WO2020142756A1 - Manual can opener with overdrive - Google Patents

Abstract

Disclosed is an apparatus for opening cans which includes first and second handles, a crank having a grip and a toothed, internal recess comprising a driving gear, and a first driven gear housed within and engaged with the driving gear. The first driven gear is connected to the first handle by an axle oriented orthogonally to the teeth of the driving gear and coupled to a second driven gear on the same axle but on the opposite side of the first handle relative to the crank and first driven gear. The second driven gear is coupled to a first cutting piece configured to contact a can and exert torque on the can when the second and a third driven gear are engaged and the crank is turned. The third driven gear is configured to become engaged with the second driven gear and is coupled to a second cutting piece by a second axle running through the second handle. The first cutting piece comprises one of a traction wheel and a cutting wheel, and the second cutting piece comprises the other.

Description

Manual Can Opener with Overdrive

Priority Claim

This application claims the benefit of U.S. Provisional Patent Application No. 62/917,846 filed January 5, 2019.

Field

The present disclosure relates generally to apparatus and methods for opening canned food and other types of cans, as well as applications improving rotational and cutting speed and power delivery through hand cranks, rotational drives, and gears for improved gearing and leverage/power delivery.

Background

Most can openers consist of two handles connected to two primary plates, on one of which plates is mounted a crank that rotates a driving gear. Driving gears are generally mounted on an axle or shaft on which is mounted a second gear (first driven gear) that drives a third gear (second driven gear) mounted on the second plate. This third gear is fixed on an axle with a cutting wheel such that, when the driving gear drives the two driven gears, the cutting wheel spins with them and cuts into the can along its outer perimeter. The two plates are generally connected at a pivot point either in front of or behind the gearing and cutting apparatus relative to the handles, forming either a“V” shape or an“X” shape, respectively. The driving gear is generally of a size similar to that of the cutting wheel (and driven gears). Some can openers use drive wheels of slightly larger size than their cutting wheels, though traditional can openers having larger drive gears tends to cause the can opener to more easily detach from the lip of the can during operation.

Summary

This disclosure relates to an improved can opening device. The device is useful for opening canned food and other types of cans, as well as applications improving rotational speed and power delivery through hand cranks, rotational drives, and gears for improved gearing and leverage/power delivery.

Disclosed is an apparatus for opening cans which includes first and second handles having distal and proximal end portions, a crank having a grip and a toothed, internal recess comprising a driving gear, and a first driven gear housed within and engaged with the driving gear. The first driven gear is connected to the proximal end of the first handle by a first axle oriented orthogonally to the teeth of the driving gear and coupled to a second driven gear on the same axle but on the opposite side of the first handle relative to the crank and first driven gear. The second driven gear is coupled to a first cutting piece configured to contact a can and exert torque on the can when the second and a third driven gear are engaged and the crank is turned. The third driven gear is configured to become engaged with the second driven gear and is coupled to a second cutting piece by a second axle running through the second handle. The first cutting piece comprises one of a traction wheel and a cutting wheel, and the second cutting piece comprises the other of a traction wheel and a cutting wheel.

Also disclosed is a method of opening a can comprising obtaining a can having a lid and obtaining an apparatus for opening cans, the apparatus for opening cans comprising first and second handles having proximal and distal end portions, a crank having a grip and a toothed, internal recess comprising a driving gear, and a first driven gear housed within and engaged with the driving gear. The first driven gear is connected to the proximal end of the first handle by a first axle oriented orthogonally to the teeth of the driving gear and coupled to a second driven gear on the same axle but on the opposite side of the first handle relative to the crank and first driven gear. The second driven gear is coupled to a first cutting piece configured to contact a can and exert torque on the can when the second and a third driven gear are engaged and the crank is turned. The third driven gear is configured to become engaged with the second driven gear and is coupled to a second cutting piece by a second axle running through the second handle. The first cutting piece comprises one of a traction wheel and a cutting wheel, and the second cutting piece comprises the other of a traction wheel and a cutting wheel. The method further comprises positioning the apparatus such that the traction wheel and the cutting wheel surround the lip of the can having a lid; squeezing the distal ends of the first and second handles together such that the circular blade cuts into the lip of the can having a lid; and turning the crank in a forward (driving) direction such that the driving gear drives the driven gears, turning the cutting wheel and cutting the lid of the can.

Also disclosed is a method of opening a can comprising obtaining an apparatus comprising: a first handle having a proximal end portion and a distal end portion; a second handle having a proximal end portion and a distal end portion; a crank having a grip and a toothed, internal recess comprising a driving gear; a driven gear housed within and engaged with the driving gear; and first and second cutting pieces configured to surround the lip of a can having a lid. The first cutting piece comprises one of a traction wheel and a cutting wheel, and the second cutting piece comprises the other of a traction wheel and a cutting wheel. The method further comprises positioning the apparatus such that the traction wheel and the cutting wheel surround the lip of a can having a lid; squeezing the distal ends of the first and second handles together such that the circular blade cuts into the lip of the can having a lid; and turning the crank in a forward (driving) direction such that the driving gear drives the driven gears, turning the cutting wheel and cutting the lid of the can.

Another embodiment described herein is an apparatus for opening cans, comprising a first handle having a proximal end portion and a distal end portion, the proximal end portion being connected to a first plate; a second handle having a proximal end portion and a distal end portion, the proximal end portion being connected to a second plate; a crank having a grip and being connected to a driving gear, the crank comprising a ratcheting mechanism having an unlimited range of motion with respect to rotation of the crank; and a first driven gear engaged with a non-coaxial driving gear to provide overdrive, the first driven gear being adjacent to, or within, the driving gear. The first driven gear is connected to the proximal end of the first handle by a first axle oriented orthogonally to the teeth of the driving gear and coupled to a second driven gear on the same axle but on the opposite side of the first plate relative to the crank, ratcheting mechanism and first driven gear.

