SAFETY RAZORS

Abstract: A razor including an elongated handle (6) and a blade unit (1) at one end thereof and extending transversely thereto. The blade unit (1) is flexibly mounted on the handle (6) and is anchored toward each end to permit the centre region to bow inwardly and outwardly.

Description: This invention relates to safety razors of the known form comprising a flexible razor blade unit secured to a handle by connecting means arranged to permit free flexure of the unit in use of the razor. The blade unit is flexible in the sense that it is readily flexible, in response to forces encountered during normal use, about an axis or axes parallel with the plane of the blade (or blades) and extending substantially perpendicular to the cutting edge (or edges) thereof. The present invention is particularly concerned with the means by which such a unit is connected to a razor handle so as to be adequately supported and guided thereon whilst permitting the required flexure of the unit in use. For convenience of description, the blade unit will be assumed to be a tandem blade unit, having a pair of parallel blades whose respective cutting edges are held in spaced parallel relation, so as to act in tandem on the skin of the user. U.S. Patent 4,409,735 is concerned with a flexible blade assembly wherein the flexing of the blade assembly is made possible by the provision of two sliding pin connectors allowing small motions parallel to the blade edge, but does not suggest any form of reliable mounting for attachment to a handle. According to the present invention there is provided a safety razor including a razor blade unit having at least one blade and a handle, said blade unit being readily flexible, in response to forces encountered during normal use, about an axis or axes parallel with the plane of said blade and extending substantially perpendicular to the cutting edge of the blade, characterized in that the blade unit is connectable to the handle by a slide for mounting and guiding the unit for reciprocal movement relative to the handle in a direction substantially perpendicular to the plane of the blade, said slide being located at the mid-length of the unit, and in that further connections are provided on either side of the slide, to permit relative movement of opposite end portions of the blade unit, relative to the handle, in directions generally parallel to the blade edge. With this arrangement, the slide means serve to centralise the unit longitudinally on the handle, whilst permitting free movement of the central part of the unit towards and away from the handle and the further connections, which are conveniently formed as pin and slot connections permit concomitant movement of the opposite end portions of the unit towards and away from each other. This form of the invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view, from below of the handle and blade unit, both partly broken away, prior to assembly; Fig. 2 is a perspective view from below the handle assembled with the unit, which is shown in phantom line; Fig. 3 is a cross-section of the assembled razor; and Fig. 4 is a scrap rear view of the assembled razor. The illustrated razor comprises a flexible head or blade unit 1 including a tandem pair of wafer thin, single edged blades 2 separated by a spacer and set permanently in a highly flexible moulded plastics support structure 3 providing a comb-like skin guard 4 ahead of and below the blade edges and a segmented cap portion 5 overlying the blade pair. The razor handle is constituted by a unitary moulding of plastics material formed to provide an elongate grip portion 6 and a generally plate-like upper portion 7 on which the blade unit 1 is mounted. The connection means include a slide means comprising a central post 10 of rectangular cross-section which depends from the underside of the blade unit and extends substantially perpendicular to the planes of the blades at the mid-length of the blade unit, and a pocket 11 formed at the upper end of the handle. The pocket is also of rectangular cross-section and is sized to receive the post 10 with an easy sliding fit. With the post located in the pocket, the blade unit is centralized longitudinally relative to the handle and restrained from rotating about the handle, but is guided for easy sliding movement towards and away from the handle, in the direction of the length of the post 10. Further connections are made to either side of the central post 10 which permit and constrain the opposite end portions of the unit to move, relative to the handle, towards and away from each other, generally parallel to the blade edges. The handle upper portion 7 is formed with respective support legs 12 each terminating at a forwardly projecting pin 13 of part rounded cross-section. In the assembled razor, the pins 13 are located in and trapped by rearwardly facing pockets 14 formed at the underside of the support structure 3. The pockets 14 are conveniently formed between adjacent ribs 15 of the structure 3 and short bridging portions 16 interconnecting the said ribs. As best seen in Fig. 4, the depth of each pocket approximates to the depth of the corresponding pin 13, whose upper and lower rounded edges are located against the upper and lower faces of the pocket. The width of the pocket is, however, greater than that of the pin so as to permit movement of the pocket relative to the pin in a direction generally parallel to the blade edges. Engagement of the pins in the pockets also retains the blade unit against removal from the handle. The upper rounded edges of the legs 12 and pins 13 engage against the underside of webs 17 spanning adjacent ribs 15. Initial assembly of the unit with the handle is readily effected by engaging the centre post 10 in the guide pocket 11 and pressing the unit towards the handle in the regions of the legs 12, the pins 13 snapping into the pockets 14, thanks to the flexibility and resilience of the components. The illustrated razor is intended to be disposable, but the connection means illustrated may readily be modified to cater for removal and replacement of the blade units on a permanent handle. The unit is thus securely retained to the handle by connection means of very simple construction, but retains its high degree of flexibility, reduced only by the very small frictional resistances to sliding between the components. The support legs 12 are each set in from the ends of the blade unit, their spacing apart being approximately 2/3 of the length of the unit, so as to permit the unit to deflect convexly if one or both ends encounter larger forces in use than the medial section. The unit can, of course, deflect concavely if more force is encountered in the medial section. In the concave mode, deflection is limited by abutment of the underside of the blade unit with the upper end of the central portion of the handle, and in the convex mode by the underside of the cartridge abutting the upper edges 18 of the outer ends of the portion 7. In the particular embodiment illustrated, concave deflection is limited to 2.5 mm at the centre, and in the convex mode, deflection of the end portions of the unit is limited to 3 mm, both measured from the neutral, unstressed condition of the unit. The main forces encountered during shaving are directed perpendicular to the planes of the blades, and pass through a region bordered by the cutting edges of the blades. For this reason, the post 10 is aligned with that region, so as to minimise any tendency for the post 10 to be subjected to any bending movements which would tend to cause it to bind in its pocket 11. In the case of a single blade unit, the post is aligned with the cutting edge of the blade.

