GB2289033A

GB2289033A - Can opener

Info

Publication number: GB2289033A
Application number: GB9408917A
Authority: GB
Inventors: Soe Aung
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-05-05
Filing date: 1994-05-05
Publication date: 1995-11-08
Also published as: GB9408917D0; WO1995030621A1; AU2317395A

Abstract

A can opener includes cutter wheels 5, 6 for cutting a part of a can 50 to be opened to remove the lid. The cutter wheels, in addition to cutting the can, grip the can to cause relative movement between the can and the can opener on rotation of the cutter wheels. The cutter wheels may be serrated, and arranged to cut alternative interleaving series of serrations, the interleaving series combining to effect a continuous cut on relative movement of the can and the can opener. There may be two cutter wheels, and these may be rotated by means of a handle 18 coupled to the cutter wheels by means of gear wheels. Locating means which may comprise a wheel adapted to engage the rim of a can are provided for locating a can to be opened adjacent the cutter wheels. <IMAGE>

Description

CAN OPENER The present invention relates to a device for opening a can, such as is commonly used for storing foodstuffs.

A conventional can opener, as shown in Fig. 1 comprises a single cutter blade, which may be circular or knife shaped, attached a first crank shaped lever.

A second crank shaped lever carries a toothed wheel and is hinged to the first crank shaped lever. In use, the cutter blade is located on the upper surface of the tin can near its outer periphery and the toothed wheel is located below the protruding rim of the can. Pressure is applied to handles on the crank shaped levers to bring them together and cause the cutter blade to pierce the upper surface of the can and to cause the toothed wheel to grip the lower edge of the rim.

Rotation of the toothed wheel by turning the handle causes the device to move around the top surface of the can, thereby cutting a slot, until the top surface can be removed.

A relatively large amount of pressure must be applied to to the crank handles to cause the cutter to pierce the upper surface, and to cause the toothed wheel to grip the rim sufficiently. This leads to wear of the toothed wheel, and to blunting of the cutter.

This pressure also creates frictional forces which impede operation of the device. On the other hand, the toothed gear wheel is liable to slip if insufficient pressure is used.

The present invention seeks to provide a can opener which is easier to operate, and less prone to wear.

Accordingly, the present invention provides a can opener comprising two cutter wheels for cutting a part of a can to be opened, means for rotating at least one of the cutter wheels, and locating means for locating the can to be opened adjacent the cutter wheels.

Typically, the locating means is on a first arm pivotally joined to a second arm on which the cutter wheels are rotatably mounted, and typically the arms are cranked.

Preferably, the cutter wheels are adapted to grip a can to be opened, thereby to cause relative movement of the can to be opened and the can opener on rotation of the cutter wheels. The cutter wheels preferably cut the lid of a can to be opened.

Desirably, each cutter wheel cuts a series of serrations in the lid of a can to be opened, and is arranged so that the series interleave to effect a continuous cut on relative movement of a can to be opened and the can opener.

Preferably, the cutter wheels have a serrated circumference.

Typically, the means for rotating the cutter wheels comprises a handle coupled to a first gear wheel, the first gear wheel being arranged to engage further gear wheels coupled respectively to each of the cutter wheels.

Preferably, the gear wheel coupled to the handle is the same size as each gear wheel coupled to a cutting wheel.

Typically, the locating means comprises a locating wheel having a smooth surface adapted to engage a surface, preferably the lower surface, of the rim of a can to be opened.

Preferably, the locating wheel is rotatably mounted on a bearing, and more preferably, the bearing is lubricated.

Preferably, the cutting wheels are located on an arm adapted to fit around the edge of a can to be opened.

Embodiments of the present invention will now be described, by way of example, with reference to the following drawings, in which: Fig. 1 is a view of a prior art can opener; Fig. 2 is a view of an embodiment of the present invention in use; Fig. 3 is a view of the embodiment shown in Fig. 2 in the direction of the arrow A; Fig. 4 is a partially cutaway view of the embodiment shown in Fig. 2, in the direction of the arrow B; Fig. 5 is an enlarged front view of a cutter wheel shown in Fig. 2; Fig. 6 is an enlarged side view of a cutter wheel shown in Fig. 2; Fig. 7 is an enlarged front view of a gear wheel shown in Fig. 2; Fig. 8 is an enlarged side wheel of a gear wheel shown in Fig. 2; Fig. 9 shows an axial section of the locating wheel depicted in Figs. 3 and 4; Fig. 10 is a view of an alternative embodiment of the present invention;; Fig. 11 is an enlarged front view of a cutter wheel shown in Fig. 10; Fig. 12 is an enlarged side view of a shaft on which a cutter wheel is mounted; Fig. 13 is an enlarged side view of the shaft on which the handle is mounted; Fig. 14 is an enlarged side view of the pivot which joins the cranked arms.

