US 3909867 A
A rotary toothbrush comprises a hand held housing and a toothbrush interchangeably mounted on a rotary shaft journalled in the housing. The housing has a chamber wherein a turbine wheel is mounted for rotating the shaft when water under pressure is supplied to the housing chamber. A manually operable control is mounted on the housing to drive the wheel in either direction or to stop it, and a water ejector means in the housing chamber causes a pressure reduction in the chamber between the turbine wheel and a water outlet for facilitating drainage of water. Channels in the shaft supply rinsing water from the housing chamber to the brush.
Claims available in
Description (OCR text may contain errors)
1 States 1191 1111 3,909,867
Hogsell Oct. 7, 1975 HYDRAULIC PRESSURE DRIVEN ROTARY TOOTHBRUSH Primary Examiner-Edward L. Roberts  Inventor: Gunnar Hogsell, Boplatsvagen 6, Attorney Agent or firm-min Kelman S-291 65 Kristianstad, Sweden  Filed: Sept. 13, 1974  ABSTRACT  Appl. No.: 505,986
A rotary toothbrush comprises a hand held housing  Foreign Application Priority Dat and a toothbrush interchangeably mounted on a rotary Sept. 20, 1973 Sweden 7312796 Shaft journaued in the housing The housing has a chamber wherein a turbine wheel is mounted for ro- 52 us. (:1. 15/24; 32/26; 415/503 e the Shaft when Water under Pressure is Supplied 51 11m. 01. A61C 17/02; A46B 13/06 the housing ehemher- A manually Operable Control  Field of Search l5/22 R, 23, 24 28 29, is mounted on the housing to drive the wheel in either /97 32/26, 27, 28, 59; 415/503 direction or to stop it, and a water ejector means in the housing chamber causes a pressure reduction in  References Cited the chamber between the turbine wheel and a water UNITED STATES PATENTS outlet for facilitating drainage of water. Channels in the shaft supply rinsing water from the housing cham- 3,046,585 7/1962 Ledingham et al. 15/24 her to the brush 3,553,758 l/l97l Wood 15/24 FOREIGN PATENTS OR APPLICATIONS 15 Claims 10 Drawing Figures 503,568 12/1954 Italy 415/503 Oct. 7,1975 Sheet 1 of 4 3,909,867
US. Patent US. Patent Oct. 7,1975 Sheet 2 of4 3,909,867
US. Patent Oct. 7,1975 Sheet 3 of4 3,909,867
US, Patent 0012. 7,1975 Sheet4 of4 3,909,867
HYDRAULIC PRESSURE DRIVEN ROTARY TOOTHBRUSH The present invention relates to improvements in a hydraulic pressure driven rotary toothbrush.
Conventional toothbrushes, while simple and convenient, do not meet the requirements of modern dental hygiene. Efficient dental cleansing requires brushing to be performed in such a manner as to prevent bacteria and food particles from being pressed into pockets between the gum and the base of the teeth. This makes it necessary to twist the wrist While brushing with an ordinary toothbrush. The corresponding hand movements are complex and are difficult to perform, particularly by children or people deprived of easy movement of the hand and/or arm.
In an effort to obtain more effective dental cleansing,
,various electrically powered toothbrushes have been designed for rotary as well as oscillatory brushing movements. Since the electric motor for such brushes must obviously be small to be accommodated in the brush handle, it has a correspondingly low output efficiency.
Furthermore, it is desirable to rinse the toothbrush during brushing to make the cleaning effective while, at the same time, holding Water consumption to a minimum for the entire operation which should take at least about 2 minutes for a thorough brushing to the teeth.
It is the primary object of this invention to provide an efficient rotary toothbrush meeting the requirements of modern dental hygiene while requiring a minimum supply of water for operating the brush and rinsing the teeth during brushing continuously.
