Field of the Invention
[0001] The invention relates to manually operable can openers, and in particular to can
openers of the vertical-cutting and of a laterally-cutting type.
Background to the Invention
[0002] 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.
[0003] 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.
[0004] 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.
Summary of the Invention
[0005] 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.
[0006] 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.
[0007] 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.
[0008] Preferably, the shaft is positioned in an arcuate slot in the head and moves in an
arc.
[0009] Preferably, the shaft moves in an arc of between 25 and 30 degrees.
[0010] 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.
[0011] 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.
[0012] Preferably, said first bevel-gear has fewer teeth than the second bevel-gear, providing
a mechanical advantage for said operating element.
[0013] 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.
[0014] 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.
[0015] Preferably, the cutter blade is rotationally mounted with the body on a cutter axis
oblique to the axis of the shaft.
[0016] 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.
[0017] 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.
[0018] Preferably, the cutter blade is mounted on a pivotal arm connected with the cam-follower.
[0019] Preferably, the arm and cutter blade move in an arc of between 25 and 30 degrees.
[0020] 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.
[0021] Preferably, the first bevel-gear has fewer teeth than the second bevel-gear, providing
a mechanical advantage for said operating element.
[0022] 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.
[0023] Preferably, the cutter blade is rotationally mounted on a cutter axis oblique to
the axis of the traction wheel.
[0024] Further aspects of the invention will become apparent from the following description,
which is given by way of example only.
Brief Description of the Drawings
[0025] Embodiments of the invention will now be described with reference to the accompanying
drawings in which:
Figure 1 illustrates a front side of a can opener according to a first aspect of the
invention, shown in an inoperative condition,
Figure 2 shows the head of the can opener of Figure 1 with the traction wheel removed
to show features there below,
Figure 3 shows the internal drive means of the can opener from the back side in the
inoperative condition,
Figure 4 shows the head portion with the can opener in the operative condition,
Figure 5 shows the internal drive means of the can opener in the operative condition,
Figure 6 shows the front side of a can opener according to a second embodiment of
the invention in an inoperative condition,
Figure 7 shows the internal drive means of the can opener Figure 6,
Figure 8 shows the drive means of the can opener in the inoperative position with
a bevel-gear removed to show features there below,
Figure 9 shows the head portion of the can opener in the operative condition, and
Figure 10 shows the drive means of the can opener in the operative position.
Description of the Preferred Examples
[0026] 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.
[0027] 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 8° 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.
[0028] 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.
[0029] 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.
[0030] Figures 1 - 5 illustrate a first preferred embodiment of the invention. In this embodiment
the can opener comprises a body having a head 10 and a handle 11 extending from the
head 10. The cutter blade 12 is mounted with the body on or adjacent the head 10.
An arcuate slot 16 is located in the face of the head 10 adjacent the cutter wheel.
A shaft 17 is rotationally located within the slot 16 and is movable in a lateral
direction within the slot 16. A traction wheel 13 is fixedly attached to a first end
of the shaft 17 on the face of the head 10 so is to be movable between an inoperative
position and an operative position with respect to the cutter blade 12. The second
end of the shaft 17 located within the head 10. A cam 30 and a first traction wheel
driving gear 18 are affixed to the second end of the shaft 17. Adjacent the cam 30
is an abutment 32 forming a cam surface against which the cam 30 contacts. The shaft
17 is biased in the inoperative position as shown in Figure 2 by a spring such as
a spiral torsion spring or torsion spring 20. As the traction wheel rotates the cam
lobe 31 contacts the cam surface 32 moving the shaft 17 and traction wheel 13 laterally
within the arcuate slot 16 towards the cutter blade 12 to the operative position.
[0031] 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.
[0032] 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 centred 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.
[0033] 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.
[0034] Figures 6-10 illustrate a second embodiment of the invention. In this embodiment
the can opener comprises of body having a head 10 and a handle 11 extending from the
head 10. A traction wheel 13 is mounted on the face of the head 10 and is rotational
by an operating handle 15 located on the side of the head 10 via a pair of engaging
bevel-gears 22, 23. the first bevel-gear 22 is directly coupled to a shaft of the
operating element 15. The second bevel-gear 23 is directly coupled with a shaft 24
mounting the traction wheel 13. The first bevel-gear 22 has fewer teeth and a second
bevel-gear 23 providing a mechanical advantage to the operating element 15. A cam
30 is also engaged with the shaft 24 and is rotational with the traction wheel 13.
[0035] 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.
[0036] 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.
[0037] 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.
1. 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,
a shaft located with the head,
a traction wheel provided at a first end of the shaft.
the shaft 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 on one side of the can opener and supported by the body.
drive means for coupling the operating element and shaft for rotating the shaft by
operation of the operating element,
wherein the shaft is biased in the inoperative position and rotation of the shaft
moves the shaft to the operative position.
2. The can opener of claim 1 further including 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.
3. The can opener of claim 1 wherein the shaft is positioned in an arcuate slot in the
head and moves in an arc.
4. The can opener of claim 3 wherein the shaft moves in an arc of between 25 and 30 degrees.
5. The can opener of claim 3 wherein 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.
6. The can opener of claim 5 wherein 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.
7. The opener of claim 6 wherein said first bevel-gear has fewer teeth than the second
bevel-gear, providing a mechanical advantage for said operating element.
8. The opener of claim 1 wherein 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.
9. The opener of claim 1 wherein 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.
10. The opener of claim 1 wherein the cutter blade is rotationally mounted with the body
on a cutter axis oblique to the axis of the shaft
11. 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.
a traction wheel rotationally mounted with the head,
an operating element on one side of the can opener and supported by the body for rotating
the traction wheel,
the cutter blade 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,
wherein the cutler blade is biased in the inoperative position and rotation of the
traction wheel moves the cutter blade to the operative position.
12. The can opener of claim 11 further including a cam rotational with the traction wheel
and a cam-follower engageable with the cam for moving the cutter lade to the operative
position.
13. A can opener comprising:
a body having an and a handle extending from the head.
a cutter blade mounted with the body on or adjacent the head,
a shaft located with the head,
a traction wheel provided at a first end of the shaft,
the shaft rotational about an axis and movable in an arc 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 on one side of the can opener and supported by the body.
drive means for coupling the operating element and shaft for rotating the shaft by
operation of the operating element, 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.
wherein the shaft is biased in the inoperative position and rotation of the shaft
moves the shaft to the operative position.
14. A can opener comprising:
a body having an head and a handle extending from the head,
a traction wheel rotationally mounted wit the head,
a cam rotational with the traction wheel.
a cam-follower pivotally mounted with the body and engageable with the cam,
a cutter blade mounted with the cam-follower,
an operating element on one side of the can opener and supported by the body for rotating
the traction wheel,
the cutter blade rotational about an axis and pivotal with the cam-follower in a direction
lateral to the axis between an inoperative position in which the traction wheel and
the cutter lade 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.
wherein the cam-follower is biased in the inoperative position and rotation of the
traction wheel moves the cam-follower and cutter blade to the operative position.
15. A can opener comprising:
a body having an head and a handle extending from the head,
a cutter lade mounted with the body on or adjacent the head.
a traction wheel mounted with the body on or adjacent the cutter lade, one of the
cutter blade or traction wheel being 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,
an operating element operable by a user of the can opener for turning the traction
wheel, and operation of the operating element moves the cutter blade and traction
wheel from the inoperative position to the operative position.