Patent Publication Number: US-11654586-B2

Title: Shaving apparatus

Description:
This application is a National Phase of PCT Patent Application No. PCT/IL2020/050079 having International filing date of a Jan. 19, 2020, which claims the benefit of priority of U.S. Provisional Patent Application No. 62/795,153, filed Jan. 22, 2019 and U.S. Provisional Patent Application No. 62/806,020, filed Feb. 15, 2019, the contents of which are all incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     There are several different types of devices that men and women use to shave body hair. These include disposable razors, electric razors, cartridge razors, safety razors, and straight razors. Electric razors also come in different types, including foil-style electric razors and rotary-style electric razors. In a foil-style electric razor, a thin, perforated, protective metal screen is provided that covers the blades. The blades are sharp reciprocating or oscillating blades that move side-to-side at very high speed behind the protective metal screen. The user&#39;s hairs pass through openings in the protective metal screen (which is stationary) and are then cut as the blades oscillate back and forth. In a rotary-style electric razor, there are several circular screens that have an internally spinning cutter blade that cuts the hairs captured by the stationary circular screens. The rotary-style electric razor works similarly to a weed wacker. The circular heads are designed to follow the contours of the user&#39;s skin as the razor is moved thereacross. 
     Existing electric razors have several undesirable side effects, including reduced closeness of the shave when compared to manual razors and skin irritation. Such skin irritation is caused by the mechanical abrasion of rubbing the foil screen against the skin and friction heat transfer to the skin due to the inner blades rubbing against the outer screen. Thus, a need exists for an improved electric razor. 
     SUMMARY 
     The present invention is directed to a shaving apparatus having a head portion intended for contact with a skin surface to cut hairs growing therefrom. The head portion may include a screen and a cutting component located beneath the screen. The screen may include a plurality of openings so that a user&#39;s hairs can pass therethrough to be cut by blades of the cutting component. The screen may be rotatable about a rotational axis so that as the screen is placed into contact with a skin surface and moved therealong, the screen is made to rotate about the rotational axis. The shaving apparatus may include a power source and an electric motor operably coupled to the power source and to the cutting component. Thus, the cutting component may oscillate along a cutting axis to cut the hairs that pass through the openings in the screen. 
     In one aspect, the invention may be a cylindrical screen comprising an outer surface, an inner surface defining a cavity, and a plurality of openings, the screen being rotatable about a rotational axis; a cutting component comprising one or more cutting blades located within the cavity of the cylindrical screen, the cutting blades positioned adjacent to the inner surface of the cylindrical screen to cut hairs that pass through the openings in the cylindrical screen; wherein upon placing the outer surface of the cylindrical screen into surface contact with a skin surface and moving the shaving apparatus along the skin surface, the cylindrical screen rotates about the rotational axis; and a brake sub-system configured to reduce a rotational velocity of the cylindrical screen to cause relative motion between the cylindrical screen and the skin surface as the shaving apparatus is moved along the skin surface. 
     In another aspect, the invention may be a head portion of a shaving apparatus comprising: a mounting portion; a cylindrical screen comprising a plurality of openings, the cylindrical screen rotatably coupled to the mounting portion so as to be rotatable about a rotational axis; a brake sub-system configured to intermittently reduce a rotational velocity of the cylindrical screen; and a cutting component comprising one or more cutting blades, the cutting component configured to cut hairs that pass through the openings in the cylindrical screen. 
     In yet another aspect, the invention may be a method of shaving comprising: pressing a cylindrical screen of a shaving apparatus into contact with a skin surface, the cylindrical screen comprising a plurality of openings that allow hairs on the skin surface to pass through the cylindrical screen; moving the shaving apparatus along the skin surface while the cylindrical screen is in surface contact with the skin surface, thereby causing the cylindrical screen of the shaving apparatus to rotate about a rotational axis; intermittently reducing a rotational velocity of the cylindrical screen with a brake sub-system that is operably coupled to the cylindrical screen; and cutting the hairs that pass through the cylindrical screen with a cutting component. 
     According to some embodiments, there is provided herein a shaving apparatus comprising: a cylindrical screen comprising an outer surface, an inner surface defining a cavity, and a plurality of openings, the screen being rotatable about a rotational axis; a cutting component comprising one or more cutting blades located within the cavity of the cylindrical screen, the cutting blades configured to cut hairs that pass through the openings in the cylindrical screen; wherein upon placing the outer surface of the cylindrical screen into surface contact with a skin surface and moving the shaving apparatus along the skin surface, the cylindrical screen rotates about the rotational axis; and a brake sub-system configured to reduce a rotational velocity of the cylindrical screen to cause relative motion between the cylindrical screen and the skin surface as the shaving apparatus is moved along the skin surface. 
     According to some embodiments, there is provided herein a head portion of a shaving apparatus comprising: a mounting portion; a cylindrical screen comprising a plurality of openings, the cylindrical screen rotatably coupled to the mounting portion so as to be rotatable about a rotational axis; a brake sub-system coupled to the cylindrical screen and configured to intermittently reduce a rotational velocity of the cylindrical screen; and a cutting component comprising one or more cutting blades, the cutting component configured to cut hairs that pass through the openings in the cylindrical screen. According to some embodiments, the cylindrical screen is configured to rotate about the rotational axis, relative to the mounting portion, in response to a linear force being applied thereto. 
