electric toothbrush

Abstract

The present invention provides an electric toothbrush comprising a replacement head connectable to a handle via a coupling device. The handle has a drive mechanism, and the replacement head has a brush head and a motion transmitter functionally connected to the brush head for driving the brush head. The handle has a coupling rod terminating at a free end and comprising a coupling pin extending from the rod. The replacement head comprises a generally tubular portion formed by a replacement head wall defining an interior space for receiving the coupling rod of the handle. The coupling device comprises a pair of mutually opposed and elastically deformable cantilever arms disposed adjacent to the replacement head wall in the interior space of the replacement head. Each of the cantilever arms terminates in a coupling surface for engaging the coupling pin of the rod for a secure and detachable connection between the handle and the replacement head.

Description

Technical Field

[0001] The present disclosure relates to electric toothbrushes and, more particularly, to a coupling arrangement between a handle of a toothbrush and an attachment member or replacement head, wherein a replacement head having a functional brush head is connected to a toothbrush handle including a drive shaft for driving the brush head. Background Art

[0002] Electric toothbrushes typically have removable and replaceable attached brush heads, also known as "replacement heads," so that a common handle can be used by multiple family members, each with their own personal replacement head. Furthermore, when the brush head becomes worn and / or otherwise requires replacement, only the replacement head needs to be replaced—not the entire electric toothbrush including the handle.

[0003] During the toothbrush brushing process, various forces must be transmitted through the connection between the replacement head and the handle during the brushing operation. These forces specifically include cleaning forces, driving forces, axial forces, and radial forces acting on the replacement head and / or the handle. The connection between the replacement head and the handle is usually achieved in such a way that radial forces are absorbed or dissipated in the handle, while axial forces are absorbed or dissipated in the drive shaft. To achieve this, the tubular connector of the replacement head is usually pushed onto the connecting rod or neck of the toothbrush, and the drive shaft disposed in the brush tube of the replacement head is connected to the drive shaft protruding from the end of the connecting rod of the handle.

[0004] An example of such a system is described in EP 0500537 B1, according to which the handle neck and the tubular connecting piece are provided with cross sections that deviate from a circle in a correspondingly complementary manner, so that radial forces can be better absorbed. To achieve the transmission of axial forces, the drive shaft in the brush tube can be pushed onto the drive shaft on the handle and fixed there by a latching connection.

[0005] WO 00 / 76420 A1 proposes to achieve axial and rotational fixation at the handle neck. For these purposes, a serrated rubber flange is provided in the tubular connection to which the brush is attached. This flange can be pushed onto the handle neck, which deviates from a circular shape. Furthermore, a locking tongue is provided on the tubular connection, which can be pushed onto the outer circumferential surface of the handle neck and locked there; this is intended to provide additional fixation to prevent axial disengagement. However, the additional axial fixation achieved by this latching device is limited by the fact that the outer circumference of the handle neck may become dirty, for example with toothpaste residue. Furthermore, the neck of the toothbrush is sometimes gripped by fingers, which can lead to unintentional disengagement due to external pressure on the latching connection.

[0006] US Patent 6,836,917 proposes an electric toothbrush having an L-shaped groove on the neck of the toothbrush. A pin provided on a push-in connector for attaching the brush moves into the groove, allowing the attached brush to be secured by pushing it in and rotating it in a bayonet-type manner. Furthermore, a drive shaft engagement is provided. However, if these forces are applied in the correct (so to speak) rotational direction relative to the handle, radial forces can cause the bayonet connection to unintentionally disengage, thus requiring additional securing measures.

[0007] DE 10209320A1 discloses an electric toothbrush in which only the toothbrush head can be replaceably locked to the handle; i.e. the toothbrush head does not have a drive shaft for driving it. Instead, the drive shaft on the handle must be screwed into the toothbrush head, which can sometimes cause some problems and requires a specific drive movement of the drive shaft.

[0008] US Pat. No. 8,671,492 discloses an attachment component for an electric toothbrush, wherein a connector has at least one internal latching element that is arranged to move into the interior of a handle neck and form a detachable connection between the attachment component and the handle neck. The internal latching element is offset radially inwardly relative to the diameter of the internal cylindrical surface of the connector. A gap between the exterior of the internal latching element and the inner cylindrical surface allows the wall of the handle neck to move into the gap.

[0009] US2014 / 0130274A1 discloses a structure for coupling a replacement head to a toothbrush handle that ensures proper alignment and simplifies loading and unloading of the replacement head from the handle. In one embodiment, the replacement head includes a tubular sleeve forming a cavity and first and second upper cam surfaces forming shoulders within the cavity. The first and second upper cam surfaces are separated by first and second axial slots of different configurations, which prevent the replacement head from being loaded onto the handle of an oral care implement in an improper rotational orientation by interacting with first and second bosses on the handle.

[0010] US2014 / 0341636A1 (EP2913026A1) discloses a replacement head and an oral care implement incorporating the replacement head, wherein the replacement head can be separated from the handle of the handle by withdrawing the replacement head from the handle along the longitudinal axis of the oral care implement, which causes a locking member on the replacement head to disengage from an engagement rib on the handle. The locking member and the engagement rib can be aligned with or angled relative to the longitudinal axis of the oral care implement. A portion of the shaft can be visible through a portion of the replacement head to reinforce a proper connection between the replacement head and the handle.

[0011] Other references that disclose various techniques and methods for coupling a replacement head to a handle of an electric toothbrush include: US 4,017,934; DE 2527130 A1; DE 2633848 A1; US ​​6,952,855; US 3,400,417; and US 9,237,943.

