US3057059A - Electric can opener - Google Patents

Description

Oct. 9, 1962 M. J. LA FORTE 3,057,059

ELECTRIC CAN OPENER 4 Sheets-Sheet 1 Filed July 3, 1961 Max 4 54 J 142 227;

INVENTOR.

Oct. 9, 1962 M. J. LA FORTE 3,057,059

ELECTRIC CAN OPENER Filed July 5, 1961 4 Sheets-Sheet 2 w & g 2 Q a F" IIIWWIHJUIII 'I Max/4a J lm o/ere- INVENTOR.

BY 7 [/62 6 MM M I M. J. LA FORTE ELECTRIC CAN OPENER Oct. 9, 1962 4 Sheets-Sheet 3 Filed July 3, 1961 Maw/4 J (47 mm;

INVENTOR.

Oct- 9, 19 M. J. LA FORTE 3,057,059

ELECTRIC CAN OPENER Filed July 5, 1961 4 Sheets-Sheet 4 IN VEN TOR.

B Y MIAQ'LIM'KLW dag,

United htates 3,057,059 Patented Oct. 9, 1962 3,957,41'59 ELECTRZC CAN GPENER Michael 3. La Forte, Parir Ridge, ill assignor to Vaughan (10., Chicago, Iii, a corporation of Illinois Filed .Iuiy 3, 1961, Ser. No. 121,746 11 Claims. (Cl. 3tl-4) My invention relates to an improved electric can opener.

Electric can openers have had a sudden wide popular acceptance, and many manufacturers have introduced such openers to meet the public demand. In all that I have seen, however, the designs present certain inconveniences or downright hazards to the users, are difiicult to clean, and use mechanisms carried over from the field of hand powered openers which, While adequate for that purpose, do not take advantage of the inherent characteristics of electric power.

In the electric can openers presently on the market movement of a single lever is normally employed first to anchor the can within the opener and penetrate the top thereof, and second to control the motor to drive the can to shear the top from the can. Release of the opened can is achieved by a reverse movement of the lever. In this operation, the first part of the lever movement, usually from about one-half to three-quarters of the arcuate swing of the lever, achieves the mechanical function of gripping the can and penetrating the can top, and the remaining travel of the lever closes a switch to power an electric motor which drives the driving wheel engaging the can bead. In a lever movement of this sort, the release of the can is achieved by a single throw of the lever.

With such an opener, it is difficult to move the lever to the exact point required to de-energize the motor without moving it a distance only slightly greater which would release the can and result in spillage of its contents. It thus becomes the habit of many operators to maintain a light grip of the can while the can is rotating and its top is being removed, and there have been many instances where the operator has caught her finger between the can and the opener and had it drawn into the opening mechanism.

A major object of my invention is the provision wherein separate controls involving separate manual operations are provided, first, for the penetration of the can top and, second, for starting the can driving motor. Thus, to stop the motor at the end of a can top removal, a certain mechanical action must be performed (in this case the release of a switch button), but the mechanical structure by which the can is locked to the opener in the course of penetration is totally unaffected.

In furtherance of this objective, I contemplate that the can top penetrating linkage sha'll latch at the end of its stroke and that the motor energizing control shall not be operable until the penetrating means is so latched.

Another advantage of major significance arises from the problem that can beads and can sides are uniform neither in width nor height. This problem has been dealt with in manual openers in several ways. Variations in bead thickness have been accommodated by mounting the cutting wheel to float on a spindle and exerting spring pressure on the outer end of the wheel axis to urge it resiliently toward the driving wheel. Variations in bead height have been accommodated by exerting resilient pressure on the plates which bear against the top of the can bead counter to the driving wheel to insure driving contact of the driving wheel with the bead so as to permit a movement of the pressure plates away from the driving wheel. Both of these expedients are such that they must appear on the exposed face of the can opener and, therefore, are subject to the accumulation of dirt and food particles. An electric opener cannot be washed, of

course, as can a hand opener and the preservation of as simple an exterior as possible is greatly to be desired. Likewise the cutter wheel which presents a particular problem of dirt accumulation cannot be removed with any degree of ease from under the spring finger which holds it for separate cleaning.