Brief Description of the Drawings

Preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings. The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is an embodiment of a can opener in accordance with the present invention;

FIG. 2 is top perspective view of the can opener of FIG. 1;

FIG. 3 is an enlarged and cutaway portion of an exemplary ratchet assembly of the can opener of FIG. 1 ;

FIG. 4 is an alternative perspective view of the ratchet assembly of FIG. 3;

FIG. 5 is an embodiment of a can opener in accordance with the present invention, wherein the handles are offset from the plane formed by the plates;

FIG. 6 is an alternative view of the can opener of FIG. 5 but having a bent grip at the end of the crank;

FIG. 7 is an enlarged and cutaway portion of the gear assembly of the can opener of

FIG. 1;

FIG. 8 is a support member for the gear assembly of the can opener of FIG. 1;

FIG. 9 is a cross-section of a portion of the gear assembly of FIG. 1, including the support member of FIG. 8;

FIG. 10 is an alternative embodiment of the support member of FIG. 8;

FIG. 11 shows the support member of Fig. 10 when initially cut from a flat sheet, before bending.

FIG. 12 is a cutaway portion of an alternative crank of the can opener of FIG. 1; FIG. 13 is an enlarged and cutaway portion of the ratchet assembly of the can opener of FIG. 1;

FIG. 14 is an alternative perspective view of the ratchet assembly of FIG. 13;

FIG. 15 is a portion of an alternative ratchet assembly of the can opener of FIG. 1; and

FIG. 16 is a portion of an alternative ratchet assembly of the can opener of FIG. 1;

Detailed Description

Shown in Figures 1-4 is a can opener 100 as an exemplary embodiment. The can opener 100 comprises a pair of handles, namely a first handle 110 and a second handle 115, having first and second proximal end portions, 111 and 116, respectively, first and second distal end portions, 112 and 117, respectively and a first crank 130 having a toothed internal recess 132 comprising a driving gear 131. Connected to the proximal end portion 111 of the first handle 110 is a first plate 121 through which runs the first axle 123. Connected to the proximal end portion 116 of the second handle 115 is a second plate 122 through which runs the second axle 124. The two plates 121 and 122 are held together at a pivot point 120 about which the first and second handles 110 and 115 may be rotated relative to each other. In embodiments, the driving gear 131 is integral with the first crank 130. In embodiments, the driving gear is disposed on the crank side of the plates 121, 122.

The handles 110 and 115 may lie in the same planes as the two plates 121 and 122, as shown in Figure 1. Alternatively, the handles 110 and 115 may extend from the plane formed between the two plates 121 and 122 in a direction diagonal relative to that plane and away from the crank as shown in Figures 5 and 6. In such an embodiment, the handles are ideally offset from the plane formed by the plates by an angle Q of about ten to about thirty degrees, or about fifteen to about 25 degrees, though smaller or larger angles of deviation are possible.

As shown in Figures 1 and 7, a first driven gear 141 is housed within the recess 132 and engaged with the driving gear 131, the driven gear 141 being affixed around an axle 123 running orthogonally through the plate 121 (not shown in Figure 7) attached to the proximal end portion 111 of the first handle 110. A second driven gear 142 is coupled to the first driven gear 141 on the same axle 123 but on the opposite side of the plate 121 and is coupled to a traction wheel 143 on the furthest end of the same axle 123 from the first crank 130. A third driven gear 144 is configured to become engaged with the second driven gear 142 when the distal end portions 112, 117 of the two handles, 110 and 115, are brought together. A circular blade 145 is coupled to the third driven gear 144 by a second axle 124, the second axle 124 running orthogonally through a second plate 122 (not shown in Figure 7) connected to the proximal end 116 of the second handle 115.

In the embodiment shown in Figures 8 and 9, a support member 170 is fitted between the toothed, internal recess 132 comprising the driving gear 131 and the first driven gear 141. Figure 8 shows the support member 170 having two bores 171 by which to fix the support member 170 to the plate 122 and a bore 172 by which to fix the first crank 130 to the support member 170 through the ratchet assembly 150 (described below). The support member 170 allows for spacing the mounting point for the crank further away from the plate 122. This is useful in cases where the toothed, internal recess comprising the driving gear 131 is less than two times larger than the first driven gear 141 as it allows the first driven gear 141 to overlap a line passing through the center of the bore 172 without impeding rotation of either gear. If the support member 170 were not present in this case, an axle through the first crank 130 would intersect with the footprint of the first driven gear 141.

An alternative support member 180 is shown in Figures 10 and 11. This alternative support member 180 functions similarly to support member 170 and includes a bore 182, but can be formed flat as in Figure 11 and has three arms 181 which may each be bent ninety degrees and inserted into corresponding slots or holes on the plate 122

The first crank 130 may be comprised of a simple grip 160 as shown in the can opener of Figure 2. The operator may desire to use the first crank 130 as a simple grip 160 if, for example, the operator preferred to increase ratcheting speed over maximizing power. Further, the end of the crank might be angled or offset toward the plates 121, 122 at its distal end, as the crank 240 of the can opener 200 shown in Figure 6 so it may be gripped fully by the thumb and fingers, thus enabling the operator to maintain a comfortable finger, hand, and wrist position during ratcheting and full rotational drive. As an alternative to the first crank 130, rotatable knob 164 on the end of a second crank 162, shown in Figure 12, allows comfort and a more natural (and thus stronger) hand and wrist position throughout the range of motion; for example, when ratcheting, it allows for more force delivery throughout the range of the stroke. It generally also can permit a greater range of motion than would a simple, fixed grip 160 where the hand and wrist position is fixed relative to the crank. For example, a more round or larger radius fixed grip 160 might provide similar leverage but rely on more wrist and hand rotation, and would also be less conducive to use with shorter height cans, where such a crank may interfere with the surface on which the can rests.

