US3550271A - Automatic can opener - Google Patents

Description

Dec. 29, 1970 R, M ER ETAL 3,550,551

AUTOMATIC CAN OPENER Filed May 29, 1968 3 Sheets-Sheet 1 Dec. 29, 1970 o. R. MEYER ETAL 3,550,271

AUTOMATIC CAN OPENER Filed May 29. 1968 3 Sheets-Sheet 2 five/Mara:

Dec. 29, 1970 D. R. MEYER ETAL AUTOMATIC CAN OPENER 3 Sheets-Sheet 5 Filed May 29, 1968 3,550,271 AUTOMATIC CAN OPENER Donald R. Meyer, Thiensville, and Robert W. Arel, Shorewood, Wis., assignors to John Oster Manufacturing Co., Milwaukee, Wis., a corporation of Wisconsin Filed May 29, 1968, Ser. No. 732,977 Int. Cl. B67b 7/38 U.S. Cl. -4 12 Claims ABSTRACT OF THE DISCLOSURE An automatic can opener having a cutter assembly which is rotatable in one direction to permit loading of the can and in the opposite direction to start the automatic piercing and the continued running of the can opener until the cover is severed from the can, at which time the motor is automatically shut olf. A lost motion connection between the cutting blade and the pivotally mounted cutter support provides a means whereby a single switch actuated by the cutter support energizes the motor to pierce automatically the can cover and maintain the motor in operation until the can is opened.

BACKGROUND OF THE INVENTION As the electric can opener has become an increasingly popular kitchen appliance, it has reached a high state of development. Initially, the electric can opener was little more than a power driven hand can opener. These can openers required the user to manually force the cutter through the top of the can and then maintain a switch in closed position while the can was rotated in engagement with the cutter. A large portion of the can openers sold today represent a considerable improvement over this approach inasmuch as the motor is used to not only rotate the can but also to force the cutter into piercing engagement with the cover. In addition, these improved can openers have means for automatically continuing the motor operation until the cover is completely severed and then automatically deenergizing the motor. The obvious advantage in such an arrangement is that it eliminates the necessity of the user staying by the can opener and holding a switch closed while the cutting operation is continuing.

These more advanced can openers having the power driven piercing feature and the automatic means for controlling the duration of the cutting cycle are sometimes termed automatic can openers while the others are simply electric can openers. While the automatic can openers are considered to be substantially more desirable, the prior art structures for obtaining the automatic feature have been complex and have added considerably to the cost of the can openers. Many of these devices utilize several switches, displaceable support means for the cutting or can rotating assemblies, as well as other complicated SUMMARY OF THE INVENTION The invention is directed to an automatic electric can opener having a cutter supporting assembly which is simply pivotally mounted on the frame of the can opener in much the same way as in the non-automatic electric can openers. The cutting blade supported on the assembly United States Patent O 7 Ice is arranged so that it may be pivoted upwardly when the cutter assembly is rotated to its loading position; and when the cutter assembly is rotated against spring pressure in the reverse direction, a cam on the cutter assembly closes the motor operating switch whereby the can is rotated to pierce automatically the cover with the cutting blade. Continued rotation of the can then produces a reaction force in the cutting blade which retains the cutter assembly in the switch closing position until such time as the cutting operation is completed.

It is an object of the present invention to provide an improved automatic can opener having a single switch operated by a cutter support which is pivoted about a fixed axis with respect to the can rotating means.

It is a further object of the invention to provide an improved automatic can opener having a cutter assembly which is rotatable about a fixed axis to actuate the can rotating means.

It is another object of the present invention to provide an improved can opener having a pivotally mounted cutter assembly which includes a cutting blade mounted thereon with a lost motion connection whereby the support for the cutter blade may permit power piercing of the cover and automatic termination of the can opening cycle through operation of a single switch.

