Patent Application
20050235501
1. Field of the Invention
The invention relates to can openers, and in particular to handheld can openers and to electric-powered can openers. The invention also relates to can openers of the lateral rim cutting type that have a rotational circular traction wheel and a rotational circular cutter blade for engagement with a metal can for removing an end therefrom.
2. Background Information
Many handheld can openers are known. An example of a handheld can opener is in applicant's U.S. Pat. No. 6,058,613 issued on 9 May 2000. This can opener is of the lateral rim cutting type in which a rotational circular cutter blade penetrates a radially outer thickness of metal material comprising a can rim but does not cut completely through the rim whereby the can end may be cut leaving a smooth edge both to the end and the side wall of the can.
A disadvantage of this can opener, and others like it, is that the user must turn a handle/crank to operate it. This can be difficult for people with disabilities affecting the hands or people with weak hands generally such as the elderly.
Electric-powered can openers are known. Most electric can openers are large bench or wall mount types. Handheld electric-powered can openers are known but are typically bulky which make them equally hard to use for people with disabilities or weak hands.
A particular problem with electric-powered can openers is that should the user not stop the opener after it has completely cut the can top it may cause jagged edges or swarf through further cutting action on the already cut can.
It is an object of the present invention to provide a handheld electric-powered can opener which overcomes or ameliorates the above-mentioned problems. A particular object of the present invention is to provide a handheld electric-powered can opener that is compact, easy to hold and easy-to-use.
According to the present invention, there is provided a handheld electric-powered can opener comprising: a body having a hollow handle and a head, a battery and motor provided within the handle, a gearbox coupled to the motor, a rotational traction wheel positioned on or with the head, a rotational cutting wheel positioned on or with the head, a lever positioned with the body and having an operating position for forcing the cutting wheel against a can rim, and a switch for operating the motor when the lever is in the operating position.
Preferably wherein the handle is shaped to fit comfortably in a users hand and to accommodate the battery and motor in tandem.
Preferably the gearbox is a planetary gearbox coupled in tandem with the motor.
Preferably the cutter wheel is coupled to the lever for movement between a first position in which the can rim can be positioned between the cutter and traction wheels and a second position in which the can rim is clamped between the cutter and traction wheels.
Preferably the battery is rechargeable.
Preferably the can opener includes a stand having a holder for supporting the can opener body and a charger for supplying a charge to the battery when the body is supported by the holder.
Preferably the can opener includes a controller for stopping the motor when the can rim has been cut over its circumference.
Preferably the controller stops the motor when a torque on the motor changes.
Preferably the controller stops the motor when a current of the motor changes.
Preferably the controller comprises a control circuit and a current transducer for monitoring motor current and providing a signal to the control circuit representative of motor current.
Further aspects of the invention will become apparent from the following drawings and description.
Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings in which:
Referring to the drawings, a handheld electric-powered can opener 1 includes a body 2 having a hollow handle 3 extending to a head portion 4. The handle 3 is shaped to fit comfortably in a users hand and to accommodate a rechargeable battery pack 5 and motor 6 in tandem. A planetary gearbox 7 is also coupled in tandem with the motor 6 and battery pack 5.
A traction wheel 8 is rotationaly mounted on the head 3 and coupled to the output of the planetary gearbox 7 by bevel gears 9, 10.
A cutting wheel 11 having a blade 15 is rotationaly mounted with the head 3 and coupled to a lever 12. The lever 12 is pivotally mounted to the body 2 and moves the cutter wheel 11 between a first, open, position and a second, operating, position. In the open position a can rim (not shown) can be positioned between the cutter and traction wheels 11, 8. In the operating position the can rim is clamped between the cutter and traction wheels 11, 8 and the cutter wheel 11 is forced against the outer circumference of the can rim cutting through an outer layer of the can material.
Lever 12 has a hole 27 in it. One edge of the hole 27 has a lip 28. A switch 13 and a sliding arm 14 are positioned within the body 2. Arm 14 has a knob 29 projecting orthogonally from body 2. One side of the knob 29 has a grove 30 in it. When the lever 12 is in the operating position, shown in
When the can opener has made one full revolution about the can rim the outer layer of can material will have been cut over its entire circumference. If the motor continues to operate the blade 15 will passed through the gap in the already cut outer layer of can material. As the blade 15 is not doing any significant work motor torque is significantly reduced. Monitoring motor torque, by either mechanical or electrical means, allows a controller to determine when the outer layer of can material around the entire can rim circumference has been cut and stop the motor even though the lever is still in the operating position.
Referring to
A stand 20 includes a holder receptacle 21 for receiving the can opener handle 3 to support the can opener when not in use. The stand 20 also includes a battery charger circuit 22 for supplying a charge to the battery 5 when the can opener is positioned on the stand 20. At the distal end of handle 3 are diametrically opposed electrical contacts 23, 24. The electrical contacts 23, 24 communicate with corresponding electrical contacts 25, 26 located within receptacle 21.
An embodiment of the invention has been described, however it is understood that variations, improvements or modifications can take place without departure from the spirit of the invention or scope of the appended claims. For example, the can opener and its stand may include induction coupling, as commonly found in electric toothbrushes, for the battery charger. And, the rechargeable battery pack may accommodate replacement of rechargeable battery cells with commonly available non-rechargeable batteries.
In a further variation of the present embodiment lever 12 may be arranged to operate switch 13 when it is moved to the operating position. The motor 6 automatically starts when the can rim is clamped between the traction and cutter wheels 8, 11. Lever 12 may be arranged to operate switch 13 by way of a button projecting through handle 3 beneath the lever 12 or a sliding linkage connected to the lever 12 near its pivot point.
Where in the foregoing description reference has been made to integers or elements having known equivalents then such are included as if individually set forth herein.
