Pressure sensing electric shaver

Abstract

Embodiments of the present disclosure relate to a pressure sensing electric shaver. The electric shaver has a shaving unit and a sensor having a first sensor unit fixed to a main body and a second sensor unit fixed to a sensor unit carrier for indicating the distance between the sensor units. The shaving unit and the sensor unit carrier are suspended from the main body for shifting between a rest position and a push-in position along the z-axis in response to a thrust applied to a shaving face of the shaver. The first sensor unit and the second sensor unit are located in a position offset from the z-axis within a distance along the x-direction. An anti-tilt guide is provided for guiding the sensor unit carrier to prevent tilting about the y-axis.

Description

Technical Field

[0001] The present invention relates to a shaver. Such a shaver is known from WO 2015 / 025064. Background Art

[0002] During shaving, users generally try to achieve a clean shave in a short time while avoiding skin irritation and skin damage. When the hair cutting member is in too close contact with the skin, skin irritation and damage occur, especially when the user presses the hair cutting member against the skin with excessive force. This can occur during the use of a manual wet shaver and during the use of an electric shaver (razor). In particular, users who have just switched from one system to another system or inexperienced users often have difficulty in following the shape of the body part to be shaved while pressing the shaving head against the skin with a pressure within a suitable pressure range. Suitable pressure ranges can also vary with skin thickness.

[0003] US5983502A discloses a shaver in which the pressure against the skin is measured by measuring the extent to which a hair cutting unit (sometimes referred to as a shaving head) is pressed into a hair cutting body. If the sensor signals that the inward displacement of the hair cutting unit is too great, a signal is generated to warn the user that the shaving pressure applied is too high. The sensor of each hair cutting unit comprises: an annular permanent magnet, which is fixed to a coupling pin; and a Hall sensor, which is arranged below the magnet and fixed in the body.

[0004] However, the inward displacement of the cutting unit is limited and is used to a large extent to adapt the orientation of the cutting unit to the curvature of the skin surface being shaved by tilting the cutting unit relative to the hair cutting body. Therefore, the indication of the applied pressure is also affected by tilting the hair cutting unit while adapting to the curvature of the skin being shaved, and the displacement range that can be used for pressure measurement is reduced by allowing the displacement range required for the tilting.

[0005] In the shaver according to WO2015 / 025064, this problem has been solved by measuring the shaving pressure based on the displacement and tilting of the hair cutting body (which includes the cutting unit) relative to the main body. This allows the cutting unit to be tilted and pressed in while adapting to the shape of the skin without interfering with the shaving pressure measurement. However, the shaver according to WO2015 / 025064 with shaving pressure signaling is relatively complex and expensive to manufacture. Moreover, the suspension is relatively large in the radial direction. Summary of the invention

[0006] It is an object of the present invention to provide a shaver which provides an accurate indication of the shaving pressure but is of simpler and more compact construction.

[0007] According to the invention, this object is achieved by providing a shaver.

[0008] Since, in addition to the elastic member, an anti-tilt guide is provided for guiding at least the sensor unit carrier relative to the body against tilting about at least the y-axis perpendicular to the x-axis and the z-axis, a tilting which seriously affects the distance between the first sensor unit and the second sensor unit in the z-direction is at least greatly reduced. Thus, the displacement of the shaving unit and thus the applied force causing the applied shaving pressure can be measured without being affected or only slightly affected by the tilting of the shaving unit by a simple sensor, which only needs to be arranged and configured for measuring the distance between the first sensor unit and the second sensor unit in the direction of the z-axis and can be conveniently positioned a distance away from the z-axis in the x-direction, wherein even in a compact shaver, space is available for accommodating the sensor units.

[0009] The anti-tilt guide may allow the sensor unit carrier to tilt about an x-axis perpendicular to the y-axis and the z-axis, and may allow the sensor unit carrier to pivot about the z-axis. The anti-tilt guide may generally allow a certain amount of play and / or elasticity, so that the tilting about the y-axis is greatly reduced by the anti-tilt guide, but not necessarily completely eliminated.

[0010] Further features, effects and details of the present invention become apparent from the detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a partially cut-away side view of an example of a shaver according to the present invention;

[0012] Figure 2 yes Figure 1 A cross-sectional view of the top portion of the body of the shaver shown in FIG.