[0012] The present disclosure provides further improved electric toothbrushes, improved replacement heads, improved handles; and improved handle-replacement head coupling mechanisms for such electric toothbrushes, wherein an easily operable coupling is formed between the replacement head and the handle, which holds the replacement head securely and with as little play as possible on the handle, while still enabling easy coupling (including engagement and disengagement) between the handle and the replacement head. Summary of the Invention

[0013] In one aspect, the present disclosure relates to an electric toothbrush having a longitudinal direction or axis and comprising a handle and a replacement head constructed and configured to be attached to the handle via a coupling device. The handle has a drive mechanism, and the replacement head has a brush head and a motion transmitter functionally connected to the brush head for driving the brush head. The handle also includes a coupling rod having an outer wall extending in a direction parallel to the longitudinal axis and terminating at a free end; and the coupling rod has a coupling pin extending therefrom in a direction non-parallel to the longitudinal axis. The replacement head has a generally tubular portion formed by a replacement head wall defining an interior space, the interior space being constructed and configured to receive the coupling rod of the handle therein when the replacement head is attached to the handle. The coupling device includes a pair of mutually opposing cantilevered arms disposed within the interior space of the replacement head and adjacent to the replacement head wall, each of the arms terminating in a coupling surface constructed and configured to engage the coupling pin for secure and releasable connection therewith.

[0014] In another aspect, the present disclosure relates to a replacement head for an electric toothbrush having a longitudinal axis. The replacement head, constructed and arranged to be attached to a handle of an electric toothbrush, has a removable brush head and includes a generally tubular structure formed by a replacement head wall defining an interior space, the interior space being constructed and arranged to receive a coupling rod of the handle therein. The replacement head includes a motion transmitter functionally connected to the brush head for driving the brush head. The replacement head includes a coupling arrangement comprising a pair of mutually opposed cantilevered arms disposed in the interior space of the replacement head and adjacent the replacement head wall, each of the arms terminating in a coupling surface constructed and arranged to engage a coupling pin extending from the coupling rod of the handle for secure and detachable connection therewith.

[0015] In yet another aspect, the present disclosure relates to a coupling mechanism for an electric toothbrush having a longitudinal axis and comprising a handle and a replaceable replacement head. The coupling mechanism includes a handle coupling portion and a replacement head coupling portion that are constructed and configured to engage with each other, thereby providing a secure connection between the handle and the replacement head. The handle coupling portion includes a coupling rod disposed at one end of the handle along the longitudinal axis and a pin protruding from the rod in a direction non-parallel to the longitudinal axis, the coupling rod having an outer wall terminating at its free end. The replacement head coupling portion includes a generally tubular structure having a replacement head wall and an interior space therebetween, the interior space being constructed and configured to receive the coupling rod of the handle coupling portion therein, and a pair of mutually opposing cantilevered arms disposed in the interior space, each of the arms terminating in a coupling surface that is constructed and configured to engage the coupling pin of the handle coupling portion for secure and detachable connection therewith.

[0016] In one embodiment, the coupling pin extends in a direction substantially perpendicular to the longitudinal axis and / or substantially perpendicular to the direction of the outer wall of the coupling rod. The coupling rod may advantageously include a rib oriented along the longitudinal axis and having a first (lower) end and a second (upper) end opposite to the first end. The rib may be arranged adjacent to the pin. In one embodiment, the pin is arranged between or in the middle of the first and second ends of the rib. The replacement head may include a groove constructed and configured to engage the upper end of the rib of the coupling rod to limit the axial movement of the replacement head relative to the handle when the replacement head is axially attached to the handle.

[0017] Each of the two mutually opposing cantilever arms terminates at a coupling surface. More specifically, the first cantilever terminates at a first coupling surface, and the second cantilever terminates at a second coupling surface. The first coupling surface is opposite to and faces the first coupling surface. The first and second coupling surfaces are constructed and configured to simultaneously surround the coupling pin at opposite sides of the coupling pin when the replacement head is attached to the handle. Each of the coupling surfaces includes a sliding portion and a clamping portion adjacent to the sliding portion. The distance between the mutually opposing sliding portions of the first and second coupling surfaces can be from about 0.4 mm to about 5 mm, from about 0.5 mm to about 4.5 mm, from about 0.6 mm to about 3 mm, and particularly from about 1 mm to about 2 mm. The diameter of the pin (or if the pin is not cylindrical, the equivalent size orthogonal to the sliding portion) can be from about 0.8 mm to about 6 mm, from about 1 mm to about 5 mm, and from about 2 mm to about 4 mm. The pins may have a cross-section of any suitable shape, including, for example, shapes including circular, oval, rectangular, trapezoidal, oblong, pentagonal, hexagonal, and any other suitable polygonal shape or any portion thereof.

[0018] When the replacement head is axially attached to the handle, i.e., when the replacement head is axially moved relative to the handle and the pin disposed thereon, the coupling surfaces are constructed and arranged to slidably and resiliently engage the coupling pin. During attachment, the mutually opposing sliding portions of the coupling surfaces slide downwardly into resilient contact with the pin. When the pin reaches the clamping portion, the pin is pulled into snap-fit ​​engagement with the coupling surfaces within the clamping portion. To facilitate entry of the pin into the space between the two coupling surfaces, each of the sliding portions may include a ramped surface.

[0019] The sliding portions of the first and second coupling surfaces can be arranged substantially parallel to the longitudinal axis (and therefore parallel to each other). Alternatively, at least one of the sliding portions can be angled relative to the longitudinal axis. The angle between the sliding portions can be from about 0.1 degrees to about 20 degrees, from about 1 degree to about 15 degrees, from about 1.5 degrees to about 10 degrees, and particularly from about 2 degrees to about 3 degrees. In one embodiment, each of the sliding portions is angled symmetrically relative to the longitudinal axis so that the space between the mutually opposing sliding surfaces increases upward (i.e., from the inclined surface to the clamping portion). When the pin slides along the sliding surface, due to the elasticity of the cantilever and the associated pressure of the coupling surface acting on the pin, such a configuration is conducive to pulling the pin into the clamping portion of the coupling surface.