Further objects and advantages of the present invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an electric can opener embodying the present invention;

FIG. 2 is an enlarged fragmentary front elevational View of the can opener shown in FIG. 1 with a portion of the can cover retaining magnet cut away for the purposes of illustration;

FIG. 3 is a vertical sectional view taken on line 33 of FIG. 1;

FIG. 4 is a fragmentary sectional view taken substantially along line 4-4 of FIG. 3 assuming that FIG. 3 shows the complete structure;

FIG. 5 is a greatly enlarged front view of the cutting mechanism of the can opener showing the cutter assembly in the can loading position with the housing cut away to expose the interior parts of the mechanism;

FIG. 6 is an enlarged fragmentary view similar to FIG. 5 but showing the cutter assembly in the starting position prior to the piercing of the cover by the blade;

FIG. 7 is an enlarged fragmentary view similar to FIG. 6 but with the cutting blade in piercing engagement with the cover of the can; and,

FIG. 8 is another enlarged fragmentary front elevational view similar to FIGS. 5 through 7 but with the cutting blade and cutter assembly in the position assumed at the end of the can opening operation.

DESCRIPTION OF THE "PREFERRED EMBODIMENT Referring to FIG. 1, there is shown an automatic electric can opener designated generally by reference numeral 11. The can opener 11 includes a housing 12 formed by a front frame member 13 and a cup-shaped cover 14. The cover 14 is formed with a bottom 15, top 16, and side walls 17 which extend into abutting engagement with the frame member 13 to form an enclosure 18.

Supported within the enclosure 18 is a motor 19 which is in driving engagement with a reduction gear train 20. The gear train 20 and the motor 19 are secured to the frame member 13 which is preferably a rigid, die cast member. The output of the gear train 20 comprises a horizontally disposed output shaft 21, which supports at its outer end a can rotating or feed wheel 23. The wheel 23 is provided with serrations or grooves 23a along the outer periphery so that it may engage the overhanging lip of a can end seam to rotate the can about its own axis. The arrangement of the motor 19, the gear train 20, and the feed wheel supporting shaft 21 and the manner in which these elements are mounted on the frame member 13 are conventional and are described in greater detail in Hubrich Pat. No. 3,254,406, which is assigned to the same assignee as the instant application. Such an arrangement of a shaded pole motor and reduction gearing to drive the can rotating or feed wheel 23 is relatively common in the electric can opener field.

In order to cut a cover from the lid of a can as it is rotated by the wheel 23, there is mounted on the frame member 13 immediately above the feed wheel 23 a cutter assembly 25, which is supported for pivotal movement in a boss 26 formed integrally with the frame member 13. The cutter assembly comprises a cutting blade support 27, a switch cam 28, and a manual operating member 29.

For the purpose of supporting the cutter assembly for pivoted movement in the frame member 13, the cutting blade support 27 is formed with a journal portion 31 which is die cast integrally with a forwardly located support portion 32. Between the support portion 32 and the journal portion 31, there is a shoulder 33 which abuts against the front wall of the frame member 13 and limits the inward movement of the cutter assembly 25.

On the inner end of the journal portion 31, a threaded hole is provided to receive an assembly bolt 34 which bears against a washer 35 to retain the switch cam 28 in its assembled position on the inner end of the journal portion 31. The switch cam 28 is keyed to the journal portion 31 by having a round opening 38 having flatted opposite sides which opening snugly receives a correspondingly shaped portion 36 extending outwardly from the journal portion 31.

As is best shown in FIG. 4, the switch cam 28 is formed with a radially extending projection 37 which is adapted to engage and actuate a switch 40. The switch 40 is fixed to the frame member 13 and includes a fixed contact 41 and a movable contact 42. When the cutter assembly 25 is rotated to the position shown in FIGS. 6 and 7, the radial projection 37 engages the flexible contact member 42 urging it against the fixed contact 41 thus closing the switch. Suitable conductors 43 interconnect the switch contacts 41, 42 in series with the motor 19 which in turn is connected to a suitable power cord 44.

