Dental cleaning and gum massaging device

Sept. 9, 1969

M. A. POWERS

3,465,751

DENTAL CLEANING AND GUM MASSAGING DEVICE

Filed June 21, 1966 4 Sheets-Sheet 1

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Sept. 9, 1969

M. A. POWERS

3,465,751

DENTAL CLEANING AND GUM MASSAGING DEVICE

Filed June 21, 1966

Sheets-Sheet 2

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ΙΘ2

ATTORNEYS

Sept. 9, 1969

M. A. POWERS

3,465,751

DENTAL CLEANING AND GUM MASSAGING DEVICE

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INVENTOR

MILTON A. POWERS

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Sept. 9, 1969

M. A. POWERS

3,465,751

DENTAL CLEANING AND GUM MASSAGING DEVICE

Sheets-Sheet 4

Filed June 21, 1966

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United States Patent Office

3,465,751

Patented Sept. 9, 1969

3,465,751

DENTAL CLEANING AND GUM MASSAGING DEVICE

Milton A. Powers, 655 Bedford Lane, Grosse Pointe Park, Mich. 48230 Filed June 21, 1966, Ser. No. 559,173 Int. Cl. A61c 17/02; A61h 9/00; A61m 11/02

U.S. Cl. 128—66 20 Claims

ABSTRACT OF THE DISCLOSURE

A dental cleaning and gum massaging device particularly adapted to the form of an attachment for a power toothbrush or other drive device having a motor driven 15 stem. A nozzle forming a part of the device and driven in a continuous path by the motor driven stem is connected to a source of pressurized liquid for directing a jet of the liquid onto teeth and gum surfaces to be treated. The dental cleaning and gum massaging device may be 20 constructed for use in place of the usual power driven toothbrush element or it may include a toothbrush element for brushing the teeth as the teeth and gum surfaces are simultaneously treated by the jet of liquid. In the latter case, the nozzle may be formed in the toothbrush stem 25 or it may be mounted on the toothbrush stem.

This invention relates to dental cleaning and gum 30 massaging devices and more particularly to the type of oral hygiene device which utilizes liquid jets for stimulating gum tissues and for cleaning the teeth and adjacent tissues.

Prior to this invention, devices have been proposed 35 for directing high velocity jets of liquids against teeth surfaces and other regions to be treated or cleaned. Examples of such oral hygiene devices are described in U.S. Letters Patent No. 3,227,158 issued to John W. Mattingly on Jan. 4, 1966, and U.S. Letters Patent No. 3,225,759 issued to Μ. E. Drapen et al. on Dec. 28, 1965.

While certain prior liquid jet cleaning and gum stimulating devices have met with some degree of success, difficulties have been encountered in providing an apparatus which is inexpensive and simple as well as being efficient and easy to manipulate effectively by non-technical users. In general, experience has shown that prior efforts to improve the efficiency and ease of manipulation of prior liquid jet devices have resulted in inordinately expensive and relatively complicated structures.

Accordingly, it is a major object of this invention to provide a novel liquid jet dental cleaning and gum stimulating device which is inexpensive and simple in construction as well as being highly effective and easy to manipulate for efficiently cleaning teeth and stimulating gum tissues.

Another object of this invention is to provide a novel liquid jet dental cleaning and gum stimulating device wherein motor driven motion is imparted to a jet producing nozzle during ejection of the liquid jet onto the teeth and gum surfaces being treated. The motion imparted 60 to the nozzle may be reciprocatory, oscillatory about a longitudinal axis, or orbital.

According to this invention, the motor driven motion of the nozzle directs the jet into the spacing between adjacent teeth and especially around the gum line to more efficiently dislodge food particles in comparison with the manually manipulated jet movement required with prior art devices. In addition, the impingement of the moving jet on gum surfaces provides an improved stimulation of the tissues. Such gum massage is especially important and is recommended for adults to prevent the gum line from receding.

A further object of this invention is to provide a novel liquid jet dental cleaning and gum stimulating device which is in the form of an attachment for quick and easy mounting on the motor driven output of an electric tooth₅ brush.

Another important object of this invention is to provide a novel dental cleaning and gum stimulating device wherein a liquid jet-producing nozzle is carried by a toothbrush attachment for an electric or other form of motor driven toothbrush device. According to this aspect of the present invention the nozzle is located in the proximity of the toothbrush bristles so that brushing and liquid jet impingement action is achieved simultaneously.

