US3706135A

US3706135A - An electrically powered can opener

Info

Publication number: US3706135A
Application number: US87053A
Authority: US
Inventors: Masao Fukunaga; Kiyoyuki Amo
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1969-11-08
Filing date: 1970-11-05
Publication date: 1972-12-19
Anticipated expiration: 1989-12-19
Also published as: CA941147A

Abstract

An electrically powered can opener comprising cutter blade operable by manually operated actuator which is operatively connected with cam plate operable to close electric switch for motor for driving feeding gear which in turn rotates and feeds can to be opened so that the latter is urged into cutting engagement with cutter blade. A spring is provided between cutter blade and actuator to allow same to have limited downward lost motion relative to cutter blade so that manual force on actuator is not required to drive cutter blade into cover of can. The spring holds cutter blade in engagement with opened can so that cutter blade cooperates with feeding gear to pinch edge of opened can.

Description

United States Patent Fukunaga et al.

[54] ELECTRICALLY POWERED CAN OPENER [72] Inventors: Masao Fukunaga, lchioka, Minatoku, Osaka; Kiyoyuki Amo, Amagasaki-shi, both of Japan [73] Assignee: Matsushita Electric Industrial Co. Ltd., Osaka, Japan [22] Filed: Nov, 5, 1970 [2l] Appl. No.: 87,053

[30] Foreign Application Priority Data Nov. 8, 1969 Japan ..44/89465 Nov. 8, 1969 Japan ..44/89466 Nov. 8, 1969 Japan ..44/89467 Nov. 8, 1969 Japan ..44/89468 Nov. 8, 1969 Japan ..44/89469 [52] U.S. Cl. ..30/4 R [5 l] Int. Cl. B67b 7/38 [58] Field of Search ..30/4 A, 4 R, l0, ll

[451 Dec.V 179, 1972 Primary Examiner-Robert C. Riordon Assistant Examiner-Gary L. Smith Attorney-Stevens, Davis, Miller & Mosher [57] ABSTRACT An electrically powered can opener comprising cutter blade operable by manually operated actuator which is operatively connected with cam plate operable to close electric switch for motor for driving feeding gear which in tum rotates and feeds can to be opened so that the latter is urged into cutting engagement with cutter blade. A spring is provided between cutter blade and actuator to allow same to have limited downward lost motion relative to cutter blade so that manual force on actuator is not required to drive cutter blade into cover of cani. The spring holds cutter blade in engagement with opened can so that cutter blade cooperates with feeding gear to pinch edge of opened can.

11 Claims, 25 Drawing Figures PTNTUECISIS?? 3.706.135

SHEET 1 UF 8 INVENTORY ATTORNEYS Byw/M M/w PATENTED nic 19 |972 SHEET 3 0F 8 PATENTED nic 19 |912 SHEET l# UF 8 PATENIEDUEC 19 |912 3. 706; 135

SHEEI 7 0F 8 INVENTOR ATTORNEY AN ELECTRICALLY POWERED CAN OPENER BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrically poweredcan opener having a cam plate for opening and closing the electrical circuit for an electric motor, a feeding gear driven by the motor,l a cutter blade for cooperating with the feeding gear to hold the peripheral edge of a can to be opened and for cutting the cover thereof, and a push-button type actuation rod for operating the cam plate and the cutter blade.

2. Description of a Prior Art U.S. Pat. No. 3,314,145 discloses a conventional electrically powered can opener of this kind. The can opener disclosed in this patent is designed to be automatically deenergized when a can opening operation is completed. Thev can opener, however, utilizes a manually operated lever to drive the cutter blade into the cover of a can to be opened and dismount or disengage the opened can from the can opener. Specifically, the can to be opened is rotated with its peripheral edge pinched between the feeding gear and the cutter blade. The cutter blade is wedged into the cover of thevcan substantially at the same time'as the start of the rotation of the can. Thus, it is difficult to easily drive the cutter blade into the cover of a can unless the manually operated lever is actuated with a large magnitude of manual force. In addition, when a can opening operation is completed, the cutter blade is stopped with the forward end thereof engaging the inner peripheral edge of the opening thus formed in the cover of the opened can. The dismounting of the opened can is performed by actuating the manually operated lever to move the feeding gear against the friction between the opened can and the cutter blade. Thus, a large magnitude of force is required to manually operate the lever in dismounting an opened can from the can opener.

Moreover, the manually operated lever is pivotally mounted on a supporting shaft and, thus, must be operated through a widened range vand in a complicated manner.

SUMMARY OF THE INVENTION It is a general object of the present invention to provide an improved electrically powered can opener which is free from the difficulties above-discussed.

Specifically, the present invention contemplates an improvement in the cam plate and the arrangement for the operative connection between the cam plate, the cutter blade andthe actuation rod of an electrically powered can opener of the kind above-specified so that the actuation rod can be actuated with a reduced magnitude of force to operate the cutter blade at the beginning of cutting operation at which the cutter blade is wedged into the cover of a can to be opened and at the end of the can opening operation at which the cutter blade is lifted to allow the thus opened can to be dismounted. With the above improvement, it is also intended to automatically stop the operation of the can opener when the cover of a can is completely cut.

According to the present invention, there is provided an electrically powered can opener comprising an electric motor, a feeding gear mounted for rotation about a fixed axis and operatively connected to said motor to rotate and feed a can to be opened, a cutter blade mounted for pivotal movement about the axis of a supporting shaft therefor, said blade being voperable to cooperate with said feeding gear to pinch and hold such can so that said blade cuts the cover thereof, a cam plate mounted for pivotal movement about the axis of a supporting shaft therefor, said cam plate being pivotally successively movable to a firstposition in which the electrical circuit for the motor is closed when said cutter blade is positioned above said cover, to a second position in which said circuit is kept closed from the time said cutter blade is driven into said cover to the time said cutter blade completes its cutting to said first, second and fourth positions and for.

stopping the pivotal movement of said cam plate at said third position, meanl responsive to the pivotal movement of said cam plate for pivotally moving said cutter blade, and common means for actuating both of said cam plate moving means and said cutter blade moving means.

