NZ282444A

NZ282444A - Can opener with rotary cutter and traction wheels

Info

Publication number: NZ282444A
Application number: NZ282444A
Authority: NZ
Inventors: Joseph Augustine Teren Pereira
Original assignee: Levene Ltd William
Priority date: 1994-01-20
Filing date: 1995-03-21
Publication date: 1999-04-29

Description

<div class="application article clearfix" id="description"> » New Zealand No 282444 International No PCT/GB95/00642 TO BE ENTERED AFTER ACCEPTANCE AND PUBLICATION Priority dates 21 03 1995 Complete Specification Filed 21 03 1995 Classification (6) B67B7/72 Publication date 29 April 1999 Journal No 1439 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION Title of Invention Can opener Name, address and nationality of applicant(s) as in international application form- WILLIAM LEVENE LIMITED, a British company of 167 Imperial Drive, Harrow, Middlesex HA2 7JP, Great Britain WO 96/29276 PCT/GB95/00642 CAN QPSHEB 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 nm formed at the end of the can and compnsing 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 compnses two prvotally arranged body portions, one carrying a cutter wheel and the other a traction wheel, and the nm of the can to be opened is in use of the opener received between the wheels The axes of the wheels are substantially parallel A problem can anse with that opener in that even when the opener has cut around the entire penphery of the nm, 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 embodiment, a lever which distorts the side wall of the can In our International patent application WO 92/02445, we have shown that by appropnate shaping of the parts supporting the nm of the can, the end wall can be cut so that it may be easily detached from the can Accordingly in WO 92/02445 there is provided a can opener adapted to separate an end wall from a can body by cutting from the outside into the upstanding nm formed at the end of the can, the nm compnsing overlapped portions of the penmeter of the end wall and the side wall of the can, the can opener compnsing two body portions arranged for relative pivotal movement about an axis, one portion carrying a rotary Mimosa 0® 43 32 WO 96/29276 PCT/GB95/00642 2 cutting wheel and the other portion carrying a rotary traction wheel, the axes cf the wheels being substantially parallel to each other (and to the main axis of the can body when in position for cutting) in one vertical plane, the opener being arranged, in use, to receive the nm of the can 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 nm, the traction wheel being shaped to distort the nm whi'e it is cut by the cutting wheel to loosen the overlapping engagement between the end wall and the side wall of the can Preferably, to distort the nm, the traction wheel includes a portion having a surface adapted to engage, in use, the inner side wall of the nm, the said surface being inclined at an angle greater than the angle of the inclination of the nm with respect to the vertical axis of the can We have now found that further improvement in the separation of the overlapping engagement of the end wall and the side wall of the can can be achieved by a modification of the shape of the cutter wheel of the can opener disclosed in WO 92/02445 Accordingly the present invention provides a can opener adapted to separate an end wall from a can body by cutting from the outside into the upstanding nm formed at the end of the can, the nm compnsing overlapped portions of the penmeter of the end wall and the side wail of the can, the can opener compnsing two body portions arranged for relative pivotal movement about an axis, one portion carrying a rotary cutting wheel and the other portion carrying a rotary traction wheel, the axes of the wheels being substantially parallel to each other (and to the main axis of the can body when in position for cutting) in one vertical plane, the opener being arranged, in use, to receive the nm of tho can between the two wheels and to orbit the can as the traction wheel is rotated while the cutting wheel makes a penpheral cut into the Mimosa 00 43 32 282444 3 outside of the nm, the traction wheel being 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, abutment means being present to engage the nm of the can at spaced apart locations between the traction wheel and the cutting wheel when the abutment means rest on the can top, characterised in that the cutting wheel includes an angled body portion to abut the nm of the can below the level at which the cutting wheel makes a spiral cut whereby the can is held stable and the cut lid may then be pulled off the body of the can by hand By means of this contact the can is held in a stable position with its mam axis substantially parallel to said axes of the wheels Although the axes of the wheels are substantially parallel in one vertical plane, the cutting head of the cutting wheel may be angled to lie at an angle, preferably of 5 to 12°< to the axes of the traction wheel and the can body in a second vertical plane By this means, the metal of the