Still another object of this invention is to provide a novel liquid jet dental cleaning and massaging device with a uniquely simplified pressure regulator for maintaining an easily selected, steady liquid jet pressure.

Another important object of this invention is to provide a novel pump for a liquid jet dental cleaning and massaging device.

A further object of this invention is to provide a novel liquid jet dental and massaging device having a special container arrangement for receiving mouth washes or other solutions to be ejected as a jet onto the surfaces to be treated.

Further objects will appear as the description proceeds in connection with the appended claims and annexed drawings wherein:

FIGURE 1 is a side elevation of a dental cleaning and massaging device constructed according to one embodiment of this invention and adapted for detachably mounting on the oscillatory drive shaft of a conventional electric toothbrush motor;

FIGURE 2 is an enlarged, fragmentary section taken substantially along lines 2—2 of FIGURE 1;

FIGURE 3 is a partially sectioned side elevation illustrating a modified dental cleaning and massaging device for mounting on an electric toothbrush motor of the reciprocating type;

FIGURE 4 is an enlarged, fragmentary plan view illustrating details of the motor attachment end fitting of the device shown in FIGURE 3;

FIGURE 5 is a fragmentary side elevation illustrating another embodiment of this invention wherein a uniquely 45 constructed pump is employed to deliver liquid under pressure to the jet nozzle;

FIGURE 6 is an enlarged partially sectioned view illustrating details of the pump shown in FIGURE 5;

FIGURE 7 is a partially sectioned, fragmentary eleva50 tion illustrating a modification of the device shown in FIGURES 5 and 6;

FIGURE 8 is a partially sectioned side elevation of still another embodiment of this invention;

FIGURE 9 is an enlarged, longitudinal section of 55 the toothbrush and jet nozzle attachment shown in FIGURE 8;

FIGURE 10 is a fragmentary plan as viewed from lines 10—10 of FIGURE 9;

FIGURE 11 is a fragmentary, longitudinal section illustrating a modified form of the attachment shown in FIGURES 9 and 10;

FIGURE 12 is a partially schematic longitudinal section illustrating a water powered engine and pump for delivering liquid under pressure to jet nozzles shown in 65 the previous embodiments;

FIGURE 13 is a partially schematic, partially sectioned view illustrating a further embodiment wherein a specially constructed pressure regulator is employed to control the pressure of the liquid jet; and

FIGURE 14 is a partially sectioned side elevation illustrating another modified form of the attachment shown in FIGURES 9 and 10.

3,465,751

Referring now to the drawing and more particularly to FIGURES 1 and 2, the reference numeral 20 generally designates a liquid jet dental cleaning and gum massaging device which is constructed according to the principles of this invention for attachment to an electric toothbrush motor drive assembly 22. Motor assembly 22 may be of any conventional, suitable construction and is shown in this embodiment to comprise a generally tubular shaped, plastic casing 24 which houses a rechargeable, battery operated, electric motor 25, and an unshown transfer and gear reduction mechanism. The unshown transfer and gear reduction mechanism drive connects the motor to a drive shaft 26 extending coaxially beyond the forward end of casing 24. The internal transfer, and gear reduction parts are not illustrated since they are all of suitable, conventional form.

In this embodiment, shaft 26 is rotatably supported in casing 24 and is oscillated about its longitudinal axis between angularly spaced apart, fixed limits. This type of oscillatory motion is commonly used in many conventional electric toothbrushes for imparting a swinging movement to the toothbrush to simulate the preferred updown movement of the toothbrush brisles relative to the user’s teeth. As shown in FIGURE 1, a thumb-operated switch 28 is mounted near the forward end of casing 24 and is actuatable to control energization of the motor 25.

Device 20, which in in the form of an attachment, is adapted to be detachably mounted on shaft 26 in place of the usual toothbrush and is shown to comprise a jetproducing nozzle 30 which is integrally joined to a straight, tubular conduit section 32. Nozzle 30 preferably extends at an oblique angle with respect to the longitudinal axis of section 32 to enable the user to more easily direct the liquid jet onto the teeth and gum surfaces to be treated. Both nozzle 30 and conduit section 32 may be moulded from a suitable plastic. Conduit section 32, which is essentially axially aligned with the longitudinal axis of casing 24, is sufficiently stiff to provide a relatively firm support for nozzle 30.