The common means is advantageously of a push-button type actuator. The can opener is designed such that the electrical circuit for the motor is closed when the cutter blade is cooperating with the feeding gear to pinch the peripheral edge of a can to be opened and is positioned above the cover of the can. The can to be opened is power-driven so that the cover of the can is urged into cutting engagement with the cutter blade. This makes it possible to depress the actuator with an extremely reduced magnitude of pressure force. When a can opening operation is completed, moreover, the electrical circuit for the motor is opened to deenergize the motor while the cutter blade is held in engagement with the inner peripheral edge of the opened can so that the latter is prevented from falling down off the cutter blade and the feeding gear.

A clearance or a lost motion is advantageously provided between the actuation means and the cutter blade to prevent the force of the actuation means from being transmitted to the cutter blade when the actuation means is depressed to cause the cam plate to be moved from the third position to the fourth position so that the opened can which is held between the cutter blade and the feeding gear may be dismounted from the can opener. This arrangement assures reduction in the y force required to depress the actuation means when an opened can is dismounted from the can opener because the cutter blade is not lowered into the opened can.

A spring member is conveniently provided not only to resiliently hold the power transmission means on the actuation rod in operative connection with the cutter blade but also to be deformable a distance corresponding to the above-mentioned clearance or lost motion. Namely, as stated in the above, the said clearance is provided to prevent the downward force from being transmitted from the actuation rod to the cutter blade when the cam plate is pivotally moved from the third position to the fourth position so that an opened can may be dismounted from the can opener. If the spring were not provided, the cutter blade would be first lowered into the opened can and then lifted away off the opened can a distance corresponding to the return movement of the actuation rod, with a resultant disadvantage that the opened can will fall down off the can opener. In fact, however, the spring member advantageously takes up, by its resilient deformation, the part of the downward movement of the actuation rod which part correspondsto the said clearance during the movement of the cam plate from the second to the third positions so that the cutter blade is not lowered into the opened can. The spring is also operative to retain the cutter blade in engagement with the peripheral edge of the can so r`that the blade can cooperate with the feeding gear to hold the can on the can opener when the actuation rod is returned to its initial position. In addition, the spring is operative to surely transmit the force from the actuation rod to the cutter blade at the beginning of a can opening operation so that the cutter blade is lowered a limited distance, i.e., to the upper surface of the cover of the can to be opened. Thus, the force required to depress the actuation rod is greatly minimized.

The above and other objects and features of the present invention will be made clear by the following description of a preferred embodiment of the invention with reference to the accompanying drawings.

DESCRIPTION OF DRAWINGS FIG. l is a front elevational view of an embodiment of the electrically powered can opener according to the present invention with some components within the housing being shown by broken lines;

FIG. 2 is a top plan view of the can opener in FIG. l;

FIG. 3 is a vertical sectional view of the can opener;

FIG. 4 is a fragmentary sectional side view taken substantially along line IV-IV in FIG. l and illustrates the arrangement between a cutter blade, a feeding gear and driving connections thereto, respectively;

FIGS. 5A, 5B, and 5C through 8A, 8B and 8C illustrate the cutter blade and a related switching mechanism at each stage of successive operation of the can opener, in which, y

FIGS. 5A, 6A, 7A and 8A illustrate, in fragmentary side elevations, the successive operations of the switching mechanism,

FIGS. SB, 6B, 7B and 8B illustrate, in fragmentary side elevations, the relative positions of the cutter blade with respect to a can being opened at respective stages of operation,

FIGS. 5C, 6C, 7C and 8C illustrate, in fragmentary sectional side elevations, the relative positions of the cutter blade with respect to the can at respective stages shown in FIGS. 5B, 6B, 7B and 8B;

FIG. 9 illustrates in side elevation the switching mechanism which is operating to unlock the cam plate shown in FIG. 8A;

FIG. 10 is a fragmentary sectional view taken along line X in FIG. 8A and illustrating the relationship between an actuation rod and a transmission shaft;

FIG. l1 is a fragmentary sectional view of the cam plate taken along line XI XI in FIG. 8A;

FIG. 12 is a fragmentary sectional view of a part of the switching mechanism taken along line XII XII in FIG. 8A;

Referring to FIGS. l to 4 of thedrawings, the electrically powered can opener of the present invention has a casing comprising a front casing part l and a rear casing part 2 united together by means of fastening screws 3. A framemember 4 is Vsecured to the inner surface of the front casing part l by means of screws 6 threadably engaging with bosses 5 on the inner surface of the casing partl. An electric motor comprising a rotor 7 and a stator 8 is mounted on the frame 4 by means of screws l 10 extending through the stator 8. intobosses 9v on the Y frame member 4. The motor has a rotor shaft l1 extending through the rotor 7 for rotation therewith and having ,one end rotatably received Aby a bearing l2 mounted on the frame member 4 while the other end of the rotor shaft l1 is rotatably supported by a bearing 14 housed in a bearing fitting 13 secured to the stator 8'by means of screws l0.

The rotor shaft ll is formed with a first helical gear l5 on the portion thereof adjacent said one end. A second helical gear 16 of a larger diameter is rotatably mounted on a shaft 18 rigidly mounted on a boss 17 on the frame member 4, said helical gears 15 and 16 being in meshing engagement with each other. A first spur gear 19 is mounted on the shaft 18 for rotation with the second helical gear 16. A second spur gear 20 of a larger diameter is rigidly secured to one end portion of a shaft 22 which rotatably extends through a bearing portion 2l of the frame member 4, said second spur gear 20 being in meshing engagement with the first spur gear 19.

