GB2066133A - One-piece razor handle for pivotable cartridge - Google Patents

Abstract

A one-piece, open frame, moulded plastic razor handle has diverging upper arms 34 with cartridge-engaging ends that can be spread apart. An L-shaped cantilever beam cam follower has a rigid base 42 extending inwardly from the inside surface of one of the arms, and a resilient cantilever portion extending from the base toward a pivotable razor cartridge engaged by the handle. The cantilever portion has an edge 48 that engages the cam surface of the pivotable razor cartridge. <IMAGE>

Description

SPECIFICATION One-piece razor handle for pivotable cartridge This invention relates to wet shaving systems using blade cartridges, and particularly to razor handles adapted for engaging blade cartridges that are pivotable about their major axis during shaving.

Most wet shaving systems available today use blade cartridges rather than blades alone as the replaceable elements of the system. The cartridges allow precise location and orientation of the blade in its support structure, and are even more necessary for the use of dual blade systems, where two cutting edges are located in a cartridge in a precise relationship.

A number of techniques are used for attaching cartridges to razor handles. Furthermore, some techniques include the significant addition of attaching the cartridge to the handle in a way that allows the cartridge to pivot, in a controlled way, about its major axis. Pivotal attachment of the cartridge allows the blade mounted in the cartridge to follow skin surface contours independently of the handle orientation. The cartridge is pivotable between limits, and ordinarily is biased toward a preferred angular position vis-a-vis the handle.

In some cases, a portion of the cartridge has a camming surface that is adapted to meet a cam follower on the handle when the cartridge is attached. For example, Nissen et al (U. S. Patent No: 4,083,104) shows a pivotable blade cartridge in which a camming surface is engaged by a spring biased cam follower. The camming surface slides along the front of the cam follower, and the variation in the camming surface acts on the follower in a generally horizontal way. The cam follower shown in the patent is a mechanism of several parts.

Trotta (U. S. Patent No: 4,094,063) shows another pivoting cartridge and handle combination. There the entire combination is disposable, allowing some simplification of the assembly, since there need be no provision for disengaging the cartridge from the razor handle after it is used. Jaws with inwardly extending fingers for pivotally engaging apertures in the cartridge are resiliently expandable to engage the cartridge. In other words, the cartridge is "snapped" into engagement with the handle jaws. At the head of the handle is a horizontal bridge mounted on legs projecting from the handle. The bridge is a resilient cam follower that exerts biasing force on the cartridge camming surface as the camming surface slides vertically across it, moving it (like the Nissen device) generally horizontally. In a South African application corresponding to this U. S.

patent, the bridge is additionally shown in a form in which it is split.

In U. S. Patents No: 3,938,247 (Carbonell et al) and No: 3,935,659 (Terry et al) cartridges are shown that are engaged by cantilever springs to control the pivotal movement of the cartridge.

It is desirable to simplify the razor handle used with blade cartridges, and to simplify the mechanisms for engaging the cartridge and particularly for biasing the pivotal movement of the cartridge. In our copending application corresponding to U.S.S.N.

108,742 a one-piece razor handle is described that has diverging upper portions which respond to squeezing the handle by spreading apart so that cartridge-engaging fingers at the end of the upper portions disengage from the cartridge. It would be desirable to use such a razor handle for pivoting cartridges, but the movement of both upper portions makes it difficult to impose a centrally located cam follower. Similarly, suitable handles in which the diverging upper portions may be forced apart as by a mechanical spreading force therebetween, would also present the same problem.

Accordingly, it is an object of the invention to provide a razor handle that is simple and easy to attach to a pivotable razor blade cartridge, which has a simple, sure and reliable cam follower arrangement for the camming surface provided on pivotable razor cartridges, and which is relatively simple and inexpensive to manufacture.