As best shown in FIGURE 2, the rearward end of formed in conduit section 32 adjacent to its bevelled end. with a snug fit in a bore 34 which is formed in a fitting 36. A resilient O-ring 38 mounted in bore 34 is seated in an annular outwardly opening groove 40 which is formed conduit section 32 adjacent to its bevelled end. O-ring 38 provides a fluid tight seal to prevent leakage of liquid between the cylindrical smooth wall surface of bore 34 and the external periphery of conduit section 32.

The fit of conduit section 32 in bore 34 is sufficiently snug to prevent inadvertent rotational or longitudinal displacement of section 32 relative to fitting 36, but is not so tight as to prevent the user from turning section 32 to selectively position nozzle 30. For this purpose a suitable wheel 42 is coaxially fixed on conduit section 32 adjacent to the forward end of fitting 36 and is adapted to be manipulated by the user to turn nozzle 30 to its most effective position. By exerting a manual effort, conduit section 32 may be pulled out of bore 32 if it is desired to detach it from fitting 36.

With continued reference to FIGURE 2, device 20 is provided with a cylindrical end fitting 44 which is fixed to the rearward end of fitting 36 in essentially axial alignment with bore 34. Fitting 44 is coaxially formed with a blind bore 46 which is adapted to slidably receive the protruding end of shaft 26. Advantageously, the wall of bore 46 may be formed with equiangularly spaced apart, longitudinally extending, internal ribs 48 which grip the periphery of shaft 26 to avoid inadvertent axial displacement of device 20 relative to shaft 26. Fittings 36 and 44 are both preferably made from relatively hard plastic.

As best shown in FIGURE 2, a cylindrical pin 50 is fixed to shaft 26 and radially extends through a rearwardly opening slot 52 which is longitudinally formed in the rearward end of fitting 44. The width of slot 52 pref erably is slightly smaller than the diameter of pin 50. As a result, the insert of pin 50 spreads and firmly grips the side edges of slot 52 to provide a secure, non-rotatable drive connection between fitting 44 and shaft 26.

From the foregoing description, it is clear that energization of motor 25 imparts oscillatory movement to nozzle 30 about the rotational axis of shaft 26 through the drive connection provided by shaft 26 and pin 50.

To detach device 20 from motor assembly 22, it is merely necessary to pull it relative to casing 24 to remove shaft 26 from bore 46 and pin 50 from slot 52. Attachment of device 20 is equally as simple since it is only necessary to angularly orient slot 52 with pin 50 and to then slide fitting 44 onto shaft 26.

Still referring to FIGURES 1 and 2, fitting 36 is formed with a cross bore 56 (FIGURE 2) which normally intersects the inner end of bore 34. A tubing assembly 58 connecting bore 56 to a water faucet 60 comprises a suitable female fitting 62 which is fixed to a flexible tube 64. Fitting 62 is securely mounted on a sleeve-shaped male fitting 66 (FIGURE 2) which is fixed to fitting 36 in bore 56.

The opposite end of tube 64 preferably is integrally joined to a special male fitting 68. Fittings 62 and 68 and tube 64 preferably are made from plastic or other suitable elastically deformable material.

As shown in FIGURE 1, fitting 68 comprises a diametrically enlarged sleeve section 70 which is adapted to be inserted with a tight, snug fit into the mouth of faucet 60. Section 70 preferably is slightly larger than the internal flow passage 72 which is formed in faucet 60 inwardly of its mouth. As a result, section 70 is deformed slightly when inserted into passage 72 to more tightly grip the internal wall surface of faucet 60.

Tube 64, which is appreciably smaller in diameter than sleeve section 70, extends coaxially into the forward end of section 70 and is integrally joined thereto by a flexible transition section 76. Section 76 is formed with an axially extending annular portion 78 which is concentrically disposed between the forward end of sleeve section 78 and the rearward end of tube 64. Annular portion 78 is integrally joined at opposite ends to the rearward end of tube 64 and to the forward end of sleeve section 70 by curved annular portions 80 and 82 respectively. Portion 80 extends essentially radially between the rearward end of tube 64 and portion 78, and portion 82 extends essentially radially between the forward end of sleeve section 70 and portion 78. Portions 80 and 82 are sufficiently flexible to allow limited axial displacement of tube 64 relative to sleeve section 70. Fitting 68 is thus provided with a cupshaped configuration having a bottom in which an annular axially opening groove 84 is formed in encircling relation to the end of tube 64.