In some embodiments, the second crank 162 may be used in place of the first crank 130. The second crank 162 is comprised of an arm 163 and a knob 164, where the knob is pivotally connected to the arm such that it may rotate freely. In some embodiments, the arm is approximately three inches in length. This design provides significantly greater leverage than most can openers permit in practice; can openers commonly employ levers of length around three inches, but which are connected at their middles, creating in practice a one-and- a-half inch radius about which the crank may spin, substantially reducing the working or effective length and therefore the required torque. Further, standard cranks typically require finger and wrist strength to drive the gears during operation; a longer crank arm plus addition of a rotatable knob provides a significantly more comfortable grip and hand/wrist position over the range of rotation, as it does not require wrist and hand rotation in order to operate, instead relying on larger muscle groups for operation and power generation. Engagement of larger muscles naturally aids in the ability to comfortably provide more force.

In another embodiment not shown the crank may be offset such that it lies in the plane created by the two handles. Such an embodiment may include an interlocking handles that are held together when engaged. Thus, when combined with an offset crank being shaped and set such that the distal end can be gripped by fingertips when also holding onto the handles, and operating in plane with the locked-together handles, the device can be operated with on hand by squeezing the crank so that it rotates against the handles. Such an embodiment would also include a reset spring to enable the crank to rotate in reverse away from the handles after each partial rotation forward drive or cutting stroke of the crank. Such an embodiment would operate more naturally and effectively with overdrive, such that the device could open a can with fewer such drive strokes implemented by each drive or power stroke from squeezing or drawing the crank against the handles. A torsion device would rotate the crank away from the two handles to an open position when at rest. When force is applied against the torsion device such that the crank is rotated towards the two handles, the ratcheting mechanism is engaged and driven in its forward direction such as to operate the device. When force on the torsion device is reduced (i.e. when one releases the crank and handles after squeezing them together), the ratcheting mechanism is driven in its reverse direction such that the driving gear does not operate. In such an embodiment, the handles and the crank may be shaped such they nest or partially inset within the handles and curved at its distal end to allow for a few degrees’ extra range of motion.

Alternatively, interlocking of the two handles (without necessarily locking to hold the handles engaged and in place such that they would not separate until released) might also be incorporated in other embodiments (i.e., those generally intended to be operated with two hands) in order to reduce twisting of the plates and handles relative to one another caused by the higher forces associated with a longer crank arm, driven with the greater force allowed by the crank and overall configuration of the body, arms and hands during operation that can deliver substantially greater forces and the driven gears, increasing the speed of cutting, and, thus, the greater torqueing forces resulting from cranking that would otherwise tend to cause the plates and handles to flex and thus to potentially separate or alter the alignment of the plates and other drive and cutting components located on the cutting side of the plates, including the drive gear remaining tightly engaged relative to the cutting wheel needed to keep the device secure holding the edge of the can during operation.

Further, such embodiments might also include an offset crank (though to a lesser degree than what would be utilized for one-handed operation) such that at the distal end it operates more closely to the plates and handles but without contacting the handles anywhere in its rotation. In this and other embodiments, the crank also may be curved at its distal end to allow for a few degrees’ extra range of motion

As shown in Figure 4, a ratchet assembly 150 is fitted between the first crank 130 and the toothed, internal recess comprising the driving gear 131. In the embodiment shown in Figures 3, 4, 13, and 14, the ratchet assembly 150 comprises a central ring 152 (attached to the ratchet assembly and rotating with the crank at all times and directions) having multiple pawls 153 with ends 154 in contact with asymmetrical grooves or gears 151 etched or formed into the back side of the driving gear 131 such that the ratcheting teeth engage and drive the assembly without slipping off the grooves or gears. Each end 154 of a pawl 153 has multiple teeth 155 (in this embodiment, two teeth), each of which teeth 155 contacts one of the asymmetrical grooves 151. Having multiple teeth 155 on the end 154 of each pawl 153 allows for greater traction between the central ring 152 and the driving gear 131. The central ring 152 is fixed such as to rotate with the crank 130. When the crank 130 is rotated in the forward (driving) direction, the ends 154 of the pawls 153 will engage with some of the grooves or gears 151 (which face inward towards the central ring and its teeth) etched or formed into a 360 degree wall the back side of the driving gear 131 such that rotation of the crank 130 causes corresponding rotation of the ratchet assembly 150 and thus the driving gear 131. When the crank 130 is rotated in the reverse (non-driving) direction, the ends 154 of the pawls 153 will flex (as will each pawl or arm) and ride past the grooves or gears 151 without turning the ratchet assembly 150 or the driving gear 131. Figure 13 demonstrates the relative positions in this embodiment of the central ring 152, pawls 153 and their ends 154, grooves 151, crank 130, and toothed, internal recess comprising the driving gear 131. Figure 14 demonstrates a rotated view of Figure 13.

