This invention relates to powering mobile devices, especially handheld portable personal electronic devices such as mobile phones that contain a rechargeable battery. The invention relates particularly to keeping a personal electronic device charged and available for use while remaining fully portable, without requiring the device to remain connected to a charger during a lengthy charging period.

Mobile phones will be used in this specification to exemplify personal electronic devices. However, the invention is not limited to mobile phones and can be used with other personal electronic devices such as tablets, laptop computers or music players.

Mobile phones have become an essential of modern life and so demand readily- available and efficient charging solutions. Whilst battery life has improved in recent years, high usage can deplete the battery of a mobile phone well within a day. Also, a battery can run out of charge at unpredictable and inconvenient times. Mobile phone users therefore require frequent and ongoing access to chargers and to power sources for such chargers. However, chargers or power sources may not be available to a user where and when needed, especially when the user is away from home or work or is travelling. Even if a charger connected to a power source is available, the charger may not be of the correct type. For example, an available charger may have a connector that is not appropriate for the type of phone to be charged.

Even where a user has access to a charger and a power source, another challenge is the need for the phone to remain connected to the charger throughout a lengthy charging period. This wastes time, may restrict the user’s freedom of movement and can risk the phone being stolen if it is left unattended in a public place while charging.

Portable chargers and charging cases with onboard power supplies are known for prolonging the battery life of a mobile phone. However, portable chargers and charging cases themselves need to be charged eventually and so merely defer rather than address the various challenges of charging.

Some of the challenges of charging can be addressed by replacing a depleted battery with a freshly charged battery. For example, it is known to power portable equipment such as hand-held drills using readily detachable and swappable batteries. Swapping a battery in this way requires some dexterity of the user but can be done much more quickly than waiting for a depleted battery to be recharged.

However, swappable batteries are little better than portable chargers because they require a user to carry an additional battery and to remember to keep that battery charged. Also, if equipment is designed for easy access to a battery, this increases the risk of the battery becoming detached inadvertently, compromises resistance to the ingress of moisture and dirt, and reduces design freedom. In this respect, it is notable that modern mobile phone designs do not generally allow users to replace an internal battery, instead concealing the battery within a sealed housing that should only be opened by authorised service personnel. Indeed, a user-replaceable battery would be incompatible with a protective case as it would require the phone to be removed from the case each time the battery is to be swapped.

The invention addresses the challenges of swapping batteries to keep a mobile phone or other personal electronic device charged and available for immediate portable use.

Against this background, the invention resides in a battery swapping unit for removing a battery from, and attaching a battery to, a case of a personal electronic device. The unit comprises: an insertion path along which an assembly of the case and the battery can be inserted into and withdrawn from the unit, the insertion path extending to a separator for separating the battery from the case; a case path communicating with the insertion path and extending downstream from the separator for guiding the case to a reassembly position in the unit; a battery path communicating with the insertion path and extending downstream from the separator for guiding the battery to a charging position in the unit; and a reassembly mechanism for moving the battery from the charging position to the case at the reassembly position.

Advantageously, the reassembly mechanism may be operable by movement of the case along the case path into the reassembly position to move the battery from the charging position to the reassembly position. For example, the reassembly mechanism can comprise a platform that bridges between the case path and the battery path and that is movable by applying insertion force from the case to the platform to move the battery from the charging position to the reassembly position. Conveniently, the platform may be pivotable in response to impingement of the case with the platform to pivot or swing the battery from the charging position to the reassembly position. The platform may comprise a first base portion aligned with the case path and a second base portion aligned with the battery path to support the battery in the charging position. The platform may also comprise a wall upstanding from the second base portion of the platform, the wall being aligned with the battery path and opposed to the case path across the battery path. A flange extending from the wall may define a shoulder that protrudes into the battery path.

Elegantly, the battery path may diverge from the case path downstream of the separator and then converge with the case path toward the reassembly mechanism. For example, the battery path may be defined by a guide that is curved along its length to reverse inclination, relative to a vertical axis, of a battery following the battery path.

