MXPA01006759A - Surface conforming shaving razor and handle therefor - Google Patents

Abstract

A shaving razor including a handle (12) and three blade units (14, 16, 18) each connected to the handle by a respective amounting structure that provides a pivotal connection of said blade unit to said mounting structure (20) about a pivot axis (60) that is transverse to the cutting edge, and also provides controlled up and down movement of said blade unit thereby permitting each said blade unit to conform to the contour of a surface being shaved. The handle has an index finger indent (24) on a top surface (71), and thumb indent (76) on the bottom surface (72), and is shaped to match the curvature of a user's hand.

Description

SHAVING MACHINE THAT ADAPTS TO SURFACES AND HANDLE FOR THE SAME DESCRIPTION OF THE INVENTION The invention relates to a shaving machine that adapts to the surface being shaved. Shavers typically have straight cutting edges, while surfaces that are shaving have varying degrees of flatness or curvature, and varying deformation capacities to provide a flat surface for the straight edge of the razor. Shaving an area of the body with a pronounced curvature, for example, an ankle or knee, using a razor having a straight cutting edge results in a localized contact area. This requires repeated passes to shave the entire area, and causes a high concentration of tension in the localized contact area, which can increase the possibility of a crack or cut in that area. In one aspect, the invention generally incorporates a razor including a handle, three razor units that are mounted on the end of the handle, and a mounting structure that connects each razor unit to the handle. Each unit of knife includes a guard, at least one knife that has a cutting edge, and a lid. The mounting structure provides a pivot connection of the knife unit to the structure of Ref: 131128 mounted on a pivot axis that is transverse to the cutting edge, and also offers the upward and downward movement of the knife unit along a direction of travel that is transverse to a plane through the guard and cover , thus allowing each razor unit to adapt to the contour of a surface that is being shaved. In one aspect, the invention generally incorporates a razor including a handle and a razor unit which is mounted at the end of the handle by an articulated four-bar and parallelogram mechanism made of a piece of integral plastic including two elongate elements, a proximal end element connected to the handle, and a distal end element connected to the razor unit. The elongate elements and the proximal and distal end elements are pivotally connected to each other by means of elastic live hinges that allow the upward and downward movement of the razor unit. In another aspect, the invention generally incorporates a razor including a handle and three razor units that are mounted at the end of the handle by a mounting structure. The cutting edges of the knives of two of the razor units are generally aligned with each other and have a space between them, and the third knife unit is off center with respect to the other two, with its pocket knife overlapping the space. The aligned razor units have depressed surface portions in respective caps, and the third razor unit is located partially in the region of the depressed surface portions.

Modes of the invention may include one or more of the following characteristics. The mounting structure for each razor unit is independent of the mounting structures for the other razor units, allowing each razor unit to pivot on a respective pivot axis and be moved along a respective displacement axis - independently of the pivoting and displacement of the other units of the knife. The integral plastic part of the four-bar articulated mechanism has a rest position in which the elongated elements are separated from one another and a stop position in which the elongated elements make contact with each other, and the part is elastically deformed live hinges to provide a force resistance movement from a rest position to a stop position, the razor unit moving up and down along the axis of travel as the elongated elements move towards each other and away of others. The mounting structure has a second live hinge that provides pivoting on the pivot shaft, the second living hinge being elastically deformed to provide a force-resistant pivoting on the pivot shaft from a neutral position. The planes through the guards and covers of the razor units are generally coplanar when they are in a rest position with respect to the axis of travel and in a neutral position with respect to the pivot axis. The cutting edges of the knives of the first and second units are generally aligned with each other and have a space between them, and a third unit of knife is off-center with respect to the first and second units of the knife, with its knife overlapping the space during all pivoting positions and up and down movement. The knives of the knife units measure between 0.635 and 1.90 centimeters (1/4"and 3/4") long (preferably between 0.952 and 1.59 centimeters (3/8"and 5/8") in length, and very preferably about 1.27 centimeters (1/2") long.) The razor units are mounted to resist displacement from a