SAFETY RAZORS
20230321853 · 2023-10-12
Assignee
Inventors
- Michaela KOHUT (Hamburg, DE)
- Alexander KRÜMKE (Hamburg, DE)
- Martin WEHMANN (Norderstedt, DE)
- Josef GLEIXNER (Nabburg, DE)
- Sander PATJE (Zuidwolde, NL)
Cpc classification
B26B21/522
PERFORMING OPERATIONS; TRANSPORTING
B26B21/52
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A safety razor handle with a chunky, non-elongate handle body comprising a core layer made of a plurality of sub-layers and an outer layer at least substantially covering the core layer.
Claims
1. A safety razor handle with a chunky, non-elongate handle body comprising a core layermade of a plurality of sub-layers and an outer layerat least substantially covering the core layer.
2. The safety razor handle according to claim 1, wherein the plurality of sub-layers is created by injection moulding of one or more subsequent sub-layers onto a first sub-layer.
3. The safety razor handle according to claim 1, wherein the plurality of sub-layers is of a same material.
4. The safety razor handle according to claim 1, wherein the core layer is provided by between two and 6 sub-layers .
5. The safety razor handle according to claim 1, wherein a first sub-layer extends in a flat round shape from a handle attachment portion, any intermediate sub-layers extend in a flat round shape to one side or another of the first sub-layer and a final sublayer extends to at least partially surround the first sub-layer and the any intermediate sub-layers.
6. The safety razor handle according to claim 1, wherein an interlocking connection is provided between two of the plurality of sub-layers.
7. The safety razor handle according to claim 1, wherein a thickness of the plurality of sub-layers is at least substantially constant over a majority of their extent.
8. The safety razor handle according to claim 1, wherein the outer layeris of a softer material and the core layer is of one or more harder materials, and wherein both layers are translucent.
9. The safety razor handle according to claim 8, wherein borders between the plurality of sub-layers and a border between the core layer and the outer layer cannot be easily distinguished by a naked eye.
10. The safety razor handle according to claim 1, wherein the outer layerforms a complete covering over the core layer on an outer surface of the handle body.
11. The safety razor handle according to claim 1, wherein the core layeris thicker than the outer layer and wherein the outer layer is of substantially constant thickness at least over a majority of the core layer.
12. The safety razor handle according to claim 11, wherein the substantially constant thickness of the outer layer is between about 1 and 7 mm .
13. The safety razor handle according to claim 1, wherein the core layeris of an overall non-elongate, bulbous shape.
14. The safety razor handle according to claim 1, further comprising a handle connecting structurefor a cartridge and wherein the outer layerincludes an opening leading to a recess in the core layer housing the handle connecting structure.
15. The safety razor handle according to claim 1, further comprising a friction-enhancing finish on the outer layer, a friction-enhancing additive to the outer layer or a friction-enhancing surface coating on the outer layer.
16. The safety razor handle according to claim 1, wherein the handle body is bulbous in two orthogonal directions, between an end surfaceand a further end surfaceopposite to the end surface, the two opposite end surfaces being connected by a convex side surfacewhich widens towards a centre of the handle body.
17. The safety razor handle according to claim 16, wherein there is a single continuous side surfacebetween the two opposite end surfaces, wherein the further end surface is a front end surfacefacing in an opposite direction to a shaving direction in use and the end surfaceis a rear end surface facing in the shaving direction in use, and wherein a handle connecting structure is on the continuous side surface closer to the front end surface than to the rear end surface.
18. The safety razor handle according to claim 16, wherein one or both end surfaces are flat and the end surfaces are parallel.
19. The safety razor handle according to claim 1, wherein the handle bodyis in a form of a barrel shape, with a skewed barrel surface between two end surfaces, and wherein a largest diameter of the barrel shape is between a third and three times a length of a longitudinal axis of the barrel shape .
20. The safety razor handle according to claim 1, wherein the handle bodycomprises: an underneath surface portion comprising a handle connecting structure; a front surface and opposite rear surface portion; a top surface portion and side surface portions, one directed to either side of the handle body or cartridge width in use; wherein the top surface portion, underneath surface portion and side surface portions together form a continuous smooth surface which is a substantially cylindrical or substantially ellipsoid or substantially partially spherical surface; or whereina distance between the front surface portion and rear surface portion is between one third and three times a largest dimension of a largest cross section through the continuous smooth surface.
21. A safety razor comprising the safety razor handle according to claim 1, connected to a cartridge via a handle connecting structure.
22. A method of manufacturing a chunky, non-elongate handle body of a safety razor handle comprising sequentially moulding a plurality of sub-layers of a core layer and then moulding an outer layerat least substantially covering the core layer.