The driving gear 131 and the first and second driven gears 141 and 142 comprise a reducing gear system such that the crank 130 is overdriven with respect to the ratchet mechanism 150, meaning that one turn of the crank 130 corresponds to several turns of the ratchet mechanism 150. In a preferred embodiment, the ratio of the internal diameter of the driving gear 131 to the external diameter of the first driven gear 141 is at least 1.2: 1 such that one turn of the crank 130 corresponds to 1.2 turns of the ratchet mechanism 150. This ratio is usually in the range of 1.3 : 1 to 3 : 1 [

The ratcheting elements of the design in embodiments provide the ability to both fully and continuously rotate the crank 130 during operation as well as ratcheting within a variable range determined by the operator and/or application (e.g. for short cans being opened on flat surfaces, the exemplary crank is longer than the can height and thus would contact the surface unless ratcheted to utilize only a portion of the rotational range). In the embodiments described herein, the ratcheting grooves and the spaces between them can be smaller than the teeth of the driving gear 131, thus making for less resistance when ratcheting backwards to reset the crank, and also less slack before the gears reengage and power the driven gears 141, 142, and 144. Further, in the embodiments described herein, locating the ratcheting grooves at the largest possible radial distance from the center of the driving gear 131 enables the optimal combination of finest increments and larger grooves for the pawl to engage without skipping or slipping, making them less prone to wear and failure over time than especially if, for example, the grooves or gears were smaller. Additionally, placing the grooves and teeth of the driving gear 131 on two separate planes allows the largest radius for both the driving gears and ratcheting grooves, also thus allowing thinnest driving gear 131 (as opposed to if, for example, both the grooves and the teeth of the driving gear 131 were oriented in the same plane and were concentric). Also, by locating the teeth of the driving gear 131 on the outermost portion of the internal recess, one may fit a greater number of teeth, greater torque is imparted and thus there is less force and wear on each tooth and groove in the ratcheting mechanisms, including the drive gears and other components.

In another embodiment shown in Figure 15, the ratchet assembly 150 comprises a leaf spring assembly 310. This leaf spring assembly 310 is comprised of asymmetrical grooves 311 etched or formed into the back side of the driving gear 131 and a pawl 312 configured to engage the grooves. The pawl has a first end 313 engaged with the grooves and a second end 314 that is affixed to the crank 130 such that the pawl 312 rotates with the crank 130. When the crank 130 is rotated in the forward (driving) direction, the first end of the pawl 313 will engage with one of the grooves 311 such that rotation of the crank 130 causes corresponding rotation of the ratchet assembly 150 and thus the driving gear 131. When the crank 130 is rotated in the reverse (non-driving) direction, the first end of the pawl 313 will return ride past the grooves without turning the ratchet assembly 150 or driving gear 131.

The pawl may be flat as shown in Figure 15, but also might be U-shaped or V-shaped to be more easily inserted into the ratchet assembly 150 and possibly to engage two grooves at once, giving greater hold and reliability. Multiple pawls may also be used to engage multiple grooves at once, providing even greater hold and reliability.

In an alternative embodiment (not shown), the ratcheting grooves are on the outside edge of the driving gear 131 housing, and thus on the surface opposite the teeth of the driving gear 131. Such an embodiment typically requires that a portion of the crank base overlap the driving gear 131 assembly, and likewise might utilize one or more pawls to engage the grooves.

Figure 16 displays an embodiment wherein the ratchet assembly 150 comprises a sprag gear assembly 320. Such assembly (other than the sprags or sprag ring) might be formed or molded as part of the crank, to form a crank and ratcheting assembly. The sprag gear assembly 320 is comprised of roughly asymmetrical figure-eight-shaped sprags 321. These sprags 321 may be molded such that are connected to by a thin membrane to form a single ring connecting all the individual sprags (the thin ring, the sprags and the ring thus comprising a single manufactured piece or part is not shown, but is only necessary and helpful during manufacturing and installation, as a single part) and is configured to rotate with the crank 130 by engaging against a wall 322 or cavities to hold each sprag and only allow for limited motion needed for operation of the sprags (as thy rotate slightly roughly near their center point as they engage and disengage) and either slip past the driving gear 131 during reverse rotation of the crank or engage and lock against a wall or cavity formed into the back side of the internal gear to drive it. When the crank 130 is rotated in the forward (driving) direction, the sprags 321 become locked with respect to the driving gear 131 and exert torque on the driving gear 131, causing it to rotate with the crank 130. When the crank

130 is rotated in the reverse (non-driving) direction, the sprags 321 slip past the driving gear

131 without exerting meaningful torque that might rotate the drive gear assembly in reverse.

The ring of sprags may be molded, e.g. via injection molding, out of thermoplastic or thermoset plastics, or of a composite material. This allows for easy construction as the ring of sprags may simply be placed inside the crank 130. Such a sprag assembly is preferred for this application as it can be accomplished in fewer parts, in plastic, and thus at a lower cost, yet still providing a reliable one-way drive with very low or little slack drive. It is generally advantageous to use a ring of sprags comprised of at least two or more sprags or sprag gars to balance opposing forces.

In an exemplary embodiment, the sprag ratchet drive would comprise of sprags placed in cavities formed between the overlapping space of crank-ratchet assembly and a 360 wall formed on the back side of the internal gear. Both the crank assembly and internal gear housing would have substantially similar outer diameters where they meet or overlap. In such an embodiment the wall on the internal gear back side, alone or together with the crank and ratcheting assembly would form cavities or shapes to locate, contain or constrain the range of motion of the sprags, which when rotated (generally clockwise) slightly during the crank drive or cutting cycle, would tilt or rotate, causing the outer surface of the individual press harder and lock against such wall on the back side of the internal gear, further causing the internal gear to rotate with the crank.

