GB1593979A

GB1593979A - Safety razor

Info

Publication number: GB1593979A
Application number: GB4722477A
Authority: GB
Original assignee: Gillette Co LLC
Current assignee: Gillette Co LLC
Priority date: 1978-05-30
Filing date: 1978-05-30
Publication date: 1981-07-22

Description

(54) SAFETY RAZOR (71) We, THE GILLETTE COM PANY, a Company organised and existing under the laws of the State of Delaware, United States of America of Prudential Tower Building, Boston, Massachusetts 02199, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to safety razor shaving heads of the form in which at least one blade is permanently secured to a blade support of moulded plastics material, to form a shaving head, or a complete razor, which is discarded as a whole when the cutting edge of the or each blade becomes dulled.

The shaving head may be of the disposable cartridge type adapted for coupling to and uncoupling from a razor handlc, or may be integral with the handle so that the complete razor is disposable and discarded as a unit when the cutting edges of the blades are dulled.

Shaving units of the cartridge type have gained considerable popularity in recent years and invariably comprise a number of moulded plastics parts which are secured together to clamp the blade or blades in position.

The present invention provides a shaving head which is particularly simple and convenient to manufacture and which obviates the need to pre-form and assemble the moulded plastics components mentioned above.

In accordance with the invention, there is provided a shaving head comprising a blade support of moulded plastics material and at least one blade member sharpened along one longitudinal edge, the blade member being pushed into a slot in the blade support and permanently secured therein by positive mechanical interengagement between the blade member and the support, with its sharpened edge projecting forwardly from the support.

The invention is of particular, but not exclusive, advantage in its application to razors having two (or more) blade members whose cutting edges are arranged to act in tandem upon the skin of the user, the invention having the particular advantage of permitting manufacturing and assembly costs to be kept very low.

In one embodiment of the invention, the support is formed of a foamed plastics material which, as moulded, has no slots or other apertures formed for pre-location of the blade or blades, which are simply forced into the plastics material so as to form their own slots.

In another embodiment, the support is of deformable plastics material formed with a slot to receive the or each blade member, the latter having a hole or holes through it and the blade is secured in the slot by punching or "coining" the plastics material locally to upset material into the hole or holes.

In other embodiments, the or each blade is pushed into a planar gap defined by two opposed rows of spaced projections integral with the support, which bear against the inserted blade from above and below, each projection being positioned opposite a gap between adjacent projections in the opposite row. This arrangement permits accurate sizing of the gap and also has the advantage of weight saving compared with a simple slit being formed in the support.

Some forms of razor in accordance with the invention will now be described, by way of example, with reference to the drawings accompanying the Provisional Specification, in which: Figure 1 is an exploded perspective view of one form of razor; Figure 2 is a cross-section on the line 'A-A' of Figure 1; Figures 3 and 4 are scrap cross-sections of a second form of razor; Figure 5 is a scrap perspective view of the tandem blades employed in the razor of Figures 3 and 4; Figure 6 is an exploded perspective view of a third form of razor; Figure 7 is a scrap view on arrow 'B' of Figure 6; Figure 8 is a scrap perspective view showing a detail; Figure 9 is an enlarged cross-section showing a modification to the razor of Figure 6; Figure 10 is an exploded perspective view of another form of razor; and Figure 11 is an enlarged scrap view on arrow 'C' of Figure 10.

In each of the illustrated embodiments herein, the razor comprises a moulded plastics support in the form of a head 1 integral with a handle 2 and having skin engaging cap and guard portions 3, 4.

Tandem blades 6 and 7 are set in the head 1, having their parallel cutting edges exposed between the cap and guard portions and arranged to act in tandem upon the skin of the user. It will be readily appreciated by those skilled in the art that the heads 1 could in each case alternatively be detachably mounted on the handle 2.

The razor illustrated in Figures 1 and 2 has its head 1 moulded from a closed cell foamed plastics material, such as polystyrene, in which the voids amount to about 60% of the total volume of the moulding.