[0013] Figure 3 is a side view of a sensor unit carrier and a guide for relative Figure 1 and Figure 2 to guide at least the sensor unit carrier through the main body of the shaver shown in FIG.

[0014] Figure 4 yes Figure 3 A top plan view of the sensor unit carrier and guide shown in FIG.

[0015] Figure 5 yes Figure 3 and Figure 4 A perspective view of the sensor unit carrier and guide shown in FIG.

[0016] Figure 6is a top plan view of a suspension spring for forming an arm of an alternative example of a guide for a shaver according to the present invention;

[0017] Figure 7 is a perspective view of another example of a sensor unit carrier and a guide for a shaver according to the present invention; and

[0018] Figure 8 is a cross-sectional perspective view of yet another example of a sensor unit carrier and a guide of a shaver according to the present invention. DETAILED DESCRIPTION

[0019] Figure 1 An example of a shaver 1 according to the invention is shown. Figure 1 The shaver 1 shown in FIG. 1 has a body 2 which is adapted to be held by a user of the shaver. Figure 1 In the figure, for simplicity, the main body 2 and the components in the main body are shown schematically. The shaver 1 also has a shaving unit 3, which is suitable for contacting the skin area with the hair to be shaved and can be moved appropriately over the area so as to slide over the skin. In this example, the shaving unit 3 is moved by Figure 2 The central coupling member 4 shown in FIG. 1 is connected to the main body 2, which shows the top end portion 5 of the main body 2. Figure 2 , the shaving unit 3 is detached from the main body 2 and is therefore not shown. The cross-sectional dimensions of the central coupling member 4 are significantly smaller than those of the shaving unit 3, and the shaving unit 3 is positioned at a distance from the top end portion 5 of the main body 2. Thus, the connection between the main body 2 and the shaving unit 3 has a slim appearance, and the shaving unit 3 has an elevated position relative to the main body 2, so that in use, the main body 2 minimally obscures the shaving unit 3 from view.

[0020] The shaving unit 3 has three cutting units 6 (only two of which are located in the Figure 1), the three cutting units are arranged in a triangular form and exposed on the shaving surface 11 of the shaver 1. The number of cutting units can also be two or more than three. The cutting unit 6 can be arranged so as to be movable to a certain extent, so that the cutting unit 6 can be pushed into a configuration that adapts to the curved or flat contour of the skin area to be shaved. For example, the cutting unit 6 can be individually depressible to a limited extent relative to the cutting unit carrier 9, and thus can be tilted, and the cutting unit 6 is supported relative to the main body 2 via the cutting unit carrier. Each cutting unit 6 has a cap-shaped external cutting element 8, which forms the outer surface of the cutting unit 6 and has a plurality of openings for allowing hair to pass through and be shaved. The external cutting elements 8 are each depressible relative to the cutting unit carrier 9, and thus can be tilted. The internal cutting element 7 is rotatably arranged directly inside each cap-shaped external cutting element 8. During operation, the cutting edge of the internal cutting element 7 is pressed against the cap-shaped external cutting element 8 under the action of the spring force, and each cutting edge slides along the inner surface of an associated one of the external cutting elements 8. The shaving face 11 is not necessarily flat, as in the present example, and the cutting unit 6 may face slightly different converging or diverging directions when in the rest position and adapt to the shape of the skin surface being shaved when tilted during shaving.

[0021] In the present example, the cutting unit carrier 9 is also connected to the body 2 via a main drive shaft 12 for jointly driving the internal cutting member 7 of the cutting unit 6 via gears (not shown). The main drive shaft 12 is coupled to a motor 13 in the body 2. A gear 18 on the drive shaft 12 is engaged by a drive gear 14 on an output drive shaft 19 of the motor 13. A coupling member 4 engages a coupling member of a central gear (not shown) which engages the gears. Although the cutting unit in the present example has an internal cutting element which is in rotational motion when the shaver is in use, the present invention is also applicable to shavers having cutting elements which have internal cutting elements which move linearly back and forth between a first end position and a second end position in an oscillating manner.

[0022] In order to supply power to the motor 13, a battery 42 is provided, and the battery is connected to a motor controller 43, which controls the supply of power to the motor 13 connected to the motor controller 43. The motor controller 43 may be provided with a switch for receiving a control input from a user.