23. The method according to claim 22, wherein the handle body is injection moulded using an injection moulding apparatus with a rotating hub.
24. The method according to claim 23, wherein the rotating hub holdshandle bodies during moulding and rotates them to index between moulding positions in the injection moulding apparatus, each moulding position including a cavity which adds a sub-layer or layer to each handle body.
25. The method according to claim 24, wherein a finished handle body is ejected at an ejection position of the injection moulding apparatus.
26. The method according to claim 24, wherein material is injected into all the cavities at the same time.
27. The method according to claim 26, wherein the cavities are constructed so that each of the plurality of sub-layers and the outer layer takes a same amount of time to cool.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0059] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.
[0060] Reference will now be made to
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DETAILED DESCRIPTION OF THE INVENTION
[0078] The following detailed description refers to the accompanying drawings that illustrate examples and embodiments consistent with this invention. Other embodiments are possible, and modifications can be made to the embodiments within the spirit and scope of the invention. Therefore, the detailed description is not meant to limit the invention.
[0079] The term “underneath” is used to describe features of the handle, cartridge or a lubrapad that are positioned on the skin-contacting side of the cartridge or lubrapad (i.e., on a shaving-side or underneath of the handle, cartridge or lubrapad) in use, and the term “top” is used to describe features of the handle, cartridge or lubrapad that are positioned on a side opposite the skin-contacting side of the cartridge or lubrapad in use (i.e., on a user side or on top of the cartridge or lubrapad). The terms “front”, “rear”, and “side(s)” are used herein with reference to the shaving direction, i.e., the direction in which the cartridge and lubrapad are intended to be moved during shaving. In particular, the term “front” means facing in the shaving direction, “rear” means facing in the opposite direction to the shaving direction, and “side(s)” mean to either side in the shaving direction. In general, the cartridge is positioned at the front of the razor in use and the razor is pulled backwards across the skin (with the cartridge last).
[0080]
[0081] The handle includes the handle body 50 and a handle stem or handle connecting structure 59.
[0082] The handle body in this example is made up of a multi-layered hard plastic core 80 and outer layer or skin 70. The soft skin is made from a translucent silicone or TPE (TPE-Versaflex CL30 from Polyone in this example). The material is translucent and light coloured, so light can easily transmit through it. The translucent material is not only attractive but also practical in allowing parts behind the body to be glimpsed through the body and thus aiding user orientation and shaving performance. The surface looks and feels silky and non-sticky to the hands of the user. The core is made of hard plastic such as styrene butadiene copolymer (in this example SBC -KR03-Resin from INEOS Styrosolution). Due to the chemical properties of these materials it is almost impossible to visually distinguish the border between hard core and soft skin and the borders between the sub-layers in the final product. The thickness of the outer layer is around 4 mm in this embodiment.
[0083] The handle body is formed by either LSR or injection or compression molded as explained in more detail later. The full razor weighs around 40 to 60 grams, preferably around 55 grams and the outer skin has a Shore A hardness of around 30, to give a squeezable feel and pleasurable tactile sensation when gripped by the user. It may include a logo on the front surface (the further end surface which is on the top when the razor is in the upright position). The inner core has a higher Shore A hardness (over 70), for example a Shore D hardness of 63.
[0084] When the razor is in use, the flat end surface 52 forms the rear surface of the razor, as shown in
[0085] Opposite to the flat end surface is a further flat end surface 51. This is a front surface portion when the razor is in use, as shown in
[0086] These two opposite surfaces are parallel, and are separated by a single continuous side surface 56. As can be seen clearly from
[0087] In use, the side surface of the handle body 56 has a curved underneath portion 53 as shown in
[0088] As shown best in
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[0090] The handle body has a flat end surface 52 on which it can rest stably upright on a (substantially) horizontal surface, as shown in
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[0092] The handle stem may be fixedly connected to the handle body, such as by chemical connection.
[0093] The cartridge of these figures includes a lubricating strip or lubrapad 12 as an additional or integral part of the cartridge, for example with a single frame both surrounding the blades and providing a back support for the lubrapad. The end surface has been shown and described as flat, but may alternatively be curved or uneven, if there is no requirement for the razor to be stable in an upright position.
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[0096] Some advantageous dimensions of the safety razor which give good maneuverability in the human hand are shown in
[0097] The maximum length of the handle body parallel to the skin surface in use (with the end surface at 45° to the skin surface) is from 40 to 80 mm, preferably between 56 and 64 mm, for example 61 mm. This is measured from the foremost extent of the front (the lowest portion of the front or further end surface) to the rearmost extent of the rear (the highest portion of the rear or end surface which rests on the horizontal plane when the razor is upright). The maximum height of the handle body in use is between 25 and 55 mm, preferably between 36 and 41 mm, for example 39 mm.