     According to some embodiments, the cylindrical screen may be a foil screen having a thickness of less than about 0.1 mm, for example, less than about 0.09 mm, less than about 0.075 mm or less than about 0.05 mm. 
     According to some embodiments, the shaving apparatus may further include a head portion comprising the cylindrical screen and the cutting component and a handle portion coupled to the head portion and configured for gripping by a user. 
     According to some embodiments, the shaving apparatus may further include a power source; and an electric motor operably coupled to the power source and to the cutting component to oscillate the cutting component along a cutting axis to cut hairs that pass through the openings in the cylindrical screen. According to some embodiments, the power source and the electric motor are located within the handle portion. 
     According to some embodiments, the head portion may further include a mounting portion, the cylindrical screen rotatably coupled to the mounting portion. 
     According to some embodiments, the cylindrical screen may be freely rotatable relative to the mounting portion. 
     According to some embodiments, the cylindrical screen is not operably coupled to a motor. 
     According to some embodiments, the cylindrical screen may be made to rotate about the rotational axis manually due to a linear movement of the shaving apparatus along the skin surface. 
     According to some embodiments, the brake sub-system may include an activation mechanism operable by a user. The activation mechanism may include a push button. Such that, for example, in operation, when the user wishes to reduce or stop the rotational velocity of the cylindrical screen (to cause relative motion between the cylindrical screen and the skin surface), they press the push button and when the wish to allow the rotation of the cylindrical screen, they release the button. 
     According to some embodiments, the activation mechanism may be located on a head portion or on a handle portion coupled to the head portion of the shaving apparatus. 
     According to some embodiments, there is provided herein a method of shaving comprising: pressing a cylindrical screen of a shaving apparatus into contact with a skin surface, the cylindrical screen comprising a plurality of openings that allow hairs on the skin surface to pass through the cylindrical screen; moving the shaving apparatus along the skin surface while the cylindrical screen is in surface contact with the skin surface, thereby causing the cylindrical screen of the shaving apparatus to rotate about a rotational axis; intermittently reducing a rotational velocity of the cylindrical screen with a brake sub-system that is operably coupled to the cylindrical screen; and cutting the hairs that pass through the cylindrical screen with a cutting component. 
     According to some embodiments, the method may further include powering a motor of the shaving apparatus to cause the cutting component of the shaving apparatus to oscillate along a linear axis to facilitate cutting of the hairs by the cutting component. 
     According to some embodiments, there is intermittent relative motion between the cylindrical screen and the skin surface as the shaving apparatus is moved along the skin surface. 
     According to some embodiments, the intermittent relative motion between the cylindrical screen and the skin surface is operated and controlled by the user. 
     According to some embodiments, the cylindrical screen rotates about the rotational axis entirely due to the movement of the shaving apparatus along the skin surface while the cylindrical screen is in surface contact with the skin surface. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG.  1    is a perspective view of a shaving apparatus in accordance with an embodiment of the present invention; 
         FIG.  2    is an exploded perspective view of the shaving apparatus of  FIG.  1   ; 
         FIGS.  3 A and  3 B  are cross-sectional views of a head portion of the shaving apparatus taken along line of  FIG.  1    positioned adjacent to a skin surface illustrating an oscillating movement of a cutting blade of the shaving apparatus; 
         FIG.  4    is a close-up view of the head portion of the shaving apparatus of  FIG.  1    illustrating movement a screen of the shaving apparatus as the shaving apparatus moves across a skin surface; 
         FIGS.  5 A and  5 B  are cross-sectional views taken along line V-V of  FIG.  4    illustrating the movement of the screen of the shaving apparatus as the shaving apparatus moves across the skin surface; 
         FIG.  6    is a perspective view of a shaving apparatus in accordance with another embodiment of the present invention, the shaving apparatus including a cylindrical screen and a brake sub-system; 
         FIG.  7    is a schematic illustration of the shaving apparatus of  FIG.  6   ; 
         FIGS.  8 - 13    illustrate alternative brake sub-systems for the shaving apparatus of  FIG.  6   ; 
         FIGS.  14 - 16    illustrate systems for achieving relative motion between a cylindrical screen of a shaving apparatus and a skin surface; 
         FIG.  17    illustrates a shaving apparatus having a cylindrical screen with linear motion; and 
         FIGS.  18  and  19    illustrate a cylindrical screen and brake sub-system of a shaving apparatus in accordance with yet another embodiment of the present invention. 
         FIGS.  20  and  21    illustrate another embodiment of a brake sub-system. 
     
    
    
     DETAILED DESCRIPTION 
     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     The description of illustrative embodiments according to principles of the present invention is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments of the invention disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation unless explicitly indicated as such. Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Moreover, the features and benefits of the invention are illustrated by reference to the exemplified embodiments. Accordingly, the invention expressly should not be limited to such exemplary embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features; the scope of the invention being defined by the claims appended hereto. 
