GB2334939A

GB2334939A - Can opener

Info

Publication number: GB2334939A
Application number: GB9804888A
Authority: GB
Inventors: Shun So
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-03-06
Filing date: 1998-03-06
Publication date: 1999-09-08
Anticipated expiration: 2018-03-06
Also published as: GB9804888D0; HK1020037A1; GB2334939B

Abstract

A can opener comprises a manually rotatable traction wheel (22) and a freely rotatable circular cutter blade (48) wherein the rotational axis of the cutter blade is inclined to the rotational axis of the wheel at an angle of 8? or less. In their in use operative position, the wheel and blade do not overlap and are locatable in opposed relationship about the rim of a can to be opened, the wheel (22) being engageable with a radially inner surface of the can rim and the blade (48) being engageable with a radially outer surface of the rim. In the operative position, the cutter blade (48) penetrates a radially outer thickness of metal material comprising the rim but does not cut completely through the rim whereby the can end (62) may be severed leaving a smooth edge both to the end (62) and the side wall (68) of the can.

Description

CAN OPENER This invention relates to a can opener, which may be of a manually operable type, having a rotatable circular traction wheel and a rotatable circular cutter blade for engagement with a metal can for removing an end therefrom.

Manually operable can openers have been known for many years and may be broadly categorised into two types: a first type having a cutter blade which cuts directly into an end of the can, and a second type having a cutter blade which cuts into the side wall of the can below the rim.

Can openers of the first type have a cutter blade whose axis of rotation is inclined to the axis of rotation of the traction wheel. In this type of can opener, the blade and the wheel are each usually provided with a circular gear whereby in the operative condition of the opener, the gear wheels are in mesh with one another whereby rotation of the wheel by the user in one direction rotates the cutter blade in the opposite direction. In use, the traction wheel engages the rim of a can at the under surface of the rim with the wheel substantially parallel to the longitudinal axis of the can. The cutter blade penetrates completely through and cuts the end of the can at a position slightly radially inwards of the can rim whereby the end is removable upon a complete revolution of the can about its longitudinal axis relative to the opener. Disadvantages of this type of can opener are that metal cuttings and/or other contaminants on the outer surface of the can end may fall into the can during opening. After removal of the can end, sharp edges are present on the can at the radially inner surface of the rim and on the removed can end.

Can openers of the second type have a traction wheel and cutter blade whose axes of rotation are substantially parallel to one another and wherein the wheel and the blade overlie one another to some extent when the opener is in its operative condition. The traction wheel is rotatable by the user and the cutter blade is freely rotatable. In use, the wheel engages the radially inner surface of the can rim with its axis of rotation parallel to the longitudinal axis of the can. The cutter blade penetrates completely through and cuts the side wall of the can slightly below the under surface of the rim whereby the can end and the can rim are removable together upon a complete revolution of the can about its longitudinal axis relative to the opener. Disadvantages of this type of can opener are that metal cuttings can enter the can during opening. After removal of the can end and rim, sharp edges are present on the upper edges of the can side wall. Also, at the time of final separation of the end and rim from the can body, the body may fall and spill its contents if it is not firmly supported by the user.

There has also been proposed a third type of can opener having a cutter blade so disposed relative to the traction wheel that in use, the cutter blade cuts into but not completely through the rim of the can adjacent an end thereof. Cans are generally formed from a cylindrical metal body and two separate metal end caps wherein each end of the body and the outer edge of a respective end cap are folded together to form a sealed closure rim. The rim usually comprises five thicknesses of metal when viewed in cross section being a radially inner, a radially outer and a central thickness of end cap metal, and two intermediate thicknesses of body metal each sandwiched between two of the thicknesses of end cap metal. A can opener with a rim-cutting mechanism of this type is intended in use to cut through the radially outer thickness of metal comprising the rim whereby the remainder of the end becomes releasable from the remainder of the can body leaving a part of the rim in situ on the end and another part of the rim in situ on the body.

It is an object of the present invention to provide a can opener which will overcome at least some of the various disadvantages associated with known can openers.

