RAZOR CARTRIDGE WITH SHAVING AID AND METHOD OF MANUFACTURE

Abstract: A method of attaching a shaving aid unit (1) to a razor head (11) comprises the steps of: producing an elongate length (26) of shaving aid; separating the length of shaving aid into a plurality of individual shaving aid units (27, 28, 29); providing a razor head (11) having a shaving aid unit- receiving formation (16); and feeding at least one of said units (27, 28, 29) into said formation (16) for retention therein.

Description: The present invention relates to a razor head for receiving a shaving aid and to a method of attaching a shaving aid to a razor head. It is known to provide a shaving aid on the head of a razor for use in wet shaving. Usually the shaving aid is incorporated in one of the face-engaging surfaces of the head of the razor, e.g., the cap or the guard bar. Typical prior art razor heads incorporating shaving aids in the cap or in the guard bar are disclosed and described in US-A- 4,170,821, GB-A- 1,157,640 and IT-A- 991,064 in the name Raffaele Tipaldi. Also GB-A-2,024,082 discloses a razor with a recess for receiving a moulded insert of a polymer mixture. US-A- 4,170,821 discloses a shaving aid in the form of polyethylene oxide as well as other preparations incorporated into a razor cartridge in a number of ways. GB-A- 1,157,640 discloses a sponge-like strip impregnated with a hair softener mounted on the top of the razor head, whilst IT-A- 991,064 discloses a soap dispenser mounted in front of the blade edge. In EP-A-184,440 there is disclosed a method of forming a shaving unit and a shaving unit which have the features of the precharacterised clauses of claims 1 and 3 respectively. One object of the present invention is the provision of a wet shaving safety razor head incorporating a shaving aid in a face-engaging surface of the head whose structure and method of manufacture lends itself to modern high-speed mass production methods. A special feature of the invention is the provision of a shaving aid unit receiving formation and method of inserting the aid into the formation with high manufacturing speed and economy whereby incorporation of the aid into low cost disposable razors can be achieved competitively. According to one aspect of the invention, there is provided a method of attaching an elongated shaving aid unit to a razor head, comprising the steps of: producing an elongate length of shaving aid; separating the length of shaving aid into a plurality of individual shaving aid units; providing a razor head having a track which forms a shaving aid unit-receiving formation in a face-engaging surface of the razor head; characterised by the steps of: providing said track with at least one open end thereof; and sliding said shaving aid unit through at least one said open end into said track along the lengthwise direction thereof such that said shaving aid unit is frictionally engaged and retained in said track by retaining means of said razor head. Preferably the step of sliding includes the step of frictionally sliding said shaving aid unit into said track along the lengthwise direction thereof such that said shaving aid unit is frictionally engaged and retained in said track by said retaining means. The method can include the step of flaring the inlet side of the restrictions to facilitate feeding the unit into the track. Overfeeding the unit is desirably prevented by providing a stop at the end of the track opposite to the inlet. The spaced restrictions may be created by bulging spaced portions of the track. Alternatively, or in addition, the spaced restrictions may be created by providing shaving aid unit-retaining formations on the face-engaging surface adjacent the track. The shaving aid unit-retaining formations may comprise spaced clips provided on the face-engaging surface adjacent the track; preferably the spaced clips are arranged in pairs so that the clips project toward one another from opposite sides of the track. Conveniently, the spaced clips are located in the region of the bulging portions of the track. This can be achieved by disposing the spaced clips in alignment with the bulging portions. According to another aspect of the invention, there is provided a razor head for receiving an elongated shaving aid unit, comprising: a shaving aid unit-receiving formation in a face-engaging surface of the razor head, said shaving aid unit-receiving formation including a track in the face-engaging surface of the razor head; retaining means for retaining at least one shaving aid unit in said track, said retaining means including spaced restrictions which engage and retain at least one said shaving aid unit in the track; and characterised in that said track is open at least one end thereof to permit sliding of said shaving aid unit