     Referring first to  FIGS.  1  and  2   , a shaving apparatus  100  is illustrated in accordance with an embodiment of the present invention. The shaving apparatus  100  generally comprises a handle portion  110  and a head portion  120 . The handle portion  110  is the part that is gripped by a user during shaving and the head portion  120  is the portion that performs the cutting operation. The head portion  120  may be permanently or detachably coupled to the handle portion  110 . 
     In the exemplified embodiment, the shaving apparatus  100  is an electrically operated device that includes a power source  101  and an electric motor  102  that are operably coupled together. Of course, the invention is not to be so limited and the shaving apparatus  100  could be a manual device in other embodiments. Furthermore, an electric motor and/or power source may not be required in all embodiments. The power source  101  may be batteries or similar devices that are capable of supplying power to the electric motor  102 . In the exemplified embodiment, the power source  101  is located within the handle portion  110  of the shaving apparatus  100 . However, the invention is not to be so limited in all embodiments and the power source  101  could be located within the head portion  120  or within another component or housing. Furthermore, in still other embodiments the shaving apparatus  100  may not include an internal power source, but may instead include a plug that is configured to be plugged into a wall outlet for powering the electric motor. 
     In the exemplified embodiment, the electric motor  102  is also located within the handle portion  110  of the shaving apparatus  100 . However, in other embodiments the electric motor  102  could be located within the head portion  120  of the shaving apparatus  100 . Regardless of the exact location and positioning of the electric motor  102  and the power source  101 , they should be operably coupled together so that power from the power source  101  can be transmitted to the electric motor  102  to facilitate its operation. 
     In the exemplified embodiment, an actuator  103  is located on the handle portion  110  for activating the electric motor  102 . Specifically, in the exemplified embodiment the actuator  103  is a button located on the handle portion  110  that upon being depressed by a user will activate and deactivate the electric motor  102 . Thus, pressing the actuator  103  a single time will activate the electric motor  102  by transmitting power from the power source  101  to the electric motor  102  and pressing the actuator  103  a second time will deactivate the electric motor  102 . Although depicted as a depressible button in the exemplified embodiment, the actuator  103  can take on other forms such as being a slide switch, a conductive switch, a dial switch, a pressure switch, a temperature switch, a toggle switch, a rotary switch, or the like. 
     The head portion  120  of the rotary cutter  100  comprises a mounting portion  125 , a screen  130  and a cutting component  150 . In the exemplified embodiment, the mounting portion  125  of the head portion  120  is formed integrally with the handle portion  110  and the screen  130  and the cutting component  150  are not integral with the handle portion  110  but are separately coupled to the mounting portion  125 . In other embodiments, the mounting portion  125  may be detachable from the handle portion  110 . 
     The mounting portion  125  comprises features and/or structures that facilitate the mounting of the screen  130  and the cutting component  150  thereto. Specifically, in the exemplified embodiment the mounting portion  125  comprises a first mounting protuberance  126  and a second mounting protuberance  127 . Each of the first and second mounting protuberances  126 ,  127  interact with the screen  130  to mount the screen to the mounting portion  125 . 
     In the exemplified embodiment, the screen  130  is a foil screen, which may be formed from a metal material such as aluminum or the like. Furthermore, in the exemplified embodiment the screen  130  is in the shape of a cylinder. In that regard, the screen  130  comprises an outer surface  131  that comes into contact with a user&#39;s skin during shaving, an inner surface  132 , and a plurality of openings or perforations  133  extending through the screen  130  from the outer surface  131  to the inner surface  132 . The screen  130  further comprises an inner cavity  135  that is bounded by the inner surface  132 . Thus, the screen  130  forms a hollow cylindrical shape with the openings  133  providing passageways from the exterior environment into the inner cavity  135 . The screen  130  extends from a first end  136  to a second end  137 . In the exemplified embodiment, both of the first and second ends  136 ,  137  are open. 
     In the exemplified embodiment, the plurality of openings  133  all have the same shape, which is the shape of a hexagon, and more specifically an elongated hexagon. However, the invention is not to be so limited and the openings  133  can take on any shape including circular, triangular, pentagonal, octagonal, or the like. Furthermore, in some embodiments the openings  133  may have a variation in shape such that some of the openings  133  are circular in shape while others of the openings  133  are polygonal in shape. Thus, the openings  133  can take on any shape so long as they permit a user&#39;s hairs to pass through the openings  133  and into the inner cavity  135  for cutting by the cutting component  150  which, as described below, is located within the inner cavity  135 . 
     The first and second mounting protuberances  126 ,  127  of the mounting portion  125  are positioned within the openings in the first and second ends  136 ,  137  of the screen  130  to mount the screen  130  to the mounting portion  125 . More specifically, in the exemplified embodiment a first end cap  138  is positioned within the inner cavity  135  of the screen  130  at the first end  136  of the screen  130  and a second end cap  139  is positioned within the inner cavity  135  of the screen  130  at the second end  137  of the screen  130 . The first and second mounting protuberances  126 ,  127  are received within openings in the first and second end caps  138 ,  139 . The screen  130  is not otherwise fixed to the mounting portion  125 , and thus the screen  130  is free to rotate relative to the mounting portion  125  about a rotational axis B-B. Thus, for example, if a user were to place their finger against the screen  130  and flick their finger in a downward or upward motion, the screen  130  would rotate about the rotational axis B-B relative to the mounting portion  125 , which would remain stationary. 