The separator suitably comprises a blade that faces upstream on the insertion path, the blade having a face that is inclined relative to the insertion path and that is aligned with the battery path. The blade may further comprise a flange that lies in a plane substantially aligned with the insertion path, outboard of the inclined face. The blade may also be mounted for pivotal movement about a pivot axis. In that case, the separator can further comprise a tab that protrudes into the battery path, the tab being opposed to the blade about the pivot axis to pivot with the blade in an opposed angular direction.

A plunger at a downstream end of the case path may extend upstream along the case path alongside the charging position. The plunger may conveniently be supported by the reassembly mechanism. The plunger can retract in a downstream direction in response to downstream movement of the case along the case path. When the plunger is deployed, at least one charging contact of the plunger may be positioned to connect electrically with a battery at the charging position.

The unit may contain a battery at the charging position and an additional battery at an intermediate position on the battery path, upstream of the battery at the charging position.

The inventive concept also embraces a corresponding method of removing a depleted battery from, and attaching a charged battery to, a case of a personal electronic device. The method comprises: inserting an assembly of a case and a depleted battery into a charging unit along an insertion path; separating the depleted battery from the case in the unit; moving the case along a case path to a reassembly position in the unit; directing the depleted battery onto a battery path leading to a charging position in the unit; moving a charged battery from the charging position to the reassembly position; at the reassembly position, assembling the case with the charged battery; withdrawing the assembly of the case and the charged battery from the unit; and moving the depleted battery to the charging position.

The charged battery may be moved from the charging position to the case at the reassembly position in response to movement of the case to the reassembly position. For example, insertion force applied to the case can move the charged battery from the charging position to the reassembly position.

The depleted battery can be held at an intermediate position in the unit after separating the depleted battery from the case and before moving the depleted battery to the charging position. For example, the depleted battery can be held at the intermediate position by blocking the battery path with the charged battery. The depleted battery can then be released from the intermediate position to the charging position after the charged battery is moved from the charging position to the reassembly position. The depleted battery can be released for movement to the charging position by withdrawing the assembly of the case and the charged battery from the unit.

The depleted battery may diverge from the case after separation and then may converge with the case toward the charging position. On that journey between separation from the case and reaching the charging position, inclination of the depleted battery may reverse relative to a vertical axis.

The depleted battery may be separated from the case by inserting a blade of the unit into a gap or slot between the depleted battery and the case and then prising the depleted battery away from the case in consequence of insertion force applied to the assembly. The depleted battery may, for example, be prised away from the case by forcing the battery across a face of the blade that is inclined relative to the insertion path. The depleted battery may also be prised away from the case by pivoting the blade in response to movement of the depleted battery along the battery path. Conveniently, insertion force applied to the assembly may be used to drive the depleted battery along the battery path while a part of the depleted battery remains engaged with the case. A restraint such as the abovementioned plunger may be employed to hold the charged battery at the charging position. The restraint may then be retracted or withdrawn to release the charged battery in response to movement of the case to the reassembly position. The battery can conveniently be charged via the deployed restraint. The case can be urged into the reassembly position against deployment bias of the restraint.

The depleted battery can be separated from the case against magnetic attraction between the case and the depleted battery. Conversely, assembly of the case with the charged battery may be assisted by magnetic attraction between the case and the charged battery.

The inventive concept extends to a case for a personal electronic device, or a personal device having a case, adapted for use with the battery swapping unit of the invention. For that purpose, the case comprises a removable external battery to provide electrical power to the device, wherein an edge of the battery has a protruding lip that borders a slot, that slot facing toward an edge of the case in a direction substantially parallel to a face of the case.

The edge of the battery may protrude from the face and the slot may be defined between the lip and the face. The edge of the battery may be inboard of the edge of the case. The battery may be at least partially accommodated in a recess in the face, and may be partially surrounded by a bank formation that protrudes from the face and opens toward the edge of the case. In that instance, the lip of the battery may be disposed between parallel limbs of the bank formation. The limbs of the bank formation may taper in thickness toward the edge of the case.

The case may be generally cuboidal, comprising relatively long side edges and relatively short top and bottom edges joining front and rear faces. In that instance, the slot may face toward and lie substantially parallel to the bottom edge of the case.

Where the case is a charging case, a receptacle may be arranged to receive and retain the device for transmission of electrical power from the case to the device.