The head is formed without any pre-formed slots or the like for reception of the blades but has two steps 8 and 9 for vertical location of the blades, i.e. in a direction perpendicular to the plane of the blades.

The blades are formed at their rear edges with rearwardly directed prongs 11.

Additionally, forwardly directed barbs 12 are struck up out of the upper surface of the trailing blade 7 and out of the lower surface of the leading blade 6. The blades are assembled and secured in the head by pushing them into the plastics foam, so that the prongs 11 pierce the foam, and in the final stage of movement of each blade into the head, the barbs 12 are engaged in the foam to resist detachment of the blades. The blades could be inserted individually, but are preferably inserted simultaneously.

It is not essential to provide the steps 8 and 9 for vertical location. The blades could, for example, be located relative to each other in a gripping tool for simultaneous insertion, and the tool itself located with reference to a suitable datum surface of the head 1 to determine the precise position of the blade pair.

Figures 3, 4 and 5 illustrate a razor in which a solid moulded plastics head 1 is moulded with slots 13 to receive the blades 6, 7. Each blade has, say, four holes, of which two holes 14 are of larger diameter than the other two holes 16 in each blade, and the larger holes 14 of each blade are aligned with smaller holes 16 of the other when the blades are positioned in their slots.

The head is formed with two holes to receive lower coining punches 17, these holes being aligned with the larger holes 14 of the leading blade 6 and extending upwardly to the level of the slot which receives the trailing blade 7.

Correspondingly, two holes for upper coining punches 18 extend downwardly through the head to the level of the slot which receives the leading blade 6.

Additionally, blind bores are aligned with the latter holes to receive punches 19.

In assembly, the blades are inserted in their slots with slight frictional restraint and the coining punches 17 and 18 are advanced to their illustrated positions. The punches 19 and a corresponding pair of punches 21 are then operated to upset the plastics material into the smaller holes 16 and thus secure the blades. The punches are then withdrawn and the finished assembly removed from the punch fixture.

In the razor shown in Figures 6 to 8 the head is moulded to have a comb-form spacer constituted by a series of forwardly projecting fingers 24 disposed between the cap portion 3 and an underlying blade platform portion 26. The lower surface of the cap portion 3 and the upper surface of the blade platform portion both consist of a series of spaced parallel projections 3A and 26A, the projections above and below the spacer fingers 24 being in line with each other and vertically opposite a gap between adjacent spacer fingers 24. There is thus defined a planar gap 27 between the spacer and the cap to receive the trailing blade 7, and another planar gap 28 between the spacer and the blade platform portion 26 to receive the leading blade 6. Each gap has a depth of say 0.1 mm to suit the thickness of the blades.

The formation of the two narrow gaps by offset staggered projection is more readily achieved in an injection moulding process than is the formation of gaps having continuous upper and lower walls, for which a very thin insert is required in the mould, and there is also a weight saving benefit which reduces the cost of material per unit.

To provide for positive retention of the blades, the blades are formed at their end edges with rectangular notches 30 and the head is formed with ramp projections 31 to provide snap-fitting engagement in the notches when the blades are pushed home.

In a possible modification of this technique, illustrated in Figure 9, the blades have forwardly directed resilient barbs 32 struckup out of them, which bite into the plastics material of the head 1 to resist withdrawal of the inserted blades.

A further detailed modification is illustrated in the ringed portion of Figure 6, which shows the gaps between the cap projections 3A carried through to the upper skin engaging surface of the cap 3.

The spaces between the various blade engaging projections may be connected to soap drainage holes (not shown) extending upwardly from the underside of the head 1, to permit ready clearance from the blade edge regions of soap and shaving debris.

The razor shown in Figures 10 and 11 also employs the principle of forming narrow gaps to receive the blades by opposed sets of spaced and staggered projections. The projections depending from the cap 3 are of T-section each having a broad base 41 and a narrow web 42 whose downwardly facing horizontal surfaces are disposed in respective planes 41' and 42'.

