GB2246756A

GB2246756A - A can opener

Info

Publication number: GB2246756A
Application number: GB9017098A
Authority: GB
Inventors: Joseph Augustine Teren Pereira
Original assignee: William Levene Ltd
Current assignee: William Levene Ltd
Priority date: 1990-08-03
Filing date: 1990-08-03
Publication date: 1992-02-12
Anticipated expiration: 2010-08-03
Also published as: GB9017098D0; GB2246756B; HK140994A; GB9111720D0

Abstract

A can opener comprises a rotary cutting wheel 7 and a rotary traction wheel 12, the latter being shaped to distort the rim of the can while it is being cut by the cutting wheel whereby the overlapping engagement between the end wall of the can and the side wall of the can is loosened. The traction wheel 12 includes a first portion of a frusto-conical shape 17 which engages with the inside surface of the can rim, and a second portion (20, fig 5) arranged to contact the top surface of the rim. Two body portions 1 and 3 are arranged for relative pivotal movement, one portion carrying the traction wheel has a elongate handle portion (2, fig 1) dimensioned to be received in the user's hand, the other body portion carrying the cutting wheel has a relatively shorter portion (4, fig 1) shaped to accept the user's thumb. The rotary cutting wheel 7 includes an annular body comprising two ramp portions (10a and 10b, fig 5) which converge to define the cutting edge 10. <IMAGE>

Description

CAN OPENER The invention relates to a can opener of the type which operates to separate an end wall or lid of the can by cutting from the outside into the upstanding rim formed at the end of the can and comprising overlapped portions of the perimeter of the end wall and the side wall of the can.

A can opener of this type is disclosed in European patent publication EP-A-169224. That opener comprises two pivotally arranged body portions, one carrying a cutter wheel and the other a traction wheel, and the rim of the can to he opened is in use of the opener received between the wheels. The axes oE the wheels are substantially parallel. A problem can arise with that opener in that even when the opener has cut around the entire periphery of the rim, it can still be difficult to remove the severed end wall. It is proposed in that disclosure to provide means separate from the cutter wheel to detach the severed end wall. For this purpose the opener, in one embodiment, includes an extra release hook, and in another embodiinent, a lever which distorts the side wall of the can.

It is one object of this invention to provide a can opener with means by which the end wall of the can may be severed and simultaneously urged away from the side wall of the can in a single operation, and without the necessity for a specific release means.

This invention is based on the realisation that by appropriate shaping of the parts supporting the rim of the can, the end wall can be cut so that it may be easily detached from the can.

In one aspect the invention provides a can opener adapted to separate an end wall from a can body by cutting from the outside into the upstanding rim formed at the end of the can, the rim cotnprising overlapped portions of the perimeter of the end wall and the side wall of the can, the can opener comprising two body portions arranged for relative pivotal movement, one portion carrying a rotary cutting wheel and the other portion carrying a rotary traction wheel, the axes of the wheels being substantially parallel, the opener being arranged, in use, to receive the rim of the can in between the two wheels and to orbit the can as the traction wheel is rotated while the cutting wheel makes a peripheral cut into the outside of the rim, characterised in that the traction wheel is shaped to distort the rim while it is cut by the cutting wheel to loosen the overlapping engagement between the end wall and the side wall of the can.

Preferably, the traction wheel includes a first portion having a surface adapted to engage, in use, the inner side wall of the ri!n, the said surface being inclined at an angle greater than the angle of the inclination of the rim with respect to the vertical axis of the can, and a second surface arranged, in use, to contact the top surface of the rim.

Most preferably, the first portion comprises an inverted frustoconical portion and the second portion comprises an outwardly extending flange spaced from the frusto-conical portion.

A pair of vertically offset horizontally spaced apart shoulders, separate from the traction and cutter wheels, is preferably resent on one of the body portions of the can opener, the shoulders being arranged, in use, to contact the rim of the can and to orient the riln the relative to the cutting edge of the cutting wheel. One of the shoulders preferably comprises a metal plate to one side of the cutter wheel and the other shoulder comprises a metal pin located on the other side of the cutting wheel.