When inserted into the mouth of faucet 60, section 76 is. sufficiently stiff to hold the rearward end of tube 64 within sleeve section 70 as shown in FIGURE 1. Water delivered through passage 72 fills sleeve section 70 and groove 84 and flows through tube 64. The pressure of the water within sleeve section 70 acts radially against the internal periphery of section 76 and axially against the axially facing internal surfaces of fitting 68. Sleeve section 76, in accordance with this invention, is made sufficiently long as to provide an internal peripheral surface which is appreciably greater in area than that of the internal axially directed surfaces. The water pressure will therefore act in a radial direction over an appreciably greater surface to cause sleeve section 70 to grip the interior faucet surface with sufficient force to oppose and prevent axial outward displacement of fitting 68 for pressures normally encountered in household use. As the water pressure is increased with increased flow, sleeve section 70 is more tightly pressed against the internal periphery of faucet 60 to prevent leakage and to keep fitting 68 from being blown out of the faucet.

3,465,751

To control delivery of water to nozzle 30, a valve 90 (see FIGURE 2) is advantageously provided for and is shown to comprise a stem 92 which is rigid with a cylindrical valve closure member 94. Closure member 94 is slidably received in a cylindrically smooth walled, through bore 96. Bore 96 is formed in fitting 36 along an axis that normally intersects the axis of bore 34. The region at which bore 96 intersects bore 36 is located axially between the intersection of bores 56 and 34 and the inner end of conduit section 32.

Still referring to FIGURE 2, closure member 94 is provided with a through port 109 which, when aligned with bore 34, provides fluid communication between bore 56 and nozzle 30. Closure member 94 is normally biased by a coiled spring 102 to a position where it blocks liquid flow through bore 34.

Spring 102 reacts against a plug 104 which is threaded into one end of bore 96. Stem 92 slidably extends through a collar 106 which is threaded into the opposite end of bore 96. A button 108 is fixed to the outer end of stem 92 to facilitate manual axial displacement of closure member 94 from its illustrated closed position to its opened position.

When it is desired to use device 20, fitting 68 is inserted into faucet 60 in the manner previously described and the faucet valve is opened and adjusted to a position where the water pressure provides the discharge jet with a comfortable, but sufficient force to dislodge food particles and to stimulate circulation of blood in the gum tissues. The user then inserts nozzle 30 into his mouth, actuates switch 28 to energize the motor in casing 24 and depresses button 108. A jet of liquid thus will be ejected from nozzle 30 which is being oscillated about the longitudinal axis of shaft 26. As a result, the liquid jet will sweep back and forth over the teeth and gum surfaces being treated. The water jet will therefore impinge at different angles onto the surfaces being treated to more effectively dislodge food particles in spaces between the teeth. In addition, the impingement of the oscillating water jet on gum surfaces provides an improved stimulation of the gum tissue since the jet will strike the gum surfaces at a rapidly and continuously changing angle. In this embodiment, the discharge of water from nozzle 30 is continuous and at an essentially uniform pressure.

Preferably, the unshown gear reduction mechanism ir casing 24 imparts motion to nozzle 30 at the rate of 1030 oscillations per second. This range has been found to be most effective for dislodging food particles, cleaning teeth surfaces, and stimulating gum tissue.

In the embodiment shown in FIGURES 3 and 4, the dental cleaning and massaging device of this invention is modified for attachment to a reciprocable type of electric toothbrush motor assembly 120. To the extent that this embodiment is the same as the previous embodiment, like reference characters have been applied to designate like parts.

Motor assembly 120 may be of any suitable conventional form and is shown in FIGURE 3 to comprise a generally tubular shaped casing 122 which contains the unshown electric motor and an unshown transfer and gear reduction mechanism. The transfer and gear reduction is of known construction for drive connecting the unshown electric motor to reciprocate a power output member 124 along an axis that is coaxial with casing 122. A flexible bellows 126 has a skirt portion peripherally secured to the forward end of casing 122. Bellows 126 peripherally surrounds member 124 to seal the casing space containing the motor, gear, and transfer mechanism parts. Since these parts are conventional and are connected in a known manner, they have not been illustrated. A switch 127 mounted on casing 122 is selectively actuatable to control energization of the unshown motor which preferably is of the rechargeable, battery operated tvpe.

Still referring to FIGURE 3, member 124 is coaxially formed with an axially outwardly opening socket 128.

Socket 128 is provided with an essentially rectangular cross-section and is adapted to slidably receive an end fitting 130 of similar configuration.