rest position with a spring constant of between 5 and 30 (preferably between 10 and 29, and most preferably around of 15) gm force / mm The blade units are mounted to resist pivoting on the pivot axis from the neutral position with a spring constant of between 3 and 20 grams-millimeters / radian.The plastic of the mounting structure is an elastomeric polymer, preferably a polyethylene block amide available under the trade designation PEBAX.The integral plastic part measures between 0.203 to 0.457 millimeters (0.008 to 0.018 inches) thick (preferably 0.305 to 0.355 millimeters (0.012 to 0.014 inch) das)) on the live hinges that provide up and down movement. The integral plastic piece measures between 0.152 to 0.355 millimeters (0.006 to 0.014 inches) thick (preferably 0.228 to 0.279 millimeters (0.009 to 0.011 inches)) in the living hinge that provides the pivoting. The mounting structure can be mounted at an angle with respect to the handle. Each unit of knife has several knives. In other aspects, the invention generally incorporates a razor handle having a shape that is adaptable and allows a variety of different holds to be used. In one aspect, the upper surface of the handle has a depression for elongated index finger that is long enough to support multiple segments of an index finger. In another aspect, the lower surface of the handle has an elongated thumb depression that is sufficiently long along a longitudinal axis to support both segments of a thumb oriented along the longitudinal axis. In another aspect, the upper surface of the handle is sufficiently long and the distal region is curved and shaped to fit in the palm of a user when an index finger is placed in a proximal region of the upper surface. In another aspect, the side surfaces of the handle have a neck region between two wider regions, the neck region being long enough to receive a thumb on one side and a plurality of fingers on the other side. The index finger depression measures approximately 1.59 centimeters (5/8") wide and approximately 5.71 centimeters (21/4") in length, and the depression for the thumb measures approximately 2.54 centimeters (1") wide and approximately 7.62 centimeters (3") long. The thumb depression has a flange at its distal end to indicate the end of the depression to the user. The thumb depression is sunk into an axis that is transverse to the longitudinal axis with a curvature sufficient to receive the end segment of a thumb oriented along the transverse axis. Modes of the invention may include one or more of the following advantages. The razor provides a system of adaptable knives in which the force is evenly distributed over areas of pronounced curvature. There is more razor contact on curved surfaces with the result that shaving is faster and more efficient. Less stress develops with the result that the razor glides smoothly across the surface. The shaver is self-adjustable, making it easy to use. The shaver adapts to pronounced curvatures with the application of low forces on the razor units and conforms to both convex and concave surfaces. The razor maintains a local shaving geometry on the skin (eg, razor angle and exposure), while providing more contact and conforming to the curvature. The total mixed size of the razor unit series is similar in length to any common cartridge. There are no unshaven strips between the individual razor units. The coverage area of the razor units is adapted in narrow areas. The flexing tips bend in a controlled manner. The individual razor units do not interfere with each other. The razor achieves a uniform load distribution between the individual razor units, providing a maximum percentage contact area for each razor unit. The razor has a uniform load distribution through each razor unit. The rigidity of the extremities is selected to maintain contact with the skin to avoid vibration in this way. The four-bar articulated mechanism provides up and down movement, while maintaining the orientation of the plane of the cutting edges of the knives. The razor provides a smooth, safe and comfortable shave. The handle is shaped to fit naturally in the user's hand and receives many grip styles. It has soft grip materials in key places. Other advantages and features of the invention will become apparent from the following description of preferred embodiments thereof and the claims. Figure 1 is a perspective view of a razor. Figure 2 is an elevation of the razor of Figure 1. Figure 3 is a view showing the arrangement, shape and coverage area of the razor units of the razor of Figure 1. Figure 4 is an elevation of a four-bar articulated mechanism mounting structure and razor unit attached to the razor of FIG. 1 in a rest position. Figure 5 is an elevation of the mounting structure and knife unit of Figure 4 in a flexed position of maximum vertical displacement. Figure 6 is a diagrammatic side partial elevation showing the razor units and portions of the mounting structure of the razor of Figure 1 at rest and neutral pivot positions. Figure 7 is a diagrammatic partial elevation showing the razor units of Figure 6 in displaced positions and pivot angles while shaving on a curved surface. Figure 8 is a top view of the handle of the razor of Figure 1.

