Self-Regulating Adaptive Bristle Toothbrush Head with Fluid-Based Pressure Balancing

Abstract

An adaptive toothbrush head (2) includes a sealed fluid chamber (6) positioned beneath one or more movable bristle-supporting structures (5) carrying bristles (3). Application of brushing force to a first region of the bristles (3) causes inward movement of a corresponding bristle-supporting structure (5) and displacement of a fluid (4) within the sealed chamber (6). The displaced fluid (4) redistributes pressure within the chamber (6) and exerts an outward force on at least one adjacent bristle-supporting structure (5), thereby promoting more uniform bristle contact across the toothbrush head (2). The pressure-balancing mechanism operates passively without electronic sensors or active mechanical actuators. The fluid (4) may comprise a liquid, a viscoelastic gel, a compressible gas, or air. The bristle-supporting structures (5) may comprise independent platforms or a single flexible membrane (13). The toothbrush head (2) may be coupled to either a manual or powered toothbrush handle (1) for oral cleaning.

Description

2. CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 63/773,381, filed Mar. 17, 2025, the entire contents of which are incorporated herein by reference.

3. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

4. BACKGROUND

4.1 Field

The present invention relates to toothbrush heads designed for enhanced oral hygiene by incorporating an adaptive bristle system with a fluid displacement pressure-balancing mechanism. This allows the bristles to dynamically conform to the user's teeth and gums, promoting even pressure distribution and enhanced cleaning efficiency.

4.2 Related Art/Problem

Traditional toothbrushes feature static bristles that do not conform to the unique contours of an Individual's teeth and gums. As a result, they do not provide optimal contact with the surface of the teeth, and often apply uneven pressure, leading to inefficient cleaning and potential discomfort, especially for users with sensitive gums, misaligned teeth, or orthodontic appliances. Some existing toothbrush designs attempt to offer adaptive bristles by using flexible materials, angled bristles, or mechanical adjustments. However, these approaches provide limited adaptation, as they lack a true self-regulating mechanism. In many cases, such designs still exert excessive force on certain areas while failing to make full contact with others, leading to inconsistent cleaning and potential gum irritation. The level of adaptation in these toothbrushes remain minimal and inefficient, do not adequately address the core problem of pressure imbalance. To overcome these limitations, the present invention introduces a toothbrush with adaptive bristles with a fluid displacement system. This pressure-balancing mechanism dynamically conforms to tooth contours, ensuring even force distribution across all bristles. This design approach offers a passive, yet highly responsive adaptation system, significantly improving both cleaning efficiency and user comfort.

5. BRIEF SUMMARY OF THE INVENTION

The present invention relates to a toothbrush head with an adaptive bristle system designed to dynamically conform to the contours of a user's teeth and gums through a fluid-displacement mechanism. Unlike conventional toothbrushes with static bristles, this design enables real-time bristle adjustment, ensuring consistent surface contact and even pressure distribution for improved brushing efficiency and user comfort.

The toothbrush head incorporates a sealed fluid chamber beneath the bristle assembly, designed to balance pressure and assist in bristle movement. When force is applied during brushing, the fluid shifts within the chamber, allowing bristles in high-pressure areas to retract while pushing bristles in low pressure areas outward. This passive self-regulating system provides even force distribution, preventing excessive pressure while maintaining effective cleaning contact.

This system functions without requiring electronic sensors or mechanical actuators, providing a passive, self-regulating solution that allows for even force distribution across the teeth and gums. The toothbrush maintains a familiar form factor, making it intuitive for users while delivering dynamic bristle adaptation for a more consistent brushing experience.

In various embodiments, the bristles are supported by multiple independent movable platforms or by a single flexible membrane forming at least a portion of the sealed fluid chamber. The fluid contained within the sealed chamber may comprise a liquid, a viscoelastic gel, a compressible gas, or air.

6. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side view of an exemplary toothbrush head including a housing and a plurality of bristles positioned above a sealed fluid chamber.

FIG. 1B is a perspective view of the toothbrush head of FIG. 1A.

FIG. 2A is a cross-sectional side view of the toothbrush head of FIG. 1A illustrating the sealed fluid chamber disposed within the housing and bristle-supporting structures positioned above the chamber.