My invention contemplates a resilient relation between the driving wheel and the cutter wheel to permit movement to accommodate both excessive thickness and excessive height in the bead and also the can seam which is totally enclosed in my opener and which, therefore, permits a simple outer face which is easily maintained in clean and sanitary condition. This mechanism likewise permits a ready removal of both the driving wheel and cutter wheel for cleaning, and upon such removal, leaves an outer face wherein all surfaces having any possible proximity to the can contents are smooth, polished and capable of perfect sanitary maintenance.

In the course of obtaining these advantages of cleanliness I have at the same time provided a novel can penetrating linkage which provides a high degree of mechanical advantage for easy operation. As a part of this same linkage I am able to provide a materially greater spring pressure as between the cutter and driving wheel to take advantage of the torque obtainable from the use of the electric motor to leave the open end of the can smoother and freer from possibly dangerous, raggedly cut edges.

The particular resilient relation between the cutter and the driving wheel has a further advantage. In addition to being stiffer, my spring arrangement is such that a longer relative movement than usual is possible, and a measure of relative twist may occur. With these characteristics, my opener is able to open cans having short radius turns, such as sardine cans and the like, more certainly and more cleanly than other openers I have known.

Other objects and advantages of my invention will be apparent from the following description and drawings of which:

FIG. 1 is a front elevation of a can opener embodying my invention;

FIG. 2 is a side elevation looking at the right side of FIG. 1;

FIG. 3 is a top plan view;

FIG. 4 is a section taken substantially along the line 4-4 of FIG. 3 with, however, the handle in its lower position;

FIG. 5 is a rear elevation showing the opener with the back cover removed;

FIG. 6 is a section taken substantially along the line 66 of FIG. 5;

FIG. 7 is a section taken substantially along the line 7-7 of FIG. 6;

FIG. 8 isan enlarged fragmentary section taken substantially along the line 88 of FIG. 7;

FIG. 9 is an elevation of the inside of the cutter carrier with attached parts shown in phantom;

FIG. 10 is an enlarged fragmentary section taken along the line 1010 of FIG. 7; and

FIGS. 11 and 12 are simplified elevations of the inside of the cutter carrier and associated parts illustrating the relation of the parts in the two end lever positions.

The illustrated embodiment of my opener consists of a plastic case 16 having two pairs of legs 18 secured to the underside thereof for ready removal. At the right hand side of the case a sloping indentation or offset 20 is provided occupying about half the thickness of the case. The indentation has a slot 22 formed longitudinally therein having offset 24 toward the rear of the case at its lower end. Toward the left side of the case a rectangular aperture 26 is provided in the front face 27 thereof. The back of the case may be covered by a plastic or metal sheet hav-.

ing key slots therein (not illustrated) so that the opener may have its legs removed and be hung from a wall.

Considering particularly FIG. 5, I provide integral bosses 28 on the back side of the front face for the reception of screws 30 by which a reduction gear case 32 and attached motor 34 are attached to the case. A metal wear plate 36 is fitted over the bosses 28 to lie flat against the back side of the front face. The wear plate is generally rectangular, but has apertures in its edges to fit over the bosses 28. The wear plate also has a rectangular aperture 38 therein equal in height but narrower than aperture 26 so that the vertical edges 39 thereof extend inwardly of the edges of the aperture in the front face. A cutter carrier 40 is contained in the rectangular apertures 26 and 38 for vertical movement. The carrier projects appreciably above and below the aperture 26, but is proportioned in width to fit slidably within the sides of the aperture.