through at least one said open end into said track along the lengthwise direction thereof. Preferably said spaced restrictions include a plurality of bulging spaced portions on a bottom surface of said track. Desirably each said bulging spaced portion has an entry portion which is flared upwardly and extends in the lengthwise direction of said track. The bulging spaced portions may each have a convex configuration. The spaced restrictions preferably include spaced shaving aid unit-retaining formations on the face-engaging surface adjacent the track and extending at least partially over and in frictional engagement with said shaving aid unit. Desirably stop means is provided at at least one end of said track for restraining movement of said shaving aid insert in the lengthwise direction of said track once said shaving aid unit is retained in said track. An inlet side of the spaced restrictions can be flared in order to facilitate feeding the or each unit into the track. Shaving aid unit-retaining formations in the form of clips can be provided instead of, or in addition to, the bulged portions. the clips can be arranged in pairs so that they project towards one another from opposite sides of the track. The clips can be arranged in the region of the bulged portions. The head may be formed integrally with a handle as a disposable razor or may be formed as a cartridge having means to attach it to a re-usable handle. Reference is now made to the accompanying drawings, in which: Figure 1 is a perspective view of a razor with a shaving aid unit in place; Figure 2 is an enlarged perspective view of a shaving aid of indeterminate length; Figure 3 is a view similar to Figure 2 showing the shaving aid of Figure 2 separated into individual shaving aid units; Figure 4 is a top view on an enlarged scale, showing a shaving aid unit partially received in a shaving aid recess; Figure 5 is a vertical section of Figure 4 as viewed in the staggered line 5-5; Figure 6 is an enlarged view of a portion of Figure 5 showing a bulge in the bottom wall of the shaving aid recess; and Figure 7 is a sectional view on an enlarged scale in the plane of the line 7-7 of Figure 4. Referring now in detail to the drawings, the reference numeral 11 designates a low cost disposable razor having a handle 12 and a head 13. The head includes a face-engaging surface 14 formed with a shaving aid unit-receiving formation in the form of a recess 16 for receiving a shaving aid unit in the form of an insert 17. The recess 16 is open-ended and defines a track for receiving the shaving aid insert 17 fed into the track from the left end of the track as is apparent in Figures 4 and 5. To facilitate retention of the insert 17 within the track, the face-engaging surface 14 is formed with shaving aid unit-retaining formations in the form of spaced clips 18 and 19 (in this case moulded integrally with the head) which overlay the track and which project toward one another from opposite sides of the track. While the embodiment of the invention described has the clips opposite one another, it is not necessary that they be so arranged. The clips may be staggered or project alternately from side to side. In the region of the clips 18 and 19, the bottom wall 21 of the recess 16 is formed with bulges 22 (see Figure 6) which cooperate with the clips 18 and 19 to accomplish two important effects. The bulges 21 together with the clips 18 and 19 form spaced restrictions along the length of the track. First, the inlet side of the bulge, as indicated at 23 in Figure 5 and 6, provides a flared opening creating a "lead in" for the insert 17 as it is being inserted. Secondly, the clips 18 and 19, singly or in pairs, cooperate with mating bulges 22 to create a restriction to facilitate the creation of friction to retain the shaving air insert in place. As stated above, it is not necessary that the clips 18 and 19 be arranged in opposed pairs as shown in Figure 7 but can be staggered in alternating fashion as they project from opposite sides of the track. Furthermore, the number of clips and the number of bulges is a matter of choice so long as there are sufficient restrictions between cooperating clips and mating bulges to create adequate friction for insert retention. In the embodiment shown a stop 24 is provided in the track opposite the inlet end (see Figure 4) to prevent over-feeding of the shaving aid insert 17. Figure 2 shows an elongate shaving aid 26 of indeterminate length created by extrusion. figure 3 shows the step of separating the elongate shaving aid 26 into individual inserts 27, 28 and 29. These inserts are schematic representations of the insert 17 shown being fed into the track shown in Figures 4 and 5 and illustrated in cross-section in Figure 7. If desired it is envisaged that stops