FIG. 2B is a perspective cross-sectional view of the toothbrush head of FIG. 2A.

FIG. 3 is an enlarged cross-sectional detail view of a portion of the toothbrush head illustrating bristle-supporting structures positioned above the sealed fluid chamber.

FIG. 4 is a side cross-sectional flyout view of the toothbrush head illustrating an embodiment in which a bristle tuft is coupled to a translating sleeve received within an aperture of a carrier plate, with internal components separated for clarity.

FIG. 5 is an isometric cross-sectional flyout view of the embodiment of FIG. 4 illustrating internal components of the toothbrush head, including the translating sleeve, bristle-supporting structures, and the sealed fluid chamber.

FIG. 6 is a schematic cross-sectional view illustrating operation of the toothbrush head in which inward movement of central bristle-supporting structures displaces fluid within the sealed fluid chamber and urges bristle-supporting structures near opposite ends of the toothbrush head outward.

FIG. 7 is a schematic cross-sectional view illustrating operation of the toothbrush head in which inward movement of bristle-supporting structures near opposite ends of the toothbrush head displaces fluid within the sealed fluid chamber and urges central bristle-supporting structures outward.

FIG. 8 is a schematic view of an alternative embodiment in which bristles are supported on a single flexible membrane forming at least a portion of a boundary of the sealed fluid chamber.

7. DETAILED DESCRIPTION OF THE INVENTION

7.1 Definitions

As used herein, the term “fluid” includes liquids, viscoelastic gels, gases, and air, whether compressible or incompressible.

The term “sealed” refers to a configuration that substantially prevents leakage of the fluid during normal use and may include permanent or replaceable sealing structures.

The term “bristle-supporting structure” refers to any platform, carrier, membrane, or support element configured to carry one or more bristles and to move inward or outward relative to the toothbrush head.

The term “sleeve” refers to a tubular, collar, or carrier element coupled to a bristle tuft and configured to translate inward and outward relative to a surrounding structure (e.g., a carrier plate or housing) to permit bristle movement during use.

7.2 Overview of the Toothbrush Head Architecture

The toothbrush head (2) includes a housing, a sealed fluid chamber (6) disposed within the housing, a fluid (4) contained within the chamber, and one or more movable bristle-supporting structures (5) carrying bristles (3). During brushing, inward movement of a first bristle-supporting structure displaces fluid within the chamber and redistributes pressure so as to urge one or more other bristle-supporting structures outward, thereby promoting more uniform bristle contact. Additional component details and corresponding reference numerals are described in Section 7.3.

7.3 Component-by-component Description (with Reference Numerals)

Structure of the Toothbrush Head The toothbrush head (2) is designed to function similarly to traditional toothbrush heads in terms of size, shape, and user operation, making it intuitive for consumers. However, it integrates a self-adjusting bristle system (3,5) that dynamically conforms to the user's teeth, ensuring improved cleaning efficiency and comfort. The toothbrush head comprises the following key components:

1. Bristle Assembly (3, 5)

• • The bristles (3) are secured to a number of resilient bristle-supporting structures (5), each structure enabling groups of bristles to retract inward and extend outward in response to applied pressure.
  • This movement, in conjunction with the fluid-displacement system (4, 6), enables the bristles to dynamically adapt to the contours of a user's teeth, ensuring consistent surface contact for optimized cleaning efficiency.

2. Fluid Displacement System (4, 6, 14)

• • A sealed fluid chamber (6) containing fluid (4) is positioned beneath the bristle-supporting structures (5) and may include one or more internal partitions or flow guides (14). When force is applied to one region, the corresponding bristle-supporting structure moves inward toward the chamber and compresses the fluid in that region, causing displacement. The displaced fluid shifts to lower-pressure regions and creates an upward force that counterbalances the applied load, as illustrated in FIGS. 6 and 7. This self-adjusting mechanism helps prevent localized pressure buildup and maintain consistent structural support.

In some embodiments, the sealed fluid chamber is completely filled with the fluid, while in other embodiments the chamber is partially filled to adjust pressure response characteristics. The viscosity, elasticity, or compressibility of the fluid may be selected to modify resistance to inward movement of the bristle-supporting structures and to influence recovery behavior.