In order to pivot the cutter assembly, it is necessary only to grasp the operating member 29 by an upwardly projecting lever portion 29a and urge the cutter assembly in either direction about its axis. As is best shown in FIG. 5, the operating member 29 is keyed to the cutting blade support 27 by means of an integral slot 29b which is received on cutting blade support 27 and which engages a fiatted portion 45 formed thereon. The operating member 29 is a simple plastic member which is merely slipped into place on the cutting blade support 27 by moving it radially onto the flatted portion of the blade support 27. The operating member 29 is designed to be readily removable by the user so that easy access may be had to the cutter assembly 25 for cleaning purposes. The operating member is also provided with a front shroud portion 290 which is for decorative purposes since it overlies part of the operating mechanism. This shroud portion has been cut away for the purpose of exposing the mechanism behind it in FIGS.5-8 and is therefore only shown in FIGS. 1, 2, and 3.

For the purpose of piercing and cutting the cover of a can, there is provided a cutting blade 47 which is pivotally secured to the forward support portion 32 of the cutting blade support 27. The cutting blade 47 is mounted for pivotal movement on a pin 48 which is displaced from the axis of rotation of the cutter assembly 25, and the opening in the cutting blade 47 receiving the pin 48 is of such'size that the blade 47 may rotate freely thereon. In order to limit the amount of rotation of the blade 47 with respect to the cutting blade support 27, a shoulder screw 49 is threadedly secured to the forward support portion 32.

The shoulder screw 49 has an enlarged flat head 49a, the inner surface of which engages and guides the cutting blade 47, and in addition, the shoulder screw 49 has a shoulder portion 4911 which extends through a clearance opening 47a in the cutting blade 47. As is evident from the various positions of the blades shown in FIGS. 5 through 8, the blade 47 may pivot with respect to the cutting blade support 27, the amount of this pivotal movement being limited by the engagement between the shoulder screw 49 and the opposite ends of the clearance opening 47a. The blade 47 is formed with a downwardly extending cutting edge 47b which terminates at a piercing point 470.

The cutter assembly 25 is arranged so that it may be pivoted by means of the operating member 29 in either one of two directions. In order to retain the cutter assembly in a fixed central position, there is provided a helical spring 50 which has a cylindrical portion received around the supporting boss 26 and has a pair of rearwardly turned projections 50a and 501). These projections 50a and 50b straddle a projecting stop 51 formed integrally with the frame member 13. In addition, the switch cam 28 is formed with a radially projecting dog 52 which lies between the projections 50a and 50b and, in the rest position of the cutter assembly 25, is aligned with the stop 51 on the frame member 13. As a consequence of the projections 50a and 50b being engaged by both the stop 51 and the dog 52, they serve to bias the cutter assembly 25 to a central or fixed position in which the dog 52 and the stop 51 are aligned.

In considering the operation of the can opener and more particularly the cutter assembly 25 in opening a can, reference should be had to FIGS. 5 through 8 in which the blade 47 and the operating member 29 are shown in their various operative positions with respect to a can 53. The can 53 is conventional in form having cylindrical side walls 53a, an end seam 5311, with an overhanging lip and a cover 53c. The serrated feed wheel 23 is adapted to engage the overhanging portion of the end seam 53b to rotate the can about its own axis. In order to permit the can to be loaded into the can opening mechanism with the feed wheel 23 properly positioned with respect to the overhanging lip, it is necessary to withdraw or raise the cutting blade 47 with respect to the feed wheel 23 so that it is no longer in its normal overlapping relation as is shown in FIG. 8. This raising of the cutting blade 47 is accomplished by rotating the cutter assembly 25 clockwise as viewed in FIG. 5 by applying a force to the right against the lever 29a thereby moving the cutter assembly 25 and the blade 47 to the position shown in FIG. 5. In order to be assured that the shoulder screw 49 will be positioned at the upper end of the clearance slot 47a, a stop pin 54 is provided. Under normal circumstances, the blade 47 would assume the position shown in FIG. 5 as a result of its being so positioned at the end of the previous cutting operation. Since in some instances the blade 47 may be bumped during removal of a can or otherwise displaced from the position shown in FIG. 5, it is necessary and desirable to utilize the stop 54 to insure proper positioning of the blade 47 as shown in FIG. 5.