[0023] The shaving unit 3 is suspended from the body 2 for displacement along a z-axis oriented transversely to the shaving face 11 from a rest position (as shown) toward the body 2 to a position greater than or equal to the shaving face 11 in response to a thrust applied to the shaving face 11 of the shaver 1. Figure 1The position shown in FIG. is slightly closer to the pushed-in position of the body 2. The shaving unit 3 is connected to a sensor unit carrier 22 on which the second sensor unit 17 is mounted, so that the shaving unit 3 and the sensor unit carrier move in unison in the z-direction. In this example, the coupling member 4 is part of the sensor unit carrier 22 and is arranged for coupling to the cutting unit carrier 9 of the shaving unit 3.

[0024] The shaving unit may be fully or partially tiltable relative to the sensor unit carrier to allow easy adaptation of the orientation of the shaving face to the orientation of the skin surface to be shaved. Alternatively, the shaving unit may be fixed relative to the sensor unit carrier and, instead of being detachable as in the present example, the shaving unit may be permanently fixed to the sensor unit carrier or formed integrally with the sensor unit carrier. Furthermore, although in the present example the sensor unit carrier 22 is part of the body 2, it may instead be part of the shaving unit.

[0025] The sensor 15 has a first sensor unit 16 and a second sensor unit 17, the first sensor unit is mounted in a fixed position relative to the body 2, and the second sensor unit 17 is mounted in a fixed position relative to the sensor unit carrier 22. The first sensor unit 16 and the second sensor unit 17 are offset from the z axis by a distance d, and the distance d is along the x direction perpendicular to the z direction. The sensor 15 also has a signal processing unit 20 and a sound generator 21, the signal processing unit 20 is connected to the first sensor unit 16, and the sound generator 21 is connected to the output port of the signal processing unit 20. The sensor 15 is arranged and configured to output a signal indicating the distance of the second sensor unit 17 to the first sensor unit 16. In this example, the first sensor unit 16 is a Hall sensor, and the second sensor unit 17 is a magnet. Other types of distance sensor units are also conceivable, such as optical sensors or inductive sensors as described in WO2015 / 025064. Instead of or in addition to the sound generator, other signal output devices can be used. The generated warning signal may be human perceptible, or of a type to be received by a receiver of a signal processing device which generates a human perceptible warning signal in response to receiving a warning output signal from a signal output transmitter of the shaver, preferably in real time or near real time.

[0026] As in Figures 2 to 5 As can be seen in FIG. 2 , the elastic members 24, 25, 26, 27 interconnect the pillars 28, 29 fixed to the body 2 with the sensor unit carrier 22. These elastic members are shaped and dimensioned to apply a force along the z-axis, which is along the push-in position 22' (see FIG. 2 ). Figure 2 ) biases the shaving unit 3 and the cutting unit carrier 9 as well as the sensor unit carrier 22 towards the rest position 22.

[0027] The elastic members 24, 25, 26, 27 are shaped and dimensioned so that the sensor unit carrier 22 moves out of the rest position 22 into the pushed-in position 22' (see FIG. 2 ) only in response to a force applied to the shaving surface 11 in the z-direction. Figure 2 ), which force corresponds to a pressure applied to the skin during shaving which is greater than is desirable to avoid skin irritation due to excessive protrusion of the skin into the opening in the skin guard 8 of the hair cutting unit 6. Such movement into the pushed-in position results in a significant reduction in the distance in the z-direction between the first sensor unit 16 and the second sensor unit 17 and thus in a change in the received distance signal output from the first sensor unit 16 to the signal processing unit 20. The signal processing unit is arranged to generate and output a sound signal to the sound generator 21 if the received distance signal is below a preset value which is slightly higher than a value associated with the distance in the z-direction between the first sensor unit 16 and the second sensor unit 17 if the sensor unit carrier 22 is in the pushed-in position 22'. The sound generator 21 is arranged to generate an easily audible warning signal in response to the sound signal received from the signal processing unit 20. Thus, applying a force of such magnitude in the z-direction that a shaving pressure is applied via the shaving face 11 (which exceeds the desirable maximum shaving pressure) causes the sensor unit carrier 22 to be pushed into the push position 22' and causes a warning signal to be generated by the sound generator 21. This warns the user that too much force and therefore too much shaving pressure has been applied. After a period of time, the user will learn what force can be applied without causing an excessive shaving pressure alarm.

