Cutlery – Razors – Multiple blade
Reexamination Certificate
2000-02-29
2001-10-23
Payer, Hwei-Siu (Department: 3724)
Cutlery
Razors
Multiple blade
C030S047000
Reexamination Certificate
active
06305084
ABSTRACT:
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to razors and, in particular, it concerns a razor cartridge employing narrow blades, and a method for assembling such cartridges.
Modern razor cartridges typically employ one of two techniques for retaining blades in position within the cartridge. The first employs a plurality of pins projecting from one of the cartridge elements which engage locating holes formed through each blade. An example of such a structure is U.S. Pat. No. 4,860,449 to Duncan.
The presence of locating holes within the blades required a certain minimum width of blade to ensure the structural integrity of the blades. Thus, blades of this type are typically at least about 5.5 mm wide. Since the total width of the cartridge is typically of the order of 10 mm, the use of two 5.5 mm blades requires that the blades are set in overlapping relation with a spacer element therebetween. This overlap greatly limits the area of drainage channels between the blades for flushing out hair and dirt, thereby leading to clogging of the cartridge.
In an attempt to reduce overlap between the blades, The Gillette Company® has developed a second blade retention technique which employs brazing of narrow blades onto a bent-over metal support element. An example of the resulting structure may be found in U.S. Pat. No. 5,056,222 to Miller et al.
The Gillette approach avoids the need for forming holes in the blades, thereby allowing a reduction in width of the blades to eliminate overlap and provide better drainage channels. This, however, is achieved at considerable cost. Specifically, the production techniques during which the blades are brazed onto the support elements are complex and expensive, leading to increased cost of the cartridge as a whole.
There is therefore a need for a razor cartridge which would employ narrow blades of no more than about 4 mm width without requiring either holes formed through the blades or brazing of the blades to support elements. It would also be highly advantageous to provide a method for assembling such a razor cartridge.
SUMMARY OF THE INVENTION
The present invention is a razor cartridge employing narrow blades, and a method for assembling such a cartridge.
According to the teachings of the present invention there is provided, a razor cartridge comprising: (a) a plurality of substantially planar blades, each of the blades having a cutting edge extending along substantially all of a major dimension termed length, each of the blades having an uninterrupted upper surface, a lower surface, and a width measured across the upper surface perpendicular to the length of no more than about 4 mm; (b) a base having at least one series of spaced-apart ribs configured to provide abutment features for abutting the lower surface of each of the blades so as to define at least partially a predetermined mounting position of each of the blades; and (c) a cover configured for engaging the base to form a unitary cartridge structure, the cover providing at least one abutment surface for each of the blades, the at least one abutment surface being configured to abut the upper surface of a corresponding one of the blades, thereby pressing the blade against the corresponding series of abutment features so as to retain the blade in the predetermined mounting position.
According to a further feature of the present invention, each of the spaced-apart ribs provides at least two projecting abutment features, the projecting abutment features defining localized regions of abutment with the lower surface.
According to a further feature of the present invention, the plurality of blades is implemented as three blades.
According to a further feature of the present invention, the spaced-apart ribs define a mounting position for each of the blades such that the blades are non-overlapping.
According to a further feature of the present invention, the spaced-apart ribs define mounting positions for the blades in which the upper surfaces are non-parallel.
According to a further feature of the present invention, there are also provided a plurality of projecting locating elements integrally formed with, and projecting from, one of the base and the cover so as to define a plurality of blade-receiving receptacles, each of the blade-receiving receptacles being configured to have a width slightly less than a width of each of the blades.
There is also provided according to the teachings of the present invention, a method for assembling a razor cartridge of a type having a plurality of narrow blades retained between two cartridge components which provide opposing sets of blade abutment features, the method comprising: (a) temporarily inserting a plurality of locating elements through a plurality of apertures formed through a first of the cartridge components so as to define a plurality of blade-receiving receptacles; (b) inserting a blade into each of the blade-receiving receptacles; (c) attaching the second of the cartridge components to the first cartridge component so as to form a razor cartridge with the blades retained between the two cartridge components; and (d) withdrawing the locating elements from the first cartridge component.
According to a further feature of the present invention, the withdrawing is performed substantially simultaneously with the attaching.
According to a further feature of the present invention, the locating elements are spring-mounted so as to be retractable, at least part of the withdrawing being achieved as a direct result of contact between the locating elements and the second cartridge element during the attaching.
According to a further feature of the present invention, each of the blade-receiving receptacles is configured to have a width slightly less than a width of each of the blades such that the inserting of the blades results in the blades being temporarily wedged within the blade-receiving receptacles.
There is also provided according to the teachings of the present invention, a method for assembling a razor cartridge of a type having a plurality of narrow blades retained between two cartridge components which provide opposing sets of blade abutment features, the method comprising: (a) providing a plurality of projecting locating elements projecting from a first of the cartridge components so as to define a plurality of blade-receiving receptacles, each of the blade-receiving receptacles being configured to have a width slightly less than a width of each of the blades; (b) inserting a blade into each of the blade-receiving receptacles so that it becomes wedged between adjacent ones of the locating elements; and (c) attaching the second of the cartridge components to the first cartridge component so as to form a razor cartridge with the blades retained between the two cartridge components, the second cartridge component being formed with a plurality of recesses for receiving the projecting locating elements.
REFERENCES:
patent: 4389773 (1983-06-01), Nissen et al.
patent: 4443940 (1984-04-01), Francis et al.
patent: 4985995 (1991-01-01), Coffin
patent: 5056222 (1991-10-01), Miller et al.
patent: 5063667 (1991-11-01), Jacobson
patent: 5388332 (1995-02-01), Oldroyd
patent: 5402574 (1995-04-01), Milner
patent: 5781997 (1998-07-01), Ferraro et al.
patent: 5822862 (1998-10-01), Ferraro
Friedman Mark M.
Payer Hwei-Siu
Wheel Technology Ltd.
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