The proper and consistent positioning of the blade 47 as shown in FIG. 5 is important for several reasons. First, it provides a consistent loading position for the can with the point 47c of the blade 47 in engagement with the cover of the can. Secondly, by having the blade 47 positioned as shown in FIG. 5 with respect to the can, proper location of the can is assured during the interval in which the operating member 29 is being moved from the loading to the starting position. Although the stop pin 54 serves as a means of limiting the rotation of the blade 47, a separate stop means 56 formed integrally with the cutting blade support 27 limits the extent of rotation of the cutter assembly 25. As is best shown in FIG. 2, the stop means 56 is a curved flange extending outwardly from the support portion 32 and terminates in radially extending faces 56a and 56b. The stop means 56 is received in an annular recess 57 formed in frame member 13. The recess 57 terminates at either end in radially extending shoulders 57a and 57b which are engaged respectively by faces 56a and 56b to limit the amount of rotary movement permitted in the cutter assembly 25. Thus, the stop 54 is not the means limiting rotation of the cutter assembly but only the blade 47, and accordingly, the force applied between the cutting edge 47b and stop 54 is not sufiicient to dull the blade.

After the can 53 has been properly positioned with the end seam 53b resting on the feed wheel 23, the can cutting cycle may be initiated by moving the lever 29a of the operating member 29 in the opposite direction or counterclockwise as shown in FIG. 6 until such time as the cam projection 37 engages the flexible contact 42 and causes the switch to be closed thereby energizing the motor. At this point in the cycle, the cutting blade 47 is resting with the piercing point 470 engaged against the cover 530 of the can. As the motor 19 is energized causing the feed wheel 23 to rotate clockwise as shown in FIG. 6, the can cover 53 moves into jamming engagement with the blade 47. This action causes the blade 47 to rotate to the position shown in FIG. 7 at the same time piercing the cover 530.

As the can 53 is rotated with the cutting blade 47 in the position shown in FIG. 7, the operator may release the finger pressure on the lever portion 29a, and the cutter assembly 25 will remain in its operative position until the cover 53c is completely severed from the can. During this cutting operation, the can cover exerts a force toward the right as viewed in FIG. 7 against the cutting edge 47b of the blade 47. By virtue of the cutting blade 47 being supported on the pin 48 and having the upper end of the clearance slot 47a in engagement with the shoulder screw 49, the cutting blade 47 exerts a turning force on the cutter assembly 25. This turning force retains the cutter assembly 25 in the position shown in FIG. 7 with the projection 37 engaged with the movable switch contact 42 thereby closing the switch 40. This turning force is in opposition to the force applied by the spring through the projecting ends 50a which tends to urge the cutter assembly back to its central position.

When the cover 53c is completely severed from the can, there is little or no force applied against the cutting blade 47 by the can 53. Accordingly, the turning force applied by the blade 47 is eliminated thereby permitting the cutter assembly 25 to rotate under the influence of the spring 50 back to the central position as shown in FIG. 8. In this position, the projection 37 has moved out of engagement with the movable contact 42 thereby permitting the switch 40 to open deenergizing the motor 19. With the motor 19 deenergized, the feed wheel 23 stops thereby terminating the rotation of the can 53. At the end of the cutting cycle, the can is simply held by the overlapping relationship between the cutting blade 47 and the feed wheel 23 which have the side wall of the can clamped therebetween with the end seam 53b still overlying the feed wheel 23. In order to unload the can from the can opener, it is only necessary to rotate the operating member 29 clockwise as shown in FIG. 8 to the position shown in FIG. 5 in which position the cutting blade is raised or disengaged from the can 53. This permits the can to be readily removed.

