Safety razor and blade unit for safety razor
The present disclosure describes a blade unit ( 10 ) for a safety razor ( 8 ). The blade unit comprises a blade housing ( 12 ), a plurality of blades ( 18 ) disposed within the blade housing ( 12 ) to expose respective cutting edges ( 20 ) suitable for shaving, and a blade carrier supporting the plurality of blades ( 18 ). The blade housing ( 12 ) has a base on which the blade carrier is supported. The plurality of blades ( 18 ) and the blade carrier being displaceable downwards towards the base of the blade housing ( 12 ) during shaving, wherein an amount of downward displacement of the plurality of blades ( 18 ) and the blade carrier is limited by one or more protrusions extending upwards from the base of the blade housing ( 12 ).
1. A blade unit for a safety razor, wherein the blade unit comprises:
a blade housing;
a plurality of blades disposed within the blade housing to expose respective cutting edges suitable for shaving; and
a blade carrier which supports the plurality of blades and comprises a rack on which the plurality of blades is mounted and flexible legs that allow a downward displacement of the plurality of blades and the rack;
the blade housing having a base on which the blade carrier is supported;
the plurality of blades and the blade carrier being displaceable downwards towards the base of the blade housing during shaving, an amount of downward displacement of the plurality of blades and the blade carrier being limited by one or more protrusions which extend upwards from the base of the blade housing, and the flexible legs comprising pairs of flexible legs, the legs of each pair being connected together by a connecting member, at least one of the one or more protrusions being a connecting member-engaging protrusion extending along a length of the connecting member.
2. The blade unit of claim 1 , wherein the one or more protrusions limit the amount of displacement of the plurality of blades and the blade carrier to about halfway between a non-displaced position of the plurality of blades and the blade carrier and the base of the blade housing.
3. The blade unit of claim 1 , wherein a maximum downward displacement of the plurality of blades and the blade carrier is from about 0.75 mm to about 0.25 mm.
4. The blade unit of claim 1 , wherein a maximum downward displacement of the plurality of blades and the blade carrier is about 0.5 mm.
5. The blade unit of claim 1 , wherein with a force of up to 500 gf, the change in exposure of the cutting edges caused by the displacement is not more than 0.4 mm.
6. The blade unit of claim 1 , wherein the one or more protrusions limit the downward displacement in that the blade carrier comes into contact with the one or more protrusions only when the blade carrier displaces towards the base during shaving.
7. The blade unit of claim 1 , wherein at least another one of the one or more protrusions is a rack-engaging protrusion arranged to engage the rack to limit downward displacement of the plurality of blades and the blade carrier.
8. The blade unit of claim 7 , wherein rack-engaging protrusions are provided at each end of the blades.
9. The blade unit of claim 7 , wherein heights of the at least one connecting-member engaging protrusion and the at least one rack-engaging protrusion are such that these protrusions engage the at least one connecting member and the rack at the same time.
10. The blade unit of claim 1 , wherein a plurality of connecting member-engaging protrusions is arranged on the base to engage along a length of the connecting member.
11. The blade unit of claim 1 , wherein the flexible legs have feet, at least one of the feet being in contact with a metal plate disposed on the base of the blade housing.
12. The blade unit of claim 11 , wherein the at least one of the feet is in slidable contact with the metal plate.
13. The blade unit of claim 12 , wherein there are two pairs of flexible legs, one forward of the plurality of blades and one to a rear of the plurality of blades and wherein the feet of only one pair of flexible legs are in contact with the metal plate.
14. The blade unit of claim 12 , wherein the feet of the other pair of flexible legs are in contact with pads disposed on the base of the blade housing.
15. The blade unit of claim 1 , wherein there are two pairs of flexible legs, one forward of the plurality of blades and one to a rear of the plurality of blades, a respective plurality of connecting member-engaging protrusions being arranged on the base to engage along lengths of each of the connecting members.
16. The blade unit of claim 12 , wherein the blades are in electrical contact with the metal plate via the foot of at least one of the legs, so as to form a galvanic cathodic protection system in which the metal plate functions as a sacrificial anode that corrodes and the plurality of blades function as a cathode that is protected from corrosion.
17. A safety razor comprising the blade unit of claim 1 .