Patent Application
20110283551
The invention relates to manually operable can openers, and in particular to can openers of the vertical-cutting and of a laterally-cutting type.
Manually operable can openers have been known for many years and may be broadly categorised into three types: a first type having a cutter blade which cuts directly into the top wall of a can—known as a vertical-cutting type can opener, and a second type having a cutter blade which cuts into the side wall of the can below the rim cuts partially into the rim of a can—known as laterally-cutting type can openers.
A typical can opener comprises first and second elongate operating elements pivotally connected to each other. Each operating element has a handle portion. One operating element has a rotatable traction wheel pivotally opposite its handle, and the other operating element has a cutter blade pivotally opposite its handle. Movement of the handles relative to each other moves the traction wheel and cutter blade between an inoperative position to receive a rim of a can therebetween and an operative position in which the traction wheel and cutter blade engage the rim of the can. During operation of the can opener the two handles must be firmly held together in one hand while an operating handle is turned (to move the can rim between the cutter and traction wheel) with the other hand.
Two problems with the above can opener are that the best position for holding the handles together is often not the most comfortable position for using the opener, and it can be difficult for persons with a weak grip to squeeze the handles together with sufficient force during operation of the can opener to properly engage the can rim between the cutter and traction wheel.
Generally, the invention provides a can opener comprising a body having an head and a handle extending from the head, a cutter blade mounted with the body on or adjacent the head and a traction wheel mounted with the body on or adjacent the cutter blade. One of the cutter blade or traction wheel is movable with respect to the other between an inoperative position in which the traction wheel and the cutter blade are spaced apart so that a rim of a can to be opened may be located between the traction wheel and the cutter blade and an operative position in which the traction wheel and the cutter blade engage a can for opening the can. The can opener also comprises an operating element that is operable by a user of the can opener for turning the traction wheel. Operation of the operating element moves the cutter blade and traction wheel from the inoperative position to the operative position.
According to a first aspect of the invention there is provided a can opener comprising a body having an head and a handle extending from the head and a cutter blade mounted with the body on or adjacent the head. A shaft is located with the head. A traction wheel is provided at a first end of the shaft. The shaft is rotational about an axis and movable in a direction lateral to the axis between an inoperative position in which the traction wheel and the cutter blade are spaced apart so that a rim of a can to be opened may be located between the traction wheel and the cutter blade and an operative position in which the traction wheel and the cutter blade engage a can for opening the can. An operating element is provided on one side of the can opener and supported by the body. Drive means couples the operating element and shaft for rotating the shaft by operation of the operating element. The shaft is biased in the inoperative position and rotation of the shaft moves the shaft to the operative position.
Preferably, the can opener further includes a cam engagement surface and a cam located with the shaft, wherein rotation of the shaft engages the cam with the cam engagement surface thereby moving the shaft to the operative position.
Preferably, the shaft is positioned in an arcuate slot in the head and moves in an arc.
Preferably, the shaft moves in an arc of between 25 and 30 degrees.
Preferably, the drive means comprises a first gear driven by the operating element and a second gear located on the shaft and engaged with the first gear for rotation of the shaft, an axis of the first gear being located at a centre of the arc.
Preferably, the operating element is rotatable about an axis perpendicular to a rotational axis of shaft, the drive means further including a first bevel-gear coupled to the operating element and a second bevel-gear engaging the first bevel-gear and coupled to first gear.
Preferably, said first bevel-gear has fewer teeth than the second bevel-gear, providing a mechanical advantage for said operating element.
Preferably, the shaft is rotatable about an axis perpendicular to a longitudinal axis of the handle, and the operating element is rotatable about an axis perpendicular to the longitudinal axis of the handle and perpendicular to the axis of the shaft.
Preferably, the shaft is rotatable about an axis perpendicular to a longitudinal axis of the handle, and the operating element is rotatable about an axis oblique to the longitudinal axis of the handle and perpendicular to the axis of the shaft.
Preferably, the cutter blade is rotationally mounted with the body on a cutter axis oblique to the axis of the shaft.
