Disclosure of Invention
In view of the above, the present invention provides a dry shaver capable of close shaving in a narrow area as in other areas. The dry shaver according to the present invention includes a shaving head that is elongated to have a longitudinal axis and is configured to carry a semi-cylindrical first outer blade, a semi-cylindrical second outer blade, a semi-cylindrical finishing blade, and a slit blade, which are each elongated along the longitudinal axis and are disposed substantially parallel to each other. The semi-cylindrical first and second outer blades each include a main blade net having a plurality of cells, and an inner blade driven by a motor to move in sliding contact with the main blade net. The main foil is curved arcuately into an arcuate profile about an axis parallel to the longitudinal axis. The slit blade includes an elongated outer blade having a plurality of slits open at its lateral edges and an inner blade driven to move in sliding contact with the outer blade. The semi-cylindrical finishing blade includes a finishing foil with a plurality of holes and an inner blade driven by a motor to move in sliding contact with the finishing foil. The finishing foil is also arcuately curved about an axis parallel to the longitudinal axis into an arcuate profile. The present invention is characterized in that semi-cylindrical first and second outer blades are disposed at opposite lateral ends of a shaving head, and semi-cylindrical finishing blades and slit blades are disposed between the semi-cylindrical first and second outer blades, and a finishing foil is formed to have a width smaller than that of a main foil or to have a thin portion reduced in thickness relative to the main foil at least around a portion of each perforation. With such an arrangement in which the semi-cylindrical first outer blade, the semi-cylindrical finishing blade, the slit blade, and the semi-cylindrical second outer blade are disposed in this order along the transverse axis of the shaving head, the semi-cylindrical finishing blade having a reduced width can be easily and effectively brought into contact with narrow areas, for example, under the nose, the tip of the chin, and under the chin, to more effectively perform close hair shaving than the semi-cylindrical first outer blade or the second outer blade. Further, since the finishing blade is disposed between the first outer blade and the slit blade, the finishing blade can be prevented from pressing too hard against the skin, and thus can shave closely without irritating the skin or causing accompanying pain.
Preferably, the finishing foil is shaped to have a smaller width than the main foil and a thin portion around at least a portion of each perforation to improve close shaving.
The finishing foil may be configured to have a region in which each of the perforations is partially surrounded by a thin portion and partially surrounded by a thick portion. The thin portion provides more opportunity to introduce hairs deep into the associated perforations for a more effective close shave.
Preferably, the shaving head comprises a frame configured to floatingly support the main foil and the finishing foil. In this case, the main blade net and the finishing blade net are spring-biased to be in pressure contact with the skin of the user, and the main blade net of the second outer blade is spring-biased more than the main blade nets of the finishing blade net and the first outer blade. Thus, when the shaving head is moved across the skin with the first outer blade located on the front side in the moving direction, the second outer blade located on the rear side with respect to the moving direction can be moved along the skin while being held pressed against the skin with sufficient pressure, thus tightening the skin to perform close shaving also at the second outer blade.
The finishing foil may be coupled to the main foil of the semi-cylindrical first outer blade by an adjustment spring so as to be pressed from the main foil of the first outer blade in a direction against the skin of the user. The adjustment spring generates a spring reaction force acting on the first outer blade to reduce the spring bias assigned to the first outer blade itself while increasing the spring bias assigned to the finishing net itself, thus achieving appropriate assignment of the spring bias to the first outer blade and the cylindrical finishing blade, respectively, for effective shaving with a combination of these blades.
Further, the outer blade of the slit blade may be floatingly supported on the frame and coupled to the finishing foil by another adjusting spring so as to be pressed from the finishing foil in a direction against the skin of the user. In this case, the adjustment spring generates a spring reaction force acting on the finishing blade to reduce the spring bias assigned to the finishing blade itself, thus achieving appropriate assignment of the spring bias to the finishing circular blade and the slit blade, respectively.
Further, the first outer blade is preferably disposed such that the tip end thereof is lower than the tip end of the second outer blade. With this arrangement, the first and second outer blades can be kept in simultaneous contact with curved or inclined areas of the skin, for example, under the chin, for effective shaving on these areas by the combination of the blades.
These and other advantageous features of the present invention will become more apparent from the following detailed description of the preferred embodiments when taken in conjunction with the accompanying drawings.
Detailed Description
Referring now to fig. 1-5, a dry shaver according to a preferred embodiment of the present invention is shown. The dry shaver includes a handle 60 and a shaving head 100 mounted to the top of the handle 60. An elongated shaving head 100 having a longitudinal axis and a transverse axis is movably connected to the handle 60 relative to the handle 60 about an axis perpendicular to the longitudinal axis. The shaving head 100 carries four differently configured blades, namely a semi-cylindrical first outer blade 10, a semi-cylindrical second outer blade 20, a semi-cylindrical finishing blade 30 and a slit blade 40. The blades are elongated along the longitudinal axis of the shaving head 100 and are arranged parallel to each other along the transverse axis.