     The cutter component  150  is the component of the shaving apparatus  100  that cuts the user&#39;s hairs upon contact therewith. Specifically, the cutter component  150  comprises a plurality of cutting blades  151  that are capable of cutting a user&#39;s hair during operation of the shaving apparatus  100  as described more fully herein below. In the exemplified embodiment the cutter component  150  is located within the inner cavity  135  of the screen  130 . The cutter component  150  extends along a cutting axis A-A from a first end  152  thereof to a second end  153  thereof. 
     The cutter component  150  comprises a central bore  154  that extends therethrough. The head portion  120  of the shaving apparatus  100  comprises an elongated rod  121  that is located within the central bore  154  for mounting the cutter component  150  to the mounting portion  125 . The elongated rod  121  extends through openings in the first and second mounting protuberances  126 ,  127  of the mounting portion  125  as best shown in  FIG.  3 A . As will be described in greater detail below with reference to  FIGS.  3 A and  3 B , the cutter component  150  oscillates back-and-forth along the cutting axis A-A when the shaving apparatus  100 , and more particularly the motor  102  thereof, is activated. 
     Referring to  FIGS.  3 A and  3 B , the oscillatory or reciprocal movement of the cutter component  150  during shaving or other hair cutting operations will be described.  FIGS.  3 A and  3 B  illustrate the shaving apparatus  100  in position for cutting of a user&#39;s hair such that the screen  130  is in surface contact or immediately adjacent to a skin surface  190  of a user from which hairs  191  that are desired to be cut are growing or otherwise extending. As seen, the hairs pass through the openings  133  in the screen and into the inner cavity  135  of the screen  130  where they can be engaged by the cutting blades  151  of the cutting component  150 . 
     When the motor  102  is activated, the cutting component  150  is caused to oscillate back-and-forth repetitively along the cutting axis A-A. Thus, looking from  FIG.  3 A  to  FIG.  3 B , it can be seen that the cutting component  150  has moved linearly to the right in the direction of the cutting axis A-A as depicted by the arrow labeled X. The cutting component  150  will then move linearly to the left and continue to move linearly back-and-forth in an oscillating or reciprocal manner so long as the motor  102  remains activated. As the user moves the shaving apparatus  100  along the skin surface  190 , more of the hairs  191  will pass through the openings  133  in the screen  130  and be cut by the cutting blades  151  of the cutting component  150 .  FIG.  3 B  illustrates the hairs seen in  FIG.  3 A  having been cut but the cutting blades  151  of the cutting component  150 . 
     Thus, in the exemplified embodiment the motor  102  causes the cutting component  150  to move back and forth for cutting of hairs. However, the invention is not to be so limited in all embodiments. In other embodiments, the cutting component  150  may be moved/driven by a solenoid instead of an electric motor. In other embodiments, the cutting component  150  may be automatically moved in a manual way merely by moving the shaving apparatus  100  across a skin surface during shaving. Thus, for example, gears or the like may be included such that as the shaving apparatus  100  moves across the face, such movement causes the cutting component  150  to move for the cutting of hairs. Basically any technique now known or later discovered may be used for the cutting of hairs with the cutting component. 
       FIG.  4    illustrates the head portion  120  of the shaving apparatus  100  positioned against the skin surface  190  of a user. There is a vertical arrow labeled Y indicating the movement direction of the head portion  120  of the shaving apparatus  100  along the skin surface  190 . Furthermore, there is an arrow labeled Z indicating the rotational movement of the screen  130  along the rotational axis B-B. In some embodiments, the rotational axis B-B of the screen  130  may be the same axis as the cutting axis A-A of the cutting component  150 . 
       FIGS.  5 A and  5 B  illustrate the rotational movement of the screen  130  in a schematic manner. Specifically, as shown in those figures, the screen  130  is in contact with the skin surface  190  from which hairs  191  are protruding. As the shaving apparatus  100  is moved in the direction of the arrow labeled Y, the screen  130  rotates about the rotational axis B-B in the direction indicated by the arrow labeled Z (i.e., counterclockwise). If the shaving apparatus  100  were moved in the opposite direction, the screen  130  would rotate in the opposite rotational direction (i.e., clockwise). 
     At the same time, the cutting component  150  oscillates back-and-forth along the cutting axis A-A to cut the hairs  191  that are passing through the openings  133  in the screen  130 . Thus, the screen  130  is not stationary, and therefore the screen  130  is not being dragged across the skin surface  190  during shaving. Instead, the screen  130  rotates about the rotational axis B-B as the shaving apparatus  100  moves across the skin surface so that there is no relative motion between the screen  130  and the skin surface  190  during use. As a result, skin irritations can be reduced if not eliminated altogether. Furthermore, the amount of heat that is transferred to the skin due to the interaction between the cutting blades  151  and the screen  130  is reduced. This is because the heat generated by the friction between the cutting blades  151  and the screen  130  dissipates around the entire circumference of the screen  130  instead of being built up at the same area of the screen as occurs with existing designs in which the screen is stationary. 