As can be seen in Fig. 2, in use, the can opener 1 is placed on a can 50, with first and second cutter wheels 5,6 adjacent the rim 51 of the can 50, and bearing on the top surface 52 of the can. As shown in Fig. 3, there is a locating wheel 10 rotatably mounted via a bearing 11 on a cranked arm 20 for engaging a lower edge of the rim 51 of the can 50. The cutter wheels 5,6 rotatably mounted on a second cranked arm 21 are arranged to cut into the lid 52 of the can 50.

As can be seen from Fig. 4, the cutter wheels 5,6 are coupled via respective shafts 7,8 to gear wheels 15,16. The shafts 7,8 are shown more clearly in Fig. 12. A further gear wheel 17 intermeshes with both gear wheels 15,16, and is coupled to a handle 18 by a shaft 38. Thus, rotation of the handle 18 causes cutter wheels 5,6 to rotate by means of gears 15,16,17 and shafts 7,8. The handle 18 is rotatably mounted on the second cranked arm 21 by shaft 38. The shaft 38 is illustrated in Fig. 13.

The cranked arms 20,21 are joined together at a pivot 22, thereby allowing the cutter wheels 5,6 to be moved with respect to the locating wheel 10. The pivot 22 is illustrated in Fig. 14. The cranked arms 20,21 have handle portions 23,24 (which may be covered or shaped for ease of grip) for applying pressure to bring the cutter wheels 5,6 closer to the locating wheel 10, to pierce the lid 52 of a can 50. The handle 18 has ears 19 for applying pressure to rotate the handle.

As can be seen in Figs. 5 and 6, the cutter wheels 5,6 can be formed as toothed wheels, having a serrated circumference, and have a square central cutout, for attaching to the respective shafts 7,8.

Thus each cutter wheel 5,6 will cut a series of serrations. The rotation of each cutter wheel 5,6 is coupled, and the distance between them set so that the series of serrations cut by each cutter wheel 5,6 interleave on movement of the can 50 relative to the can opener 1.

As shown in Figs. 7 and 8, the gear wheels 15,16 also have a square central cutout for attaching to the shafts 7,8. In this way, rotation of the gear wheels 15,16 can be transmitted via the shafts 7,8 to the cutter wheels 5,6.

Typically, the cutter wheels 5,6 have a central portion 25,26 having a diameter of 14 mm, and a thickness of 6 mm. The square central cutout typically has a side of 4 mm. The overall diameter including the teeth 27,28 is approximately 22 mm. Typically, each cutter wheel 5,6 has 8 teeth 27,28. Typically, the axial thickness of each tooth 27,28 is about 2 mm at the point 29,30 from where the tooth is tapered to a sharp edge.

In an alternative embodiment, shown in Fig. 10, the cutter wheels 5,6 have a front view as shown in Fig. 11. In this embodiment, the central portions 25,26 of the cutter wheels 5,6 have diameters of approximately 8 mm. The teeth 27,28 have a circumferential width of approximately 4 mm, and extend away from each other at an angle a of approximately 330. The axial thickness of thy teeth 27,28 is approximately 2 mm up to the points 29,30 (at a diameter of approximately 14 mm) from which the teeth taper to a sharp edge.

The gear wheels 15,16 typically have an overall diameter at the widest portion of 19.5 mm, and the gear wheels have an outline which is a frusto-conical section, the generating cone having an angle of 7.50.

The thickness of the gear wheels is typically 6 mm, and they have a square cutout having sides of approximately 6.35 mm. There are 18 teeth. Since the square cutout in the gear wheel 15,16 generally has a different size to that in the cutter wheels 5,6, the shafts 7,8 will not have a uniform cross-section. This assists in locating the gear wheels 15,16 and the cutter wheels 5,6 on respective sides of the cranked arm 21.

As can be seen from Fig. 9, the locating wheel 10 has an enlarged circular portion, having a diameter of approximately 16 mm, and a thickness of approximately 1 mm. This narrows via a tapered portion of approximately 3 mm thickness to a smaller diameter circular portion having a diameter of approximately 8 mm, and a thickness of approximately 3 mm. This is joined to a still narrower circular portion having a thickness of approximately 6 mm, and a thickness of approximately 3 mm. The locating wheel 10 has a central bore for mounting on the bearing 11.

