AU618528B2 - Toothbrush with means for indicating applied force - Google Patents

Abstract

While brushing the teeth with known toothbrushes, whether manually or mechanically operated, the user can involuntarily apply too much pressure, which may cause damage with far-reaching consequences to the gums, teeth and dental fixing devices. Such damage may be avoided by using a toothbrush which enables the user to achieve optimum pressure for brushing the teeth by simple means, and without using additional electrical or electronic aid. The head (3) of the toothbrush is so disposed on the shaft (1) of the toothbrush, that it flexes when a certain level of pressure is reached, enabling optimum pressure to be maintained while the teeth are brushed. An acoustic and/or tangible sign may be given when optimum pressure on the shaft (1) of the toothbrush is reached, or the shaft (1) may be formed at certain points like a leaf spring, in such a way that the flexible design of the toothbrush head ensures that an optimum or maximum pressure while brushing the teeth is not exceeded.

Description

AU-Al -13665/88 WELTORGANISATION FOR GEISTIGES EIGENTUM Pcr Internationales Btbro INTERNATIONALE ANMELDUNG VEROFFENTLIGHT NACH DEM VERTRAG OBER DIE (51) Internationale Patentklassifikation 4 )Anter tio aVe f tthuga me:W 88061 (21) Internationales Aktenzeichen: PCT/EP88/00137 (81) Bestimmungsstaaten: AU, JP, KR, NO, US.

(22) Internationales Anmieldedatumi: Februar 1988 (25.02.88) Verotfentlicht Mit internationalem Recherchenbericht.

Vor Ablauf der far Anderungen der Anspriiche zugelas- (31) Priori titsaktenzeichen: P 37 06345.6 senen Frist. Vertdffentlichung wird wiederhohl falls Anderungen eintreffen.

(32) Priorititsdatum: 27. Februar 1987 (27.02.87) (33) Prioritaitsland: DE, 'PinA. 7 (71) Anmelder (fa~r alle Bestimmungssmaten ausser US): BLENDAX-WERKE R. SCHNEIDER GMBH CO. EDE/DE]; Rheinallee 88, D-6500 Mainz 1 AUSTRAUIAN (72) Erfinder;und 1, Erfinder/Anmelder (nurfiir US) MIERAU, Hans-Die- F 26 SEP M98 ter [DE/DE]; Friedri ch-Ebert- Ring 37, D-8700 Wijrz-OIC burg TEGTMEIER, Ingeborg [DE/DE]; Alpen-PAETOFC ring 31, D-8011 Brunnthal (DE).

(74) Gemneinsamer Vertreter: BLE NDAX-WERKE R.

SCHNEIDER GMBH CO.; Rheinalt 88, D-6500 Mainz I (DE).

(4Ttle: TOOTHBRUSH

ZAHNBCJRSTE

3 t~ I (57) Abstract While brushing the teeth with known toothbrushes, whether manually or mechanically operated, the user can involuntarily apply too much pressure, which may cause damage with far-reaching consequences to the gums, teeth and dental fixing devices. Such damage may be avoided by using a toothbrush which enables the user to achieve optimum pressure for brushing the teeth by simple means, and without using additional electrical or electronic aid. The head of the toothbrush is so disposed on the shaft of the toothbrush, that it flexes when a certain level of pressure is reached, enabling optimum pressure to be maintained while the teeth are brushed. An acoustic and/or tangible sign may be given when optimnum pressure on the shaft of the toothbrush is reached, or the shaft may be formed at certain points like a leaf spring, in such a way that the flexible design of the toothbrush head ensures that an optimum or maximum pressure while brushing the teeth is not exceeded.

(57) Zusammenfassung Beim Putzen der Zdhne mit herkbmmlichen Zahnbiirsten f~ir manuelle oder mechanische Bettigung kann von dem Benutzer ungewollt emn zu hohier Anpre1~druck erzeugt werden, was zu folgereichen Beschadigungen des Zahnfleisches, der Ziihne und des Zahnhalteapparates filhren kann. Zur Vermeidung solcher Schdden ist eine Zahnbtirste geschaffen worden, mit der es dem Benutzer ermoglicht wird, den fMr das Zahneputzen optimalen Anpre~druck in einfacher Weise ohne zusfitzliche elektrische oder elektronische Hilfsmittel zu erzielen, was dadurch erreicht wird, daR der Barstenikopf der Zahnbtlrste am Bfirstenschaft bei Erreichen eines bestimmiten AnpreI~druckes derart auslenkbar angeordnet ist, dag emn optimaler Anpre~druck wdhrend des Zahneputzens einzuhalten ist. Hierf~ir kann entweder eine akustische und/oder fihlbare Anzeige bei Erreichung des optimalen AnpreF~druckes am Biirstenschaft vorgesehen sein, oder der Btirstenschaft kann stellenweise dlhnlich einer Blattfeder derart ausgeformt sein, daB beim Zdhneputzen bis zur Auslenkung des Mirstenkopfes emn optimaler oder maximaler Anprel~druck nicht 0berschritten werden kann.

