Razor blades
United States Patent Griffiths 1 1 Apr. 29, 1975 [5 1 RAZOR BLADES 2239.536 10/1939 Muros 30/346.52  
  I 3&#39; 2,306,782 12/1942 Gingras i 30/402 X [75] invent Rupe&#34; Grlmthsi Maldenhmd- 2.680.290 6/1954 Stcinberg... 30/34652 England 3.388.831 4/1966 Hansom 30/402 [73] Assignee: Wilkinson Sword Limited, High Wycombe, Buckinghamshire. Primary E.\&#39;uminerAl Lawrence Smith England Assistant E.uiniirierMargaret Joyce [22] Filed Au 1 1973 Attorney. Agent, or FirmBrooks Haidt Haffner &amp;  
  Delahunty [21] Appl, No.: 384,750  
  [57] ABSTRACT [30] Foreign Application Priority Data Au H United Kindom Razor blades of the type having a moulded plastics i i i support member with a blade member set therein at a [52] U 5 Cl 30/34 30/47 0/346 predetermined angle and with a cutting edge exposed [5 I] l at a predetermined spacing from the support member u 3 Q 4 .34 52 402 are disclosed such blades having an indicator mark new Search 0/47 3 A 6 thereon which is visibly altered when the blade is [56] References Cited used UNITED STATES PATENTS 15 Claims, 9 Drawing Figures 1,608,274 11/1926 Grayson 30/34 A PATENTEUAPRZSISYS 3,879,844  
 SH&#39;L&#39;EI 1 OF 3 L. J I I PNENTEUAPRZSISYS RAZOR BLADES FIELD OF INVENTION This invention relates to razor blades of the type in which the blade is embedded at a predetermined angle in a support member of moulded plastics material, the blade and the support member forming a shaving unit which can be fitted into the head of a razor and replaced by a fresh unit when the first unit becomes no longer suitable for further use. For convenience herein such a shaving unit will be referred to as a mounted blade.  
 PRIOR ART Razor blades of the foregoing type are disclosed, for example in our U.K. patent specification No. 1,160,543. Such blades are frequently sold packaged in dispenser containing a plurality of blades from which the blades can be dispensed one at a time for fitting to the razor head, see, for example, our U.K. patent specification No. 1,160,542. Frequently such dispensers will also comprise a storage compartment for used blades.  
 OBJECTS OF INVENTION A first object according to the present invention is to provide an improved mounted blade for packaging in a dispenser.  
  A further object according to the invention is to provide an improved form of dispenser for such blades.  
 SUMMARY OF INVENTION The first object of the present invention is achieved by providing on a mounted blade indicator mark, which mark is adapted to be visibly altered, thereby to give a visual indication of blade use, by at least one of the following: immersion of the blade in water, contact with shaving soap or shaving cream or a component thereof, mechanical abrasion by the skin or the mechanical operation of removal of the blade from the dispenser, loading into the razor, unloading from the razor or return to the dispenser. By visible alteration is meant an alteration which is visible to the naked eye, and thus excludes scratches and other marks on the blade which will occur during normal usage but which will only be visible upon microscopic examination.  
  By providing such an indicator mark on a mounted blade an improved form of dispenser can be devised in which all the blades contained therein can be visibly displayed and the purchaser can see at a glance that the dispenser is full and that all the blades are unused, and thereafter can see how many unused blades remain in the dispenser at any time. Also by providing an indicator mark on each blade, used blades can be returned to the dispenser without risk of the user thereafter confusing used blades with unused blades. This enables improved dispenser to be designed to which the blades can be returned after use without the necessity of an extra storage space for the used blades.  
  Also provided in accordance with this invention is a dispenser containing a plurality of mounted blades visibly displayed therein, each such blade displaying an indicator mark as aforesaid. Preferably, the dispenser comprises substantially flat tray in which the blades are retained in juxtaposed position.  
  As already indicated, the present invention is applicable to mounted blades, in which case the indicator mark is preferably provided on the support member rather than on the blade itself, and preferably on the underside thereof, i.e., the undersurface of the support member when the mounted blade is positioned in the razor in a position ready for use. In such a case, the mounted blade will, of course, be positioned in the dispenser with the underside uppermost.  