[0020] When the replacement head is attached to the handle, the space or gap existing between the two mutually opposing coupling surfaces of the cantilever arm elastically expands as the pin slides along the opposing sliding portions of the coupling surfaces. When this occurs, the elastic (or resilient) deformation or movement of the cantilever arm can include radial bending elastic deformation, i.e., elastic movement of the arm away from the longitudinal axis of the toothbrush; axial bending elastic deformation, i.e., elastic movement of the arm along the longitudinal axis of the toothbrush; torsional-twisting elastic deformation, i.e., elastic torque movement of the cantilever arm, in which the coupling surface rotates relative to the portion of the arm adjacent to the "hinge" or "root" of the arm (from which the arm extends); and any combination thereof.

[0021] Because the replacement head is repeatedly attached and detached from the handle, especially in environments containing abrasive materials such as toothpaste slurry, wear is inevitable at the interface between the pin and the coupling surface. Therefore, it is advantageous to make the pin (which is part of the handle) from a material with a hard surface, such as steel, ceramic, reinforced plastic, or a hard surface coating material. The coupling surface (which is part of the replacement head) can be made of plastic. This arrangement advantageously meets the functional requirements of the handle and replacement head over their respective expected lifespans.

[0022] The pin can have any suitable shape, such as cylindrical or prismatic, but a cylindrical shape is preferred. Accordingly, the clamping portion of the coupling surface can also be shaped to have a circular or semicircular shape, wherein the diameter of the pin is substantially equal to the equivalent diameter of the clamping portion. In such an arrangement, the entire surface of the clamping portion contacts the side surface of the coupling pin. In an exemplary embodiment, the clamping portion of each of the first and second coupling surfaces is constructed and configured to abut the side surface of the coupling pin so that substantially the entire surface of the clamping portion contacts the side surface of the coupling pin. In other words, the corresponding surfaces of the pin and the clamping portion can be constructed and configured so that almost the entire clamping portion (or the vast majority of it, i.e., more than about 50% of the relevant surface) of each of the coupling surfaces contacts the corresponding surface of the pin. In another embodiment, the pin can be cylindrical, but the coupling surface can be non-cylindrical, such as elliptical or polygonal. In the latter case, the contact surface of the clamping portion will only partially abut the cylindrical pin. The coupling surfaces, including the clamping surfaces, may be configured to influence and / or control the insertion and extraction forces that need to be applied when attaching the refill head to the handle.

[0023] The replacement head and the coupling mechanism can be configured to include a coupling insert that is disposed within the tubular portion of the replacement head and is pressed onto it. The insert has a front portion that includes an upper portion, a lower portion, and an intermediate portion between the upper portion and the lower portion, wherein the lower portion is separated from the intermediate portion by a first semicircular space, and the intermediate portion is separated from the upper portion by a second semicircular space. The lower portion may include an annular flange extending in a direction substantially perpendicular to the longitudinal axis and including an inner periphery and an outer periphery. When the replacement head is attached to the handle, the annular flange can be positioned adjacent to the handle. The inner periphery of the flange can advantageously include a recessed portion that is constructed and configured to provide space for the ribs of the coupling rod when the replacement head is attached to the handle.

[0024] The middle portion includes the pair of mutually opposing cantilever arms described above. The cantilever arms are positioned so as to be resiliently movable relative to the lower and upper portions as described above. The upper portion may include the aforementioned grooves for engaging the upper ends of ribs extending longitudinally from the coupling rod to limit axial movement of the replacement head relative to the handle when the replacement head is axially attached to the handle.

[0025] In one embodiment, the outer wall of the connecting rod and the replacement head wall form a plurality of pressure-fit sections in combination, wherein when the replacement head is attached to the handle, their opposing faces frictionally engage each other. The pressure-fit area can be arranged at any suitable location, for example adjacent to the free end of the connecting rod and / or adjacent to the end opposite to the free end of the connecting rod. Each of the pressure-fit areas can have at least two pressure-fit sections, i.e., friction contact points. In one embodiment, the plurality of pressure-fit sections include three pressure-fit sections adjacent to the free end of the connecting rod, and at least three pressure-fit sections adjacent to the end opposite to the free end of the connecting rod.

[0026] In one embodiment, the coupling insert includes at least one tolerance compensation spring extending vertically in a general direction substantially parallel to the longitudinal axis and having a free end. The tolerance compensation spring can be constructed and arranged such that when the replacement head is attached to the handle, at least a portion of the tolerance compensation spring adjacent the free end of the tolerance compensation spring resiliently biases the insert against a surface of the coupling rod, thereby providing a frictional connection therebetween.

[0027] In another embodiment, each of the cantilevers may include a curved portion and a vertical fin integrally formed with the curved portion, wherein the fin includes the aforementioned coupling surface. The curved portion has a curved length measured along the circumference, a curved height measured in a direction approximately perpendicular to the curved length, and a curved thickness measured in a direction approximately perpendicular to the curved height. In one embodiment, the curved length is greater than the curved height, and the curved height is greater than the curved thickness. In one embodiment, the vertical fin has a fin height greater than the curved height. The curved length may be from about 4 mm to about 10 mm, from about 4.5 mm to about 9 mm, and from about 5 mm to about 8 mm. The curved height may be from about 2 mm to about 8 mm, from about 2.5 mm to about 6.5 mm, and from about 3 mm to about 5 mm. The curved thickness may be from about 0.5 mm to about 2 mm, from about 0.7 mm to about 1.8 mm, and from about 0.9 mm to about 1.6 mm. The fin height may be from about 3 mm to about 12 mm, from about 5 mm to about 10 mm, and from about 6 mm to about 9 mm.

[0028] In one embodiment of a toothbrush and replacement head, the replacement head may have a motion transmitter terminating at a first magnetic coupling element, while the handle's drive mechanism terminates at a second magnetic coupling element. The first and second magnetic coupling elements may then be constructed and arranged to form a secure magnetic connection between the replacement head and the handle when the replacement head is attached, such that motion of the handle's drive mechanism is transmitted to the replacement head's motion transmitter. Such magnetic coupling elements may include one or more permanent magnets and / or one or more magnetizable elements.