[0028] Conversely, the measured displacement and thus the force applied in the z-direction can also be used to detect the application of a force that is too low to generate a shaving pressure high enough to achieve a clean shave. In response to a shaving pressure that is too low, a second warning signal can be generated to warn the user that more pressure should be applied if a clean shave is to be achieved.

[0029] In the present example, the second (or first) arm of each pair of arms 24, 25 and 26, 27 constitutes an anti-tilting guide for guiding the sensor unit carrier 22 relative to the body 2 to prevent tilting about a y-axis perpendicular to the x-axis and the z-axis during movement of the shaving unit 3 along the z-axis between the rest position 22 and the pushed-in position 22'. Each pair of arms 24, 25 and 26, 27 provides a guide with a high degree of rigidity to prevent tilting about the axis in the y-direction.

[0030] Due to the greatly reduced tilting of the sensor unit carrier 22 about the y-axis, the disturbance of the distance between the first sensor unit 16 and the second sensor unit 17 caused by the tilting is greatly reduced. Since the first sensor unit 16 and the second sensor unit 17 are offset from the z-axis within a distance d in the x-direction, the tilting of the sensor unit carrier 22 about the y-axis will cause the second sensor unit 17 to move in a predominantly z-direction, so that in practice the full movement of the second sensor unit 17 due to such tilting will be in the z-direction and thus in the direction of measuring the distance between the first sensor unit 16 and the second sensor unit 17. By greatly reducing the tilting about the y-axis, such a large influence of the tilting on the distance between the first sensor unit 16 and the second sensor unit 17 is avoided.

[0031] For example, if the stiffness of the elastic member along the z-direction is such that the ratio between the force applied along the z-direction from the rest position toward the pushed-in position and the displacement along this direction is between 10 N / mm and 16 N / mm, and / or the force required to press the cutting unit carrier 9 completely into the pushed-in position is between 4 N and 10 N, the total stiffness achieved in the presence of the anti-tilt guide to prevent tilting about the y-axis is preferably such that the ratio between the friction force applied to the shaving surface 11 and the displacement of the second sensor unit 17 along the z-direction (due to the tilting about the y-axis) is greater than 15 N / mm, and more preferably greater than 20 N / mm.

[0032] Preferably, the cutting unit carrier 9 carrying the hair cutting unit 6 is tiltable relative to the sensor unit carrier 22 so as to allow the hair cutting unit 6 and the shaving surface 11 to be tilted relative to the sensor unit carrier 22 without causing a displacement of the sensor unit carrier 22 along the z-axis relative to the body 2. Thus, tilting the hair cutting unit 6 to adapt the orientation of the shaving surface 11 to the orientation of the skin being shaved can be achieved without significantly affecting the shaving pressure reading in the form of a signal output by the first sensor unit 16 to the signal processing unit 20.

[0033] The main drive shaft 12 has a rotation axis extending centrally between the cutting units 6 along the z-axis. Thus, the rotation driven by the motor 13 can be evenly distributed to the cutting units 6 in a simple manner. Furthermore, by arranging the drive shaft 12 centrally along the z-axis of the shaving unit 3, the cutting unit carrier 9 and the sensor unit carrier 22, the drive shaft 12 conveniently extends centrally through these parts, while the z-axis also extends centrally between the cutting units 6. Thus, a shaving pressure evenly distributed throughout the cutting units 6 is applied along the z-axis and thus does not result in a bending moment being applied about the z-axis. In practice, the resultant force of the aggregated shaving pressure extends along a line that will move around in a region around the central z-axis, wherein the z-axis is centrally between the cutting units 6, and the maximum bending moment applied is also kept to a minimum.

[0034] In the present example, first suspension arms 24, 26 are attached to the body 2 at first positions 31, 35 and to the sensor unit carrier 22 at second positions 32, 36. The arms 24, 26 each extend between the first position 31, 35 and the second position 32, 36. In this suspension, an anti-tilting guide is provided in a very effective and in principle frictionless manner by second suspension arms 25, 27, which are attached to the body 2 at a third position 33 (one position not visible in any of the figures) and to the sensor unit carrier 22 at a fourth position 34, 38. These arms 25, 27 also extend between the third position 33 and the fourth position 34, 38. In a plane parallel to the z-axis, all suspension arms are elastically deformable, more particularly bendable.

