RAZOR HEAD

Abstract

A razor head includes a frame, elongated blades arranged on an inner side of the frame, and two bridge walls each extending between two points of the frame in an interior of the frame, the bridge walls each including projections arranged in an arrangement direction of the blades. Each of the blades is held between adjacent ones of the projections of the bridge walls. Each of the projections includes a first flat surface and a second flat surface. In each of the bridge walls, the first flat surface and the second flat surface are shifted from each other in a longitudinal direction of the blades so as not to overlap each other, and the first flat surfaces and the second flat surfaces are located on the same position as viewed in the arrangement direction. Each of the projections has a horizontal cross-sectional shape of a parallelogram.

Description

TECHNICAL FIELD

The present disclosure relates to a razor head.

BACKGROUND ART

Patent Literature 1 discloses a razor head.

FIG. 10 shows a typical razor head 60. The razor head 60 includes a frame 61 with a rectangular outer form, three bridge walls 62 each extending between two points of the frame 61 in the interior of the frame 61, and elongated blades (not shown) coupled to the bridge walls 62. Each bridge wall 62 includes pegs 64 (projections). Each blade is held between adjacent ones of the pegs 64.

CITATION LIST

Patent Literature

Patent Literature 1: Japanese Patent No. 5313339

SUMMARY OF INVENTION

Technical Problem

In the razor head 60 of FIG. 10, the pegs 64 are arranged in a zigzag manner in the longitudinal direction of the bridge walls 62. Adjacent ones of the blades in the arrangement direction of the blades are each held by the pegs 64 at a different position.

More specifically, as shown in FIG. 11, a first blade 63 includes an upper surface 63a in contact with the corresponding peg 64 at point A in the longitudinal direction of the blade 63 and a lower surface 63b in contact with the corresponding peg 64 at point B in the longitudinal direction of the blade 63. A second blade 65 adjacent to the first blade 63 includes an upper surface 65a in contact with the corresponding peg 64 at point B in the longitudinal direction of the blade 65 and a lower surface 65b in contact with the corresponding peg 64 at point A in the longitudinal direction of the blade 65.

The first and second blades 63, 65 are held by the pegs 64 at different positions. Thus, the blades may be retained in uneven states. It is an objective of the present disclosure to provide a razor head capable of retaining blades evenly.

Solution to Problem

A razor head according to an aspect of the present disclosure includes a frame, elongated blades arranged on an inner side of the frame, and two bridge walls each extending between two points of the frame in an interior of the frame, the bridge walls each including projections arranged in an arrangement direction of the blades. Each of the blades is held between adjacent ones of the projections of the bridge walls. Each of the projections includes a first flat surface that is in contact with the blade located on one side of the projection in the arrangement direction and a second flat surface that is in contact with the blade located on the other side of the projection in the arrangement direction. In each of the bridge walls, the first flat surface and the second flat surface are shifted from each other in a longitudinal direction of the blades so as not to overlap each other as viewed in the arrangement direction, and the first flat surfaces are located on the same position as viewed in the arrangement direction and the second flat surfaces are located on the same position as viewed in the arrangement direction. Each of the projections has a horizontal cross-sectional shape of a parallelogram.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a razor head according to an embodiment.

FIG. 2 is a perspective view of the frame of the razor head shown in FIG. 1.

FIG. 3 is a plan view of the frame shown in FIG. 2.

FIG. 4 is a perspective view of the frame shown in FIG. 2.

FIG. 5(A) is an enlarged view of a bridge wall of the frame shown in FIG. 3.

FIG. 5(B) is an enlarged view showing part of FIG. 5(A).

FIG. 6 is a plan view of the frame in FIG. 3 to which one blade is coupled.

FIG. 7 is a perspective view of the frame shown in FIG. 6.

FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 6.

FIG. 9 is a cross-sectional view taken along line 9-9 of FIG. 6.

FIG. 10 is a plan view of a frame of a typical razor head.

FIG. 11 is an enlarged view of a bridge wall in the frame shown in FIG. 10.

DESCRIPTION OF EMBODIMENTS

In the description and claims, the terms “first,” “second,” and the like are used to distinguish similar components. These terms are not necessarily used to represent a specific sequential or chronological order. In the description and claims, the terms “left,” “right,” “front,” “back,” “bottom (surface),” “side (wall),” “upper,” “lower,” and the like are used to indicate a relative position or structure for illustrative purposes and do not indicate a permanent position or a position when a razor head is used.