[0098] The distance between the end surfaces is between 25 and 45 mm, preferably between 31 and 36 mm, for example 35 mm. The handle stem (or other interface between the handle and cartridge) starts at 3 to 10, preferably 5 to 6 mm along the underneath portion of the side surface in use from the front surface. The maximum width of the handle body measured parallel to the end surfaces is between 35 and 60 mm, preferably between 42 and 48 mm, for example 46 mm.
[0099] If the cartridge is flat on the skin in use, the end surfaces extend at between 35 to 55, preferably at 45 degrees to the skin surface.
[0100] The cartridge footprint may have a length of around 25-60 mm in the blade direction, preferably around 40-50 mm and a depth orthogonal to the blade direction from the front to the rear of the cartridge of around 10-30 mm, preferably 15-23 mm. Whilst the cartridge size may have a natural maximum linked to its function, the handle body and in particular the handle body extent in the blade direction is not similarly limited.
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[0103] The safety razor handle comprises (as before) an underneath surface portion 53 facing the skin of the user in use and comprising a connecting structure (such as a stem 61) for attachment to a blade unit; a front surface portion 51 facing in the opposite direction from the shaving direction in use; a rear surface portion 52 facing in the shaving direction in use; a top surface portion 54 and lateral surface portions 55, one directed to either side of the blade length in use; wherein the top surface portion, underneath surface portion and side surface portions together form a continuous smooth surface which is a substantially cylindrical or substantially ellipsoid or substantially partially spherical surface. The distance between the front surface portion and rear surface portion is between one third and three times, preferably between a half and twice, the largest dimension of the largest cross section through the continuous smooth surface.
[0104] The term substantially cylindrical or substantially ellipsoid or substantially partially spherical surface is used to describe a shape which is close to cylindrical or ellipsoid or partially spherical form, for example with a 10% deviation from one of those forms. In one measure, a section (or all sections) taken vertically through the continuous smooth surface (for example in a direction parallel to the blade length) overlaps with a circle or ellipse drawn to just cover the whole section with the areas of the circle or ellipse which are not covered by the section being up to one tenth of the area of the section.
[0105] The front and rear surface portions may be flat or concave. The front surface may extend to the guard side of the attachment to the blade unit, and may conveniently be provided with a logo and/or instructions. It may extend substantially parallel to the rear surface portion and preferably substantially parallel to a main direction (in terms of longest extent) of the stem.
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[0107] In one razor embodiment, the handle connecting structure for attachment to the blade unit and corresponding structure on the blade unit/cartridge allow relative movement, such as pivoting movement, between the handle and the blade unit. For example the connection may have some play, or one or both of the attachment means or corresponding means may be flexible.
[0108] In this embodiment the safety razor comprises a lubrapad with a lubrapad body 22 adjacent to the blade unit, and extending along a guard of the blade unit and in front of the guard in use. The lubrapad body 22 has a greatest width and/or depth in the blade direction at the guard, the body width and/or depth reducing in a smooth convex curve away from the guard to a curved front portion of the body.
[0109] In a further definition of the handle shown in all these Figures, invention embodiments provide a safety razor handle wherein the body has a shape which is rounded and chunky (or bulbous), extending with perpendicular length I, width w and height h, wherein none of the maximum length, width and height of the body is more than 2, 3 or 4 times the size of the maximum in the other two dimensions.
[0110] For example, the height may be the largest vertical cross section through the side smooth surface previously defined, the width may be the largest horizontal cross section through the side surface and the length may be the horizontal distance (parallel with the shaving plane) between the end surfaces.
[0111] Any of the previous features of the handle and safety razor (and safety razor system) may be applied to these embodiments.
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[0113] The first layer 81 includes the handle attachment area surrounding the recess 58 and a generally flat round “plate” shape extending from this area. The intermediate sub-layers have a purely plate-like shape. The intermediate sub-layers can stack like plates above and/or below the initial plate of the first sub-layer. The second layer 82 is of a plate shape and is added below the first plate shape, with some interlocking for better connection. The third layer 83 is also a plate shape. The fourth layer 84 surrounds all the previous layers to give a smooth outer for the skin, with fewer joins. The fifth layer provides the final skin. Each of these sub-layers and the outer layer are designed to have the same cooling time, within a tolerance margin of for example 5 seconds, so that the cooling part of the cycle time (which is constrained as the cooling time which is the longest for all the layers) is used efficiently.