[0029] The drive mechanism of the handle may be designed for linear oscillatory motion substantially along the longitudinal axis A, while the brush head may be designed for rotational oscillatory motion about an axis of rotation extending substantially perpendicular to the longitudinal axis A. Alternatively or in addition, the brush head may be designed to move in a lateral oscillatory motion about an axis extending substantially parallel to the longitudinal axis A, or any other type of motion, such as linear oscillatory motion, vibratory action, and / or other motion patterns as known in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The embodiments listed in the drawings are schematic and exemplary in nature and are not intended to limit the invention defined by the claims. The following detailed description of exemplary embodiments can be better understood when read in conjunction with the following drawings, in which similar structures are represented by similar reference numerals.

[0031] Figure 1 is a schematic axonometric view of one embodiment of an electric toothbrush.

[0032] Figure 2 yes Figure 1 Schematic axonometric view of a replacement head for the toothbrush shown.

[0033] Figure 3 yes Figure 1 Schematic axonometric view of the handle of the toothbrush shown.

[0034] Figure 4 is a schematic front view of one embodiment of a coupling device of the present disclosure.

[0035] Figure 5 yes Figure 4 Schematic axonometric view of one embodiment of the coupling device is shown.

[0036] Figure 6 As Figure 4 A schematic axonometric view of a coupling insert is shown of a part of a coupling device.

[0037] Figure 7 is a schematic front view of a fragment of a toothbrush including a coupling device of the present disclosure, showing a motion transmitter and a magnetic element for connecting the motion transmitter with a corresponding magnetic element of the handle.

[0038] Figure 8 yes Figure 6 An enlarged schematic front view of one embodiment of a coupling insert is shown.

[0039] Figure 8A yes Figure 8 A schematic cross-sectional view of the coupling insert is shown taken along line 8A-8A.

[0040] Figure 9 yes Figure 4 An enlarged schematic front view of one embodiment of the coupling device is shown.

[0041] Figure 9A is an enlarged fragmentary view of another embodiment of a coupling device.

[0042] Figure 10 is a schematic isometric view of one embodiment of a coupling device showing a press fit section for connecting a rod to a handle.

[0043] Figure 11 is another schematic isometric view of an embodiment of a coupling device illustrating a press fit section for connecting a rod to a handle.

[0044] Figure 12 is a schematic diagram of one embodiment of a replacement head without its outer housing and a portion of a handle illustrating a motion transmitter and a magnetic coupling element.

[0045] Figure 13 is a schematic axonometric illustration of an embodiment of a coupling insert with a tolerance compensation spring.

[0046] Figure 14 is a schematic cross-sectional side view of an embodiment of a coupling device comprising a coupling insert with a tolerance compensation spring elastically abutting a coupling rod of a handle. DETAILED DESCRIPTION

[0047] like Figure 1-3 As shown, the electric toothbrush 10 of the present disclosure includes a handle 20 having a longitudinal axis or longitudinal direction A and a replacement head 30. Figure 1 In the embodiment shown, the longitudinal axis A of the replacement head 30 is coincident with the longitudinal axis of the handle 20, but those skilled in the art will appreciate that in some embodiments (not shown here), the replacement head can be designed to be slightly angled relative to the handle, in which case the longitudinal axis of the replacement head may not be coincident with or parallel to the longitudinal axis of the handle. Such angled embodiments are included within the scope of the present invention.

[0048] The replacement head 30 is constructed and arranged to be connected to the Figure 4-7 ) is attached to the handle 20. The handle 20 has a drive mechanism (not shown) inside, and the replacement head 30 has a brush head 31 and a motion transmitter 32 ( Figure 8), the motion transmitter is functionally connected to the brush head 31 for driving the brush head 31. The handle 20 also includes a coupling rod 200 having an outer wall 210 extending along the longitudinal axis A and terminating at a free end 220. The coupling rod 200 has a coupling pin 230 extending therefrom in a direction non-parallel to the longitudinal axis A. Preferably, the coupling pin 230 extends from the outer wall 210 at an approximately right angle or substantially perpendicular to the longitudinal axis A.

[0049] The coupling rod 200 may advantageously include a rib 240 for coupling that protrudes outward (or radially) from the coupling rod 200 and is longitudinally oriented in a direction substantially parallel to the longitudinal axis A. The rib 240 has a first end 241 (which is located at the lower part in the figure) and a second end 242 (which is located at the upper part in the figure) opposite to the first end 241. The rib 240 may be arranged adjacent to the coupling pin 230. Figure 4 and 5 In an embodiment, the coupling pin 230 is disposed between or in the middle of the first end 241 and the second end 242 of the rib 240. The rib 240 and the coupling pin 230 may be configured to protrude outwardly from the coupling rod 200 to the same extent, i.e., the outermost surface of the rib 240 may be flush with the outermost surface (free end) of the coupling pin 230. Alternatively, the coupling pin 230 may protrude from the coupling rod 200 to a greater extent than the rib 240, in which case a portion of the coupling pin 230 extends beyond the outermost surface (free end) of the rib 240. Figure 4 、 Figure 5 ).

[0050] The replacement head 30 may include a groove 128 constructed and arranged to engage the second end 242 of the rib 240 to limit movement (axial and / or radial) of the replacement head 30 relative to the handle 20 when the replacement head 30 is axially attached to the handle 20. The size and shape of the groove 128 may be advantageously set to match the size and shape of the second end 242 of the rib 240. Figure 4 and Figure 5 In one embodiment, the second end 242 of the rib 240 is shown having a convex, generally semicircular shape; and the groove 128 is shown having a corresponding, concave, generally semicircular shape. The present disclosure contemplates other mutually corresponding shapes of the rib 240 and the groove 128. Moreover, the second end 242 of the rib 240 may have other suitable configurations, which may or may not necessarily transition in a tangential manner.