A razor head according to an embodiment will now be described.

FIGS. 1 and 2 show a razor head 10 that is coupled to a holder (not shown) and used as a razor. The razor head 10 includes a frame 20 with a rectangular outer form, a front member (lower member) 11, and a rear member (upper member) 12.

Unless otherwise specified, the longitudinal direction of the frame 20 is hereinafter simply referred to as the longitudinal direction and the lateral direction of the frame 20 is hereinafter simply referred to as the lateral direction. The first end of the frame 20 in the longitudinal direction is referred to as the left end. The second end of the frame 20 in the longitudinal direction is referred to as the right end. The lateral direction also indicates a direction in which the razor head 10 moves relative to the skin when the razor head 10 is used. The first end of the frame 20 in the lateral direction is referred to as the front end. The second end of the frame 20 in the lateral direction is referred to as the rear end. When the razor head 10 is used, the front end of the razor head 10 is located frontward from the rear end in a direction in which the razor head 10 travels. Further, the direction that is orthogonal to the longitudinal direction and the lateral direction of the frame 20 is referred to as the axial direction or the up-down direction. The direction extending from the sheet of FIG. 3 toward a person viewing the drawing, and its opposite direction is referred to as the downward direction.

Elongated blades 14 extending in the longitudinal direction are arranged on the inner side of the frame 20. The arrangement direction of the blades 14 corresponds to the lateral direction (front-rear direction) of the frame 20. For example, five blades 14 are arranged in the lateral direction at substantially equal intervals. The number of the blades 14 may be changed. For examples, there may be two to four blades 14 or may be six or more blades 14.

The front member 11 is coupled to the frame 20 along the front end of the frame 20. The rear member 12 is coupled to the frame 20 along the rear end of the frame 20. The front member 11 may include a shaving aid or a beard softener containing water-soluble components or function to pull a skin surface or raise beards. The rear member 12 may include a shaving aid or a moisturizer for skin that contains water-soluble components.

The razor head 10 includes two covers 13 that are coupled to two ends of the frame 20 in the longitudinal direction, respectively. The two covers 13 cover the two ends of each blade 14, respectively. The covers 13 restrict the blades 14 from moving upward. The razor head 10 has a substantially rectangular outer form in plan view in a state where the front member 11, the rear member 12, and the covers 13 are coupled to the frame 20. The rectangle includes four chamfered corners and four arcuate sides that are gentler than the four corners.

The frame 20 will now be described.

As shown in FIGS. 2 and 3, the frame 20 includes two opposing long side walls 21 and two opposing short side walls 22. Thus, the entire frame 20 has a rectangular outer form. The thickness direction of each long side wall 21 corresponds to the lateral direction of the frame 20. Each long side wall 21 includes two hook-shaped projections 21a that protrude outward of the frame 20. The two projections 21a are each arranged on the two ends of the corresponding long side wall 21 in the longitudinal direction. Each long side wall 21 includes a thick portion 21b located between the two projections 21a. The thick portion 21b is partially increased in thickness.

The front member 11 and the rear member 12 of the razor head 10 each include an engagement piece (not shown) and a contact portion (not shown). When the front member 11 and the rear member 12 are coupled to the frame 20, each engagement piece engages the corresponding projection 21a and each contact portion contacts the thick portion 21b. In the present embodiment, the two long side walls 21 (more specifically, the projections 21a and the thick portions 21b) each have a different shape in correspondence with the front member 11 or the rear member 12. In some examples, the two long side walls 21 may have the same shape.

The above-described “rectangular outer form” does not indicate only a rectangular outer form in a strict sense. Instead, the above-described “rectangular outer form” includes, for example, an outer form that is entirely substantially rectangular while having a shape including the projections 21a and the thick portions 21b.

The frame 20 includes a first bridge wall 23, a second bridge wall 24, and a third bridge wall 25. The first, second, and third bridge walls 23, 24, 25 each extend in the lateral direction between two points of the frame 20 in the interior of the frame 20. The two long side walls 21 each include a middle portion in the longitudinal direction. The first bridge wall 23 extends between the middle portions. The second bridge wall 24 and the third bridge wall 25 extend on opposite sides of the first bridge wall 23, respectively. That is, multiple (e.g., three) bridge walls parallel to each other are arranged on the inner side of the frame 20. The second bridge wall 24 is located closer to the first end of the frame 20 in the longitudinal direction than the first bridge wall 23. The third bridge wall 25 is located closer to the second end of the frame 20 in the longitudinal direction than the first bridge wall 23.