In summary, an assembly of a case and an outer battery is inserted into a battery swapping unit to encounter a separator blade that separates the battery from the case. After separation, a case path guides the case to a reassembly position and a battery path guides the battery to a charging position. A reassembly mechanism is operable to move the battery from the charging position to the case at the reassembly position.

The battery is attachable to a rear face of the case. A slot at an edge of the battery faces toward an edge of the case in a direction parallel to the rear face. On insertion of the assembly into the unit with that edge of the case leading, the separator blade engages in the slot to prise the battery off the case.

The case may be a charging case into which a personal electronic device such as a phone can be fitted. Alternatively, the case may form part of, or be integral with, the device itself.

Where the case is a charging case, each device will have a matching charging case tailored to the device but external features of the charging case including the size and configuration of the battery and surrounding features can be universal. This means that a battery swapping unit of the invention can work with a variety of devices of different shapes and sizes because the parts that interact with the unit will be the same from one device to the next.

In order that the invention may be more readily understood, reference will now be made, by way of example, to the accompanying drawings in which:

Figure 1 is a perspective view of a battery swapping unit of the invention;

Figure 2 is a perspective view of an assembly comprising a mobile phone housed in a case of the invention, the case further including an outer battery of the invention;

Figure 3 corresponds to Figure 2 but shows the outer battery partially removed from the case; and

Figures 4 to 13 are a sequence of side views showing the operation of a battery swapping mechanism disposed within the unit shown in Figure 1.

Referring firstly to Figures 1 of the drawings, a battery swapping unit 10 of the invention can be used in domestic or commercial applications such as homes, offices, bars or airports and may be wall-mounted, as shown, or free-standing. The battery swapping unit 10 comprises a battery swapping mechanism 12, 60 concealed within an outer housing 17. The housing 17 also contains and conceals a controller 18 and an optional power source 22. The controller 18 controls operation of the battery swapping unit 10 and provides information to a user via an external user interface 20 of the unit 10, for example status information as to the charge level of a battery being charged within the unit 10 and confirmation that the unit 10 has sufficient power. In this respect, the unit 10 can be supplied with mains AC power, in which case the internal power source 22 of the unit 10 may comprise a transformer, or a transformer may be situated outside the unit 10 to supply lower-voltage DC power to the unit 10. The internal power source 22 may also comprise electrical power storage, such as an internal battery, so that the unit 10 can recharge one or more batteries even if the unit 10 is disconnected temporarily from an external power supply. Figures 2 and 3 show a conventional mobile phone 14 encased in a charging case 16 of the invention. The case 16 follows the general outline of the phone 14 and therefore is generally rectangular, with two long side edges and shorter top and bottom edges disposed between opposed front and rear faces.

The front face of the case 16 defines a complementary receptacle that receives and engages the phone 14 in a snap-fit arrangement. The receptacle is therefore tailored to a specific model of phone 14 of particular dimensions. However, the exterior of the case 16 can be of standard dimensions. Thus, a range of cases 16 can be created to fit a range of different phones 14 but each case 16 of the range may be, outwardly, dimensionally identical apart from in the shape and size of its receptacle.

When a phone 14 is engaged within the receptacle, the case 16 is then connected to the phone 14 through mutually-aligned internal contacts 30 in the case 16 and external ports or contacts 32 of the phone, most commonly disposed on a bottom edge of the phone 14. When connected, those contacts 30, 32 can convey electrical power from the case 16 to an internal battery of the phone 14.

To provide power to the phone 14, the case 16 supports an exchangeable outer battery 26 that is removable from and reattachable to the case 16. When attached to the case 16, mutually aligned contacts 42 of the outer battery 26 and the case 16 connect the outer battery 26 electrically to the internal battery of the phone 14 via the internal contacts 42 in the case. In this example, the outer battery 26 is mounted on the rear face of the case 16 opposed to the receptacle that receives the phone 14. Specifically, the outer battery 26 is received in a complementary generally rectangular recess 28 in the rear face. The recess 28 is offset longitudinally toward the bottom edge of the case 16, leaving space for an aperture 34 that accommodates camera lenses of the phone 14 near the top edge of the case 16.