The rotatable shaft 22 has its other end portion projecting outwardly of the front casing part l. A feeding gear 23 is rigidly mounted on the other or outer end of the shaft 22. The feeding gear 23 is driven to rotate in counter-clockwise direction by the motor. Namely, the torque of themotor is transmitted through the first and second helical gears 15 and 16 and the first and second spur gears 19 and 20 then to the feeding gear 23. A cutter blade 24 for opening a cover 26 of a can 25 is rigidly mounted on an outer end of a boss 29 by means of a screw 30. The boss 29 movably extends through a guide slot 28 in the front casing part ll and the frame member 4 and is rigidly connected at its inner end with an end portion of a generally triangular arm 31 which is pivotally mounted at the other end portion on a shaft 27 fixed to the frame 4. The pivotal arm 3l is operatively related to a switching mechanism, which is to be described later, so as to be pivotally moved about the shaft 27 for thereby causing the cutter blade 24 to move downwardly along the guide slot28 into a cover 26 of a can 25 to cut and open the cover along a circle adjacent a sealed peripheral edge 25a of the can. During the cutting or can opening operationof-the blade 24, the can 25 is held such that the sealed peripheral edge 25a of the can is supported by the feeding gear 23 while the latter is operating to rotate the can in counter-clockwise direction. In order that the cutter blade 24 may advantageously perform the cutting operation in the above-stated manner, the cutter blade 24 is laterally offset a distance a from the outer end face of the feeding gear 23, as will be seen in FIG. 4.

A coil spring 32 is provided to extend around the bearing portion 21 so that the spring biases the second spur gear inwardly or rightwardly as viewed in FIG. 3. The distance a between the cutter blade 24 and the feeding gear 23 is adjusted at the time of assembly of the apparatus by interposing a spacer ring 33 between the feeding gear 23 and the bearing portion 2l. For this purpose, the rotatable shaft 22 is dimensioned in length such that a space is left between the second spur gear 20 and the bearing portion 21. The spring 32 is intended to always bias the shaft 2l rightwards so that the feeding gear 23 is held axially spaced accurately the distance a from the cutter blade 24.

At the intermediate portion of the pivotal arm 31 is rigidly mounted a rod-like transmission shaft 34 for transmitting the motion of the switching mechanism to the arm 31.

Referring now to FIGS. 5 through 13, a description will be made with respect to the switching mechanism for the electric motor and with respect to the successive can-opening operation of the cutter blade 24 related to the switching operation of the switching mechanism. The latter includes a push-button 35 mounted on the top of an actuation member 36 in such a manner that the button 35 projects u'pwardly from the top of the rear casing part 2. The actuation member 36 extends slidably through openings 39 formed in the top and bottom walls of a switch cover 38. A compression coil spring 40 is provided to extend around the leg portion 41 of the actuator member 36 so that the. spring always biases the latter upwardly. The actuation member 36 is formed therein with a hole 42 through which the transmission rod 34 of the pivotal arm 3l extends laterally so as to transmit the motion of the actuation member 34 to the pivotal arm 3l and to the cutter blade 24. The hole 42 is sized such that a gap or clearance b is provided between the peripheral edge of the hole and the transmission rod 34 for the reasons which will be discussed later. A leaf spring 43 is rigidly mounted at one end on the actuation member 36. The spring 43 is in pressure contact at the other end portion with the upper surface of the transmission rod 34 so that the latter is urged against the lower edge of the hole 42 to thereby avoid the chatter which would otherwise be caused due to the above-mentioned clearance b.

A projection 44 extends from the actuation member 36 laterally through a vertical slot 45 formed in the side wall of the switch cover 38. A cam plate 46 is pivotally mounted at its lower end on a pin 47 which is secured to the switch cover 38. The cam plate 46 has a hooklike cam projection 48 at which the cam plate 46 is contacted and pressed by the projection-44 when the latter is lowered by the actuation by the actuation member 36 so that the cam plate 46 is rotated in clockwise direction. A tortion spring 49 is provided to extend around the pin 47. The spring 49 has its one end engaged with a punched-out projection 50 on the switch cover 38 and the other en engaged with a projection 5l on the cam plate 46 so that the latter is always urged in counter-clockwise direction by the spring 49. Thus, it will be appreciated that the cam plate 46 is rotated in clockwise direction when actuated by the actuation member 36 and is rotated in the reversed or counter-clockwise direction by the spring 49 when-the force by the actuation member 36 is removed. v

A pair of

contact plates

52 and 53 having

contact points

54a and 54b at their one ends are secured by means of rivets 56 to an insulation plate 55 interposed between the

plates

52 and 53. The insulation plate 55 is secured to the switch cover 38 and a support plate 57 secured to the cover 38. A plate 58 of an electrically insulating material is pivotally mounted on the switch c over 38 and the support plate S7 by means of projections 59 engaged into apertures 60 formed in the cover 38 and the plate 57. The arrangement is such that when the cam plate 46 is actuated to rotate in clockwise direction, the cam plate is brought into pressure contact with the plate 58 so that the latter is also rotated in the same direction to urge the contact plate 52 towards the other contact plate 53 to thereby cause the contact point 54a to bebrought into electrical contact with the contact point 54b, as shown in FIG. 6A and 7A, whereby electrical current is fed through lines 61 and 62 to the motor.

The cam portion 48 of the cam plate 46 has its upper surface 63 inclined forwardly and downwardly to provide a guide surface for the projection 44 on the guide surface 63 is set such that, when the projection 44 has been lowered to the position shown in FIG. 6A along the vertical slot 45 in the switch cover 38, the cam plate 46 has been rotated, by the cam action between the projection 44 and the inclined guide surface 63, to a position in which the cam plate causes the

points

54a and 54b to be contacted with each other for switching on the motor. By that time, the cutter blade 24 is moved to a position in which the blade 24 and the feeding gear 23 cooperate together to pinch the peripheral edge 25a of a can 25 therebetween, as best shown in FIG. 6C.