3. Enclosure & Sealing Components

The toothbrush head enclosure (FIGS. 1A-1B and 2A-2B) is sealed to prevent leakage and ensure the integrity of the fluid system. The fluid chamber (6) may be completely filled or partially filled to provide effective displacement and controlled pressure distribution in response to applied force.

Sealing of the housing may be achieved by overmolding, adhesive bonding, welding, or equivalent techniques sufficient to prevent fluid leakage during repeated brushing cycles.

7.4 Operation/Mechanism (How Pressure Balancing Happens)

Mechanism of Bristle Adaptation. The toothbrush head shown in FIGS. 1A-1B and 2A-2B functions similarly to a conventional toothbrush but introduces dynamic bristle adaptation through fluid displacement within the sealed chamber. As a user brushes, some bristles are pressed inward against the tooth surface by an applied downward force (7), and the associated bristle-supporting structures move inward toward the chamber, displacing the underlying fluid.

This fluid displacement (8) causes the fluid to shift to lower-pressure regions, generating an upward or outward force (11) that urges other bristle-supporting structures outward where less or no pressure is applied.

In preferred embodiments, the sealed fluid chamber forms a single continuous pressure-balancing chamber extending beneath multiple bristle-supporting structures. This passive hydraulic coupling allows the bristles to dynamically conform to tooth contours while maintaining more uniform contact and force distribution across the toothbrush head.

FIG. 6 illustrates a condition in which pressure is applied to central bristles, causing the associated bristle-supporting structures to move inward toward the fluid chamber. This inward movement displaces fluid within the chamber, generating an outward force that urges bristle-supporting structures near the ends of the toothbrush head outward.

• • FIG. 7 illustrates an alternative condition in which pressure is applied to bristle-supporting structures near the ends of the toothbrush head. In this case, inward movement of the end structures displaces the fluid and generates an upward force that urges the central bristle-supporting structures outward.
  • Familiar Form & Use: Resembles a standard toothbrush and is intended to promote ease of adoption.
  • Adaptive Bristles: Adjust dynamically to tooth contours for enhanced cleaning.
  • Self-Adjusting Bristle System: Bristle movement and pressure regulation are enabled primarily by fluid displacement, with or without supplemental mechanical elements to optimize adaptation.
  • Fluid-Based Pressure Balancing: Reduces excessive pressure on sensitive areas while maintaining consistent cleaning force.
  • Versatile Implementation: Compatible with manual and electric toothbrush designs while maintaining adaptive properties across different brushing styles.

This toothbrush head design introduces self-regulating bristle movement through fluid displacement while maintaining the familiar feel and usability of a conventional toothbrush.

7.6 Alternative Embodiments

The present invention may be implemented in a variety of embodiments to optimize performance, manufacturability, and user experience while maintaining the fluid-displacement pressure-balancing mechanism described herein.

Chamber type (integrated cavity vs. encapsulated reservoir). In some embodiments, the sealed fluid chamber is an integrated cavity formed within the toothbrush head housing. In other embodiments, the fluid is contained within a separate sealed deformable reservoir (bladder or bag) positioned within the housing. The encapsulated reservoir may be replaceable and may reduce leakage risk by containing the fluid within a pre-tested component.

Bristle support type (multiple platforms vs. single membrane). In some embodiments, independent bristle groups are mounted on separate movable platform regions that are guided for controlled inward and outward movement relative to the housing. In other embodiments, the bristles are mounted to a single continuous flexible membrane (13) that forms at least a portion of a boundary of the sealed fluid chamber, providing a softer and more continuous conformity response (see FIG. 8).

Platform sealing architectures for a single continuous chamber. For embodiments employing multiple platform regions over a single continuous chamber, the platforms may be sealed while remaining fluid-coupled in several ways, including: (i) stiff islands bonded to a continuous flexible diaphragm that forms the chamber boundary; (ii) a continuous cover sheet with localized bellows regions that flex with platform movement while maintaining a perimeter seal; and (iii) an internal sealed reservoir (bladder) that defines the fluid boundary, where platform feet compress the reservoir locally without direct fluid contact.