[0035] The first position 31, 35 and the third position 33 are spaced apart from each other within a first distance, which has at least one component in a direction parallel to the z-axis. The second position 32, 36 and the fourth position 34, 38 are spaced apart from each other within a second distance, which also has at least one component in a direction parallel to the z-axis. The length of the component of the first distance in a direction parallel to the z-axis is equal to the length of the component of the second distance in a direction parallel to the z-axis. Thus, a suspension of the sensor unit carrier 22 is obtained, which is flexible in the z-direction, but has a large rigidity to prevent tilting about the y-axis, and also has sufficient rigidity to prevent tilting about the x-axis and pivoting about the z-axis. Although tilting about the x-axis and pivoting about the z-axis affect the distance between the first sensor 16 and the second sensor 17 to a much lesser extent than tilting about the y-axis, the rigidity to prevent such tilting and pivoting also helps to avoid interference with the measurement of shaving pressure in the z-direction.

[0036] In the present example, the suspension comprises two first suspension arms 24, 26 and two second suspension arms 25, 27. Providing at least two first suspension arms 24, 26 or at least two second suspension arms 25, 27 is advantageous for further counteracting tilting and pivoting about the z-axis, in particular if relatively slender suspension arms are provided in view of the limited space available adjacent to the sensor unit carrier 22.

[0037] Furthermore, the two first suspension arms 24, 26 and the two second suspension arms 25, 27 are located on opposite sides of a plane defined by the x-axis and the z-axis. Thus, a generally symmetrical arrangement of the suspension arms 24, 26 and 25, 27 is obtained, wherein the two first suspension arms 24, 26 and the two second suspension arms 25, 27 can be arranged far apart but closely along the cutting unit carrier 9.

[0038] To obtain further anti-tilting guidance in a compact configuration, the two first suspension arms 24, 26 and the two second suspension arms 25, 27 are interconnected by a bridge 37 which is fixedly connected to the interconnected pair of suspension arms 24, 26 and 25, 27. This further increases the stiffness of the combined suspension arms against tilting.

[0039] The two first suspension arms 24, 26 and the two second suspension arms 25, 27 diverge towards or away from a plane defined by the y-axis and the z-axis, so that the suspension is also rigid against translational displacement in the y-direction transverse to the z-axis.

[0040] In order to achieve a particularly high stiffness against tilting about the y-axis with a compact construction, the first position 31, 35 and the third position 33, at which the suspension arms 24-27 are attached to the body 2, are positioned on a common side of a plane defined by the y-axis and the z-axis, so that the arms 24, 25 and 26, 27 of each pair and the elements 22, 28 and 29 to which these arms are connected form a parallelogram in the plane along the z-direction and the general x-direction, and thus provide a high stiffness against tilting. The distance between the elastic members 24, 25 and 26, 27 can be, for example, 5 to 10 mm.

[0041] For particularly accurate guidance in the z direction, it is furthermore advantageous to position the first locations 31 , 35 and the third location 33 at which the suspension arms 24 - 27 are attached to the body 2 in a plane parallel to the plane defined by the y-axis and the z-axis.

[0042] In the present example, anti-tilt guidance is achieved in a particularly simple manner and without play in the suspension, since the first suspension arm 24, 26 and the second suspension arm 25, 27 are provided in the form of flat leaf springs, each having a length in the direction from the first position 31, 35 to the second position 34, 36 or from the third position 33 to the fourth position 34, 38 (where the arms are fixedly attached) and a width in a direction parallel to the y-axis. These effects can be achieved to a lesser extent (only for the individual arms) by providing only one or more of the arms in the form of such leaf springs.

[0043] The leaf springs are preferably relatively flexible for allowing the sensor carrier 22 to move in the z-direction while being sufficiently rigid in a plane perpendicular to the z-direction to provide sufficiently accurate guidance to limit movement in directions other than the z-direction. To this end, the flat leaf springs preferably each have a bending stiffness in a plane perpendicular to the z-axis that is at least three times, and more preferably at least five times or at least seven times, the bending stiffness of the leaf spring in a plane parallel to the z-axis.