In accordance with the invention there is provided a can opener comprising a pair of operating elements pivotal with respect to one another, one said element mounting a rotatable traction wheel and the other said element mounting a rotatable circular cutter blade, said wheel and said blade being moveable between an inoperative position in which said wheel and said blade are spaced from one another to an extent that the rim of a can to be opened is locatable between said wheel and said blade, and an operative position in which said wheel and said blade are in close proximity and engageable with a said can to effect opening thereof characterised in that the traction wheel has an outer surface of cylindrical configuration and an axis of rotation which in use is substantially parallel to the longitudinal axis of a can to be opened, and the cutter wheel has an axis of rotation inclined at an angle of 80 or less to the axis of rotation of the traction wheel, said wheel and said blade in said operative position being in opposed non-overlapping relationship with one another and spaced apart at their nearest points by a distance less than the thickness of the rim of a can to be opened whereby, in use in said operative position, said wheel is engageable with the radially inner surface of a said can rim in parallel or substantially parallel relationship with an e;id of the can and said blade is engageable with the radially outer surface of a said can rim to penetrate said rim partially but not completely, rotation of said wheel effecting cutting of said rim by said blade, the penetration of the cut being sufficient to sever a said end from the can.

Preferably there is provided abutment means on the can opener for engagement with the axially outer end of the rim in said operative position thereby in use to enhance maintenance of the orientation of the traction wheel and cutter blade relative to the can. Conveniently said abutment means comprises a pair of spaced apart shoulders which in use abut the axially outer end of the can rim at circumferentially spaced apart positions therealong.

The inclination of the axis of rotation of said cutter blade to the axis of rotation of said wheel causes a force to be applied to a can rim tending to urge the can axially in a direction to maintain the rim between said wheel and said blade during rotation of the blade and wheel relative to one another. Preferably said wheel has a serrated surface to enhance the force applied to a can rim to maintain it between said wheel and said blade.

Conveniently the axis of rotation of said cutter blade is inclined to the axis of rotation of said traction wheel at an angle of substantially 60.

The one operating element which mounts said traction wheel conveniently comprises a planar face and the axis of rotation of said wheel is perpendicular to said fr--ce, and the other operating element which mounts said cutter blade comprises a planar face parallel to the planar face of the other operating element whereby, in use in said operative position, said planar faces are parallel or substantially parallel to an end of a can to be opened. Conveniently the said abutment means comprise a pair of spaced apart shoulders on that operating element which mounts the traction wheel.

Conveniently said wheel is mounted for rotation on an axle member and is driveable for rotation by a drive member mounted on said axle, said drive member comprising a manually operable handle. Conveniently said cutter blade is mounted on an axle member and is freely rotatable relative to its associated operating element.

Said cutter blade may be part of an assembly comprising the said cutter blade and a circular friction wheel rotatable about the same axis of rotation as the cutter blade, said friction wheel being located axially outwardly of said cutter blade relative to the operating element on which they are mounted and being of such a diameter that, in use in said operative position, said friction wheel is engageable with the side wall of a can to be opened below the rim thereof.

Said operating elements are preferably of elongate configuration pivotally connected together and providing handle portions at adjacent ends of said elements for grasping by a user, respective other ends of said elements mounting said traction wheel and said cutter blade.

Said operating elements may includes stop means limiting their relative pivotal movement between said inoperative and operative positions of said traction wheel and cutter blade.

Preferably said wheel and said cutter blade are mounted on said operating elements at respective opposite ends thereof to said handle portions, and said operating elements are pivotally connected together intermediate their ends.