Figure 9 is a bottom view of the handle of the razor of Figure 1. Figure 10 is a side view of the handle of the razor of Figure 1. Figures 11-15 are perspective views illustrating different manual grip positions when the razor of Figure 1 is used. Referring to Figure 1, there is shown a razor 10 which includes a handle 12 and three razor units 14, 16 and 18 which are connected each one to the handle 12 by a respective mounting structure 20. The handle 12 has a hard plastic area 22 and depression for elongated index finger 24 with an elastomeric surface layer, to be coupled by the index finger or other fingers, depending on which grip is being used. Referring to Figure 2, it is noted that in a rest condition in which the mounting structures 20 are not flexed, the lower surfaces of the razor units 14, 16 and 18 rest in a common plane 26. Each structure of assembly 20 includes a proximal end 28 connected to the handle 12, a distal end 30 connected to the respective knife unit 14, 16 or 18, and elongate elements 32 and 34 connecting the distal end 30 to the proximal end 28. Referring to FIG. Figure 3, it is noted that the follower blade unit 16 has a symmetrical shape, while the front razor units 14 and 18 have depressed portions 36 and extended lid areas 38. each razor unit includes at least two blades 40 and it has elastomeric guard with flaps 42 and lid 44. The knives 40 each measure approximately 1.27 centimeters (one-half inch) long, and the knives in the follower unit 16 overlap the space that exists between the knives of the two front units 14 and 18. The length of the mixed total size of the knife units 14, 16 and 18 is similar in length to that of a common cartridge. Referring to Figure 4, the mounting structure 20 is shown in detail. It is made of an integral molded plastic part of PEBAX, a polyethylene block amide available from Elf Atochem, Birdsboro, PA, or other elastomeric polymer. The mounting structure 20 includes a thinned area 50 for improved molding ability. It also includes connector elements 52 at the distal end 30. The mounting structure 20 has four live hinge sections 54 in which the plastic is gradually tapered to about 0.330 millimeters (0.0130 inches) thick, as shown in Figure 4 This provides a four-bar parallelogram articulated mechanism structure including elongate members 32 and 34, a side member 56 at the distal end 30 and a side member 58 at the proximal end 28. This four-bar parallelogram articulated mechanism provides displacement. controlled so that the razor unit 14 will maintain its orientation shown in Figure 4 while being moved upward (eg, as a result of the increased force on the surface of the knife unit 14) toward the position shown in Figure 5 The knife units do not rotate around axes parallel to the cutting edges during this up and down movement and the mounting structures 20 do not bend or twist, providing only the upward and downward movement of the respective knife unit, with a slight displacement to the sides, as is apparent by comparing the horizontal position of the knife unit 14 in FIG. Figure 4 with its position in Figure 5. Due to this controlled movement, the individual knife units do not interfere with each other and maintain their relative positions, to ensure that the follower unit 16 covers the space between the blades of the front units 14 and 18, and avoid stripes. In Figure 4 the mounting structure 20 is shown in a resting (ie discharged) position. In Figure 5, the mounting structure 20 is shown in a stop position in which the thicker portions of the elongated elements 32 and 34 are joined together, avoiding the additional upward displacement. The living hinges 54 are elastically deformed to provide pivoting and tend to return to the rest position as the displacement force is reduced. Referring to Figures 4 and 6, it is noted that the distal end 30 of each mounting structure 20 has a living hinge 62 on the respective knife unit 14, 16 and 18 to provide the running of the individual knife units around the respective pivot shafts 60. In Figure 6, the razor units 14, 16 and 18, mounting structures 20 and live hinges 62 are shown in neutral rest positions such as would be achieved when they were not pressed against a surface or when pressed uniformly against a surface. flat surface. Live hinges 62 are elastic, and will return elastically to this position. The corners 69 act as detents, preventing further rotation by interacting with the upper surfaces of respective cartridges. In Figure 7, the razor units are shown in positions and away orientations resulting from shaving on the curved surface 70. On the surface 70, the mounting structure 20 for the follower knife unit 16 has been moved up slightly with with respect to the other mounting structures 20, and the razor unit 18 has pivoted leftwardly in its living hinge 62, while the razor unit 14 has pivoted clockwise in its living hinge 62. Each unit of knife 14, 16 and 18 is then capable of independent movement both in a direction of upward and downward movement and in pivoting to distribute the contact forces against the surface being shaved and to follow and adapt to the curvature of the surface being shaved. In this way, lower stresses on the cutting edges result. The combination of live hinges 54 and live hinges 62 then allows the razor units 14, 16 and 18 to roll and move up and down without tilting or sloping. The handle 12 coincides with the natural curvature at rest of human hands, including the curvature in the transverse arch of the base of the palm, the curvature of the transverse arch at the distal end of the palm in the fingers, and the curvature of the arch longitudinal that extends from the base of the palm to the ends of the fingers. The resting position of the hand is considered to be the most suitable to do the job, and the position of less hand tension gives the user the feeling of greater control and comfort.