     Thus, generally, upon placing the screen  130  into surface contact with the skin surface  190  and moving the head portion  120  of the shaving apparatus  100  linearly along the skin surface  190 , the screen  130  will rotate about the rotational axis B-B. It should be appreciated that the screen  130  is not operably coupled to the motor  102 . Thus, the screen  130  is not moving in an automatic way, but rather in a manual way due to the movement of the head portion  120  of the shaving apparatus  100  along the skin surface  190 . Furthermore, it should be appreciated that in some embodiments the shaving apparatus  100  need not move linearly along the skin surface  190  to cause rotation of the screen  130 . 
     Thus, with references to  FIGS.  3 A-B  and  5 A-B, a method of shaving or cutting hair using the shaving apparatus  100  will be briefly described. First, the motor  102  is powered on, such as by depressing or otherwise activating the actuator  103 . This powering of the motor  102  causes the cutting component  150  and the cutting blades  151  thereof to oscillate along the cutting axis A-A. Either before the motor  102  is powered on or after, the screen  130  of the shaving apparatus  100  is pressed into contact with the skin surface  190 . The skin surface  190  may be a user&#39;s leg, arm, underarm, face, head, or the like. Specifically, the skin surface  190  can be any surface of a user&#39;s skin from which hair is growing or otherwise extending and which is desired to be cut or trimmed. 
     As the screen  130  of the shaving apparatus  100  is pressed into contact with the skin surface  190 , hairs  191  on the skin surface  190  will pass through the openings  133  in the screen  130  and into the inner cavity  135  of the screen  130 . These hairs  191  that pass into the inner cavity  135  are then cut by the cutting blades  151  of the cutting apparatus  150  as the cutting apparatus  150  oscillates as described herein. Next, the shaving apparatus  100  is moved along the skin surface  190 , preferably but not necessarily in a linear direction. As this occurs, the screen  130  of the shaving apparatus  100  rotates about the rotational axis B-B due to the rotational coupling between the screen  130  and the mounting portion  125  of the head portion  120  of the shaving apparatus  100 . Because the screen  130  rotates as described herein, there is no relative motion between the screen  130  and the skin surface  190  and irritation to the skin surface  190  can be reduced or eliminated. 
       FIGS.  6 - 21    build on the description above, by including features such as relative motion between a screen and a skin surface, partial rolling, mixed rolling, and rolling/skidding. This will be described in greater detail below. 
       FIGS.  6  and  7    depict a shaving apparatus  200  having a cylindrical screen  230  having an inner surface that defines a cavity. The inner surface and cavity are not shown, but it should be appreciated that the description of the shaving apparatus  100  above is applicable for these features. The cylindrical screen  230  is generally identical to the screen  130  described above. A cutting component is located within the cavity of the cylindrical screen  230  much like with the previously described embodiments. Thus, the details of the cylindrical screen  230  and the cutting component will not be provided below, it being understood that the description above is entirely applicable. 
     The cylindrical screen  230  may have a thickness, measured between the inner and outer surfaces thereof, of less than 0.1 mm, and more specifically between 0.03 mm and 0.07 mm. This allows a user to get a very close shaving using the shaving apparatus  200 . The cylindrical screen  230  is rotatable about a rotational axis just like the cylindrical screen  230 . However, in this embodiment of the shaving apparatus  200 , there is an additional feature that can alter the rotational velocity of the cylindrical screen  230  even if the linear velocity of the cylindrical screen  230  across the skin surface that is being shaved is not changed. 
     The shaving apparatus  200  comprises a brake sub-system  250  that is configured to reduce the rotational velocity of the cylindrical screen  230  even as a user moves the cylindrical screen  230  linearly across a skin surface (such as a face) at a constant speed. In the exemplified embodiment, the brake sub-system  250  comprises a disc  251  and a brake member  252 . In the exemplified embodiment, the brake member  252  is a spring, although the invention is not to be so limited in all embodiments. The disc  251  is coupled to the cylindrical screen  230  so that as the cylindrical screen  230  rotates, so too does the disc. As seen in the figures, the disc  251  has an outer surface with alternating raised portions and valley portions. The brake member  252  has a spring force that forces the brake member  252  into contact with the outer surface of the disc  251 . As the disc  251  rotates (due to the rotation of the cylindrical screen  230  as it is dragged across a skin surface), the distal portion of the brake member  252  enters into and out of the valleys of the outer surface of the disc  251 . This causes the rotational velocity of the cylindrical screen  230  to be intermittently reduced even as the cylindrical screen  230  is moved across the skin surface at a constant speed. As a result, the cylindrical screen  230  will intermittently: (1) roll along the skin surface as it is moved across the skin surface such that there is no relative movement between the cylindrical screen  230  and the skin surface; and (2) skid or drag along the skin surface as it is moved across the skin surface such that there is relative movement between the cylindrical screen  230  and the skin surface. In some embodiments, the cylindrical screen  230  may constantly rotate as it is moved across the skin surface, but the rotational velocity will change depending on whether the brake member  252  is in contact with a valley or raised portion of the disc  251 . 