Other features of the invention will become apparent from the following description given herein solely by way of example with reference to the accompanying drawings wherein: Figure 1 is an underneath perspective view of a can opener constructed in accordance with the invention with the traction wheel and cutter blade in their said operative position; Figure 2 is a top perspective view of the can opener of Figure 1 with the wheel and cutter blade in their said inoperative position; Figure 3 is a side elevation partly in cross section showing the can opener in use with the wheel and the cutter blade in their operative position engaged with respective opposite sides of a can rim; Figure 4 is an exploded perspective view of the structural elements of the can opener of the invention; Figure 5 is a bottom plan view of that operating element which mounts the cutter blade thereon; Figure 6 is a cross sectional view on the line A-A of Figure 5; Figure 7 is an end view of the cutter blade and the operating element on which it is mounted; Figure 8 is a cross sectional view of the cutter blade and operating element of Figure 7; Figure 9 is an exploded perspective view of the cutter blade assembly; Figure 10 is a side cross sectional view of the end of the can opener showing the traction wheel and cutter blade in their said inoperative position; Figure 11 is a bottom plan view of the can opener with the traction wheel and cutter blade in their said operative position showing a cover plate with abutment shoulders overlying that end of the operating element mounting the cutter blade, said end of said element being shown in dotted outline; Figures 1 2 and 1 3 are side cross sectional views of the operating handle; Figure 14 is a bottom plan view with the traction wheel and cutter blade in their said inoperative position with the cover plate and handle covers removed; and Figure 1 5 is a similar bottom plan view to that of Figure 14 but with the traction wheel and cutter blade in their said operative position.

The construction of the can opener illustrated herein by way of example will now be described initially with respect to Figures 1, 2 and 4. The opener comprises two operating elements 10 and 1 2 of elongate generally planar form pivotally connected together intermediate their ends by a pivot pin 14 extending through aligned circular apertures 1 6 and 1 8 in said elements and being rivetted over a washer 20. The element 10 mounts a circular serrated traction wheel 22 by means of an axle 24 extending through a circular aperture 26 in the element 10 and through an aperture 28 in a cover plate 30 secured to the under surface of the element 10 whereby the wheel 22 is located at the outer surface of the cover plate 30. The axle 24 extends also through a bushing 32 secured in the aperture 26. The wheel 22 is rotatable by an operating handle 34 keyed to an end of the axle 24 and located on the upper face of the operating element 10. The axis of rotation of the traction wheel 22 is normal to the plane of the adjacent end of the operating element 10 on which the wheel is mounted and as will be appreciated, manual rotation of the operating handle will cause corresponding rotation of the traction wheel. As will be particularly seen from Figure 4, the traction wheel 22 is of cylindrical configuration providing a cylindrical outer face.

The other end of the operating element 10 is shaped to form a handle portion 36.

The other operating element 1 2 is also of generally planar configuration and mounts thereon a cutter blade assembly 38 on an axle 40 inclined at an angle of 8" or less, preferably 60, to the axis of rotation of the wheel 22. The inclination of the axle 40 is provided by an inclined pressed-out portion 42 of the operating element 1 2 having a circular aperture 44 in which the axle 40 is retained whereby the cutter assembly is freely rotatable relative to the operating element 1 2.

The other end of the operating element 12 is shaped to form a handle portion 46.

Referring to Figures 5 to 9, it will be seen that the cutter blade assembly 38 comprises the said axle 40 rivetted to the inclined portion 42 of the operating element, a circular cutter blade proper 48, a circular resiliently deformable plastic friction wheel 50 on which the cutter blade 48 is mounted, a lower bearing washer 52 and an upper metal cover plate 54. The diameter of the friction wheel 50 is preferably slightly greater than the diameter of the cutter blade 48.

Spaced apart abutments in the form of pressed out shoulders or ridges 30a, 30b are provided on the cover plate 30 whereby in use said abutments are engageable with the axially outer end of a can rim at circumferentially spaced apart positions along the rim.

As will be particularly clearly seen from Figures 14 and 15, the operating elements 10 and 12 are pivotable relative to one another between inoperative and operative positions of the traction wheel 22 and cutter blade 48. In Figure 14, the wheel and the blade are shown in their said inoperative position in which a clearance D1 exists between the nearest points of the wheel 22 and blade 48 sufficient to accommodate the rim of a can to be opened. This inoperative position and clearance D1 are defined by an arcuate slot 56 provided adjacent the end of the operating element 1 2 on which the cutter blade assembly 38 is mounted. As will be seen, the axle 24 mounting the traction wheel 22 extends through the slot 56 so that its one end 58 provides a stop means against which the axle 40 may abut to define the inoperative position. The operative position shown in Figure 1 5 is defined by the other end 60 of the slot 56 against which the axle 40 may abut.