In addition, the handle 12 is provided with depressions and neck regions to allow comfortable grip in a variety of grip positions, as shown in Figures 11-15. Referring to Figures 3-10, the handle 12 has an upper surface 71, lower surface 72, side surfaces 73 and end 74 for its connection to the knife units 14, 16 and 18. The depression for index finger 24 on the Top surface 70 measures approximately 1.59 centimeters (5/8") wide and approximately 5.71 centimeters (21 / 4u) long, and is long enough to support at least two segments of an index finger, providing a greater degree of The upper surface 71 also has a curved proximal region (with respect to the user's hand) 78. The upper surface 71 is sufficiently long and the proximal region 78 is configured so that the proximal region 78 fits the palm of the palm. a user when an index finger is placed on the depression for index finger 24, this also provides a more comfortable feel and proper control.The lower surface 72 has a depression for thumb-wing rgada 76 that is approximately 2.54 centimeters (1") wide and approximately 7.62 centimeters (3") long, which is long enough along a longitudinal axis to support both segments of a thumb when it is oriented to along the longitudinal axis. The thumb depression 76 has a flange 82 at its distal end to indicate the end of the depression to the user. The thumb depression 76 is sunk into an axis that is transverse to the longitudinal axis with a curvature sufficient to receive the end segment of a thumb oriented along the transverse axis. The surfaces 73 converge to provide a neck region 80 between two wider regions. The neck region 80 is long enough and is configured to receive a thumb on one side and a plurality of fingers on the other side. Referring to Figures 11-15, the handle receives different grip positions that can be used by different users when shaving different parts of the body, such as the legs, arms, armpits and bikini area. A first grip position (Figure 11) includes the thumb on the back of the thumb grip, and several fingers wrapped on the top surface of the handle. A second grasping position (Figure 12) involves holding the distal end of the handle in the palm, with the V between the thumb and the index finger being located on the upper surface 71. A third grasping position (Figure 13), called the Extrusion involves placing the thumb on the depression for thumb 76 transverse to its longitudinal axis, and the other fingers extending above and transverse to the depression for index finger 24. A fourth grasping position (Figure 14) involves placing the index finger on the thumb. length of the depression for index finger 24, the thumb in the neck region 80 and the remaining fingers wrapped around the proximal portion 78. A fifth grasping position (FIG. 15) involves placing the thumb on and transverse to the depression for thumb 76 on its back, and receiving the curved proximal portion 78 of the handle on the side of a crooked index finger. During shaving, the shaver is self-adjusting and adapts to both convex surfaces (for example, knees and ankles) and concave surfaces (for example, armpit). The individual razor units 14, 16 and 18 maintain a local shaving geometry on the skin (eg, razor angle and exposure) while adjusting independently to the curvature. Only small forces are required to cause upward displacement, so there is a relatively uniform load distribution between the individual razor units. The individual knife units 14, 16 and 18 have a uniform load distribution through their knives. Other embodiments of the invention are within the scope of the claims. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (57)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A razor characterized in that it comprises: a handle, first, second and third razor units that are mounted on the end of said handle, each one of said knife units includes a guard, at least one knife having a cutting edge, and a cover, and a mounting structure connecting each of said knife units to said handle, the mounting structure provides a connection pivotal of said razor unit to said mounting structure on a pivot axis that is transverse to the cutting edge, and also provides up and down movement of said razor unit along a direction of travel that is transverse to a plane a through the guard and cover, thus allowing each razor unit to adapt to the contour of a surface being shaved. The razor according to claim 1, characterized in that said mounting structure for each of said razor units is independent of the mounting structures for the other razor units, allowing each razor unit to pivot on a respective pivot axis and is displaced along a respective displacement axis independently of the pivoting and displacement of the other knife units. The razor according to claim 2, characterized in that each of said mounting structures includes an articulated mechanism with two elongated elements extending from a proximal end element connected to said handle to a connected distal end element. to said razor unit. The razor according to claim 3, characterized in that said articulated mechanism forms a paraielogram which includes said two elongated elements and also includes a first lateral element connected between proximal ends spaced apart from said elongated elements and said proximal end element , and a second lateral element connected between distal ends spaced apart from said elongated elements and said distal end element, said elongated elements being pivotally connected at each connection to the first lateral element and to the second lateral element. The razor according to claim 4, characterized in that said articulated mechanism is formed of an integral plastic part and includes first live hinges in said connections of the elongated elements to said first and second lateral elements. 