Fitting 130, as shown in FIGURES 3 and 4, is made from a suitable plastic and is fixed to the rearward end of fitting 36 in place of fitting 44. The shank of fitting 130, which is tapered towards its rearward end and which is provided with a rectangular cross-section, is formed with a longitudinally elongated aperture 132 to integrally define a relatively thin, elongated latching arm 134.

Arm 134 is supported in cantilever fashion at its forward end and has, at its rearward end, a laterally extending projection 136 which is adapted to matingly seat in an opening 138. Opening 138 is formed in one of the side walls of member 124 which defines socket 128.

Since fitting 130 is made from an elastically deformable material, arm 134 may be flexed at its juncture with the forward fitting body portion indicated at 140. Projection 136 normally extends slightly beyond the upwardly facing surface of fitting 130 shown in FIGURE 3 and can be depressed downwardly by application of a relatively light pressure to swing arm 134 about its junction with body portion 140. Thus, when fitting 130 is axially inserted into socket 128, the tip of projection 136 slidably engages the socket side wall and is pressed downwardly as viewed from FIGURE 3. When fitting 130 is pushed sufficiently far into socket 128, projection 136 comes into alignment with and resiliently snaps into opening 138 to latch fitting 130 to member 124. Engagement of projection 136 with the edges defining opening 138 prevents relative axial displacement between member 124 and fitting 130. Relative rotation between fitting 130 and member 124 is prevented owing to the noncircular configuration of socket 128 and the mating crosssectional configuration of the shank of fitting 130.

From the foregoing description it is clear that device 20 is secured to member 124 and is thus reciprocated thereby when the unshown motor in casing 122 is energized. Nozzle 30 is thus reciprocated along a path that is parallel to the longitudinal axis of member 124 with the result that the liquid jet ejected from nozzle 30 rapidly sweeps back and forth over the teeth and gum surfaces being treated. The rate of reciprocation imparted to nozzle 30 preferably is in the range of 10-30 oscillations per second. The stroke of reciprocation is relatively short and may be the same as that provided in reciprocable power driven toothbrushes of conventional form.

To detach device 20 from member 124, arm 134 is integrally formed with a raised land 142 which is disposed axially beyond the forward end of socket 128 when fitting 130 is secured to member 124. The user applies finger pressure to land 142 to depress arm 130 to a position where projection 136 clears opening 138. This action unlatches fitting 130 from member 124, allowing it to be freely pulled out of socket 128.

FIGURES 5 and 6 illustrate another embodiment of this invention wherein a modified dental cleaning and massaging device 150 is mounted on a toothbrush 152. Toothbrush 152 is adapted to be attached to an electric motor assembly 154 which is the same as that shown in FIGURES 3 and 4. Accordingly, like reference characters have been applied to designate the parts of assembly 154.

As best shown in FIGURE 6, toothbrush 152 is provided at its forward end with the usual bristles 158 which are embedded at their inner ends in a stem 160. Stem 160 may be formed from any suitable plastic material and has a shank section 161 which is adapted to be slidably received in socket 128.

Shank section 161 is identical to fitting 130, with like reference characters suffixed by the letter a being applied to designate like elements. Shank section 161 is thus detachably secured to member 124 by latching projection 136α in opening 138 in the same manner as described

3,465,751 in connection with the embodiment of FIGURES 3 and 4. Detachment of toothbrush 152 is accomplished by depressing land 142α and pulling the toothbrush forwardly until shank section 161 clears socket 128.

The foregoing toothbrush construction and attachment to member 124 is conventional. Accordingly, description of further details is not believed to be essential for an understanding of this invention.

As best shown in FIGURE 6, device 150 comprises a nozzle 162 which is integrally joined to a conduit section 164. Conduit section 164 is curved to dispose nozzle 162 beyond the forward end of stem 160 on which bristles 158 are mounted. As shown, nozzle 162 is oriented to direct a liquid jet along a path that is essentially parallel to bristles 158. The liquid jet impinges against the teeth or gum surfaces that are immediately adjacent to the surfaces engaged by bristles 158.

Still referring to FIGURE 6, conduit section 164 integrally joins nozzle 162 to a hollow cylinder 166 which forms a part of a reciprocating pump 168. Pump 168 is provided with a hollow, tubular shaped piston 170 which is slidably received with a close fit in cylinder 166 and which is formed by the end of a liquid delivery tube 172.

Cylinder 166 is seated against the flat back of stem 160 and is securely fixed thereto by any suitable means such as a band 174. Alternatively, cylinder 166 may be cemented to stem 160 by a suitable adhesive. Both piston 170 and cylinder 166 extend longitudinally of stem 160 and along an axis that is parallel to the axis along which member 124 is reciprocated.