 DETAILED DESCRIPTION The invention will be further described with reference to the accompanying drawings in which:  
  FIGS. la and 1b are, respectively, a plan and an underside view of a mounted blade of the type described in our U.K. patent specification No. 1,160,543 and modified in accordance with the present invention;  
 FIG. 1c is a section taken on the line [-1 of FIG. 1b;  
  FIG. 2a is a plan view of a dispenser containing a plurality of blades of the type shown in FIGS. la-c,  
  FIG. 2b is a section taken on the line lI-ll of FIG. 2a;  
  FIGS. 3 and 4 are underside views similar to FIG. 1b, of mounted blades according to the invention having alternative forms of indicator mark;  
  FIG. 4a is a view similar to that shown in FIG. 4 but after use of the blade; and  
  FIG. 5 is a side view, partly in section, of the blade shown in FIG. 4 mounted for use in a razor head.  
  Referring first of all to FIGS. la-lc, the mounted blade comprises a support member 1 of plastics material in which is embedded a blade 2, the blade projecting therefrom at a predetermined angle. The mounted blade is adapted to be inserted and held in a razor head (see FIG. 5) in a manner similar to that described in our U.K. patent specification No. 1,160,543, to which reference should be made for further details of the construction of the mounted blade and the razor head.  
  In accordance with the present invention the underside of the plastics support member, see FIG. lb, is provided with an indicator mark 3, in this embodiment, in the form of an elongated strip of porous material adhered to the surface of the plastics support member. Further details of the indicator mark, and various alternative forms of mark will be discussed hereinafter.  
  Referring now to FIGS. 2a and 2b, the dispenser comprises a walled tray 4, e.g., of moulded plastics material, into which are slotted six mounted blades of the type illustrated in FIGS. la-c. The opposite longitudinal walls of the tray are formed internally with inclined ribs 5, arranged in pairs on opposite sides of the tray, and forming six compartments into which the mounted blades are slotted one behind the other with their respective undersurfaces uppermost. The arrangement is such that a razor head can be inserted into the dispenser tray and engaged over any one of the six blades which can then be lifted out of the dispenser ready for use. After use, the used blade can be returned to the dispenser by the reverse procedure. If desired resilient retaining lugs can be moulded into the tray in order to hold the blades firmly in position. Further details of the loading and unloading operation can be obtained from our U.K. patent specification No. l,160,542, in which a similar dispenser is described. At the right-hand end of the tray as shown there is one empty compartment ready to permit a used blade to be inserted before the first of the new blades is removed.  
  As will readily be apparent from FIGS. 20 and 2b, every blade in the dispenser is visible, the tray conveniently being provided, for example, with a transparent removable cover (not shown), and the indicator mark 3 on each blade is also clearly visible. Since, in accordance with this invention the indicator mark is visibly altered by one or more actions, such as loading or unloading the blade into or from the razor, movement of the blade over the skin or by one or more of the materials normally used in shaving, e.g., hot water or shaving soap or cream, the user is immediately aware which blades have been used and returned to the dispenser and which are unused. Thus the user is able to select an unused blade whenever he wishes to do so and is aware of how many unused blades he has left. It will also be apparent from FIG. 2a and 2b, that the dispenser is extremely compact, the overall height, even allowing for a cover, being not much greater than, or even less than, the width of the mounted blades.  
  The indicator mark shown in FIGS, 1a, 1b and comprises a strip adhering to the surface of the blade support member. In a possible preferred arrangement, the mark may be inset into the support during mould- Turning now to the indicator mark, this may take many different forms depending upon its mode of activation. Broadly speaking this can be chemical or physico-chemical, by which is meant operation by, for example, dissolution, etc., or it can be mechanical, for example, the obliteration or making of a mark by a mechanical operation.  
  Considering first of all chemically or physicochemically activated marks, these will be activated by, for example, repeated immersion of the blade in water, which will usually be hot water, or by contact of the blade with the soap or shaving cream used in the shaving process.  
  A particularly simple form of indicator mark consists of a strip 3 of porous material impregnated with a water-soluble dye or pigment which is leached out of the strip upon immersion in water, thereby causing the strip to change colour. For example, the mark may take form of a strip of paper adhered to the blade and impregnated with the red dye known as Dragoco S/072694-E Rose Red. During use, the red dye leaches out of the paper strip which reverts to its original colour, usually, of course, white.  