Correspondingly, the projections upstanding from the blade platform portion are of inverted T-section, with broad bases 43 and narrow webs 44 having upwardly facing horizontal surfaces disposed in respective planes 43' and 44'. The spacing between the adjacent planes 41', 44' and 42', 43' is 0.1 mm.

The blades 6 and 7 are formed with respective series of slots 46, 47 extending forwardly from the rear edges of the blades.

The slots 46 in the leading blade are aligned with the webs 44 and the slots 47 of the trailing blade and aligned with the webs 42.

Thus, in the assembled razor, each blade is located longitudinally by the webs over which its slots engage.

The trailing blade 7 is supported at its upper surface against the base portion 41 in plane 41' and at its lower surface against the webs 44 in plane 44'. Similarly, the leading blade 6 is supported by the projection surfaces in planes 42' and 43'. The blades are positively secured in the head, for example, by any of the techniques described above.

In this construction the narrow gaps necessary for vertical blade location and spacing are formed by a particularly sturdy core-tool, and again it is possible to provide soap holes in the head to cater for good clearance of soap and shaving debris from the gaps between projections.

It would be possible in the embodiment of Figures 6 to 9 and Figures 10 and 11 to provide for positive blade retention by use of the coining method illustrated in Figures 3 to 5.

In each of the above described embodiments, the head and handle are moulded as an integral unit to form a complete, disposable razor. It will, however, be clear to those skilled in the art that the shaving head could be formed for detachable coupling with a separate handle if desired.

WHAT WE CLAIM IS: 1. A shaving head comprising a blade support of moulded plastics material and at least one blade member sharpened along one longitudinal edge, the blade member being pushed into a slot in the blade support and permanently secured therein by positive mechanical interengagement between the blade member and the support, with its sharpened edge projecting forwardly from the support.

2. A shaving head comprising a blade support of moulded foamed plastics material, and at least one blade member sharpened along one longitudinal edge, the blade member being pushed into the blade support so as to form its own slot in the support, and permanently secured therein by positive mechanical interengagement between forwardly directed barbs integral with the blade member and the material of the support, with the sharpened edge projecting forwardly from the support.

3. A shaving head according to claim 2, wherein the blade member is formed, at its edge remote from the sharpened edge, with a plurality of rearwardly directed prongs.

4. A shaving head comprising a blade support of moulded plastics material having a moulded slot in which is located a blade member sharpened along one longitudinal edge which projects forwardly out of the slot, the blade member having one or more apertures through into which the material of the support is locally upset to provide permanent positive mechanical retention of the blade in its slot.

5. A shaving head according to claim 4, wherein the support is formed with a parallel pair of slots in which are located two respective blade members whose sharpened edges are arranged to act in tandem upon the skin of the user, and wherein each said aperture in each blade is aligned with a larger hole in the other blade to permit passage through the larger hole of a coining punch employed in manufacture of the unit in upsetting of the support material.