11 The present invention relates to a toothbrush for manual or mechanical operation.

Optimal oral hygiene signifies the removal of existing deposits (microbial plaque) from the teeth and of food residues, as well as the prevention of these pathogenic deposits. A welcome increase in the consciousness of oral hygiene is in contrast to well-intentioned, increasingly-used but primarily intensive forceful brushing procedures which lead to alarming damage on both an acute and chronic scale by brushing traumata freelyexposed necks of teeth (gingival recession), puncture wounds in the gums due to toothbrush bristles (acute brushing lesions), splitting of the gums (Stillman splits), wedge-shaped losses of material in the root region close to the coronal region (wedgeshaped damage), under which conditions, because of the common present-day practice of increased consumption of acid foods and drinks, with the subsequent brushing procedures, the losses of tooth substance (erosion) can be substantially increased. The principle of action of these pathological phenomena is based upon the transmission, during the brushing procedure, of excessive force through the gums (gingiva) to the bone which holds the teeth (alveolar margins), and which is then resorbed. After the loss of this bony support from the roots of the teeth, the gums atrophy and the necks of the teeth become exposed. With the use of costly, computer-supported, investigations it has been undeniably established that increased force transmission is the main etiological factor of these acute and chronic brushing traumata which have been described.

An electric toothbrush is already known from the German Patent DE-PS 34 14 623 with which the user can exert a controlled pressure by means of an integrated electronic device. However it is not possible to use it without a supply of electrical energy and the device cannot be fitted to existing equipment.

The object of the present invention is therefore to provide a toothbrush which makes it possible for the user to apply the optimal pressure, when cleaning the teeth, in a simple manner without the need for additional electrical or electionic devices.

This object is achieved in accordance with the present 2 invention by the use of the characteristics referred to in Patent Claims whereas additional especially advantageous developments are featured in Patent Claims 2 to 4.

Because of the fact that the handle of the toothbrush is designed with a special profiled cross-section at a suitable location, there is a preferably-sudden mechanical deflection of the head of the toothbrush when a certain specified pressure is reached, thus providing the requisite conditions, in an especially simple and effectual manner, under which the brushing pressure applied by the user (patient) can rise to only a predetermined highest limit. When this highest limit is reached, the formerly curved deflection profile of the brush handle suddenly straightens out into a stretched position with altered flexibility, in which situation the characteristics of this alteration to the stiffness can be varied within wide limits by changing the curvature, the properties of the material and the thickness of the material forming the deflection profile. With the use of a thin, strongly-curved, profiled cross-section, it is possible to achieve high applied forces right utp to the yield limit, with subsequent greatly-reduced transmission possibilities.

However, as opposed to this, if the deflection profile of the brush handle is designed to have only a slight curvature, but with a greater cross-section, the effect described is lessened to the extent that, by variation of the curvature, of the profiled cross-section and/or of the material used, it is possible to achieve any desired characteristic curve for transmission of the brushing force. It is also possible, by the coupling together of two or more different deflection profiles, to achieve a characteristic transmission curve with various stages in order, for example, to achieve two "click points" at different pressures.

This makes it possible to get an indication of a too-low or a too-high application pressure over any desired band-width.

Wide distribution of toothbrushes with this trail-blazing innovation is to be desired amongst patients, especially young adults, because epidemiological investigations have shown that there is a representative number of 18- to 22-year-old persons 3 to whom the opportunity of having healthy teeth provides the incentive for vigorous brushing of the teeth which, when compared with results for persons of similar age groups in previous decades, leads to significantly greater occurrence of damage.

These innovative toothbrushes therefore serve a biologicallyorientated and, therewith, a successful program for dental health, eliminating the need for expensive operations to overcome exposure of the necks of the teeth, which are of doubtful success in the long term, and thus contributing to reduction of the costs of dental care.

Preferred examples of embodiment of the present invention are depicted diagrammatically in the-drawings, in which Fig. 1 is a hand-held toothbrush, Fig. 2 is a plug-in tooth brush for a preferably electromechanical operating device, Fig. 3 to 5 are various profiled cross-sections of the brush handle along the lines III III in Fig. 1 and Fig. 2, Fig. 6 to 8 are variations of the embodiments shown in Fig. 1 and 2 and which are also suitable for plug-in brushes with two successive "click points", where Fig. 6 depicts the initial setting of the toothbrush, Fig. 7 shows the intermediate setting of the toothbrush and Fig. 8 shows the third and final setting of the toothbrush.

