above-stated objectives, as well as others, as may be determined by a fair reading and interpretation of the entire specification.

Accordingly, the reader will see that the micro-abrasive blasting device may have reduced components, simplified construction, enhanced mixing methodology, and mountable to handheld gas supply connector.

Furthermore, the micro-abrasive blasting device has the additional advantages in thatit provides a more narrow pressurized-gas supply connection.it provides a sealed device that is resistant to fluid contamination.it provides a reliable device that delivers a consistent quantity of abrasive at any orientation.it provides the user with ability to select powder delivery rates by external manipulation of the discharge conduit position.it provides a simplified construction methodology which reduces the manufacturing cost of the product.