Cutlery – Can opener – With driven roller to continuously engage bead and...
Reexamination Certificate
2002-12-24
2004-12-14
Choi, Stephen (Department: 3724)
Cutlery
Can opener
With driven roller to continuously engage bead and...
C030S418000, C030S422000, C030S424000
Reexamination Certificate
active
06829832
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a can opener, more particularly a can opener, which has a single handle, and which is relatively easy to assemble, and can be manufactured with necessary precision relatively easily.
2. Brief Description of the Prior Art
Can openers that have handles operable in laid-down position and are used for cutting the annular sides of cans are among various can openers commercially available. Can openers that have handles operable in laid-down position and are used for cutting the annular sides of cans can be made to consist of a single handle.
Referring to
FIG. 6
, a popular conventional can opener
2
with a single handle includes a handle
21
, a cutting wheel
22
, a transmission shaft
23
, and a rotary lever
26
. There are U-shaped rod
24
, and a curved projection
25
provided on an inner side of a front end of the handle
21
, which are to be pressed against corresponding parts of a can to locate the handle
21
. The cutting wheel
22
extends out between the U-shaped rod
24
and the curved projection
25
from the inner side of the handle
21
. The transmission shaft
23
is passed through the front end of the handle
21
. Connected to the inner end of the transmission shaft
23
is the traction wheel
231
, which is to be pressed against an inner side of an end cover of a can for making the can to move relative to the cutting wheel
22
when the rotary lever
26
is operated; the rotary lever
26
is connected to the other end of the transmission shaft
23
so that the user can turn the rotary lever
26
to effect rotation of the shaft
23
and the traction wheel
231
. Thus, when the rotary lever
26
is turned, a can engaged with the can opener is forced to move relative to the cutting wheel
22
, and an upper annular side of the can is severed by means of the cutting wheel
22
.
Referring to
FIG. 7
, an exploded perspective view of the above can opener, formed on the front end of the handle
21
is a stepped hole
211
for the shaft
23
to pass through; the stepped hole
211
has a bigger inner end for holding a sleeve
232
and a spring
233
. The transmission shaft
23
has a locating hole
234
formed across the outward end thereof; the locating hole
234
is formed by means of drills. Fitted around the outward end of the shaft
23
is a hexagonal member
27
, which has opposite gaps
271
at an outward end, and slopes
272
facing the gaps
271
. The rotary lever
26
has a hexagonal hole
261
in the middle. There are adjustment pads
236
fitted around the shaft
23
and disposed between the outward side of the handle
21
and the hexagonal member
27
for adjusting the distance between the traction wheel
231
and the blade of the cutting wheel
22
with. After the shaft
23
is passed through the spring
233
, the sleeve
232
, the stepped hole
211
, the adjustment pads
236
, and the hexagonal member
27
, an adjustment pin
235
is passed through the locating hole
234
of the shaft
23
with two ends thereof being held in the opposite gaps
271
of the hexagonal member
27
; referring to
FIGS. 8
, and
9
, if the lever
26
is not turned in the cutting direction, the ends of the adjustment pin
235
will be pressed against lower ends of the slopes
272
of the hexagonal member
27
owing to the spring
233
. The rotary lever
26
is joined to the hexagonal member
27
at the hexagonal hole
261
. Thus, the traction wheel
231
can be made to stay in a not-action position farther away from the cutting wheel
22
when the ends of the adjustment pin
235
are pressed against the lower ends of the slopes
272
.
When the U shaped rod
24
and the cutting wheel
22
are pressed against corresponding portions of a can and when the lever
26
is turned in the cutting direction, i.e. counterclockwise in the FIGS., the hexagonal member
27
will first be turned relative to the adjustment pin
235
so that the ends of the adjustment pin
235
are pressed against the higher ends of the slopes
272
instead, and in turn, the shaft
23
is made to slide outwards and the traction wheel
231
is pressed against the inner side of the annular portion of the can cover. Thus, the upper annular lateral side of the can can be severed by means of the cutting wheels
22
when the user continues to turn the lever
26
in the cutting direction to move the can relative to the cutting wheel
22
.
This can opener is convenient to use, however, it is found to have disadvantages as follows:
1. It is relatively difficult to drill across the shaft
23
to make the locating hole
234
because the shaft
23
is cylindrical, and drills used in the drilling process are prone to be diverted or to break, causing defect rate to increase and endangering the workers. Consequently, the manufacturing cost is relatively high.
2. The shaft
23
is usually made of relatively hard steel that has large proportion of carbon; therefore, it is difficult to make the locating hole
23
in predetermined position with precision.
3. Should the locating hole
234
be not formed in such a manner that an axis thereof and that of the shaft
23
intersect and perpendicular to each other, those portions of the shaft
23
that are beside the locating hole
234
will not be the same, and strength of the shaft
23
is reduced. And, the locating hole
234
is prone to be formed off the predetermined position. Consequently, workers have to spend time in finding adjustment pads with suitable thickness for offsetting the errors, otherwise the traction wheel
23
can't be engaged with the inner side of the annular portion of the can cover with proper pressure, and the smoothness of the cutting operation can be reduced.
4. It is necessary to round off two ends of the locating hole
234
for allowing the adjustment pin
235
to be inserted through the locating hole
234
easily. However, a drill used for the rounding-off process is prone to be diverted because the ends of the locating hole
234
curve together with the lateral side of the shaft
23
; when the drill comes into contact with the convexly curved portions of the ends of the hole
234
, it can't move smoothly. In addition, the ends of the locating hole
234
have to be polished manually after the rounding-off process, causing increase of manufacturing cost. The adjustment pin
235
is very smooth on the surface therefore it is likely to fall off the locating hole
234
in assembly causing trouble to the laborers.
SUMMARY OF THE INVENTION
It is a main object of the present invention to provide a single-handle can opener, which is equipped with an adjusting mechanism capable of being easily manufactured and assembled.
It is another object of the present invention to provide a single-handle can opener, which can be provided with precision in respect of the space between the cutting wheel and the traction wheel, either in the action position or in the not-action position.
It is yet another object of the present invention to provide a single-handle can opener, of which the adjusting mechanism can't become loose during the course of the rotary lever is turned in the cutting direction to open a can.
The present can opener is equipped with an adjustment element instead of the pin of the prior art, and the shaft is formed with threads on the outward end portion instead of the locating hole of the prior art. The adjustment element is screwed onto the outward end of the transmission shaft, and has two wing portions in contact with the sloping portions of the hexagonal member so that the sloping portions can effect reduction of the space between the traction wheel and the cutting wheel upon rotational operation of the lever in the cutting direction.
REFERENCES:
patent: 3277570 (1966-10-01), McLean
patent: 3345742 (1967-10-01), McLean
patent: 3781989 (1974-01-01), Swetlitz et al.
patent: 3983625 (1976-10-01), McLean
patent: 4050155 (1977-09-01), Pitocchi
patent: 4236428 (1980-12-01), Feamster, III
patent: 4782594 (1988-11-01), Porucznik et al.
patent: 5367776 (1994-11-01), C
Alston Technologies Development Co., Ltd.
Choi Stephen
Rosenberg , Klein & Lee
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