[0044] The rotation axis of the main drive shaft 12 passes between the suspension arms 24, 25 and 26, 27 of each pair of suspension arms. Thus, a compact construction is achieved, since the elongated suspension arms extend on opposite sides along the sensor unit carrier 22. Furthermore, the distance in the x-direction between the fixed attachments 31, 33, 35 to (the struts 29, 29 of) the body 2 and the mean force centre of the shaving pressure (which is along the rotation axis of the main drive shaft 12) is much shorter than the length of the suspension arms 24-27, which are also oriented mainly in the x-direction. Therefore, while a sufficiently long suspension arm 24-27 can be accommodated to provide the amount of spring travel required to push the sensor unit carrier 22 from the pushed-in position 22' to the rest position 22 while applying a fairly constant force, the distance in the x-direction between the fixed attachment 31, 33, 35 to the body 2 and the average force center of the shaving pressure can be much shorter than the length of the suspension arm 24-27, so that tilting about the y-axis as a result of the bending moment applied to the suspension arm 24-27 is further reduced.

[0045] In the present example, a particularly simple construction with a relatively small number of parts is also achieved, because the leaf springs forming the anti-tilt guides 24, 26 or 25, 27 also constitute the elastic member that pushes the sensor unit carrier 22 from the pushed-in position 22' to the rest position 22. Likewise, in other embodiments of the present invention, it is advantageous for simplicity of construction and for reducing the number of parts if the spring member forming the anti-tilt guide also forms the elastic member that pushes the sensor unit carrier 22 from the pushed-in position 22' to the rest position 22.

[0046] For reliable operation of the shaver 1, in particular if the shaver 1 is also arranged for wet shaving, it is advantageous, as in the present example, for the first sensor unit 16 to be mounted in a position shielded from the environment by a shield 39 so as to separate it hermetically and dust-free from the environment. The second sensor unit 17 is mounted in a position outside this shield 39. This allows the mobile sensor unit carrier 22 to be arranged completely outside the shield 39 and moving parts for transferring movements in the z-direction to measure such movements do not have to extend through the shield 39, so that the need to seal such moving parts against the shield is avoided.

[0047] exist Figure 6 , an alternative spring member 124 is shown, which may be provided in place of Figures 1 to 5By providing two such spring members 124 in a coaxial arrangement with a spacing in the z-direction and with an outer periphery 131 fixedly attached relative to the body and a central part 132 of a thus designed pattern attached to the sensor unit carrier, a suspension is obtained which provides both an elastic member for urging the cutting unit carrier to its rest position and a guide in the form of the first or second spring member 124 against tilting about the y-axis.

[0048] exist Figure 7 In FIG. 1 , a suspension of a sensor unit carrier 222 of a further example of a shaver according to the invention is shown. In this example, the upper suspension arms 224, 226 of the suspension arms 224, 225 and 226, 227 are provided in the form of substantially rigid arms, which are articulated at attachment locations 231, 232, 235, 236 at the ends of the arms 224, 226. In this example, the upper arms 224, 226 form an anti-tilt guide. As in FIG. Figures 1 to 5 In the example shown in , the lower suspension arms 225, 227 are provided in the form of leaf springs and also form elastic members. However, in this example, the lower suspension arms 225, 227 are integrally formed with a bridging portion 240 located between the suspension arms 225, 227, which is at the side of the suspension arms 225, 227 fixed to the pillar 228 of the main body 202. The hinged suspension arms 224, 226 are also integrally formed with a bridging portion 241. The bridging portion is also located at the side of the suspension arms 224, 226 connected (here hinged) to the pillar 228 of the main body 202. The bridging portion formed integrally with the suspension arm may also or alternatively be provided at the side of the suspension arm connected to the sensor unit carrier 222. A particular advantage of forming the bridge portion integrally with the suspension arms is that a particularly rigid connection between the suspension arms is achieved and the two upper or lower suspension arms form a single part, which facilitates assembly and handling of the parts.