Under the inclined guide or cam surface 63, the cam plate 46 is formed with a cut-out 64 of a generally hook-like shape. The cut-out 64 is provided for the fol lowing reasons: When the actuation member 36 is further moved from the position shown in FIG. 6A to the position shown in FIG. 7A, the projection 44 is moved downwardly beyond the lower end extremity of the cam surface 63 into contact with a guide surface 65 adjacent the cut-out 64. At this position of the projection 44, the cutter blade 24 is operating to cut a cover 26 of a can 25 as best shown in FIG. 7C. When the cutter blade 24 is in its FIG. 7C position, the projection 44 is held in contact with the guide surface 65, as shown in FIG. 7A, by the frctional force produced between the cutter blade 24 and the cut edges of the can cover 26 and, when the cutting operation of the blade 24 is completed, the frctional force is no more sufficient to hold the cutter blade 24 in engagement with the cut edges of the cover 26 so that the blade 24 is returned or moved to a position shown in FIG. 8A, with a result that the projection 44 is moved upwardly into locking engagement with the hook-like cut-out 64.

The upward movement of the projection 44 allows the cam plate 46 to be rotated in counter-clockwise direction to such an extent that the electrical connec` if f tion between the

contact points

54a and 54b is broken.

Adjacent the locking cut-out 64, the cam plate 46 has an inclined projection 66 formed by punching-out the material of the cam plate. When the projection 44 further moved downwardly by the actuation of the push-button 35 and the actuation member 36 to a position in which the forward end of the projection 44 arrives at an undersurface 66a ofthe inclined projection 66,*the cam. plate 46 is rotated in counter-clockwise direction from the position shown in FIG. 8A to the position shown inv FIG. 9. In this position, if the downward pressure on the push-button 35 and hence the actuation member 36 is removed, the latter is allowed tobe moved upwardly by the action of the spring 40. Atthis time, the upward movement of the actuation member 36causes the projection 44 to urge and move the cam plate 46v in an axial direction of the pin 47 against the spring 49 for the cam plate 46 by the cam action between the forward end of the projection 44 and the undersurface 66a of the inclined projection 66 on the cam plate 46.v For this purpose, the cam plate 46 is mounted on the pin 47 for either sliding movement therealong or oscillatory or rocking movement in axial direction of the pin 47. Alternatively, the projection 44 may be made movable in its axial direction with respect to the inclined projection 66 of the cam plate 46. Thus, the projection 44 is released and unlocked from the locking cut-out 64 so that the projection 44 is returned together with the actuation member 36 to the FIG. 5A position.

Referring now to FIGS. 14A through 15B, a can bearing 67 is mounted on and projects from the front casing part l beneaththe feeding gear 23 for bearing against a barrel portion 68 of a can 25 being opened. The bearing 67 has a generally rectangular configuration which is substantially symmetrical in top plan view with respect to a vertical plane passing through an axis 69 of the feeding gear 23. More particularly, the bearing has a rounded convex left end corner or projection 67a projection outwardly from a generic surface of the bearing 67, and a right end comer or projection 67b substantially similar in shape to the corner 67a but projecting outwardly in the same direction a distance somewhat less than that of the projection 67a. A recess is formed between the left and

right projections

67a and 67b for receiving a part of the peripheral surface of the can barrel 68, as will be seen in FIGS. 14A to 15B. The left projection 67a is adapted to bear against the barrel 68 of a can 25 when its cover 26 is being cut while the other or right projection 67b is designed to bear against the barrel when can opening operation is almost completed.

While reference to FIGS. l to 3, a pair of spaced can holding or pressing rods 70a and 70b are rigidly mounted on and extend laterally outwardly from the front casing part l on opposite sides of the slot 28 between the axes of the feeding gear 23 and the screw 30. The right hand rod 70a is designed to bear against the peripheral edge of a can being opened to hold down the can and prevent same from being lifted up during f opening operation therefor while the left hand rod 70b isadapted to cooperate with the right hand rod 70a to prevent the can from being caused to have reciprocated oscillatory movement which is apt to'be caused for the following reasons: The can is held in engagement with the rod 70a during cutting operation in such a manner that the top cover of the can is somewhat rightwardly upwardly inclined with respect to the horizontal. When the cover is completely cut to open the can, the application of the force from the cutter blade to the can is suddenly discontinued. Thus, the opened can is oscillated by gravity in a vertical plane in clockwise-direction into contact with the other rod 70b and then is oscillated in opposite direction. The oscillation will be repeated for a while until the can is stopped upright.

Now the operation of the apparatus by the cooperation of the cam plate 46, the

electrical contacts

54a and 54b and the cutter blade on the pivotal arm 3l which are actuated by the push-button 35 through the actuation member 36 will be described with reference to FIGS. A through 9. First,lan operatorpositions a can to be opened in such a manner that the edge 25a of the can is engaged with the upper portion of the periphery of the feeding gear 23 and the barrel 68 of the can is held against the can bearing 67.'In the position shown in FIG. 5A, since thep'ush-button 35 is not depressed,rthe actuation member'36 is notv lowered.

- Thus, neither the cam plate 46 nor the pivotal arm 31 is rotated and, thus, the

electrical contacts

54a and 54b are maintained separated apart from one another. The cutter blade 24 is positioned above a cover 26 of the can 25 as shown in FIGS. 5B and 5C.

