[0001] This invention relates to shaving devices and concerns a safety razor blade unit
having at least one blade with a cutting edge which is moved across the surface of
the skin being shaved by means of a handle to which the blade unit is attached. The
blade unit may be mounted detachably on the handle to enable the blade unit to be
replaced by a fresh blade unit when blade sharpness has diminished to an unsatisfactory
level, or it may be attached permanently to the handle with the intention that the
entire razor be discarded when the blade or blades have become dulled. Razor blade
units generally include a guard which defines a surface for contacting the skin in
front of the blade(s) and a cap for contacting the skin behind the blade(s), the cap
and guard serving important roles in establishing the so-called "shaving geometry",
i.e. the parameters which determine the blade orientation and position relative to
the skin during shaving. The present invention is especially concerned with the guard
and/or cap of a razor blade unit.
[0002] As a preliminary step prior to shaving it is common to apply a shaving preparation
to the skin, such as shaving soap or the like to facilitate the shaving operation.
One effect of the shaving preparation, for example, is to lubricate the skin to enable
the razor to slide more easily over the skin. In some situations, however, the skin
is not prepared as well as it might be. Furthermore, at the end of shaving most- of
the preparation will have been removed. Therefore, it can be advantageous to provide
the razor with a means for delivering a shaving enhancement composition or medium
during shaving. Thus, it is known to provide a blade unit with a strip of material
from which a lubricant is very gradually leached out during shaving. The benefits
of such a lubricating strip have been well proven, but the active materials which
can be incorporated in them is limited, e.g. by the manufacturing process, and the
rate at which the lubricant is discharged is so low that an effective preparation
of the skin before shaving is still needed. There have also been proposed razors which
include a chamber containing a liquid shaving preparation, and a system for discharging
the liquid onto the operative parts of the razor by squeezing a sponge impregnated
with the liquid by applying finger pressure. However, there still remains a need for
a razor adapted to dispense a shaving aid product gradually throughout the useful
life of the razor blade unit, without requiring special attention by the user, such
as to refill a reservoir or to cause the product to be discharged when required.
[0003] According to the present invention there is provided a safety razor blade unit having
at least one elongate blade, and a skin engaging member defining a surface exposed
for contact with the skin during shaving, said member including a multiplicity of
pockets four holding respective portions of shaving enhancement product, said pockets
being distributed longitudinally and laterally over the skin contacting surface and
each being open at the surface.
[0004] A skin engaging member provided according to the invention may allow for the dispensing
of materials which can not be included in prior art lubricating strips, e.g. because
they can not withstand the manufacturing process. The shaving enhancement product
may be a formulation, such as semi-solid gel, which has been designed to have the
desired solubilizing properties, and is conveniently retained in the pockets due to
the properties of the product. The product may be a viscous fluid, or a gel, and may
be of a nature to be miscible with water, which is generally present during shaving,
or to dissolve in water, to render the product more fluid for discharge from the pockets.
[0005] In order to provide adequate supply of shaving enhancement product to last the useful
lifetime of the blade unit, the pockets can communicate at the inner ends with a reservoir
chamber containing the shaving enhancement product to be dispensed via the pockets.
[0006] The pockets should be disposed in an array with sufficient density of packing to
ensure satisfactory application of product during shaving. A width of surface between
the adjacent pockets of 5% to 100% of the maximum transverse dimensions of the pockets
should be adequate while retaining a sufficiently well defined skin contacting surface.
[0007] In a preferred construction the pockets are cylindrical, i.e. have smoothly curved
side walls, and conveniently the pockets are right circular cylindrical with their
axes substantially perpendicular to the skin contacting surface. However, other shapes
are also possible, such as hexagonal or elliptical in cross section. The depth of
the pockets is less than the pocket diameter, e.g. approximately equal to the pocket
radius, and the thickness of material between adjacent pockets is less than the pocket
radius.
[0008] The pockets are preferably formed in a front wall of a chamber for holding a supply
of a fluid shaving enhancement product, each of the pockets communicating with the
chamber through a restricted opening to control flow of product into the pockets and
hence release at the skin contacting surface.
[0009] The skin engaging member can be the guard of the blade unit or it can be another
member, such as the cap.
[0010] A better understanding of the invention will be gained from the following detailed
description of an embodiment, reference being made to the accompanying drawings, in
which:
Figure 1 is a cut away perspective view of a razor blade unit according to the invention;
Figure 2 is a transverse cross section through the blade unit.
[0011] The safety razor blade unit shown in the drawings comprises a pair of blades 1, 2
mounted in tandem in a supporting frame, a guard 3 fastened to the frame and defining
a hollow reservoir chamber 4, and cap 5 e.g. in the form of a strip of lubricating
material carried by the frame behind the blades.