6. The razor according to claim 5, characterized in that said integral plastic part has a rest position in which the elongated elements are separated from each other, and a stop position in which the elongated elements make contact with each other. others, said piece being elastically deformed in said live hinges to provide a force-resistant movement from said rest position to said stop position, the knife unit moves up and down along said direction of travel when moving the elongated elements towards and away from each other. The razor according to claim 5 or 6, characterized in that the mounting structure includes a second live hinge that provides said pivoting on said pivot axis, the second living hinge being elastically deformed to provide a force-resistant pivoting. on said pivot axis from a neutral position. The razor according to claim 5 or 6, characterized in that said mounting structure includes a second living hinge that provides said pivoting on said pivot axis, the second living hinge being elastically deformed to provide a force-resistant pivoting. on said pivot axis from a neutral position, said mounting structure including a retainer structure which limits the pivoting on said pivot axis. 9. The razor according to claim 1, characterized in that said planes through said guards and covers of said razor units are generally coplanar when they are in a rest position with respect to said displacement axis and in a neutral position with respect to said axis of displacement. with respect to said pivot axis. The razor according to claim 8, characterized in that said planes through said guards and covers of said razor units are generally coplanar when said elongated elements are in said rest positions and said second live hinges are in their positions. neutral positions. The razor according to claim 1, characterized in that the cutting edges of the knives of said first and second units are generally aligned with each other and have a space between them, and a third knife unit is off center with respect to to said first and second knife units, with its blade overlapping said space during all the positions of said pivoting and up and down movement. The razor according to claim 1, characterized in that said third razor unit is located behind said first and second razor units. The razor according to claim 10, characterized in that the cutting edges of the knives of said first and second units are generally aligned with each other and have a space between them, and a third knife unit is off center with respect to to the other two, with his pocket knife overlapping this space. The razor according to claim 10, characterized in that said third razor unit is located behind said first and second razor units. 15. The razor according to claim 1, characterized in that said knives of said razor units measure between 0.635 and 1.90 centimeters (1/4"and 3/4") long. 16. The razor according to claim 1, characterized in that said knives of said razor units measure about 1.27 centimeters (1/2") in length 17. The razor according to claim 9, characterized because said razor units are mounted to resist said displacement from said rest position with a spring constant of between 5 and 30 gm force / mm 18. The razor according to claim 9, characterized in that said razor units are mounted to resist said movement from said rest position with a spring constant of between 10 and 20 gm force / mm 19. The razor according to claim 9, characterized in that said knife units are mounted to resist said pivoting on said pivot axis from said neutral position with a spring constant of between 3 and 2 grams-millimeters / radian. 20. The razor according to claim 6, characterized in that said plastic is an elastomeric polymer. 21. The razor according to claim 20, characterized in that said plastic is a polyethylene block amide. 22. The razor according to claim 20, characterized in that said plastic is PEBAX. 23. The razor according to claim 6, characterized in that said integral piece of plastic measures between 0.203 to 0.457 millimeters (0.008 to 0.018 inches) in thickness in said first live hinges. The razor according to claim 6, characterized in that said integral piece of plastic measures between 0.305 to 0.355 millimeters (0.012 to 0.014 inches) in thickness in said first live hinges. 25. The razor according to claim 7, characterized in that said integral piece of plastic measures between 0.152 to 0.355 millimeters (0.006 to 0.014 inches) in thickness in said second live hinges. 26. The razor according to claim 7, characterized in that said integral piece of plastic measures between 0.228 to 0.279 millimeters (0.009 to 0.01 1 inch) in thickness in said second live hinges. 27. The razor according to claim 1, characterized in that said mounting structure also provides pivoting on an axis parallel to the cutting edge. The razor according to claim 1, characterized in that said handle is elongated along a longitudinal axis, And said mounting structures are oriented in a rest position at an angle with said longitudinal axis. 29. The razor according to claim 1, characterized in that each of said razor units has several knives. 