CA2117771C

CA2117771C - Razor with a movable cartridge

Info

Publication number: CA2117771C
Application number: CA002117771A
Authority: CA
Inventors: Brian Oldroyd
Original assignee: Gillette Co LLC
Current assignee: Gillette Co LLC
Priority date: 1992-04-13
Filing date: 1993-04-12
Publication date: 1999-03-23
Anticipated expiration: 2013-04-12
Also published as: CA2117771A1; US20020104223A1; EP0638015B1; US6381857B1; EP0638015A1; EP0638015A4; US6115924A; ES2129519T3; WO1993020983A1; JP3388583B2; GB9208098D0; JPH07505799A; DE69323305D1; DE69323305T2

Abstract

A razor includes a handle and a cartridge (11) pivotally mounted thereon by a cartridge carrier (15). A four-bar linkage comprising links (16) and a pair of bell cranks (17A, 17B) mounts the cartridge carrier (15) to the handle so that a centre of rotation of the cartridge is on or below a surface (42) to be shaved.

Description

2 ~ ~ 77~
W O 93/20983 P(~r/US93/03439 RAZOR WITH A MOVABLE CARTRIDGE
This invent~on relate~ to a cartridge razor which includes a handle and a cartridge carrier mounted to the handle in a way which allow~ the cartridge to rotate relative to the handle about an axis which i8 perpendicular to the edge of the or each blade of the cartridge and parallel to the surface to be shaved, thereby to accommodate changing contours of a surface to be shaved.
Twin-blade cartridges which ~wivel about an axis parallel to the blade edges are well-known. Such 8wivell~ng improves contact between the blades and the surface being shaved, and it ha~ been found that the 8wivel1~ng about the orthogonal axis improves blade contact, end to end. See GB-A-2116470 and GB-A-2172236.
Although the razor of GB-A-2116470 provides im~ Oved conformance with facial contour~, end to end of the shaving cartridge, there iB scope f~r further improvement and it is one object of th~ pre~ent invention to achieve ~ such an implo~ ~cnt. What is required is a way of mounting the cartridge to the handle which allow~ the cartridge to ~ ve 8~ othly and with a minimum of friction about the axi~ perpendicular to the blade edge or edges, whenever there i~ a -W093/20983 ~ ~ ~ 7 7 7 ~ ~ PCT/US93/03~39 change of the angle between the handle and the surface being ~haved. Further, the mounting ~hould be compact enough not to interfere unduly with the user~s vision of the area being shaved, or with subsequent rinsing of the cartridge.
A cartridge razor of the type initially defined above, and in accordance with the present invention, is characterized in that the rotation perpendicular to the edge of the or each blade of the cartridge is about an axis of rotation which lies either on or below the said surface to be shaved.
8y ~o locating the rotation centre, it i8 possible to establish a stable reaction to changing contours of the surface being shaved, which ensures that the end to end rocking movements of the cartridge do not involve any motion in the line of the blade edges relative to that surface.
Conventional swi~elling movement parallel to the edge of the or each blade of the cartridge can be pro~ided between a cartridge carrier and the cartridge. Preferably, the axis of rotation of the cartridge parallel to the blade edge(s) is also on or below the surface to be shaved. When the two orthogonal rotational axes intersect, the combination of the two swivel axes creates an effective univer~al joint on or below the surface being sha~ed.
The cartridge carrier can itself be carried on a four-bar linkage which lies in a plane parallel to the blade edges. A suitable four-bar linkage has first and second transverse - link~, each with a mid-point pivotally mounted to the handle, and two opposite ends each pi~otally mounted to an extension link, itself mounted pivotally to the end of the cartridge f3~ 1777~