[0049] exist Figure 8 , a further example of a suspension in a shaver according to the present invention is shown, which is used to suspend the sensor unit carrier 322 relative to the main body 302. In this example, the elastic member is composed of Figure 6 324 is formed by a spring member 324 similar to the spring member shown in . At its periphery 331, the spring member 324 is fixed to the annular protrusion 329 of the main body 302. The anti-tilt guide is provided in the form of a ring 326, which has a cylindrical inner wall surface that is in close sliding contact with the cylindrical outer wall surface of the sensor unit carrier 322. The cylindrical outer wall surface of the ring 326 is in close sliding contact with the cylindrical inner wall surface of the annular protrusion 329 of the main body 302. Therefore, the sensor unit carrier 322 is telescopically guided relative to the main body 302, so that the tilt of the sensor unit carrier 322 is offset.

[0050] Although in the example shown the resilient member is a spring, other forms of resilient members are also contemplated, such as a pair of mutually repelling magnets or a pneumatic cylinder.

[0051] While the invention has been described and illustrated in detail in the foregoing description and drawings, such description and illustration are to be considered exemplary and / or illustrative and not restrictive; the invention is not limited to the disclosed embodiments.

[0052] Several features have been described as part of the same or separate embodiments. However, it will be appreciated that the scope of the invention also includes embodiments having combinations of all or some of these features in addition to the specific combinations of features embodied in the examples. Other variations of the disclosed embodiments can be understood and implemented by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "one" or "an" does not exclude a plurality. A single processor or other unit may implement the functions of several items recited in the claims. For the purpose of clarity and concise description, features are disclosed herein as part of the same or separate embodiments; however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the disclosed features. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference numerals in the claims should not be interpreted as limiting the scope.

Claims

1. An electric shaver, comprising: Subject (2; 202; 302), and A shaving unit (3) having at least two cutting units (6) exposed to a shaving surface (11) of the shaver, each cutting unit (6) being mounted to a cutting unit carrier (9) of the shaving unit (3) and comprising an outer cutting guard (8) and an inner cutting member (7), A sensor (15) comprising a first sensor unit (16) and a second sensor unit (17), wherein the first sensor unit is mounted in a fixed position relative to the body (2; 202; 302); and the second sensor unit is mounted in a fixed position relative to a sensor unit carrier (22; 222; 322), wherein the sensor (15) is arranged and configured to output a signal indicating a distance from the second sensor unit (17) to the first sensor unit (16) in a direction parallel to a z-axis, wherein the z-axis is positioned transversely to the shaving surface (11), wherein the shaving unit (3) and the sensor unit carrier (22; 222; 322) are suspended from the main body (2; 202; 302) for being uniformly displaced along the z-axis from a rest position (22) toward the main body (2; 202; 302) to a pushed-in position (22') in response to a thrust force applied to the shaving surface (11) of the shaver (1), wherein an elastic member is provided between the body (2; 202; 302) and the shaving unit (3) for applying a force along the z-axis, the force biasing the shaving unit (3) in a direction from the pushed-in position towards the rest position, wherein the first sensor unit (16) and the second sensor unit (17) are located in a position offset from the z-axis by a distance (d), the distance being in a direction parallel to an x-axis extending perpendicular to the z-axis, The invention is characterized in that the elastic member comprises an anti-tilt guide (24-27; 124; 224, 226; 326; 328) for guiding at least the sensor unit carrier (22; 222; 322) relative to the body (2; 202; 302) to prevent the shaving unit from tilting about at least a y-axis extending perpendicularly to the x-axis and the z-axis during movement of the shaving unit along the z-axis between the rest position (9) and the pushed-in position (9').

2. A shaver according to claim 1, wherein the cutting unit carrier (9) carrying the cutting unit (6) is capable of tilting relative to the sensor unit carrier (22; 222; 322) so as to allow the cutting unit (6) to tilt relative to the sensor unit carrier (22; 222; 322) without causing at least a displacement of the sensor unit carrier (22; 222; 322) relative to the body (2; 202; 302) along the z-axis.

3. A shaver according to claim 1, wherein the cutting unit carrier (9) is releasably connected to the sensor unit carrier (22; 222; 322) by means of a releasable connecting structure, the connecting structure comprising a first connecting member mounted to the cutting unit carrier (9), and a second connecting member mounted to the sensor unit carrier (22; 222; 322).

