[0001] This invention is concerned with the honing of edge cutting tools, and in particular,
with the blades of safety razors, with the emphasis being placed upon twin-bladed
razors.
[0002] When early safety razors made use of flexible, twin-edged blades, it was a relatively
common practice to hone the blades by running them around the inside of a tumbler
of water. This operation is however, not effective with the modern twin-bladed razor,
with its cutting formations embedded in a rigid matrix.
[0003] With the advent of the twin-bladed razor, it has become common practice for the blades
to be thrown away as soon as they become slightly blunt and even more recently, the
totally disposable razor has been made available on the market.
[0004] It was found that detritus tends to accumulate and eventually clog the space between
the blades and this contributes to the rapid degradation of the blade and generally
to an unhygienic state of affairs. The blade manufacturers have resorted to various
mechanical arrangements intended to aleviate the latter mentioned problem but these
have proved only partially effective.
[0005] The present invention aims principally to provide a means of enhancing the life of
such blades and at the same time, brings a welcome improvement in blade hygiene.
[0006] Therefore, according to the invention, there is provided a base plate including means
adapted to engage a safety razor with blade in place; a shroud into which the head
of the mounted razor extends, and means to inject a stream of water into the shroud
to flow along the head of the razor in the plane of the blade(s).
[0007] Further according to the invention, a header chamber receives the water and there
is an opening or openings in a common wall between the shroud and the chamber for
passage of the water to the blade(s) of the mounted razor.
[0008] In order to facilitate further understanding of the invention, one preferred embodiment
will now be described in detail with reference to the accompanying drawing which is
a side elevation, partly sectioned. In the drawing, the device consists of a base
plate 10 on which there is a clip 12 for mounting a safety razor 14; a shroud 15 into
which the head 16 of the razor 14 extends; a header chamber 18; a common wall 20 between
the chamber 18 and the shroud 15; and an opening 22 in the wall 20 which is in the
form of a slot running parallel to the plane of the blades 30. A flange 24 is provided
to create a stop to locate the razor 14 properly.
[0009] A rubber cushion 26 is attached to the header chamber 18. It has a central hole 28
that is in alignment with a hole in the header chamber 18. In use, the rubber pad
26 is pressed firmly against a water tap (not shown). Water from the tap flows through
the hole 28, into the header chamber 18 and thence through the opening 22. Water emerging
from the opening 22 impinges on the blades 30 of the razor in a concentrated stream
and flows across the blades to exercise a honing action which tends to maintain their
acuity. In addition, the passage of water through the shroud 15 will tend to force
out detritus which may have accumulated in the space between the blades 30.
[0010] The principle of operation of the device is essentially similar to that which will
enable the constant dripping of water to wear away a stone.
[0011] In shaving, the blades are always drawn across the skin in a uniform direction and
this tends to cause the very keen edge of the blades to be slowly bent back until
the cutting angle of the blades has been so altered that the blade now feels blunt.
[0012] By passing a stream of water over the blades in the opposite direction, and particularly
when under reasonable pressure, the very keen edge is gently bent back to the correct
angle and repeated use of the apparatus of the invention will keep this cutting edge
properly aligned and honed for a considerable period of time. Tests thus far conducted
indicate that the average blade life can be extended to between 18 and 24 months which
contrasts favourably with the present 1 to 2 months life expectancy of such blades.
1. A device for honing razor blades comprising a base plate; means on the base plate
to engage a safety razor; a shroud into which the head of the razor extends; and means
to inject a stream of water into the shroud to flow along the head of the mounted
razor across the blade(s).
2. A device for honing razor blades as claimed in claim 1 including a header chamber
to receive the water; a wall common to the chamber and the shroud; and an opening
or openings in the wall for passage of water from the chamber into the shroud.
3. A device for honing razor blades as claimed in claim 2 in which the opening takes
the form of a slot or a line of holes.
4. A device for honing razor blades as claimed in any of the claims 1 to 3, including
a resilient cushion apertured so as to direct water from a tap into the shroud.
5. A device for honing razor blades as claimed in claim 4 and in so far as it depends
upon claim 2, in which the cushion is attached to the outside of the header chamber,
and the cushion and the chamber have registering holes for passage of water from the
tap into the chamber.