Tube 172 extends rearwardly along stem 160 and is securely fixed to casing 122 by a clamp and screw assembly 176. The rearward end of tube 172 is provided with a fitting 178 (see FIGURE 5) which may be the same as fitting 68 for detachably connecting tube 172 to a water faucet. Advantageously, a valve 180 may be mounted on casing 122 to control fluid communication between the faucet end of tube 172 and nozzle 162. Valve 180 may be of any suitable construction and is shown to have an operating stem member 182 which is manually depressible to provide fluid communication between the faucet end at fitting 178 and nozzle 162.

With continued reference to FIGURES 5 and 6, the integral part forming nozzle 162, conduit section 164, and cylinder 166 may be formed from any suitable plastic material. The section of tube 172 extending from clamp and screw assembly 176 to the rearward end of piston 170 is sufficiently stiff that piston 170 is held axially stationary relative to casing 122. Energization of the motor in casing 122 therefore reciprocates toothbrush 152 to slide cylinder 166 back and forth over piston 170.

As shown in FIGURE 6, the forward end of tube 172 is crimped to provide an annular inwardly extending shoulder 184. Shoulder 184 defines a restricted flow orifice entering piston 170 and provides an axially forwardly facing valve seat. A valve comprising a ball 186, which is loosely received in the rearward end of piston 170, is adapted to seat against the seating surface defined by shoulder 184 to block fluid communication between the interior of cylinder 166 and the source of liquid supply. Circumferentially spaced apart indentations 188 are formed in piston 170 axially forwardly of shoulder 184 to limit forward, unseating movement of ball 186 on the intake stroke of pump 168.

When the motor in casing 122 is energized to impart reciprocation to toothbrush 152, cyinder 166 is reciprocated relative to piston 170 which, as previously mentioned, is held stationary relative to casing 122. As cylinder 166 moves forward on the pump intake stroke, the volume within cylinder 166 expands to correspondingly decrease the liquid pressure therein. As a result, the pressure exerted by liquid delivered through tube 172 unseats ball 186 to allow the liquid to flow through piston 170 and into cylinder 166. On the reverse or discharge stroke of cylinder 166 the internal cylinder volume decreases, causing an increase in liquid pressure which urges ball 186 into engagement with the seating surface on shoulder 184. As a result, fluid communication between the interior of cylinder 166 and the liquid supply source at fitting 178 is blocked. Continued movement of cylinder 166 on the discharge stroke will thus pressurize the trapped liquid to force it out of nozzle 162 in the form of a jet.

To operate the dental cleaning and massaging device shown in FIGURES 5 and 6, the user merely connects fitting 178 to a faucet or other liquid source, actuates switch 127 to energize the drive motor in casing 122 and depresses operating stem 182. Pump 168 operates to discharge liquid through nozzle 162 which is reciprocated with toothbrush 152. The liquid jet ejected from nozzle 162 will therefore sweep back and forth along the teeth and gum surfaces immediately adjacent to the surfaces engaged by bristles 158. By employing pump 168, the source of liquid is not required to have a high jet forming pressure. Ftting 178 therefore may be connected to a receptacle adapted to contain a mouthwash or other solution at essentially atmospheric pressure and having a liquid head which is just sufficient to deliver the liquid to cylinder 166. When fitting 178 is connected to a water faucet, the faucet may be adjusted to limit the water pressure. By using a relatively low water faucet pressure, leakage is substantially avoided and there is less likelihood that fitting 178 will be blown out of the faucet.

To smooth out any pulsations that may result from the operation of pump 68, a relatively small, flexible bulb 200 (see FIGURE 7) may be secured to the forward end of cylinder 166. Bulb 200 may be made of any suitable material such as rubber or the like and provides a pulsation dampening chamber 202 which is in constant fluid communiaction with the cylinder chamber space located axially beyond piston 170 when the latter is in its foremost position. Owing to its chamber capacity, bulb 200 effectively absorbs any pulsations produced by operation of pump 168 to provide a relatively steady jet flow through nozzle 162.

In the embodiment illustrated in FIGURES 8-10, a modified toothbrush 209 is provided for connection to motor assembly 154. Toothbrush 209 is the same as toothbrush 152 except that a fluid flow passage 210 is formed in stem 160. Passage 210 is normally intersected by axially spaced apart bores 212 and 214. Bore 212 terminates in a nozzle 216 which is disposed medially of stem 160 and centrally of the group of bristles 158 adjacent to the forward end of stem 160. The opposite end of bore 212 at the back side of stem 160 is threaded to receive a plug 218.