Claims: A safety razor including a razor blade unit (1) having at least one blade (2) and a handle (6), said blade unit (1) being readily flexible, in response to forces encountered during normal use, about an axis or axes parallel with the plane of said blade (2) and extending substantially perpendicular to the cutting edge of the blade, characterized in that the blade unit (1) is connectable to the handle (6) by a slide (10, 11) for mounting and guiding the unit for reciprocal movement relative to the handle (6) in a direction substantially perpendicular to the plane of the blade (2), said slide being located at the mid-length of the unit, and in that further connections (12, 13, 14) are provided on either side of the slide (10, 11), to permit relative movement of opposite end portions of the blade unit, relative to the handle, in directions generally parallel to the blade edge. A razor according to claim 1, characterized in that the slide is a post (10) extending essentially perpendicular to said plane and a socket (11) within the handle in which the post is slidably engaged. A razor according to claim 2, characterized in that the post (10) and the socket (11) are both of non-circular cross-section to prevent relative rotation therebetween. A razor according to claim 2 or claim 3, characterized in that the post (10) is aligned with a central region of the unit in which the main forces encountered during shaving are directed. A razor according to any one of claims 1 to 4, characterized in that the further connections each comprise a pin (13) engaging in a pocket (14) with freedom to slide laterally therein, in directions generally parallel with the blade edge, but constrained against substantial relative movement in directions perpendicular to the plane of the blade. A razor according to claim 5, characterized in that the pins (13) extend parallel with the said axis or axes and have rounded upper and lower edges to facilitate flexure of the unit about the said axis or axes. A razor according to claim 6, characterized in that the pins (13) are fast with the razor handle (6) and engage in pockets (14) formed in the blade unit (1). A razor according to any preceding claim, characterized in that the further connections are each set in from the ends of the unit and are spaced apart by a distance approximately two-thirds of the length of the blade unit.

Inventors: OLDROYD, BRIAN
Applicants: THE GILLETTE COMPANY
Application year: 1988
Main classification: B26B21
IPC codes: B26B21