W093/20983 PCT/US93/0~39 carrier, 80 that each end of the carrier is supported by one of the extension links of the four-bar linkages.
Conveniently, each of the four-bar transverse links is a bell crank having an apex at its mid-point and cran~e~ left hand and right hand limbs ext~n~;ng in opposite directions from the apex but 8Ubt~nA; ng an angle of le88 than 180~, for example, 60~, BO that the bell crank points, like an arrow head, towards the cartridge carrier. This is one effective way to move the centre of rotation of the carrier away from its mounting in the handle and towards the desired position on or behind the surface to be shavQd.
A four-bar lin~age as described immediately above has already been disclosed, see GB 1460732, but only as a pair of such l~n~os, to provide swivel motion about the axis parallel to the blade edges. The rotational axis is above the surface to be shaved.
Preferably, a biasing spring is provided, to urge the carrier to a start disposition 80 that during shaving whenever the cartridge is no longer subject to forces ten~;ng to rotate it about the rotat;oral axis ~e ~_~dicular to the blade edges, the biasing means will urge the carrier back to its start disposition. A preferred biasing spring is a resilient wishbone mounted at its apex to the said bell crank and with its l;mhs pressing against the two extension links.
For a better understan~;ng of the in~ention, and to show more clearly how the same may be carried into effect, reference will now be made, by way of example, to the accompanying W093/20983 fi f ' ~7 7 7 ~ PCT/US93/0~39 drawings, in which:
Figure 1 is a first elevation, exploded, to show various individual components of a preferred embodiment of razor in accordance with the invention;
Figure 2A is an exploded side ~iew of a portion of the l;n~age as seen along viow line 2A - 2A of Figure 1;
Figure 2B ie a longit~;nal cross sectional view as taken along line 2B - 2B of Figure 1, the parts being shown in their assembled position;
Figure 3 is a front ele~ational ~iew of the assembled razor with the cover plates removed;
Figure 4 is a front elevat; ~n~l ~iew s;m;lar to Figure 3 with the razor shown in a tilted position;
Figure 5 is a fragmentary ele~ational view showing the cartridge being reta;n-~ by the carrier; a~d, Figure 6 is a ~iew similar to Figure 5 showing the cartridge released from the carrier.
Referring to Figure 1, a sha~ing cartridge 11 is held by a pair of shell bearings 12, in a manner known per se, to the remainder of the razor system. A plunger 13 is mounted in the razor for endwise mo~ement and a compression spring 14 acts on the plunger to urge it into endwise pressure on a ramp surface 9 on the cartridge, thereby to urge the cartridge into a centered median disposition in the shell bearings 12, as is known per se. To change the cartridge the shell bearings are squeezed together. Not only doe~ this release the bearings but it also causes ramp surfaces 7, 8 to depress the plunger 13 against the action of 2~L~ 777 ~
W O 93/20983 PC~r/US93/03439 .._ the spring 14, to release the cartridge 11 from the razor. This also is known per se.
A cartridge carrier 15 carries the shell boarings 12 and plunger 13. The carrier is itself ~ unted on a four-bar linkago parallel with the blade odgos. The l~n~go comprises a pair of oxtension links 16~ one on oach side of each of a pair of bell cranks 17A, 17B. These cranks are themsel~es pivotally mounted to a pl~nar aroa 18 of the razor handle. A rosilient wi~hho~o spring 19 is clipped on to the upper bell crank 17A 80 that its two legs pross against the extension links 16 to centre the l;n~ge. A plate 20 co~ers the carrier 15 and has an arcuate edge 21 which abuts a corre4r~A; ng edge 22 on a cover plate 23 for the handlo aroa 18. The arcs of the odgos 21, 22 are centered on the centre of rotation of the cartridgo carrier 15 80 that, when the carrier 15 rocks to follow facial contours, thore i8 relati~e movement between the edges 21 and 22.
In tho preferred embodiment this rolati~e motion can be ~ ;ng mo~ement.
Roferring now to Figure 2A and 2B, the four-bar linkage is shown from the sido 80 that only ono of the extension links 16 is ~isible.
Each such link 16 has an upper boss 30 to ongage with the upper bell crank 17A and a lower boss 32 to ongage with the lower crank 17B. At the apex of the upper crank 17A is a boss 34 which i8 carried in a bore 3 r ~n the handle 18. At the apex of the lower crank 17B is a boss 36 which is carried in a bore 37.
Referring now to Figure 3, each extonsion link 16 is pivotally ronnected to the cartridge carrier 15 by a boss 40. The carrier 15 rocks about these two bosses 40 in a locus W093/20983 2 ~ 1 7 7 ~ 1 PCT/US93/0343g which corresponds to a centre of rotation 41 which is determined by the geometry of the bell cranks 17A and 17B. It can be seen that the centre of rotation 41 is on the opposite side of the shaving surface 42 of the cartridge from the razor handle, that is, below the surface to be shaved .
Referring now to Figure 4, a 15~ tilt about the centre of rotation 41 has the effect of pressing the left _and leg 43 of the wi~hhone 19 against the left hand link 16 and the resultant elastic deformation of the leg produces a force t~n~;ng to restore the four-bar l;n~age to a central disposition. The other leg 44 provides the restoring force when the rotation is in the other direction. With rotation as shown in Fig. 4, the leg 44 simply mo~es out of contact with its adjacent extension link 16.
Figures 5 and 6 show how the cartridge is mounted and separated from the remainder of the razor. As is ment;ons~ abo~e, the construction and operation is in itself already ~nown, as from the ~'co~ (trademark) razor, sold by the present Applicant.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE
DEFINED AS FOLLOWS:

1. A cartridge razor comprising a handle and a cartridge carrier mounted to the handle, said cartridge carrier supporting a cartridge mounting one or more cutting blades, each such blade having a cutting edge, said cartridge carrier and supported cartridge being pivotally movable, with changing contours of a surface to be shaved, about an axis which is perpendicular to each such blade cutting edge and parallel to a plane intersecting each such blade cutting edge, said plane being generally parallel to the surface being shaved, wherein said axis lies either on or below the surface to be shaved and said cartridge carrier is connected to said handle by a four-bar linkage which lies in a plane parallel to each such blade cutting edge, said four-bar linkage comprising first and second transverse links and a pair of generally parallel extension links, each of said transverse links having a mid-point pivot connection with said handle and opposite end pivot connections with said extension links, said mid-point connections being substantially parallel to said axis, one end of each said extension link being pivotally connected to a corresponding end of said cartridge carrier, whereby as pivotal motion of said transverse links occurs about said mid-point connections said extension links are in turn displaced relative to said axis to cause pivoting of said cartridge carrier and supported cartridge.

2. A cartridge razor as claimed in claim 1, wherein the transverse links are bell cranks.

3. A cartridge razor as claimed in claim 1, wherein the cartridge carrier is provided with a cover which moves with the cartridge carrier relative to the handle, the cover having an arcuate edge which abuts a corresponding edge portion of a surface of the handle, for relative sliding movement between the edge and said edge portion when the cartridge carrier moves relative to the handle.

4. A cartridge razor as claimed in claim 1, wherein biasing means is arranged to urge the cartridge carrier to pivot to a start disposition as soon as the cartridge carrier is no longer subject to any shaving forces tending to displace the cartridge carrier from said start disposition.

5. A razor comprising a handle and a cartridge carrier mounted to the handle, said cartridge carrier having shell bearings adapted to receive and support a cartridge in which is disposed at least one elongated blade having a cutting edge, said cartridge having shell bearing engaging surfaces formed on an underside thereof, said cartridge carrier supporting the cartridge on said shell bearings for rotation of said cartridge carrier and supported cartridge about a first axis parallel to the cutting edge of said at least one blade, and said cartridge carrier being supported on a four-bar linkage which provides for pivotal movement of said cartridge carrier and supported cartridge about a second axis which is perpendicular to the cutting edge of said at least one blade and parallel to a plane which intersects the cutting edge of said at least one blade, said plane being generally parallel to a surface to be shaved, to thereby permit said pivotal movement of the cartridge carrier and supported cartridge with changing contours of the surface to be shaved, said four-bar linkage lying in a plane parallel to said cutting edge of said at least one blade and having first and second transverse links pivotally connected at opposite ends thereof with one of first and second extension links, at least one of said transverse links being operatively connected to said handle about a third axis substantially parallel to said second axis, and said extension links supporting the cartridge carrier at one end thereof whereby upon pivotal displacement of said four-bar linkage about said third axis said extension links are in turn displaced relative to said second axis to cause said pivotal movement of said cartridge carrier and supported cartridge, and wherein the second axis is either on or below the surface to be shaved.

6. A razor as claimed in claim 5, wherein the second axis and the first axis intersect, forming an effective universal joint.