[0051] The replacement head 30 has a generally tubular portion 33 formed by a replacement head wall 34. The tubular portion 33 can have any suitable shape, including, for example, a generally cylindrical shape, a generally conical shape, or any combination thereof. As used herein, the terms "generally cylindrical" and "generally conical" describe shapes that are strictly cylindrical and conical, as well as those that deviate from strictly cylindrical and conical shapes. Examples of such "generally cylindrical" and "generally conical" tubular portions 33 include, but are not limited to, tubular portions 33 having a cross-sectional shape that deviates from a circle due to elongation in one direction (e.g., elliptical, oval, etc.). The tubular portion can also have other suitable shapes, such as polygonal, rectangular, etc. - or a combination of generally cylindrical / conical and polygonal shapes. Inside the tubular portion 33, there is an internal space defined by the replacement head wall 34 and constructed and configured to receive the connecting rod 200 of the handle 20 therein when the replacement head 30 is attached to the handle 20. The coupling device 100 includes a pair of mutually opposed cantilevered arms 150 disposed within the interior space of the replacement head 30 and adjacent the replacement head wall 34, and more specifically, adjacent the inner surface of the replacement head wall 34. The cantilevered arms 150 are curved and can be described as generally circular or semicircular, meaning that the cross-sectional shape of the cantilevered arms 150 taken in a plane substantially perpendicular to the longitudinal axis A can include circular portions, or can include portions that deviate from a perfectly circular shape—similar to the deviations from the generally cylindrical and generally conical tubular portions 33 described previously (i.e., due to elongation in one direction) to include portions that are, for example, elliptical, oval, etc.

[0052] A pair of curved cantilever arms 150 includes a first cantilever arm 150a and a second cantilever arm 150b opposite the first cantilever arm 150a. Each cantilever arm 150 has a fixed end (or "root") 151 (151a, 151b) and terminates in a free end 152 (152a, 152b). The free end 152 includes a coupling surface 153 (153a, 153b) that is constructed and configured to engage the coupling pin 230 of the coupling rod 200 for secure and detachable connection therewith. In the coupling mechanism of the present disclosure, the coupling pin 230 forms the handle coupling portion, and the coupling device 100 forms the replacement head coupling portion.

[0053] The first cantilever 150a terminates at a first coupling surface 153a, and the second cantilever 150b terminates at a second coupling surface 153b. The first coupling surface 153a is opposite and faces the second coupling surface 153b. The first and second coupling surfaces 153a, 153b are constructed and arranged to simultaneously surround the coupling pin 230 on opposite sides of the coupling pin when the replacement head 30 is attached to the handle 20.

[0054] Each of the first and second coupling surfaces 153a, 153b includes a sliding portion 154 (154a, 154b) and a clamping portion 155 (155a, 155b) adjacent to the sliding portion 154. The distance between the first sliding portion 154a and the second sliding portion 154b of the first and second coupling surfaces 153a, 153b, respectively, which are opposite to each other, can be about 0.4 mm to about 5 mm, about 0.5 mm to about 4.5 mm, and about 0.6 mm to about 3 mm. In a specific embodiment, the distance between the two mutually opposite first sliding portions 154a and second sliding portions 154b is between about 1 mm and about 2 mm. When the replacement head 30 having the coupling device 100 therein is not attached to the handle 20, that is, when the coupling device 100 is not undergoing elastic deformation as described herein, the distance can be measured as the average of the maximum distance D1 and the minimum distance D2, as Figure 8 shown.

[0055] In embodiments where the coupling pin 230 is substantially cylindrical, the diameter of the coupling pin 230 (or an equivalent dimension perpendicular to the sliding portion if the pin is not cylindrical) can be from about 0.8 mm to about 6 mm, from about 1 mm to about 5 mm, and from about 2 mm to about 4 mm. The mutually opposing clamping portions 155a, 155b of the coupling surfaces 153a, 153b can each advantageously match the outer surface of the coupling pin 230 in shape and size.

[0056] When the replacement head 30 is axially attached to the handle 20, i.e., when the replacement head 30 is axially moved relative to the handle 20 and the coupling rod 200 on which the coupling pin 230 is disposed, the coupling surfaces 153 are constructed and arranged to slidably and elastically engage the coupling pin 230 by virtue of the resilient force of the cantilever. During axial attachment, as the coupling pin 230 slides upward into elastic contact with the sliding portions 154, the coupling pin 230 contacts the mutually opposing sliding portions 154 of the coupling surface 153 on opposite sides of the pin. When the coupling pin 230 reaches the clamping portions 155, the coupling pin 230 is pulled into snap engagement with the clamping portions 155a, 155b. To facilitate positioning of the coupling pin 230 relative to the mutually opposing coupling surfaces 153 and to facilitate entry of the pin into the space between the two coupling surfaces 153, each of the sliding portions 154 may include a ramp 156. An angle α2 formed between the inclined surface 156 and the surface of the sliding portion 154 may be, for example, about 100 to 170 degrees, about 110 to 160 degrees, and about 120 to 150 degrees.

[0057] At least one of the sliding portions 154 may be angled relative to the longitudinal axis A. Figure 4 and 8In the illustrated embodiment, the two sliding portions 154 are symmetrically angled relative to the longitudinal axis A, such that the space between the opposing sliding surfaces 154 increases upward, that is, the space between the first sliding portion 154a and the second sliding portion 154b increases in the direction from the inclined surface 156 to the clamping portion 155. As the coupling pin 230 slides along the sliding portions 154 toward the clamping portion 155, this configuration facilitates pulling the coupling pin 230 into the clamping portion 155 of the coupling surface 153 due to the elasticity of the cantilever 150 and the associated pressure of the coupling surface 153 acting on the coupling pin 230. The angle α1 formed between the two opposing sliding portions 154a, 154b of the cantilever 150 can range from about 0.1 degrees to about 20 degrees, from about 1 degree to about 15 degrees, and from about 1.5 degrees to about 10 degrees. In one specific embodiment, the angle α1 is from about 2 degrees to about 3 degrees. In another embodiment, the sliding portions 154 of the first and second coupling surfaces 153 may be arranged substantially parallel to the longitudinal axis A, and thus substantially parallel to each other ( Figure 9 , showing the distance D3 between the two sliding parts 154a, 154b).