[0012] The guard includes an upper wall 8 with an exposed surface 9 which is arranged to
contact the skin during shaving. Within this wall is formed a multiplicity of pockets
10 positioned in a regular array extending over the length and width of the skin contacting
surface. The pockets are disposed in a plurality of longitudinal rows, and in the
shown example there are three rows with the pockets in adjacent rows longitudinally
off set to permit the pockets to be closely spaced. The pockets are of circular configuration
and in the illustrated embodiment all have the same diameter.
[0013] Each pocket 10 is in communication with the reservoir chamber 4 through a hole 12
shown to be of restricted area at the inner end of the pocket. The through flow area
of the hole is selected to allow shaving enhancement product contained in the chamber
4 to flow at a controlled rate into the pockets where the product collects and remains
held e.g. under the surface tension properties of the fluid product, ready to be discharged
during shaving. The restricted hole also serves to obstruct the passage of the shaving
aid product from the pocket back into the reservoir chamber, so that the pockets remain
charged with product. In practice the reservoir chamber will contain sufficient volume
of shaving aid product to last the full useful lifetime of the blade unit, that is
until the blades have become dulled.
[0014] The shaving aid product preferably has lubricating property, but it may have, either
alternatively or in addition, other, e.g. moisturizing properties considered beneficial
during shaving. It will have adequate fluidity to enable the product to pass from
the reservoir chamber into the pockets, and adequate viscosity and surface tension
characteristics to be held in the pockets without flowing freely out from the pocket
openings, and to be dispensed gradually during shaving, e.g. upon being made more
fluid by contact with water, when the guard surface slides over the skin during shaving.
[0015] It is not an essential feature that the pockets should be supplied with shaving enhancement
product and it is within the ambit of the present invention for the pockets to be
shaped and dimensioned to collect a shaving enhancement product applied to the skin
during one time of shaving and to retain that product until the next time of shaving,
e.g. to provide improved lubrication during the initial stages of the subsequent shave.
[0016] Modifications are of course possible without departing from the underlying inventive
concept. For example, the member incorporating the pockets filled with shaving aid
product could be made of a resilient material so that the member will flex slightly
during shaving to encourage product to flow from the pockets. In addition to the benefits
mentioned above the apertured member with the pockets may have a beneficial tactile
influence upon the skin.
1. A safety razor blade unit including at least one elongate blade, and a skin engaging
member extending longitudinally of the blade(s), said member having a skin contacting
surface exposed for contact with skin of a user during shaving, characterized in that the skin engaging member includes a multiplicity of openings at the skin contacting
surface, said openings being adapted to discharge respective portions of a shaving
enhancement product therefrom during shaving, said openings being distributed along
the skin contacting surface and across the width thereof to span substantially the
whole of the area of the skin contacting surface.
2. A safety razor blade unit including at least one elongate blade, and a skin engaging
member extending longitudinally of the blade(s) and defining a surface exposed for
contact with the skin during shaving, said member including a multiplicity of pockets
for holding respective potions of a shaving enhancement product, each of said pockets
opening at the skin contacting surface, said pockets being distributed along the surface
and across the width thereof forming an array spanning substantially the whole of
the area of the skin contacting surface.
3. The safety razor blade unit of claim 1, characterized in that the multiplicity of openings are arranged to receive the shaving enhancement product
from a common source.
4. The safety razor blade unit of claim 2, characterized in that the multiplicity of pockets are arranged to receive the shaving enhancement product
from a common source.
5. The safety razor blade unit of claim 3, characterized in that at least some of the multiplicity of openings communicate with the common source
containing shaving enhancement product to be dispersed via the openings.
6. The safety razor blade unit of claim 4, characterized in that at least some of the multiplicity of pockets communicate with the common source containing
shaving enhancement product to be dispersed via the pockets.
7. The safety razor blade unit of claim 5, wherein each opening communicates with the
common source.
8. The safety razor blade unit of claim 6, wherein each pocket communicates with the
common source.
9. The safety razor blade unit of claim 7, wherein the openings are formed in a wall
member partially confining the common source.
10. The safety razor blade unit of claim 8, wherein the pockets are formed in a wall member
partially confining the common source.
11. The safety razor blade unit of claim 1, wherein the openings have smoothly curved
side walls.
12. The safety razor blade unit of claim 2, wherein the pockets have smoothly curved side
walls.
