Patent Application
20080196251
This invention is concerned with safety razors, also called wet razors, that are capable of conforming to the shape of a surface being shaved.
There are known wet safety razors that are intended to provide a degree of conformance to skin curvatures. Such a safety razor is disclosed in U.S. Pat. No. 7,024,776 (Wain) and a blade suitable for use therein is disclosed in U.S. Pat. No. 6,804,886 (Wain). In WO 99/04938 (Hawes et al) a flexible support for a substantially rigid shaving cartridge is described and includes a pair of arms extending from a handle and a strut interconnecting the free ends of the arms. Flexible safety razor blade units or cartridges are also know, for example from WO 92/06828 (Oldroyd) and GB 2 119 690 (Motta et al). In our pending British Patent Application No. 0615113.8, filed on 28 Jul. 2006 (internal Dkt. Z-04687), there is proposed a safety razor assembly including one or more elongate flexible blades supported by a structure that is deformable for following concave or convex curvatures, the supporting structure including two suspension members each comprising a multiplicity of elongate support elements interconnected by hinges at lower ends and having sliding cooperation with the blade structure at upper ends.
The present invention sets out to provide a simple support structure for a flexible blade assembly that provides effective support and control of the blade assembly whilst allowing the blade assembly to flex in order to follow convex and concave skin curvatures.
Provided in accordance with the invention is a support structure for a razor blade assembly comprising a guard structure, a cap structure and one or more blades, the blade assembly having opposed ends and being flexible between the ends, the support structure comprising a subframe, end mounts on which the opposed ends of the blade assembly are carried, the end mounts being coupled to the subframe by suspension arm structures to allow tilting of the end mounts relative to the subframe to permit concave and convex flexing of the blade assembly, and a stop arrangement for at least limiting longitudinal displacement of the blade assembly relative to the subframe.
The invention also includes a safety razor equipped with a support structure as defined above, and a shaving cartridge incorporating a support structure according to the invention as defined above.
The blade assembly preferably includes a plurality of blades, e.g. 2, 3, 4, 5 or possibly even more blades. Conveniently the blades are of the type described in U.S. Pat. No. 6,804,886 B2 (Wain) the entire disclosure of which is hereby incorporated herein by reference. Another alternative within the scope of the invention is a blade comprising a flexible plate or sheet with a number of through holes, e.g. circular holes which have cutting edges extending at least partially around their peripheries. In the embodiments particularly described hereinbelow, the blade assembly includes several elongate parallel blades carried on a flexible frame structure having end portions that are firmly fastened to the respective end mounts of the support structure. The frame structure may be formed as a moulding of elastromeric material and the blades may be secured onto the frame in any suitable manner, such as by overclips wrapped around the frame structure to capture the ends of the blades, as known per se. Alternatively the frame structure may be provided with an arrangement of seats or clips for holding the blades on the frame structure. The blade clips or seats can comprise slots to receive the blades and can be configured to orientate planar blades in inclined dispositions with their cutting edges uppermost. As another alternative the blades can be fastened, such as by welding to underlying frame elements. The sub-assembly of blades and frame elements can be moulded into or otherwise fixed to a frame structure of an elastomeric material.
The guard structure may be constituted by a leading edge portion of the frame structure. Another possibility is for a separate guard member to be attached to the frame structure, for example a guard member of elastometric material that could be moulded in situ onto the frame structure. Preferably the guard structure is formed in one piece and extends continuously along the forward edge of the blade assembly.
The cap structure can include a skin contacting member, such as a strip containing an agent, e.g. a lubricating agent, for application to the skin during shaving. The skin contacting member may additionally or alternatively constitute a source of other shaving enhancement products known per se. Conveniently the skin contacting member comprises a series of segments, either linked together or entirely separate from each other, disposed along a trailing edge portion of the blade assembly. The segments of the skin contacting member may be moulded in situ onto the frame structure.
With a flexible blade assembly carried on a supporting structure in accordance with the invention forces applied to the blade assembly, in the downward direction generally towards the subframe, in a region medially between the ends of the blade assembly will result in the blade assembly deforming to a concave configuration, the end mounts of the support structure tilting upwardly to guide and control the ends of the blade assembly to ensure a smooth curvature along the length of the blades of the blade assembly. Similarly, relatively high downwardly directed forces applied in the region of at least one end of the blade assembly cause the blade assembly to take up a convex curvature along its length with the end mounts tilting downwardly and again ensuring a smooth curvature along the length of the blade assembly. The stop arrangement of the support structure may be configured to substantially preclude longitudinal displacement of the blade assembly, and hence the blades, relative to the subframe and a razor handle. Thus, the stop arrangement may comprise a restraining device that prevents displacement of the blade assembly of the blades in a lengthwise direction. However, a limited amount of longitudinal displacement may be permitted without creating potential risk to a razor user and can be beneficial in facilitating flexing of the blade assembly to conform to skin contours during shaving. In the latter case the stop arrangement can comprise limit stops, e.g. to restrict the deformation of the suspension arm structures. The resilience of the blade assembly can be relied upon to return the blade assembly to a normal straight configuration when it is relieved of any external forces imparted thereon and causing it to deflect from that straight configuration.