As shown in FIG. 3, lengths P1, P2, P3 of the first, second, and third bridge walls 23, 24, 25 in the longitudinal direction of the long side walls 21 correspond to the widths of the first, second, and third bridge walls 23, 24, 25, respectively. P1 is greater than P2 and P3.

The second bridge wall 24 and the third bridge wall 25 include narrow portions 24a and 25a, respectively. The narrow portions 24a and 25a are connected to the long side walls 21. The narrow portions 24a and 25a are shorter in the longitudinal direction than the other portions of the second bridge wall 24 and the third bridge wall 25. That is, the second bridge wall 24 and the third bridge wall 25 have a narrow width at the narrow portions 24a and 25a, respectively.

The dimensions of the narrow portions 24a and 25a are not particularly limited. For example, the dimensions of the narrow portions 24a and 25a are smaller than width P2 of the second bridge wall 24 and width P3 of the third bridge wall 25 by 0.2 mm to 1.0 mm. In other words, the narrow portions 24a and 25a may be recessed from the other portions by 0.2 mm to 1.0 mm.

The narrow portions 24a and 25a are arranged to further reduce the flow resistance of fluids flowing inside the frame 20. Further, when an additional member (e.g., holder) is coupled to the razor head 10, the narrow portions 24a and 25a can be used as the space for coupling the additional member. This prevents the additional member from protruding in the width direction of the second bridge wall 24 and the third bridge wall 25. As a result, the additional member is prevented from increasing the flow resistance.

The narrow portions 24a and 25a are portions where the second bridge wall 24 and the third bridge wall 25 are connected to the long side walls 21. This facilitates the flow of fluids along the inner edges of the long side walls 21 and thus further reduces the flow resistance of fluids.

As shown in FIGS. 2 to 4, the second bridge wall 24 and the third bridge wall 25 each include multiple (e.g., four) projections 30 that protrude in the thickness direction (upward direction) of the walls. The four projections 30 are each arranged in a row in the lateral direction. The lateral direction of the frame 20 corresponds to the longitudinal direction of the second bridge wall 24 and the third bridge wall 25. The second bridge wall 24 and the third bridge wall 25 may include the same number of projections 30. The projections 30 of each of the second bridge wall 24 and the third bridge wall 25 may have the same shape.

The first bridge wall 23 does not include the projections 30 used to couple the blades 14. That is, the first bridge wall 23 does not correspond to a bridge wall used to couple the blades 14, and the second bridge wall 24 and the third bridge wall 25 each correspond to the bridge wall used to couple the blades 14.

Leaf springs 40 protrude from the second bridge wall 24 in the longitudinal direction away from the third bridge wall 25. The leaf springs 40 are arranged in the lateral direction. Leaf springs 40 protrude from the third bridge wall 25 in the longitudinal direction away from the second bridge wall 24. The leaf springs 40 are arranged in the lateral direction. In other words, the leaf springs 40 of the second bridge wall 24 protrude toward the first end of the frame 20 in the longitudinal direction. The leaf springs 40 of the third bridge wall 25 protrude toward the second end of the frame 20 in the longitudinal direction.

The second bridge wall 24 and the third bridge wall 25 are symmetrical with respect to the first bridge wall 23. Likewise, the projections 30 and the leaf springs 40 of the second bridge wall 24 and the projections 30 and the leaf springs 40 of the third bridge wall 40 are symmetrical with respect to the first bridge wall 23. Thus, the projections 30 and the leaf springs 40 of the third bridge wall 25 will hereinafter be described, and those of the second bridge wall 24 will not be described.

The projections 30 will now be described.

FIG. 5(A) is a horizontal cross-sectional view of the projections 30 that are cut by a cut surface orthogonal to the protruding directions of the projections 30. FIG. 5(B) is an enlarged view of the section encircled by the alternate long and short dashed line in FIG. 5(A). The horizontal cross-sectional shape of each projection 30 is generally parallelogrammatic with four curved corners. Each projection 30 includes first and second flat surfaces 31, 32 that extend in the longitudinal direction and third and fourth flat surfaces 33, 34 that are inclined with respect to the first and second flat surfaces 31, 32. The first and second flat surfaces 31, 32 are a set of opposite sides parallel to each other. The third and fourth flat surfaces 33, 34 are another set of opposite sides parallel to each other.