Advantageously, the recess 28 allows substantially flush-fit mounting of the outer battery 26 with respect to the contours of the case 16 adjoining the recess 28. Nevertheless, the outer battery 26 can protrude slightly from the recess 28. In that case, convex curvature around the periphery of an external or rear face of the outer battery 26 flows smoothly into the surrounding contours of the case 16. This ensures that an assembly 24 of the phone 14, case 16 and outer battery 26 is comfortable to hold and unlikely to snag when placed in a pocket or a bag, which could otherwise risk inadvertent detachment of the outer battery from the recess.

The long sides of the recess 28 extend parallel to the side edges of the case 16 whereas short upper and lower sides of the recess 28 extend parallel to the top and bottom edges of the case 16. Of the two short sides of the recess 28, the upper side is closer to the top edge of the case 16 and the lower side is closer to the bottom edge of the case 16.

A base of the recess 28 is surrounded by a peripheral wall 36, upstanding orthogonally or at an obtuse angle from the base. The peripheral wall 36 has two long sides and an upper side that define the corresponding sides of the recess 28. Conversely, a lower side of the peripheral wall 36 is parallel to but inset from the lower side of the recess 28.

The two long sides and the upper side of the peripheral wall 36 are deeper than the lower side of the peripheral wall 36. This is because the recess 28 is surrounded on those three sides by a bank 44 that protrudes above the surrounding level of the rear face of the case. The bank 44 thickens the case 16 locally to accommodate the edge thickness of the outer battery 26 in the recess. There is a sharp transition between the top of the bank 44 and the peripheral wall 36 of the recess 28, which in this example is substantially orthogonal or acutely angled with respect to the top of the bank 44. When viewing the case 16 from the rear, the bank 44 has a C-shape that opens toward the bottom edge of the case 16. Limbs of the C-shape extend parallel to each side of the case 16 and taper in thickness so that the case 16 reduces in thickness from the top of the bank 44 toward the bottom edge of the case 16. The height or thickness of the bank 44 defines the depth of the peripheral wall 36 of the recess 28. Consequently, the tapering thickness of the bank 44 determines the lesser height of the lower side of the recess 28 and of the lower side of the peripheral wall 36 that is inset within it.

The outer battery 26 complements the shape and depth of the recess 28 and therefore is also substantially rectangular, with parallel upper and lower ends matching the lengths of the corresponding sides of the recess 28. The outer battery 26 also has parallel long sides but those sides are slightly shorter than the corresponding sides of the recess 28. As a result, when the outer battery 26 is installed in the recess 28 with the upper side of the outer battery 26 abutting the upper side of the recess 28, the lower end of the outer battery 26 lies parallel to but spaced upwardly from the lower side of the recess 28.

The outer battery 26 has an underside that is shaped to fit snugly within the peripheral wall 36 of the recess 28 but has a stepped profile 39 at its lower end. The stepped profile 39 comprises an inner wall 40 that is inclined inwardly toward the base and the upper side of the recess 28. When the outer battery 26 is received in the recess 28, the inner wall 40 lies within the lower side of the peripheral wall 36 of the recess 28. The stepped profile 39 further comprises a flange or lip 38 at the lower end of the outer battery 26 that surmounts the inner wall 40 and protrudes toward the bottom edge of the case 16, extending outboard of the lower side of the peripheral wall 36 of the recess 28. The lip 38 is spaced outwardly from the case 16 and the lower side of the recess 28 to define a transverse slot 33 beneath the lip 38 between the tapering limbs of the C-shaped bank 44, that slot 33 also facing toward and opening toward the bottom edge of the case 16.

Electrical connection between the case 16 and the outer battery 26, when installed in the recess 28, is preferably effected by contacts 42 on the underside of the battery 26 aligned with complementary contacts on the base of the recess 28.

In this example, as noted above, the outer battery 26 has a convex-curved external face that continues the cross-sectional curvature of the bank 44 around the recess 28. The convex curvature of the external face also follows the tapering thickness of the bank 44 toward the bottom edge of the case 16. This also ensures that the assembly 24 of the phone 14, case and outer battery 26 is comfortable to hold and unlikely to snag.