In a convenient construction which facilitates mounting of the blade assembly onto the support structure, the end mounts define platforms to which the blade assembly can be easily attached such as by welding, riveting, gluing or the like.
The suspension arm structures can each include two hingedly interconnected arms coupled between the respective end mount and the subframe. More particularly each suspension arm structure may comprise inner and outer arms with the end mounts being disposed at first ends of the outer arms. A second end of the outer arm can be hingedly connected to the first end of the inner arm so that the two arms generally form a V-shape. The second end of the inner arm can be hingedly connected to the subframe. Thus, the inner and outer arms of each suspension arm structure can be connected together by first pivotal connections therebetween, and the inner arms can be connected to the subframe by second pivotal connections. The first and second pivotal connections can each consist of a pivot joint or a living hinge, and in either case the pivotal connections can incorporate limit stops for limiting the range of deformation of the suspension arm structures, and thereby also the longitudinal displacement of the blade assembly with respect to the subframe. The first ends of the outer arms can be upper ends. The second end of the outer arm can be a lower end. The first end of the inner arm can be a lower end, and the second end of the inner arm can be an upper end.
A restraining device that prevents longitudinal movements of the blade assembly relative to the subframe can be arranged between a medial portion of the blade assembly and the support structure for guiding the medial portion of the blade assembly for movement in a direction towards and away from the subframe. For this purpose the restraining device may comprise an elongate member arranged between the blade assembly and the subframe. The elongate member, for example a pin connected to the underside of the cap structure, can have sliding cooperation with the subframe, such as by being arranged to extend through a guide slot formed in the subframe. In an alternative construction the restraining device comprises a torsion bar. The torsion bar is connected at one end to one of the end mounts of the support structure, and at the other end is coupled to the subframe, conveniently at a pivotal connection between the subframe and the suspension arm structure carrying the other end mount.
The foregoing and other advantageous features of the preferred embodiments of this invention will become apparent from the detailed description which follows, reference being made to the accompanying drawings.
Throughout the drawings and the description which follows the same reference numerals have been used to designate corresponding parts and components in the respective embodiments and unless otherwise indicated the description of any part given with respect to one embodiment will apply equally to corresponding parts of other embodiments designated with the same reference numerals.
The blade assemblies and their support structures illustrated in the drawings are in use mounted on razor handles, either permanently with the intention that the entire razor should be discarded when the sharpness of the blades has reduced to an unsatisfactory level, or replaceably so that a used blade assembly can be replaced with a fresh blade assembly with sharp blades. If desired the blade assembly and its support structure can be pivotably mounted with respect to the handle in a manner well known per se, and the support assembly can be biased to a rest position with respect to the handle by a sprung plunger provided in the handle and arranged to act on a cam face formed on the subframe also in a manner known per se. The attachment of the support structure to the handle, may be direct or through the intermediary of a connecting part. The connection to the handle itself is ancillary to the present invention, for which purpose any suitable connection structure can be employed and will not be described further.
Illustrated in
The blade assembly 2 is mounted on the support structure 3 which has a substantially rigid subframe 15 disposed beneath the blade assembly, and respective suspension arm structures 16 connecting end mounts 17 for the blade assembly to the ends of the subframe. In the exemplary embodiments illustrated in the drawings the end mounts 17 define support platforms for the end parts 7, 8 of the frame structure. The end parts 7, 8 of the frame structure of the blade assembly are fixedly attached to the respective end mounts 17 so that the end parts 7, 8 and the end mounts are constrained to move together during flexing of the blade assembly. Each suspension arm structure 16 includes an outer arm 20 to a first, or upper end as shown, of which the end mount 17 is fixed, and a lower second end of which is hinged by a first pivotal connection 21 to a lower first end of an inner arm 22, shown formed by a plate-like strut, and having its upper second end coupled to the subframe 15 by a second pivotal connection 23, the axes of the first and second pivotal connections 21, 23 being parallel. The suspension arm structures 16 support and guide the end mounts 17 for tilting by performing, for example, swinging movements along arcuate paths i.e. a curvilinear motion, to permit concave and convex flexing of the blade assembly. A stop arrangement is provided to limit or prevent longitudinal displacement of the blade assembly 2 with respect to the subframe 15, and relative to a razor handle (not shown) coupled in use to the subframe. The stop arrangement in the embodiment of
For attaching the blade unit 1 of
Shown in
As in the blade unit of
It is not essential for pivot joints to be employed at the connections 21, 23 between the inner arms 22, of the suspension arm structures 16 and the subframe 15, or between the inner arms 22 and the outer arms 20. Shown in
Illustrated in
It should be understood that the foregoing description of the preferred embodiments is given by way of non-limiting example only and that modification and variations are possible without departing from the scope of the invention as defined by the claims which follow. In addition, features described in relation to specific embodiments can be included in other embodiments. Other arrangements for guiding the medial portion of the blade assembly to move towards and away from the subframe besides the pin and slot arrangement of
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention. To the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