Bristle anchoring and movable tuft carriers. In some embodiments, the bristles are installed through openings in a flexible membrane or through openings in a rigid carrier plate or platform region and secured by any suitable tufting or anchoring technique. In some embodiments, one or more bristle tufts are coupled to respective sleeves received in corresponding apertures of a carrier plate (9), as illustrated in FIGS. 4 and 5. The sleeves may be configured for low-friction inward and outward translation relative to the housing or carrier plate, such that the sleeves function as the bristle-supporting structures or as subcomponents thereof. Inward movement of a sleeve may locally compress a boundary portion of the sealed fluid chamber or a deformable reservoir contained within the housing, thereby displacing the fluid and contributing to the pressure-balancing behavior described herein.

Fluid medium (liquid vs. gel vs. gas/air). The fluid may comprise a non-toxic liquid (e.g., water or silicone oil), a viscoelastic gel providing controlled resistance, or a compressible gas or air. The fluid properties may be selected to tune resistance to inward movement and recovery behavior.

Fill state and tuning. In some embodiments, the sealed chamber is completely filled with the fluid. In other embodiments, the chamber is partially filled to provide a controlled compressible volume. One or more baffles, partitions, or flow restrictors may be provided to guide fluid displacement and to tune cross-coupling between regions and response time.

Manual vs. powered compatibility. The toothbrush head may be used with a manual toothbrush handle, relying on user-applied force to trigger bristle adaptation. In other embodiments, the head may be coupled to a powered handle, where oscillatory or vibratory motion may enhance fluid movement while the pressure-balancing mechanism remains passive.

Optional mechanical elements. While the pressure-balancing mechanism may operate without mechanical actuators, some embodiments may include auxiliary elements such as springs, elastic members, diaphragms, or valves to bias a return toward a neutral position or to regulate fluid flow rate.

Replaceable vs. permanent head. In some embodiments, the toothbrush head is a sealed unit intended for a service life and replacement. In other embodiments, the head or the encapsulated reservoir may be configured for replacement or refurbishment.

7.7 Manual/electric Compatibility

Manual Vs. Electric Toothbrush Compatibility

The toothbrush head can be implemented as part of a standard manual toothbrush handle (1), relying solely on user-applied force to trigger bristle adaptation.

In another embodiment, the toothbrush head is configured to be coupled to a powered toothbrush handle, where vibrations or oscillations enhance the fluid movement and bristle adaptation response.

7.8 Best Mode/Example Build

Example implementation (best mode). In one exemplary embodiment intended for manufacture as a manual toothbrush head, the toothbrush head includes a rigid polymer housing defining an interior cavity sized to receive a pre-sealed deformable fluid reservoir (bladder or bag). The reservoir defines a single continuous chamber extending laterally beneath a plurality of bristle-supporting structures. In the best mode, the reservoir is sized to fit tightly within the cavity (e.g., with minimal clearance or light interference fit) to reduce wrinkling and to promote repeatable displacement behavior. The reservoir may be contoured (e.g., with a shaped upper wall, localized lobes, or variable wall thickness) to provide a stronger outward bias in low-pressure regions when fluid is displaced from a high-pressure region during brushing.

Housing and bristle-supporting structures. The housing may be formed from polypropylene (PP) or ABS. In the best mode, an upper carrier plate (9) or frame defines an array of apertures. A plurality of sleeves is received in the apertures and are guided for limited inward and outward travel relative to the housing by ribs, posts, rails, or wall features formed in the housing and/or the carrier plate (9). Each sleeve carries one or more bristle tufts. The tufts may be secured to the sleeves by any suitable method, including staple-set tufting, adhesive fixation, thermal staking, in-mold anchoring, or other anchoring techniques. Each sleeve may include a rounded load-spreading foot configured to contact and locally compress the reservoir without sharp edges, and a flange or stop surface configured to cooperate with the carrier plate to limit travel.

As illustrated in FIGS. 4 and 5, the sleeve-supported bristle assemblies may be shown in cross-sectional and flyout views to illustrate the spatial relationship between the sleeves, the carrier plate (9), and the sealed fluid chamber disposed beneath the bristle-supporting structures.