Viewing the front face of the carrier, an upward and outwardly sloping protrusion 42 is provided at the lower end of the carrier as a guide for the side of a can to be. opened. The carrier has a vertically oriented oval slot 44 formed in about the center thereof. Upward of the slot a cutter boss 46 is formed having a flat circular face 48 which is inclined inwardly downward and to the right (FIG. 1). Boss 46 has a central tapped hole 51} therein for the reception of a screw 52 which mounts rotatably a cutter blade or wheel 54. The cutter wheel and its inclination both downwardly and horizontally are old in the art and are believed to require no further elaboration.

At the upper left hand corner of the outer face of the carrier an ear 56 is formed to which a magnetic can top holder 58 is attached. The can top holder magnet 59 is mounted to an arm 68 which is secured to ear 56 by a screw 62 so that the can top holder may normally occupy the position illustrated in FIG. 2 to engage and catch the top of a can or be pivoted vertically upward to an out-ofthe-way position. To the right of the cutter blade a peg 64 is press-fitted into an appropriate bore to constitute a can head guide.

Viewing the back side of the cutter carrier (FIG. 9), a shallow rim is formed about the sides and top thereof. The side rims 66 are spaced slightly inward of the side edges of the carrier to leave side flanges 67 and the top rim 68 is spaced substantially downward from the top edge of the carrier so as to leave a top flange 70. A mounting block 72 extends centrally from the top rim 68 and has a tapped hole 74 and a locating stud 76 formed thereon. A leaf spring 78 is mounted at its center against the mounting block by screw 80 and is anchored against rotation by an appropriate bore in the spring engaging the stud 76. The spring is bowed forward and the ends 82 thereof thus bear against wear plate 36 on either side of the aperture 26 in the face of the opener.

At the bottom end of the cutter carrier, the metal extends rearward substantially above the bottom edge thereof as at 84 and then downward at 86 to define a channel 88 between the bottom back flange 86 and a bottom front flange 90. The channel 88 is proportioned to embrace loosely the combined thickness of the plastic face 27 and the wear plate 36. The distance between the bottom of channel 88 and the top rim 68 is appreciably less than the height of the aperture 26 in the case face 27. The cutter carrier may thus be vertically reciprocated in the aperture 26 to move the cutter 54 up and down.

To move the cutter carrier and hence the cutter, I provide a boss 92 formed in the lower left corner (FIG. 9) of the cutter carrier between the left side rim 66 and the channel bottom 84, which has a tapped hole therein to receive a screw 94. Screw 94 pivotally secures a cutter closing lever 96 to the carrier. The arm 98 of the lever extends from screw 94 closely adjacent and behind the front face 27 to a point near the slot 22 in the inclined indentation 20 at which point it is offset rearwardly and away from the front face as at 100 and extends through slot 22. A handle 102 is afiixed to the outer end of the arm 98.

A leaf spring 104 is attached at one end to the front side of the lever 96 by a rivet 106 and anchored against rotation by a detent 188. The other end 110 of the spring bears resiliently against the wear plate 36 to urge the lever arm 96 away from the front face 27 of the case. The operating end of the lever is formed to define a cam slot indicated by the bracket 112 (FIG. 11) and a spring finger 114. To provide these elements the operating end 116 of the lever is formed into, generally, the shape of a B. Upwardly of the screw 94 the. lever is blanked out to define a finger extending first upwardly of and away from the arm as at 118 on a curve. Thereafter the finger continues transversely across the blade carrier as at 120 and re-curves down and back up again to terminate in a generally horizontal end 122 which is spaced below and about opposite the center of the horizontal portion 120 of the finger. A projection or thumb 124 is formed to follow the upward and outer curved portion of the finger at a spaced distance from the underside thereof and terminates in a blunt point 126 beside the end 122 of the finger and pointing upwardly toward the horizontal portion 120 of the finger. The end 126 of the thumb desirably approaches slightly more closely the horizontal portion 120 of the finger than does the end 122. Thus, in the analogy to the letter B, the horizontal portion 128 constitutes the upright stem of the letter, the cam slot 112 the upper loop, and the spring finger 114 the lower loop. Again in the analogy, at the point of convergence of the two loops the loops are separate and do not extend to the stem.