Not shown are other embodiments utilizing larger sprag gears than would fit in the smaller space between the outer wall of the internal gear and the outer wall of the crank assembly circumference. This can be accomplished in a number of ways, including the addition, for example, of a circular ridge of a significantly smaller radius than the outer perimeter that formed onto either the internal gear or crank assembly outer walls where they meet and partially overlap, thus providing a larger space or cavity into which larger sprag gears can be housed. Such larger sprag gears tend to be simpler to manufacture with more reliable operation. Also, as disclosed, when constructed as one molded part in plastic, the sprag gears could be connected to a ring, with shapes in the ring that would provide natural tension on the individual gears when installed in the assembled cavity or space between the internal gar and crank assemblies. Such tension reduces or nearly eliminates slack drive in the sprag gears during operation and driving the crank.

In operation of an embodiment shown in the Figures, the user grasps the handles 110 and 115 and positions the apparatus such that the traction wheel 143 and the circular blade 145 surround the lip of a can. The user squeezes the distal end portions 112 and 117 of the handles 110 and 115 together such that the circular blade 145 cuts into the lid of the can. When the crank 130 is then driven in the forward (driving) direction, the driven gears 141, 142, and 144 cause the traction wheel 143 and the circular blade 145 to turn, causing the can to turn as the circular blade 145 cuts along the top edge of the can. When the crank 130 is driven in the reverse (non-driving) direction, the ratcheting mechanism prevents the driven gears 141, 142, and 144 from being driven. The user may therefore keep one hand on the two handles 110 and 115 and the other hand on the crank 130, rotating the crank back and forth in order to spin and cut the lid of the can without releasing the apparatus.

In operation of another embodiment not shown, the user grasps the handles and positions the apparatus such that the traction wheel and circular blade surround the lip of a can. The user squeezes the distal ends of the handles together and engages the latching mechanism, thereby latching the two handles and together while simultaneously causing the circular blade to cut into the lid of the can. When the user then positions their hand around the handles and the crank, squeezing them together such as to apply force against the torsion device, the driving gear drives the driven gears, causing the traction wheel and the circular blade to turn, thus causing the can to turn as the circular blade cuts along the top edge of the can. When the user relaxes their grip and allows the torsion device to separate the crank from the two handles, the ratcheting mechanism prevents the driving gear from functioning. The user may therefore repeatedly squeeze and release the crank relative to the two handles, driving the ratcheting mechanism in the forward (driving) direction when they are squeezed together, and driving the ratcheting mechanism in the reverse (non-driving) direction when the torsion device separates them.

The embodiments described herein contain numerous improvements over can openers in the prior art. For example, an object of the disclosed embodiments is to provide potentially unlimited ratcheting capability in conjunction with overdrive capability. In an exemplary embodiment, the device would be designed to both improve gearing such that it is in the range of about 1.2: 1 to about 4: 1, or about 1.3: 1 to about 3: 1, or about 1.4: 1 to about 2: 1, while increasing leverage and means for the operator to ergonomically and more easily apply greater force to compensate for some of the greater power needed to rotate the crank (or knob), gears, and ultimately the cutting wheel more rapidly with comfortably applied hand, wrist, and arm force. For example, to rotate the crank or knob at a given speed, the greater power requirement that comes with higher gearing is designed and intended to come from greater leverage and body position in use vs. assumed solely greater finger, hand, or wrist force. So, for example, a standard can might be fully cut and opened with less effort and fewer rotations, potentially as little as approximately three full rotations of the crank, though in exemplary embodiments reduced by approximately 30%. These gearing ranges assume that the tooth size on the two gears is substantially similar.

The embodiments shown in the Figures are designed to adapt to the type of plates commonly used in X-style can opener designs, achieving a significant improvement in gearing in combination with a longer crank while adding minimally to the number of new or added parts to existing can opener assemblies. The driving gear 131 and crank 130 assembly mount to the first plate 121 through the pivot point 120 where typically they would be secured with rivets or other connectors; this attachment point conserves parts and increases ease of construction. The exemplary embodiment is intended to open a standard can with approximately two full rotations or three to four ratcheted cycles of the crank, assuming each ratcheting cycle encompasses approximately 120-180 degrees.

The knob or crank in an exemplary embodiment might be generally one-sided (though other shapes and configurations, including asymmetric shapes, are viable and can work as well, and possibly with a rotatable knob at the end that allows the operator to turn the crank in a greater range of motion even when ratcheting) to enable rotations and re-winding in partial, ratcheted turns or complete, continuous rotations, while more readily maintaining natural hand and wrist positions to deliver force from engagement of larger muscle groups than standard can opener operation requires. It might also be designed for two possible hand or grip positions to better accommodate the user whether the device is being operated by ratcheting or even full rotational operation, by either holding to drive the crank with most force at the distal end of the crank (e.g., with the thumb placed at the distal end) or along the crank body and arm. Though, in an exemplary embodiment the crank might be designed to optimally driven by the thumb, or alternatively by the palm without need to grip the crank- but in either case not relying on the smaller muscle groups from cranking using turns by the finger tips.