  A variation of the above consists in an indicator mark comprising a pigment, for example, titanium dioxide, bound in a water soluble binder, for example, poly(vinyl alcohol) or poly(vinyl pyrrolidone). A dispersion of the pigment in a solution of the binder is applied as a thin strip 3 to the underside of the mounted blade and allowed to dry. A white indicator strip will then be apparent on all unused blades, but upon immersion in water the binder will dissolve thereby causing the pigment to disperse and the indicator mark to disappear.  
  Another possibility consists in a strip or patch 3 of porous material secured to the blade and containing a water-soluble dye dispersed therein in finely divided solid form. In this form the dye will impart negligible colour to the indicator strip or patch, but as soon as the blade is moistened the particles of dye will dissolve and disperse thereby causing the strip or patch to change colour.  
  In an alternative arrangement a pigmented or otherwise opaque water-soluble film can be used to cover up a permanent mark of a different colour, which latter mark will be exposed after the blade has been immersed in water. In another modification, the mark may take the form of a patch or strip of insoluble material adhered to the blade by a water-soluble adhesive. Again use of the blade will be indicated by disappearance of the patch, possibly with the consequent exposure of an underlying permanent mark.  
  One such embodiment is shown in FIG. 3. In this embodiment the indicator mark consists of a circular opaque paper patch 5 secured to the support member 1 by a water-soluble adhesive and obscuring a permanent circular mark 6, e.g., a red spot of water-insoluble paint applied to the support member under the patch 5. In the embodiment illustrated the patch is shown half broken away to expose the underlying permanent mark. Normally, of course, the whole of the permanent mark will be obscured by the patch until such time as the blade is immersed in water thereby to dissolve the adhesive and effect the removal of the patch. Instead of a water-insoluble patch secured by a water-soluble adhesive, the patch 5 can be of an opaque watersoluble plastics material, for example poly(vinyl alcohol) or poly(vinyl pyrrolidone) containing a material, e.g., titanium dioxide, to make the polymer opaque.  
  Another possibility consists in a film of water-soluble material, possibly coloured, deposited over the cutting edge of the blade; however, such an arrangement is somewhat less preferred.  
  As this detailed description proceeds, it will be apparent that the term blade is being used herein in a generic sense as covering the mounted blade as a whole. Only when the context requires, as in the immediately preceding paragraph, will the term blade be used specifically as meaning the member which is embedded into the support and which provides the cutting edge.  
  The indicator systems so far discussed depend upon the solvating powers of water on various materials. Alternative systems are possible utilising, for example the difference in environmental pI-I between an unused blade in a dispenser and a blade in a use environment, e.g., in contact with or immersed in water used during shaving and/or in contact with shaving soap or cream, particularly those of an alkaline character. For example, a porous indicator strip 3 or patch may be affixed to the blade, which strip or patch is impregnated with an acid base indicator composition containing an acidbase indicator in its acid indicating form, the composition being adapted to change colour when in an aqueous environment having a pH in the range 7.0 to 8.5 so that when the blade is immersed in water of approximately neutral pH, or more especially, a shaving soap solution of alkaline pH, the indicator composition changes colour, thereby giving an indication that the blade has been used. As with the type of marks previously discussed, which depend on the solvating power of water, many variations will be possible using acidbase indicators. In order to control the colour change suitable buffering agents may be incorporated into the mark along with the indicator. A typical indicator composition might be, for example, a mixture of Congo Red and an excess of a water-soluble acid, e.g., citric acid, incorporated into a porous matrix and applied to the support member in a prominent position. The excess acid will maintain the indicator in its blue colour form until the acid is leached out or neutralised by the soapy water, whereupon the indicator mark will change to red. Alternatively or additionally dyes or pigments can be added to modify the colour change. Instead of an acid-base indicator, the indicator mark of the blade may contain, for example, a spot test reagent sensitive to metal ions in the water used for shaving or in the shaving soap or cream. Desirably such indicator marks will be arranged to change colour only after repeated immersion in water thereby to avoid accidental triggering of the colour change by condensation or accidental immersion in water.  
  Rather than rely on any one effect to bring about the visual alteration of the marker, a combination of effects can be utilised, for example, both dissolution of a marker component and colour change of an acid-based indicator.  
