Cap for razor blade assembly adapted to receive an extra element

This invention relates to a razor blade assembly and particularly to a cap for blade assembly in which a rectangular shaving aid has been attached by means of deformable positioning means extending upward from the cap.

FIELD OF THE INVENTION 
This invention relates to a razor blade assembly and particularly to a cap 
for a blade assembly in which a shaving blade has been attached. 
BACKGROUND OF THE INVENTION 
U.S. Pat. No. 4,170,821 issued to Booth on Oct. 16, 1979 discloses a solid 
water soluble shaving aid incorporated as a strip attached to a disposable 
razor blade cartridge. Cartridges having such shaving aids attached to the 
cap are currently marketed with the aid being mixed in polystyrene. 
Currently, polyethylene oxide is the shaving aid preferred. Examples of 
cartridges with these soluble shaving aids sold by as "Atra Plus.TM." by 
Gillette Company, Boston, Mass. and "Ultrex Plus.TM." sold by 
Warner-Lambert Company, Morris Plains, N.J. (Cartridges as used herein are 
blade assemblies sold as individual items for attachment to a separate 
handle. Blade assembly is used generically to include both the cartridge 
and that part of a unitary disposable razor other than the handle. The 
cartridge and blade assembly include at least one blade, a seat for the 
blade, a guard bar extending from the seat, and a cap and means for 
separating the blades, if more than one blade is used, and means for 
maintaining blade position.) 
While location of the lubricating strip on the cap has proven to be 
desirable because of the liberation of lubricant with each razor stroke, 
the attachment of the plastic strip in which the polyethylene oxide 
lubricant has been impregnated, has proven to be difficult. Both the "Atra 
Plus" and the "Ultrex Plus" cartridge have the lubricating strip 
adhesively secured to the cap of the blade assembly. Adhesive securement 
requires the separate steps during the manufacturing process of contacting 
the cap with adhesive, precisely locating the lubricating strip to be in 
registery with the adhesive and, finally, clamping the strip to insure 
proper adhesive bonding. Not only do these additional steps dramatically 
slow the process but the cost of the adhesive and the problems associated 
in working with a necessarily quick-drying plastic bonding adhesive with a 
volatile organic solvent add unnecessary time and complexity to what is 
otherwise a ultra high speed manufacturing process. 
SUMMARY OF THE INVENTION 
This invention provides a shaving assembly and particularly a shaving 
assembly cap particularly adapted to receive and clamp a lubricating strip 
without the use of adhesive. The cap, according to this invention, 
utilizes projections which extend upward from the cap at both the front 
and rear portion of the cap defining a pocket which receives the 
lubricating strip. After the strip has been positioned, the projections 
which have sufficient deformability and plasticity, are then bent over the 
strip to maintain it without the defined space between the projections. 
Bosses are present at each side of the strip after insertion to prevent 
lateral displacement. It is the bosses and projections, which, in 
combination, define the strip receiving pocket.

As shown in FIGS. 1 and 4 the razor cap 10 of blade assembly B has a back 
surface 11 and a front surface 13 and sides 15a and 15b. As shown in FIG. 
1, the lubricating strip 20 is partially overlaid by projection 16 which 
extends along the entire length of the rear portion of the strip 20. The 
lubricating strip 20 is also held in place and the front portion of the 
razor cap by tabs 12a, 12b and 12c positioned as shown in FIG. 1. Bosses 
14a and 14b positioned inward along the sides 15a and 15b respectively 
prevent lubricating strip 20 from shifting laterally either during 
insertion or use. Tapering downward from the front of the cap 13 and 
extending from sides 15a and 15b respectively are legs 15c and 15d. 
Positioned between the legs 15c and 15d adjacent and partially underlying 
the front portion of the cap 13 is a top blade 19 and a bottom blade 18 
with the bottom blade 18 extending outward farther than the top or cap 
blade 19. Ribs 21 extend toward guard bar 22 extend outwardly beneath the 
blades 18 an 19 as projections below and at part of, a blade seat (not 
otherwise shown). These ribs 21 extend parallel to the legs 15c and 15d 
and join guard bar 22 which is designed to protect the face of the shaver 
during the shaving operation itself. 
The configuration of the front projections, i.e., the 3 tabs illustrated in 
FIG. 1 is a currently preferred clamping configuration for providing 
secure multi-position clamping along the front portion of the cap with 
maximum exposure of the lubricating strip. It is also possible to use this 
multitab configuration for the rear projection but, due to the nature of 
the forces exerted during shaving, multiple tabs are not as important in 
the rear portion of the cap. The blade assembly depicted in FIG. 1 as 
illustrated in FIG. 2 is held in place by staking means 17, the spacing of 
which can be seen by reference to FIG. 2 and FIG. 3. 
The particular method of maintaining the assembly configuration is not part 
of this invention and any of the well known means can be utilized 
including staking with positioning as shown in FIG. 3 with stakes 
extending either downward from the cap or upward from the seat or 
combinations thereof. Staking can occur upwardly from the seat, engaging 
the bottom or seat blade and downwardly from the cap engaging the cap 
blade with the stakes terminating at the opposite blade maintaining the 
position of the components by upward and downward pressure against these 
blades. Other common assembly means can also be used. For example the cap 
and seat may be formed of resilient fingers acting as leaf springs and 
this method may be used alone or in conjunction with assorted stakes and 
detents to maintain relative positioning of the components of the blade 
assembly, the particular choice of assembly maintenance means is well 
known by those skilled in the art. 
FIG. 2 is illustrative of the relationship between the staking tab and 
lubricating strip and their position and indicates that, at the place 
where tab 12c is positioned, in cross section, the tab 12c and 16 overlay 
the lubricating strip 20 as shown therein and positioned directly above 
staking means 17. 
According to this invention it is preferred that the projection 16 on the 
back 11 of cap 10 be essentially a solid continuous strip. Shaving itself 
exerts a backward pressure on the projection area 16 and the continuous 
strip offers better resistance than a single tab or a plurality of tabs 
although other configurations can of course be used as long as they extend 
essentially along the entire length of the back 11 of cap 10. 
Referring now to FIG. 3 in which a second embodiment of the cap is shown. 
This Fig. does not show the presence of the lubricating strip 20 which is 
inserted in the central part of the cap 25 but does illustrate the 
receiving pocket formed by the bosses and the projections. FIG. 3 shows a 
continuous projection 12 positioned along the front portion 13 of the cap 
10 and also shows the positioning of the cap face at an angle relative to 
the plane formed by the bottom of cap sides 15a and 15b. It is currently 
preferred that the lubricating strip be angled with respect to the cap 
bottom surface at an angle up to about 30.degree. (see angle .phi. in FIG. 
2) so that it correlates with contact shaving angle of the blades and the 
blade assembly. The shaving angle can vary depending upon whether there is 
a single or multiple blade or whether the razor is designed for maximum or 
minimum exposure. Although these features are well known within the art 
and are not part of this invention. 
The lubricating strip is added to the cap illustrated in FIG. 3 by 
positioning the cap over the pocket formed by bosses 14a and 14b 
projections 16 and 12 and the central portion of the cap 25 defined by 
these projections. Once the strip 20 is in place, as illustrated in FIG. 
1, the projections 16 and 12 regardless of their shape are bent inward 
toward each other and overlay a portion of the cap thereby serving to 
retain it along with the bosses which could be extended and bent over at 
the ends, however, because the forces exerted during shaving are not 
directed along the length of the blade, the bosses need not be bent but 
need merely serve as abuttments.