Then, the push-button 35 is depressed to some extent as shown in FIG. 6A. The actuation member 36 is thus lowered to cause the projection 44 thereon to be brought into pressure contact with the inclined cam surface 63 of the cam portion 48 of the cam plate 46 so that the latter is caused to rotate about the pin 47 vin clockwise direction. The plate 58 is therefore rotated in the same direction to urge the contact plate 52 lso that its contact point 54a is brought into contact with the other contact point 54b whereby electrical current is fed to the motor. The rotor 7 of the motor is thus rotated and the torque thereof is transmitted through the first and second helical gears l5 and 16, the first and second spur gears 19 and 20 and the rotatable shaft 22 to the feeding gear 23. At the same time, on the other hand, since the transmission shaft 34 on the pivotal arm 3l is pinched between the retaining spring 43 and the bottom edge of the hole 42 in the actuation member 36, the shaft 34 is downwardly moved together with the member 36. This downward movement rotates the pivotal arm 3l about the fixed pin 27 to cause the cutter blade 24 to arrive at the position, shown in FIGS. 6B and 6C, in which the forward end of the cutter blade 24 leaves a distance c (FIG. 6B) to the top surface of the cover 26 of the can 25 and in which the edge 25a of the can is pinched between the feeding gear 23 and the cutter blade 24. The can 25 in this position, therefore, is not allowed to fall down off the can opener even if the manually gripping force on the can is released or removed from the can and the latter is rotated about its axis in counter-clockwise direction by the feeding gear 23 rotating in the same direction.

lf the push-button 35 is further depressed to the position shown in FIG. 7A, the actuation member 36 is similarly further moved downwardly to causethe projection 44 thereon to slide over the inclined cam surface 63 and arrive at the guide surface 65 for the locking cut-out 64 in the cam plate 46 so that the cam plate 46 is further rotated in clockwise direction to hold the

contact points

54a and 54b in closed position as shown in FIG. 7A.

At the same time, the pivotal arm 31 is also further rotated in clockwise direction as shown in FIG. 7B so that the cutter blade 24 is driven into the cover 26 of the can 25 and automatically severs the material of the cover 26 by virtue of the counter-clockwise rotation of the can caused by the feeding gear 23. During the can opening operation of the cutter blade 24, it is not required to manually hold down the push-button 35 because the cutter blade 24 is maintained projecting into and engaging with the cut edges in the cover 26 by the friction therebetween.. In other words, not only is it unnecessary to hold down the push-button 35 but also it is not required to manually hold the can during opening operation therefor. The apparatus is operable to automatically perform a can opening operation.

It will be appreciated that, since it is the rotation of actuation push-button 35. This means that a push-button type electric switching mechanism may be employed as the switch for the electrically powered can opener of the present invention.

When the cover 26 of the can has been severed completely, the cutter blade 24 and the switching mechanism will have positions shown in FIGS. 8A and 8C, respectively. Specifically, since no cutting resistance is exerted to the cutter blade 24 any longer, the actuation member 36 is lifted by the action of the compression spring 40. The projection 44 on the actuation member 36 is guided by the locking cut-out 64 to move into contact with the side end face of the inclined projection 66 at the bottom of the cut-out 64 and is locked thereby. This movement of the projection 44 changes the points of contact thereof with the cam plate 46 so that the latter is rotated in counter-clockwise direction by the spring 49, with a result that the pressure force by the cam plate 46 is removed from the plate 58 to allow the contact plate 52 to return to its original position for thereby separating the

contacts

54a and 54b apart from each other.

The transmission rod 34 pinched between the retaining spring 43 and the peripheral edge of the hole 42 in the actuation member 36 is also lifted in a similar manner to the rod 36 so that the free end of the pivotal arm 31 is moved upwardly to lift the cutter blade 24 to the position in which the blade still extends into the cover 26a a distance d, as shown in FIG. 8B. The can 25, therefore, is not allowed to freely fall down because the edge 25a is still pinched by the feeding gear 23 and the cutter blade 24.

Then, the push-button 35 is again depressed downwardly to move the projection 44 of the actuation member 36 within the locking cut-out 64 along and past the side end face of the inclined projection 66 to a position below the bottom end of the projection 66. In this position of the projection 44, the forward end ex tremity thereof is laterally spaced from the bottom end face of the inclined projection 66 and positioned beneath the undersurface thereof. Thus, if the pressure is removed from the push-button 35, the compression spring 40 lifts the actuation member 36 to cause the projection 44 to slide upwardly along the undersurface 66a of the inclined projection 66 to the position shown in FIG. 5A while the cam plate is not rotated in any direction so that the

contacts

54a and 54b are held opened.

The cutter blade 24 is also returned to the position shown in FIGS. 5B and 5C. The opened can is therefore disengaged both from the feeding gear 23 and the cutter blade 24 and, thus, may be dismounted from the apparatus by a single hand. j

In the event that the cutter blade 24 should have been clogged by the edge of the opened can sandwiched between the cutter blade 24 and the feeding gear 23, the switching mechanism can be positively unlocked. The downward movement of the actuation member 36 is not required to further downwardly move the cutter blade 24 from the position shown in FIGS. 8B and 8C. This is because of the reasons that the clearance b is provided between the transmission shaft 34 and the peripheral edge of the hole 42 in the actuation member 36, said distance b being necessary for the projection 44 to be moved a distance along and past the side edge of the inclined projection 66, and that the retaining spring 43 is designed to have a sufficient resiliency for the spring to be resiliently bent or deformed upwardly, as shown in FIG. 9, to take up the part of the downward movement of the actuation member 36 which corresponds to the distance b. It will be therefore appreciated that an extremely smaller magnitude of pressure is sufficient to depress the pushbutton 35 when the depression is to unlock the projection 44 from the cut-out 64 and to return the related components to their initial positions.

Unless the retaining spring 43 is provided, there will be a possibility that, since the clearance b is provided between the transmission rod 34 and the peripheral edge of the hole 42, the cutter 24, when it lhas completed its cutting operation (FIGS 7B and 7C), is upwardly moved a distance which includes the distance b so that the opened can is disengaged from between the cutter blade 24 and the feeding gear 23 and falls down therefrom. In fact, however, the transmission shaft 34 of the pivotal arm 3l is pinched between the retaining spring 43 and the bottom edge of the hole 42 so that the cutter blade 24 is maintained in the position shown in FIGS. 8B and 8C thus to prevent the can from otherwise being disengaged from the apparatus upon completion of the opening operation thereof, with a resultant advantage that the operator is not required to stand aside the apparatus for watching the can opening operation.

