1. Technical Field
This invention relates to shaving devices in general, and to shaving devices that utilize apparatus for biasing one or more razor blades toward the surface being shaved.
2. Background Information
Modern safety razors include a plurality of blades disposed within a cartridge that is pivotally or rigidly mounted on a handle. Some safety razors have a disposable cartridge for use with a reusable handle, while others have a handle and cartridge that are combined into a unitary disposable. Although a variety of razor cartridge configurations exist, most include a frame made of a rigid plastic that includes a seat and a cap. Cartridges often include a guard disposed forward of the blades. The guard and the cap orient the position of the person's skin relative to the blades to optimize the shaving action of the blade. Some cartridges include a comfort strip comprised of shaving aids (e.g., lubricating agents, drag reducing agents, depilatory agents, cleaning agents, medicinal agents, etc.) to enhance the shaving process. The terms “forward” and “aft”, as used herein, define relative position between features of the safety razor (i.e., razor assembly). A feature “forward” of the razor blades, for example, is positioned so that the surface to be shaved encounters the feature before it encounters the razor blades, if the razor assembly is being stroked in its intended cutting direction (e.g., the guard is forward of the razor blades). A feature “aft” of the razor blades is positioned so that the surface to be shaved encounters the feature after it encounters the razor blades, if the razor assembly is being stroked in its intended cutting direction (e.g., the cap is disposed aft of the razor blades).
The comfort and performance provided by a particular razor cartridge are critical to the commercial success of the razor. Improvements that benefit razor comfort, performance, and ease of use, however significant or subtle, can have a decided impact on the commercial success of a razor. For example, most razors include a guard bar to orient the skin to be shaved in a favorable position for the one or more razors disposed aft of the guard. With force applied by the user, the guard bar draws the skin taut to optimize the orientation of the skin relative to the cutting edges of the one or more razor blades. With most presently available razor cartridges, however, the normal force that is desirable to draw the skin taut can also be undesirable if applied too strongly. Excessive force will put the cutting edges of the razor blades too close to the skin and thereby increase the chance the skin will be cut or irritated.
What is needed, therefore, is a razor cartridge that can be used safely for a large range of normal forces applied by the user.