7. A wet razor comprising a handle and a carrier mounted to the handle, said carrier supporting a razor head having a longitudinal axis and one or more lengthwise extending blades, each such blade having a cutting edge, said carrier supporting the razor head to rock relative to the handle about a first axis which is perpendicular to the cutting edge of each such blade and parallel to a surface to be shaved, with changing contours of the surface to be shaved, and said carrier having pivot bearings for mounting said razor head for swiveling about a second axis parallel to the longitudinal axis, and wherein said first axis is located generally on or spaced outward from each such blade cutting edge along a direction extending from inside of the razor head outward towards the surface to be shaved, and wherein a four-bar linkage is disposed in the handle lying generally parallel to the longitudinal axis of the razor head, said four-bar linkage having a pair of spaced extension links lying longitudinally of the handle and transverse links lying transversely of the handle to provide a pivotal connection to said handle to permit said four-bar linkage to pivot at a mid-point of at least one such transverse link about a third axis, said extension links extending towards the razor head and supporting the carrier, whereby upon pivotal displacement of said four-bar linkage about said third axis one said extension link will advance in the direction of the razor head while the other extension link retracts to cause rocking displacement of said carrier and supported razor head about said first axis and whereby the second axis and the first axis are mutually transverse.

8. A wet razor according to claim 7, wherein a spring disposed in the handle biases the four-bar linkage to a start disposition.

9. A wet razor according to claim 7, wherein the razor head comprises a double razor blade assembly.

10. A wet razor according to claim 7, wherein the pivot bearings comprise shell bearings.

11. A wet razor according to claim 7, wherein the four-bar linkage includes bell cranks.

12. A wet razor according to claim 7, wherein the razor head is pivotable in either direction about the first axis about 15°.

13. A wet razor according to claim 7, wherein the handle has a housing defining a cavity at a forward region towards the carrier, said cavity having a generally planar area between opposed side walls arranged perpendicular to the planar area and extending towards the carrier, said planar area being disposed generally parallel to the first axis and perpendicular to the second axis, said four-bar linkage being disposed on the generally planar area, and the side walls constraining the extension links of the four-bar linkage in a pivoted condition.

14. A wet razor handle for supporting a shaving cartridge including one or more blades having cutting edges, said handle comprising an elongated hand engaging structure having an upper end, a housing structure at the upper end of said elongated hand engaging structure having a cavity therein, a cartridge connecting structure located above said housing structure that supports said cartridge and provides pivotal movement of said cartridge about a first axis that is parallel to the cutting edges of said one or more blades, a linkage that connects said cartridge connecting structure to said housing and provides pivotal movement of said cartridge connecting structure about a virtual second axis that is perpendicular to said first axis and is located above said housing structure to provide a rocking motion of said cartridge, said linkage comprising first and second extension links that are each connected to said cartridge connecting structure, said extension links having lower portions, mid-portions and upper portions, and at least one transverse link that is pivotally connected at its ends to said lower portions of said extension links and is pivotally connected at a midpoint of said transverse link to said hand engaging structure at a third pivot axis that is parallel to said second pivot axis, said transverse link and said lower portions and mid-portions of said extension links being located within said cavity in said housing structure, the upper portions of said extension links extending upward and out of said housing structure, said handle also including motion-limiting structure that maintains said mid-portions of said extension links in a predetermined sideways space relation so as to limit sideways travel of said extension links, whereby pivoting of said transverse link about said virtual second axis causes movement of one said extension link in an upward direction and simultaneous movement of the other said extension link in a downward direction so as to cause pivoting of said cartridge connecting structure with respect to said virtual second axis.

15. The handle of claim 14 wherein said third pivot axis is at a fixed location on said housing.

16. The handle of claim 14 wherein said motion-limiting structure comprises a second transverse link that is pivotally connected at its ends to said mid-portions of said extension links.

17. The handle of claim 14 further comprising a biasing spring tending to bias said transverse link to an orientation in which said upper portions of said extension links are at the same height with respect to said housing structure.

18. The handle of claim 14 wherein said extension links are straight.

19. The handle of claim 14 wherein said cartridge connecting structure is pivotally connected to said upper portions of said extension links and is separate from said extension links.

20. The handle of claim 14 wherein said cartridge connecting structure comprises shell bearings.

21. The handle of claim 14 wherein said virtual second axis is located on or below the surface to be shaved.

22. The handle of claim 14 wherein said ends of said transverse link are connected to said lower portions of said extension links to rotate about pivot axes that are at fixed locations with respect to said lower portions of said extension links.

23. The handle of claim 14 wherein said transverse link is a bell crank.