In another aspect, the invention provides a method of opening a can having an upstanding rim comprising overlapped portions of the perimeter of the end wall and the side wall of the can, the method comprising locating the rim of the can in the space between the cutter and traction wheels of a can opener in which the wheels are each rotatably mounted in one of a pair of pivotally arranged body portions, the traction wheel being shaped to distort the rim while it is cut by the cutting wheel; the method further comprising pivotally closiny the body portions together so that the traction wheel contacts the inner face of the rim to urge the outer face in cutting engagement with the cutter wheel, and rotating the traction wheel thereby to cause the can opener to orbit the can and cut into the outside of the rim while simultaneously distorting te rim sufficiently to loosen the overlapping engagement of the side wall and the end wall of the rim.

In yet another aspect there is provided a hand-held kitchen tool having two co-operating tool parts, the tool comprising two body portions arranged for relative pivotal movement, one of the body portions carrying one cooperating tool part and the other body portion carrying the other cooperating tool part, one of the body portions having an elongate handle portion dimensioned to be received in the palm of the user's hand, the other body portion having a relatively shorter thumb grip portion shaped for engagement by the thumb of tile same hand, the two body portions being pivotally movable between an open condition in which the thumb grip portion extends away and to one side of the handle portion, and a closed condition in which the thumb grip portion lies adjacent the handle portion, each body portion including surfaces which, in the closed condition, oppose one another to limit the extent to which the two body portions can be urged together.

In yet another aspect there is provided a can opener including a rotary cutting wheel arranged to make a cut into a portion of the can to be opened, the rotary cutting wheel including an annular body comprising two ramp portions which converge to define a cutting edge characterised in that the angle of inclination of one of the portions is greater than the other.

In order that the invention may be better understood an embodiment thereof will now be described by way of example, with reference to the accompanying diagrammatic drawings in which: Figure 1 is an underneath plan view of a can opener; Figure 2 is a cross sectional view along line A-A of Figure 1; Figure 3 is a side view of part of the traction wheel shown in Figure 2, but drawn to an enlarged scale; Figure 4 is a cross-sectional view along line B-B of Figure 2; Figure 5 is a view to an enlarged scale of part of Figure 2, but also showing a can rim in the cutting position; and Figure 6a is a partial sectional view showing a can rim before, and Figure 6b is the same view after, cutting using the can opener of Figures 1 to 5.

The can C to be opened, as best seen in Figure 6a, includes a peripheral upstanding rim R, having an upwardly facing topmost portion T and a downwardly facing underside portion U. The rim R is formed from overlapped portions of the periphery of the end wall E of the can and the end portion of the side wall S of the can The can opener shown in the drawings is designed to be held in one hand of a user and comprises a first body portion 1 of relatively large size having a handle portion 2, and a second relatively smaller body portion 3 having a thumb grip portion 4.

The two body portions 1, 3 are separately moulded of plastics and are joined in superimposed pivotal relatioii by means of a spigot 5 on the first portion 1 which projects into a corresponding hole in the second body portion 3.

The two body portions oE the can opener 1, 3 are pivotally movable relative to one another between a relatively closed condition, shown in the drawings, in which the thumb grip 4 lies flush against the handle 2 of the first portion 1 and a relatively open condition, not sliown, in which the tiiumb grip 4 extends away and to one side. The first body portion 1 includes, as shown, a recess 6 in the topmost surface of the handle portion 2 at one side of where the thumb grip 4 lies in the closed condition. When the thumb grip portion 4 is in the closed condition the user can grip the handle 2 with his thumb in the recess and flick the thumb grip sideways from the closed to the open condition.

