US 2803057 A
Description (OCR text may contain errors)
2 Sheets-Sheet 1 Filed Sept. 6. 1956 W WNM R. LMEADER KITCHEN APPLIANCE Aug. 20, 1957 2 Sheets-P5115 2 Filed Sept. 6. 1956 INVENI'OR WW 11 454059,
rronwmrs United States Patent KITCHEN APPLIANCE Ralph I. Meader, Takoma Park, Md.
Application September 6, 1955, Serial No. 532,595
11 Claims. (Cl. 304) This invention relates to a power operated kitchen ap pliance. In particular, the invention is directed to a motorized can opener.
The objects of the invention are to produce an automatic safety electric switch for a kitchen appliance; to produce a motorized or power driven can opener; to produce a can opener which automatically punctures the lid of a can and then cuts the lid from the can; and to produce a can opener having safety features in its operation.
In general, these objects are obtained by pivotally mounting a plate containing the cutter blade upon a suitable stand. This stand also contains a suitable power source which through reduction gears drives the toothed can turning wheel. A handle lever is attached to the plate for pivoting the same and an electric switch is adapted to be engaged by the handle lever. When the can is placed in position beneath the cutter blade, downward movement of the handle lever will first bring the cutter blade into engagement with the lid of the can, and further movement of the handle lever by applied positive pressure actuates an electric switch to set the can-engaging wheel in motion. This wheel seizes the can and rotates the can with the lid in contact with the cutter blade to first puncture the lid, and then continue to rotate the can to cut the lid loose from the can. Upon release of the pressure on the handle lever, the motor is stopped, and upon lifting the handle lever, the cutter blade is left free of the lid.
The means by which the objects of the invention are obtained are described more fully with reference to the accompanying drawings, in which:
Figure 1 is a perspective view of the motorized can opener;
Figure 2 is a side elevational view partially in section of Figure 1;
Figure 3 is a front view of the can cutting mechanism in open position;
Figure 4 is a similar view in closed position;
Figure 5 is a rear view of the cutter plate; and
Figure 6 is a cross section on the line 6-6 of Figure 2.
The can opener is composed of a base 2, upon which is mounted the stand 4. This stand contains any suitable power means, as an electric motor, which through reduction gearing generally indicated at 6 drives a shaft 8 to which is joined a toothed can turning wheel 10.
Mounted on the face of stand 4 is a plate 12 upon which is fixed a cutter blade 14, this blade being of a conventional form for can openers. Plate 12 functions as an arm and is secured to stand 4 by a pivot screw or bolt 16 which is offset to the left from the vertical plane passing through the center of plate 12. It has been discovered that pivot 16 should, for best results, be offset at an angle of 22% from the vertical plane passing through the axis of wheel in the direction of the rotation of the wheel. Any substantial variation in this angle interferes with the sure penetration of blade 14 into the 0 lid of the can, and the lifting of the blade after the cut has 7 been completed.
Patented Aug. 20, 1957 Wheel 10 is fixed to a shaft extending through an and ate slot 20 in plate 12 by means of a detailed construction to be later described. A second arcuate slot 22 lies below slot 20 through which the stop screw 24 is set to limit the movement of plate 12 in one direction or the other.
As best shown in Figure 5, on the back side of plate 12 is the shaft 30 forming part of a handle 34 exposed to the right outwardly of stand 4. Shaft 30 is connected to plate 12 by a pivot bolt 36 which lies substantially below pivot 16. The shaft extends across plate 12 and is connected by a cross arm 38 to handle 34. Adjacent cross arm 34 is a screw 40, note Figures 3 and 4, which projects through an arcuate slot 42 in plate 12, and secured to shaft 30, in order to provide for a slight excess movement means for shaft 30.
Also mounted upon the rear of plate 12 is an electric switch 50 of conventional design having a button 52 adapted to be contacted by shaft 30. Leads 54 run from switch 50 to a power means, such as an electric motor mounted within stand 4.
Adjacent switch 50 the spring element 60 is secured to plate 12, which has a plunger 62 which must be depressed by shaft 30 before shaft 30 engages switch button 52. A second spring element 64 connected to a second switch may be mounted above shaft 30, which is engaged by shaft 30 when handle 34 is lifted should it be desired to reverse the motor.
Cross arm 38 is movable through an arcuate slot 76 in stand 4. Handle 34 is connected to cross arm 38 by members 72 extending through apertures 74 in stand 4.
In Figure 6 wheel 10 is provided with a collar on the rear side of plate 12 to hold wheel 10 in place in slot 20. A rectangular stub shaft 82 projects from collar 8 into a complementary slot in shaft 8. This enables plate 12 and its associated elements to be removed from stand 4 simply by unfastening screws 16 and 24.