According to a second aspect of the invention there is provided a can opener comprising a body having an head and a handle extending from the head. A cutter blade is mounted with the body on or adjacent the head. A traction wheel is rotationally mounted with the head. An operating element is provided on one side of the can opener and is supported by the body for rotating the traction wheel. The cutter blade is rotational about an axis and movable in a direction lateral to the axis between an inoperative position in which the traction wheel and the cutter blade are spaced apart so that a rim of a can to be opened may be located between the traction wheel and the cutter blade and an operative position in which the traction wheel and the cutter blade engage a can for opening the can. The cutter blade is biased in the inoperative position and rotation of the traction wheel moves the cutter blade to the operative position.
Preferably, the can opener further includes a cam rotational with the traction wheel and a cam-follower engageable with the cam for moving the cutter blade to the operative position.
Preferably, the cutter blade is mounted on a pivotal arm connected with the cam-follower.
Preferably, the arm and cutter blade move in an arc of between 25 and 30 degrees.
Preferably, the can opener further includes gearing for mechanically coupling said operating element to said traction wheel, the gearing comprising a first bevel-gear coupled to the operating element and a second bevel-gear engaging the first bevel-gear and coupled to traction wheel.
Preferably, the first bevel-gear has fewer teeth than the second bevel-gear, providing a mechanical advantage for said operating element.
Preferably, the traction wheel is rotatable about an axis perpendicular to a longitudinal axis of the handle, and the operating element is rotatable about an axis oblique to the longitudinal axis of the handle and perpendicular to the axis of the traction wheel.
Preferably, the cutter blade is rotationally mounted on a cutter axis oblique to the axis of the traction wheel.
Further aspects of the invention will become apparent from the following description, which is given by way of example only.
Embodiments of the invention will now be described with reference to the accompanying drawings in which:
The following description is given by way of example only to illustrate the invention and is not intended to limit the scope of use for functionality of the invention. In particular, the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the accompanying drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used is for the purpose of description and should not be regarded as limiting.
Referring to the drawings, the present invention relates to a can opener having a body with a head portion 10 and a single handle member 11 extending from the head 10. The single handle 11 of the current invention is in contrast to many can openers in the art in which the handle comprises a pair of elongate handle elements pivotally connected so as to form “scissor” type handle arrangement. Can openers of the current invention do not have a handle that comprises a pair of pivotally connected elongate handle elements. As is known in the art a cutter blade 12 and traction wheel 13 are rotatable mounted with the body on or adjacent the head 10. The cutter blade 12 is a circular cutter wheel type blade that is rotationally mounted on an oblique shaft 37 such that its axis of rotation is inclined at an angle of between 5° and 10° to the axis of rotation of the traction wheel 13. The traction wheel 13 is of generally cylindrical configuration providing an outer face having a plurality of circumferentially-spaced axially-extending teeth or serrations of substantially equal radius. The traction wheel 13 is coupled to a rotational operating element 14, 15 provided on one side of the can opener and supported by the head 10. The operating element 14, 15 is operable by a user of the can opener for turning the traction wheel 13 either directly where the traction wheel 13 and operating element are on ends of the same stub-shaft or indirectly via coupling gears 22, 23, 18, 19 located internally within the head 10. The operating element may be of various suitable types including, but not limited to, a butterfly-knob type element 14 or a crank-handle type element 15.
In various alternative embodiments of the invention in addition to being rotatably mounted one of the cutter blade 12 or traction wheel 13 is movable laterally with respect to the other between an inoperative position and an operative position. In the inoperative position the traction wheel 13 and the cutter blade 12 are spaced apart from each other by a distance or clearance D1 which is sufficient to accommodate a rim of a can to be opened being located between the traction wheel 13 and the cutter blade 12. In the operative position the distance or clearance between the traction wheel 13 and the cutter blade 12 is less that D1 such that both the traction wheel 13 and the cutter blade 12 engage the can for opening the can. The can opener may be either a rim cutting or end cutting type. In a rim cutting type the cutter blade 12 and traction wheel 13 are positioned in use either side of the can rim to cut an outer metal layer of the can rim to release the (top) end of the can. In the end cutting type the traction wheel 13 engages the rim or can wall while the cutter pierces and end (notionally the top end) of the can to cut the end out of the can.