A cutter wheel 7 is rotatably mounted upon a pin 8 within a recess 9 on the second body portion 3. The cutter wheel 7 includes an annular citing body 10 about midway up its height which protrudes beyond the recess 9, and a lowermost outwardly extending flange 11. The body 10 comprises two ramp portions 10a and lob, Figure 5 which converge to define the cutting edge. The portions are asymmetrical, ie the topmost portion 10a is inclined at a very shallow angle, eg about 5 degrees to the horizontal plane, while the lowermost portion 1Ob is inclined at a relatively steeper angle of between about 45 degrees and 55 degrees to the horizontal plane, preferably about 50 degrees.

Such an arrangement has been found to give a durable cutting edge which requires little force to make a cut. Above the portion 1Oa the cutter wheel includes a further inclined portion 7a to provide a clearance between the cutter and the traction wheel, to be described later on.

A traction wheel 12 includes a pin 13 which extends eccentrically through the spigot 5. The pin 13 rotates within a sleeve 14. A T-shaped handle 15 is secured to the top of the pin 13 for rtatiny tlie traction wheel 12 and a circlip and spring washer arrangement 16 is present in between the lowermost face of the handle 1 5 and the opposing face of the first body portion 1.

The traction wheel 12 comprises an inverted frusto-conical portion 17, best seen in Figure 3, having an included angle X of between about 30 degrees and about 50 degrees, preferably about 40 degrees, so that the contact face thereof makes an angle of between about 15 degrees and 25 degrees with respect to the vertical axis of the can being opened, as will be explained below.

The majority of cans currently available include a rim R having an inner face that diverges from the vertical axis of the can at an angle of about 10 degrees. We have discovered that by shaping the frusto-conical portion 17 of the traction wheel such that the rim R is bent or otherwise moved outwardly at an angle of greater than this angle during cutting, any remaining frictional engagement between the walls of the rim on each side of the cut is broken. The bending action will also tend to break any glue or like sealant present in the rim or, say, a plastics or like lining within the can. Accordingly. the angle of inclination of the portion 17 is selected to be at least greater than about 10 degrees.The maximum angle of inclination should be less than that which so bends the rim that it makes the ttr;itj.on wheel difficult t t() turn, which is of especial importance where the can opener is of the hand operated variety.

The frusto-conical portion 17 includes ribs 13 to provide grip.

A flange 19 of greater diameter is present above the frustoconical portion 17. The flange 19 includes an underlying substantially horizontal annular surface 20. The vertical spacing between the underlying surface 20 and the uppermost face of the flange 11 is selected to be greater than the height of the ri!n on the can to be opened. The underlying surface 20 is joined to the ottternost facing side wall 21 of the flange by an inclined portion or corner 22.The inclined corner 22 comprises an outermost portion 22a inclined at a relatively greater angle Y, e.g. about 45 degrees to the underlying surface 20, and an innermost portion 22b inclined at a relatively smaller angle Z, e.g. about 30 degrees Altilough, as wliown, the two portions are generally planar,. the corner Inay be radinssed or otherwise curved. A pair of vertically offset, horizontally spaced apart shoulders 23, 24, separate from the traction and cutter wheels, best seen in Figures 1 and 4, is present on the underlying face of the second body portion 3.The shoulders 23, 24 contact, in use, the topmost surface T of the rin R and tilt the plane of the can rim relative to the plane of the cutting edge 10 by the so-called dive angle D. One of the shoulders comprises a metal pin 23 projecting towards the traction wheel 12 and disposed so that, when the opener is in the closed condition, the pin 23 is adjacent to and at one side of the point of engagement of the cutter wheel 12 with the rim of the can. The other shoulder 24 comprises an elongate metal plate extending along the outermost edge of the second body portion 3 to the other side of the point of engagement.The relatively wide horizontal spacing of the shoulders 23, 24 makes it easy to finely control the dive angle D while, because the shoulders are of metal, they are resistant to wear A block portion 25 projects downwardly from the second body portion 3, rearwardly of the cutter wheel 7, and includes two circumferentially spaced apart wedge-like surfaces 26, 27 which co-operate with opposing wedge-like surfaces on the first body portion 1 to limit the engagement of the two body parts when in the closed condition, thereby to prevent undue force being applied to the rim and to maintain the horizontal spacing between the traction and cutter wheels at a fixed distance. The horizontal spacing is selected to be comparable to the thickness of the rim being cut, and arranged so that the cutting edge 10 cuts into the outermost layer of the rim only. The two body portions 1, 3 also include interengaging flanges 30 above the wedge-like surfaces 26, 27 to prevent relative twisting of the body portions 1, 3.