The reduction gear case 32 and motor 34 are entirely conventional and need no detailed description. As described before the gear case is mounted on bosses 28 to be spaced slightly back of the lever 96 the cutter carrier 40 and associated mechanism. The gear case has a powered drive shaft 127 extending through the oval slot 44. The shaft 127 has a threaded end 128 on which a conventional, knurled edged can bead driving wheel 130 is threaded. The driving wheel proper thus lies outside the oval slot 44 and in a plane properly spaced with respect to the cutter wheel 54 for can top severance. The gear case 32 also has a forwardly extending peg 132 aflixed thereto to engage in the cam slot 112 of the lever 96.

The operation of this portion of my can opener will be readily understood from the foregoing description. When the can opener is open and ready to receive a can, the lever 96 will be in the position illustrated in FIG. 12; that is, with the handle thereof up and the peg 132 of the gear case lodged in the left hand end of the cam slot 112. This end of the cam slot is nearer the center of rotation (the screw 94) of the lever 96 than the right end thereof. Since the peg 132 is fixed, therefore, the cutter carrier must occupy an upper position and the cutter wheel 54 thus be spaced well above the driving wheel 138. The oval slot 44 permits such movement of the cutter carrier relative to the driving wheel shaft 127 of the gear case 32.

To close the opener on a can, a can is inserted into the opener with the lower edge of the bead resting on the top of the driving wheel 130, and the lever 96 is moved down to the position illustrated in FIG. 11. The camming action of the cam slot 112 upon the stationary peg 132 pulls the cutter carrier downward and brings the bottom edge of the cutter 54 to and through the can top inside the bead and into overlapping relation with the driving wheel 130 in a final relation well known in the art. Powering of the gear case then causes a rotation of the driving wheel to drive the can around to effect a complete severance of the top. The magnetic can top holder 58 engages the top of the can in well-known fashion.

The resiliency inherent in my mechanism is, as stated, to accommodate bulges in the can bead and the can seam and also short radius turns such as might be found in a sardine can, for instance. It will be appreciated that the cutter carrier 40, while secured within the rectangular opening 26 at the lower end thereof by the edges of the channel 88 is free to move outwardly of the opening at the upper end. The restraining force holding the upper end within the opening 26 is the leaf spring 82. Spring 82 may be stiff but at the same time permit a relatively large movement of upper end of the cutter carrier outwardly away from the driving wheel to accommodate a lateral bulge in the bead or a can seam or a short radius turn. The stiffness of the spring tension, of course, will largely determine the smoothness of the inside cut edge of the can, and the high torque of the drive shaft of the driving wheel means that the spring tension may be of a high order to insure such smoothness.

The spring finger 114 accommodates vertical variation in the can bead. When a vertical bulge in the bead is encountered, the tendency is to force a separation of the driving wheel and the cutter. As will be appreciated from FIG. 11, movement of the lever 96 to the closed position removes the rigid thumb from under the peg 132 and places the peg in registry with the free end 122 of the spring finger 114. Thus, when a bulge is encountered, the driving wheel being fixed in location, the tendency will be to raise the cutter wheel and therefore the cutter carrier 40 against the spring pressure of the spring finger 114. The spring pressure desirably is of a high order. A commonly encountered occurrence in can openers is that when a tight turn is attempted, as in the case of a sardine can, the cutter will ride out of the can bead and drop the can or at any rate make an incomplete severance. The relatively great amount of horizontal movement permitted by the leaf spring 82 and the high resistance to vertical displacement provided by the spring finger 114 effectively prevents such occurrences.