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[0116] The injection molding apparatus has a rotating hub (or core) 163 holding the handle bodies during molding in cavities 164. The hub rotates the bodies to index them between molding positions in the apparatus shown as 1, 2, 3, 4 and 5. Each position includes a cavity which adds a sub-layer or layer to the handle body. Advantageously, a single core material inlet 161 supplies positions, 1, 2, 3 and 4 with the molten material for the core sub-layers. Thus in this embodiment all the sub-layers are made of the same material. An outer layer material inlet 162 simultaneously supplies the cavity at position 5 with material for the outer layer (skin). The finished handle body is ejected at ejection position 6 via ejection chute 165 of the injection molding apparatus.
[0117] In more detail, a first sub-layer is molded in a cavity at 1, an intermediate sub-layer is moulded at 2, a further intermediate sub-layer is molded at 3, a final sub-layer is molded at 4 and a thin outer skin is molded at 5, with the handle body being ejected at 6.
[0118] As will be apparent, material is injected into all the cavities (and the finished handle body is ejected) at the same time. In this way, each 60 degree index of the hub ejects another finished handle body and adds a layer to five unfinished handle bodies, one at each molding position. When the mold is closed, plastic is injected into all the cavities simultaneously. In parallel, the finished handle is ejected from the mold. After injection, the plastic is cooled in the mold for about 50 seconds before the tool opens to rotate the hub. When the mold is opened again, the hub can rotate. The hub carries the unfinished handle bodies in a spoke arrangement extending radially outwards, each body attached to a spoke of the hub. When one injection has just taken place and the finished handle body has been ejected, it leaves a bare spoke in the ejection position 6, and the build-up of layers at positions 1 to 5.
[0119] Viewing the overall process for a single handle body, the cavity in position 1 is structured such that the molten core material forms the first core sub-layer 81. Following a first injection of molten hard core material and the passing of a period of time to allow the mould and the sub-layer to cool, the rotating/indexing hub opens and rotates 60° in a clockwise direction, so that that first sub-layer now occupies cavity at position 2. Similarly, the five other spokes will have rotated through 60° to occupy the next indexed position.
[0120] The cavity at position 2 is structured such that molten hard core material injected through core material inlet 161 reaches the cavity at position 2 and forms the second core sublayer 82 to one side of the first core sublayer 81.
[0121] The cooling, rotation, and injection of molten material proceeds a further 2 times, forming the third and fourth core sublayers 83, 84 in the same manner as previously described, except that for the fourth sub-layer, the molten material surrounds all the previous sub-layers, rather than being formed to one side.
[0122] The next cooling, rotating, and injection of molten material step takes the part-finished handle body into the cavity at position 5, into which molten soft material is injected to form the skin 70, surrounding the fourth core sublayer.
[0123] Upon a further cooling, and rotating, the handle body comprising all four sublayers and outer layer 70 is ejected from cavity position 6 through the finished product ejection chute 165.
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Materials
[0132] In any of the handle definitions, the handle body may comprise an outer molded translucent or transparent layer of elastomeric material such as silicone, polyurethane as TPU (thermoplastic polyurethane), PU (Polyurethane), TPE (thermoplastic elastomer), PETG (Polyethylene Terephthalate Glycol), TPS or rubber (such as liquid silicone rubber or compression silicone rubber) for example having a Shore A hardness of around 5 to 80, preferably a squeezable 30 Shore A under the ASTM D2240-00 testing standard. As used herein, TPEs are thermoplastic elastomers, for example thermoplastic elastomers selected from the group of styrenic block copolymers (TPE-s including TPE SBS and the hydrogenated version of TPE-SEBS; e.g. Thermoplast K, Thermolast M, Sofprene, or Laprene), thermoplastic olefins (TPE-o; e.g. For-Tec E), elastomeric alloys (TPE-v or TPV; e.g. Thermolast A, Thermolast V, Hipex, Forprene, Termoton-V, or Vegaprene), thermoplastic polyurethanes (TPU; e.g. Copec), thermoplastic copolyesters (TPE-E), thermoplastic polyamides and mixtures thereof. A preferred material is TPE-Versaflex CL30 from Polyone. As used herein, silicones (or polysiloxanes) are polymers that include any inert, synthetic compound made up of repeating units of siloxane.
[0133] These materials give a superior tactile feeling with a material that is soft and yet strong due to the shape of the handle. Moreover, the body being translucent or even transparent allows the user to gain a better feel of the positioning of the handle (and thus of the attached blade unit) with respect to the hand and to the skin to be shaved.
[0134] In any of the handle definitions, the core may be fabricated in transparent or opaque i.e. virgin or recycled polyethylene terephthalate, polycarbonate, polystyrene, styrene-acrylonitrile, Acrylonitrile-ButadieneStyrene (ABS), or polymethyl methacrylate or SBC (Styrene Butadiene Copolymer). A preferred material is SBC - KR03-Resin from Styrosolution. Some examples of materials for the handle connecting structure are PPA Polyphthalamide)/PPS (Polyphenylene sulphide)/LCP (Liquid Crystal Polymer). The material may have a glass filling of 0% up to 40%, or 10% to 30%, preferably around 20%. The materials and/or fabrication process may be chosen in such a way that the insert and core material will chemically bond with the handle material.
[0135] Measures may be taken to enhance the friction properties of the handle body, particularly to improve “wet grip”. To combine desired features such as transparency, softness and manufacturability, certain materials are chosen. When used in a wet environment during shaving, e.g. combined with soap, these materials may result in a very slippery feeling for the user. Significant improvements in wet grip may be achieved with the methods set out below (separately or in combination) whilst retaining (at least to a great extent) desirable initial properties of the material in terms of soft feeling and transparency.
[0136] By applying a rough texture to the outside of the handle, the wet grip can be improved. When there is no texture or a very fine texture, a thin layer of water can form between the handle and the human skin, the water cannot drain properly and therefore acts as a lubricant resulting in poor wet grip. If a rougher texture (RA, average roughness, estimated between 80 to 400 .Math.m) is applied (based on the same design principle as the indentations in tires) the water can drain through the depressions/slots formed by the texture while the elevations/bumps (rubber islands in the tires) keep contact with the human skin.
[0137] Fine texturing can be hydrophobic and is a good alternative to rough texturing. Water droplets on a smooth surface will form an almost hemispherical shape. A surface given a fine (e.g. nano or pico) structure will form water droplets of increased height which are closer to spherical in shape. As a result the water will roll off the handle more easily and is less likely to form a thin layer of water which could give a slippery effect when gripped.
[0138] Wet friction may be increased with additives. For example, micro beads, with a maximum particle size in the tens or hundreds of microns may be suitable to increase friction. Other suitable additives may be petrolatum, polybutene, polyisobutylene or microcrystalline wax, or the like. The additives may be hydrophobic or oleophobic or work by another mechanism. Example commercially available additives are Styroflex (Ineos) or similar, Hybrar (Kuraray) or similar, Kraton FG 1901, organomodified siloxanes or any combination thereof.
[0139] Fluorising may also improve wet grip. In this process, the outer layer is treated with fluorine. Exposure to a fluorine mixture (for example gas-phase fluorising) allows replacement of some of the hydrogen atoms in the surface of the coating with fluorine.
[0140] Surface coatings may be of a softer plastic, harder plastic or other type of film. A friction-enhancing surface coating in the form of a lacquer is a particularly suitable measure. Such a lacquer can additionally improve other properties, such as visual or haptic properties (to give colour, texture, glossy effects or various tactile experiences, visual effects (pearlescence, metallic, splattered paint, etc.) or use properties (protection against any of UV radiation, chemical attack and mechanical rupture). In one embodiment, the wet grip of the handle is improved by applying a thin layer of colorless lacquer with improved wet friction properties. This lacquer can provide a very nice silky texture and tactility. The lacquer can consist of a single or multi component grade and may or may not require a primer to improve adhesion to the substrate. Small particles or other additives can also be added to the lacquer to improve grip. The thickness of the lacquer can vary between 20 and 250 .Math.m, and is most likely to be around 50 .Math.m.
[0141] One suitable lacquer is a polyester based 2 component soft paint lacquer, such as Pehapol 2C soft paint P84004 by Peter Lacke or HARD 000033 by Nordwest Chemie. It is applied by spray painting. The volatile component evaporates.
[0142] The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present invention as contemplated by the inventor(s), and thus, are not intended to limit the present invention and the appended claims in any way.
[0143] The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
TABLE-US-00001 Reference numbers 10 cartridge 12 lubrapad 14 blade housing 16 blades 18 guard 20 cap 22 lubrapad body 26 frame 42 rounded side portions (of the cartridge) 50 handle body 51 front surface portion or opposite end surface 52 rear surface portion or flat end surface 53 underneath surface portion 54 top surface portion 55 lateral surface portion 56 continuous side surface 57 handle attachment portion 58 handle body recess 59 handle connecting structure 61 cartridge connecting structure 70 outer layer 80 core layer 81 first core sublayer 82 second core sublayer 83 third core sublayer 84 forth core sublayer 100 safety razor or safety razor system 161 core material inlet 162 outer material inlet 163 rotating hub or core 164 moulding cavity 165 ejection chute 200 protective cover