In use, the user initially moves the body portions to the open condition and ijitroduces tlle rim R of the can C into the space between the traction and cutter wheels, and then the two body portions are moved in scissor-like fashion towards the closed condition shown ii' the drawings. The shoulders 23, 24 contact the rim R and tilt the can relative to the cutting edge 10 by the dive angle D. The inclined corner 22 of the traction wheel guides the topmost surface T of the rim R downwardly into a position where the frusto-conical portion 17 contacts the inner face of the rim R. The rim of the can is guided along the desired path firstly by inclined surface 22a and then inclined surface 22b.

As the body portions are further moved to the fully closed condition, the cutting edge 10 contacts and then cuts into an upper portion of the outside of the rim R, which is supported on its inner face by the frusto-conical portion 17, while the underside U of the rim R rests upon the flange 11 of the cutter wheel 7. The wedge-like surfaces 26, 27 provide a lock against excess force being applied to the rim and maintain the horizontal spacing between the traction and cutter wheels at a substantially fispd distance.

As the traction wheel 12 is rotated, because of the dive angle, the cutting edge 10 makes a spiral cut which extends vertically downwardly into the riin until the underside U of the rim is lifted from the flange 11 and tlie topmost surface T of the rim is urged ito contact with the underlying surface 20 of the flange 1 9 on the traction wheel 12. The cutting wheel will then continue the rest of the cut, but will remain substantially parallel to the top of the rim with the cutting edge 10 tending to separate the cut edges of the end wall E and the side wall S in the manner of an agricultural ploughshare.The frusto-conical portion 17, in co-operation with the surface 20 and the cutting edge 10, exerts a component of force outwardly and downwardly into the riin thereby to distort or bend the rim R sufficiently to loosen any re)naining engagement that the end wall has with the side wall of the can, as best seen in Figure 5. The opener is then removed from tlie can and the lid is simply pulled off by hand leaving smooth edges.

A comparison of the can rim before and after opening is shown in Figures 6a and 6b. As shown clearly in Figure Gb, after cutting the rim has been distorted just sufficiently that the end wall E may be simply lifted from the can body by simple hand operation and without the necessity for extra tool parts.

The arrangement of the relatively short thumb grip portion 4, and the relatively much longer handle portion'2, restricts the level of leverage on the thumb grip portion 4. This is of advantage in this case where, in the closed condition, it is not desirable to provide too great a compressive force into the rim. Furthermore, the arrangement facilitates single-handed operation, because even in the fully open condition, the two body portions are not too widely spaced apart, which would be the case if the body portions were of substantially equal length.

Claims

1. A can opener adapted to separate an end wall from a can body by cutting from the outside into the upstanding rim formed at the end of the can, the rim comprising over lapped portions of the perimeter of the end wall and the side wall of the can, the can opener co!nprising two body portions arranged for relative pivotal movement, one portion carrying a rotary cutting wheel and the other portion carrying a rotary traction wheel, the axes of the wheels being substantially parallel, the opener being arranged, in use, to receive the rim of the can in between the two wheels and to orbit the can as tie traction wheel is rotated while the cutting wheel makes a peripheral cut into tlle outside of the rim, characterised in that the traction wheel is shaped to distort the rim while it is cut by the cutting wheel to loosen the overlapping engagement between the end wall and the side wall of the can.

2. A can opener according to Claim 1 characterised in that the traction wheel includes a first portion having a surface adapted to engage, in use, the inner side wall of the rim, the said surface being inclined at an angle greater than the angle of the inclination of the rim with respect to the vertical axis of the can, and a second surface arranged in use to contact the top surface of the rim.