rim after the cut made by the cutter wheel is encouraged to separate Preferably the angled body portion extends around the entire penmeter of the cutting wheel In an especially preferred embodiment, the angled body portion ends at its lower end in a flange or shoulder around the wheel, the outer face of the flange Deing aligned to extend substantially parallel with the longitudinal axis of rotation of the cutting wheel By appropnate dimensioning of the flange relative to the cutting edge of the wheel, this outer face can abut the side of a can beneath its rim during the cutting operation to stabilise the can 282444 3A Preferably, to distort the rim, the traction wheel includes a portion having a surface adapted to engage, in use, the inner side wall of the nm, the said surface being ^ & ^ ' 282444 WO 96/29276 PCT/GB95/00642 4 inclined at an angle greater than the angle of the inciinabon of the nm with respect to the vertical axis of the can Preferably, rotation of the traction wheel causes passive rotation of the cutter wheel By means of the shaping of the cutter wheel below the cutting penmeter, the can can also be more firmly maintained in the desired relationship without tendency for unwanted rotation or pivoting The cutting wheel obtains c better bias against the can against the more ngid nm than it would against the thinner wall of the can body Embodiments of the invention will now be descnbed by way of example, with reference to the accompanying diagrammatic drawings in which Figure 1 is an underneath plan view of one embodiment of a can opener embodying the invention; Figure 2 is a cross-sectional view along line X-X of Figure 1, Figure 3 is a view to an enlarged scale of part of Figure 2. but also showing a can nm in the cutting position and showing the cutting wheel of the invention in greater detail Figure 4 is a diagrammatic illustration in plan view of a portion of the embodiment shown in Figure 1, Figure 5 is a part-sectional view along line Y-Y of Figure 2, and Figure 6a is a partial sectional view showing a can rim before, and Figure 6b is the same view after, cutting using »he can opener of Figures 1 to 5, Mimosa 09 43 32 WO 96/29276 5 PCT/GB95/00642 The can C to be opened, as best seen in Figure 6a. includes a peripheral upstanding nm R, having an upwardly facing topmost portion T and a downwardly facing underside portion U The nm R is formed from overlapped portions of the penphery 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 compnses a first body portion 1 of relatively large size having a handle portion 2, and a second relatively smaller body portion 3 having a handle gnp portion 4 The two body portions t, 3 are separately moulded of plastics A U-shaped recess in the underside of body portion 2 contains a diec^st metal insert 5 held in position by screws 6 into body 2 A spigot 7 extends from insert 5 through both body portions to join the body portions together in superimposed pivotal relation The two body portions of the can opener 1, 3 are pivotally movable relative to one another between a relatively closed condition, shown in the drawings, in which the handle 4 of body portion 3 lies flush against the handle 2 of the first portion 1 and a relatively open condition, not shown, in which the two handles are moved apart A cutter wheel 8 is rotatably mounted upon a bushing 9 within a recess 9A in the metal insert 5 The cutter wheel 7 includes an annular cutting body 10 which protiudes beyond the recess 9A, and a lowermost outwardly extending flange 11 The body 10 compnses two ramp pojjions 10a and 10b. Figure 3, which converge to define the cutting edge The portions are asymmetrical, i e the topmost portion 10a is inclined at a very shallow angle, e g about 5 degrees to the horizontal plane, while the lowermost portion 10b is inclined at a relatively steeper angle of between about 45 degrees and 65 degrees to the honzontal plane, preferably about 55 degrees. Such an arrangement has been found to give a durable cutting edge Mimosa 09 4'12 WO 96/29276 PCT/GB95/00642 6 which requires minimum force to make a cut Above the portion 10a 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 Below body portion 10, the cutting wheel has a body portion 10c that is angled to project outwardly as it gets further from the cutting edge The angled body portion 10c is pined to tho above-mentioned flange 11 by a shorter, less steeply angled body portion 10d Body portion 10c may be formed at an angle of, for example, from 5° to 20° to the longitudinal rotational axis of the cutting wheel and body portion 10d at an angle of, tor example, from 25° to 35° to that axis i Flange 11 has an outer circumferential face 11a that extends substantially parallel to the longitudinal axis of the cutting wheel A traction wheel 12 includes a pin 13 which extends through the body portion 1 at its end remote from its handle portion The pin 13 rotates within a sleeve 14 AT-shaped handle 15 is secured to the top of the pin 13 for rotating the tracbon wheel 12 and a arclip and spring washer arrangement 16 is present in