13. The safety razor blade unit of claim 11, wherein the openings are cylindrical with
the axes thereof substantially perpendicular to the skin contacting surface
14. The safety razor blade unit of claim 13, wherein the openings are right circular cylindrical.
15. The safety razor blade unit of claim 14, wherein the openings have a depth not greater
than the opening diameter.
16. The safety razor blade unit of claim 12, wherein the pockets are cylindrical with
the axes thereof substantially perpendicular to the skin contacting surface.
17. The safety razor blade unit of claim 16, wherein the pockets are right circular cylindrical.
18. The safety razor blade unit of claim 17, wherein the pockets have a depth not greater
than the pocket diameter.
19. The safety razor blade unit of claim 1, wherein the openings are positioned in a plurality
of longitudinal rows.
20. The safety razor blade unit of claim 19, wherein the openings of adjacent rows are
longitudinally offset and overlap.
21. The safety razor blade unit of claim 2, wherein the pockets are positioned in a plurality
of longitudinal rows.
22. The safety razor blade unit of claim 21, wherein the pockets of adjacent rows are
longitudinally offset and overlap.
23. The safety razor blade unit of claim 1, wherein the openings have depth at least 50%
of the maximum transverse dimension of the openings.
24. The safety razor blade unit of claim 23, wherein the openings have depth not greater
than the transverse dimension of the openings.
25. The safety razor blade unit of claim 1 or 2, wherein the skin engaging member comprises
a resilient material to flex during shaving and exert traction force on the skin surface
being shaved.
26. The safety razor blade unit of claim 1, wherein a thickness of surface between adjacent
openings is less than 50% of the maximum transverse dimension of the openings.
27. The safety razor blade unit of claim 1, wherein there at least three longitudinally
extending rows of openings.
28. The safety razor blade unit of claim 1 or 2, wherein the skin engaging member occupies
a position of a guard surface in advance of the at least one blade.
29. The safety razor blade unit of claim 1 or 2, wherein the skin engaging member occupies
a position of a cap surface behind the at least one blade.
30. The safety razor blade unit of claim 2, wherein the pockets have depth at least 50%
of the maximum transverse dimension of the pockets.
31. The safety razor blade unit of claim 30, wherein the pockets have depth not greater
than the transverse dimension of the pockets.
32. The safety razor blade unit of claim 2, wherein a thickness of surface between adjacent
pockets is less than 50% of the maximum transverse dimension of the pockets.
33. ' The safety razor blade unit of claim 2, wherein there at least three longitudinally
extending rows of pockets.
34. The safety razor blade unit of claim 1 or 2, wherein the at least one elongate blade
comprises a linear edged blade member.
35. The safety razor blade unit of claim 1, wherein each opening is defined by side wall
portions depending inward from the skin contacting surface.
36. The safety razor blade unit of claim 2, wherein each pocket is defined by side wall
portions depending inward from the skin contacting surface.
37. The safety razor blade unit of claim 35, wherein the openings are further defined
by floor portions formed transverse to the depending side wall portions.
38. The safety razor blade unit of claim 36, wherein the pockets are further defined by
floor portions formed transverse to the depending side wall portions.
39. The safety razor blade unit of claim 1 or 20, wherein adjacent openings of the array
of openings are spaced at a distance of 5% to 100% of the maximum transverse dimension
of the openings.
40. safety razor blade unit of claim 2 or 22, wherein adjacent pockets of the array of
pockets are spaced at a distance of 5% to 100% of the maximum transverse dimension
of the pockets.
41. The safety razor blade unit of claim 28, further comprising a skin engaging member
occupying a position of a cap surface behind the at least one blade.
42. The safety razor blade unit of claim 20, wherein neighboring rows are offset relative
one another in the longitudinal direction by an amount less than a maximum transverse
dimension of the openings, whereby an overlap, as viewed projected in a direction
transverse to the longitudinal extent of the rows, results between neighboring openings
of adjacent rows.
43. The safety razor blade unit of claim 22, wherein neighboring rows are offset relative
one another in the longitudinal direction by an amount less than a maximum transverse
dimension of the pockets, whereby an overlap, as viewed projected in a direction transverse
to the longitudinal extent of the rows, results between neighboring pockets of adjacent
rows.
44. The safety razor blade unit of claim 37, wherein the opening floor portions define
discharge restricting apertures in communication with the common source, said discharge
restricting apertures metering a discharge of the product from the common source to
the skin contacting surface and constricting a back discharge into the common source
so the openings remain charged with product.
45. The safety razor blade unit of claim 38, wherein the pocket floor portions define
discharge restricting apertures in communication with the common source, said discharge
restricting apertures metering a discharge of the product from the common source to
the skin contacting surface and constricting a back discharge into the common source
so the pockets remain charged with product.