In operation, the mechanism is initially in open position as shown in Figure 3. As in a normal can opener, the rim of a can is thrust upwardly until it contacts blade 14. Handle 34 is then depressed which, by means of screw 40 contacting one end of slot 42, rotates plate 12 on pivot 36 and brings the rim of the can into contact with the teeth of wheel 10 and in a position for cutting. Further downward movement of handle 34, which is very slight, causes shaft 30 to overcome the pressure of spring plunger 62, and then to contact switch button 52 in order to activate the electric motor. Wheel 10 then begins to move, and in its initial movement, first causes blade 14 to puncture the lid. This is because the upward pressure given to the lid by wheel 10 is opposed by the downward pressure of the blade 14, and the can lid is seized between the two. As the can starts to rotate, there is such a frictional drag between the point of the blade and the lid under the pull of the motor as to cause the blade to bite into the lid, and thus puncture the same. This puncturing movement is permitted by the play afforded by slots 22 and 42. As the wheel continues to rotate, the lid is cleanly cut from the can. As soon as the can has been revolved one revolution, and the lid freed, handle 34 is released and the action on spring plunger 62 raises shaft 30 by screw 40 rising in slot 42, to stop the electric motor instantaneously. Further raising of handle 34 pulls blade 14 clear of the can, and the operation is completed.
This power driven can opener has the principal advantage in that the lid of a can is punctured by power, and the cutting of the lid is then continued by power without any loss of time. Consequently, can lids are quickly and cleanly cut from the can. In addition, the mechanism is of simple construction, and the plate 12 can be easily removed for purposes of being cleaned or repaired. Further features lie in the safety factors in that the electric switch elements are concealed from the outside, and the motor cannot be activated unless sufficient positive pressure is maintained upon handle 34 to overcome the pressure of spring plunger 62.
Having now described the means by which the objects of the invention are obtained, I claim:
1. A can opener comprising a stand, a toothed can turning wheel mounted on said stand, power means for turning said wheel, a plate pivotally mounted on said stand and lying in a plane substantially parallel to the plane of said wheel, a can cutting blade secured to said plate, a handle fastened to said plate with limited pivotal movement with respect thereto and for rotating said plate and cutting blade into cooperative can precutting position with respect to said turning wheel, and switch means on said plate for energizing said power means and actuated by further movement of said handle after said handle has brought said plate and blade into said can precutting cooperative position, whereupon said turning wheel rotates the can to seize the knife to puncture and then cut the can.
2. In a can opener having a toothed can turning wheel and a can opening blade, power means for turning said wheel, and means for bringing said blade into engagement with a can for first puncturing and then cutting said can by the turning of said wheel by said power means.
3. In a can opener as in claim 2, further comprising handle means for bringing said blade into cooperative precutting position with respect to said wheel, and switch means actuatable by said handle means for activating said power means before bringing said blade into can puncturing and cutting position.
4. In a can opener as in claim 3, further comprising means for activating said switch means only upon positively sustained pressure upon said handle means.
5. In a can opener as in claim 2, said blade bringing means further comprising pivot means mounting said blade for swinging said blade arcuately into contact with said can at an angle at which said blade drags through said can.
6. In a can opener as in claim 5, further comprising means supporting said wheel and blade in substantially the same plane, and said pivot means being offset at an angle of about 22V2 from a vertical plane passing through the axis of said wheel.
7. A can opener comprising a plate, a can opening blade secured to said plate, a first slot in said plate beneath said blade, a toothed can turning wheel fixed to a shaft extending through said slot, a support means for pivotally mounting said plate upon said support, a handle pivotally secured to said plate, a second slot in said plate, means connected to said handle and extending through said second slot to limit movement of said handle relative to said plate, and switch means contactable by said handle upon its movement to substantially one end of said second slot.
8. A can opener as in claim 7, said means for pivotally mounting said plate further comprising a pivot screw extending through said plate into said support and offset at an angle of about 22V2 from a vertical plane passing through the axis of said wheel.
9. A can opener as in claim 8, said wheel further comprising a toothed portion on one side of said plate, a collar portion on the other side of said plate, and a stub shaft projecting from said collar portion, and drive shaft means for detachably engaging said stub shaft.
10. A can opener comprising a support, a toothed can turning wheel mounted on said support for rotation on a fixed horizontal axis, power means for turning said wheel, an arm carrying a can cutting blade having an inclined cutting edge adapted to be brought into engagement with the lid of a can, a pivot fastening said arm to said support above said wheel and offset from and lying above the axis of said wheel, and means for swinging said arm about said pivot for first bringing said blade into contact with the lid and then puncturing and cutting the lid as said blade is dragged into the lid by movement of the lid as the can is turned by said Wheel.
11. A can opener as in claim 10, said pivot further being fastened to said support at an angle of about 22V2 from a vertical plane passing through the axis of said wheel in the direction of the rotation of said wheel.
References Cited in the tile of this patent UNITED STATES PATENTS 1,939,349 Holman Dec. 12, 1933 2,532,898 Drugman Dec. 5, 1950 2,555,931 Raab June 5, 1951