The can opener is usually constructed out of a metal, such as steel, but other materials may be substituted. For example, rigid plastics material or aluminium alloy may be used for the gear wheels 15,16,17. The cutter wheels 5,6 may be made of a hardened material, such as a hardened steel.

In use, the locating wheel 10 is positioned adjacent a side of a can 50, below the rim 51 of the can 50. The cutter wheels 5,6 are located above the lid 52 of the can 50, radially inside the rim 51.

Pressure is applied to handle portions 23,24 of the cranked arms 20,21 to cause teeth 27,28 of the cutter wheels 5,6 to pierce the lid 52 of the can 50.

Rotation of the handle 18, by pressure applied to ears 19 rotates gear wheel 17, which in turn causes cutter wheels 5,6 to rotate via gear wheels 15,16 and shafts 7,8. Rotation of the cutter wheels 5,5 cause the can 50 to be moved relative to the can opener 1.

Each of the teeth 27,28 on the cutter wheels 5,6 cuts a slit in the upper surface 52 of the can 50.

The series of slits cut by the teeth 27 on the first cutter wheel 5 interleaves with the series cut by the teeth 28 on the second cutter wheel 6 to effect a continuous cut on passage of the can opener 1.

As can be seen, the can 50 is moved relative to the can opener 1 by rotation of the two cutter wheels 5,6. The locating wheel 10 does not need to contribute to causing this relative movement, and can be smooth.

Additionally, since the teeth 27,28 pierce the lid 52 of the can, the movement is effected positively without relying on friction alone.

Claims

CLAIMS:

1. A can opener comprising cutter wheels for cutting a part of a can to be opened, means for rotating at least one of the cutter wheels, and means for locating a can to be opened adjacent the cutter wheels.

2. A can opener according to claim 1, wherein the cutter wheels are adapted to grip a can to be opened, thereby to cause relative movement of the can to be opened and the can opener on rotation of the blades.

3. A can opener according to any one of the preceding claims, wherein the cutter wheels have a serrated circumference.

4. A can opener according to any one of the preceding claims, wherein the cutter wheels are arranged to cut alternate interleaving series of serrations in a can to be opened, the alternate series effecting a continuous cut on relative movement of a can to be opened and the can opener.

5. A can opener according to any one of the preceding claims, wherein the means for rotating the cutter wheels comprises a handle coupled to a first gear wheel, the first gear wheel being arranged to engage further gear wheels coupled respectively to each of the cutter wheels.

6. A can opener according to any one of the preceding claims, wherein the locating means comprises a locating wheel having a smooth surface adapted to engage the rim of a can to be opened.

7. A can opener according to claim 6, wherein the locating wheel is rotatably mounted on a bearing on the first arm portion.

8. A can opener substantially as herein described, with reference to Figs. 2-14 of the accompanying drawings.

Amendments to the claims have been filed as follows CLAIMS: 1. A can opener comprising cutter wheels for cutting a part of a can to be opened, means for rotating at least one of the cutter wheels, and locating means for locating a can to be opened adjacent the cutter wheels, the cutter wheels being adapted to grip a can to be opened to cause relative movement of the can to be opened and the can opener on rotation of the cutter wheels.

2. A can opener according to claim 1, wherein the cutter wheels have a serrated circumference.

3. A can opener according to any one of the preceding claims, wherein the cutter wheels are arranged to cut alternate interleaving series of serrations in a can to be opened, the alternate series effecting a continuous cut on relative movement of a can to be opened and the can opener.

4. A can opener according to any one of the preceding claims, wherein the means for rotating the cutter wheels comprises a handle coupled to a first gear wheel, the first gear wheel being arranged to engage further gear wheels coupled respectively to each of the cutter wheels.

5. A can opener according to any one of the preceding claims, wherein the locating means has a locating wheel adapted to engage the rim of a can to be opened.

6. A can opener according to claim 5, wherein the locating wheel has a smooth surface.

7. A can opener according to claim 5 or claim 6 wherein the locating wheel is rotatably mounted on a bearing.

8. A can opener according to any one of claims 5 to 7, wherein the locating wheel is mounted on a first arm portion, and the cutter wheels are rotatably mounted on a second arm portion, the first and second arm portions being coupled together to allow relative movement therebetween.

9. A can opener substantially as any one herein described, with reference to Figs. 2-14 of the accompanying drawings.