US 3718974 A
A control system for exhausting coolant water which is trapped within a dental handpiece coolant water supply line upon deactuation of the handpiece to eliminate drip at the handpiece. Compressed air which actuates a coolant water supply valve is exhausted into a branch line upon closing of the supply valve. The exhaust air opens a valve positioned between the water coolant line and drain facilities. The trapped coolant water flows into the drain through the open exhaust valve reducing the trapped water and pressure in the coolant water supply line. The exhaust air is relieved slowly through a choke after opening the exhaust valve, permitting the exhaust valve to close slowly enabling a sufficient quantity of trapped water to be exhausted.
Description (OCR text may contain errors)
United States Patent [191 Buchtel et al.
[ DENTAL HANDPIECE DRIP CONTROL SYSTEM  Inventors: Dean H. Buchtel; Kenneth R. Lappin; John A. Maurer, all of Canton, Ohio  Assignee: The Weber Dental Manufacturing Company, Canton, Ohio  Filed: Sept. 20, 1971  Appl. No.: 181,671
[451 March 6, 1973 Primary Examiner-Robert Peshock Att0rney-Frease & Bishop [5 7] ABSTRACT A control system for exhausting coolant water which is trapped within a dental handpiece coolant water supply line upon deactuation of the handpiece to eliminate drip at the handpiece. Compressedair which actuates a coolant water supply valve is exhausted into a branch line upon closing of the supply valve. The exhaust air opens a valve positioned between the water coolant line and drain facilities. The trapped coolant water flows into the drain through the open exhaust valve reducing the trapped water and pressure in the coolant water supply line. The exhaust air is relieved slowly through a choke after opening the exhaust valve, permitting the exhaust valve to close slowly enabling a sufficient quantity of trapped water to be exhausted.
8 Claims, 4 Drawing Figures PATEHEL @1375 3,718,974
SHEET 2 OF 2 27 24 INVENTORS.
DEAN H. BUCHTEL. KENNETH R. LAPPIN ATTORNEYS DENTAL HANDPIECE DRIP CONTROL SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to dental handpieces used by a dentist in performing dental work. More particularly the invention relates to a drip control system for exhausting excess pressure and water trapped in lines connected to the handpiece which supply cooling water to the handpieces during cutting and drilling operations, preventing such coolant water from dripping at the handpieces when the handpiece is not in use.
1 Description of the Prior Art Dental handpieces are one of the most important tools used by a dentist in performing dental work, such as for high or low speed cutting or dn'lling operations. The handpieces require a supply of air or water, or a combination of air and water for either driving power, cooling purposes, or both.
The flow of water to such handpieces usually is control-led by a foot pedal mounted on the floor adjacent a dental chair. The pedal when actuated by the dentist's foot, operates water and/or air actuated valves positioned within a dental console or tray assembly to admit a supply of coolant water through a supply line into the handpiece.
Problems arise in the use of such handpieces, in that after closing the control valves to stop the flow of coolant water to the handpiece, the water trapped in the supply line between the handpiece and closed valve drips from the water spray opening or other opening in the handpiece.
Although the amount of water drippage is mall, it is an inconvenience to the dentist and patient, especially when the handpiece is started and stopped several times during a drilling or cutting operation. Likewise, use of the handpiece throughout the day results in considerable drippage onto the handpiece storage rack, floor and the like.
The valve controlling the flow of coolant water to the handpiece preferably is located within the dental cabinet with the various piping, valves and other control apparatus to provide an attractive dental unit. The handpiece usually is attached at one end of a flexible tube sufficiently long to permit easy movement of the handpiece by the dentist, and therefore some distance from the water coolant control valve.
Thus, when the control valve is closed, the trapped water in the isolated section of line is forced through any opening in the handpiece since the water is under pressure and such pressure is still acting on the trapped water.
These situations have presented problems in the art and we are unaware of any drip control system which eliminates such handpiece water drippage in a simple and effective manner.
SUMMARY OF THE INVENTION Objectives of the invention include providing a dental handpiece drip control system incorporated into the piping connections and supply line components within a dental console or cabinet which prevents the coolant water trapped within the handpiece supply line from dripping from the handpiece after closing the supply line control valves; providing a dental handpiece drip control system which exhausts trapped coolant LII water in the handpiece supply line into a dental unit drain line and which permits the coolant water control valve to be concealed within the dental cabinet removed from the handpiece to present an attractive dental unit; providing a dental handpiece drip control system which uses the same air for actuating the water exhaust valve as is used for actuating the coolant water supply valve; providing a dental handpiece drip control system which is quiet in operation; and providing a dental handpiece drip control system which satisfies the stated objectives using usual components of simple and inexpensive design, and which avoid difficulties heretofore encountered in a simple, effective, and inexpensive manner, and which solve problems and satisfy existing needs in the art.
