CA2242529C

CA2242529C - Safety razors

Info

Publication number: CA2242529C
Application number: CA002242529A
Authority: CA
Inventors: Thomas A. Christman; Christopher Martin Hawes
Original assignee: Gillette Co LLC
Current assignee: Gillette Co LLC
Priority date: 1996-01-16
Filing date: 1997-01-16
Publication date: 2002-05-07
Anticipated expiration: 2017-01-16
Also published as: BR9707293A; EP0960004B1; KR100523008B1; ATE202307T1; CZ224898A3; CN1116967C; JP3980060B2; KR19990077210A; PL182457B1; WO1997026119A1; CA2242529A1; JP2000503222A; DE69705326T2; EP0960004A1; RU2171174C2; DE69705326D1; CN1212647A; AU722992B2; CZ290857B6; PL327852A1

Abstract

In a safety razor, a blade assembly (2; 22; 52) is mounted to a handle by a mounting arrangement including several spring devices (8; 28; 68; 70) adapted so that the blade assembly is movable relative to the handle with several degrees of freedom, including pivotal movement about a longitudinal axis, pivotal movement about a transverse axis and translational movement in a downward direction substantially perpendicular to the plane defined by these axes. The longitudinal and transverse pivotal axes are not fixed in position and are variably located due to the spring suspension, allowing the blade assembly to follow closely the contours of a skin area being shaved.