For the purpose of retaining the blade 47 in the position relative to cutter assembly 25 as shown in FIG. 8 after the can has been removed, a resilient wave washer 59 is held between the blade 47 and the cutting blade support 27. The washer 59 tends to prevent relative movement between blade 47 and support 27 so that as the operating member 29 is released after removal of a can and the cutter assembly 25 snaps back to the position shown in FIG. 8, the blade 47 will not continue to rotate clockwise with respect to support 27.

The operation of the can opener embodying the invention is simple and effective. The operating lever 29a may be small and compact since it is not used to pierce the cover of the can but only to move the cutter assembly 25 in opposition to the force applied by the spring 50. The cutter assembly is first rotated a small distance in the clockwise direction as shown in FIG. 5 to permit loading of the can. It is then rotated approximately sixty degrees in the opposite direction to begin the can opening cycle. From then on, the can opener operates automatically with the cover being pierced and the motor stopping automatically when the severing of the cover from the can has been completed.

The structure for accomplishing the automatic can opening operation is of about the same complexity as most electric can openers without the automatic feature. A single switch 40 is used to control the entire operation of the can opener. The lost motion connection between the cutting blade 47 and the cutter assembly 25 provides a simple mechanism which makes possible the automatic control of the can opening cycle using the reaction force on the cutting blade 47 as a means of maintaining the operation of the can opener until the cutting of the cover is completed at which time the reaction force is removed thereby terminating the motor operation.

While there has been shown and described several embodiments of the present invention, it is contemplated in the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the present invention.

What is claimed to be new and desired to be secured by United States Letters Patent is:

1. An automatic electric can opener comprising a housing enclosing an electric motor, can rotating means on the outside of said housing for rotating a can about its axis, means drivingly interconnecting said motor and can rotating means, a switch in circuit with said motor to permit selective energization of said motor to drive said can rotating means, a cutter assembly mounted on the exterior of said housing for pivotal movement about a generally horizontal axis, a downwardly extending cutting blade positioned to pierce the cover of a can engaged with said can rotating means, manually operable means for rotating said cutter assembly to a first position with said blade raised upwardly to permit the loading of a can and to a second position in which said blade pierces the cover of the can and said switch is closed by said cutter assembly to drive said can rotating means, spring means biasing said cutter assembly toward said first position when it is in said second position, the reaction force of said blade cutting said cover retaining said cutter assembly in said second position in opposition to said spring means until the cutting of the cover is completed at which time said spring means moves said cutter assembly out of said second position thereby opening said switch, said cutting blade is pivoted to a cutting blade support by a lost motion connection which permits limited pivotal movement between said blade and said support, said manually operable means being connected to said cutting blade support, said switch being actuated by a cam on said cutting blade support when said cutting blade support is in said second position, said lost motion connection permitting said blade to be arrested in its rotary movement by engagement with said can cover while said cutting blade support is rotated to said second position to close said switch, rotation of said can causing said blade to pierce said cover and rotate further to hold said cutting blade support in the said second position.

2. The automatic can opener of claim 1 including means biasing said cutting blade support to an intermediate position between said first position and said second position, said last mentioned means comprising a spring supported by said housing and applying a biasing force against said cutting blade support.

3. The combination of claim 1 wherein said manually operable means comprises a short finger operated lever the inner end of which is slotted to drivingly engage said cutting blade support, a shroud portion on said lever overlying said cutting blade, said lever being readily removable to permit access to said cutter assembly for cleaning purposes.

4. A cutting mechanism for an automatic can opener comprising a can rotating means driven by an electric motor, manually operable means for selectively controlling a switch for energizing said motor, a cutting blade movable by said manually operable means into piercing engagement with the can being rotated to form a continuous cut in the cover as the can is rotated, a mechanical connection between said manually operable means and said blade including a lost motion connection, said manually operable means being movable to a switch closing position, biasing means urging said manually operable means out of said switch closing position, said lost motion connection permitting said cutting blade to rest in non-piercing engagement with said cover with said manually operable means in said switch closing position, rotation of said can by said can rotating means causing said cutting blade to pierce the can cover and take up the lost motion so that the cutting force on the cutting blade as the can is rotated retains said manually operable means in the switch closing position, upon removal of said cutting force said biasing means rotating said manually operable means out of said switch closing position.