These objectives and advantages are obtained by the dental handpiece drip control system, the general nature of which may be stated as including a main water supply, a dental handpiece, a water pipeline connecting the supply with the handpiece, first water control valve means in the water pipeline between the water supply and the handpiece, means for actuating the first control valve means, a junction in the water pipeline between the first valve means and the handpiece, second valve means connected with the junction, drain means connected with the second valve means, the first and second valve means being operatively interconnected whereby operation of the first valve means stopping the flow of water from the water supply to the handpiece opens the second valve means exhausting water trapped in the water pipeline between the handpiece and the first valve means through the second valve means into the drain means; the actuating means for the first valve means including a supply of compressed air, an air supply pipeline connecting the supply of compressed air with the first valve means, means in the air supply pipeline for controlling the flow of compressed air in the pipeline foroperating the first valve means, an air exhaust pipeline connected with the supply air pipeline and second valve means through the compressed air control means whereby upon shutting off the flow of compressed air into the air supply line by the control means, the compressed air trapped in the air supply line exhausts into the air exhaust pipeline through the control means and actuates the second valve means; check valve means in either the air supply pipeline or air exhaust pipeline to trap exhaust air between the second valve means and the check valve means, choke means in the air exhaust pipeline, water heater means in the water pipeline between the first valve means and the main water supply, and a selector valve block means in the water pipeline between the junction and the handpiece whereby a plurality of handpieces may be connected to the selector valve block means and controlled by the first and second valve means.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a dental cabinet or unit in which the handpiece drip control system and components may be housed for usual handpieces shown supported by a tray arm mounted on the cabinet;
FIG. 2 is a diagrammatic view illustrating piping connections, components and control lines provided for the handpiece drip control system;
FIG. 3 is an enlarged fragmentary view, with portions broken away and in section, of a foot controller for controlling the supply of coolant water to the handpieces; and
FIG. 4 is an enlarged sectional view of an air actuated water control valve used in the drip control system.
Similar numerals refer to similar parts throughout the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT The invention is shown typically in the drawings and is incorporated in the illustrated dental cabinet or unit 1 (FIG. I). The cabinet 1 may have any desired size or type of construction, may house other dental appliances or accessories, may be mounted on a wall or on a floor, and may have suitable plumbing connections for a main water supply and drain or waste facilities.
Cabinet 1 is located conveniently to a dental chair to be readily accessible to the dentist or his assistant and may be of the type described in our copending application, Ser. No. l55,659,filed June 16, 1971.
A usual pivoted tray arm 2 may be mounted on and extend outward from the top-of cabinet 1 and includes a support platform 3 having a tray 4, recess mounted thereon. A number of manual handpieces 5 may be removably supported on either side of platform 3 as illustrated, or may be housed within cabinet 1.
A foot controller 6, for operating desired dental equipment accessories including handpieces 5, is located on the floor adjacent cabinet 1 and a dental chair. Controller 6 may be connected through a flexible conduit 7 with a junction box 8, and electrical power and air lines may pass through conduit 7 between foot controller 6 and junction box 8.
Another flexible conduit 9 extends between junction box 8 and cabinet 1, and air, electric power, water and drain lines may pass through conduit 9 between junction box 8 and cabinet 1.
A main water supply pipe 10 (FIG. 2) for supplying water for the handpieces and for accessories with which the dental unit 1 may be equipped may extend through a partition support member 11, and is supported thereon by flange 12. Support member 11 is mounted in any suitable manner within cabinet 1 near the bottom thereof. Another support member 13 also may be mounted within cabinet 1 spaced above member 1 1 and near the top of cabinet 1.
Water in main supply pipe 10 then flows through pipe section 14 to manual water shutoff valve 15. Valve 15 preferably is provided so as to permit repairs to any water lines beyond valve 15 and also to provide a cutoff in case of power failure which might affect the operation of solenoid operated valves or other components of apparatus housed in cabinet 1.
A conduit 16 connects manual valve 15 with solenoid controlled valve 17 which normally acts as the main water control valve for cabinet 1 and all accessories therein which are sup-plied with water. Valve 17 is operated by a solenoid indicated at 18 which may be energized through power lines 19 which are connected to a source of electric power and preferably are controlled by a switch located at cabinet 1.