The above and other objects are accomplished in accordance with the invention with a rotary toothbrush which comprises a hand held housing and an interchangeable brush. A miniature motor, such as a turbine operable by hydraulic pressure, is mounted in the housing and a rotary shaft is operably associated with the motor for rotation about the axis thereof, preferably by means of a planetary or like reduction gearing to reduce the relatively high velocity of the turbine to a lower rotary velocity of the shaft on which the brush is detachably mounted. The housing defines chamber means to which water is supplied under pressure through an inlet, flows through the housing chamber to operate the motor and rotor the shaft, and is drained through a water outlet. A water control including a valve is arranged on the housing for ready manipulation to control the water flow for blocking it from the mo tor, rotating the shaft in a first direction and reversing the rotational direction of the shaft. Channel means in the rotary shaft and the brush is in communication with the housing chamber for receiving rinsing water therefrom and conveying it to the brush whereby the same water supply is used for operating the motor and delivering rinsing water to the brush. The used water is sucked away by means causing a pressure reduction in the housing chamber between the motor and the water outlet to assist drainage of waste water from the motor.
The above and other objects, advantages and features of the present invention will become more apparent from the following detailed description of now preferred embodiments thereof, taken in conjunction with the accompanying drawing wherein FIG. l is a perspective view of a hand-held rotary toothbrush connected to the faucet of a wash basin;
FIG. 2 is an axial section of the toothbrush;
FIG. 3 is a transverse section along line lII-III of FIG. 2, showing a control device for reversing the rotary direction of the brush;
FIG. 4 is a transverse section, on an enlarged scale, along line lV-IV of FIG. 2, showing a planetary gearing for reducing the revolutions of the rotary brush;
FIG. 5 is an axial section, on an enlarged scale, showing a detail of the structure;
FIGS. 6 to 8 are enlarged sections illustrating different positions of the turbine wheel;
FIG. 9 is a perspective view of an alternative embodiment of the brush; and
FIG. 10 is a transverse section along line XX of FIG. 9, showing an arrangement for the detachable connection of the brush and protective shield.
Referring now to the drawing and first to FIG. 1, there is shown a rotary toothbrush 1 powered by water pressure, a flexible tube 2 having one end connected to faucet 3 on wash basin 4 by means of connector 5 while the other tube end is connected to the toothbrush. As shown in the drawing, the toothbrush has a section shaped to be gripped firmly by hand 6 of a user so that the user may comfortably perform all brush movements. For the sake of clarity, toothbrush 1 has been shown on a larger scale than the wash basin and other attachments.
The longitudinal section of FIG. 2 illustrates the toothbrush structure. As shown, the toothbrush comprises hand gripping section 7 and brush means 8 partially surrounded by protective shield 9. The hand gripping section of the toothbrush consists essentially of housing part 12 and cover part 3 which together define and enclose a chamber housing the rotary drive mechanism and necessary water passages. The power drive is provided by turbine wheel 14 keyed to turbine shaft 16. The turbine shaft is journalled in bearing plate 17 and has an end 19 projecting into axial bore 28 at the inner end of rotary shaft 18 carrying the brush. The bearing plate is carefully machined to fit into the chamber defined by housing 12 and has skirts l9 and 21 to enable the bearing plate to be retained in the housing chamber by placing cover 13 over the open housing end and securing it thereto by tightening screws 20. As will be seen in FIG. 2, the rim of cover 13 presses against skirt 19 of the bearing plate and opposite bearing plate skirt 21 simultaneously presses against a flange of bushing 22, thus holding the bushing flange against a shoulder in the housing chamber and retaining the bushing firmly therein.
Hand gripping section 7 has a cylindrical portion projecting therefrom and housing planetary gearing 15 shown best in FIG. 4. The planetary gearing comprises three planetary wheels 23, 24, 25 equidistantly spaced about turbine shaft 16 and meshing with gearing portion 30 on the shaft as well as with gearing portion 31 on the inner surface of the cylindrical portion of the hand gripping section.
Rotary shaft 18 has an enlarged end section 27 forming a squirrel s cage with three openings 32 housing the planetary wheels, shaft end section 27 being housed in the cylindrical portion of hand gripping section 7 and carrying axles 26 whereon the planetary wheels are mounted.
Cylindrical portion 33 of rotary shaft 18 projects from its end section 27 and is journalled in axial bore 34 of the cylindrical portion of hand gripping section 7.
O-ring or an equivalent sealing means is arranged in an annular groove in bore 34. The end of cylindrical shaft portion 33 projecting beyond housing 12 carries a preferably coarse thread 36, followed by conical part 37. The thread on the cylindrical shaft portion may be replaced by a bayonet or similar joint for attaching the brush to the shaft. Axial bore 38 passes from bore 28 through shaft 18 for conveying rinsing water to brush means 8.