Magnetic attraction holds the outer battery 26 within and aligned with the recess 28 as described above. Once received in the recess 28, the outer battery 26 is also located around its periphery by the surrounding peripheral wall 36 of the recess 28. In other examples, the outer battery 26 may instead, or additionally, be held in the recess 28 by other mechanical engagement provisions such as snap-fit formations. In any event, the outer battery 26 is held in the recess 28 strongly enough that it is it difficult to prise the battery 26 off the case by hand or otherwise to disengage the battery 26 from the case 16 inadvertently.

Moving on now to Figures 4 to 13, these drawings show the battery swapping mechanism 60 that is concealed within the outer housing 17 of the battery swapping unit 10 shown in Figure 1.

The swapping mechanism 12, 60 is aligned with, and communicates with, an elongate opening 46 that penetrates a substantially horizontal top wall of the housing 17. The opening 46 is slightly larger than the top plan outline, or end silhouette, of the assembly 24 of the phone 14, case 16 and outer battery. 26 This ensures that the elongate assembly 24 is a close sliding fit in the opening 46 when the assembly 24 is inserted into the opening 46 in a swapping operation, to enter the swapping mechanism 12, 60 in a substantially vertical direction.

When swapping a depleted outer battery 26 for a fresh outer battery 58, a user holds the assembly 24 in one hand in an upright orientation with the long sides of the case 16 substantially vertical. The user then pushes the assembly 24 down to insert a lower portion of the assembly 24, including the outer battery 26, into and through the opening 46 and into the housing 17 along a substantially vertical axis as shown in Figure 4.

As will be explained, the insertion movement of pushing the lower portion of the assembly 24 fully into the housing 17 causes the assembly 24 to interact with the swapping mechanism 12, 60 that is aligned with the opening 46 within the housing 17. That interaction separates the depleted battery 26 from the case 16 and engages a freshly-charged battery 58 with the case 16 before the insertion movement is reversed to withdraw the resulting assembly 24 from the housing 17. It should be noted that references in this specification to a depleted battery 26 do not require that battery 26 to be fully or even mainly depleted of charge. A depleted battery 26 is simply a battery 26 that a user wishes to charge, irrespective of its level of charge.

A protruding upper portion of the assembly 24 remains outside the housing 17 throughout a battery swapping operation. The user can thereby pull the assembly 24 upwardly out of the housing 17, complete with the freshly charged battery 58 engaged with the case 16. The upper portion can conveniently remain in the user’s grasp if the user wishes to withdraw the assembly 24 immediately from the housing 17 in an upward movement. However, the user can instead release the upper portion before withdrawal to leave the assembly 24 engaged with the unit 10 if desired. This allows the unit 10 to be used as a convenient storage point for the assembly 24 to be withdrawn later, for example overnight.

Within the housing 17, an insertion path 48 extends substantially vertically from the opening 46 to the swapping mechanism 12, 60. On reaching the swapping mechanism 12, 60 as shown in Figure 4, the insertion path 48 divides into a case path 80 and a battery path 50 that diverges from the case path 80. When the assembly 24 is inserted into the housing 17 along the insertion path 48, the swapping mechanism 12, 60 separates the depleted battery 26 from the case 16. The case 16, containing the phone 14, is then constrained to follow the case path 80 and the depleted battery 26 is then constrained to follow the battery path. The case path 80 leads the case 16 to a reassembly position whereas the battery path 50 eventually leads the battery 26 to a charging position at which the battery 26 is charged. A reassembly mechanism, exemplified here by a movable platform 78 operated by movement of the case 16, moves an already charged battery 58 from the charging position to the case 16 at the reassembly position.

An upper end of the swapping mechanism 12, 60 comprises a horizontally-extending separator blade 82 positioned at the inner end of the insertion path 48. The blade 82 has a hook profile comprising an inclined inner portion terminating in an outer flange. In an operational position of the blade 82, the flange extends parallel to the insertion path 48and has a free edge facing the opening 46 in the housing 17. A front face of the blade 82 is aligned with the case path 80 and an opposed rear face of the blade 82 is aligned with the battery path 50. The profile of the blade 82 separates the depleted battery 26 from the case 16 in a wedging action, directs the battery 26 onto the battery path 50 along the inclined inner portion and allows the case 16 to continue past the flange and onto the case path 80.