The shaving head 100 includes a housing 120 and a holder 130 separable from the housing 120. The housing 120 is a waterproof structure in which the linear motor 150 is accommodated and is configured with a plurality of driving elements 210, 220, 230, and 240 protruding at the top of the housing 120 as shown in fig. 5. These drive elements are connected to the linear motor 150 to be driven thereby to reciprocate along the longitudinal axis of the shaving head 100. The first and second outer blades 10 and 20 are disposed at opposite lateral ends of the shaving head 100 with the finishing blade 30 and the slit blade 40 disposed therebetween. The handle 60 is provided with a trimmer 80 at the lateral end of the rear further from the first blade 10 than the second blade 20.
The first outer blade 10 and the second outer blade 20 each include a main blade net 11 and 21, and inner blades 16 and 26, and the inner blades 16 and 26 are driven by a linear motor 150 to reciprocate in hair-cutting engagement with the main blade nets. The main blade net is formed with a plurality of holes and is arcuately bent about an axis parallel to the longitudinal axis of the shaving head 100 into an arcuate contour, i.e., a semi-cylindrical shape having a certain width with respect to the transverse axis of the shaving head. The first outer blade 10 and the second outer blade 20 are configured to have main blades of the same configuration (i.e., the same width and the same radius of curvature) and inner blades of the same configuration. As best shown in fig. 4, the main foil 11(21) is fixed at its opposite transverse ends to mounting brackets 13(23), while the associated inner blade 16(26) is fixed to the base 17 (27). The mount 13(23) is floatingly supported to the frame 130 to be movable relative to the frame, and thus movable relative to the housing 120. The base portions 17 and 27 are formed at their bottoms with catches 18 and 28, respectively, which detachably receive driving elements 210 and 220 for reciprocating the inner blades 16 and 26. Each drive element 210 and 220 carries a biasing spring 212 and 222 which provides a spring bias SB212(SB2222) urging the inner blade and associated primary foil upwardly so that the first outer blade 10 and second outer blade 20 can be depressed when pressed against the skin of a user. The mounting brackets 13 and 23 are fixed to a front cover 111 and a rear cover 112 constituting front and rear walls of the shaving head 100, respectively. The front cover 111 is provided at its longitudinal ends with protruding pieces 19, the protruding pieces 19 being slidably engaged into corresponding vertical grooves 131 of the rack 130. Likewise, the rear cover 112 is provided, at its longitudinal ends, with protruding elements 29, the protruding elements 29 being slidably engaged in corresponding vertical slots 132 of the rack 130.
Finishing blade 30 is provided in shaving head 110 for making a closer shave than first blade 10 and second blade 20, and comprises a finishing foil 31 and an inner blade 36, inner blade 36 being detachably connected to reciprocating drive element 230 for being driven by it in reciprocating motion in hair-cutting engagement with finishing foil 31. The finishing foil 31 is formed with a plurality of perforations 32 and is arcuately bent about an axis parallel to the longitudinal axis of the shaving head 100 into an arcuate contour, i.e., a semi-cylindrical shape having a width along the transverse axis of the shaving head. As best shown in fig. 3 and 6, the finishing foil 31 is deeply curved such that its radius of curvature is smaller than the main foils 11 and 21, and thus the width W3 is smaller than the widths W1 and W2 of the main foils, thereby increasing the chance of catching hairs deep into the perforations, particularly around the top of the finishing foil 31, to cut shorter hairs, i.e., to finish the hairs to a minimum length, than the first and second blades 10 and 20 can reach. As shown in fig. 4, finishing foil 31 is secured at its opposite lateral ends to mounting frame 33, while inner blade 36 is secured to base 37. The base 37 is formed at its bottom with a catch 38 which detachably receives a drive element 230 for reciprocating the inner blade 36. The mounting bracket 33 is floatingly supported to the bracket 130 so as to be movable relative to the housing 120 of the shaving head 100. The mounting bracket 33 is formed integrally with the skin guard 50, which protrudes between the first outer blade 10 and the finishing blade 30 and can move together with the finishing foil 31 relative to the housing 120. The skin guard 50 extends parallel to and closely adjacent to the side edges of the finishing foil 31. The mounting bracket 33 is formed at opposite longitudinal ends thereof with side covers 113, the side covers 113 constituting a part of the side walls of the shaving head 100. The drive element 230 carries a spring 232 which gives a spring bias SB232 which forces the inner blade against the finishing foil 31 and thus forces the finishing blade 31 upwards, so that the finishing blade 31 can be depressed when pressed against the skin of a user. The mounting bracket 33 is also formed at its longitudinally opposite ends with protruding members 39, the protruding members 39 being slidably retained in corresponding slots 133 of the bracket 130 so as to be movable relative to the bracket 130 when the finishing blade 30 is biased upwardly by springs 232.