The brush means comprises a brush part 39 mounted on support 40 formed with conical axial recess 42 confirming to conical part 37 and thread 41 to mesh with thread 36 for attachment of the brush means to rotary shaft 18. Support 40 has axial bore 43 aligned with bore 38 and in communication with discharge ports 44 for passing rinsing water to the brush part. As shown, support 40 is knurled at 47 to enable it to be gripped firmly for threadedly connecting the support to the shaft. When the brush means is mounted on the rotary shaft, support 40 must be screwed so tightly on shaft 18 that the conical surfaces 37 and 42 form a tight seal. Therefore, shaft 18 must be held against rotation when brush means 8 is emplaced or removed. For this purpose, the following locking arrangement is provided for rotary shaft 18:
The outer, ring-shaped part of rotary shaft end section 27 carries sector-shaped projections 45 facing corresponding projections 46 on the end face of bushing 22. When shaft 16 is in its freely rotatable position, as shown in FIG. 2, there is an axial gap S between projections 45 and 46. The shaft is mounted in housing 12 for axial displacement by a distance S exceeding the length of gap S Simple manual pressure on support 40 will slide shaft 18 down in the direction of hand gripping section 7 until projections 45 and 46 engage and thus prevent the shaft from turning about its axis. Thus held against rotation, the shaft can now be joined tightly with support 40 of brush means 8 or the support may be removed therefrom. In use, shaft 18 will be axially moved upwardly again into the position shown in FIG. 2.
The turbine wheel structure and operation is best shown in FIGS. 6 to 8. Turbine wheel 14 has vanes 48 shaped to be operated by jets of water for rotation clockwise or counterclockwise. Valve 49 cooperates with the turbine wheel, three different operating positions being shown in FIGS. 6 to 8.
Adjustable valve 49 is mounted for turning in bushing 22 fixedly held in housing 12 in a manner previously described. As best shown in FIG. 3, the valve may be adjusted into different positions by control rod 50 which is mounted for sliding movement in housing 12, the axis of slidable rod 50 extending transversely to the axis of rotary shaft 16 and rod 50 being reciprocable in the direction of double-headed arrow P The valve has a cylindrical portion 52 journalled in bushing 52 and the cylindrical valve portion has a gear segment 53 meshing with rack 51 forming the central portion of control rod 50. When the control rod is manually moved, by simple thumb pressure on rod ends 54, 55, for instance, in the direction of arrow P the valve will be turned in relation to bearing plate 17 fixedly retained in housing 12. Two O-rings 55, 56 near respective rods ends 54, are mounted in circumferential grooves in rod 50. These O-rings serve the double function of providing a seal between the rod and housing 12 and also tend because of their inherent resilency to retain the rod in each adjusted axial position, as will be described in detail hereinafter. The three positions of the control rod are determined by the positions of three annular grooves 57, 58, 59 in housing 12in the path of the axial movement of control rod 50. As the rod is axially moved, the O-rings will enter a respective one of the annular grooves, as illustrated by groove 58 in FIG. 3, thus being resiliently retained in the respective position without being locked thereinto against further axial movement by a relatively light pressure of the thumb.
The three mentioned positions of rod 50 correspond to the three positions of valve 49 shown in FIGS. 6 to 8. The valve has at least one port 60 for alignment with oblique port 61 or 62 in bearing plate 17. In the first position shown in FIG. 6, valve port 60 is in communication with bearing plate port 61 to permit water under pressure to flow in the direction of arrowP against vanes 48 of turbine wheel 14. This will bring about a clockwise rotation of the wheel and rotary shaft 16 in the direction of arrow P In the centered position shown in FIG. 7, valve port 60 is out of communication with any bearing plate port and the turbine wheel will stand still. In the position shown in FIG. 8, valve port 60 is in communication with bearing plate port 62 to permit water under pressure to fiow in the direction of arrow P to turn the turbine wheel and rotary shaft 16 in the counterclockwise direction indicated by arrow P Thus, rotation of shaft 16 may be reversed or stopped by axial movement of control rod 50.