The blade 82 is pivotable about a horizontal pivot axis and is integral with a tab 54 that extends from the blade 82 in mutual opposition about the pivot axis. Springs 52 acting in compression against the rear of the blade 82 bias the blade 82 into the operational position in which the free edge of the blade 82 lies at the junction between the case path 80 and the battery path 50. The blade 82 pivots against the bias of the springs 52 to prise a depleted battery 26 out of the recess 28 in the case 16 and to provide clearance for the lower portion of the assembly 24, when fitted with a charged battery 58, to be withdrawn along the case path 80 and the insertion path 48 and back out of the housing 17 through the opening 46.

In this example, the case path 80 follows a substantially straight line that extends substantially vertically in alignment with the insertion path 48 and the slot 33. Conversely, the battery path 50 is a curved path whose upper end diverges from the case path 80 at an acute angle and whose lower end converges with the case path 80 at an acute angle. Thus, in side view, the case path 80 and the battery path 50 describe a D-shape between them. A depleted battery 26 reaching the lower end of the battery path 50 can thereby be transferred onto the case path 80 in a subsequent swapping operation, after recharging, to be reengaged with the case 16 as a charged battery 58 before the resulting assembly 24 is withdrawn from the housing 17.

The curvature of the battery path 50 is defined by an ogee-curved guide strip 56. When following the battery path 50, the depleted battery slides down along the guide strip 56 with its movement optionally assisted by a series of rollers 57 that lie parallel to and slightly proud of the guide strip 56.

The rear face of the blade 82 and the upper end of the guide strip 56 are downwardly convergent to define a mouth of the battery path 50 that receives a lower end of a depleted battery 26. The lower end of the depleted battery 26 then engages the tab 54 of the blade 82, causing the flange of the blade 82 now lying between the battery 26 and the recess 28 to pivot away from the recess 28 in an action that prises the battery 26 further out of the recess 28. At their lower ends, the case path 80 and the battery path 50 are joined by a reassembly mechanism that in this example comprises a pivotable platform 78. The platform is generally L-shaped in cross-section, comprising a forwardly-extending base plate 72 and an upright wall 66, and is pivotable about a horizontal pivot axis that lies on a vertical plane intersecting the base plate 72 close to the wall 66. An outboard portion 70 of the base plate 72 is disposed at the lower end of the case path 80 and an inboard portion 68 of the base plate 72, stepped above the outboard portion 70, is disposed at the lower end of the battery path 50 adjoining the upright wall 66.

The outboard portion 70 of the base plate 72 supports a spring-loaded plunger 74 that is biased upwardly and spaced forwardly from the wall 66 of the platform 78 by the width of the inboard portion 68 of the base plate 72. When extended, the plunger 74 retains a battery 26 at the lower end of the battery path 50 resting on the inboard portion 68 of the base plate 72 and lying against the wall 66. When its lower end reaches the inboard portion 68 of the base plate 72, the depleted battery 26 is held in an inclined orientation at an acute angle to the vertical, with the rear face of the battery 26 lying against the wall 66. The plunger 74 also supports one or more charging contacts 76 that are cooperable with opposed complementary contacts 42 on the underside of the battery 26, 58. In this way, a depleted battery 26 is charged over a period of time to become a charged battery 58.

The inboard portion 68 of the base plate 72 could also, or alternatively, support one or more charging contacts that are cooperable with opposed complementary contacts at the lower end of a battery. The weight of the battery 58 would thereby maintain an electrical connection between the contacts 72 of the battery 58 and the charging contacts of the base plate 72.

