AU661074B2 - Improved dental suction unit - Google Patents

Description

TAMES THOMAS FERRIE

AUSTRALIA

Patents Act 1990

'S

S S

S

SS *S

S

*5 S S 5*

*S.S

S S SS S. S 4 S

S.

SS S 5.555

S

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLE~D: "IMPROVED DENTAL SUCTION UNIT" This invention is described in the following statement: -2- This invention relates to suction units of the kind used in dental surgeries for withdrawing water, saliva etc. from a patient's mouth while he or she is seated in a chair.

Liquids such as water and saliva and solid particles such as pieces of filling material are apt to accumulate in the patient's mouth to his own discomfort and to the hindrance of the dental surgeon attending to him. Particularly is this so when a water-spray device is used e.g. in conjunction with a drill.

Air and like suction units are known for withdrawing liquids such as water and possibly dissolved or suspended matter such as saliva and/or solid particles.

However many of these units involve direct disposal of the liquid etc or the collection of liquid etc. in a chamber which requires periodical cleaning by hand.

As this presents the likelihood of persons coming into contact with the patient's blood and/or other body fluid, and particularly having regard to the incidence of disease such as A.I.DS., many such prior devices are considered unsafe or have 5. for other reasons fallen into disfavour.

An object of my invention is to provide an "automated" dental suction unit that is simple and relatively safe.

Other objects and advantages will become apparent hereinafter.

Accordingly the invention provides a suction unit capable of effecting controlled disposal to waste of liquids such as water and aqueous solutions or suspensions of saliva, blood and solid particles and other waste or surplus material from a cavity or vessel open to ambient pressure such as the mouth of a dental patient, by means of a suction nozzle/hose of a kind knowrn per se, said unit -3including a chamber an upper part of which is adapted for connexion to the hose, to air suction means, and to a water mains or other supply of cleansing liquid, a drain in a lower part of the chamber, valve means in said drain responsive to chamber pressure, and means for controlling said air suction means between a first operative position wherein said valve means are closed to allow material to be sucked from the vessel or patient's mouth into the chamber for temporary retention in said chamber, and a second or drain position wherein the suction is cut off or reduced such as to permit the valve means to open and material to drain to waste from the chamber.

Correspondingly the invention also provides a method of removing liquid from the mouth of a dental patient or other vessel open to ambient air pressure without personal contact in the removing, comprising the steps of: providing for said liquid an intermittently-flushable suction receptacle with a drain held closed by the suction and openable when and only 36' when said suction is removed; establ;shinu che suction to close the drain and induce a flow of said liquid into an upper part of the receptacle for temporary collection in said receptacle; when a sufficient or predetermined quantity of liquid has been so c" 3ted, removing said suction thereby stopping said liquid flow and opening the drain; during the ensuing drainage, flushing the receptacle, and 24/931.1'6293,1'.3,3 -3Aafter completion of said drainage and flushing, re-establishing the SL' tion so as to close the drain enabling the receptacle to collect a further charge of liquid.

But in order that the invention may be better understood reference will now be made to the accompanying drawings which are to be considered as part of this specification and read herewith.

In the drawings: Fig. 1 is a vertical cross-section of a unit according to a first practical i ii

•S

i r i* i *i *24/5 y3.,Gt -4embodiment of the invention; Fig. 2 is a vertical cross-section of a chamber for a unit according to a second practical embodiment of the invention; Fig. 3 is a vertical cross-section of the unit of which the chamber shown in Fig. 2 forms part, connected to a flushing tank being another part of the unit; and Fig. 4 is an enlarged vertical section of the flushing tank shown in Fig. 3.

Both of the illustrated embodiments or models have for their objective the removal of waste materials from a patient's mouth via a known type of suction nozzle and hose (not shown) for temporary collection in a chamber or tank for eventual disposal to a sewer or other waste means.

S• Both models are identical or very similar i.e. air and liquids and any small solid particles entrained therein are withdrawn from an open cavity or vessel (eg.

a patient's mouth) to chamber 5 via port 6.

Referring to the drawings in more detail, the unit of Fig. 1 has a generally cylindrical chamber or tank 5 which is closed except for ports 6 to 9 as follows: 6 is an inflow port being an intake for the hose carrying material such as air, liquids etc. from the patient's mouth; 7 is an air outflow port; 8 is one of a number of mains water inflow nozzles or sprays; and 9 is an outflow drain.

Air is withdrawn from the upper part of chamber 5 via port 7 which leads qA into a suction manifold from which air is withdrawn by a suction pump (not 9A shown). Flow through manifold q W is controllable by a manually operable/adjustable "butterfly" valve 11. Liquids and solid particles are normally held in chamber 5. Drain 9 is closable by a plug in the form of a rubber ball valve 10 which is normally thrust against the outside of the drain opening by excess of ambient pressure over chamber pressure.

As liquid level rises in chamber 5, float assembly 12 rises correspondingly and at a predetermined level doses port 7.

When the suction is removed with consequent rise of chamber pressure, valve 10 is unseated allowing liquid to drain from the chamber to a suitable waste outlet 16. This may happen when, the suction pump is turned off, or when valve 11 is closed or when float 12 doses port 7.

