JP3117711B2 - Safety razor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a safety razor having a flexible razor blade unit secured to a handle by coupling means configured to allow the flexible razor blade unit to flex during use.

The blade unit is flexible in the sense that it can easily flex about an axis extending parallel to the plane of the blade and substantially perpendicular to the cutting edge of the blade, depending on the forces encountered during normal use. Sex. This kind of safety razor,
For example, it is described in British Patent Specification Nos. 1589591 and 2119690.

One configuration of such a safety razor blade unit comprises a single flexible blade or two flexible blades with a flexible spacer interposed therebetween, such a blade or blade and The spacer is attached to a molded plastic housing that forms a comb guard portion and a comb cap portion, and the teeth of the two comb portions are interconnected by a web that is thin enough to be flexible. The blade unit is connected to the razor handle by connection means that allow the blade unit to flex during use.

The inventor has developed such a safety razor improvement.
In an improved safety razor, a comb made of a mixture of structural polymers such as polyethylene oxide and polystyrene is positioned between the teeth of the comb cap portion so that the blade unit can flex concavely. In addition, the teeth of the molded article containing polyethylene oxide are narrower than the gap between the teeth of the cap portion.

According to the present invention, there is provided a razor blade unit that can be easily deflected about an axis that extends parallel to the plane of the blade and substantially perpendicular to the cutting edge of the blade in response to forces encountered during normal use. A handle, connecting the blade unit to the handle, having connection means for allowing the blade unit to flex, the blade unit having a molded plastic housing forming a comb guard portion and a comb cap portion, A two-blade blade with a blade or spacer in between is clamped between the combs, and the teeth of the two combs are interconnected by a web that is thin enough to be flexible, The unit is
Further comprising a comb-shaped article made of a mixture of polyethylene oxide and a structural polymer, the article being positioned between the teeth of the comb cap portion, the polyethylene oxide-containing article comprising:
A safety razor is provided that is narrower than the spacing between the teeth of the cap portion so that the blade unit can flex concavely.

The teeth of the molded article containing poly (ethylene oxide) are flush with the teeth of the cap part or protrude above the teeth of the cap part.

It is well known to use inserts formed of structural polymers such as polyethylene oxide and polystyrene in the cap and / or guard portions of razors and blade units to improve shaving performance, for example, see British Patent Statement
No. 2024082. Such inserts typically contain 80% by weight of polyethylene oxide and 20% by weight of the structural polymer. The present invention provides a particularly convenient way of incorporating a polyethylene oxide-containing insert into a flexible blade unit of the type described above.

Preferred embodiments of the present invention will now be described by way of example with reference to the accompanying drawings.

 FIG. 1 is an exploded perspective view of a razor, and FIG. 2 is a perspective view of an assembled razor.

The illustrated razor includes a comb guard portion 12 and a comb cap portion 13 with a combination of two single-edged razor blades 14 sandwiching a spacer 15 clamped between these portions (e.g., polystyrene). A) Flexible blade unit 10 with molded plastic housing 11). Blade 14 and spacer 15 are held in place by protrusions on the housing (not shown) and protrusions on spacer 15 (not shown) that engage slots 16 in the blade. Slot 16 is used to allow relative movement of the blade and slot during flexing. Comb-shaped part
12 and 13 are interconnected by a web 17 that is thin enough to make the blade unit 10 flexible.

The blade unit further has a polyethylene oxide-containing comb-shaped molded product 18, the teeth 19 of which are formed in a cap portion.
Positioned between the thirteen teeth, the width of the teeth 19 is less than the gap between the teeth of the cap portion (when the blade unit is not flexed) so that the blade unit can flex concavely.

The teeth 19 of the molded article 18 containing polyethylene oxide are interconnected by a web 20 fixed with an adhesive behind the web 17. As can be seen from FIG. 2, in the assembled state, the teeth 19 of the molded article 18 containing polyethylene oxide are at the same height as the teeth 13 of the cap portion.