In the case of the two examples of embodiment of a hand-held toothbrush and a plug-in toothbrush for use with an electromechanical device shown in Fig. 1 and Fig. 2 respectively,'the handle 1 of the toothbrush is designed in such a manner, in accordance with the clicking-frog principle, that there is a deflection region 2 adjacent to the head 3 of the toothbrush 4 which is similar to a leaf spring over portion of its length so that it is not possible to exceed a maximum or optimum applied pressure when brushing the teeth because of deflection of the head of the toothbrush when this pressure is reached. The head 3 of the toothbrush is arranged on the handle 1 in such a manner that when a predetermined pressure is reached the head is deflected suddenly so that it is possible to maintain an optimum applied pressure when brushing the teeth. Because of the mechanical deflection and the click which is heard when the maximum pressure is reached in the deflection region 2 of the toothbrush handle designed on the clicking-frog principle, a tangible and/or audible signal is emitted when the optimum applied pressure is reached or exceeded on the toothbrush handle.

Cross-sections of suitable deflection profiles 4 on the toothbrush handle 1 are depicted in Fig. 3 to Fig. 5 and these correspond to the sectional lines III III in Fig. 1 and Fig. 2.

Thus, a circular-arc deflection profile 4 transverse to its longitudinal direction is shown in Fig. 3 in the transition region between the toothbrush head 3 and the handle 1.

In the example of embodiment shown in Fig. 4, there are two profile strips 4a and 4b running in the longitudinal direction of the toothbrush handle 1 arranged in approximately the same way as the curved profile 4 in Fig. 3 at an obtuse angle to each other transversely to the longitudinal direction and separated from each other by a central longitudinal slot 4c so that when the maximum applied pressure is exceeded the strips become aligned with each other transversely to the longitudinal direction of the toothbrush handle 1 and the head 3 of the toothbrush is deflected from its original straight extended position into the deflected or clicked position 5 indicated by the dot-dash lines in Fig. 1 and Fig. 2 which is at an acute angle to the toothbrush handle 1 and the head 3 is in a substantially labile situation and brushing the teeth cannot be continued.

The third example of embodiment shown in Fig. 5 for the deflection profile 4 between the handle 1 and the head 3 of the toothbrush has a wavy cross-section transversely to the longitudinal direction of the toothbrush handle 1, but it functions n~' in practically the same manner as that described in relation to the other two examples shown in Fig. 3 and Fig. 4. In all three depicted examples of embodiment, the thickness of the material and the curvature or angular disposition of the strips 4a and 4b of the deflection profile 4 play an important role in the determination of the optimum or maximum applied pressure but, depending upon the particular requirements, these can be selected and shaped as desired. The toothbrush handle 1, the toothbrush head 3 and the deflection region 2 can be fabricated as a single unit from a suitable synthetic plastics material or composite material with appropriate elasticity and springiness.

In the case of the modified examples of embodiment shown in Fig. 6 to Fig. 8, it is possible to connect together in series two different deflection profiles, corresponding to Fig. 3 and Fig. 4 or Fig. 5, so that the toothbrush head 3 is bent down at an acute angle in relation to the toothbrush handle 1 in the non-stressed original position shown in Fig. 6 and when an adequate optimum applied pressure is exerted, after overcoming the resistance at the first click point, the toothbrush head 3 assumes the intermediate straight extended position shown in Fig. 7. After exceeding this optimum applied pressure and overcoming the resistance at the second click point, the toothbrush head 3 will occupy the deflected third position shown in Fig. 8 where it is tilted up at an acute angle in relation to the toothbrush handle 1 similar to that indicated by dot-dash lines in the two examples of embodiment shown in Fig. 1 and Fig. 2 and the head 3 is in a substantially labile situation so that i brushing the teeth cannot be continued.

Claims (2)

1. 2. A toothbrush for manual or mechanical operation, comprised of a handle which has more than one special profiled cross-section in order that by combining two or more different deflection profiles on the handle of the o: brush, a stepped deflection of the head of the brush is o 4 provided such that successive deflections occur at different contact pressures.
2. 3. A toothbrush according to Claim 2, comprised of a handle which has special profiled cross-sections, which are deflectable and which provide a perceptible indication at the handle of the brush when contact pressure provided by the head of the brush on the teeth has fallen below or .exceeded the optimum contact pressure for toothbrushing. V 4. A toothbrush according to Claim 1 or 3, wherein the perceptible indication which is provided at the handle of the brush is an audible indication. DATED THIS 17th DAY OF October 1991 BLENDAX-WERKE R. SCHNEIDER GmbH By Its Patent Attorneys; GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia