Patent Description:
Many modern wet shaving razors, also known as safety razors, typically comprise a handle and a razor cartridge mounted to the handle. Some razors are so-called disposable razors wherein the handle and razor cartridge together are disposed of after use. Other razors may be in the form of a so-called system that comprises a handle that can be reused and a removable razor cartridge that is disposed of after use and can be replaced with a new cartridge. <CIT> discloses an exemplary system razor handle including several component parts that in combination comprise a mechanism to secure and eject a cartridge connector (with its blade unit) of a razor cartridge upon actuation of a release button by a user.

A further type of safety razor is a so-called semi-disposable razor. A simplified handle (in comparison to that in e.g. '<NUM> above), that can be a single component part is provided to a user, together with a small number of replaceable cartridges as a packaged unit, e.g. one handle and five cartridges. The handle is intended to survive a limited number of uses with the supplied cartridges. This combination provides the convenience of a disposable razor but requires less resources, e.g. "less plastic" in comparison to e.g. <NUM> complete disposable razors. <CIT> discloses an exemplary semi-disposable razor. The handle of this document has attachment structure for the cartridge comprising three prongs, the center of which bears a tooth that snap-fittingly engages the cartridge. The handle of '<NUM> therefore inherently requires certain physical properties, e.g. at least a certain flexural modulus and permissible strain for its center prong to function as disclosed, at least over a requisite limited number of cycles.

Prior art document <CIT> discloses the preamble of independent claim <NUM>.

The present disclosure has for its objective to substantially alleviate the limitations of the prior art razors by providing a safety razor, and a connector and a handle for the same. A safety razor is provided comprising a blade unit having a housing with a razor blade and an elongated handle. The handle has a uniform thickness, preferably <NUM>, and has a first end including an aperture extending into the thickness, and an opposed second end. A connector connects the blade unit to the handle. The connector has a body with a first arm and a second arm both extending from the body, respective distal end regions of both arms being adapted to connect the blade unit to the handle. The body has a recess having an opening and a user-operable latch including a protrusion at a first end of the latch, the protrusion extending into the recess. The first end of the handle is removably received in the recess and the protrusion is received in the aperture to secure the connector to the handle, and the protrusion is releasable from the aperture by a user-applied force (F) to a lever at a second end of the latch opposite the first end to release the first end of the handle from the recess.

In some aspects the handle has a curved profile in an orientation perpendicular to the thickness. In some aspects the handle is flat in transverse cross section. In other aspects the handle is not flat, e.g. having a gentle curve in transverse cross section. In some aspects the aperture in the first end of the handle is bounded. In some aspects the aperture in the first end of the handle extends through the first end.

In some aspects the first end of the handle, in combination with the recess of the connector define a poka yoke feature to prevent an incorrect orientation of the handle in the connector. The poka yoke feature can include a first outer corner radius and a second outer corner radius, each outer corner radius being at the first end of the handle, and the first outer corner radius is different than the second outer corner radius, preferably the first outer corner radius has a magnitude three times the magnitude of the second outer corner radius.

In some aspects the handle comprises a plant-based, non-polymeric material, preferably one of wood-based and grass-based, more preferably bamboo. In some aspects the plant-based, non-polymeric material defines a fiber direction. In some aspects the handle comprises a single layer of plant-based non-polymeric material. In other aspects the handle comprises between two and nine layers of plant-based non-polymeric material, preferably three layers of plant-based non-polymeric material. In some aspects of the preceding aspect the fiber direction of any one layer is arranged at an angle to the fiber direction of the next adjacent layer, preferably arranged perpendicularly to the fiber direction of next adjacent layer.

In some aspects the handle comprises only a single component part.

In some aspects the user-operable latch is supported in the body by a torsion beam spring integrally formed between the body and the latch.

In some aspects the connector comprises one of a biopolymer, preferably medium chain polyhydroxyalkanoate (PHA), and mixture of medium chain polyhydroxyalkanoate (PHA) and a plant-based non-polymeric material.