5. The combination as set forth in claim 4 wherein said manually operable means is rotatable to move said cutting blade to a raised position to permit a can to be engaged with said can rotating means, said biasing means urging said manually operable means out of the position for raising said blade to an intermediate position in which said blade engages said cover.

6. The combination as set forth in claim 5 wherein said manually operable means being biased to said intermediate position when said manually operable means is biased out of said switch closing position upon removal of said cutting force, said cutting blade overlies said can rotating means in the intermediate position of said manually operable means at the end of the can opening operation whereby the can wall is held securely between the cutting blade and the can rotating means after the motor has been shut oil.

7. The combination of claim 5 having a stop to engage said cutting blade when said manually operable means is rotated to raise said cutting blade, said stop preventing further rotation of said cutting blade in a direction of said manually operable means to the limit permitted by said lost motion connection.

8. A cutting mechanism for an automatic can opener comprising a can rotating means driven by an electric motor, a cutter assembly including a cutting blade support mounted for pivotal movement about a horizontal axis and a cutting blade carried by said support, said cutting blade being positioned eccentrically with respect to said axis whereby pivotal movement of said support raises and lowers said cutting blade, switch actuating means supported on said cutting blade support, a single switch operated by said switch actuating means to control said motor, a manual operating member on said cutter assembly for rotating said cutting blade support and for moving said switch actuating means into a switch closing position, said cutting blade engaging the cover of a can at a point spaced below said axis whereby the reaction force on said blade resulting from cutting the can cover urges said cutter assembly into said switch closing position until the cutting of said cover is completed, and spring biasing means pivotally urging said cutting blade support in a direction opposite to said reaction force to rotate said switch actuating means to a switch open position when said cutting is completed.

9. The combination of claim 8 wherein said cutter assembly closes said switch to start said can rotating means prior to said blade having pierced said cover, rotation of said can with said blade in engagement with said cover causing further rotation of said blade in a direction caus ing it to pierce the cover.

10. A cutting mechanism for an automatic can opener comprising a can rotating means driven by an electric motor, a cutter assembly including a cutting blade sup port mounted for pivotal movement about a horizontal axis and a cutting blade carried by said support, said cutting blade being positioned eccentrically with respect to said axis whereby pivotal movement of said support raises and lowers said cutting blade, at single switch operated by said cutter assembly to control said motor, a manual operating member on said cutter assembly for moving said cutter assembly into said switch closing position, said cutting blade engaging the cover of a can at a point spaced below said axis whereby the reaction force on said blade resulting from cutting the can cover urges said cutter assembly into said switch closing position until the cutting of said cover is completed, said cutter assembly closing said switch to start said can rotating means prior to said blade having pierced said cover, rotation of said can with said blade in engagement with said cover causing further rotation of said blade in a direction causing it to pierce the cover, said cutting blade is pivotally supported on said cutting blade support and a lost motion connection between said cutting blade support and said blade permitting only limited pivotal movement therebetween.

11. The combination of claim 10 wherein said lost motion connection is operative to permit rotation of said blade between its position in non-piercing engagement with said can cover to a cutting position in which it severs the cover from the can as it is rotated, said cutting blade support remaining in position to close said switch throughout the movement of said blade between said non-piercing position to said cutting position.

12. The combination of claim 11 wherein said cutting blade is pivoted about a point displaced from the axis of said cutting blade support, a clearance slot formed in said cutting blade in an area spaced from the pivotal mounting of said blade and stop means on said blade support extending through said slot and permitting limited pivotal movement of said blade with respect to said blade support.

References Cited UNITED STATES PATENTS 2,979,815 4/1961 Rohde 30-4 ANDREW R. JUHASZ, Primary Examiner G. F. GRAFEL, Assistant Examiner US. Cl. X.R. 30-8.5

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