Description

-SAFEl[Y RAZORS

This invention relates to safety r~ors and is particularly concerned with safety razors of a form including a handle and a blade ~ssPmbly mounted to the handle by an arr~n~ement pe. ",i~l;..g movement of the blade assembly relative to the handle. In tlhe embo(limentc of the invention describedherein the blade assembly includes at least one elongate blade with a sharpened edge located between guard and cap s~ ces and a frarne supporting the blade(s). However, the invention is also applicable to razors having foils with apertures provided with sharpened edges, rather than elongate blades.
There have been various proposals for mounting a blade assembly on a handle to allow movement of the blade ~semhly with the intention of m~in~ining conrollllity of the skin contacting parts with the skin surface during shaving. For example, many r~ors ~ c~llly marketed have blade ~ssçmhlies which a~e pivotalble about a longihl(1in~1 axes. In our prior patent application No. GB-A-2 1 16470, there is described a razor in which the blade assembly is also pivotable about a transverse axis. With the known constructions, however, the ability of the blade assembly to follow the skin contours is restricted by the limited degrees of freedom of the permitted movement of the blade assembly relative to the handle.
In accordance with t~e present invention there is provided a r~or of the form as initially described above wherein the blade ~cs~mhly is mounted to the handle by an arrangement comprising several spring suspension devices disposed to provide support for the blade assembly at discrete locations so distributed that the blade assembly is moveable relative to the handle with several degrees of freedom including pivotal movement about a lon~ lin~l axis, pivotal movement about a transverse axis, and tr~n~ nal movement in a downward direction substantially perpendicular to the plane defined by said ngitllrlin~1 and transverse axes.
The additional freedom of movement that can be provided by an independent spring suspension system enables the blade assembly to follow more closely the collLuuls of an area of skin being shaved. In particular the longitudinal pivotal axis and transverse pivotal axes are not fixed at predel~....;l.ed positions and they are variably located due to the independent suspension devices. In the case of a blade assembly incorporating one or more çlor~g~te blades, mo ~ c..l~ of the blade assembly in the longihl~1in~1 direction and in the r~alw~d direction are undesirable and the suspension devices can be adapted to hold the blade assembly firmly against translational movements in these directions.
The exact ~ er of spring suspension devices employed is not critical, but three being the ~ lil.. It is preferable for the suspension devices to be so arranged that two of the support locations are spaced lengthwise of the blade assembly and a fur~er support location is spaced transversely from an axis c~nn~c~ing said two support locations. Conveniently four suspension devices are provided and are located in oppositely disposed pairs, e.g. adjacent the respective corners of a frame of the blade ~cs~mbly.
~e devices may consist of sr~ring~ such as integrally moulded plastic Spr~ngs, bow springs or wire torsion springs, or may comprise struts with associated .
coll Co~llplesslon S~ gS.
The invention is applicable to razors having penn~n~ntly mounted blade assemblies, and to ra~ors with blade ~semblies in ~e form of replaceable cartridges. In dle latter case, the suspension devices could be inco.~o~ d with the cartridge and have detachable connections to the handle, or they may be fixed to the handle and either detachably coupled directly to thecartridge or co~ e~ d to a cartridge carrying member with which the cartridge is releasably eng~ge~ble, such as by a sliding connection in a m~nner known per se.
Some particular embo-1imçntc of the invention are described below with reference to the accompanying drawings, in which:-Figure 1 shows in perspective a first embodiment of the invention;
Figure 2 is an underneath perspective view of a shaving cartridge according to a seco~d embodiment of the invention, Figure 3 shows the cartridge of Figure 2 in end view and on an enlarged scale; and Figure 4 is a perspective view of the third embodiment of the mvenhon.
Figure 1 illustrates l~e upper part of a razor equipped with anindependent suspension system in accordance with the invention. Only the upper portion 1 of the razor handle is shown, the lower portion, by means of which the handle is gripped in the hand, having being omitted as * is unimportant to the inventive concept. Mounted to the upper handle portion is a cartridge 2 having a gton~rally rect~ngl-lar frame 6 in which a pair of elongate blades 3 with parallel edges positioned in tandem are mounted between guard and cap surfaces 4 and 5 respectively.
The blades may be fixedly mounted in the cartridge frame, or they may be movable, e.g. downwardly against restoring forces exerted by return spring e1t?m~n~.c as known in the art. The cartridge 2 is connected to the upper handle portion 1 by four independent suspension devices respectively W O 97/26119 rCT/GB97/00121 coupled to the cartridge ~ cPnt the corners of the carhidge frame. Each of the suspension devices consists of a wire torsion spring 8 having a coiled section 9 with two arms 10, 11 e~tentling away from the coil at an acute angle with respect to each other. The free ends of ~e arms 10, 11 are respectively coupled to the handle and the cartridge for pivotal movement about axes directed lt n~ (lin~lly of the cartridge. Conveniently, inwardly bent arm portions are inserted rotatably in holes provided in the ends of the upper handle porhon and the cartridge. The suspension springs 8 bias the cartridge to a rest position inwhich the cartridge is positioned relative to the handle as shown in Figure 1.
By virtue of the cartridge being independently and resiliently supported at fourdiscrete points it has several degrees of freedom for movement relative to the handle. In particular, the car~idge can move from the rest position under forcesexerted on the car~idge during use by:
a~ translational movement in the duwllw~d direction, indicated by arrow 12;
b) a downward displacement of the front part, or the rear part, of the cartridge reslll*ng in an effective pivotal movement about an axis ext~n~1ing longihl-lin~lly of the car~idge; and c) a downward ~licpl~rem~nt of either end of the cartridge reslllting in an ef~ective pivotal movement or tilting about a transverse axis.
Of course these movements are not necess~rily distinct and they can occur in any combinations enabling ~e guard and cap surfaces to follow closely ~e contours of the skin area over which they pass during shaving. The cartridge is not constrained to pivot about prede~ ed longi~l-lin~l and transverse axes fixed relative to the ra~:or handle, but the suspension springs allow the cartridge to float so that ~e effective positions of the pivotal axes are CA 02242529 l998-07-08 W O 97/26119 PCT/GB97tOO121 variable. The extent of permitted movement does not need to be great.
One direction in wlhich the car~idge is held firmly ~in~t movement by the torsion springs 8 is lon~ (lin~lly of the cartridge, i.e. parallel to the blade edges. Also, translational movement in the rearward direction inl1ic~te~ by arrow 13 is also resi~te-l as is rearward displ~c~ment of either end of the cartridge which would result in an effective pivotal or yaw movement about an axis exten~in~ in the dowl~wal(l direction.
In the second embodiment illustrated in Figures 2 and 3, ~e independent suspension devices consist of four bow springs 28 arranged in opposed pairs. The cartridge 22 includes a frame 6, in this case with three blades 3 carried on blade carriers 33 guided ~or movement in slots in the end walls of the frame, and urged upwardly by springs. The upper arm 31 of each bow spring 28 has an L-shaped free end held fa~nly connected to the cartridge frame by a clamp 34. As may be seen clearly in Figure 2, the front and rear frame elements are provided with notches throug~h which the upper arms 31 of the bow springs pass freely. The free ends of the lower arms 30 of the bow springs form ~tt~chment points ~or connection to the razor handle, e.g. by a clamp arrangement which could be releasable to facilitate replacement of the cartridge with attached suspension springs.
It will be understood ~at although the bow springs are located nearer the centre of the cartridge than the ends, they provide for substantiallythe same freedom of movement of the cartridge relative to the handle as described above in relation to the first embo-liment In particular, the ~nclsltional and angular movements (a) to (c) explained above are pennit~e~l In Figure 4 there is shown an embodiment of the invention in which the upper portion 51 of the handle inchl~1es four bearing blocks 64 with longihl-lin~l bores ~n which axle pins 65 are rotatably received. The axle pins have enlarged heads 66 at their outer ends with transverse through bores 67.
Generally upright struts 68 are slidably guided in the bores 67 and are providednear their upper ends with flanges 69 which act as stops for the upper ends of coil springs 70 to act ~in~t, the springs being coaxially mounted on the struts and having their lower ends resting on the axle pins. Thus, the springs 70 urge the struts 68 ul~w~ly to a rest position in which enlargements or stop elements (not shown) provided on ~e lower ends of the struts abut against the enlarged heads 66 of the axle pins. The upper end of each strut is rotatably and pivotally connected to the frame 56 of the blade ~sembly or cartridge 52. (Only the frame of the blade assembly is shown in Figure 1, but it will be understood thatit will include at least one elongate blade as well as guard and cap surfaces asin the previous embo(1im~ntc ) Conveniently each stmt 68 has an element, e.g.
a ball fastened to its upper end and received in a complement~ry slot 72 ~xt~ntling inwardly from the adjacent end of the cartridge frame. At least one pair of longit~ldin~lly aligned axle pins 65, and possibly both pairs, have eye members 75 keyed to their inner ends and relatively strong tension springs 76 are connected between ~ese eye members and spring anchorages 77 fixed on the upper handle porl~on 51 for the tension springs to bias the axle pins 65 to the illustrated rotational positions in which the struts 68 are substantially ~pright The in(1epen-1~nt spring suspension devices of the razor of Figure 4 enable the cartridge 52 to move away from the rest position to which it is biased by virtue of the springs 70, 76, with the same freedom~ of movement (a) to (c) described with reference to Figure 1. Downward displacement at each corner of the cartridge is permitted by the spring 70 and associated slidably guided strut 68 located adjacent ~at corner. A small degree of ~n~ r movement of ~e struts 68 is permitted by rotahon of the axle pins 65 about their axes against the bias of the tension springs 76, such An~l~r movement being necessary to allow the cartridge to pivot about a lon~ f1in~1 axis. The springs 76 are strong enough to resist rearward movement of the cartridge under forces normally encountered during shaving. Lon~ lin~1 movement of ~e cartridge is prevented by abutment between the car~idge frame and the struts.
It will be understood that the illustrated razors are exemplary embodiments of the invention and other independent suspension systems are also possible which can provide the several degrees of freedom of car~idge movement to allow the contours o~ the slcin to be followed closely during shaving. While it is apparent that modifications and changes can be made within the spirit and scope of the present invention, it is our intention, however, only to be limited by the appended clairns.