According to the present invention we provide a one-piece razor handle for pivotal engagement of a razor blade cartridge having a camming surface for engagement with a cam follower, said razor handle comprising: a body portion having a longitudinal axis and adapted to be held by a shaver, said body portion having a neck region, and a pair of diverging arms extending upwardly from said neck region, said diverging arms including means for engaging said blade cartridge, wherein the improvement comprises said handle further including: a cantilever beam extending from a location on one of said diverging arms remote from said neck region toward said camming surface for camming engagement with said camming surface, said cantilever beam being resiliently deflectable in a direction generally axially of said body portion.

Reference is now made to the drawings, in which: Figure 1 is a rear perspective view of a razor cartridge and a razor handle constructed according to the invention; Figure 2 is a detailed side view, partially in section, of the razor cartridge in engagement with the razor handle cam follower; and Figure 3 is a view like that of Figure 2, showing the cartridge pivoted upwardly.

Figure 1 shows a typical pivotable razor blade cartridge 10, and a razor handle 12 constructed according to the invention. The cartridge rear surface 14 includes a pair of horizontally spaced, vertical wall members 16 projecting rearwardly.

Each wall member 16 has a horizontally extending aperture 18 facing outwardly for engagement by inwardly extending jaws of a razor handle.

The cartridge rear surface 14 also includes a central rearwardly projecting wall 20 with a camming surface 22 facing rearwardly. The camming surface 22 is most shallow, or extends most forward, at a horizontal mid line 24 and extends gradually more rearwardly on either side of the mid line 24.

The razor handle 12 is a single piece open frame, molded from a plastic that provides some resiliency in the frame elements. The handle 12 includes two spaced apart vertical side walls 26 rising from a solid base portion 28. Above the base 28, the walls 26 form a slot 30 between them, the slot 30 terminating in the upper part with a neck 32 extending from one side wall 26 to the other. The wails 26 are resiliently squeezable into the slot 30 by virtue of the characteristics of the plastic material used to form the handle.

Above the neck 32, the razor handle walls 26 diverge to form jaw-like upper wail portions 34 terminating with cartridge engaging, horizontally inwardly extending fingers 36 for engaging the apertures 18 of the blade cartridge 10. The upper wall portions 34 are responsive to squeezing of the handle side wall lower portions 38. When the lower portions 38 of the side walls 26 are squeezed together in the direction indicated by the arrows 39, the handle neck 32 acts like a fulcrum so that the upper portions 34 of the side walls diverge in the direction indicated by the arrows 41. In this way the razor cartridge 10 can be attached and detached to the handle 12. Alternatively, particularly if the side walls of the handle are not so flexible, a machine may spread the jaws and fingers.

A cam follower 40 is also formed as part of the razor handle 12. The cam follower 40 is a generally L-shaped portion of the razor handle. It has a base portion 42 extending horizontally inwardly parallel to the cartridge 10 from the inside surface 44 of one of the side wall upper portions 34. The base portion 42 is joined to a central portion 46 extending generally horizontally toward the cartridge 10 and terminating in a cam follower edge 48. The cam follower edge 48 is located so that when the cartridge 10 and handle 12 are engaged via the handle fingers 36, the edge 48 abuts the cam surface 22 at its mid line 24 (see Figure 2). The line of engagement of the cam follower edge 48 and cam surface 22 at the mid line 24 is behind the pivot axis of the cartridge 10, the axis being defined by the location of the cartridge engaging fingers 36.The cam follower40 is resilientlyflexibleabouta horizontal axis aligned generally with the base portion 42 so that the cam follower edge 48 is movable in a generally vertical direction. The edge 48 applies a pre-load biasing force to cam surface 22 to insure that the cartridge 10 assumes a neutral angle in the absence of shaving forces.

The razor handle 12 of this embodiment is used to engage the blade cartridge 10 by pinching, or squeezing, the lower portions 38 of the handle walls 26 at a point between the handle neck 32 and the handle base 28, preferably midway between the two.

This spreads the wall upper portions 34 as the neck 32 acts like a fulcrum. The razor handle 12 is positioned relative to blade cartridge 10 so that the pair of cartridge apertures 18 is between the fingers 36 projecting inwardly from the spread apart wall upper portions 34. When the handle walls 26 are released, the upper portions 34 return to their original position, with the fingers 36 now inserted into the apertures 18.