Water flowing through valve 17 when the valve is open then flows through conduit 20 to a manifold 21 mounted at 22 on partition 13. Manifold 21 may serve as the source of water supply for all accessories which may be housed in cabinet 1.
For the purpose of the handpiece drip control system a cold water outlet line 23 is connected to and extends from manifold 21 to a tee 24 and connects by branch line 25 to a water heater 26. Another section 27 of cold water line 23 extends from tee 24 to provide cold water for other various dental accessories within cabinet 1.
A heated water outlet line 28 extends from a tee 29 connected to the hot water outlet 30 of water heater 26 and connects to a pressure regulator 31. Regulator 31 may be adjusted to provide the desired water pressure for the various handpieces 5 supplied with water from the pressure regulator 31 through its outlet 32.
Another heated water line 33 extends from tee 29 to provide heated water to other dental apparatus, such as a dental syringe, a patient drinking cup and the like.
Regulator 31 may be supported on an intermediate partition member 34 which is mounted within cabinet 1 and may be attached to member 34 by flanges 35.
A water pressure gauge 36 is connected with pressure regulator outlet 32 by a conduit 37, and an outlet conduit 38 from gauge 36 is connected to the water inlet 39 of an air operated water coolant supply valve 40.
Valve 40 may be attached to partition member by flanges 41 which are connected to the air inlet 42 of valve 40. A flexible conduit 43 extends from inlet 42 of valve to footpedal 6 through flexible conduits 7 and 9, and junction box 8.
A conduit 44 extends from water outlet 45' of valve 40 to a tee 46. A handpiece cooling water supply line 47 extends from tee 46 to a master selector valve block 48.
Valve block 48 contains a number of valves, one for each handpiece to be supplied with coolant water, and is positioned remote from foot controller 6 in cabinet 1. Individual air control lines 49, 50 and 51 may connect with block 48 and switch means (not shown) which may be mounted on tray platform 3, or. on cabinet 1, for selectively operating the coolant water valves within block 48. Lines 49-51 preferably are supplied with air which passes through and is controlled by valve 71 within foot controller 6.
Valve block 48 also may contain valves for supplying coolant air to the individual handpieces and also for supplying the drive air, dry or oil saturated, to the handpiece turbines.
Water coolant supply lines 52, 53 and 54 extend from their respective valves within block 48 and connect with handpiece metering valves 55, 56 and 57, respectively. Flexible outlet tubes 58, 59 and 60 extend from their respective metering valves -57 and connect with individual handpieces 5.
Tubes 58-60 may extend through cabinet 1, tray arm 2 and support platform 3 to supply coolant water to handpieces 5, should handpieces 5 be mounted on platform 3 as shown in FIG. 1.
A water exhaust line 61 extends from tee 46 to an air actuated water exhaust valve 62 which may be mounted on intermediate partition 34. A drain line 63 connects the water outlet 64 of valve 62 to a collection funnel 65 connected through drain pipe 66 with the main drain or waste pipe connection in cabinet 1.
A flexible air tube 67 connects to the bottom of valve 62 through a choke 68 and connects through junction box 8 to foot controller 6. The function and operation of valves 40 and 62 (FIG. 4) connected to controller 6 by air lines 43 and 67 is discussed below.
Metering valves 55-57 are provided with knobs 69 to enable the dentist or dental assistant to individually regulate the water coolant flow rate to handpieces 5.
Foot controller 6 (FIG. 3) is similar in construction and operation to the foot controller construction shown in U.S. Pat. No. 3,359,638 and has a main air drive control valve 70, an air coolant control valve 71 and a water coolant control valve 72.
The main air flow supply enters through air supply line 73 into a manifold 74, and from manifold 74 is distributed to the air drive control valve 70 through a coupling nipple 75, to the air coolant control valve 71 through an air supply line 76, and to water coolant control valve 72 through an air supply line 77.
Control valves 71 and 72 are provided with spring biased operating levers 78 and 79 respectively, which are actuated by a cam 80 pivotally mounted at one end of a foot operated actuating arm 81. Air drive control valve 70 is actuated by a plunger 82 controlled by a pair of rollers 83 mounted on cam 80.
The flow of air from air drive control valve 70 leaves foot controller 6 through air supply line 84 for the main drive of a turbine of a dental handpiece 5. The air coolant spray for a dental handpiece leaves valve 71 through air line 85.