6. A shaving head comprising a blade support of moulded plastics material formed with a slot into which is inserted a blade member sharpened along one longitudinal edge, which projects forwardly from the slot, the blade member being permanently retained in the slot by positive mechanical interengagement between the blade member and the support, and wherein the slot is defined by two opposed rows of projections which bear against the blade member from above and below, each projection being positioned opposite a space between adjacent projections in the opposite row.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. which shows the gaps between the cap projections 3A carried through to the upper skin engaging surface of the cap 3. The spaces between the various blade engaging projections may be connected to soap drainage holes (not shown) extending upwardly from the underside of the head 1, to permit ready clearance from the blade edge regions of soap and shaving debris. The razor shown in Figures 10 and 11 also employs the principle of forming narrow gaps to receive the blades by opposed sets of spaced and staggered projections. The projections depending from the cap 3 are of T-section each having a broad base 41 and a narrow web 42 whose downwardly facing horizontal surfaces are disposed in respective planes 41' and 42'. Correspondingly, the projections upstanding from the blade platform portion are of inverted T-section, with broad bases 43 and narrow webs 44 having upwardly facing horizontal surfaces disposed in respective planes 43' and 44'. The spacing between the adjacent planes 41', 44' and 42', 43' is 0.1 mm. The blades 6 and 7 are formed with respective series of slots 46, 47 extending forwardly from the rear edges of the blades. The slots 46 in the leading blade are aligned with the webs 44 and the slots 47 of the trailing blade and aligned with the webs 42. Thus, in the assembled razor, each blade is located longitudinally by the webs over which its slots engage. The trailing blade 7 is supported at its upper surface against the base portion 41 in plane 41' and at its lower surface against the webs 44 in plane 44'. Similarly, the leading blade 6 is supported by the projection surfaces in planes 42' and 43'. The blades are positively secured in the head, for example, by any of the techniques described above. In this construction the narrow gaps necessary for vertical blade location and spacing are formed by a particularly sturdy core-tool, and again it is possible to provide soap holes in the head to cater for good clearance of soap and shaving debris from the gaps between projections. It would be possible in the embodiment of Figures 6 to 9 and Figures 10 and 11 to provide for positive blade retention by use of the coining method illustrated in Figures 3 to 5. In each of the above described embodiments, the head and handle are moulded as an integral unit to form a complete, disposable razor. It will, however, be clear to those skilled in the art that the shaving head could be formed for detachable coupling with a separate handle if desired. WHAT WE CLAIM IS:

1. A shaving head comprising a blade support of moulded plastics material and at least one blade member sharpened along one longitudinal edge, the blade member being pushed into a slot in the blade support and permanently secured therein by positive mechanical interengagement between the blade member and the support, with its sharpened edge projecting forwardly from the support.

7.. A shaving head according to claim 6, in

which two said slots are provided parallel with each other to receive two respective blade members, the sharpened edges of which are positioned to act in tandem upon the skin of the user, the two slots being formed by two rows of projections above and below the blade members and an intermediate row of projections formed as forwardly projecting fingers whose thickness sets the spacing between the pair of blade members.

8. A shaving head according to claim 6, including a pair of parallel blade members having their sharpened edges positioned to act in tandem upon the skin of the user, the support being formed with a set of downwardly extending upper projections which extend through slots in the upper blade member to bear against the upper surface of the lower blade member, and a set of upwardly extending projections which extend through slots to the lower blade member to bear against the lower surface of the upper blade member, the projections of each set having base portions forming location surfaces which co-operate with the projections of the other set to define the slots in which the blade members are inserted.

9. A shaving head according to any one of claims 6 to 8, wherein the blade member or each blade member is formed with forwardly directed barbs which make snapfitting engagement with recesses formed in the support, or bite into the material of the support, upon insertion of the blades into the support.

10. A shaving head according to any one of claims 6 to 8, wherein the blade member or each blade member is formed with apertures into which the material of the support is upset to provide positive retention of the blade in the support.

11. A shaving head according to any preceding claim, wherein the support is shaped to provide skin engaging cap and guard surfaces.

12. A shaving head according to any preceding claim wherein the support is permanently united with a handle to constitute a complete, disposable razor.

13. A shaving head or safety razor substantially as herein described with reference to Figures 1 and 2 of the drawings accompanying the Provisional Specification.

14. A shaving head or safety razor substantially as herein described with reference to Figures 3, 4 and 5 of the drawings accompanying the Provisional Specification.

15. A shaving head or safety razor substantially as herein described with reference to Figures 6 and 7 or Figures 6 and 7 as modified by Figure 8 or Figure 9 of the drawings .accompanying the Provisional Specification.

16. A shaving head or safety razor substantially as herein described with reference to Figures 10 and 11 of the drawings accompanying the Provisional Specification.