The cartridge 10 is pivotable about an axis extending through the fingers 36 when it is engaged in the manner set out above. However, in its engaged position the cartridge is also affected by the relationship between its cam surface 22 and the cam follower 40 of the handle 12. The edge 48 of the cam follower abuts the cam surface 22 at its shallow mid line 24. Without any other forces acting on the cartridge, the cam follower edge maintains the cartridge at a neutral position corresponding to the relaxed position of the cam follower 40. During shaving, however, forces are generated that cause the cartridge 10 to pivot about the handle fingers 36.

The forces are transmitted to the cam follower edge 48 by the cam surface 22, and the cam follower 20 is deflected accordingly. Thus, as shaving produces an upward force on the front of the cartridge (see Figure 3), the cam surface 22 tends to deflect the cam follower edge 48 vertically downwardly. The resilience of the cam follower 40 urges it to resume its original position, and if the changing contour of the surface being shaved changes the nature of the forces acting on the cartridge 10, the cam follower 40 will urge the cartridge back toward its neutral position.

With this arrangement of the cam surface 22 and the cam follower 40, the pivoting motion of the cartridge 10 is transformed into vertical motion of the cam follower edge 48. The base portion 42 of the cam follower is relatively non-resilient and immovable because of its connection to the razor handle upper portion 34, and because its cross-sectional area is made large enough. The central portion 46, on the other hand, is relatively resilient because its cross-section is thin and because it is a distance from the handle to which it is attached, in a cantilever arrangement.

The configuration of the cam follower 40 allows its use with the open, spreadable upper portions 34 of the razor handle 12. The open framework of the handle 12 dictates against having a "head" of the handle on which a cam follower can be mounted. A head would interfere with the spreadability of the handle upper portions. The cam follower 40 of the invention is mounted as a cantilever beam on a side of one of the diverging wall upper portions 34, so that the upper portions 34 may be spread out easily by squeezing the wall lower portions 38 without interference from structure supporting a cam follower.

Claims (6)

1. A one-piece razor handle for pivotal engagement of a razor blade cartridge having a camming surface for engagement with a cam follower, said razor handle comprising: a body portion having a longitudinal axis and adapted to be held by a shaver, said body portion having a neck region, and a pair of diverging arms extending upwardly from said neck region, said diverging arms including means for engaging said blade cartridge, wherein the improvement comprises said handle further including: a cantilever beam extending from a location on one of said diverging arms remote from said neck region toward said camming surface for camming engagement with said camming surface, said can tilever beam being resiliently deflectable in a direction generally axially of said body portion.

2. A one-piece handle as claimed in Claim 1, having a single cantilever beam extending from one of said diverging arms.

3. A one-piece handle as claimed in Claim 1 wherein said beam comprises: a first portion extending inwardly from said location, generally parallel to said blade cartridge, and a second portion, integrally formed with said first portion, extending transversely from said first portion toward said cartridge camming surface.

4. A one-piece handle as claimed in Claim 1 wherein said cantilever beam includes a sustantially rigid base portion extending from one of said diverging arms and a substantially vertically resilient cantilever portion extending from said base portion toward said cartridge camming surface.

5. A one-piece razor handle for pivotal engagement of a razor blade cartridge having a camming surface for engagement with a cam follower, said razor handle comprising: a body portion having a longitudinal axis adapted to be held by a shaver, said body portion having a neck region, a pair of diverging arms extending upwardly from said neck region, said diverging arms including means for engaging said blade cartridge, and a single cantilever beam, said beam comprising: : a base portion extending inwardly from a location on one of said diverging arms remote from said neck region, generally parallel to said blade cartridge, and a cantilever portion, integrally formed with said base portion, extending transversely from said base portion toward said cartridge camming surface, and terminating in a forward edge for camming engagement with said camming surface, said cantilever beam being resiliently deflectable in a direction generally axially of said body portion.

6. A one-piece razor handle substantially as herein described with reference to and as shown in the accompanying drawings.