The crank arm may be shaped to accommodate comfortably the thumb at its tip, or distal end, where the thumb, supported by the arm and shoulder muscles, are engaged for delivering body force as opposed to smaller finger muscles and structures. In an exemplary embodiment, the shape of the crank arm, including an angle or offset, is designed to accept the thumb near the tip or distal end to provide more drive pressure and input, such that the thumb of a user opening the can would end (when rotated forward away from the operator) closer to the head plates. Further, though separately, the handles might be angled or offset relative to the head plates, in an exemplary amount of ten to thirty-five degrees, where both of these elements individually (and more so together) allow the left and right hands and arms to operate in a more natural“V” position as opposed to in parallel to one another, thus enabling the arms to be in a more natural orthogonal position or angle relative to each another. An angled or offset crank also allows the crank to rest against the handles for storage— i.e., the crank is in a position where the tip or distal end is rotated to be pointing towards and closer to the parallel ends of the handles. The crank would also store more compactly when oriented in the opposite direction, towards the plates. More power can thus be achieved without limitations arising from finger tip or wrist rotational limits, comfort, or reduced strength/power delivery at the extremes, with the overall device still being compact enough to easily store (particularly when the device is stored with the crank adjacent to the handles).

The combination of handles and crank angle allows the right hand (assuming, as is typical, the can opener is right-handed) and arm to retract and extend in a more natural line with hand, wrist, arm, and shoulder movements to drive the crank forward while engaging larger muscle groups, and with more body mass behind the power stroke, thus enabling greater force application, while the longer (larger radius crank and driven more so by the thumb) provides more leverage and power during the power stroke. The combination of more leverage with more force delivered more comfortably through larger body motions (and larger muscle groups) enables delivery of more power to more comfortably operate the device with greater overdrive or gearing such as to operate more easily at faster cutting rates (i.e., fewer rotations per can being opened). Significantly, such a design and configuration allows operators with limited hand and finger motion to operate the opener without needing to grip the crank— even driving the crank, if desired or necessary, with the palm of the hand using mostly only arm and shoulder motions. It is equally possible to retract the crank with the palm or with only the light force needed to draw the crank back, or with one’s fingers (though without needing to grip) to prepare for the next power stroke, all without needing fingertip strength or mobility. Further, these elements, combined with full-range ratcheting, enable operators to adapt the power stroke range readily to their specific and unique comfortable and efficient range of motion.

Further still, exemplary and even preferred embodiments have ratcheting teeth placed closer to and around the outer perimeter of the internal gear assembly (the teeth either incorporated into the internal gear part or the crank assembly, with the corresponding teeth engaging whichever of these two parts that does not include the ratcheting teeth), enabling a greater number of ratcheting teeth (and corresponding grooves or gears) when incorporated on the outer perimeters of these assemblies and constructed without the need for a separate part. In an exemplary embodiment, the assembly that engages the teeth or ratcheting gears has four arms, each with two fingers, thus providing eight total teeth to spread the load borne by the overall assembly. Such a design shown allows the arms to flex to more easily (and more quietly allow reverse or slack drive motion) while providing for greater durability of the fingers (e.g. if constructed from plastic), with the fingers being less prone to wear or breakage since the load is spread over multiple such fingers. Naturally, the greater number of teeth and grooves also reduces slack drive (the distance or degrees of rotation over which the crank must be driven forward before it engages the first tooth, at reset or beginning of each drive or power stroke), thus providing effectively longer power strokes per hand crank, and potentially reducing the number of such rotations to open a can.

The axle for the internal gear need not necessarily be located at the main pivot point of the main plates or heads, particularly if implementing a range of overdrive gearing ratios, not all of which would provide for a convenient use of such positioning in conjunction with viable sizes of the inside driven gear (and particularly the tooth size). For example, with lesser degrees of overdrive/gearing, a smaller internal gear might be used, which would also tend to place the axle for this gear closer to the driven gear(s), and thus would require moving the axle placement on the internal gear closer to the driven gear(s), where it might be preferred to move that axle from the location of the main head plate pivot as shown in the figures. With overdrive of 2: 1 or higher (used with existing driven gear sizes), the internal axle position would still enable it to mount directly on the plate without interfering with the driven gear. With lower gearing ratios, that axle would tend to fall within the footprint of the inside driven gear, thus necessitating a bridge part (referred to as the‘Bridge’,‘L-Bridge’, or support member) to enable shifting the anchor point for the internal gear assembly on the plates further away from the inside driven gear, an example of which is shown in the Figures. In an exemplary embodiment, such a support member or‘L-Bridge’ could be formed and attached with a single stamped metal part (preferred for cost and simplicity of construction, though it could be molded in plastic as well and secured with fasteners). In one embodiment as shown, the crank and ratcheting assembly could be attached by a tubular section molded into and part of the crank assembly, thus reducing the number of components, cost and setup for simpler lower-cost manufacturing fabrication and assembly. Alternatively, while not as efficient in the number of parts and potential simplicity of assembly, the L-Bridge (or L- Bridge sub-assembly) could be constructed with such a connection tube connected to or being part of the L-Bridge. An exemplary design is shown in the Figures, where when the L-Bridge part is stamped and bent, its three feet can be directly connected to corresponding connection points or holes and fastened with coining or other known commercially-viable means without added fastener parts or assembly steps. In either case, a circular opening around the pivot point or center of the crank might be intentionally kept open to permit air flow into the assembly and inside the internal gear internal chamber to allow for easier cleaning and more effective drying. A molded bridge (such as from injection-molded, strengthened plastics) that provides an anchor point(s) located on the side of the bridge furthest from the location of the inside driven gear could also provide for the attachment point of the crank and ratcheting assembly, the rotational bearing surface, as well as for the internal gear housing.

At lower gearing, the overdrive gearing could also be accomplished with more common side-by-side gears, though the footprint of the gears assembly would be larger and more problematic to fit on the plates or heads as efficiently (without expanding the head plate size) and would also shift the position of the drive crank, while requiring a larger, higher-cost cover to protect the gears and for safer operation. Whereas such a functional cover is effectively provided with the use of an internal gear, thus avoiding extra part for such a function, along with other advantages, some referenced in this disclosure.