Sealed reservoir. The reservoir (bladder or bag) may be formed from silicone elastomer, TPU, or another flexible polymer film and is sealed around its perimeter to contain the fluid. The reservoir may be pre-filled and sealed as a component prior to assembly into the housing, enabling component-level leak testing. In some embodiments, the reservoir includes alignment features (e.g., ribs, tabs, or a locating frame) to maintain registration between contoured regions of the reservoir and corresponding bristle-supporting structures. The fluid may be a non-toxic liquid such as silicone oil, water, or another biocompatible liquid; in some embodiments the reservoir is fully filled, while in other embodiments the reservoir is partially filled to provide a controlled compressible volume.

Assembly and sealing. During assembly, the reservoir is placed into the housing cavity, and the carrier plate and sleeves are installed above the reservoir. A cover frame or upper housing portion may be joined to the housing to capture the sleeves and maintain their guided movement within the carrier plate. In some embodiments, travel of each sleeve is limited by one or more stop structures such as ridges, flanges, or shoulders formed on the sleeve and cooperating with corresponding features of the carrier plate or housing.

The housing components may be joined by ultrasonic welding, laser welding, adhesive bonding, overmolding, or another technique sufficient to maintain structural integrity during repeated brushing cycles. In embodiments using a fill port for an integrated cavity (instead of a pre-sealed reservoir), the cavity may be filled through the port and then sealed by a plug, weld, or heat-stake feature.

Travel limits and response tuning. Sleeve travel may be limited by one or more mechanical stops to a stroke suitable for oral cleaning, for example about 1 mm to about 3 mm. In some embodiments, one or more baffles, partitions, cages, or flow restrictors are disposed within the single continuous chamber (or constrain the reservoir) to guide fluid displacement and to tune response time and cross-coupling between adjacent sleeves. In some embodiments, the contoured geometry or wall-thickness profile of the reservoir is selected to increase outward bias in one or more regions when fluid is displaced.

Operational Considerations. If the chamber is not adequately sealed, leakage of the fluid can reduce or eliminate the pressure-balancing effect and may prevent the bristle-supporting structures (e.g., sleeves or platform regions) from returning toward a neutral position. Accordingly, sealing structures and materials are selected to maintain integrity over repeated deformation cycles and exposure to water, toothpaste, and temperature variation encountered during normal brushing.

7.9 DRAWING REFERENCE NUMERALS

• • 1: Toothbrush Handle
  • 2: Toothbrush Head Casing
  • 3: Bristles
  • 4: Fluid
  • 5: Bristle-supporting structure or sleeve platform
  • 6: Sealed fluid chamber
  • 7: Down force by pressing into the teeth
  • 8: Fluid displacement in action
  • 9: The carrier plate
  • 11: Up force by fluid displacement
  • 13: Flexible one-piece membrane with bristles
  • 14: Channel partition for efficient fluid displacement

Claims

1. A toothbrush head, comprising:

a housing defining an interior region;

a sealed fluid chamber disposed within the housing, the sealed fluid chamber defining a single continuous interior volume that extends laterally beneath a plurality of bristle-supporting structures such that regions of the interior volume beneath the bristle-supporting structures are in fluid communication;

a fluid contained within the sealed fluid chamber; and

the plurality of bristle-supporting structures positioned above the sealed fluid chamber, each bristle-supporting structure carrying one or more bristles and being movable relative to the housing;

wherein each bristle-supporting structure is operatively coupled to a movable boundary portion of the sealed fluid chamber such that inward movement of a first bristle-supporting structure toward the sealed fluid chamber displaces the fluid within the single continuous interior volume, and the displaced fluid redistributes pressure within the chamber to exert an outward force on at least one second bristle-supporting structure, thereby passively coupling movement between the bristle-supporting structures.

2. The toothbrush head of claim 1, wherein the bristle-supporting structures comprise rigid platform regions bonded to a continuous flexible diaphragm forming at least a portion of a boundary of the sealed fluid chamber.