At its upper end, the wall of the platform 78 terminates in a rearwardly-extending flange 64. Springs 62 acting in tension on that flange 64 bias the platform 78 about the pivot axis into a receiving position in which the wall 66 is aligned with the guide strip 56 defining an upper portion of the battery path 50. In the receiving position, the wall 66 of the base plate 72 thereby becomes a continuation of the guide strip 56 to define a lower end portion of the battery path 50. The flange 64 at the top of the platform 78 is largely recessed behind the guide strip 56 but defines a shallow forwardly-protruding shoulder beneath the lower end of the guide strip 56. When an assembly 24 of phone 14, case 16 and depleted battery 26 is inserted into the opening 46 of the housing 17 and advances along the insertion path 48 to encounter the swapping mechanism 12, 16 as shown in Figure 4, the free edge of the flange at the top of the blade 82 enters the slot 33 between the lower end of the battery 26 and the case 16. Initially by virtue of its inclined inner portion and then by pivoting driven by interaction between the lower end of the battery 26 and the tab 54, the blade 82 prises the battery 26 out of the recess 28 of the case 16 with further downward movement of the assembly 24 along the insertion path 48 as shown in Figure 5 and 6. Initially, the blade 82 lifts the lower end of the battery 26 rearwardly away from the case 16 as the battery 26 pivots about a fulcrum or horizontal axis defined by the upper peripheral wall 36 of the recess 28 bearing against the upper end of the battery 26. In this way, the battery 26 is initially driven down into the mouth of the battery path 50 by virtue of the downward insertion force that the user applies to the upper portion of the assembly 24.

The curvature of the battery path 50 turns the depleted battery 26 about a horizontal axis as the battery 26 progresses down the battery path 50. Thus, that curvature pulls the upper end of the battery 26 out of the recess 28 after the blade 82 has pulled the lower end of the battery 26 out of the recess 28. This two-stage pivoting movement of the battery 26 in opposed angular directions relative to the case 16 overcomes magnetic attraction or other engagement that is strong enough to make it difficult for the battery 26 to be prised off the case 16 by hand or otherwise to be disengaged from the case 16 inadvertently.

When the upper end of the depleted battery 26 disengages from the upper peripheral wall of the recess 28, the battery 26 continues to move down the battery path 50 under the force of gravity. In doing so, the battery 26 continues to turn about a horizontal axis to the extent that its inclination to the vertical reverses as the battery 26 approaches the lower end of the battery path 50. Initially, downward movement of the battery 26 along the battery path 50 is resisted by the flange 64 at the top of the wall 66, which defines a shoulder protruding forwardly into the battery path 50. The battery 26 is held at that intermediate position by the shoulder at its lower end and by the tab 54 of the biased separator blade 82 still acting against the upper end of the battery 26 as shown in Figure 7.

Meanwhile, the case 16 containing the phone 14 continues to move down the case path 80 under insertion force applied by a user until the bottom edge of the case 16 encounters and depresses the plunger 74 as shown in Figure 8. This disengages the plunger 74 from the charged battery 58, freeing the charged battery 58 to move away from the wall 66 of the platform 78. The bottom edge of the case 16 then bears against the outboard portion 70 of the base plate 72 of the platform 78 at the lower end of the case path 80.

In principle, the case 16 could be left resting lightly on the plunger 74 without initiating further action, for example if allowing a depleted battery 26 a period of time to be charged. However, the swapping mechanism 12, 60 is intended to swap a charged battery 58 for the depleted battery 26, in which case a fresh battery 58, previously depleted but now charged, is already present on the inboard portion 68 of the base plate 72 at the lower end of the battery path 50 and is ready to be docked with the case 16.

When resting on the inboard portion 68 of the base plate 72, the charged battery 58 blocks downward movement of the depleted battery 26 along the battery path 50. The depleted battery 26 is thereby held at the intermediate position sandwiched between the rear of the charged battery 58 and the guide strip 56. As mentioned above, the depleted battery 26 is also retained temporarily by the shallow shoulder defined by the flange 64 extending from the wall 66 of the platform 78 and by the tab 54 of the separator blade 82.

As shown in Figure 9, further downward movement of the case 16 under insertion force applied by a user presses down on the outboard portion 70 of the base plate 72 via the depressed plunger 74, causing the platform 78 to pivot about the pivot axis against the bias of the springs 62. This pivoting movement swings the wall 66 of the platform 78 into a more upright orientation, hence pressing against the rear face of the charged battery 58 resting on the platform 78 and bringing that battery 58 substantially parallel to the rear face of the case 16. In doing so, the charged battery 58 is brought close enough to the case 16 that magnetic attraction pulls the battery 58 from the platform 78 into alignment with the recess 28 of the case 16 and then pulls the battery 58 into the recess 28 as shown in Figure 10, hence effecting electrical connection between the battery 58 and the phone 14 via the case 16.