     Using the brake sub-system  250  described herein, it is possible to either reduce the rotational velocity of the cylindrical screen  230  or to temporarily stop the rotation of the cylindrical screen  230  even as the cylindrical screen  230  continues to be dragged across the skin surface. When the cylindrical screen  230  is rotating freely without any skid or forces applying a brake to it, this is best for shaving upright hairs (those that extend perpendicularly or close to perpendicularly from the skin surface). When the cylindrical screen  230  is rotating at a reduced rotational velocity or not rotating at all so that there is relative movement between the cylindrical screen  230  and the skin surface as the cylindrical screen  230  is moved across the skin surface, this is better for shaving flat hair. Thus, the invention described herein allows for a combination of rotating the cylindrical screen  230  freely so that there is no relative movement between the cylindrical screen  230  and the skin surface and rotating the cylindrical screen  230  at a reduced rotational velocity (or not rotating the cylindrical screen at all) so that there is relative movement between the cylindrical screen  230  and the skin surface. This achieves the best shaving result for both upright hairs and the hairs that lie flat against the skin surface. 
       FIGS.  8 - 13    illustrate alternative brake sub-systems that can be used in conjunction with the teachings set forth herein. Each of the brake sub-systems causes some sort of friction, either continuous or intermittent, between a disc and a brake member. 
     Referring first to  FIG.  8   , a brake sub-system  260  comprising a disc  261  and a brake member  262  is illustrated. The brake sub-system  260  is an alternative to the brake sub-system  250  depicted in  FIGS.  6  and  7   . Thus, the brake sub-system  260  can be used in the shaving apparatus  200  by replacing the brake sub-system  250  with the brake sub-system  260 . As such, although not illustrated in  FIG.  8   , the disc  261  is coupled to the cylindrical screen  230  so that the disc  261  rotates along with the cylindrical screen  230 . The disc  261  comprises an inner surface having alternating recesses and protrusions. 
     The brake member  262  is located within the interior of the disc  261  that is defined by the inner surface of the disc  261 . The brake member  262  is stationary and does not rotate along with the cylindrical screen  262 . Thus, as can be appreciated, as the disc  261  rotates about a rotational axis, opposing ends of the brake member  262  will alternatingly be in contact with the inner surface of the disc  261  and not in contact with the inner surface of the disc  261 . When the opposite ends of the brake member  262  are not in contact with the inner surface of the disc  261 , the disc  261  and also the cylindrical screen to which it is attached, will rotate freely as they are moved along a skin surface. When the opposite ends of the brake member  262  are in contact with the inner surface of the disc  261 , the friction between the brake member  262  and the disc  261  will retard the rotational velocity of the disc  261  (and the cylindrical screen). Thus, the rotational velocity of the disc  261  and the cylindrical screen will be intermittently reduced depending on whether the opposing ends of the brake member  262  are aligned with the protrusions or the recesses in the inner surface of the disc  261 . 
     Referring to  FIG.  9   , a brake sub-system  270  is illustrated. The brake sub-system  270  is very similar to the brake sub-system  260 . The brake sub-system  270  comprises a disc  271  that is coupled to the cylindrical screen and a brake member  272  that is in frictional contact with an inner surface of the disc  271 . The difference is that in this embodiment one of the ends of the brake member  272  is always in contact with the inner surface of the disc  271 . Thus, when a first end of the brake member  272  is in contact with the inner surface of the disc  271 , the second end of the brake member  272  is not, and vice versa. As a result, the rotational velocity of the disc  271  and the cylindrical screen to which it is attached is constantly retarded or reduced. Thus, there will always be some relative movement between the cylindrical screen and the skin surface as the cylindrical screen is moved across the skin surface because the rotation of the cylindrical screen is constantly being reduced due to the frictional engagement between the disc  271  and the brake member  272 . 
     Referring to  FIG.  10   , a brake sub-system  280  is illustrated. The brake sub-system  280  comprises a disc  281  that is coupled to the cylindrical screen and a brake member  282  that is in frictional contact with a surface of the disc  281 . The disc  281  will rotate along with the cylindrical screen and the brake member  282  is stationary. In this embodiment, the disc  281  comprises a plurality of spaced apart detents along one of its surfaces. Furthermore, the brake member  282  comprises a protuberance that intermittently nests within one of the detents as the disc  281  rotates. When the protuberance of the brake member  282  is located within one of the detents, a greater force may be required to cause the disc  281  and the cylindrical screen coupled thereto to rotate. Thus, the interaction between the brake member  282  and the disc  281  of the brake sub-system  280  may reduce the rolling speed of the cylindrical screen and/or may intermittently stop rotation of the cylindrical screen even as it is moved across the skin surface. 