4. A shaver according to any one of the preceding claims, wherein the cutting unit carrier (9) is also connected to the main body (2; 202; 302) via a main drive shaft (12) for jointly driving the internal cutting member (7) of the cutting unit (6).

5. A shaver according to claim 4, wherein the main drive shaft (12) has an axis of rotation extending centrally between the cutting units (6) along the z-axis.

6. A shaver according to any one of the preceding claims, further comprising a first suspension arm (24, 26; 224, 226) attached to the body (2) at a first position (31, 35; 231, 235) and to the sensor unit carrier (22; 222) at a second position (32, 36; 232, 236), the arm (24, 26; 224, 226) extending between the first position (31, 35; 231, 235) and the second position (32, 36; 232, 236); wherein the anti-tilt guide comprises a second suspension arm (25, 27; 225, 227) which is attached to the body (2) at a third position (33) and to the sensor unit carrier (22; 222) at a fourth position (34, 38), the second suspension arm (25, 27; 225, 227) extending between the third position (33) and the fourth position (34, 38); wherein the first suspension arm (24, 26; 224, 226) and the second suspension arm (25, 27; 225, 227) are elastically deformable in a direction parallel to the z-axis; wherein the first position (31, 35; 231, 235) and the third position (33) are spaced apart from each other within a first distance, the first distance having at least one component along a direction parallel to the z-axis, the second position (32, 36; 232, 236) and the fourth position (34, 38) are spaced apart from each other within a second distance, the second distance having at least one component along a direction parallel to the z-axis, wherein the component of the first distance along the direction parallel to the z-axis has a length, the length being equal to the length of the component of the second distance along the direction parallel to the z-axis.

7. A shaver according to claim 6, comprising two first cantilever frames in the first cantilever arm (24, 26; 224, 226) and / or two second cantilever frames in the second cantilever arm (25, 27; 225, 227).

8. A shaver according to claim 7, wherein the two first suspension arms (24, 26; 224, 226) and / or the two second suspension arms (25, 27; 225, 227) are located on opposite sides of a plane defined by the x-axis and the z-axis.

9. A shaver according to claim 7 or 8, wherein the two first suspension arms (24, 26; 224, 226) and / or the two second suspension arms (25, 27; 225, 227) are interconnected by a bridge member (37; 240, 241), and the bridge member is fixedly connected to the first suspension arm (24, 26; 224, 226) and / or the second suspension arm (25, 27; 225, 227), or is integrally formed with the first suspension arm (24, 26; 224, 226) and / or the second suspension arm (25, 27; 225, 227).

10. A shaver according to any one of claims 7 to 9, wherein the two first suspension arms (24, 26; 224, 226) and / or the two second suspension arms (25, 27; 225, 227) diverge towards or away from each other when viewed in a plane extending parallel to the x-axis and the y-axis.

11. A shaver according to any one of claims 6 to 10, wherein the first position (31, 35; 231, 235) and the third position (33) are located on a common side of a plane defined by the y-axis and the z-axis.

12. A shaver according to claim 10, wherein the first position (31, 35; 231, 235) and the third position (33) are located in a plane parallel to the plane defined by the y-axis and the z-axis.

13. A shaver according to any one of claims 6 to 12, wherein at least one of the first suspension arm (24, 26; 224, 226) and the second suspension arm (25, 27; 225, 227) is a flat leaf spring, which has a length in a direction from the first position to the second position or from the third position to the fourth position, and has a width in a direction parallel to the y-axis.

14. The shaver of claim 13, wherein the flat leaf spring has a bending stiffness in a plane perpendicular to the z-axis that is at least three times the bending stiffness of the leaf spring in a plane parallel to the z-axis.

15. A shaver according to claim 8, wherein the cutting unit carrier (9) is also connected to the main body (2; 202; 302) via a main drive shaft (12) for jointly driving the internal cutting members (7) of the cutting units (6), wherein the main drive shaft (12) has a rotation axis extending centrally between the cutting units (6) along the z-axis, and wherein the rotation axis of the main drive shaft (12) extends between the two first suspension arms (24, 25 and 26, 27) and / or between the two second suspension arms.

16. A shaver according to any one of the preceding claims, wherein the first sensor unit (16) is mounted in a position shielded from the environment by a shield (39), and wherein the second sensor unit (17) is mounted in a position outside the shield (39).

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