The slit blade 40 includes an elongated outer blade 41 having a plurality of slits opening to the lateral edges thereof, and an inner blade 46 driven to reciprocate in hair-cutting engagement with the outer blade 41. The outer blade 41 is formed to have a substantially flat top surface so as to be in sliding contact with the skin of the user to catch the flattened hairs into the slits to cut the hairs. The outer blade 41 is fixed to the mounting frame 43, and the mounting frame 43 is floatingly supported on the frame 130. The inner blade 46 is fixed to a base 47, and the base 47 is slidably held on the mounting frame 43 to reciprocate the inner blade 46 relative to the outer blade 41. A spring 44 is provided between the mounting bracket 43 and the base 47 to hold the inner blade 46 against the outer blade 41. The holder 43 is formed at opposite longitudinal ends thereof with protruding pieces 49, and the protruding pieces 49 are slidably engaged into the corresponding grooves 134 of the holder 130 to floatingly support the slit blade 40 to the holder 130. The base 47 forms a catch 48 at its bottom, which detachably receives a drive element 240 for reciprocating the inner blade 46. As shown in fig. 5, the driving element 240 is formed integrally with the driving element 220 but does not bias the slit blade 40. Conversely, a spring 45 is disposed between the shelf 43 and the extension 34 extending from the mounting shelf 33 of the finishing blade 30 to provide a spring bias SB45 urging the slit blade 40 upward.
Fig. 6 shows the height relationship of the four blades in a free state that are not depressed or held in pressing contact with the user's skin. The second blade 20 and the finishing blade 30 are disposed such that their tops are at the same height, while the top of the first blade 10 is lower than the top of the finishing blade 30 by a large difference D1, and the top of the slit blade 40 is lower than the top of the finishing blade 30 by a small difference D4. The top of the skin guard 50, which is movable together with the finishing blade 30, is set higher than the top of the first blade 10, but lower than the top of the finishing blade 30 by a difference D5. With such a multi-blade arrangement, each blade is able to maintain optimal contact with the user's skin for effective shaving. For example, as shown in fig. 8, when shaving hairs under the chin, when the first blade 10 is located on the leading side in the moving direction, the blades simultaneously remain in contact with the skin, so that each shaving is effective. On the other hand, as shown in fig. 9, when shaving a narrow area such as the chin top, the finishing blade 30 may be pressed against the skin in combination with the skin guard 50 and the slit blade 40, thereby cutting the hairs to the shortest. It should be noted in this connection that due to the deep bend, the effective cutting area of the finishing foil 30 is only located around its tip and leaves ineffective areas on its opposite sides, respectively, which areas, when pressed hard against the skin, are liable to cause skin irritation. That is, as shown in fig. 7(a) and 7(B), since the foil F is bent more deeply, so that the foil is pressed against the skin S at its leading side with respect to the moving direction of the shaving head with larger contact angles (α 1, α 2) and thus with larger force, it eventually increases the chance of capturing the skin deeply sunk in the foil eyelet and thus irritates the skin. In this sense, in the case when the shaving head is moved over the skin while the finishing blade is pressed against the skin at its leading side, the deeply curved lower side portions of the finishing blade 30 are not suitable for comfortable shaving, while the upper side portions of the finishing blade are effective for cutting the hairs to the shortest.
In order to prevent the skin from contacting the lower side of the finishing blade, i.e., the inactive area, the skin guard 50 is provided to cover the inactive area immediately adjacent thereto while the top of the skin guard is slightly lower than the top of the finishing blade 30 to expose the active area, i.e., the upper portion around the top of the finishing blade 30, for close shaving. In this regard, the skin guard 50 is biased toward the finishing blade 30 so as not to interfere with the shaving operation of the first outer blade 10. When the shaving head 100 is moved while the second outer blade 20 is positioned at the leading side in the moving direction, the slit blade 40 also functions as another skin guard in a manner of preventing the skin from contacting the lower portion of the finishing blade 30 and minimizing skin irritation.