As having been described in the above, the switching mechanism of the can opener of the present invention is arranged such that the apparatus is switched on with the cutter blade positioned above a cover 26 of a can 25 leaving a distance c therebetween, as shown in FIG.

6B, and is switched off with the cutter blade projectingA into the cover 26 a distance d, as shown in FIG. 8B so that a larger distance corresponding to the distance c plus the distance d is provided between the positions at which the apparatus is switched on and off, respectively. It will be understood that the apparatus is impractical unless it is switched off with the cutter blade 24 positioned below a position of the blade at which the apparatus is switched on.

Referring now to FIGS. 14, l and l, a description will be made with respect to the can bearing 67 and to the can bearing rods'70a and 70b. When the cover 26 of can 25 is being cut as illustrated in FIGS. 7B and 7C, the cutter blade 24 is positioned in a vertical plane 69 which passes through the axis of the feeding gear 23. In this position of the blade, the central axis of the can 25 is included in the vertical plane andthe barrel 68 of the can 25 bears against the left end projection 67a of the bearing 67, as illustrated in FIG. 14A. When the can is opened, the cutter blade 24 is moved a distance e in counter-clockwise direction to a position illustrated in FIG. 8B. By this movement, the barrel 68 of the can 25 is allowed to have a slight rolling movement -by gravity along the arcuate surface of -the recess between the

projections

67a and 67b into abutment contact with the latter. In this position, the central axis of the cutter blade 24 is coincident with the axis of the can 25, as illustrated in FIG. 15A.'Thus, the relationship between the cutter blade 24 and the can 25 is kept unchanged with the exception that the gap between the cutter blade 24 and the peripheral edge 25a of the can 25 iswidened. This ensures easier and simultaneous returning of the cutter blade 24 and the switching mechanism to their initial positions.

With respect to the can bearing rods 70a and 70b, since the edge 25a of the can 25 receives an upward force which tends to pivot the can 25 in counterclockwise direction about the right hand rod 70a due to the rotation of the feeding gear 23 so that the right side portion of the edge 25a of the can is urged against the rod 70a. When the can is opened, on the other hand, the upward force is no more exerted on the right hand portion of the can 25 and, for this reason, the can is apt to be oscillated in the opposite direction or clockwise direction by the force of gravity of the can and is driven against the other or lefthand rod 70b. The can is again oscillated in counter-clockwise direction byreaction force by the rod 70b into contact with the right hand rod 70a. The oscillation is discontinued after a few reciprocated movements of oscillation.

As described hereinabove, the can opener of the present invention employs a push-button type electric switch which is operatively connected to the cutter blade. This ensures a simplified operation of the apparatus. The push-button type switch utilizes a cam to open and close the electrical contact points. It is, therefore, possible to cause the cutter blade to have stepped motion in downward and/or upward movement thereof. This satisfies the requirements for the operation of the apparatus in that the cutter blade is caused to have their different positions, one being the position in which the cutter blade operates to open the cover of a can, another being the position at which the blade is automatically stopped after completion of the cutting operation and the other being the position to which the blade is returned, so that the cutter blade cooperates with the feeding gear to firmly grip therebetween the peripheral edge of an opened can to'prevent the same from falling down off the can opener when the cutter blade is automatically stopped upon completion of can opening operation. In addition, the cutter blade is returned to its original position by the operation of the switch so that the opened can may be dismounted from the apparatus. This provides an advantage that the can opener of the invention is operable automatically and is entirely free from'a troublesome manual service that an operator is required to stand aside the apparatus during can opening operation so as`to receive an opened can in his hands. l

The push-button type switch which is operatively connected to the cutter blade has its cam which is shaped such that the opener is switchedon and off at different positions of the cutter blade with respect to the cover of a can which is placed in position on the apparatus. Namely, the motor ofk the can fopener is switched on when the forward end of the cutter blade is positioned below the top of the peripheral edge of the can to cooperate with the feeding gear to grip the peripheral edge so that the cutter blade is driven into the cover of the can by the rotation of the can caused by the feeding gear. Thus, a pressure force large enough to depress the push-button of the switch will be sufficient to cause the cutter blade to cut into the material of the cover of a can. Also, when can opening operation is completed, the motor of the can opener is switched off with the forward end of the cutter blade being positioned below the top of the peripheral edge of the opened can so that the blade cooperates with the feeding gear to grip the peripheral edge of the can to prevent the latter from falling down.

Moreover, the push-button switch is held in its on position during a can opening operation by the cutting blade and the material of the cover being cut. The switch is shifted to its off position upon completion of the cutting operation and is held in this position. In this position of the switch, the cutter blade is stopped at a position below the cover to cooperate with the feeding gear to pinch the peripheral edge of the opened can. The push-button switch is depressed so -as to be unlocked so that the cutter blade is returned to its original position. The power transmission means interposed between the cutter blade and the switch is provided with a clearance within which the push-button switch is allowed to have a downward lost motion with respect to the transmission means. This clearance corresponds to the distance through which the push-button switch is moved so as to be unlocked. The lost motion prevents the unlocking movement of the push-button switch from being subjected to a frictional resistance which will otherwise be produced between the cutter blade and the inner peripheral edge of the opened can and, thus, makes it possible to actuate the push-button with an extremely reduced magnitude of pressure force. For this reason, a push-button type switch, which is more conveniently useful as compared with other types of switches, may easily and advantageously be utilized in the can opener to make the same more conveniently operable.