The first and second flat surfaces 31, 32 are respectively in contact with the front blade 14 (the blade 14 on one side in the arrangement direction) and the rear blade 14 (the blade 14 on the other side in the arrangement direction). The frame 20 may include a support protrusion having a distal end surface that is a flat surface parallel to each first flat surface 31 or each second flat surface 32. The support protrusion is located in the lateral direction next to the projections 30 on the two ends in the arrangement direction. In this case, the blades 14 on the two ends in the arrangement direction are supported by the first flat surfaces 31 of the projections 30 or the second flat surfaces 32 of the projections 30 and by the distal end surface of the support protrusion.

The first flat surface 31 is a front surface of the projection 30. The second flat surface 32 is a rear surface of the projection 30. The third flat surface 33 is inclined toward the left rear. The fourth flat surface 34 is inclined toward the right front.

As viewed in the lateral direction, the first flat surfaces 31 on the third bridge wall 25 are located on the same position. As viewed in the lateral direction, the second flat surfaces 32 on the third bridge wall 25 are located on the same position. In other words, the four first flat surfaces 31 on the third bridge wall 25 are located on the same position in the longitudinal direction and the four second flat surfaces 32 on the third bridge wall 25 are located on the same position in the longitudinal direction.

There is a gap S1 between the first flat surface 31 and the second flat surface 32 that hold each blade 14 (hereinafter also referred to as the gap between flat surfaces). Each blade 14 is inserted into the gap S1 so that the corresponding two projections 30 hold the blade 14. This causes the blade 14 to be coupled to the third bridge wall 25.

The term “hold” does not only indicate a state in which two projections 30 hold the blade 14 so as to be immovable in the axial direction, but also indicate a state in which two projections 30 hold the blade 14 so as to be slidable in the axial direction. For example, during use of the razor, the pressure produced by the blade 14 pressing the skin may cause the blade 14 to slide in the axial direction.

The gap S1 may be changed in correspondence with the thickness of the blade 14. For example, the gap S1 may range from 0.025 mm to 1.0 mm or may range from 0.1 mm to 0.5 mm. When the gap S1 falls within these value ranges, the blade 14 having a thickness of approximately 0.02 mm to 0.96 mm is easily inserted into the gap S1 and easily held by the projections 30.

Length T1 of the first flat surface 31 in the longitudinal direction is equal to length T2 of the second flat surface 32 in the longitudinal direction. The first flat surface 31 and the second flat surface 32 that are in contact with each blade 14 are shifted from each other in the longitudinal direction so as not to overlap each other as viewed in the lateral direction. In other words, the first flat surface 31 and the second flat surface 32 of each projection 30 are shifted from each other in the longitudinal direction so as not to overlap each other as viewed in the lateral direction. Thus, the first flat surface 31 and the second flat surface 32 that hold each blade 14 do not oppose each other in a state where the blade 14 is removed.

Length T1 of the first flat surface 31 and length T2 of the second flat surface 32 may be changed. For example, T1 and T2 may range from 0.2 mm to 2.0 mm or may range from 0.3 mm to 1.4 mm. Length T1 may be equal to or different from length T2.

As shown in FIG. 5, since each first flat surface 31 and the corresponding second flat surface 32 are shifted from each other so as not to overlap each other in the longitudinal direction, a minimum interval W between adjacent ones of the projections 30 in the lateral direction (hereinafter referred to as the minimum interval between projections) is greater than the gap S1.

FIG. 5 shows a separation distance U between the second flat surface 32 of one of adjacent two projections 30 and the first flat surface 31 of the other projection 30 in the longitudinal direction (hereinafter also referred to as the separation distance between two flat surfaces). The separation distance U may be changed. For example, the separation distance U may range from 0.01 mm to 1.0 mm or may range from 0.05 mm to 0.8 mm. The separation distance U falling within these value ranges shifts the first flat surface 31 and the second flat surface 32 from each other so as not overlap each other in the longitudinal direction and relatively reduces width P3 of the third bridge wall 25.

The leaf springs 40 will now be described.