1 and 2 further illustrate a preferred method of assembling the blade unit. That is, the polyethylene oxide-containing molded product 18 is a sprue 21 molded together with the molded product until the molded product is joined to the housing 11.
The sprue 21 is not separated from the sprue 21 and is cut off following its connection to the housing 11 (see FIG. 2).

The blade unit 10 is connected to the handle 22 by three columnar members 23 and 24 which are integrally hung from the lower side of the housing 11. The post slidably engages a corresponding slot 25, 26 in the handle head. Column members 23, 24
Extends perpendicular to the parallel plane of the blade and is positioned just below the blade edge, ie, passes through an area bounded by the blade edge. The central columnar member 24 is guided in a straight sliding motion within the slot 26,
Thus, the columnar member centers the unit in the longitudinal direction without interfering with the deflection of the unit. The outer columnar members 23 each have pivot pins 27 projecting through these members parallel to the deflection axis of the blade unit, and these pins 27 allow for movement of the ends of the unit toward or away from each other. An elongated slot 28 formed in the wall of the slot 25 to accommodate the associated deflection of the blade unit.
Has been accepted and guided. Further, the pins 27 prevent the blade unit from being pulled out of the handle.

The columnar member 23 is set at a predetermined position from the end of the unit so that the blade unit can bend in a convex shape when one or both ends of the unit encounters a greater force than the intermediate portion during shaving. Have been.

It has been found that it is necessary to limit the deflection both at the center and at the end of the cartridge to protect the blade unit from damage due to excessive deflection in both the concave and convex states. .

In the concave state, deflection from the undeflected plane is limited by the underside of the platform abutting the center of the handle head. In the raised configuration, deflection of the outer portion of the blade unit is limited by the underside of the outer portion of the platform abutting the outer portion of the handle head.

In certain embodiments, concave deflection is limited to 2.5 mm at the center of the blade unit and convex deflection is limited to 3 mm at the end of the blade unit. The interval between the outer columnar members 23 is
Preferably, it is 2/3 of the total length of the blade unit.

The main forces encountered during shaving are directed perpendicular to the plane of the blade and pass through the area bounded by the cutting edge of the two-blade blade unit. Since the columnar members 23 and 24 match these forces, no large bending moment is applied to these columnar members. If the columns 23, 24 are not aligned with these forces, the bending moment will tilt the columns and push the pins 27 into the guide slots 28.

Although the embodiment in which the polyethylene oxide-containing molded article is formed separately from the housing 11 and bonded to the housing 11 with an adhesive has been described, the polyethylene oxide-containing molded article is formed by a two-stage molding method, and in particular, one of the materials is used. It may be performed in situ, by molding first, then molding the second material in situ, thereby molding the different materials into a single component. The method can be used to form the housing and the molded article containing polyethylene oxide as a single component. (To form the desired gap between the teeth of the cap and the teeth of the molded article containing poly (ethylene oxide), the separated parts are inserted into the mold before injection of the mixture containing poly (ethylene oxide).) There is no need for adhesive bonding, and the use of adhesive reduces the flexibility of the unit, which is enhanced.

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Claims (2)

(57) [Claims] 1. A razor blade unit that is capable of easily flexing about an axis extending in parallel with the plane of the blade and substantially perpendicular to the cutting edge of the blade, in response to forces encountered during normal use. A handle and a connecting means for connecting the blade unit to the handle, which allows the blade unit to bend; the blade unit has a molded plastic housing forming a comb guard portion and a comb cap portion; A two-blade blade with a blade or spacer in between is clamped between the combs, the teeth of the two combs are interconnected by a web that is thin enough to be flexible, and the blade unit Further comprises a comb-shaped article made of a mixture of polyethylene oxide and a structural polymer, the article positioned between the teeth of the comb cap portion, Ethylene-containing molded article is narrower than the spacing between the teeth of the cap portion to allow the blade unit is flexed concavely safety razor. 2. The safety razor according to claim 1, wherein the teeth of the molded article containing polyethylene oxide are at the same height as the teeth of the cap portion or project above the teeth of the cap portion.