In this operative position, a clearance D2 exists between the nearest points of the wheel 22 and blade 48 and this clearance distance is less than the thickness of a rim of a can to be opened.

Referring now to Figure 3 of the drawings, there is shown the can opener with the traction wheel 22 and cutter blade 48 in their operative position in engagement with a can to be opened. As will be seen, in this operative position in use, the wheel 22 is located substantially parallel to an end 62 of a can and spaced therefrom by a distance determined by a cylindrical stop 64 at the outer end of the operating element 10 on which the wheel 22 is mounted for rotation. The outer surface of the wheel 22 engages the radially inner surface of the can rim 66.

The abutments 30a, 30b on the cover plate 30 engage the axially outer end of the can rim 66 thereby to assist in stabilising the can opener relative to the can and to maintain the orientation of the traction wheel and cutter blade relative to the can.

In this in use operative position, the cutter blade 48 penetrates the radially outer surface of the rim 66 but does not cut completely through said rim. The depth of penetration of the cutter blade 48 into the rim 66 is determined by the clearance D2 as described above with reference to Figure 15. The peripheral surface of the friction wheel 50 engages the side wall 68 of the can below the rim 66 and is sufficiently deformable to engage the side wall firmly whilst permitting the cutter blade 48 to penetrate at least through one thickness of the metal comprising the rim.

It will be appreciated that when a can is to be opened, the handle portions 36 and 46 of the opener are separated by the user to their maximum extent thereby positioning the traction wheel 22 and cutter blade 48 in their inoperative position with the maximum clearance D1 between their nearest points. The opener is then positioned over a can so that its rim 66 is between the wheel 22 and blade 48 with the friction wheel 50 below the rim 66. The handle portions 36 and 46 are then grasped by the user and drawn towards one another thereby bringing the wheel 22 and blade 48 into their operative position wherein the cutter blade 48 penetrates into the radially outer surface of the rim 66. Whilst firmly grasping the handle portions 36 and 46 to retain the wheel 22 and cutter blade 48 in their operative position, the user rotates the operating handle 34 which in turn rotates the wheel 22 causing the can to rotate about its longitudinal axis and also causing the cutter blade 48 to rotate and cut into the rim of the can. This operation is continued for a full revolution of the can about its longitudinal axis at which time the handle portions 36 and 46 may be released and the wheel 22 and cutter blade 48 returned to their inoperative position. The can end 62 and a part of the rim 66 are then removable from the can body.

It will be appreciated that the rim of a can is of standard construction and configuration comprising as shown in cross section in Figure 3 three thicknesses of the metal material which forms the end 62 of the can and two thicknesses of the metal material which forms the side wall 68 of the can. Still referring to Figure 3, it will be seen that penetration of the cutter blade 48 through the radially outer thickness of can end material will separate the can end from the rim whereby upon a complete revolution of the can body relative to the opener, the planar part of the can end 62 together with a part of the rim comprising one thickness of material forming part of the can end will be severed from the can body. The remainder of the rim comprising the two thicknesses of side wall material and two thicknesses of can end material will be left attached to the side wall. Thus upon removal of the can end from the can body the upper surface of the can end will be smooth since it comprises the pre-existing turned-over axial end surface of the rim whilst the top end of the side wall of the opened can will also be smooth since it comprises the turned-over metal material which formed part of the rim. An open can can be easily closed by a plastic closure member fitted over the smooth end of the can body thereby to preserve the contents of the can.

During opening of the can a force is imparted tending to move the can towards the opener by virtue of the inclination of the cutter blade 48 relative to the wheel 22.

Upon complete severance of the can end from the can body, the can will remain engaged with the can opener and will not fall off due to the engagement of the friction wheel 50 below the can rim 66, see Figure 3. Furthermore, since the cutter blade does not penetrate completely through the can rim, there is no possibility of metal cuttings or any other contaminant entering the can during opening.