     Referring to  FIG.  11   , yet another brake sub-system  290  is illustrated. The brake sub-system  290  comprises a disc  291  that is coupled to the cylindrical screen and a brake member  292  that is in contact with an inner surface of the disk  291 . The disc  291  will rotate along with the cylindrical screen. The disc  291  has a gear-like inner surface with spaced apart bumps/ridges. The brake member  292  may be generally stationary. As the cylindrical screen is moved across a user&#39;s skin, the cylindrical screen and the disc  291  will rotate about a rotational axis. During that rotation, the brake member  292  will contact the bumps/ridges on the inner surface of the disc  291  to reduce the rotational velocity of the cylindrical screen and the disc  291 . Thus, the brake sub-system  290  will either intermittently slow or stop the rotation of the cylindrical screen as it is being used to shave a skin surface as has been described herein. 
     Referring to  FIG.  12   , another brake sub-system  300  is illustrated. The brake sub-system  300  comprises a disc  301  that is coupled to the cylindrical screen and a brake member  302  that is used to slow or stop rotation of the disc  301  and/or cylindrical screen. In this embodiment, the disc  301  comprises an outer surface having a series of spaced apart bumps/ridges. Furthermore, the brake member  302  comprises a spring-loaded ball member. As the disc  301  rotates during use of the shaving apparatus, the spring loaded ball member will ride along the outer surface of the disc  301 . When the spring-loaded ball member is located within the valleys of the outer surface of the disc  301 , it may slow the rotational velocity of the disc  301  and hence also the cylindrical screen to which the disc  301  is coupled. 
       FIG.  13    illustrates a brake sub-system  310  that is similar to the brake sub-system  300 . The brake sub-system  310  includes a disc  311  and a brake member  312 . The brake member  312  contacts an inner surface of the disc  311  rather than an outer surface as with the brake sub-system  300 . Otherwise, the description of the brake sub-system  300  is applicable to the brake sub-system  310 . 
     Referring to  FIG.  14   , a shaving system  320  is illustrated, in part.  FIG.  14    illustrates a first cylindrical screen  310  comprising a first gear  322 , a second cylindrical screen  323  comprising a second gear  324 , and an idler  325  coupled to the first and second gears  322 ,  324 . The first and second cylindrical screens  321 ,  323  form a part of a shaving apparatus, such as the shaving apparatus  100  or the shaving apparatus  200 . Thus, although the shaving apparatus is not illustrated in  FIG.  14   , it should be readily appreciated how the first and second cylindrical screens  321 ,  323  would be used on a shaving apparatus. As can be seen, each of the first and second cylindrical screens  321 ,  323  is a hollow cylindrical structure having a cavity. In the fully assembled apparatus, a cutting component such as described above is located within the cavity for cutting hairs that pass through the apertures formed through the first and second cylindrical screens  321 ,  323 . 
     In this embodiment, the first gear  322  may be the driver gear and the second gear  234  may be the follow or driven gear. Thus, as the first cylindrical screen  321  and the first gear  322  rotate about a rotational axis, they will drive the second cylindrical screen  323  and the second gear  324  to rotate due to the coupling of the idler  325  to the first and second gears  322 ,  324 . Thus, as shown in the drawing, the first gear  322  may have more teeth ( 21  teeth) than the second gear  324  ( 17  teeth). In this embodiment, the first cylindrical screen  321  engages the skin surface during use and the first cylindrical screen  321  is made to rotate as the first cylindrical screen  321  is moved along the skin surface. There is nothing impeding the rotation of the first cylindrical screen  321  so the first cylindrical screen  321  will have no motion relative to the skin surface. 
     The rotation of the first gear  322  will cause the second gear  324  and the second cylindrical screen  323  to rotate. However, the second cylindrical screen  323  will rotate slower than the first cylindrical screen  321  because the second gear  324  has fewer teeth than the first gear  323 . A similar result can be achieved by varying the diameter of the first and second cylindrical screens  321 ,  323  such that the first cylindrical screen  321  has a smaller diameter than the second cylindrical screen  323 , which will cause the first cylindrical screen  321  to rotate faster than the second cylindrical screen  323 . In any event, this set up will result in the second cylindrical screen  323  rotating with relative motion to the skin surface to enhance the shaving of hairs that are more flat on the skin surface. In this instance both of the first and second cylindrical screens  321 ,  323  are rotating, but one is rotating slower than the other. 
       FIG.  15    illustrates a similar shaving system  330  that uses three cylindrical screens and two gears instead of two cylindrical screens and one gear. 
       FIG.  16    illustrates a shaving system  340  that includes multiple cylindrical screens, whereby one of the cylindrical screens is not aligned with the other two. Specifically, the shaving system  340  comprises a first cylindrical screen  341 , a second cylindrical screen  342 , and a third cylindrical screen  343 . The first cylindrical screen  341  rotates about a first axis X-X, the second cylindrical screen  342  rotates about a second axis Y-Y, and the third cylindrical screen  343  rotates about a third axis Z-Z. In this embodiment, the first and third axes X-X, Z-Z are parallel to one another, but the second axis Y-Y is non-parallel (i.e., oblique) to the first and third axes X-X, Z-Z. Because the second cylindrical screen  342  is not aligned with the moving direction of the shaving apparatus during use, the second cylindrical screen  342  will skid/drag along the skin surface making it more effective at shaving hairs that are flatter on the skin surface with the first and third cylindrical screens  341 ,  343  will not skid/drag making them more effective at shaving hairs that are sticking generally straight out from the skin surface. 