[0058] The present invention also contemplates an alternative embodiment (not shown) in which the sliding portion 154 is angled in the opposite direction relative to the longitudinal axis A, wherein the space between the two sliding surfaces 154a, 154b decreases upwardly, i.e., the space between the first sliding portion 154a and the second sliding portion 154b decreases in the direction from the inclined surface 156 to the clamping portion 155.

[0059] Figure 9A One embodiment of a clamping device is shown having two curved portions 160a and 160b that clamp the coupling pin 230. As already discussed, the curved portions 160a and 160b each have an inclined surface 154 and a sliding portion 154, but the curved portions 160a and 160b have clamping portions 155a and 155b formed by trapezoidal cutouts so that each of the clamping portions 155a and 155b always clamps the coupling pin 230 at two clamping points regardless of tolerances in the different components.

[0060] When the replacement head 30 is attached to the handle, the space or gap existing between the two mutually opposing coupling surfaces 153 of the cantilever arm 150 elastically expands—as the coupling pin 230 slides along the opposing sliding portions 154 of the coupling surfaces 153. When this occurs, the elastic (or resilient) deformation or movement of the cantilever arm 150 can include radial bending elastic deformation, i.e., elastic movement of the cantilever arm 150 away from the longitudinal axis A of the toothbrush; axial bending elastic deformation, i.e., elastic movement of the cantilever arm 150 along the longitudinal axis A of the toothbrush; torsional-twisting elastic deformation, i.e., elastic torque movement of the cantilever arm 150, in which the coupling surface 153 rotates relative to the fixed end or "root" of the arm (from which the cantilever arm 150 extends); and any combination thereof.

[0061] Because the refill head 30 is repeatedly attached to and detached from the handle 20, particularly in environments that may contain abrasive materials such as toothpaste slurry, wear is inevitable at the interface between the coupling pin 230 and the coupling surface 153. Therefore, it is advantageous to have the coupling pin 230 (which is part of the handle 20) be made of steel or other hard-surfaced, wear-resistant materials (e.g., steel, ceramic, surface-reinforced plastic, and various suitable surface coating materials), and the coupling surface 153 (which is part of the refill head 30) be made of plastic. This arrangement advantageously meets the functional and corresponding life expectancy requirements of the handle 20 and refill head 30.

[0062] The clamping portion 155 of each of the first and second coupling surfaces 153 can be constructed and configured to abut a side surface of the coupling pin 230 such that when the replacement head 30 is attached to the handle 20, substantially the entire surface of the clamping portion 155 contacts the side surface of the coupling pin 230. In other words, the corresponding surfaces of the coupling pin 230 and the clamping portion 155 can be sized and shaped such that substantially the entire clamping portion 155 of each of the first and second coupling surfaces 153a, 153b contacts the corresponding surface of the coupling pin 230 to provide a secure engagement between the handle 20 and the replacement head 30 when the replacement head 30 is attached to the handle 20.

[0063] The coupling pin 230 may have any suitable shape, such as cylindrical, prismatic, conical, or the like, but a cylindrical or conical shape may be preferred. Accordingly, the clamping portion 155 of the coupling surface 153 may also be formed to have a circular or semicircular shape, wherein the diameter of the coupling pin 230 is substantially equal to the equivalent diameter of the clamping portion 155. In such an arrangement, the entire surface of the clamping portion 155 will contact the side surface of the coupling pin 230, as described above. Because the two mutually opposing coupling surfaces 153 contacting the coupling pin 230 may have a space between them and therefore may not include a perfect circle, as used herein, the term "equivalent diameter" refers to the imaginary or theoretical diameter of the clamping portion 155 based on the radius of its respective curvature.

[0064] The replacement head 30 and the coupling device 100 may be configured to include a coupling insert 110 that is disposed within the tubular portion 33 of the replacement head 30 and is pressed-fit thereto, for example by utilizing a plurality of press-fit sections. Figure 6 1 , comprising a protrusion 111 from the outer surface of the insert. In another embodiment, the protrusion 111 may have a corresponding section, such as a corresponding recess (not shown), provided on the inner side of the tubular portion 33 of the replacement head 30. The press-fit sections may be distributed equidistantly from one another around the circumference of the interface between the tubular portion 33 and the insert 110, for example at 60 degrees.

[0065] As best shown in Figure 9 and 8A , the insert 110 may have a front section 120 including a lower portion 121, an upper portion 123, and a middle portion 122 between the lower portion 121 and the upper portion 123. The lower portion 121 and the middle portion 122 are separated by a first semicircular space 124, and the middle portion 122 and the upper portion 123 are separated by a second semicircular space 125. As used herein, the front section 120 of the insert 110 is a semicircular portion of the insert that includes two integral cantilevers from the first end 151a of the first cantilever 150a to the first end 151b of the second cantilever 150b. Figure 8A In the plan view, the front section 120 is outlined by the angle α3 formed in the plan view of the insert 110 between two planes PA and PB parallel to the longitudinal axis A, and the angle can be about 70 degrees to about 200 degrees, about 80 degrees to about 190 degrees, and about 90 degrees to about 180 degrees.

[0066] The lower portion 121 of the coupling insert 110 may include an annular flange 126 that extends in a direction substantially perpendicular to the longitudinal axis A and includes an inner periphery 126a and an outer periphery 126b. When the replacement head 30 with the coupling insert 110 incorporated therein is securely attached to the handle 20, the annular flange 126 may be positioned adjacent the handle 20 ( Figure 4 The flange 126 may advantageously include a recessed portion 127 adjacent its inner periphery 126a that is sized and shaped to provide space for the rib 240 and coupling pin 230 of the coupling rod 200 when the replacement head 30 is axially attached to the handle 20 .