Returning to fig. 6, the finishing foil 31 is also urged upwardly by an adjusting spring 35, the adjusting spring 35 being interposed between the shelf 33 of the finishing foil 31 and the projection 14 extending from the shelf 13 of the first outer blade 10, so that the finishing foil 31 is subjected to an upward spring bias which is a combination of an upward spring bias SB232 from the spring 232 of the driving element 230, and another upward spring bias SB35 from the adjusting spring 35, and a downward spring bias CF45 which is a counter force to the spring 45 urging the slit blade 40 upwardly. The adjustment spring 35 generates a counter force CF35 which counter force CF35 urges the main foil 11 of the first outer blade 10 downwards so that the first outer blade 10 is subjected to an upward spring bias which is a combination of the upward spring bias SB212 from the spring 212 of the drive element 210 and the downward bias CF35 of the adjustment spring 35. Thus, by using the adjustment springs 35 and 45, an optimum spring bias is assigned to each blade, as schematically shown by the corresponding arrows in fig. 6. In particular, although drive elements 210 and 220 having the same configuration are used, i.e. the spring forces of springs 212 and 222 are the same, different spring biases can be assigned to the first outer blade 10 and the second outer blade 20. For example, when the spring biases SB212, SB232, and SB222 of the drive elements 210, 230, and 220 are selected to be 1.2N, 1.0N, and 1.2N, respectively, in combination with the adjustment spring 35 having a spring force of 0.5N and the spring 45 having a spring force of 0.8N, the first outer blade 10, the finishing blade 30, the slit blade 40, and the second outer blade 20 are assigned spring biases of 0.7N (═ 1.2N-0.5N), 0.7N (═ 1.0N +0.5N-0.8N), 0.8N, and 1.2N, respectively.
Referring to fig. 10 and 11, the structural features of the finishing foil 31 will now be explained in detail. The perforations 32 are arranged in an array comprising rows aligned along the length of the foil and columns aligned along a direction slightly inclined with respect to the width of the foil. As shown in FIG. 11, the foil 30 is formed on its top surface with a plurality of recesses disposed along each row in alternating relation to the perforations 32 to define a plurality of series of thin portions of reduced thickness, with the remainder remaining as thick portions 132 that extend continuously across the entire width of the foil 30 between adjacent rows of perforations 32. Thus, the perimeter of each aperture is defined in part by the thin portion and in part by the thick portion 132. Since the thin portions alternate with the perforations 32 in the column direction, when the shaving head 100 is moved across the skin with the blades oriented with their width generally perpendicular to the direction of movement, the hairs are guided along a series of thin portions, while the flattened hairs can be easily guided into the perforations through the thin portions and are raised at the edges of the perforations 32 adjacent to the thin portions 32 to successfully cut the flattened hairs. On the other hand, the thick portions 132 are provided with flat surfaces extending continuously in the row or foil 31 width direction to provide smooth skin contact for shaving, while retaining the effect of raising and cutting flat hairs by providing the thin portions. For example, the thickness of the thick portion is selected to be 50 μm to 80 μm, and the thickness of the thin portion is 45 μm or less. In this regard, each of the main foils 11 and 12 is made of a foil of a uniform thickness that is greater than the thickness of the thin portion and equal to or greater than the thickness of the thick portion 132.
As shown in fig. 11, each of the eyelets 32 is formed as a hexagon having one pair of opposing long sides and two pairs of opposing short sides. The thin portion is incorporated into the long side and the thick portion 132 is incorporated into the short side. That is, each eyelet 32 is surrounded at its long sides by thin portions and at its short sides by thick portions 132. The top surface of the thin portion is connected to the top surface of the thick portion 132 by an inclined shoulder 131. The hexagons are dimensioned, for example with a length of 0.5mm in the direction of the rows and a width of 0.3mm in the direction of the columns.
As shown in fig. 12 and 13, each eyelet 32 is surrounded by a raised rim 134 projecting at the bottom of the foil 31 and formed with beveled edges 135 and 136 leading from the long and short sides, respectively. The inclined edge 135 extends continuously from the thin portion, and a cutting angle β 1 at a lower end thereof is smaller than a cutting angle β 2 of the inclined edge 136 at the lower end thereof. It was found that a smaller cutting angle β 1 is advantageous for promoting the uprising effect of flat hairs guided by the thin portion. Further, the finishing foil 31 is configured such that the thick portions 132 occupy a larger area than the thin portions, thereby providing sufficient mechanical strength and ensuring smooth skin contact.
Although the above-described embodiment illustrates that the finishing foil 30 includes the thin portion and the thick portion, it is also possible that the finishing foil 30 has no thick portion and has a uniform thickness smaller than that of the main foil. Further, if the width of the finishing foil 31 is smaller than that of the main foil, the main foils 11 and 21 of the first and second outer blades 10 and 20 may be selected to have a similar configuration including a thin portion and a thick portion. The present invention thus includes a structure in which the finishing foil 31 is formed to have a width smaller than that of the main foil and/or the finishing foil 31 includes a thin portion having a thickness smaller than that of the main foil around each of the holes.
In the illustrated embodiment, each of the blades 10, 20, 30 and 40 and the skin guard 50 are slightly arcuately curved with respect to the longitudinal axis to smoothly contact the skin. However, the invention should not be construed as being limited thereto, but may equally comprise configuring at least one of the blade and the skin protection device to have a top surface that is straight with respect to the longitudinal direction.