Further, while it is generally simpler to construct and attach a separate ratcheting fingers assembly in order to add ratcheting functionality (as shown in the Figures), such a part and the teeth or gears which they drive can each be incorporated or attached to either the crank assembly or internal gear assembly (i.e., as long as such fingers are secured to one part and the gears or teeth molded or constructed into the other).

The ratcheting teeth component or assembly can be constructed and accomplished in various manners. However, as disclosed in the Figures, an exemplary embodiment could be constructed from a single part, that would avoid the need for a reset spring, fasteners, or other components and yet be strong enough to be molded in plastic. Further, it could include design elements as shown that would avoid the potentially louder noises typically associated with using a reset spring to engage the fingers and provide for reverse ratcheting by flexing, thus snapping back after passing each tooth generally with some resulting sound. Lighter spring fingers reduce sound, yet reduce strength of the fingers. The exemplary embodiment disclosed in the Figures uses four arms, with each arm designed to flex over a longer distance, as the arms are designed and placed to mostly maximize their length (and thus flex). Further, each arm incorporates two tips, each more flexible than the arm portion itself. The tips which engage the drive teeth each are intended to contact the drive teeth/gears simultaneously, such that in this example, eight (8) fingers engage eight (8) separate grooves or gears such that the overall strength of the teeth and ability to withstand the greater forces of higher gearing or overdrive would be more durable even if, for example, molded from plastic as indicated in one single part. Thus, with multiple teeth or fingers engaged to drive the internal gear and power the device, such fingers can be made more flexible, which both reduces excess noise as the fingers snap back as they pass over each peak or gear tooth, while importantly also providing more durable overall driving and greater distribution of forces more evenly around both the ratcheting and internal gear assemblies (more so than two such arms would, though more than four such arms for commercial purposes and potential materials would generally not be required).

An advantage of the disclosed embodiments is that the device may be manufactured with minimal adaptations to certain common can opener platforms and limited changes to existing components, focusing on adaptation of the overdrive, ratcheting, and crank elements to the basic X-shaped can opener design. Manufacture thus requires minimal modification to existing can opener plates/heads to adapt the new or replacement components. Important is the commercial advantage of having a small number of extra parts or components needed to adapt embodiments of the present invention to at least one of the existing platforms. Further, the overdrive assemblies (internal gear, driven gear, crank, and ratcheting assembly) are only mounted to one side of the main plate, meaning no commercial changes need to be made to the cutting side of the main plate (other than the longer axle needed to accommodate the assembly).

The ratcheting elements of the design in some embodiments provide the ability to both fully and continuously rotate the crank during operation as well as ratcheting within a variable range determined by the operator and/or the application (e.g., especially for short cans being opened on flat surfaces the exemplary crank is longer than the can height, and thus would contact the surface unless ratcheted to utilize only a portion of the rotation range). The separation of the ratcheting drive element (gear teeth) from the gear drive (i.e., separate teeth on different faces/planes of the internal gear) is central to many of the performance advantages and flexibility in operating efficiently in both continuous cranking mode and ratcheting. Other ratcheting mechanisms (including pawl drives and others) generally use only one set of teeth for both ratcheting and driving (i.e., allowing ratcheting by the tooth - or teeth - rotating backwards over the grooves or gears). In some embodiments, the ratcheting teeth, and spaces/di stance between them, are much smaller or lighter gauge/strength than the internal grooves or gear, thus making for less resistance when ratcheting backwards to reset the crank, and with a greater number of grooves located and spread over a larger diameter outer wall, thus also with less slack before the gears re-engage and power the drive and cutting gears. In some embodiments, locating the ratcheting teeth on the largest diameter possible enables the optimal combination of finest increments and larger teeth for the ratchet spring to engage without slipping or skipping (including less prone to wear and failure over time, if for example, the teeth were smaller). Additionally, with the two or more sets of teeth and grooves/gears (the ratcheting teeth and grooves also on a separate plane allows the largest radius for both set of teeth and thinner, more compact, internal gear - vs., for example if both sets were oriented similarly and more or less concentric). Also, by locating the drive teeth for the crank on the outer most portion of the internal gear assembly great torque is imparted with less force on the teeth collectively (vs. if the grooves were located closer to the axle) and thus less force and wear on the components (as well as with more teeth, additionally then less wear "per tooth" for each rotation of the cutting wheel).

Not shown is a simple pin, switch, button or other element (or other approaches that are available) to temporarily lock the internal gear to the crank, in order to switch between ratcheting and non-ratcheting, if desired (i.e. to enable potentially backtracking while cutting to recut a section, for example, that might not have cut fully on the first pass).

Also not shown is a spring reset mechanism that might be incorporated, more so for an embodiment of the device that primarily or exclusively ratchets vs. one where the crank can make a full 360 degree continuous rotation while cranking - the spring assisting in resetting the crank to a fixed position at the position associated with the beginning or start of the drive rotation.

Other lesser elements, may not be disclosed here, including designs of the internal gear with slots or spaces to enable it to be more easily washed. Or, alternatively, an easy disassembly means, also for cleaning.

The aforementioned embodiments have been described by way of example only, and various other modifications of and/or alterations to the described embodiments may be made by persons skilled in the art without departing from the scope of the invention as specified in the claims.