[0067] Intermediate portion 122 includes the aforementioned pair of mutually opposing cantilevered arms 150. Cantilevered arms 150 are positioned so that they can resiliently move relative to lower portion 121 and upper portion 123 of coupling insert 110 as previously described. Upper portion 123 may include the aforementioned groove 128 for engaging the upper end of a rib 240 projecting outwardly from coupling rod 200 and extending longitudinally to limit radial and / or axial movement of replacement head 30 relative to handle 20 when replacement head 30 is axially attached to handle 20.

[0068] To ensure a secure connection between the replacement head 30 and the handle 20, the outer wall 210 of the coupling rod 200 and the replacement head wall can be configured to, in combination, form a plurality of press-fit sections 250, wherein corresponding opposing surfaces of the outer wall 210 and the replacement head wall frictionally engage one another when the replacement head 30 is attached to the handle 20. The press-fit sections 250 that frictionally couple the replacement head 30 to the coupling rod 200 can be provided at any suitable location, such as adjacent to the free end 220 of the coupling rod 200 and / or adjacent to the end opposite the free end 220 of the coupling rod 200. Figure 10 As shown, for example, the plurality of press-fit sections 250 may include at least three (upper) press-fit sections 251, 252, 253 adjacent the free end 220 of the coupling rod 200. The plurality of press-fit sections 250 may also include at least three (lower) press-fit sections 254, 255, 256 adjacent the end opposite the free end 220 of the coupling rod 200. The (lower) press-fit sections 254, 255, 256 may advantageously include a portion of the inner periphery 126a of the flange 126 of the lower portion 121 of the coupling insert, as best shown in FIG. Figure 11 .

[0069] exist Figure 13 and 14 In another embodiment schematically shown, the coupling insert 110 includes a tolerance compensation spring 170 extending vertically in a general direction substantially parallel to the longitudinal axis A. The tolerance compensation spring 170 can be advantageously formed (e.g., molded) as an integral part of the coupling insert. The tolerance compensation spring 170 has a free end and an inner surface 171. The tolerance compensation spring 170 is constructed and configured such that when the replacement head 30 is attached to the handle 20, at least an upper portion of the inner surface 171 of the tolerance compensation spring (i.e., the portion of the inner surface adjacent the free end of the tolerance compensation spring 170) elastically abuts an adjacent surface of the coupling rod 200, thereby providing a friction pressure fit connection therebetween. Although a single tolerance compensation spring 170 is shown herein, the present disclosure contemplates embodiments comprising two or more tolerance compensation springs of this or similar construction.

[0070] In another embodiment, each of the cantilevers 150 may include a curved portion 160 and a fin integrally formed with the curved portion 160. The fin may be oriented generally vertically. The fin includes the aforementioned coupling surface 153. The curved portion 160 has a curved length L measured in a circumferential direction, a curved height H measured at the highest (highest) portion of the curved portion 160 in a direction generally perpendicular to the curved length L, and a curved thickness W measured in a direction generally perpendicular to the curved height H, wherein the curved length is greater than the curved height H, and the curved height H is greater than the curved thickness W. Given a particular plastic material of the cantilever 150 having favorable physical properties, such as polyoxymethylene (POM) or reinforced POM, these dimensions L, W, and H may be carefully selected to facilitate elastic deformation of the cantilever 150. As previously described, such deformation may include at least one of the following: radial bending elastic deformation, i.e., elastic "unbending" movement of the cantilever 150 outward away from the longitudinal axis A; axial bending elastic deformation, i.e., elastic movement of the cantilever 150 substantially along the longitudinal axis A (i.e., up and down movement); torsional-twisting elastic deformation, i.e., elastic torque movement of the cantilever 150, in which the connecting surface 153 rotates relative to the fixed end (or "root") 151 of the arm (from which the arm extends); and any combination thereof.

[0071] The vertical fins have a fin height H1. As shown in several figures, the fin height H1 can (but is not necessarily) greater than the bend height H. In an exemplary non-limiting embodiment, the bend length can be from about 4 mm to about 10 mm, from about 4.5 mm to about 9 mm, and from about 5 mm to about 8 mm. The bend height can be from about 2 mm to about 8 mm, from about 2.5 mm to about 6.5 mm, and from about 3 mm to about 5 mm. The bend thickness can be from about 0.5 mm to about 2 mm, from about 0.7 mm to about 1.8 mm, and from about 0.9 mm to about 1.6 mm. The fin height can be from about 3 mm to about 12 mm, from about 5 mm to about 10 mm, and from about 6 mm to about 9 mm.

[0072] The replacement head 30 may include a motion transmitter 300 therein. In one embodiment, the motion transmitter 300 terminates at a first magnetic coupling element 310, while the drive mechanism of the handle 20 terminates at a second magnetic coupling element 410 ( Figure 7 ). The first and second magnetic coupling elements 310, 410 can then be constructed and configured to form a secure magnetic connection between the replacement head 30 when attached to the handle 20, such that motion of the handle's drive mechanism is effectively transmitted to the replacement head's motion transmitter 300. Such magnetic coupling elements can include one or more permanent magnets and / or one or more magnetizable elements, as described in commonly assigned U.S. Patent No. 8,631,532, the disclosure of which is incorporated herein by reference.

[0073] The drive mechanism of the handle 20 can be constructed and configured for linear oscillatory motion substantially along the longitudinal axis A, and the brush head 31 can be constructed and configured for rotational oscillatory motion about a rotation axis X extending substantially perpendicular to the longitudinal axis A, lateral oscillatory motion about an axis extending substantially parallel to the longitudinal axis A, or any other type of motion, including linear oscillatory motion, or vibratory motion, and other motion modes as known in the art.

[0074] Although specific embodiments have been illustrated and described herein, various other changes and modifications may be made without departing from the spirit and scope of the invention. Furthermore, although various aspects of the invention have been described herein, such aspects need not be utilized in combination. Therefore, it is intended that all such changes and modifications within the scope of the invention be covered in the appended claims.