Particular attention should be directed to the combined cam slot and spring finger. Since the cam slot is formed by the root or base portion of the spring finger the slot is rigid and lacking in resilience but movement through the cam slot brings the peg 132 into opposition with the designedly resilient spring finger, both being a part of the same member.

Reverting again to the mechanical description of my invention, the motor has a pair of leads 140, 142 thereto one of which 140 is connected to a line cord 144. The other 142 is connected to one blade 146 of a leaf switch 148. The other blade 150 is connected to the line cord 144.

The leaf switch is mounted by an insulating base 152 to a stud 154 provided integrally on the back wall 156 of the diagonal indentation 20. Wall 156 has an aperture 158 therein in line with the free end of blade 150. Blade 150 has an insulating stud 160 secured thereto which extends into aperture 158.

Handle 102 has a transverse aperture 162 therethrough in which a switch button 164 is situated to actuate leaf switch 148. The button consists of a head 166, a shank 168 and a coil spring 170 around the shank biasing the free end of the shank away from back wall 156. The button head is cup-shaped and the edges 172 thereof meet wall 174 inside the aperture 162. Projecting edges on end 171 limit the outward extension of the shank.

The motor switch is operable only when the lever arm 98 is in its lowermost position, with the can top fully penetrated and the can locked between the driving wheel and the cutter. Only at this point is the free end of the button in register with the aperture 158 in the wall 156. Also the movement of the free end of the button is limited by the edges of the head meeting the wall 174. This limit is such that the movement of the button is insufficient to close the contacts of switch 148 unless the lever arm 96 rests in the offset 24 of slot 22 to bring the handle 102 nearer Wall 156. Upon such circumstances being met, however, i.e., the lever arm being engaged in the offset, pressing the button head in will bring the free end 171 thereof into engagement with stud 160 and move leaf 150 into circuit-closing contact with leaf 146 to start the motor.

From the foregoing description it will be appreciated that the can opener of my invention fulfills all of the objectives in particularly satisfactory form toward which my invention is directed. It is safe to operate. There is a minimum possibility of spillage of the contents of cans. First, the two-stage operation of the opener avoids the chance of releasing the can in the course of stopping the opener motor. Second, the novel springing by which the cutter is mounted to the opener case prevents effectively the cutter rolling out of its intended line of travel inside the can bead, regardless of bead irregularity, can seams, or small radius turns. All mechanism aside from the cutter and driving wheel are enclosed in the case, leading not only to a simple and attractive exterior but one which is easily maintained in sanitary condition. It will be noted that both the cutter and driving wheel may be readily removed for cleaning.

It will be likewise appreciated that I have described an embodiment only of my invention and that many structural alternative will undoubtedly readily suggest themselves, and I therefore desire that my invention be regarded as being limited only as set forth in the following claims.

I claim:

1. An electric can opener comprising a driving wheel, a cutter, means mounting one of said members for movement toward the other member to bring said members into overlapping relation and away from the other member, movable means for producing said movement having an end position when said members are in said overlapping position, electric means for driving said driving wheel having a normally open switch in the circuit thereto and switch-closing means on said movable means that is separately movable relative to said movable member, said switch-closing means being positioned to close said switch only when said movable means is at said end position.

2. The combination as set forth in claim 1 wherein said switch closing means lies out of the plane of movement of said movable member and said separately movable means is movable transversely to the plane of movement of said member.

3. An electric can opener comprising a driving wheel member, a cutter member, means mounting one of said members for movement toward the other member to bring said members into overlapping relation and away from each other, a movable member for producing said movement having an end position when said members are overlapping, an electric motor for driving said driving wheel, a normally open switch in the circuit to said motor, means defining a slot guiding said movable member, said slot having an offset therein at said end position of said movable member, means biasing said movable member transversely of said slot toward said offset, said switch being situated to be closed only when said movable member is in said offset.