between the lowermost face of the handle 15 and the opposing face of the first body portion 1 The traction wheel 12 compnses an inverted frusto-comcal portion 17, best seen in Figures The majonty of cans currently available include a nm R having an inner face that diverges from the vertical axis of the can ^t an angle of about 8 to 10 degrees. We have discovered that by shaping the frusto-comcal portion 17 of the traction wheel such that the nm R is bent or otherwise moved outwardly at an angle of greater than this angle dunng cutting, any remaining frictional engagement between the walls of Mimou 0943 32 WO 96/29276 PCT/GB95/MX42 7 the nm on each side of the cut is broken The bending action will also tend to break any glue or like sealant present in the nm or say, a plasties 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 nm that it makes the traction wheel difficult to turn, which is of especial importance where the can opener is of the hand operated variety The frusto-comcal portion 17 includes ribs 18 to provide grip Refemng now to Figures 4 and 5, the underside of body portion 1 is provided with an abutment plate 20 of generally U-shape in plan, the central region 21 of the U-being recessed and apertured to receive the above-mentioned pm 13 Traction wheel 12 is thereby provided centrally of the 'U' and projecting a little below the lowermost plane of the 'U' As shown in Figure 4, cutting wheel 7 lies partly within the open arms of the 'U' when the body portions are in the closed position ana a gap d-d is provided between the two wheels to receive the nm R of a can Abutment plate 20, as shown in Figure 5, defines two opposed end regions 22 being the ends of the arms of tho 'U' When a can is inserted with its nm R between traction wheel 12 and cutting wheel 7 ends 22 rest on top of the can at contact points 23 and 24 and ensure that the axis of the traction wheel is normal to the bd or end E of the can. Downward pressure by these contact points straddling the cutting point is thereby provided across the traction wheel, this being shown as reaction force P/2 at each contact point to counterbalance upward force F incurred dunng cutting Mmosa 09 43 32 W/O 96/29276 PCT/GB95/00642 8 However, it will be appreciated that, due to the curvature of the can. there will be a tendency for the can to tilt as shown in Figure 4, arrow A, because of the offset d-d between forces F and F/2 Angled face 10C of the cutting wheel abuts the nm of the can to prevent this causing unwanted movement As the abutment is against the nm rather than the thin wall of the can, this movement can be opposed without distortion of the can By preventing the can from tilting, the nm is held in a stabilised position so that the cutting edge't 0 can cut at the correct level from the top of the nm As shown, the long.tudinal or rotational axis of the cutter wheel is inclined at an angle 'D' of about 8° to that of the traction wheel and the can body In use, the user initially moves the body portions to the open condition and introduces the nm R of the can C into the space between the traction and cutter wheels, i e cutter gap d-d (Figure 3), and then the two body portions are moved in sossor-Hke fashion towards the closed condition shown in the drawings. As the body porbons 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 nm R, which is ^supported on its inner face by the frusto-comcal portion 17, while the outside of the nm R is engaged by angled body portion 10c below the cut and urged inwardly thereby (Figure 3) The meeting of the handle portions provides a lock against excess force being applied to the nm and maintain the honzontal spacing between the traction and cutter wheels at a substantially fixed distance. As the traction wheel 12 is rotated it dnves the passive cutting wheel and, because of the angle 'D', the cutting edge 10 make a spiral cut which extends vertically downwardly into the nm until the topside T of the nm is bfted away from the lower half of R by body portion 10a The cutting wheel will then continue the rest of the Mimosa 00 43 32 V O 96/29276 PCT/GB95/00642 9 cut, but will remain substantially parallel to the top of the nm with the cutting edge 1 0 tending to separate the cut edges of the end wall E and the side wail S in the nanner of an agncultural ploughshare The faisto-conical portion 17, in cooperation with the cutting edge 10, exerts a component of force outwardly and downwardly into the nm thereby to distort or bend the nm R while the opposite force applied by surface 10c enhances the separation effect on the cut nm Thus the combined forces effectively hold the nm of the can in a stabilised position so that the cutting edge 10 can cut through the outer skin of R and lift the cut portion T The opener is then removed from the can and the lid is simply pulled off by hand leaving smooth edges A companson of the can nm before and after opening is shown in Figures 6a and 6b As shown clearly in Figure 6b, after cutting the nm 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 Mimou 00 43 32 ° 282444 </div>