The cutter blade 12 or traction wheel 13 is made laterally movable by rotationally mounting the blade or wheel on a shaft movable within a slotted journal or opening within the face of the head 10, or by rotatably mounting the blade or wheel to a lever or plate pivotally mounted to the face of the head, or by other suitable means. The cutter blade 12 or traction wheel 13 is biased in the inoperative position such that in an inactive state or prior to use the cutter blade 12 or traction wheel 13 are ready to receive the can between them without fiddling or adjusting by the user. Operation of the operating element 14, 15 by the user is also arranged to cause the cutter blade 12 or traction wheel 13 to move to the operative position as it rotates the traction wheel 13. An eccentric cam 30 is rotationally coupled with the traction wheel 13 such that as the traction wheel 13 is rotated by operation of the operating element 14, 15 the cam 30 is caused to rotate. A cam surface or cam-follower is arranged in contact with the cam 30 and translates rotational movement of the traction wheel 13 and cam 30 into lateral movement of the cutter blade 12 or traction wheel 13. Movement of the cutter blade 12 or traction wheel 13 from the inoperative position to the operative position is caused when the lobe 31 of the cam 30 is in contact with the cam surface or cam-follower. The cutter blade 12 or traction wheel 13 is prevented from returning to the inoperative position during the rotational phase when the lobe 31 is out of contact with the cam surface or cam-follower by way of the bite of the can between the cutter and traction wheel 13 as the user continues to operate the operating element 14, 15 to cut the can rim or end. The biasing spring 20 is provided with sufficient strength to return the cutter blade 12 or traction wheel 13 to the inoperative position when the can rim or end of cut through or no can is engaged between the cutter blade 12 or traction wheel 13, but with insufficient spring strength to overcome the bite of the can between the cutter and traction wheel 13 during the can opening operation.
An operating handle 14 is located on the side of the head 10 and is engaged with a first bevel-gear 22 located within the head 10. The first bevel-gear 22 engages with a second bevel-gear 23 which in turn engages with an intermediary flat gear 19. The traction wheel gear 18 is engaged with the intermediate gear 19 such that rotation of the operating handle 14 transmits rotational movement to the traction wheel shaft 17 via the chain of gears 22, 23, 19 and 17. The first bevel-gear 22 has fewer teeth than a second bevel-gear 23 to provide a mechanical advantage for the operating handle 14.
The intermediate gear 19 is located on a rotational axis 21 that is located to be concentric with the arc-centre C of the arcuate slot 16. As the shaft 17 moves within the arcuate slot 16 the traction wheel gear 17 moves in an arc centered about the axis of rotation 21 of intermediate gear 19 and thus maintains a constant state of mashed engagement with intermediate gear 19 as shaft 17 moves laterally. In the preferred embodiment the shaft 17 moves trough an arc of 25 and 30 degrees, although the arc maybe larger or smaller. A larger arc causes the cutter and blade to move further apart makes it more convenient to receive a can rim between the cutter and blade. An arc of 25 and 30 degrees reflects a compromise between convenience, cost and design constraints.
In the second preferred embodiment the traction wheel shaft 17 is rotatable about an axis that is perpendicular to a longitudinal axis 36 of the handle 11, and the operating element 14 is rotatable about an axis 35 that is perpendicular to the longitudinal axis 36 of the handle 11 and perpendicular to the axis of the traction wheel shaft 17.
A cutter blade 13 is rotationally mounted on a pivoting plate 25 located on the face of the head 10. The plate pivots above the axis 26 through an arc of between 25 and 30 degrees, preferably 27.5 degrees, to move the cutter blade 13 from the inoperative position with respect to the traction wheel 13 and the operative position with respect to the traction wheel 13. The pivot shaft 26 extends through to the inside of the head 10. A cam-follower plate 33 is fixed to the pivot shaft 26 and pivots internally to the head 10 with the pivoting plate 25 to which the cutter blade 12 is mounted. A torsion spring 20 engages with the cam-follower plate 33 to bias the plate 33, and thus pivoting plate 25 and cutter blade 12, towards the inoperative position. The cam-follower plate 33 engages with the cam 30. During rotation of the cam the cam-lobe 31 moves the cam-follower 33 and thus pivot plate 25 and cutter blade 12 from the inoperative position to the operative position engaging a can rim between the blade 12 and traction wheel 13.
In the second preferred embodiment the traction wheel 13 is rotatable about an axis perpendicular to a longitudinal axis of the handle, and the operating element is rotatable about an axis oblique to the longitudinal axis of the handle and perpendicular to the axis of the traction wheel.
Embodiments of the invention have 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.
| Number | Date | Country | Kind |
|---|---|---|---|
| HKS 10101708.9 | Feb 2010 | HK | national |