The clearance for the above-mentioned downward lost motion of the push-button switch is advantageously taken up by the retaining spring which is provided to hold down the transmission means. Namely, if the retaining spring were not provided, the cutter blade, upon completion of its cutting operation, will be moved from the cutting position a distance which includes the f distance for the lost motion, with a resultant disadvantage that the cutter is no longer capable of cooperating with the feeding gear to hold the peripheral edge of an opened can therebetween. In fact, however, the spring not only retains the power transmission means but also is resiliently deformed a distance corresponding to the distance of the lost motion to prevent the cutter blade overrunning so that the latter can cooperate with the feeding gear to grip the peripheral edge of an opened can therebetween to prevent the same from falling down of the can opener. Therefore, the clearance for the lost motion achieves its intended purpose.

The peripheral edge of a 'can is pinched between the feeding gear and the cutter blade during and after the can opening operation of the blade. The barrel of the can is urged against one of the projections or end corners of the can bearing during the can opening operation. When the can is opened, the can is rolled by gravity to and held in abutment contact with the other projection of the can bearing, said other projection extending laterally to an extent less than that of said one projection. This movement of the can produces an additional gap between the cutter blade and the inner peripheral edge of the open top of the can to reduce the friction between the cutter blade and the can. Thus, the returning force of a push-button switch itself will be sufficient to also return the cutter blade to its original rest position. In order to provide a conveniently opera ble can opener, therefore, a push-button type switch may be utilized without any improvement in the can opener of the present invention.

What is claimed is:

l. An electrically powered can opener comprising;

an electric motor;

a feeding gear mounted for rotation about a fixed axis and operatively connected to said motor to rotate and feed a can to be opened;

a cutter blade mounted for pivotal movement about the axis of a supporting shaft therefor, said blade being operable to cooperate with said feeding gear to pinch and hold such can so that said blade cuts the cover thereof;

a cam plate mounted for pivotal movement about the axis of a supporting shaft therefor, said cam plate being pivotally successively movable to a first position in which the electrical circuit for said motor is closed when said cutter blade is positioned above said cover, to a second position in which said circuit is kept closed from the time said cutter blade is driven into said cover to the time said cutter blade completes its cutting operation, to a third position in which said circuit is opened to deenergize said motor when said cutter blade has completed its cutting operation and is cooperating with said feeding gear to hold said can, and to a fourth position in which said cam plate is prepared to be pivotally moved when said cutter blade has caused said can to be disengaged from said cutter blade and said feeding gear;

means for pivotally moving said cam platelto said first, second and fourth positions and for stopping the pivotal movement of said cam plate at said third position;

esoY

means responsive to the pivotal movement of said cam plate for pivotally moving said cutter blade; and

common means for actuating both of said cam plate moving means and said cutter blade moving means.

2. An electrically powered can opener comprising;

an electric motor;

a feeding gear rotatably mounted on a base and operatively connected to said motor to rotate and feed a can to be opened;

a cutter blade rigidly secured to a mounting portion of an 'arm pivotally movable about the axis of a supporting shaft onsaid base, said mounting portion extending through an arcuate slot formed in said base, said cutter blade being operable to cooperate with said feeding gear to pinch and hold such can so that said blade cuts the cover thereof;

a stop for stopping the pivotal movement of said cam plate at said fourth position;

common means for actuating both of said cam plate moving means and said cutter blade moving means, said common means being biased in a direction opposite to the direction for said actuation.

3. An electrically powered can opener as claimed in claim l, in which said cam plate includes a first inclined portion against which said means for pivotally moving said cam plate is urged to move the same to said first position, a locking portion with which means for pivotally moving said cam plate is engaged to hold the same in said third position, a guide portion for positioning said cam plate in said second position and guiding said means for pivotally moving said cam plate to said locking portion after said cutter blade has cut the cover of a can, and a second inclined portion operable to unlock said means for pivotally moving said cam plate to position said cam plate in said fourth position and to return the thus unlocked cam plate moving means to a position in which said cam plate is prepared to be pivotally moved.

4. An electrically powered can opener as claimed in claim 3, in which said cam plate is always actuated by a spring in a direction opposite to the direction in which said cam plate is moved to close said electrical circuit,

said cam plate being also slidably movable in the axial direction of said supporting shaft on which said cam plate is pivotally mounted.

5. An electrically powered can opener as claimed in claim 3, in which said cam plate is always actuated by a spring in a direction opposite to the direction in which said cam plate is moved to close said electrical circuit, said cam plate being also oscillatable in the axial direction of said supporting shaft on which said cam plate is pivotally mounted.

6. An electrically powered can opener as claimed in claim 3, in which said cam plate is always actuated by a spring in a directionopposite to the direction in which said cam plate is moved to close said electrical circuit, said means for pivotally moving said cam plate being movable with respect to said second inclined portion in a direction substantially prependicular to the plane in which said cam plate is pivotally movable.

7. An electrically powered can opener as claimed in claim l, in which a clearance is provided between said means for pivotally moving cutter blade and said cornmon means so that said means for pivotally moving said cam plate is movable a distance to unlock said cam plate in said third position and so that said cutter blade is not actuated to move during the movement of said cam plate moving means through said distance.

8. An electrically powered can opener as claimed in claim 7, in which said clearance is formed by a hole in said common means and said means for pivotally moving'said cutter blade, the last-mentioned means comprising a pin member projecting from a pivotable arm and extending loosely into said hole, said cutter blade being rigidly secured to said pivotable arm.

9. An electrically poweredcan opener as claimed in claim 6, in which said clearance is formed by a hole in said common means and means for pivotally moving said cutter blade, the last-mentioned means comprising a pin member projecting from a pivotable arm and extending loosely into said hold, said cutter blade being rigidly secured to said pivotable arm, said pin member being biased by a spring means in a direction opposite to that in which said cutter blade is returned to its initial position, said spring means being deformed when said means for pivotally moving said cam plate is moved so as to be unlocked from said cam plate which is positioned in said third position.

l0. An electrically powered can opener as claimed in claim l, in which said cutter blade hasa generally triangular forward end to wedge samevinto a cover of a can to be opened.

l1. An electrically powered can opener as claimed in claim l, in which first and second projections are provided below and adjacent said feeding gear for bearing against the barrel of a can being opened, said first bearing projection being adapted to bear against said barrel while said cutter blade operates to cut the cover of said can, said can after being opened being moved to an urged against said second bearing projection so that the latter bears against said opened can, said second projection extending a distance less than that of said first projection.