may be provided at both ends of the recess 16 to keep the insert from "walking out" of the recess due, for example, to vibrations encountered during transport of the razor. The shaving aid comprises a structure which has at least one material which aids the process of shaving. The shaving aid may be selected from one or any combination of the following materials. A) A material for reducing the frictional forces between the razor and the skin, e.g. a lubricant. Examples of lubricants include: micro-encapsulated silicone oil; a poly- ethylene oxide in the range of molecular weights between 100,000 and 6,000,000; a non-ionic poly-acrylamide; and/or a natural polysaccharide derived from plant materials such as "guar gum". B) A material which modifies the chemical structure of the hair so that the razor blade can pass through the whiskers easily, e.g. a depilatory agent. C) A cleaning material which allows the whisker and skin debris to be washed more easily from the razor parts during shaving, e.g. a silicone polyethylene oxide block copolymer and detergent such as sodium larnyl sulphate. D) A medicinal agent for killing bacteria or repairing skin damage and abrasion. E) A cosmetic material for softening, smoothing, conditioning or improving the skin. F) A blood coagulant for the suppression of bleeding that occurs from nicks and cuts. The shaving aid may include materials such as polystyrene, polyethylene, polypropylene or polyacetal. As used herein the expression shaving aid may refer to a solid which is either partially water soluble or substantially entirely water soluble. The shaving aid may comprise a solid microporous structure having a water soluble material incorporated therein, or a solid microencapsulating, water soluble, structure having a water soluble material incorporated therein. The foregoing description relates to a disposable razor having a head moulded integrally with a handle but it will be appreciated that the head could be moulded as a separate cartridge for attachment to a handle.

Claims: A method of attaching an elongated shaving aid unit (17) to a razor head (11), comprising the steps of: producing an elongate length of shaving aid; separating the length of shaving aid into a plurality of individual shaving aid units; providing a razor head (11) having a track (16) which forms a shaving aid unit-receiving formation in a face-engaging surface of the razor head (11); characterized by the steps of: providing said track (16) with at at least one open end thereof; and sliding said shaving aid unit (17) through at least one said open end into said track (16) along the lengthwise direction thereof such that said shaving aid unit (17) is frictionally engaged and retained in said track (16) by retaining means (18, 19, 22) of said razor head. A razor head (11) for receiving an elongated shaving aid unit (17), comprising: a shaving aid unit-receiving formation in a face-engaging surface of the razor head (11) said shaving aid unit-receiving formation including a track (16) in the face-engaging surface of the razor head (11); retaining means for retaining at least one shaving aid unit (17) in said track (16); characterized in that said retaining means include spaced restrictions which frictionally engage and retain at least one said shaving aid (17) unit in the track (16); and that said track (16) is open at at least one end thereof to permit sliding of said shaving aid unit (17) through at least one said open end into said track (16) along the lengthwise direction thereof. A razor head according to Claim 2, characterized in that said spaced restrictions (18, 19, 22) include a plurality of bulging spaced portions (22) on a bottom surface (21) of said track (16). A razor head according to Claim 3, characterized in that each said bulging spaced portion (22) has an entry portion (23) which is flared upwardly and extends in the lengthwise direction of said track (16). A razor head according to Claim 4, characterized in that said bulging spaced portions (22) each have a convex configuration. A razor head according to Claim 2 or 3, characterized in that said spaced restrictions (18, 19, 22) include spaced shaving aid unit-retaining formations (18, 19) on the face-engaging surface adjacent the track (16) and extending at least partially over and in frictional engagement with said shaving aid unit (17). A razor head according to Claim 2, further characterized by stop means (24) at at least one end of said track (16) for restraining movement of said shaving aid insert (17) in the lengthwise direction of said track (16) once said shaving aid unit (17) is retained in said track (16).

Inventors: FERRARO, FRANK A., MOTTA, VINCENT C.
Applicants: WARNER-LAMBERT COMPANY
Application year: 1987
Main classification: B26B21
IPC codes: B26B21