As shown in FIGS. 3 and 4, the third bridge wall 25 includes five leaf springs 40. Each of the leaf springs 40 is a plate member extending in the longitudinal direction. The leaf spring 40 includes a basal end connected to the third bridge wall 25 and a distal end protruding in a direction away from the second bridge wall 24. More specifically, the distal end of the leaf spring 40 protrudes upward as the distal end becomes farther from the basal end of the leaf spring 40. Thus, the leaf spring 40 is inclined with respect to the longitudinal direction. The distal end of the leaf spring 40 is a free end. This allows the leaf spring 40 to be elastically deformable in the axial direction.

When the frame 20 is seen from above, each leaf spring 40 is slightly inclined such that its distal end is closer to the second end in the lateral direction than its basal end. In other words, the direction in which the leaf spring 40 extends is slightly inclined with respect to the longitudinal direction such that the distal end is located on the rear side of the basal end.

The distal end of each leaf spring 40 includes a protrusion 41 that protrudes upward. As described below, the protrusion 41 is a support that supports the blade 14.

The mechanism of the frame 20 retaining the blade 14 will now be described.

Referring to FIGS. 6 and 7, each of the second bridge wall 24 and the third bridge wall 25 retains the blades 14 with four projections 30 arranged in the lateral direction. Each blade 14 is inserted into the gap between the flat surfaces of adjacent ones of the projections 30 in the lateral direction. Each blade 14 includes a first end in the longitudinal direction retained by the second bridge wall 24 and a second end in the longitudinal direction retained by the third bridge wall 25. Thus, in the present embodiment, the two bridge walls (i.e., second bridge wall 24 and the third bridge wall 25) retain the blades 14. FIGS. 6 and 7 show the frame 20 to which only one blade 14 is coupled.

As shown in FIGS. 8 and 9, the blade 14 includes a plate-shaped body 14a held by the projections 30 and a blade portion 14b joined to the upper edge of the body 14a. The body 14a includes a bent portion (curved portion) 14c that is bent frontward. The blade portion 14b is joined to the bent portion 14c.

As shown in FIG. 9, when the blade 14 is inserted into the gap between the flat surfaces, a lower surface P of the bent portion 14c is in contact with the protrusion 41 of the leaf spring 40. In other words, the blade 14 is supported by the protrusion 41 of the leaf spring 40.

As shown in FIG. 8, each projection 30 includes a distal end surface 30a that is a flat surface inclined with respect to the axial direction. The distal end surface 30a is substantially parallel to a lower surface of the blade portion 14b. The space between the lower surface P of the bent portion 14c and the distal end surface 30a of the projection 30 includes a gap S2. The blade 14 is permitted to move in the range of the gap S2 in the axial direction as the leaf spring 40 elastically deforms.

Since the distal end of each leaf spring 40 is slightly inclined rearward when the frame 20 is seen from above, the blade 14 supported by the leaf spring 40 is slightly biased toward the projection 30 located on the rear side of the blade 14. This allows the blade 14 to be retained more stably.

The material of the razor head 10 is not particularly limited. The razor head 10 made of resin (plastic) is excellent in moldability. Examples of the resin used as the material of the razor head 10 include ABS, polypropylene, polystyrene, polyacetal, and nylon.

The material of each blade 14 is not particularly limited. For example, the blade 14 may be made of metal, ceramics, or resin. Examples of the metal used as the material of the blade 14 include stainless steel and titanium. Examples of the ceramics used as the material of the blade 14 include zirconia, aluminum oxide, and silicon nitride. The resin used as the material of the blade 14 includes the same resin of the razor head 10.

The arrangement of the second bridge wall 24 and the third bridge wall 25 will now be described.

As shown in FIG. 3, the second bridge wall 24 and the third bridge wall 25 are located at positions excluding the middle portion and the two ends of the frame 20 in the longitudinal direction. In other words, the second bridge wall 24 and the third bridge wall 25 are located at positions separated from the first bridge wall 23, which is located at the middle of the frame 20 in the longitudinal direction, and the two short side walls 22.

When the position in the frame 20 in the longitudinal direction is represented by a percentage, the position of the middle of the frame 20 in the longitudinal direction is 0% and the positions of the two ends of the frame 20 in the longitudinal direction (more specifically, the inner surfaces of the two short side walls 22) are 100%. In this case, the second bridge wall 24 and the third bridge wall 25 may be arranged in a predetermined range between the two ends and the middle. More specifically, the second bridge wall 24 and the third bridge wall 25 may be arranged in a range from 30% to 90% or may be arranged in a range from 50% to 70%. In this case, it is preferred that the second bridge wall 24 and the third bridge wall 25 be in the range from 30% to 90% or in the range from 50% to 70%.