3. A can opener according to Claim 2 characterised in that the first portion of the traction wheel comprises an inverted frusto-conical portion and the second portion comprises an outwardly extending flange spaced from the frusto-conical portion.

4. A can opener according to Claim 3 characterised in that the flange includes an inclined portion adapted to guide the rim of the can into the space between the cutting wheel and the traction wheel.

5. A can opener according to Claim 4 characterised in that the inclined portion of the flange comprises an outermost portion inclined at a relatively greater angle to an underlying surface of the flange, and an innermost portion inclined at a relatively smaller angle.

6. A can opener according to any preceding Claim characterised in that the cutting wheel includes an annular cutting edge and an outwardly extending flange is present and disposed below the cutting edge.

7. A can opener according to any of Claims 3 to 6, characteri sed in that the frusto-conical portion of the traction wheel has an included angle of between about 30 degrees and 50 degrees.

8. A can opener according to Claim 7 characterised in that the frusto-conical portion has an included angle of about 40 degrees.

9. A can opener according to any preceding Claim characterised in that a pair of vertically offset, horizontally spaced apart shoulders, separate from the traction and cutter wheels, is present on one of the body portions, the shoulders being arranged, in use, to contact the uppermost surface of the rim at two horizontally spaced apart locations, the vertical offset tilting the plane of the rim, in use, relative to the plane of the cutting edge of the cutting wheel.

1 0. A can opener according to Claim 9 characterised in that one of the shoulders comprises a metal pin mounted on the body portion carrying the cutting wheel, the pin projecting towards the traction wheel to a location adjacent to and at one side of the point where the rim is received in the space between the traction and cutter wheels, the other shoulder comprising a metal plate extending along one edge of that body portion at the other side of the point of engagement.

11. A method of opening a can having an upstanding rim colaprising overlapped portions of the perimeter of the end wall and the side wall of the can, the method comprising locating the ri,n of the can in the space between the cutter and traction wheels of a can opener in which the wheels are each rotatably mounted in one of a pair of pivotally arranged body portions, the traction wheel being shaped to distort the rim while it is cut by the cutting wheel; the method further comprising pivotally closing the body portions together so that the traction wheel contacts the inner face of tlae rim to urge the outer face into cutting engageenent with the cutter wheel, and rotating the traction wheel thereby to cause the can opener to orbit the can and cut into the outside of the rim while simultaneously distorting the rim sufficiently to loosen the overlapping engagement of the side wall and with the end wall of the rim.

12. A hand-held kitchen tool having two co-operating tool parts, the tool comprising two body portions arranged for relative pivotal movement, one of the body portions carrying one co operating tool part and the other body portion carrying the cooperating tool part, one of the body portions having another elongate handle portion dimensioned to be received in the palm of the user's hand, the other body portion having a relatively shorter thumb grip portion shaped for engagement by the thumb of the same hand the two body portions being pivotally movable between an open condition in which the thumb grip por-tion extends away and to one side of the handle portion, and a closed condition in which the thumb grip portion lies against the handle portion, each body portion including surfaces which, in the closed condition, oppose one another to limit the extent to which the two body portions can be urged together.

13. A can opener including a rotary cutting wheel arranged to make a cut into a portion of the can to be opened, the rotary cutting wheel including an annular body comprising two ramp portions which converge to define the cutting edge, cliaracterised in that the angle of inclination of one of the ramp portion is greater than the other.

14. A can opener according to Claim 13, characterised in that one of the ramp portions of the annular body makes an angle of between about 45 degrees and 55 degrees, preferably about 50 degrees to the plane of the cutting edge.

15. A can opener according to Claim 14, characterised in that the other ramp portion of the annular body makes an angle of about 5 degrees to tile plane of the cutting edge.

1 6. A can opener substantially as described with reference to any of the accompanying drawings.

17. A method of opening a can substantially as described with reference to any of the accompanying drawings.