3. The toothbrush head of claim 1, wherein the bristle-supporting structures comprise respective bristle-supporting regions of a single continuous flexible membrane that forms at least a portion of a boundary of the sealed fluid chamber, and wherein the one or more bristles are attached to the flexible membrane at the bristle-supporting regions.

4. The toothbrush head of claim 1, wherein the sealed fluid chamber comprises an integrated cavity formed within the housing.

5. The toothbrush head of claim 1, wherein the sealed fluid chamber comprises a pre-sealed deformable reservoir positioned within the housing.

6. The toothbrush head of claim 5, wherein the bristle-supporting structures are configured to compress the deformable reservoir to displace the fluid within the deformable reservoir.

7. The toothbrush head of claim 1, wherein the fluid comprises a non-toxic liquid.

8. The toothbrush head of claim 7, wherein the non-toxic liquid comprises water or silicone oil.

9. The toothbrush head of claim 1, wherein the fluid comprises a viscoelastic gel configured to provide resistance to inward movement of the bristle-supporting structures.

10. The toothbrush head of claim 1, wherein the fluid comprises a compressible gas or air.

11. The toothbrush head of claim 1, wherein the fluid comprises a liquid, and the sealed fluid chamber is completely filled with the liquid to substantially eliminate a gas pocket.

12. The toothbrush head of claim 1, wherein the sealed fluid chamber is partially filled with the fluid to provide a controlled compressible volume.

13. The toothbrush head of claim 1, further comprising one or more internal flow-guide structures disposed within the sealed fluid chamber, the internal flow-guide structures defining subregions of the single continuous interior volume that remain in fluid communication, and configured to direct fluid displacement between the subregions in response to movement of the bristle-supporting structures.

14. The toothbrush head of claim 1, further comprising a flow restriction structure within the sealed fluid chamber configured to control a rate of pressure redistribution between adjacent regions.

15. The toothbrush head of claim 1, further comprising one or more travel limit structures configured to limit inward travel of each bristle-supporting structure to a predetermined stroke.

16. The toothbrush head of claim 1, wherein each bristle-supporting structure is resilient and configured to return toward a neutral position when external force is reduced.

17. The toothbrush head of claim 1, wherein the housing is sealed to prevent leakage of the fluid during repeated brushing cycles.

18. The toothbrush head of claim 1, wherein the toothbrush head is configured to be detachably coupled to a toothbrush handle.

19. The toothbrush head of claim 18, wherein the toothbrush handle is a manual toothbrush handle.

20. The toothbrush head of claim 18, wherein the toothbrush handle is a powered toothbrush handle configured to impart oscillatory or vibratory motion, and wherein the fluid-based pressure-balancing mechanism operates independently of the powered motion.

21. The toothbrush head of claim 1, wherein the sealed fluid chamber comprises a pre-sealed deformable reservoir sized to fit within the housing with minimal clearance or an interference fit to reduce wrinkling and to promote repeatable pressure redistribution.

22. The toothbrush head of claim 21, wherein the deformable reservoir is contoured or has a variable wall thickness profile configured to bias outward movement of at least one bristle-supporting structure when fluid is displaced from another region.

23. The toothbrush head of claim 1, wherein at least one bristle tuft is coupled to a sleeve received in a corresponding aperture and configured for inward and outward translation relative to the housing or a carrier plate.

24. The toothbrush head of claim 1, wherein the bristle-supporting structures are configured to be independently displaceable such that, during brushing, a first bristle-supporting structure can be displaced inward by contact with a tooth surface while an adjacent second bristle-supporting structure remains at a different displacement position relative to the housing.

25. The toothbrush head of claim 1, wherein the single continuous interior volume comprises a plurality of local chamber portions respectively positioned beneath corresponding bristle-supporting structures, and one or more fluid passages interconnecting the local chamber portions to maintain fluid communication among the local chamber portions.

26. The toothbrush head of claim 23, wherein inward movement of the sleeve locally compresses a deformable boundary portion of the sealed fluid chamber to displace the fluid.

27. The toothbrush head of claim 5, wherein the deformable reservoir includes a contoured wall geometry or variable wall-thickness profile configured to bias outward movement of one or more selected bristle-supporting structures when fluid is displaced from another region of the deformable reservoir.