The air flow for actuating water coolant supply valve 40 leaves valve 72 through air line 86 and may connect with air line 43 through a coupling 87. An air exhaust line 88 leaves valve 72 and connects with air line 67 for actuating exhaust valve 62, through a check valve 89.
An air exhaust line 90 leaves air coolant control valve 71 and extends into hose 7 where its open end terminates into the atmosphere.
Coolant water supply valve 40 (FIG. 4) and water exhaust valve 62are similar and have a usual valve construction with a valve seat 91 for a lifter valve 92. When air is flowing through line 43 and inlet 42, piston 93 moves along valve bore 94 compressing spring 95 and raising lifter valve 92 from seat 91 by contacting a valve stem 96 which in turn raises floating stem 97 of lifter valve 92. Water then flows through valve 40 between lines 38 and 44 connected to water intake 39 and water outlet 45, respectively.
Springs 95, 98 and 99 return piston 93, valve stem 96 and lifter valve 92, respectively, to their at rest position (FIG. 4) when the flow of actuating air in line 43 is blocked by water coolant supply valve 72 in foot controller 6.
The dentist desiring to use a handpiece 5 to perform dental work on a patient, removes a selected handpiece 5 from its holder 100 on platform 3; for example handpiece 5 associated with supply lines 58 and 52 (FIG. 2).
The dentist moves foot control actuating arm 81 in a counterclockwise direction, (indicated by arrow A, FIG. 3) to actuate the handpiece drive turbine and to supply coolant water to the handpiece. The particular coolant water supply valve within valve block 48 controlling the flow of water to the selected handpiece also may be opened simultaneously by the counterclockwise movement of arm 81 or may be controlled by other usual actuating means.
Counterclockwise movement of arm 81 and connected cam 80 depresses valve levers 78 and 79 of control valves 71 and 72, respectively, and plunger 82 of main air drive valve as described in U.S. Pat. No. 3,359,638.
Compressed air from manifold 74 then flows through water coolant control valve 72 to inlet 42 of control valve 40 by way of air supply lines 77, 86 and 43. The compressed air flow upon entering valve 40 raises lifter valve 92 permitting coolant water to flow to selected handpiece 5 from water heater 26 through lines 28, 37, 38, 44, 47, 52 and 58.
The dentist releases foot control arm 81 upon completion of the drilling or cutting operation for which coolant water was supplied, and arm 81 returns automatically to its at rest position of FIG. 3. Spring 99 in valve 40 immediately returns lifter valve 92 to valve seat 91 blocking further flow of coolant water from line 38 through valve 40 into line 44.
In accordance with the invention the compressed air trapped in air supply lines 43 and 86 exhausts into air lines 88 and 67 through valve 72, upon closing of valve 72 by release of arm 81. The exhausted air entering valve 62 through line 67 opens valve 72 in a similar manner as described for valve 40.
The water trapped under pressure in lines 44, 47, 52 and 58 between valve 40 and handpiece 5 immediately begins to flow through open valve 62 from line 61 and tee 46 into line 63. The trapped water reverses its flow to flow away from handpiece 5 and flows through open valve 62 due to the additional pressure required to force the coolant water through a small spray opening in handpiece 5 then through the opening in valve 62 which is considerably larger than a spray opening in the handpiece. Likewise, a back pressure is created by the coolant water as it is forced through the small handpiece spray opening which helps force the trapped water through valve 62 when opened.
The control means for the individual water coolant valves in control block 48 is such that upon closing of valve 72, and valve 40, the individual valve which is open will remain open a short period of time after valve 40 closes and valve 62 opens. This may be accomplished by exhausting the air trapped in line 49 after closing of valve 71 by release of arm 81, more slowly than the trapped air in control line 43 for valve 40.
This short time delay enables sufficient water to ex haust from lines 52 and 58 so that after the valve within block 48 closes, the remaining pressure in lines 52 and 58 is insufficient to force the remaining water through a spray opening in the handpiece.
The exhaust water in line 63 empties into funnel 65 and through drain line 66 into the main waste drain for cabinet 1.
That portion of exhaust air which passes from line 43 .through valve 72 to actuate valve 62, is trapped in line 67 by check valve 89 in foot controller 6. This trapped air exhausts slowly through choke 68 thereby closing valve 62 slowly to enable the remaining trapped water in lines 44 and 47 to flow through valve 62 into line 63.
Choke 68 also muffles the sound of the air exhausting from line 67 to insure a quiet operation.
The remaining portion of air trapped in line 43 exhausts through a small relief opening 101 formed in connector 102 between air line 88 and water coolant control valve 72.