  Instead of relying on an acid-base indicator to provide a colour change in the indicator mark, use may be made of an anhydrous salt which changes colour upon hydration. Other hydration effects may also be utilised, such as the release by hydration of a coloured compound contained in a molecular sieve. Hydration effects which, for example cause polymeric marker to swell and change shape may also be used as may be the rupture of a membrane by hydration to cause two previously separated compounds to intermingle and react to produce a coloured or otherwise visually distinct product.  
  Although less preferred by reason of the variation in composition of shaving soaps and creams and also by the fact that shaving soap or cream may not be used at all in shaving, indicator systems depending on the surface active properties and/or chemical constituents, of the soap or cream can be used. For example, a grease or wax-based marker can be used which will be removed by the action of the soap or shaving cream, thereby to indicate by its disappearance, and possibly the exposure of an underlying permanent mark, the use of the blade. Metal ions in the marker can be caused to react with a component in the soap or vice versa to provide a visible effect, for example, precipitation or a colour change in a spot test reagent.  
  Since shaving is usually done with hot water, indicator marks sensitive to heat can be used, but again less preferably, especially marks sensitive to heat alone. Heat effects in combination with another effect may, however, be suitable. For example, the indicator mark may comprise a mixture of relatively low melting point material, e.g., wax, in combination with a surfactant. Heating melts the wax thereby releasing the surfactant which then assists in the removal and dispersion of the wax marker. This type of mark may be improved by incorporating an inert filler into the wax-surfactant mixture. The filler and surfactant, which do not melt, help to retain the molten material in place when heated in the absence of water, for example, when on display in a shop window, but when exposed to a combination of heat and water, the mark is removed, possibly to reveal an underlying permanent mark. Alternatively a marker may be removed by a combination of heat and movement of the blade against the skin while shaving.  
  Indicator marks which are affected by a mechanical operation associated with the action of loading a blade into the razor and shaving include, for example, a mark which is rubbed off by mechanical abrasion against the skin, the mark being either of a powdery material or other mechanically weak material, or a label or patch loosely adhered to the blade. Alternatively, such marks can be affected by the physical operation of loading the blade into the razor and/or removal of the blade from the dispenser.  
  A blade having a mechanically actuated indicator mark according to the invention is illustrated in FIGS. 4, 4a and 5. The blade illustrated in FIG. 4 is similar in all aspects to the blade illustrated in the previous embodiments except that in this case the indicator mark comprises a patch of rupturable or tearable material, e.g., paper, permanently secured on the underside of the support member 1 and stretched over the groove 8 in the underside of the support member. This groove 8 provides a seating into which seats, when the blade is loaded into a razor head 9 ready for shaving (see FIG. 5), a spring-loaded ball detent 10 thereby to retain the blade in position in the razor head. The patch 7 is so positioned on the support member that the ball detent 10, when it engages the groove 8 permanently deforms or ruptures the patch 7, to form for example, a circular tear or depression 7a, as shown in FIG. 4a. The blade is thus permanently marked as a used blade. At the end of the shaving operation or when the blade is no longer usable, it can be returned to the dispenser which may be for example, of the type shown in FIGS. 2a and 2b and an unused blade selected for further use. The user will then be able to see which blades in the dispenser have been used and those which have not by simple inspection of the patch 7 on each blade.  
  In other arrangements, loading of the blade and/or removal of the blade from the dispenser can be used to mark the blade in some way or other, for example, by scratching or fracturing a part of the support member, or physically removing a film or barrier over the cutting edge of the blade. Alternatively, the loading or dispensing operation can cause the rupture of a microencapsulated dye or pigment to stain or colour an area of the blade, or the rupture of a film or patch on the blade to expose a permanent mark therebelow. In yet another possibility, the dispensing, loading or the action of returning the blade to the dispenser may be arranged to cause a physical alteration in the blade to prevent loading of the blade into the razor a second time.  
  Many variations in the marking systems discussed above will be possible and other types of indicator mark will be possible without departing from the scope of this invention. Also it will be apparent that by providing an indicator mark which is visibly affected over a period of time, for example, a gradual colour change, an indication may be obtained of the period of time in which any one blade has been in use.  