In some aspects of the present disclosure, which are not part of the claimed invention, a connector adapted to removably connect a handle to a blade unit is provided. The connector has a body with a first arm and a second arm both extending from the body, respective distal end regions of both arms are adapted to connect the blade unit to the connector. The body has a recess having an opening, and a user-operable latch including a protrusion at a first end of the latch extending into the recess, the recess is adapted to removably receive the first end of the handle, and the protrusion is received in an aperture at the first end, the protrusion being releasable from the aperture by a user-applied force (F) to a lever at a second end of the latch opposite the first end, to release the first end of the handle from the recess.

In some aspects the recess of the connector in combination with the first end of the handle, define a poka yoke feature to prevent an incorrect orientation of the handle when received in the connector. The poka yoke feature can include a first inner corner radius and a second inner corner radius, each inner corner radius being at an end of the recess opposed the opening, and the first inner corner radius is different than the second inner corner radius, preferably the first inner corner radius has a magnitude three times the magnitude of the second inner corner radius. A wall bounding the recess can be provided with a window opening permitting a user to view the inner corner radii.

In some aspects the user-operable latch includes a second end opposite the first end and has a lever, and the torsion beam spring is formed with the latch in a region between the first end and the second end.

In some aspects the connector comprises one of a biopolymer, preferably medium chain polyhydroxyalkanoate (PHA), and mixture of medium chain polyhydroxyalkanoate (PHA) and a plant-based non-polymeric material. In other aspects the connector can comprise a thermoplastic polymer, i.e. a petroleum based material.

In some aspects of the present disclosure, which are not part of the claimed invention, a handle for a safety razor is provided. The handle comprises an elongated slat having a uniform thickness, preferably <NUM>, and having a first end including an aperture extending into the thickness, and an opposed second end. The handle can comprise a plant-based, non-polymeric material that defines a fiber direction, the material being preferably one of wood-based and grass-based, more preferably bamboo.

In some aspects the first end of the handle, in combination with a recess of a connector for the safety razor define a poka yoke feature to prevent an incorrect orientation of the handle in the connector. The poka yoke feature can include a first outer corner radius and a second outer corner radius, each outer corner radius being at the first end of the handle, and the first outer corner radius is different than the second outer corner radius, preferably the first outer corner radius has a magnitude three times the magnitude of the second outer corner radius.

In some aspects the handle comprises a single layer of plant-based non-polymeric material. In other aspects the handle comprises between two and nine layers of plant-based non-polymeric material, preferably three layers of plant-based non-polymeric material. In some aspects of the preceding aspect the fiber direction of any one layer is arranged at an angle to the fiber direction of the next adjacent layer, preferably arranged perpendicularly to the fiber direction of the next adjacent layer.

In some aspects the handle comprises only the slat, and the slat is a single component part.

According to the foregoing, a safety razor that can be in the form of a semi-disposable razor is less dependent upon its handle having physical properties at least inherently considered necessary requirements in the prior art. The safety razor can employ "sustainable" and plastics-free materials, especially for its handle.

The above features and advantages will be more fully understood with reference to the following detailed description when taken in conjunction with the accompanying drawings.

Referring now to the drawings, and in particular <FIG>, a safety razor <NUM> is depicted. The safety razor <NUM> comprises a blade unit <NUM> having a housing <NUM> with a razor blade <NUM>, an elongated handle <NUM> and a connector <NUM> connecting the blade unit <NUM> to the handle <NUM>. The materials and construction of a blade unit <NUM> containing one or several blades <NUM> will be well known to the skilled worker and will not require further discussion.

Referring additionally to <FIG>, a connector <NUM> is depicted. The connector <NUM> has a body <NUM> with a first arm <NUM> and a second arm <NUM>, both extending from the body <NUM>. Respective distal end regions 80a, 82a of both arms <NUM>, <NUM> are adapted to connect the blade unit <NUM> to the connector <NUM>. The distal end regions 80a, 82a can for example be provided with suitable structures, e.g. shell bearing structures to pivotally connect the blade unit <NUM> to the connector <NUM>. The body has a recess <NUM> with an opening <NUM>. The body <NUM> also has a user-operable latch <NUM>. The latch <NUM> has a first end <NUM> and a second end <NUM>. The first end <NUM> of the latch <NUM> has a protrusion <NUM> that extends into the recess <NUM>. The second end <NUM> of the latch <NUM> has a lever <NUM> whereby a user can apply a suitable force F to operate the latch <NUM>. The latch <NUM> is supported in the body <NUM> by integrally formed torsion beam springs <NUM>, formed with the latch <NUM> in a region between the first end <NUM> and the second end <NUM>.

