The present invention relates to shaving razors and more particularly to shaving razor blade units having a self leveling trimmer blade.
In recent years shaving razors with various numbers of blades have been proposed in the patent literature and commercialized such as the three-bladed Mach 3™ razor and the five bladed Fusion™ razor by The Gillette Company.
Increasing the number of blades on a shaving razor generally tends to increase the shaving efficiency of the razor and provide better distribution of compressive forces on the skin but it can also tend to increase drag forces, reduce maneuverability, and reduce the ability to trim, e.g., sideburns or near the nose. To solve this problem an extra blade can be mounted at the rear of the razor housing for trimming.
Short hairs are typical of hair growth of approximately twenty-four hours. The edge of a trimming blade on the razor is able to cut the short hair at an optimum angle if the blade unit is oriented at the appropriate cutting angle during use. However, it is unlikely that a user has any knowledge that the trimmer unit has been designed with an optimum cutting angle in mind. What's more, even if they where aware, it would be difficult if not impossible to position the razor so that the trimmer blade is oriented in the optimum cutting angle. As a result, not all consumers are getting the best results from their trimmer.
It is therefore desirable to provide a trimming element that presents the blade to the skin and maintains an optimum cutting angle during use to maximize efficiency.
In one aspect, the invention features, in general, a shaving blade unit having a self leveling trimmer assembly. The shaving blade unit comprises a housing having a front, a back and two sides extending from the front to the back with one or more shaving blades disposed within the housing between the front, back and two sides. A trimming assembly is pivotally mounted at the back of the housing. The trimming assembly comprises a trimming blade having a cutting edge, wherein the trimming assembly rotates and presents the cutting edge at an optimal skin to blade cutting angle and maintains the cutting angle during use to maximize cutting efficiency.
In one embodiment, the trimming assembly comprises a frame pivotally mounted to a pivotal interface at the back of the housing. The pivotal interface can comprise pins disposed at the back and on opposite sides of the housing where the frame is connected to the pins via c-shaped members disposed on the ends of the frame. The pivotal interface can also comprise pivot assemblies on the frame such as ball shaped or cone shaped pivots on opposing ends of the frame that interface with similarly shaped apertures in the housing. In one embodiment, the pivot assemblies comprise shell bearing pivots on the ends of the frame that interface with shell shaped apertures in the housing. In another embodiment the pivot assemblies comprise torsion elastomers disposed on the ends of the frame that interface with slots in the housing.
The frame supports a trimming blade having a cutting edge, a trimming guard disposed in front of the cutting edge of the trimming blade and a trimming cap disposed behind the cutting edge of the trimming blade. The trimming guard and trimming cap include skin contact points which contact the skin of the user during use. The optimal cutting angle of the trimming blade is set at an angle relative to a plane tangent to the trimming guard skin contact point and the trimming cap skin contact point. Since the frame is designed to rotate, once contact is made with one of the two skin contact points, the frame rotates so that both skin contact points make contact. As a result, the trimming blade is oriented in the optimal cutting angle regardless of the approach angle of the trimming assembly to the skin.
In another embodiment, the housing includes a primary guard at the front of the housing and a primary cap at an upper surface at the back of the housing. The one or more shaving blades are disposed within the housing between the primary guard and the primary cap. For this embodiment, the self leveling trimmer blade is disposed behind the primary cap.
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as forming the present invention, it is believed that the invention will be better understood from the following description taken in conjunction with the accompanying drawings.
a is a perspective view of the frame portion of the trimming assembly.
b is a top view of the frame portion of the trimming assembly.
c is a front side view of the frame portion of the trimming assembly.
a and 9b are perspective views of the bottom of the razor unit showing the trimming assembly removed from the razor and the pivotal interface comprising cone shaped pivots on the ends of the frame interfacing with cone shaped apertures on the housing of the razor.
a, 11b and 11c are end views of the frame of the razor unit showing a pivotal interface comprising torsion elastomers on the ends of the frame interfacing with slots on the housing of the razor.
The shaving blade unit with the self leveling trimmer according to the present invention will be described with reference to the following figures which illustrate certain embodiments. It will be apparent to those skilled in the art that these embodiments do not represent the full scope of the invention which is broadly applicable in the form of variations and equivalents as may be embraced by the claims appended hereto. Furthermore, features described or illustrated as part of one embodiment may be used with another embodiment to yield still a further embodiment. It is intended that the scope of the claims extend to all such variations and equivalents.
Referring to
Referring to
As illustrated in
As illustrated in
The frame 42 can rotate clockwise and counterclockwise providing an angular range of rotation of about 32°. The rotation of the frame 42 can be limited by the interaction of the trimmer guard 46 and trimming cap 48 with the housing 20. For instance, as shown in
In manufacture, frame 42 can be cut and formed from sheet metal, comprise a substrate wire cut from a block of metal, or comprise a molded plastic substrate. Trimming blade 44 is placed against interior surface of intermediate wall 56 where it is secured by spot welds. The frame 42 is placed on the back of the housing 20 by sliding it forward over the rear of housing 20 with fulcrum 64 on the brackets 60 of the frame 42 mounting on a pivotal interface on the rear of housing 20. For the embodiment shown in
In alternate embodiments shown in
In other embodiments, the pivoting motion of the frame 42 is dependent upon the design of the fulcrums 64 included on the brackets 60 of the frame 42. For instance, in the embodiment shown in
In another embodiment shown in
In another embodiment shown in
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
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