As shown in the drawings, the can opener also includes a bottle opener portion 70 and a blade portion 72.

To assist in removal of the severed end of the can from the body, there is provided a hook element 74 pivotally mounted on the operating element 10. As shown in Figure 11, the hook element 74 is normally retained in a retracted inoperative position as shown in dotted outline and is extendible to its operative position as shown in full outline. In use, after the end of a can has been severed from the body, the hook element 74 is extended and used to lever the severed end completely off the can body.

Claims

CLAIMS: 1. A can opener comprising a pair of operating elements pivotal with respect to one another, one said element mounting a rotatable traction wheel and the other said element mounting a rotatable circular cutter blade, said wheel and said blade being moveable between an inoperative position in which said wheel and said blade are spaced from one another to an extent that the rim of a can to be opened is locatable between said wheel and said blade, and an operative position in which said wheel and said blade are in close proximity and engageable with a said can to effect opening thereof characterised in that the traction wheel has an outer surface of cylindrical configuration and an axis of rotation which in use is substantially parallel to the longitudinal axis of a can to be opened, and the cutter wheel has an axis of rotation inclined at an angle of 8" or less to the axis of rotation of the traction wheel, said wheel and said blade in said operative position being in opposed non overlapping relationship with one another and spaced apart at their nearest points by a distance less than the thickness of the rim of a can to be opened whereby, in use in said operative position, said wheel is engageable with the radially inner surface of a said can rim in parallel or substantially parallel relationship with an end of the can and said blade is engageable with the radially outer surface of a said can rim to penetrate said rim partially but not completely, rotation of said wheel effecting cutting of said rim by said blade, the penetration of the cut being sufficient to sever a said end from the can.
2. A can opener as claimed in claim 1 wherein abutment means are provided on the can opener for engagement with the axially outer end of the can rim in said operative position thereby in use to enhance maintenance of the orientation of the traction wheel and cutter blade relative to the can.
3. A can opener as claimed in claim 2 wherein said abutment means comprises a pair of spaced apart shoulders which in use abut the axially outer end of the can rim at circumferentially spaced apart positions therealong.
4. A can opener as claimed in claim 2 wherein the axis of rotation of said cutter blade is inclined to the axis of rotation of said traction wheel at an angle of substantially 60.
5. A can opener as claimed in any one of the preceding claims wherein the one operating element which mounts said traction wheel comprises a planar face and the axis of rotation of said wheel is perpendicular to said face, and the other operating element which mounts said cutter blade comprises a planar face parallel to the planar face of the other operating element whereby, in use in said operative position, said planar faces are parallel or substantially parallel to an end of a can to be opened.
6. A can opener as claimed in any one of the preceding claims wherein said traction wheel is mounted for rotation on an axle member and is driveable for rotation by;a drive member mounted on said axle.
7. A can opener as claimed in claim 6 wherein said drive member comprises a manually operable handle.
8. A can opener as claimed in any one of the preceding claims wherein said cutter blade is mounted on an axle member and is freely rotatable relative to its associated operating element.
9. A can opener as claimed in any one of the preceding claims wherein said cutter blade is part of an assembly comprising the said cutter blade and a circular friction wheel rotatable about the same axis of rotation as the cutter blade, said friction wheel being located axially outwardly of said cutter blade relative to the operating element on which they are mounted and being of such a diameter that, in use in said operative position, said friction wheel is engageable with the side wall of a can to be opened below the rim thereof.
1 0. A can opener as claimed in claim 9 wherein said friction wheel comprises a resiliently deformable material.
11. A can opener as claimed in any one of the preceding claims wherein said operating elements are of elongate configuration pivotally connected together and providing handle portions at adjacent ends of said elements for grasping by a user, respective other ends of said elements mounting said traction wheel and said cutter blade.
1 2. A can opener as claimed in claim 11 wherein said operating elements include stop means limiting their relative pivotal movement between said inoperative and operative positions of said traction wheel and cutter blade.
1 3. A can opener as claimed in either one of claims 11 or 1 2 wherein said traction wheel and said cutter blade are mounted on said operating elements at respective opposite ends thereof to said handle portions, and said operating elements are pivotally connected together intermediate their ends.
14. A can opener constructed and ananged substantially as hereinbefore described with reference to the accompanying drawings.