The connector <NUM> is preferably manufactured by injection molding. A preferred material is a biopolymer or a mixture of a biopolymer and a particulate plant-based non-polymeric material, e.g. <NUM>% biopolymer / <NUM>% plant material. A preferred biopolymer is medium chain polyhydroxyalkanoate (PHA). Medium chain PHA is preferred over short chain PHA for benefits of toughness and resiliency, compared to short chain polymers that can be hard but brittle. The connector <NUM> can be formed from a polymer that is not a bio-material. This is less preferable for "sustainability" reasons but such a material can provide cromulent performance. Suitable polymers include polyoxymethylene (POM, also known as acetal), polyamide (e.g. PA6 or PA6. <NUM>) and acrylonitrile butadiene styrene (ABS), and mixtures of suitable materials.

Referring now to <FIG>, a handle <NUM> is depicted. The handle <NUM> is elongated and has a first end <NUM> and a second end <NUM>. The handle <NUM> preferably comprises a slat <NUM>, being a single component part. The handle <NUM> has a thickness <NUM> that is preferably uniform (see especially <FIG>). The handle <NUM> preferably has a curved profile when viewed in an orientation perpendicular to the thickness <NUM> (see <FIG>). The curved profile can provide ergonomic (haptic) advantages for the user, e.g. presenting the cartridge <NUM> at an habitual orientation for use relative to the user's habitual grip position. The handle <NUM> can also be straight (see <FIG>). The first end <NUM> has an aperture <NUM>. The aperture <NUM> preferably extends through the first end <NUM> but can extend part-way into the first end (see <FIG>) such that the walls bounding the aperture <NUM> provide adequate engagement with the protrusion <NUM> of the connector <NUM> (see <FIG>). The aperture <NUM> is preferably fully bounded (i.e. the bounding walls extend fully around the aperture <NUM>) or can be partially bounded (see <FIG>).

The handle <NUM> comprises a plant-based non-polymeric material, e.g. a wood-based or a grass-based material, the material defining a fiber direction <NUM>. Another suitable material is a compressed leaf mass, e.g. palm leaves. A preferred material is bamboo (a type of grass). A preferred wood is birch but other woods such as the giant redwood, the larch, the fir and the mighty Scots pine are suitable. The handle <NUM> preferably comprises a single layer <NUM> of plant-based non-polymeric material (see <FIG>). The handle <NUM> can equally preferably comprise a laminated (e.g. "plywood") structure of multiple (e.g. <NUM> to <NUM> but preferably <NUM>) (sub-)layers <NUM> (see <FIG>). (Sub-)layers <NUM> can be suitably bonded together in processes that will be well known to the skilled worker. In embodiments having multiple (sub-)layers <NUM>, the fiber direction <NUM> of adjacent layers can be arranged angularly displaced. In <FIG> a fiber direction 54e of a layer <NUM> can be aligned with the length of the handle <NUM> with a next adjacent layer's fiber direction 54t arranged transversely thereto. A fiber direction 54x can be angled, e.g. at <NUM> degrees, to the length of the handle <NUM> with a next adjacent layer's fiber direction 54x opposedly arranged.

The thickness <NUM> of the handle is preferably <NUM> but other thicknesses can be suitable and the present disclosure should not be limited thereto. In one preferred execution the thickness <NUM> can be provided by a three-layer <NUM> laminate of bamboo. The central (sub-) layer <NUM> has a fiber direction 54e aligned with the length of the handle <NUM> and the (next adjacent) outer layers <NUM> have fiber directions 54t transverse to the central layer <NUM>. In another preferred execution the handle <NUM> comprises a single layer <NUM> of birch, having a fiber direction 54e aligned with the length of the handle <NUM>.

The handle <NUM> can be manufactured by providing a sheet of plant-based non-polymeric material having a suitable thickness <NUM> and stamping (perforating) a suitable flat form. In executions having a curved profile, the profile can be provided by suitable heat, or heat and humidity processes (e.g. steam forming). Such processes will be well known to the skilled worker. The handle is preferably flat in transverse cross section (see <FIG>) but can be non-flat, e.g. having a gentle curve across its transverse width. Such a non-flat transverse shape can be resultant from a process to provide the curved profile.