Valve 49 is biased against bearing plate 17 be means of spring washer 63 mounted between the end face of bushing 22 and the cylindrical portion 52 of the valve.
In order to control the amount of rinsing water passing through axial bores 38, 43, shaft end 29 carries conical valve port 64 forming a needle valve with the inner end of bore 38 whereinto it projects, the bore end con;
stituting a valve seat for valve part'64. As shown in FIG.
5, water under pressure is forced into annular space 65- surrounding valve part 64 through lateral bore in shaft end section 27 in the direction of arrow P Rotary shaft 16 is axially displaceably mounted'on cover 13, conical valve port 64 being biased into (2105- ing bore 38 by compression spring 67 which is mounted on stop pin 71 in axial bore 69 of set screw 70. The set screw is threaded into cover 13 coaxially with shaft 16 and ball 68 is interposed between end 72 of pin 71 and the end of shaft 16. The stop pin has a length selected to permit a little axial play S between ball 68 and pin end 72 when the set screw has been threaded into cover 13 sufficiently to enable spring 67 to press shaft 16 upwardly for moving valve part 64 into closing engagement with bore 38. When water under pressure flows through valve 49 in the direction of arrow P or P, (FIGS. 6 and 8), it will press turbine wheel 14 downwardly against the bias of spring 67, the wheel being keyed to shaft 16 for movement therewith, and thus level out axial play S thus moving valve part 64 out of engagement with bore 38 and opening the same to receive a flow of rinsing water through bore 66. Adjustment of set screw enables the amount, of rinsing water passing through bore 38 to be regulated.
Hydraulic pressure for turning turbine wheel 14 and shaft 16 is supplied from wash basin faucet 3-by tubing I 2 which consists of flexible inlet tube 1 1 surrounded by flexible outlet tube 10. One end of the tubing is detachably mounted on connector 5 and the other tubing end is detachably mounted on nipple 73 which is integral with housing 12 and comprises inlet 74 whereon inner tube 11 is mounted to receive water under pressure flowing in the direction of arrow P The nipple inlet widens into chamber 75 defined by a thickened portion of the wall of housing 12, which forms the nipple. Chamber 75 is in communication with annular chamber 77 through lateral port 76, valve 49 being housed in chamber 77 so that water under pressure may flow through inlet 74, chamber 75, port 76, chamber 77 and valve port 60 for turning turbine wheel 14. Annular chamber 77 is in communication with annular chamber 78 surrounding the cylindrical portion of valve 49 and an axial bore in the end face of bushing 12 of a diameter larger than that of shaft 16 places chamber 78 in communication with annular chamber 79 surrounding end section 27 of shaft 18, thus permitting water to flow through lateral bore 66 in the direction of arrow P (see FIG. 5), as previously described.
Except forturbine shaft 16, planetary wheel axles 26, spring 67 and ball 68, spring 63, and possibly the O rings, brush part 39 and tubing 2, all parts of the tooth brush are preferably made of a molded synthetic resin. For this reason and due to practical production requirements, ports will be formed in the thickened portion of the wall of housing 12 adjacent chamber 75, and these ports are sealed With plugs 81), 80a.
Cover 13 and bearing plate 17 define chamber 82 below and around turbine wheel 14 to receive the water flowing through valve 4-9 and operating the turbine wheel, chamber 82 being in communication with chamber 75 through channel 81 boxed in thickened wall portion of housing 12. Channel 81 leads to the outlet of nipple 73 to which outer tube is attached.
Protective shield 9 for brush part 39 has a ringshaped connector part 83 for frictional engagement with cylindrical upper section 84 of housing 12 so that the shield may be detachably mounted on the toothbrush. This mounting will be facilitated if part 83 is somewhat elastic so as to be held firmly on housing section 84. A snap fit would also be possible.
In the modified embodiment of FIG. 9, the brush part is not an elongated cylindrical member, as shown in FIG. 2, but consists of spiral brush 39' enhancing the cleansing effect of the brush upon rotation. Furthermore, brush protective shield 9 carries fork-shaped re tainer 85 (see FIG. 10) gripping annular groove 86 of brush support 40'. This makes it possible to turn the shield in respect of the brush part. In either embodiment, it will be simple to remove the shield and the brush means for ready replacement by another shield and brush means so that different persons may use the device.