In this case, only the two bridge walls, namely, the second bridge wall 24 and the third bridge wall 25 hold the blade 14 while limiting flexing of the blade 14 in a favorable manner.

As shown in FIG. 6, the arrangement of the second bridge wall 24 and the third bridge wall 25 produces a space Z between each of the two ends of the blade 14 in the longitudinal direction and the corresponding one of the two short side walls 22. That is, the two ends of the blade 14 in the longitudinal direction are separated from the frame 20. Thus, as compared with when the two ends of the blade 14 in the longitudinal direction are respectively in contact with the two short side walls 22, the spaces Z through which fluids flow inside the frame 20 are wider. Even in a case where burrs are left at the body 14a or at the two ends of the blade portion 14b in the longitudinal direction, the spaces Z allow the blade 14 to be smoothly inserted into the gap between the flat surfaces without being interfered by the burrs. Further, even in a case where the blade 14 moves in the axial direction as the leaf spring 40 elastically deforms, the blade 14 is prevented from contacting the inner surface of the frame 20.

Referring to FIG. 3, the entire width of the razor head 10 (the length of the razor head 10 from the first end to the second end in the longitudinal direction) may be changed. For example, the entire width may range from approximately 25 mm to 80 mm and may be about 41.5 mm. In correspondence with the dimension of the entire width of the razor head 10, the other dimensions may be enlarged or reduced at the same ratio (in a similar shape) and the ratio may be changed.

The length of the razor head 10 in the lateral direction (the length of the frame 20 in the lateral direction excluding the projections 21a and the thick portion 21b) may be changed. For example, the length of the razor head 10 in the lateral direction may range, for example, from approximately 4.0 mm to 12.0 mm and may be about 8.0 mm.

Width P1 of the first bridge wall 23 may range, for example, from approximately 2.0 mm to 4.0 mm and may be about 3.2 mm. The arrangement of the first bridge wall 23 increases the rigidity of the razor head 10.

Width P2 of the second bridge wall 24 and the width P3 of the third bridge wall 25 may each range from, for example, approximately 1.6 mm to 4.0 mm and may be about 3.2 mm. Widths P2 and P3 may each be less than or equal to 10% of the entire width of the razor head 10. This allows fluids (e.g., beard trimmings, dead skin, or water containing shaving agent) to be smoothly discharged from the surface of the razor head 10 in contact with the skin (upper surface) toward the opposite surface (bottom surface).

The operation and advantages of the present embodiment will now be described.

(1) As the projections 30 of the second bridge wall 24 are seen in the lateral direction, the first flat surfaces 31 are located at the same position and the second flat surfaces 32 are located at the same position. The projections 30 of the third bridge wall 25 are arranged in the same manner.

This structure allows the projections 30 to retain the blades 14 evenly. More specifically, in the case of using a razor including blades, the blades tend to receive a load at the same position in the longitudinal direction. When the blades are evenly retained, the blades are flexed more evenly. This makes the feel of the shaver on the skin of the user more even and thus provides comfort to the user. Further, the blades are flexed more evenly so that the intervals between the blades are more even. If the intervals between the blades are partially narrow, the narrow parts tend to be clogged by, for example, beard trimmings, dead skin, or shaving agent. By preventing such clogging, the razor head in direct contact with the user is kept clean (i.e., hygienic). This is also advantageous to the user.

(2) The first flat surface 31 of one of adjacent two projections 30 in the lateral direction and the second flat surface 32 of the other one of the two projections 30 are shifted from each other in the longitudinal direction so as not to overlap each other. In this structure, the first flat surface 31 and the second flat surface 32 that hold each blade 14 do not oppose each other. Thus, as compared with a structure in which the first flat surface 31 and the second flat surface 32 oppose each other, the minimum interval W is relatively large. This limits clogging of foreign matter between adjacent ones of the projections 30. Even if the gap S1 is smaller than a reference value in a range of tolerance, the blade 14 is easily inserted into the gap between the flat surfaces.

(3) In the longitudinal direction of the blade 14, the first flat surface 31 and the second flat surface 32 of each projection 30 are equal to each other. This allows the opposite surfaces of the blade to be held in a substantially even manner.