One purpose of the disclosed safety razor <NUM> is a semi-disposable razor whereby a single handle <NUM> can be packaged with a number (e.g. <NUM>) of replacement cartridges (each comprising a blade unit <NUM> connected to a connector <NUM>) such that a user can selectively replace the cartridge. In embodiments where the handle <NUM> has a curved profile it is desirable that the user correctly orients the handle <NUM> relative to the connector <NUM>. To assist avoiding user mistakes, the handle <NUM> in combination with the connector <NUM> is provided with a poka-yoke feature <NUM>. Poka-yoke is a Japanese term that is adopted in English language dictionaries, that means "mistake-proofing" or "inadvertent error prevention. " The first end <NUM> of the handle <NUM> can be provided with a first outer corner radius <NUM> and a second outer corner radius <NUM>. The corner radii <NUM>, <NUM> are sized to be obviously different to a user. For example, the first outer corner radius <NUM> can be <NUM>, having a magnitude three times that of the second outer corner <NUM> radius that can be <NUM>. The end of the recess <NUM> opposed the opening <NUM> of the connector <NUM> is provided with respective complementary first and second inner corner radii <NUM>, <NUM>. To assist user recognition of a correct or incorrect orientation of the first end <NUM> of the handle <NUM> in the recess <NUM> of the connector <NUM> a wall bounding the recess <NUM> can be provided with a window opening <NUM> permitting a user to view the inner corner radii <NUM>, <NUM> and thus how the outer corner radii <NUM>, <NUM> are correctly or incorrectly engaging inner corner radii <NUM>, <NUM>. If, for example, a user attempts to insert the first end <NUM> into the recess in an incorrect orientation, the smaller outer corner radius <NUM> will contact the larger inner corner radius <NUM> before the first end <NUM> is completely inserted in the recess <NUM>. Latch protrusion <NUM> will not engage aperture <NUM> and the handle <NUM> will not be correctly retained in the connector <NUM>. <FIG> is a detailed portion of a sectional view of a connector <NUM> correctly connected to a handle <NUM>, showing latch protrusion <NUM> engaged in aperture <NUM>. To disconnect the cartridge from the handle <NUM>, a user can apply a suitable force F to the lever <NUM> at the second end <NUM> of the latch <NUM>. The latch rotates about torsion beam springs <NUM> (not seen in this Fig., see e.g. <FIG>) to disengage protrusion <NUM> from aperture <NUM> thus allowing the handle <NUM> to be withdrawn from the connector <NUM>.

Claim 1:
A safety razor (<NUM>), comprising:
a blade unit (<NUM>) having a housing (<NUM>) with a razor blade (<NUM>);
an elongated handle (<NUM>) having a uniform thickness (<NUM>), preferably <NUM>, and having a first end (<NUM>) including an aperture (<NUM>) extending into the thickness (<NUM>), and an opposed second end (<NUM>); and
a connector (<NUM>) having a body (<NUM>) with a first arm (<NUM>) and a second arm (<NUM>) both extending from the body (<NUM>), respective distal end regions (80a, 82a) of both arms (<NUM>, <NUM>) being adapted to connect the blade unit (<NUM>) to the handle (<NUM>); the body (<NUM>) having a recess (<NUM>) having an opening (<NUM>), characterised by the body (<NUM>) of the connector (<NUM>) having a user-operable latch (<NUM>) including a protrusion (<NUM>) at a first end (<NUM>) of the latch (<NUM>), the protrusion (<NUM>) extending into the recess (<NUM>), the first end (<NUM>) of the handle (<NUM>) being removably received in the recess (<NUM>) and the protrusion (<NUM>) being received in the aperture (<NUM>) to secure the connector (<NUM>) to the handle (<NUM>), and the protrusion (<NUM>) being releasable from the aperture (<NUM>) by a user-applied force (F) to a lever (<NUM>) at a second end (<NUM>) of the latch (<NUM>) opposite the first end (<NUM>) to release the first end (<NUM>) of the handle (<NUM>) from the recess (<NUM>).