14. A can opener constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.

1 5. Any novel feature or combination of features disclosed herein.

Amendments to the claims have been filed as follows 1. A can opener comprising a pair of operating elements pivotal with respect to one another, one said element mounting a rotatable traction wheel and the other said element mounting a rotatable circular cutter blade, said wheel and said blade being moveable between an inoperative position in which said wheel and said blade are spaced from one another to an extent that the rim of a can to be opened is locatable between said wheel and said blade, and an operative position in which said wheel and said blade are in close proximity and engageable with a said can to effect opening thereof characterised in that the tiaction wheel is of generally cylindrical configuration and has an axis of rotation which in use is substantially parallel to the longitudinal axis of a can to be opened, and the cutter blade has an axis of rotation inclined at an angle of substantially 6" to the axis of rotation of the traction wheel, said wheel and said blade in said operative position being in opposed non-overlapping relationship with one another and spaced apart at their nearest points by a distance less than the thickness of the n.m of a can to be opened whereby, in use in said operative position, said wheel is engageable with the radially inner sufface of a said can rim in parallel or substantially parallel relationship with an end of the can and said blade is engageable with the radially outer surface of a said can iim to penetrate said rim partially but not completely, rotation of said wheel effecting cutting of said rim by said blade, the penetration of the cut being sufficient to sever a said end from the can.

2. A can opener as claimed in claim I wherein abutment means are provided on the can opener for engagement with the axially outer end of the can rim in said operative position thereby in use to enhance maintenance of the orientation of the traction wheel and cutter blade relative to the can.

3. A can opener as claimed in claim 2 wherein said abutment means comprises a pair of spaced apart shoulders which in use abut the axially outer end of the can rim at circumferentially spaced apart positions therealong.

4. A can opener as claimed in any one of the preceding claims wherein the one operating element which mounts said traction wheel comprises a planar face and the axis of rotation of said wheel is perpendicular to said face, and the other operating element which mounts said cutter blade comprises a planar face parallel to the planar face of the other operating element whereby, in use in said operative position, said planar faces are parallel or substantially parallel to an end of a can to be opened.

5. A can opener as claimed in any one of the preceding claims wherein said traction wheel is mounted for rotation on an axle member and is driveable for rotation by a drive member mounted on said axle.

6. A can opener as claimed in claim 5 wherein said drive member comprises a manually operable handle.

7. A can opener as claimed in any one of the preceding claims wherein said cutter blade is mounted on an axle member and is fi-eely rotatable relative to its associated operating element.

8. A can opener as claimed in any one of the preceding claims wherein said cutter blade is part of an assembly comprising the said cutter blade and a circular friction wheel rotatable about the same axis of rotation as the cutter blade, said friction wheel being located axially outwardly of said cutter blade relative to the operating element on which they are mounted and being of such a diameter that, in use in said operative position, said friction wheel is engageable with the side wall of a can to be opened below the rim thereof.

9. A can opener as claimed in claim 8 wherein said friction wheel comprises a resiliently deformable material.

10. A can opener as claimed in any one of the preceding claims wherein said operating elements are of elongate configuration pivotally connected together and providing handle poltions at adjacent ends of said elements for grasping by a user, respective other ends of said elements mounting said traction wheel and said cutter blade.

11. A can opener as claimed in claim 10 wherein said operating elements include stop means limiting their relative pivotal movement between said inoperative and operative positions of said traction wheel and cutter blade.

12. A can opener as claimed in either one of claims 10 or 11 wherein said traction wheel and said cutter blade are mounted on said operating elements at respective opposite ends thereof to said handle portions, and said operating elements are pivotally connected together inteimediate their ends.

13. A can opener as claimed in any one of the preceding claims, wherein the outer surface of the traction wheel is serrated.