Further, the minimum interval W is relatively large. This limits clogging of foreign matter between the projections 30. Furthermore, since the minimum interval W is large, a portion where the minimum interval W is provided is relatively large during production of a mold for forming the frame 20. This improves the strength of the mold.

(4) Each blade 14 is held by the first flat surface 31 of one of two projections 30 and the second flat surface 32 of the other one of the two projections 30. Thus, as compared with, for example, a structure in which the blade 14 is held by two curved surfaces, the blade 14 is held more stably. This keeps the blade edge in contact with the skin in a favorable manner and thus continues to provide comfort to the user for a long period of time. Further, wear in the projections 30 caused by shifting of the positions of the blade 14 is limited. Furthermore, chattering of the blade 14 caused by the wear of the projections 30 is limited. Chattering of the blade 14 makes the user uncomfortable. Thus, comfort is provided to the user also by limiting the chattering of the blade 14.

(5) Each projection 30 has a horizontal cross-sectional shape of a parallelogram. The third and fourth flat surfaces 33, 34 are inclined with respect to the moving direction (lateral direction) of the razor head 10. This reduces the flow resistance of solids or fluids (e.g., beard trimmings, dead skin, or shaving agent) in contact with the third and fourth flat surfaces 33, 34 and thus allows the solids or fluids to flow more quickly.

(6) The space Z is provided between each of the two ends of the blade 14 in the longitudinal direction and the corresponding one of the two short side walls 22. Thus, fluids (e.g., water) easily pass through the spaces Z inside the frame 20. Even if burrs are left, for example, at the body 14a or at the two ends of the blade portion 14b in the longitudinal direction, the spaces Z make the burrs non-interfering. This allows the blade 14 to be smoothly inserted into the gap between the flat surfaces. Further, even if the blade 14 moves in the axial direction as the leaf spring 40 elastically deforms, the blade 14 is prevented from contacting the inner surface of the frame 20.

(7) Each of the second bridge wall 24 and the third bridge wall 25 includes the leaf springs 40 that protrude in the direction away from the other one of the second and third bridge walls 24 and 25. Each leaf spring 40 supports the corresponding blade 14. This allows the leaf spring 40 to support parts in the periphery of the two ends of the blade 14 in the longitudinal direction while leaving the space Z between each of the two ends of the blade 14 in the longitudinal direction and the corresponding one of the two short side walls 22. Further, the second bridge wall 24 and the third bridge wall 25 respectively support parts in the periphery of the two ends of the elongated blade 14 and thus further stabilizes the blade 14. Even when, for example, the blade 14 moves as the leaf spring 40 elastically deforms, the blade 14 is supported stably.

(8) The blades 14 are supported by two bridge walls. Thus, as compared with when the blades 14 are supported by three or more bridge walls, the number of the projections 30 of the bridge walls is relatively small. That is, while a larger number of the projections 30 is preferred for stably retaining the blades 14, a larger number of the projections 30 would increase the flow resistance of fluids flowing inside the frame 20. Setting the number of bridge walls including projections 30 to two reduces the flow resistance and stably retains the blades 14.

When the flow resistance of fluids flowing inside the frame 20 is small, fluids (e.g., beard trimmings, dead skin, or water containing shaving agent) are smoothly discharged from the surface of the razor head 10 in direct contact with the skin toward the bottom surface, which is opposite from the skin contact surface. Thus, the razor head in direct contact with the user is kept clean (i.e., hygienic). This is also advantageous to the user. Further, the two bridge walls that retain the blades 14 are located at the positions excluding the middle portion and the two ends of the frame 20 in the longitudinal direction. Thus, the flexing of the blades 14 are limited. This keeps each blade edge in contact with the skin in a favorable manner and thus continues to provide comfort to the user for a long period of time.

(9) In a case where the position of the frame 20 in the longitudinal direction is represented by a percentage, when the middle in the longitudinal direction is 0% and the two ends (the inner surfaces of the short side walls 22) in the longitudinal direction are 100%, each of the second bridge wall 24 and the third bridge wall 25 is arranged in a range from 30% to 90%. This limits the flexing of the blades 14 in a favorable manner. Thus, each blade edge is kept in contact with the skin in a favorable manner for a longer period of time. This continues to provide comfort to the user for a longer period of time.

The present embodiment may be modified as follows. The present embodiment and the following modifications can be combined as long as they remain technically consistent with each other.