The operation of the rotary toothbrush hereinabove described will partly be evident from the described structure and will be further detailed hereinbelow.
In use, one end of tubing 2 with connector 5 is so mounted on faucet 3 that inner tube 11 is in communi cation with the faucet, which may be turned on to permit water to flow through tube 1 1 under pressure, while outer tube 10 if open at that end to drain water from the operating toothbrush in the direction of arrow P (See FIG. 1). The faucet is set for a moderate flow of water which, as shown by arrow P in FIG. 2, enters through inlet 73 and fills all the chambers in the toothbrush housing, as indicated by the arrows in FIG. 2 which show the direction of water flow, some of the water under pressure simultaneously flowing over through channel 81 to depressurize chamber 82. If valve 49 is in its center position (see FIG. 7), turbine wheel 14lwill stand still, i.e., no rotary driving power is transmitted to the brush shaft and no water enters chamber 82 through the valve. However, the water pressure will axially move brush shaft 18 the distance S so that it will be unlocked if it had previously been locked for replacement of the brush means, as described hereinabove.
Upon manipulation of control rod 50, valve 49 will be moved into an operating position, as indicated in FIGS. 6 or 8, so that hydraulic pressure will begin to turn the turbine wheel, the operating water flowing out through chamber 82 and being sucked into tube 10 by the water passing through channel 81. If desired, the direction of rotation may be reversed during operation by manipulation of control rod 50 in the previously described manner.
The rotary direction of the brush may be rapidly changed for every group of teeth being brushed so that brushing is effected in a direction from the gum upward towards the teeth so that food particles are not pressed down between the base of the teeth and the gums. During brushing, protective shield 9 prevents brush part 39 from coming into contact with parts of the mouth which should not be touched by the brush.
The amount of rinsing Water passing through discharge ports 44 to brush part 39 is set by screw in the manner previously described to any desired amount. Thus, the teeth are effectively brushed and simultaneously rinsed, the rotary control during operation being exceedingly simple by pressure manipulation of rod 50.
Most parts of the toothbrush being of molded plastic, mass production at low cost is available, a preferred synthetic resin for the manufacture of these molded parts being Teflon.
As shown in FIG. 2, it will be useful to place a floating anti-friction washer 87, for instance of Teflon or another suitable material of low friction coefficient, between section 27 of shaft 18 :and cylindrical portion 84 of housing 12 so as to seal off the housing chambers filled with water during operation.
A useful material for the manufacture of turbine shaft 16, planetary wheels 23-25 and their axles 26, ball 68 and springs 67 and 63 is stainless steel.
Since all the moving parts are automatically lubricated by the flowing water, they will be subject to slight wear only and have a long operating life. Also, water consumption during operation is low since the amount of rinsing water supplied to the brush obviously must be relatively limited and the amounts of water producing the turbine wheel operating jets through bores 61, 62 are also quite limited.
While the rotary toothbrush has been described herein in connection with certain preferred embodiments thereof, it will be clearly understood that various modifications may occur to those skilled in the art, particularly after benefitting from the present teaching, without departing from the spirit and scope of this invention as defined in the appended claims.
What is claimed is:
1. A rotary toothbrush comprising a housing shaped to be hand gripped and an interchangeable brush means, a motor means operable by hydraulic pressure mounted in the housing, a rotary shaft means operably associated with the motor means for rotation about the axis of the shaft means, the shaft means projecting from the housing and the brush means being detachably mounted thereon, the housing defining chamber means, an inlet for water under pressure and a water outlet, whereby water supplied under pressure through the inlet and flowing through the housing chamber means operates the motor means and rotates the shaft means, water flow control means arranged to control the water flow for blocking it from the motor means, rotating the shaft means in a first direction and reversing the rotational direction, channel means in the rotary shaft means and the brush means in communication with the chamber means for receiving rinsing water therefrom and conveying it to the brush means, and means causing a pressure reduction in the housing chamber means between the motor means and the water outlet for assisting drainage of waste water from the motor means.
2. The rotary toothbrush of claim 1, wherein the hydraulic pressure operable motor means comprises a turbine wheel having a plurality of vanes and arranged for rotation in reversible direction, a shaft extending through the housing, the turbine wheel being keyed to the shaft for rotating the shaft in the direction of wheel rotation, and a gearing interconnecting the shaft to the shaft means whereon the brush means is detachably mounted.