30. The razor according to claim 1, characterized in that each of said razor units has movable knives. 31. A razor characterized in that it comprises: a handle, a razor unit that is mounted on the end of said handle, and includes a guard, at least one knife has a cutting edge, and a cover, and an articulated mechanism of four bars and parallelogram connecting said knife unit to said handle, said articulated mechanism being made of an integral plastic piece and includes two elongated elements, a proximal end element connected to said handle, and a distal end element connected to said handle. said razor unit, each of said elongate elements being pivotally connected by means of first elastic live hinges at respective ends to said proximal end element and said distal end element, said first live hinge provides the upward and downward movement of said unit of a knife along a displacement axis that is transversal to a plane through the guard and cover. The razor according to claim 31, characterized in that said integral plastic part has a rest position in which said elongated elements are separated from each other and a stop position in which said elongated elements make contact between yes, said piece is elastically deformed in said first live hinges to provide a force resistance movement from said rest position to said stop position, the razor unit moving up and down along said direction of travel to moving said elongated elements towards each other and away from each other. The razor according to claim 31, characterized in that said articulated mechanism includes a second live hinge that provides pivoting on a pivot axis that is perpendicular to the cutting edge, said second hinge being elastically deformed to provide a sturdy pivot. to forces on said pivot axis from a neutral position, said articulated mechanism includes a retainer structure which limits the pivoting on said pivot axis. 34. A razor characterized in that it comprises: a handle, first, second and third razor units that are mounted at the end of said handle, each of said razor units includes a guard, at least one knife that has a cutting edge, and a cover, a mounting structure connecting each of said knife units to said handle, the cutting edges of the knives of said first and second knife units being generally aligned with each other and having a space between them said third razor unit being off center with respect to the other two, with its blade overlapping said space, said first and second razor units having portions of depressed surface in respective caps, said third razor unit being located partially in the region of said depressed surface portions. 35. The razor according to claim 34, characterized in that said knives of said razor units measure between 0.952 and 1.59 centimeters (3/8"and 5/8") long. 36. The razor according to claim 34, characterized in that said knives of said razor units measure about 1.27 centimeters (1/2") long. 37. A razor handle characterized in that it comprises: an elongated hand grip structure having a top surface and a bottom surface and an end for connection to a razor unit oriented with the cutting edges directed away from said top surface, said surface upper has a depression for elongated index finger that is long enough to support multiple segments of an index finger. 38. A razor handle characterized in that it comprises: an elongated hand grip structure having a top surface and a bottom surface and an end for connection to a razor unit oriented with the cutting edges directed away from said top surface, said upper surface has a depression for elongated thumb which is sufficiently long along a longitudinal axis to support both segments of a thumb oriented along said longitudinal axis. 39. A razor handle characterized in that it comprises: an elongated hand grip structure having a top surface and a bottom surface and an end for connection to a razor unit oriented with the cutting edges directed away from said top surface, said upper surface has a first finger depression and said lower surface has a second finger depression. 40. A razor handle characterized in that it comprises: an elongated hand grip structure having a top surface and a bottom surface and an end for connection to a razor unit oriented with the cutting edges directed away from said top surface, said upper surface has a distal region near said end to receive an index finger and a curved proximal region, said upper surface being sufficiently long and said distal region being configured to fit in the palm of a user when an index finger is placed on it. said proximal region. 41. A razor handle characterized in that it comprises: an elongated hand grip structure having a top surface and a bottom surface and an end for connection to a razor unit oriented with the cutting edges directed away from said top surface, said elongated manual grip structure also has lateral surfaces between said upper surface and said lower surface, said lateral surfaces having a neck region between said two wider regions, said neck region being long enough to receive a thumb on one side and a plurality of fingers on the other side. 42. The handle according to claim 39, characterized in that said first finger depression is a depression for elongated index finger that is long enough to support multiple segments of an index finger, and said second finger depression is a depression for elongated thumb that is long enough along a longitudinal axis to support both segments of a thumb oriented along said longitudinal axis. 43. The handle according to claim 40, characterized in that said distal region has a depression for elongated index finger that is long enough to support multiple segments of an index finger. 