As viewed in the lateral direction, the first flat surfaces 31 and the second flat surfaces 32 arranged in each bridge wall may partially overlap each other in the longitudinal direction. Even in this case, if the gap S1 is smaller than a reference value in a range of tolerance, each blade 14 is easily inserted into the gap between the flat surfaces by reducing the regions where the first flat surfaces 31 oppose the second flat surfaces 32.

The horizontal cross-sectional shape of each projection 30 may be changed. For example, the inclining direction of the third and fourth flat surfaces 33, 34 of each projection 30 may be reversed such that the second flat surface 32 of each projection 30 is closer to the middle of the frame 20 in the longitudinal direction than the first flat surface 31.

The horizontal cross-sectional shape of each projection 30 does not have to be parallelogrammatic. For example, the third flat surface 33 and the fourth flat surface 34 of each projection 30 do not have to be parallel to each other.

The third flat surface 33 and the fourth flat surface 34 of each projection 30 may be changed to curved surfaces recessed such that the middle portions of the curved surfaces become close to each other. In this case, since each projection 30 is relatively thin, the frame 20 is reduced in weight.

The third flat surface 33 and the fourth flat surface 34 of each projection 30 may be changed to curved surfaces bulged such that the middle portions of the curved surfaces are separated from each other. This facilitates the production of a mold. Further, since each projection 30 is relatively thick, the mechanical strength of the frame 20 improves.

In the third flat surface 33 and the fourth flat surface 34 of each projection 30, one of the surfaces may be a curved surface with a recessed middle portion and the other surface may be a curved surface with a bulged middle portion.

The two ends of the blades 14 in the longitudinal direction may be in contact with the two short side walls 22, respectively, Further, the two short side walls 22 may retain the two ends of the blades 14 in the longitudinal direction, respectively. Thus, the spaces Z do not have to be provided.

The number of the projections 30 of each of the second bridge wall 24 and the third bridge wall 25 may be changed to, for example, two, three, five, or more.

The frame 20 does not need to include the first bridge wall 23. Alternatively, the frame 20 may include another bridge wall in addition to the first bridge wall 23, the second bridge wall 24, and the third bridge wall 25.

In the same manner as the second bridge wall 24 and the third bridge wall 25, the first bridge wall 23 may include projections 30.

Each of the second bridge wall 24 and the third bridge wall 25 may include leaf springs 40 that protrude in a direction closer to the other one of the second and third bridge walls 24 and 25.

The second bridge wall 24 and the third bridge wall 25 do not have to include the leaf springs 40. That is, the blades 14 may be fixed such that the blades 14 are immovable in the axial direction.

Each blade 14 may be an undivided component in which the body 14a and the blade portion 14b are integrally molded.

One or both of the narrow portions 24a and 25a of the second bridge wall 24 and the third bridge wall 25 may be omitted.

The narrow portions 24a and 25a do not have to be located at the positions of the above-described embodiment. For example, the narrow portions 24a and 25a may be located at the two ends of the second and third bridge walls 24, 25 in the longitudinal direction or may be located at positions separated from the ends.

Claims

1. A razor head, comprising: a frame;elongated blades arranged on an inner side of the frame; andtwo bridge walls each extending between two points of the frame in an interior of the frame, the bridge walls each including projections arranged in an arrangement direction of the blades, whereineach of the blades is held between adjacent ones of the projections of the bridge walls,each of the projections includes: a first flat surface that is in contact with the blade located on one side of the projection in the arrangement direction;a second flat surface that is in contact with the blade located on the other side of the projection in the arrangement direction; anda third flat surface and a fourth flat surface that are inclined with respect to the first flat surface and the second flat surface,the first flat surface is parallel to the second flat surface,the third flat surface is parallel to the fourth flat surface,in each of the bridge walls, the first flat surface and the second flat surface are shifted from each other in a longitudinal direction of the blades so as not to overlap each other as viewed in the arrangement direction, andthe first flat surfaces are located on the same position as viewed in the arrangement direction and the second flat surfaces are located on the same position as viewed in the arrangement direction.

2. The razor head according to claim 1, wherein the first flat surface and the second flat surface of each of the projections has the same length in the longitudinal direction of the blades.

3. The razor head according to claim 1, wherein a space is provided between the frame and each of two ends of the blades in the longitudinal direction.

4. The razor head according to claim 3, wherein each of the two bridge walls includes leaf springs that protrude in a direction away from the other one of the bridge walls, andeach of the leaf springs supports a corresponding one of the blades.