Claims

1. A safety razor having a handle and a blade assembly mounted to the handle by an arrangement permitting movement of the blade assembly relative to the handle, characterised in that the mounting arrangement comprises several spring suspension devices disposed to provide support for the blade assembly at a plurality of discrete support locations so distributed that the blade assembly is movable relative to the handle with several degrees of freedom including (i) pivotal movement about a longitudinal axis, (ii) pivotal movement about a transverse axis, and (iii) translational movement in a downward direction substantially perpendicular to the plane defined by the longitudinal and transverse axes, and wherein first and second of said discrete support locations are spaced lengthwise of the blade assembly and a third of said discrete support locations is spaced transversely from an axis connecting said first and second discrete support locations.

2. A safety razor according to claim 1, wherein the spring suspension devices urge the blade assembly to a rest position in a predetermined plane from which said blade assembly is movable according to any of the movements (i) to (iii) or any combination of said movements.

3. A safety razor according to claim 1, wherein there are four suspension devices arranged in first and second opposed pairs, said first pair being disposed at first and second of said discrete support locations along a first axis extending lengthwise of the blade assembly, and said second pair being disposed at third and fourth of said discrete support locations along a second axis extending lengthwise of the blade assembly, said second axis being spaced transversely from said first axis.

4. A safety razor according to claim 3, wherein the discrete support locations are adjacent respective corners of a frame of the blade assembly.

5. A safety razor according to claim 1, wherein the suspension devices consist of spring members.

6. A safety razor according to claim 5, wherein the spring members are bow springs.

7. A safety razor according to claim 5, wherein the spring members are torsion springs.

8. A safety razor according to claim 1, wherein the suspension devices are directly connected to a blade assembly frame.

9. A safety razor having a handle and a blade assembly mounted to the handle by an arrangement permitting movement of the blade assembly relative to the handle, characterised in that the mounting arrangement comprises several spring suspension devices disposed to provide support for the blade assembly at a plurality of discrete support locations so distributed that the blade assembly is movable relative to the handle with several degrees of freedom including (i) pivotal movement about a longitudinal axis, (ii) pivotal movement about a transverse axis, and (iii) translational movement in a downward direction substantially perpendicular to the plane defined by the longitudinal and transverse axes, and wherein the suspension devices comprise slidably mounted struts pivotally coupled to the blade assembly and compression springs coaxial with the struts.