The sequence of operation described above during which the trapped water and pressure is exhausted requires a very short period of time and the operation of valves 40 and 62 and the valve of block 48 is almost simultaneous so that the exhaust operation is completed should the dentist desire to reactuate the handpiece again immediately after release of arm 81.
The pressure regulator 31 in normal operation and use of the handpieces and associated handpiece drip control system is adjusted to provide the desired pressure for water supplied to all the handpieces from valve block 48. Metering valves 55-57 also are adjusted individually to control the volume of water supplied at the selected pressure to the handpieces. This enables various types of handpieces, each of which may require a different volume of water, to be supplied with coolant water through valve block 48. Usually these adjustments, once made, need not be changed except when water supply pressure from the water main changes significantly.
Although the water is supplied to handpieces for cooling during drilling and cutting operations, the water preferably is heated to a moderate temperature to prevent shock to, the tooth being drilled or associated tooth nerve, and to eliminate variance in the coolant water temperature due to changes in the main water supply entering through line 10.
The new handpiece drip control system is very simple in construction and operation and utilizes standard components for the control valves, metering valves, pressure regulators, water and air lines, and the like. These components do not require delicate adjustments and require little, if any, servicing.
The improved apparatus and system enables the dentist repeatedly to use the dental handpieces without the water trapped within the supply line dripping from the handpiece onto the patient, dentist, equipment, etc.
Accordingly, the handpiece drip control system achieves the objectives'indicated and solves problems that have existed in the art, particularly the elimination of the heretofore handpiece coolant water drippage after use of a handpiece.
In the foregoing description, certain terms have been used for brevity, clearness and understanding but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed.
Moreover, the description and illustration of the invention is by way of example, and the scope of the invention is not limited to the exact details of the construction shown or described.
Having now described the features, discoveries and principles of the invention, the manner in which the dental handpiece drip control system is constructed, assembled and operated, the characteristics of the new system, and the advantageous, new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts, and combinations are set forth in the appended claims.
1. A dental handpiece drip control system including a dental handpiece, a water supply, a water pipeline connecting the water supply with the handpiece, first water control valve means in said water pipeline located between said water supply and said dental handpiece, means for actuating said first valve means, a junction in the water pipeline between said first valve means and said dental handpiece, drain means, a drain pipeline connecting the water pipeline at the junction with the drain means, second valve means in said drain pipeline located between the junction and the drain means, and means for actuating said second valve means, said first and second valve means being operatively interconnected whereby operation of said first valve means stopping flow of water from the water supply to the handpiece actuates said second valve means exhausting water trapped in the water pipeline between the handpiece and the first valve means through the second valve means into the drain means through the drain pipeline.
2. The system defined in claim 1 in which the actuating means for the first valve means includes a supply of compressed air, in which an air supply pipeline connects the supply of compressed air with the first valve means; and in which means are positioned in the air supply pipeline for controlling the flow of compressed air in said pipeline for actuating said first valve means between open and closed position.
3. The system defined in claim 2 in which the actuating means for the second valve means includes an air exhaust pipeline, in which said air exhaust pipeline connects with the air supply pipeline and said second valve means, and in which the flow of compressed air trapped in the air supply pipeline when the first valve means is in closed position actuates the second valve means to open position through said air exhaust pipeline.
4. The system defined in claim 3 in which check valve means is connected in the air exhaust line between the first and second valve means to trap exhaust air between the second valve means and the check valve means.
5. The system defined in claim 4 in which choke means is connected with the air exhaust line between the second valve means and the check valve means.
6. The system defined in claim 1 in which water heater means is connected in the water pipeline between the first valve means and the main water supply.
7. The system defined in claim 1 in which a selector valve block means is connected in the water pipeline between the junction and the handpiece, in which a plurality of branch water coolant lines extend from the valve block means, and in which control means connect with said valve block means for selectively connecting the supply of water with dental handpieces con-' nected to each of the branch lines.
8. Dental handpiece drip control system including a dental han dpiece, a water supply, a water pipeline connecting the water supply with the handpiece, first water control valve means in said water pipeline located between the water supply and the dental handpiece, a
junction in the water pipeline between the first valve line between the first valve means and the compressed air supply, and an air exhaust line: connecting the control means and the second valve means whereby the compressed air trapped in the compressed air supply line between the first valve means and the control means when the first valve means is closed exhausts into the exhaust air line through the control means and opens the second valve means to enable the water trapped between the handpiece and the first valve means to flow through the second valve means from the junction into the drain means through the water ex haust line.