 I claim:  
  1. A mounted razor blade of the type comprising a moulded plastics support member in which is mounted, at a predetermined angle, a blade member having an exposed cutting edge located at a predetermined spacing from the support member, wherein there is provided on said support member an indicator mark visibly alterable in appearance by use of the blade.  
  2. A blade according to claim 1, wherein said mark is visibly alterable in appearance by immersion of the blade in water.  
  3. A blade according to claim 2, wherein the mark comprises a water-soluble material which dissolves upon immersion of the blade in water thereby to effect a visible alteration in the mark.  
  4. A mounted razor blade of the type comprising a moulded plastics support member in which is mounted, at a predetermined angle, a blade member having an exposed cutting edge located at a predetermined spacing from said support member, wherein there is provided on said support member an indicator mark comprising a water-soluble colourant absorbed in a watersoluble porous carrier material bonded to the support member, said colourant being leachable from said porous carrier material thereby to cause said mark to change colour upon immersion of the blade in water.  
  5. A mounted razor blade of the type comprising a moulded plastics support member in which is mounted, at a predetermined angle, a blade member having an exposed cutting edge located at a predetermined spacing from said support member, wherein there is provided on said support member an indicator mark comprising a water-insoluble material bonded to the support member by a layer of adhesive, said adhesive being water-soluble and thereby being effective to cause separation of said water-insoluble material from the support member and hence the disappearance of said mark upon immersion of the blade in water.  
  6. A blade according to claim 5, wherein the mark comprises a water-soluble pigment incorporated in a water-soluble binder adhering to the support member.  
  7. A blade according to claim 6, wherein the mark comprises titanium dioxide incorporated into a film of water-soluble polymer deposited on the support member.  
  8. A blade according to claim 5, wherein the mark comprises a patch of opaque water-insoluble material affixed to the support member by a water-soluble adhesive, and wherein the support member is provided with permanent mark underlying said patch, said permanent mark being exposed to view upon immersion of the blade in water and dissolution of said adhesive.  
  9. A mounted razor blade of the type comprising a moulded plastics support member in which is mounted, at a predetermined angle, a blade member having an exposed cutting edge located at a predetermined spacing from said support member, wherein there is provided on said support member an indicator mark comprising a film of water-soluble material deposited on the support member, immersion of the blade in water thereby being effective to dissolve said film and to effect the disappearance of said mark.  
  10. A blade according to claim 9, wherein said film is opaque and wherein said support member is provided with a permanent mark underlying said film, the said permanent mark being exposed to view upon immersion of the blade in water and consequent dissolution of said film.  
  11. A mounted razor blade of the type comprising a moulded plastics support member in which is mounted, at a predetermined angle, a blade member having an exposed cutting edge located at a predetermined spacing from said support member, wherein there is provided on said support member an indicator mark comprising an acid-base indicator changeable in colour upon immersion of the blade in water of neutral or alkaline pH.  
  12 A blade according to claim 11, wherein the mark comprises a porous water-insoluble carrier material bonded to the support member and impregnated with the acid-base indicator.  
  13. A razor dispenser comprising a receptacle, a plurality of blades removably received in said receptacle, each of said blades being of the type comprising a moulded plastics support member in which is mounted, at a predetermined angle, a blade member having an exposed cutting edge located at a predetermined spacing from the support member, each of said blades being positioned in said receptacle so the plastics support member of each blade is visible therein and so that each of said blades is separately removable therefrom, wherein the plastics support member of each of said blades is provided with an indicator mark in a position to be visible while the blade is in the receptacle, said mark being visibly alterable by removal and use of the blade.  
  14. A razor blade dispenser according to claim 13, wherein said receptacle comprises a tray in which the plurality of blades are disposed in a parallel array.  
  15. A razor blade dispenser according to claim 14, wherein said receptacle comprises a transparent lid fitting over said tray.  
  UNITED STATES PATENT OFFICE QERTIFICATE 0F CORRECTION PATENT NO. 3, 79, DATED April 29, 1975 |NVENTOR(5) Rupert Griffiths It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:  
 Column 7, line 3 (Claim 4) &#34;soluble&#34; should read -insoluble-- Signed and Scaled-this twenty-second Day Of July 1975 [SEAL] RUTH c. MASON c. MARSHALL DANN Arresting Officer Commissioner of Parents and Trademarks