       FIG.  17    illustrates a shaving apparatus  350  in accordance with another embodiment of the present invention. The shaving apparatus  350  comprises a cylindrical screen  351  similar to that which has been described in the previously described embodiments as well as a cutter component that is not shown in these figures.  FIG.  17    illustrates an embodiment whereby the cylindrical screen  351  may be configured to move side-to-side linearly in the direction of its rotational axis. Thus, the cylindrical screen  351  may be configured to rotate as described previously, and in this embodiment the cylindrical screen  351  may also be configured to move side-to-side as shown with the arrows. 
     In such an embodiment, the rotation of the cylindrical screen  351  along the face by itself may not achieve optimal hair cutting because there is no relative motion between the cylindrical screen  351  and the skin surface because the cylindrical screen  351  rotates as it is moved linearly along the skin surface. Thus, by adding in a side-to-side movement, the cylindrical screen  351  will, in fact, move relative to the skin surface for a more optimal shaving, particularly of the hairs that are laying more flat on the skin surface. 
       FIGS.  18  and  19    illustrate a cylindrical screen  360  and a brake sub-system  361  in accordance with another embodiment of the present invention. The brake sub-system  361  may comprise a disc  362  that is coupled to the cylindrical screen  360  and rotates with it and a brake member  363  that interacts with the disc  362  to reduce the rotational velocity of the cylindrical screen  360 . In this embodiment, there is also a spring  364  coupled to the cylindrical screen  360  that biases the disc  362  into contact with the brake member  363 . Thus, in this embodiment as the cylindrical screen  360  rotates, the interaction between the disc  362  and the brake member  363  will: (1) reduce rotational velocity of the cylindrical screen  360 ; and (2) move the cylindrical screen  360  linearly in a direction of its rotational axis. Specifically, as the protuberance on the brake member  363  moves from being located within one of the valleys of the disc  362  to being located along one of the bumps of the disc  362 , this will slow rotation of the cylindrical screen  360  and also cause the cylindrical screen  360  to move to the right. Then, as the protuberance on the brake member  363  moves from being located along one of the bumps of the disc  362  to being located within one of the valleys of the disc  362 , the spring force will cause the cylindrical screen  360  to move back to its original position (i.t., to move to the left). Thus, the components of  FIGS.  18  and  19    can be used to create the linear movement shown in  FIG.  17   . 
     Finally, referring to  FIGS.  20  and  21   , another embodiment of a brake sub-system  370  is illustrated. The brake sub-system  370  comprises a disc  371  and a brake member  372 . In this embodiment, the disc  371  is a ratchet and the brake member  372  is a pawl. The ratchet and pawl configuration of the disc  371  and brake member  372  permits the cylindrical screen to which the disc  371  is attached to rotate in one direction while preventing rotation in the opposite direction. Thus, if the cylindrical screen to which the disc  371  is attached is moved linearly across a skin surface in one direction, the disc  371  and the cylindrical screen will rotate and the pawl will not prevent this rotation. However, if the cylindrical screen to which the disc  371  is attached is moved linearly across the skin surface in the opposite direction, the disc  371  and the cylindrical screen will be prevented from rotating due to the engagement between the pawl and the ratchet. 
     Thus, this embodiment may be beneficial for shaving both upright hairs and flat hairs. Specifically, the apparatus may be moved in a first direction whereby rotation of the cylindrical screen is permitted to cut the upright hairs and then the apparatus may be moved in a second direction opposite to the first direction whereby rotation of the cylindrical screen is prevented to cut the flat hairs. If the skin surface is a user&#39;s face, the shaving apparatus may be moved upwardly to cut upright hairs and then downwardly to cut flat hairs, or vice versa. In this embodiment, users can enjoy shaving with full rolling without irritation and for hard to shave spots can invert the device and shave in a regular mode. 
     Thus, using the inventive techniques described herein, a single shaving apparatus can be used with the screen moving across the skin in a sequence that includes any of two or more of a full skid, a partial skid, and a full roll. In a full roll, the screen is able to freely rotate during use so that there is no relative motion between the screen and the skin (best for cutting hairs that extend perpendicularly from the skin). In a full skid, the screen does not rotate at all, but rather it is dragged across the skin (best for cutting hairs that lay flat on the skin). In a partial skid, the screen may roll, but in such a way that there is some relative motion between the screen and the skin. Thus, in a partial skid, the screen will roll, but will also be dragged across the skin although to a lesser extent than when in a full skid. In other embodiments, particularly  FIGS.  20  and  21   , the disclosure is for a device that, in one direction is in full skid and in the other direction is in full roll or partial roll. 
     As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls. 
     While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. Thus, the spirit and scope of the invention should be construed broadly as set forth in the appended claims.