Claims

1. An electrically powered can opener comprising; an electric motor; a feeding gear mounted for rotation about a fixed axis and operatively connected to said motor to rotate and feed a can to be opened; a cutter blade mounted for pivotal movement about the axis of a supporting shaft therefor, said blade being operable to cooperate with said feeding gear to pinch and hold such can so that said blade cuts the cover thereof; a cam plate mounted for pivotal movement about the axis of a supporting shaft therefor, said cam plate being pivotally successively movable to a first position in which the electrical circuit for said motor is closed when said cutter blade is positioned above said cover, to a second position in which said circuit is kept closed from the time said cutter blade is driven into said cover to the time said cutter blade completes its cutting operation, to a third position in which said circuit is opened to deenergize said motor when said cutter blade has completed its cutting operation and is cooperating with said feeding gear to hold said can, and to a fourth position in which said cam plate is prepared to be pivotally moved when said cutter blade has caused said can to be disengaged from said cutter blade and said feeding gear; means for pivotally moving said cam plate to said first, second and fourth positions and for stopping the pivotal movement of said cam plate at said third position; means responsive to the pivotal movement of said cam plate for pivotally moving said cutter blade; and common means for actuating both of said cam plate moving means and said cutter blade moving means.

2. An electrically powered can opener comprising; an electric motor; a feeding gear rotatably mounted on a base and operatively connected to said motor to rotate and feed a can to be opened; a cutter blade rigidly secured to a mounting portion of an arm pivotally movable about the axis of a supporting shaft on said base, said mounting portion extending through an arcuate slot formed in said base, said cutter blade being operable to cooperate with said feeding gear to pinch and hold such can so that said blade cuts the cover thereof; a cam plate mounted for pivotal movement about the axis of a supporting shaft therefor, said cam plate being pivotally successively movable to a first position in which the electrical circuit for said motor is closed when said cutter blade is positioned above said cover, to a second position in which said circuit is kept closed from the time said cutter blade is driven into said cover to the time said cutter blade completes its cutting operation, to a third position in which said circuit is opened to deenergize said motor when said cutter blade has completed its cutting operation and is cooperating with said feeding gear to hold said can, and to a fourth position in which said cam plate is prepared to be pivotally moved when said cutter blade has caused said can to be disengaged from said cutter blade and said feeding gear; a stop for stopping the pivotal movement of said cam plate at said fourth position; means responsive to the pivotal movement of said cam plate for pivotally moving said cutter blade; and common means for actuating both of said cam plate moving means and said cutter blade moving means, said common means being biased in a direction opposite to the direction for said actuation.

3. An electrically powered can opener as claimed in claim 1, in which said cam plate includes a first inclined portion against which said means for pivotally moving said cam plate is urged to move the same to said first position, a locking portion with which means for pivotally moving said cam plate is engaged to hold the same in said third position, a guide portion for positioning said cam plate in said second position and guiding said means for pivotally moving said cam plate to Said locking portion after said cutter blade has cut the cover of a can, and a second inclined portion operable to unlock said means for pivotally moving said cam plate to position said cam plate in said fourth position and to return the thus unlocked cam plate moving means to a position in which said cam plate is prepared to be pivotally moved.

4. An electrically powered can opener as claimed in claim 3, in which said cam plate is always actuated by a spring in a direction opposite to the direction in which said cam plate is moved to close said electrical circuit, said cam plate being also slidably movable in the axial direction of said supporting shaft on which said cam plate is pivotally mounted.

6. An electrically powered can opener as claimed in claim 3, in which said cam plate is always actuated by a spring in a direction opposite to the direction in which said cam plate is moved to close said electrical circuit, said means for pivotally moving said cam plate being movable with respect to said second inclined portion in a direction substantially prependicular to the plane in which said cam plate is pivotally movable.

7. An electrically powered can opener as claimed in claim 1, in which a clearance is provided between said means for pivotally moving cutter blade and said common means so that said means for pivotally moving said cam plate is movable a distance to unlock said cam plate in said third position and so that said cutter blade is not actuated to move during the movement of said cam plate moving means through said distance.

8. An electrically powered can opener as claimed in claim 7, in which said clearance is formed by a hole in said common means and said means for pivotally moving said cutter blade, the last-mentioned means comprising a pin member projecting from a pivotable arm and extending loosely into said hole, said cutter blade being rigidly secured to said pivotable arm.

9. An electrically powered can opener as claimed in claim 6, in which said clearance is formed by a hole in said common means and means for pivotally moving said cutter blade, the last-mentioned means comprising a pin member projecting from a pivotable arm and extending loosely into said hold, said cutter blade being rigidly secured to said pivotable arm, said pin member being biased by a spring means in a direction opposite to that in which said cutter blade is returned to its initial position, said spring means being deformed when said means for pivotally moving said cam plate is moved so as to be unlocked from said cam plate which is positioned in said third position.

10. An electrically powered can opener as claimed in claim 1, in which said cutter blade has a generally triangular forward end to wedge same into a cover of a can to be opened.

11. An electrically powered can opener as claimed in claim 1, in which first and second projections are provided below and adjacent said feeding gear for bearing against the barrel of a can being opened, said first bearing projection being adapted to bear against said barrel while said cutter blade operates to cut the cover of said can, said can after being opened being moved to an urged against said second bearing projection so that the latter bears against said opened can, said second projection extending a distance less than that of said first projection.