Claims

<div class="application article clearfix printTableText" id="claims">



CLAIMS 

A can opener adapted to separate an end wall from a can body by cutting from the outside into the upstanding nm formed at the end of the can, the nm compnsing overlapped portions of the perimeter of the end wall and the side wall of the cai^ the can opener compnsing two body portions arranged for relative pivotal movemerit^about^in^is^one+poition carrymg a rotary cutting wheel and the other portion carrymg a rotary traction wheel, 

the axes of the wheels being substantially parallel to each other (and to the mam axis of the can body when m position for cutting) in one vertical plane, 

the opener being arranged, in use, to receive the rim of the can between the two wheels and to 01 bit the can as the traction wheel is rotated while the cutting wheel makes a penpheral cut into the outside of the nn^ 

the traction wheel being shaped to distort the run while it is cut by the cutting wheel to loosen the overlapping engagement between the end wall and the side wall of the can, abutment means being present to engage the nm of the can at spaced apart locations between the traction wheel and the cutting wheel when the abutment means rest on the can top characterised in that the cuttmg wheel includes an angled body portion to abut the nm of the can below the level at which the cutting wheel makes a spiral cut whereby the can 15 held stable and the cut hd may then be pulled off the body of the can by hand 

NZTj' \ - r 

19 SEP 

RtCHiV'ID 

9$ 

o 

II 

282444
2 A can opener according to Claim 1, in which tlie cutting head of the cutting wheel lies at an angle to the axis of the traction wheel and the can body in a vertical plane
3 A can opener according to Claim 2, in which the angle is from 5° to 12° 

s .
4 , 'A can opener according to Claim l^^r^^^lnch^^^Qgled body .portion extends around the entire peniueter of the cutting wheel.
5 A can opener accordmg to any preceding Claim, in which the angled body portion ends at its lower end in a flange or shoulder around the wheel, the outer face of the flange or shoulder being aligned to extend substantially parallel to the longitudinal axis of rotation of the cuttmg wheel,
6 A can opener according to any preceding Claim, m which the traction wheel includes a portion havmg a surface adapted to engage, in use, the inner side wall of the rum the said surface being inclined at an angle greater than the angle of inclination of the run with respect to the verucal axis of the can
7 A can opener according to any preceding Claim, in which rotation of the traction wheel causes passive rotation of the cutter wheel *;8 A can opener accordmg to any preceding Claim, in which the cutter wheel;„ which has an annular cutting body compnsing two ramp portions [x, converge to define the cutting edge, the portions being asymmetrical;1S SEP 1337;t;/ -J;'11 2814 A 4;A can opener according to Claim -8, in which the lcwer ramp portion is inclined at between 45° and 65° to the horizontal plane-and the upper ramp portion is inclined at a shallower angle to the horizontal plane;A can opener according to Claim 5 and 8 or 9, in which the angled body portion is then joined to the flange by a shorter less steeply angled body portion.;A can opener according to any preceding Claim, in which the traction wheel has a frusto conical portion to contact the can nm;A can opener according to claim 1 substantially as herein described or exemplified.;end of claims;ft*0 



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