Nozzle 216, as shown in FIGURES 9 and 10, is surrounded by bristles 158 and is oriented to eject a liquid jet along a path that is parallel to the toothbrush bristles and essentially perpendicular to the longitudinal axis of stem 160.

Bore 214, as best shown in FIGURE 9, is disposed rearwardly of bore 212 and receives a sleeve 220 on which a female fitting 222 is mounted. A flexible liquid delivery tube 224 is fixed at opposite ends to fitting 222 and to the discharge port of a suitable pump 226. Tube 224 optionally may contain a flow control valve 228 which conveniently is mounted on casing 122. Valve 228 may be the same as valve 180.

The inlet port of pump 226 is adapted to be detachably connected to faucet 60 by a suitable tube and fitting assembly 230. It will be appreciated that pump 226 optionally may be omitted and tube 224 connected directly to faucet 60.

As previously explained, toothbrush 209 is reciprocated by energizing motor 25 in casing 122. Concomitantly, pump 226 is operated by a suitable unshown prime mover to deliver liquid under pressure through tube 224 and passage 210 to nozzle 216. Liquid will thus be ejected

3,465,751 through bristles 158 and onto the teeth and gum surfaces being contacted by the bristles.

As toothbrush 209 is reciprocated, bristles 158 are advanced back and forth over the surfaces being treated and the liquid jet ejected from nozzle 216 simultaneously sweeps back and forth over the same surfaces. Thus, a highly effective cleaning and gum massaging action is obtained by the simultaneous engagement of bristles 158 and impingement of the liquid jet on the same surfaces.

To impart swinging or oscillatory movement to the combined toothbrush and liquid jet structure shown in FIGURE 9' instead of reciprocating motion, it is clear that the attachment fitting may be replaced with a fitting 230 (see FIGURE 14) which is esentially the same as fitting 44. Thus modified, the toothbrush may be detachably and non-rotatably connected to shaft 26 of motor assembly 22. When the motor 25 in casing 24 is energized, therefore, bristles 158 and nozzle 216 will be oscillated about the longitudinal axis of shaft 26. As a result, bristles 158 and the liquid jet being ejected from nozzle 216 will sweep between fixed, angularly spaced apart limits with essentially up and down strokes.

In the modified embodiment shown in FIGURE 11, stem 160 is formed with a short integral extension 240 which projects forwardly beyond bristles 158. Passage 210 extends forwardly through extension 240 and normally intersects a transverse bore 242. Bore 242 is formed in extension 240 and terminates on the bristle side of stem 160 in a nozzle 244. The opposite end of bore 242 is threaded to receive a plug 246. The forward open end of passage 210 is also closed by a plug 248.

From the foregoing description it will be appreciated that liquid delivered under pressure through passage 210 is ejected through nozzle 244 in the form of a jet. This liquid jet will be parallel to, but displaced slightly forwardly of bristles 158 similar to the nozzle structure shown in FIGURES 5 and 6.

FIGURE 12 schematically illustrates a suitable pump and prime mover assembly 260 which may be adapted for use in any of the embodiments shown in FIGURES 1-4 and 8-11. As shown, assembly 260 comprises a water powered, reciprocating engine 262 for driving a pump 264.

Engine 262 is essentially the same as a typical steam engine and comprises a cylinder 266 in which a piston 268 is slidably mounted for reciprocation. A casing section 270, which is rigid with cylinder 266, defines a chamber 272 having an inlet port 274 and an outlet port 276. Port 274 is connected by a suitable conduit 278 to a source of water under pressure such as faucet 60. Port 276 is connected by a suitable unshown conduit to discharge exhausted water into the basin.

A D-slide valve 280 mounted in chamber 272 controls liquid flow through a pair of operating ports 282 and 284 which are formed through cylinder 266. Valve 280 is connected by a suitable motion transmitting linkage 286 to a piston rod 288 which is fixed to piston 268.

In operation, water is delivered under pressure to chamber 272 and alternately through ports 282 and 284 under the control of valve 280. Ports 282 and 284 communicate with the piston containing cylinder chamber axially on opposite sides of piston 268. Thus, delivery of water under pressure through port 284 advances piston 268 from left to right as viewed from FIGURE 12. At this stage, valve 280 is positioned to establish fluid communication between port 282 and port 276, thus exhausting water on the right side of piston 268 to the basin.