44. The handle according to claim 40, characterized in that said lower surface has an elongated thumb depression that is sufficiently long along a longitudinal axis to support both segments of a thumb oriented along said longitudinal axis . 45. The handle according to claim 40, characterized in that said distal region has a depression for elongated index finger that is long enough to support multiple segments of an index finger., and said lower surface has an elongated thumb depression that is sufficiently long along a longitudinal axis to support both segments of a thumb oriented along said longitudinal axis. 46. The handle according to claim 41, characterized in that said upper surface has a depression for elongated index finger that is long enough to support multiple segments of an index • finger. 47. The handle according to claim 41, characterized in that said lower surface has an elongated thumb depression that is sufficiently long along a longitudinal axis to support both segments of a thumb oriented along said longitudinal axis . 48. The handle according to claim 41, characterized in that said upper surface has a depression for elongated index finger that is long enough to support multiple segments of an index finger, and said lower surface has a depression for elongated thumb which is sufficiently long along a longitudinal axis to support both segments of a thumb oriented along said longitudinal axis. 49. The handle according to claim 37, 42, 43 or 47, characterized in that said index finger depression measures approximately 1.59 centimeters (5/8") in width and approximately 5.71 centimeters (21M") in length 50. The handle according to claim 38, 42, 44 or 48, characterized in that said depression for the thumb is approximately 2.54 centimeters (1") wide and approximately 7.62 centimeters (3") long. 51. The handle according to claim 38, 42, 44 or 48, characterized in that said thumb depression has a rim at its distal end to indicate the end of the depression to the user. 52. The handle according to claim 38, 42, 44 or 48, characterized in that said depression for the thumb is sunk into an axis that is transverse to said longitudinal axis with a curvature sufficient to receive the end segment of a thumb oriented along said transverse axis. 53. The razor according to claim 1, 31 or 34, characterized in that said handle comprises: an elongated manual grip structure having an upper surface and a lower surface and an end for its connection to a razor unit oriented with cutting edges directed away from said top surface, said top surface has a depression for elongate index finger that is long enough to support multiple segments of an index finger. The razor according to claim 1, 31 or 34, characterized in that said handle comprises: an elongated manual grip structure having a top surface and a bottom surface and an end for its connection to a razor unit oriented with the cutting edges directed away from said upper surface, said lower surface has a depression for elongated thumb which is sufficiently long along a longitudinal axis to support both segments of a thumb oriented along said longitudinal axis. 55. The razor according to claim 1, 31 or 34, characterized in that said handle comprises: an elongated manual grip structure having an upper surface and a lower surface and an end for its connection to a razor unit oriented with cutting edges directed away from said top surface, said top surface has a first finger depression and said bottom surface has a second finger depression. 56. The razor according to claim 1, 31 or 34, characterized in that said handle comprises: an elongated manual grip structure having an upper surface and a lower surface and an end for its connection to a razor unit oriented with cutting edges directed away from said top surfacesaid upper surface has a distal region near said end to receive an index finger and a curved proximal region, said upper surface being sufficiently long and said distal region being configured to fit in the palm of a user when an index finger is placed in said proximal region. 57. The razor according to claim 1, 31 or 34, characterized in that said handle comprises: an elongated manual grip structure having a top surface and a bottom surface and an end for its connection to a razor unit oriented with the cutting edges directed away from said upper surface, said elongated manual grip structure also has lateral surfaces between said upper surface and said lower surface, said lateral surfaces having a neck region between said two wider regions, said neck region being long enough to • receive a thumb on one side and a plurality of fingers on the other side. THE SAME SUMMARY OF THE INVENTION A razor is described which includes a handle (12) and three knife units (14, 16 and 18) each connected to the handle by a respective mounting structure which provides a pivotal connection of said knife unit to said structure. assembly (20) on a pivot shaft (60) that is transverse to the cutting edge, and also provides the controlled upward and downward movement of said knife unit, thus allowing each of said knife units to adapt to the contour of a surface that is shaving. The handle has a depression for index finger (24) on an upper surface (71), and a depression for thumb (76) on the lower surface (72), and is configured to coincide with the curvature of a user's hand .