3. The rotary toothbrush of claim 2, further comprising a bearing plate adjacent the turbine wheel, the bearing plate being fixedly mounted in the housing and having two diagonally opposite ports obliquely inclined in opposite directions towards the vanes of the turbine wheel, and the water flow control means comprising a valve means having at least one port and means for moving the valve port out of communication with the bearing plate ports and into selective communication with a respective one of the bearing plate ports for blocking the motor means and rotating the shaft means in the reversible directions.
4. The rotary toothbrush of claim 3, wherein the water flow control means further comprises a control rod slidably mounted in a transverse bore in the housing, the rod having opposite ends projecting from the housing, and transmission means interconnecting the control rod to the valve means for moving the valve port in response to sliding of the control rod in the bore.
5. The rotary toothbrush of claim 4, further comprising snap means associated with the rod and the bore for resiliently retaining the rod in a selected one of three positions.
6. The rotary toothbrush of claim 3, further comprising spring means pressing the valve means against the bearing plate. 7
7. The rotary toothbrush of cliam 2, wherein the gearing comprises a planetary gear having three planetary gear wheels rotatably mounted in a section of the shaft means, a gearing portion on the turbine shaft and a gearing portion on the interior wall of the housing, the planetary gear wheels meshing with the gearing portions whereby rotation of the turbine shaft is transmitted to the shaft means for rotation thereof.
8. The rotary toothbrush of claim 7, wherein the turbine shaft is axially displaceably journalled in coaxial bores in the bearing plate and the shaft means section, the turbine shaft having an end projecting from the shaft means section into the channel means in the rotary shaft means, and the turbine shaft end carries a conical valve part whereby axial displacement of the turbine shaft opens and closes the channel means for flow of rinsing water to the brush means and shutting off the rinsing water flow.
9. The rotary toothbrush of claim 8, further comprising means for controlling the axial displacement of the turbine shaft, the displacement control means including a set screw threadedly mounted in the housing coaxially with the turbine shaft, a stop pin on the screw, a compression spring around the stop pin and a ball held between the compression spring and the opposite end of the turbine shaft, the stop pin and ball being coaxial with the turbine shaft, axial play being permitted between the ball and the opposite turbine shaft end.
10. The rotary toothbrush of claim 8, further comprising a bushing fixedly mounted in the housing between the shaft means section and the turbine wheel, the bushing having an end face defining a bore through which the turbine shaft extends, the bore having a diameter greater than the diameter of the turbine shaft, the rotary shaft means being axially displaceably journaled in the housing, and axially spaced projections on the shaft means section and the bushing end face for locking engagement upon axial movement of the shaft means in one direction whereby rotation of the shaft means is prevented and disengagement upon axial movement of the shaft means in the opposite direction whereby the shaft means is free to rotate.
11. The rotary toothbrush of claim 7, further comprising a floating anti-friction washer mounted between the shaft means section and the housing.
12 The rotary toothbrush of claim 1, further comprising a support for the brush means, the shaft means having a conical end and the support having a conforming conical recess to receive the support on the shaft means end, and means for detachably holding the support on the shaft means end.
13. The rotary toothbrush of claim 12, further com prising a protective shield for the brush means, the protective shield being detachably mounted on the housing, and a fork-shaped clamping means connecting the shield to the support for free rotation of the shield in respect of, and removal from, the support.
14. The rotary toothbrush of claim 1, further comprising a water supply and removal tubing attached to the housing inlet and outlet, the mbing including an inner tube connected to the inlet for supplying water under pressure to the housing chamber means, the chamber means including a first chamber adjacent the inlet, a second chamber wherein the motor means is arranged, a port connecting the first and second chambers, and a third chamber wherein the rotary shaft means is arranged, the second and third chambers being in communication, the channel means comprising a lateral bore in the rotary shaft means in communication with the third chamber for receiving rinsing water from the third chamber, and the tubing including an outer tube connected to the outlet for removal of waste water. I
15. the rotary toothbrush of claim 14, wherein the means causing the pressure reduction comprises a channel connecting the first chamber to the water outlet.