When piston 268 reaches its right-hand limit, valve 280 reverses the connections of ports 282 and 284, causing water to flow into the cylinder chamber through port 282 and allowing the water on the left side of piston 268 to discharge through port 284 as the piston is advanced from right to left.

¹⁰

Still referring to FIGURE 12, pump 264 comprises a piston 292 which is connected to rod 288 and which is slidably mounted in a cylinder 294. Pump 264 has an inlet port 296 which is connected by a conduit 298 to faucet 60. The pump outlet port 300 is adapted to be connected to supply liquid under pressure to the nozzle of the dental cleaning and massaging device.

Pump 264 is of conventional construction and is shown in this embodiment to have a pair of operating valves 302 and 304 which control fluid flow to and from cylinder 294 in the usual manner.

According to this invention, the area of piston 294 is considerably smaller than the area of piston 268. As a result, the pressure of liquid discharged through port 300 will be considerably greater than the pressure in cylinder 266. An engine piston area to pump piston area ratio of about 4:1 is preferred. With this construction, a relatively high jet-forming nozzle pressure is thus obtained by using a relatively low water pressure to drive engine 262. Problems involved in maintaining a tight, leakage-free connection at faucet 60 are thus avoided.

FIGURE 13 illustrates a novel pressure regulator 310 which is adapted to be connected between nozzle 30¹ and faucet 60. According to this invention, regulator 310 comprises an elastically deformable housing 312 which defines a fluid pressure regulating chamber 314. Housing 312 be made from any suitable plastic or elastomeric material and is formed with opposed side walls having fluid inlet and outlet ports 316 and 318. Inlet port 316 is connected by a suitable flexible tubing 320 to faucet 60, and outlet port 316 is connected by a flexible tube 322 to nozzle 30.

As shown, housing 312 is formed with a generally rectangular configuration and has top and bottom walls 324 and 326. Bottom wall 326 is formed with a by-pass port 330 which is connected by a suitable, flexible tubing 332 to the water basin indicated at 334. A throttle valve 336 adapted to engage a seat around port 330 is selectively manipulatable to control the flow rate through the by-pass connection provided by tubing 332.

Valve 336 is rigid with a valve operating stem 338 which is threaded through a tapped bore 340. Bore 340 is formed in a boss portion 342 which is integral with wall 324. The axis of bore 340 aligns with the axis of port 330 as shown.

In operation of the pressure regulator construction thus far described, water is delivered through tubing 320 to fill chamber 314, and valve 336 is adjusted to provide the desired pressure for the jet ejected from nozzle 30. Excess water in chamber 314 flows through port 330 and is discharged to basin 334. If the pressure of water entering chamber 314 increases, walls 324 and 326, being formed from elastically deformable material, are deformed or bulged outwardly. This wall movement imparts relative axial displacement to valve 336 and port 330 in opposite directions. As a result, the fluid flow area through port 330 is increased to allow water to be bypassed to basin 334 at an increased flow rate. This increased flow rate reduces the water volume in chamber 314 to correspondingly reduce the water pressure therein.

As the water pressure in chamber 314 decreases, walls 324 and 326 flex inwardly towards each other with the result that valve 336 resumes its orginally adjusted position. The water pressure at nozzle 30 is thus maintained substantially constant to provide a steady jet stream.

In the event the faucet water pressure decreases, walls

324 and 326 flex towards each other to move valve 336 closer to its valve seat and to thereby throttle the water flowing through port 330. The pressure in chamber 314 therefore increases causing walls 324 and 326 to flex outwardly with the result that valve 336 tends to resume its originally adjusted position.

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Optionally, a thermostatic bimetal valve 344 may be mounted in chamber 314 for controlling flow of water through port 318. Valve 344 is normally open and closes when its bimetal element senses a predetermined increase in the temperature of water entering chamber 314. If the ₅user should inadvertantly adjust the hot and cold water faucet valve or valves to provide a hot mixture which would be uncomfortable or cause scalding, valve 344 responds to block fluid flow through port 318. When this condition occurs, the continued delivery of water to chamber jq 314 increases the pressure therein to flex walls 324 and 326 outwardly and thereby increase the flow rate of water by-passed to basin 334 in the manner previously described.

The invention may be embodied in other specific forms without departing from the spirit or essential character- 15 istics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and 20 range of equivalency of the claims are therefore intended to be embraced therein.