The invention relates to shaving razors, and blade subassemblies therefor and methods of manufacture.
Shaving razors often include a plurality of blades that are secured in a desired position in a plastic housing. The housing is often provided with a guard with fins or other skin engaging structures made of elastomeric material in front of the blades, and a cap on which the skin can slide behind the blades. A shaving aid (e.g., a lubricant agent dispensing mechanism) can be incorporated into the cap and, in some cases, the guard. The blades can be stationary or movable, and the housing can be fixed to a handle or movably mounted on the handle, to, e.g., assist in following the contours of the skin during shaving.
Examples of some different types of shaving razors are described in U.S. Pat. Nos. 5,313,706; 5,369,885; 5,416,974; 5,546,660; 6,032,372; 6,145,201; 6,161,288; 6,216,345; 6,216,561; and 6,397,473.
In one aspect, the invention features, in general, a subassembly for a shaving razor including a plurality of elongated metal blades. The blades having cutting edges defining a shaving surface longitudinal ends and are secured at their longitudinal ends to first and second plastic blocks to provide an integral unit.
Particular embodiments of the invention may include one or more of the following features. In particular embodiments the longitudinal ends of the blades are received in slots in the first and second plastic blocks. The longitudinal ends of the blades and the slots have mating locking structure to secure the longitudinal ends to the first and second plastic blocks. The locking structure includes projections projecting into the slots that engage holes through the longitudinal ends. The longitudinal ends have a thickness that is greater than the width of the slot minus the height of the projection.
In some embodiments each blade includes an elongated cutting member having a cutting edge and an elongated support to which the elongated cutting member is attached, with the longitudinal ends of the elongated support being welded to each other at the two sides. In some other embodiments, each blade includes an elongated cutting member portion having a cutting edge and an integral elongated support portion bent downward from the cutting member portion, with the longitudinal ends of the elongated support portion being welded to each other at the two sides. In still other embodiments, each blade includes an elongated cutting member having a cutting edge, and the longitudinal ends extend from the elongated cutting member. The subassembly can have two blades, three blades, four blades or five blades or more. The cutting edges can be located in a common plane. The subassembly can have a snap-fitting structure for connection to a housing of a shaving razor.
In another aspect the invention features, in general, a shaving razor including a subassembly as already described, and a housing having a recess in which the subassembly is secured. The razor can have a stop member secured to the housing with the cutting edges resting against the stop member. The razor can have a biasing member secured to the housing and biasing the blades so that the cutting edges are biased against the stop member. The blades can be movable in the slots during shaving. The stop member is provided on the plastic block. Different slots can have stop members at different heights. The slots can be parallel or nonparallel.
In another aspect the invention features, in general, a method of making a shaving razor that includes providing a plurality of elongated metal razor blades having cutting edges and first and second longitudinal ends, and securing the first longitudinal ends to a first plastic block and the second longitudinal ends to a second end block at locations on the first and second plastic block such that the cutting edges define a shaving surface, and the blades and blocks provide an integrated blade subassembly.
Particular embodiments of the invention may include one or more of the following features. In particular embodiments the integrated subassembly is inserted into a recess in a housing of a shaving razor. The cutting edges are moved to contact a stop member on the housing. A biasing member secured to the housing to bias the cutting edges against the stop member. The integrated blade subassembly unit is held in the housing by a snap-fit connection. The recess can be open to the top, with the integral blade subassembly being lowered into the recess, or the recess can open to the bottom, with the integral blade subassembly being raised into the recess.
Embodiments of the invention may include one or more of the following advantages. Automated assembly of razor blade cartridges can be simplified by installing all of the blades as a unit in a single step. The geometry of the cutting edges with respect to each other can be set prior to assembly into a housing and tightly controlled and varied, if desired. The subassembly of blades can be removably mounted in a housing and replaced with a new subassembly as the blades become spent, thereby decreasing the parts that are disposed and reusing more parts. Also, integrated blade subassemblies can be manufactured with a variety of different blade geometries, with, e.g., different blade tangent angles, exposures, and/or spans, and the different subassemblies can all be used with a common design for the rest of the cartridge into which they are inserted, simplifying part count and tooling at the same time that a variety of different geometries can be easily implemented.
Other advantages and features of the invention will be apparent from the following description of particular embodiments thereof and from the claims.
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Each blade 14 includes an elongated cutting member 26 having cutting edge 28 and elongated support 30 to which cutting member 26 is attached by spot welds 32. Elongated support has an angled section along its length, with a short upper portion 34 and longer base portion 36. The longitudinal ends 38 of base portion 36 are received in slots 40 in plastic end blocks 24. Each longitudinal end has a hole 42.
Alternatively, the elongated cutting members could be one-piece constructions having a cutting edge portion and an integral bent base portion, as shown, e.g., for one-piece complex member 39 in
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Other embodiments of the invention are within the scope of the appended claims.
There can be any number of blades, (e.g., 2, 3, 4, 5, 6, 7, etc). Two-, three- and four-blade subassemblies 100, 102, 104, respectively, are shown in