[0075] The terms "substantially," "essentially," "about," and "approximately" as may be used herein represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation, as will be readily recognized by those skilled in the art. These terms also represent the degree to which a quantitative representation may vary from a stated reference value without resulting in a change in the basic function of the subject matter in question. Furthermore, the dimensions and values ​​disclosed herein, whether preceded by the terms "substantially," "essentially," "about," "approximately," and the like, are not to be construed as being strictly limited to the precise values ​​recited. Instead, unless otherwise indicated, each such dimension is intended to represent the stated value and a functionally equivalent range surrounding that value. For example, values ​​disclosed as "5 mm" and "70 degrees" are intended to mean "approximately 5 mm" and "approximately 70 degrees," respectively.

[0076] Unless expressly excluded or otherwise limited, the disclosure of each document cited herein, including any cross-referenced or related patent or application and any patent application or patent to which this application claims priority or the benefit of, is hereby incorporated by reference in its entirety. The citation of any document is not an admission that it is prior art to any disclosure of the present invention or to any claim protected herein, or that it, by itself or in combination with any other reference or references, proposes, suggests, or discloses any aspect of the invention. Further, if any meaning or definition of a term in this document conflicts with any meaning or definition of the same or similar term in a document incorporated by reference, the meaning or definition assigned to that term in this document, or implied from the context by that document, shall govern.

Claims

1. An electric toothbrush comprising a handle and a replacement head having a longitudinal axis and constructed and arranged to be attached to the handle via a coupling device, the handle having a drive mechanism and the replacement head having a brush head and a motion transmitter functionally connected to the brush head for driving the brush head, wherein the handle comprises a coupling rod having an outer wall extending in a direction substantially parallel to the longitudinal axis and terminating in a free end, the coupling rod further having a coupling pin extending therefrom in a direction non-parallel to the longitudinal axis, wherein the replacement head includes a generally tubular portion formed by replacement head walls defining an interior space therebetween, the interior space being constructed and arranged to receive the coupling rod of the handle therein when the replacement head is attached to the handle, wherein the coupling arrangement comprises a pair of mutually opposed cantilever arms disposed adjacent the replacement head wall in the interior space of the replacement head, wherein each of the cantilever arms extends and bends about the longitudinal axis in a plane substantially perpendicular thereto, is elastically deformable, and terminates in a coupling surface constructed and arranged to engage the coupling pin of the coupling rod for secure and detachable connection therewith, wherein the replacement head comprises a coupling insert having a front section, the front section comprising an upper portion, a lower portion, and an intermediate portion between the upper portion and the lower portion, wherein the lower portion is separated from the intermediate portion by a first space and the intermediate portion is separated from the upper portion by a second space, wherein the lower portion is adjacent to the handle when the replacement head is attached to the handle, wherein the intermediate portion comprises the pair of mutually opposing cantilevered arms, and wherein the upper portion comprises a groove constructed and configured to engage an upper end of a rib extending longitudinally from the coupling rod of the handle, thereby limiting axial movement of the replacement head relative to the handle when the replacement head is axially attached to the handle.

2. The electric toothbrush according to claim 1, wherein the coupling pin extends in a direction substantially perpendicular to the longitudinal axis.

3. An electric toothbrush according to claim 1 or 2, wherein the connecting rod of the handle includes a rib protruding from the connecting rod and adjacent to the connecting pin, the rib having a lower end, an upper end opposite to the lower end, and a rib length between the lower end and the upper end, and the rib is longitudinally oriented to be substantially parallel to the longitudinal axis. 4 . The electric toothbrush according to claim 3 , wherein the coupling pin is provided between the lower end and the upper end of the rib.

5. An electric toothbrush according to claim 1 or 2, wherein the pair of mutually opposing cantilevers terminating at coupling surfaces include a first cantilever terminating at a first coupling surface and a second cantilever terminating at a second coupling surface opposite to and facing the first coupling surface, and wherein the first coupling surface and the second coupling surface are constructed and configured to simultaneously surround the coupling pin at opposite sides of the coupling pin when the replacement head is attached to the handle.

6. The electric toothbrush of claim 5, wherein the first coupling surface and the second coupling surface are constructed and arranged to slidably and resiliently engage the coupling pin when the refill head is axially attached to the handle.

7. The electric toothbrush of claim 3, wherein the replacement head includes a groove constructed and arranged to engage the upper end of the rib of the coupling rod to thereby limit axial movement of the replacement head relative to the handle when the replacement head is axially attached to the handle.

8. The electric toothbrush of claim 1, wherein the mutually opposed cantilever arms are constructed and arranged to resiliently move relative to the lower portion and the upper portion of the coupling insert.

9. An electric toothbrush according to claim 1, wherein the connecting insert includes at least one tolerance compensation spring extending outward in the general direction of the longitudinal axis, wherein the tolerance compensation spring has a free end and is constructed and configured so that when the replacement head is attached to the handle, at least a portion of the tolerance compensation spring adjacent the free end of the tolerance compensation spring elastically biases the connecting insert against the connecting rod to provide a friction pressure fit contact therebetween.

10. The electric toothbrush of claim 1 or 2, wherein the outer wall of the coupling stem and the replacement head wall in combination form a plurality of press-fit sections wherein opposing faces frictionally engage one another when the replacement head is attached to the handle.

11. An electric toothbrush according to claim 10, wherein the pressure-fit section is provided in a first pressure-fit area adjacent to the free end of the connecting rod and in a second pressure-fit area adjacent to the end opposite to the free end of the connecting rod, and each of the first pressure-fit area and the second pressure-fit area includes multiple pressure-fit sections.

12. The electric toothbrush of claim 1 or 2, wherein the motion transmitter of the replacement head terminates in a first coupling element and the drive mechanism of the handle terminates in a second coupling element, and wherein the first coupling element and the second coupling element are constructed and configured to form an operative connection therebetween when the replacement head is attached to the handle.

13. The electric toothbrush of claim 12, wherein the first coupling element comprises a first magnetic coupling element and the second coupling element comprises a second magnetic coupling element, and wherein the first magnetic coupling element and the second magnetic coupling element are constructed and configured to form a magnetic connection therebetween when the replacement head is attached to the handle.

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