4. An electric can opener comprising a driving wheel member, a cutter member, means mounting one of said members for movement toward the other member to bring said members into overlapping relation and away from each other, a movable member for producing said movement having an end position when said members are overlapping, said movable member having a switch operator movable at right angles to the plane of movement of said movable member, a wall adjacent the path of movement of said movable member having an aperture therein, an electric motor for driving said driving wheel, a normally open switch to said motor having switch closing means aligned with said aperture, said switch operator being movable into said aperture only when said movable member is in said end position.

5. In the combination as set forth in claim 4 including additionally means defining a slot guiding said movable member, said slot having an offset therein at said end position of said movable member toward said wall, said switch operator being movable into said aperture to close said switch only when said movable member is displaced out of said slot into said offset.

6. An electric can opener comprising a case having a vertical aperture therein, a driving wheel fixed relative to said case, means for operating said driving wheel, a cutter wheel carrier having a cutter thereon mounted in said aperture for vertical movement therewithin to bring said cutter into can-top-penetrating relationship with said driving wheel and to separate said cutter from said driving wheel, a lever pivotally secured to said carrier and having a cam slot therein, and means fixed relative to said case and engaging in said slot to move said carrier upon movement of said lever.

7. The combination as set forth in claim 6 wherein said cutter carrier includes portions in constant engagement with the exterior of said case and a spring resiliently engaging the interior of said case to urge said portions against the exterior of said case.

8. An electric can opener comprising a case, a driving wheel fixed relative to said case, means for operating said driving wheel, a cutter carrier having a cutter thereon mounted for movement on said case to move said cutter toward and away from can-top-penetrating relation with said driving wheel, a lever pivotally secured intermediate its ends to said carrier interiorly of said case, one end of said lever extending through the wall of said case and defining a handle therefor, the other end of said lever having a cam slot therein open at one end, a peg fixed relative to said case and engaged in said slot to move said carrier upon movement of said lever, said lever including resilient means movable into proximity with said peg upon movement of said carrier to said can-top-penetrating position to oppose displacement of said carrier from said position.

9. An electric can opener comprising a case having a front wall, said wall having a vertically oriented aperture therein, a cutter carrier vertically slideable within said aperture and having portions overlapping the outside edges of said aperture, spring secured to said carrier and bearing against the inside surface of said case to retain resiliently said carrier within said aperture, said carrier having a vertically oriented slot therewithin and a cutter wheel thereon above said slot, can driving means secured in fixed position within said case and including a shaft extending through said slot and a can driving wheel on said shaft, and lever means within said case and having an externally operable handle for moving said cutter carrier to move said cutter wheel toward and away from said driving wheel.

10. An electric can opener comprising a case, a driving wheel fixed relative to said case, means for operating said driving wheel, a cutter carrier having a cutter wheel thereon movably mounted on said case for movement into and away from can-top-penetrating relation with said driving wheel, a lever pivotally secured to said carrier, means fixed relative to said case and engaging said lever to move said carrier upon movement of said lever, and switch means operable only when said carrier is in said can-top-penetrating position for energizing said operating means.

11. An electric can opener comprising a case, a driving wheel fixed relative to said case, means for operating said driving wheel, a cutter carrier mounting a cutter wheel above said driving wheel movably secured to said case to move said cutter wheel into and away from cantop-penetrating relation with said driving wheel, a lever having a cam slot therein pivotally secured to said carrier, a peg fixed relative to said case and engaged in said slot to move said carrier upon movement of said lever, said lever including a spring finger having an end opposing said peg when said carrier is in said penetrating position, said end constituting a portion of the wall of said cam slot.

References Cited in the file of this patent UNITED STATES PATENTS 2,286,303 Pearson June 16, 1942 2,570,721 Russell Oct. 5, 1951 2,583,034 Wibling Ian. 22, 1952 2,595,162 Nesster Apr. 29, 1952 2,745,174 Herrick May 15, 1956 2,897,589 Bodle Aug. 4, 1959

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