Claims

What is claimed is:

1. An apparatus for opening cans, comprising:

a first handle having a proximal end portion and a distal end portion;

a second handle having a proximal end portion and a distal end portion;

a crank having a grip and a toothed, internal recess comprising a driving gear; and

a first driven gear housed within and engaged with the driving gear,

2. The apparatus of claim 1, wherein

the first driven gear is connected to the proximal end of the first handle by a first axle oriented orthogonally to the teeth of the driving gear and coupled to a second driven gear on the same axle but on the opposite side of the first handle relative to the crank and first driven gear,

the second driven gear is coupled to a first cutting piece configured to contact a can and exert torque on the can when the second and a third driven gear are engaged and the crank is turned,

the third driven gear is configured to become engaged with the second driven gear and being coupled to a second cutting piece by a second axle running through the second handle, and

the first cutting piece comprises one of a traction wheel and a cutting wheel, and the second cutting piece comprises the other of a traction wheel and a cutting wheel.

3. The apparatus of claim 2, wherein the crank that turns the driving gear further comprises a ratcheting mechanism having an unlimited range of motion with respect to rotation of the crank.

4. The apparatus of claim 3, wherein the first handle is connected to a first plate through which runs the first axle, the traction wheel and the second driven gear are positioned on the first axle on the opposite side of the first plate relative to the first driven gear and the toothed, internal recess comprising the driving gear, and the ratcheting mechanism, the toothed, internal recess comprising the driving gear, and the first driven gear are positioned on the first axle on the same side of the first plate relative to each other.

5. The apparatus of claim 2, wherein a plane formed by the first and second handles is offset from a plane containing the driving gear by an angle in a direction orthogonal to the plane formed by the first and second handles.

6. The apparatus of claim 5, wherein the angle is in the range of ten to thirty-five degrees.

7. The apparatus of claim 1, wherein the crank is offset at its distal end.

8. The apparatus of claim 2, further comprising a reducing gear system.

9. The apparatus of claim 8, wherein the reducing gear system provides a gear ratio in the range of about 1.4: 1 to about 4: 1.

10. The apparatus of claim 2, wherein the grip of the crank is configured to lie within the same plane as the first and second handles, allowing the handles and the grip of the crank to be grasped in one hand such that the apparatus may be operated one-handed.

11. Optional The apparatus of claim 3, wherein the first and second handles are configured to interlock when closed such that the cutting pieces of the apparatus can remain fully locked and engaged with a can and to reduce twisting from torsional stress.

12. The apparatus of claim 3, wherein the ratcheting mechanism comprises a plurality of arms with distal teeth at the ends of each pawl configured to engage grooves formed into the back side of the driving gear assembly.

13. The apparatus of claim 3, wherein a support member is disposed between the driving gear and the first driven gear, the support member having a first end portion comprising a third axle about which the crank may be rotated, and a second end portion located inside the toothed, internal recess comprising the driving gear.

14. The apparatus of claim 3, where the ratcheting mechanism is comprised of a sprag ratchet drive comprising of sprags placed in cavities formed between the overlapping space of crank-ratchet assembly and a 360 wall formed on the back side of the internal gear.

15. A method of opening a can comprising:

obtaining an apparatus comprising:

a first handle having a proximal end portion and distal end portion, a second handle having a proximal end portion and a distal end portion,

a crank having a grip and a toothed, internal recess comprising a driving gear,

a first driven gear housed within and engaged with the driving gear, and

first and second cutting pieces configured to surround a lip of a can having a lid,

the first cutting piece comprising one of a traction wheel and a cutting wheel, and the second cutting piece comprising the other of a traction wheel and a cutting wheel;

positioning the apparatus such that the traction wheel and the cutting wheel surround a lip of a can having a lid;

squeezing the distal ends of the first and second handles together such that the circular blade cuts into the lip of the can having a lid; and turning the crank in a forward (driving) direction such that the driving gear drives the driven gears, turning the cutting wheel and cutting the lid of the can.

16. The method of claim 15, wherein

the first driven gear is connected to the proximal end of the first handle by a first axle oriented orthogonally to the teeth of the driving gear and coupled to a second driven gear on the same axle but on the opposite side of the first handle relative to the crank and first driven gear; and

the second driven gear is coupled to a first cutting piece configured to contact a can and exert torque on the can when the second and a third driven gear are engaged and the crank is turned, the third driven gear configured to become engaged with the second driven gear and being coupled to a second cutting piece by a second axle running through the second handle.

17. The method of claim 15, wherein a reducing gear system is used to reduce the torque required to open the can.

18. The method of claim 15, wherein a ratcheting mechanism allows the user to endlessly drive the drive gear without releasing the crank and without readjusting the position of their hand on the handle.

19. An apparatus for opening cans, comprising:

a first handle having a proximal end portion and a distal end portion, the proximal end portion being connected to a first plate;

a second handle having a proximal end portion and a distal end portion, the proximal end portion being connected to a second plate;

a crank having a grip and being connected to a driving gear, the crank comprising a ratcheting mechanism having an unlimited range of motion with respect to rotation of the crank; and a first driven gear engaged with a non-coaxial driving gear to provide overdrive, the first driven gear being adjacent to, or within, the driving gear; the first driven gear being connected to the proximal end of the first handle by a first axle oriented orthogonally to the teeth of the driving gear and coupled to a second driven gear on the same axle but on the opposite side of the first plate relative to the crank, ratcheting mechanism and first driven gear.

20. The apparatus of claim 19, wherein

the second driven gear is coupled to a first cutting piece configured to contact a can and exert torque on the can when the second and a third driven gear are engaged and the crank is turned,

the third driven gear is configured to become engaged with the second driven gear and being coupled to a second cutting piece by a second axle running through the second handle, and

the first cutting piece comprises one of a traction wheel and a cutting wheel, and the second cutting piece comprises the other of a traction wheel and a cutting wheel.