9 Water delivered under pressure through a plurality of nozzles such as 8 provides a flushing and consequently cleansing action for the interior of the tank.

The nozzles may be somewhat tangentially inclined with respect to the tank's axis to provide a vortical or swirling motion to the flushing water. In general the water may be admitted for so long as, but only so long as, drain 9 is open. The water flow may be controlled by manually operable ball valve assembly 17 linked to mechanism 15 by slotted crank 18 to which is fixed cam 19 of mechanism 15. The crank may open a vent (not shown) in the chamber, allowing entry of ambient air to facilitate drainage of the tank contents, including fhe flushing water. The valve arm may carry a spring-influenced depressible rod 14 with finger 13 capable of Spositively dislodging valve 12 from suction port 7.

-6- Another vent for the chamber may be provided by a shuttle valve comprising a 10mm steel t;lU 20 in a tube 21 communicating with the interior of chamber 5 which permits ambient air to bleede in past the ball when the suction is interrupted by closure of port 7 such as by undesired entry by leakage of water through 8.

It will be seen that the embodiment of Fig. 1 admits mains water direct into the chamber, with just a possibility that in the event of malfunction infectious material may be placed in communication with, and possibly withdrawn into, the mains supply.

With such an eventuality in view, some water supply authorities (e.g.

Melbourne Water) rule that an effective "break" must be provided between the mains tap or outlet and the maximum possible level of dangerous or potentially dangerous liquid.

In these circumstances the unit of Figs. 2 to 4 may be used. An air break is achieved by supplying mains water to a cistern 22 effectively separate from tank Cistern 22 is divided into upper and lower reservoirs 23, 24 respectively.

Reservoir 23 is open to the atmosphere and has a ball cock 25 through which e.g.

mains water can be supplied at a predetermined, prescribed or regulated minimum leiel 30 mm) above the maximum level of water in the tank. Overflow 26 defines this maximum level, Lower reservoir 24 is substantially closed. It includes a float 27, pressure relief valve 28, air entry port 29 and water exit port Water falls from 23 to 24 via a large-area passage 31 closable by float 27.

-7- Reservoir 24 is pressurized via 29 with air e.g. from the suction unit aforementioned, and water is forced from 24 to chamber 5 via conduit 32. The suction unit is provided with air pressure regulator and ball valve assembly 33 in association with the water supply valve.

An operating knob or lever may be provided. One quarter-turn of the operating knob may simultaneously: 1. Open the water valve to permit flushing water to enter chamber 2. Close the butterfly valve to stop or reduce suction and thereby cause the tank to empty; and (in the caie of Figs. 2 to 4) 3. Open the air valve to pressurize the lower reservoir.

0* It will be evident from the foregoing that my unit is relatively simple in nature and provides a convenient means fc r collecting and disposing of fluids from the patient's mouth with relative safety to the dental surgeon and his staff.

It will also be clear that my invention, including both illustrated embodiments, is extremely simple in nature and normally the only action required by the operator is e.g. a quarter-turn of the operating handle or lever. This will empty and flush at any time or, if the float has risen so as to block the suction, will 0.000. dislodge it, with a resulting flushing action and resumption of operation.

AlthouBi cte invention has been particularly described by reference to a suction unit for dentists, its principles, as will readily be understood, have considerably wider application i.e. wherever dangerous or potentially dangerous liquids etc. have to be safely disposed of e.g. possibly in the treatment of human corpses etc.

-8- For the purposes of this specification terms such as "upper", "lower" and "bottom" are to be read as referring to the unit in a position of use, and not as necessarily limiting.

S.

SS

S. S

S

S*

SS

*eS.S.

S

S

S S

Claims (3)

1. 2. A unit as claimed in claim 1 wherein the cleansing liquid is water from a mains supply to an upper open reservoir part of a cistern separate from said chamber, the cistern having a lower reservoir part capable of receiving water from the upper part, and means for pressurising said lower part to force water to the chamber as and when required.
2. 3. A method of removing liquid from the mouth of a dental patient or other vessel open to ambient air pressure without personal contact in the removing, comprising the steps of: providing for said liquid an intermittently-flushable suction receptacle with a drain held closed by the suction and openable when and only when said suction is removed; establishing the suction to close the drain and induce a flow of said liquid into an upper part of the receptacle for temporary collection in said S receptacle; when a sufficient or predetermined quantity of liquid has been so collected, removing said suction thereby stopping said liquid flow and opening the drain; during the ensuing drainage, flushing the receptacle, and *00 6(5) after completion of said drainage and flushing, re-establishing the suction so as to close the drain enabling the receptacle to collect a further charge of liquid.
3. 4. A method for the removal and controlled disposal to .vaste of a liquid, substantially as herein described. A dental suction unit substantially as herein described with reference to Fig. 1, or Figs. 2 to 4 inclusive of the accompanying drawings. DATE D this 1th day of April, 1995. JAMES THOMAS FERRIE By 'a nt Attorney: ETER N HOJ.LS i^ r1214195LIVC23.11o,o10 Ll ABSTRACT A dental suction unit for the safe disposal of blood and other possibly infected or otherwise dangerous fluids, having a dosed chamber into which the fluids are induced and collected by suction applied to the chamber and from which the fluids are flushed and drained when said suction is removed. *9* o*