When the charged battery 58 vacates the platform 78 to be pulled into the recess 28 of the case 16, this leaves clearance for the depleted battery 26 to fall further to the bottom of the battery path 50 and thereby to drop onto the inboard portion 68 of the base plate 72. Initially, though, the depleted battery 26 is still retained by the flange 64 on the wall 66 of the platform 78 even as the charged battery 58 is pulled into the recess 28 of the case 16. This ensures that the depleted battery 26 cannot interfere with movement of the charged battery 58 into the recess 28. In this respect, the pivoting action of the platform 78 pulls the flange 64 forward and so deepens the shoulder defined by the flange 64. Also, the upper end of the depleted battery 26 is still engaged by the tab 64 of the separator blade 82. However, when the newly-formed assembly 24 of the phone 14, case 16 and charged battery 58 is lifted off the platform 78 as shown in Figure 11 , the platform 78 is biased to pivot back to its rest position. This reduces the depth of the shoulder and so allows the depleted battery 26 to complete its downward journey along the battery path 50, reaching its final position resting on the inboard portion 68 of the base plate 72.

The assembly of the phone 14, case 16 and charged battery 58 can now be withdrawn from the housing 17 of the swapping unit 10 as shown in Figures 12 and 13. The plunger 74 then extends to effect charging contact 76 with the contacts 42 of the depleted battery 26 and to hold the depleted battery on the inboard portion 68 of the base plate 72. Also, as noted above, the blade 82 of the swapping mechanism 12, 60 pivots aside against the bias of its springs 52 to allow the lower portion of the assembly 24 to be withdrawn back along the insertion path 48 and out through the opening 46 in the housing 17.

As the depleted battery 26 moves down the battery path 50 relative to the charged battery 58, there may be some sliding contact between the batteries 26, 58. In that respect, the downward convergence between the charged battery 58 and the guide strip 56 can help to guide the lower end of the depleted battery 26 into final alignment with the inboard portion 68 of the base plate 72.

Many other variations are possible within the inventive concept. For example, when attached to the case 16, the outer battery 26 can be charged via the case 16. For this purpose, the case 16 has a wired or wireless power input. The internal battery of the phone 14 can also be charged via the case 16 in this way. Also, the battery swapping unit 10 could charge depleted batteries by hard wire or wirelessly

The battery swapping unit 10 could have a drive mechanism that acts on the battery 26 to drive movement of the battery 26 along the battery path 50. For example, driven rollers 57, bands or belts could be placed along the battery path 50 to engage and drive movement of the battery 26. Thus, the battery swapping unit 10 need not rely upon gravity to move the battery along the battery path 50. More generally, therefore, the battery swapping unit 10 can be used in any orientation. References in the foregoing description to positional or directional terms such as vertical, horizontal, upward and downward should therefore be interpreted as examples of orientation and direction that could change if the battery swapping unit 10 is oriented differently.

Optionally, data can also be conveyed from or to the phone 14 via the mutually-aligned contacts of the case 16 and the phone 14 or via a wireless data coupling between the case 16 and the phone 14 or between the battery swapping unit 10 and the phone 14. For example, the case 16 may have an onboard memory for holding data received from or to be transferred to the phone 14. The onboard memory of the case 16 could therefore serve as additional data storage capacity to supplement the internal memory of the phone 14. Data may also be transferred via the case 16, either from the phone 14 to an external recipient or to the phone 14 from an external source. The battery swapping unit 10 could also act as a data relay and/or as a data store for conveying or storing data received from the phone 14 or to be transferred to the phone 14, either via the case 16 or directly. For that purpose, the controller 18 of the unit 10 could comprise or be connected to a memory device within the unit 10.

Instead of contacts 42, 76, it would be possible to have a wireless power and/or data coupling between the case 16 and the phone 14, between the outer battery 26 and the case 16, between the battery swapping unit 10 and the outer battery 26, the case 16 or the phone 14 and/or between the case 16 and a power source external to the case 16.

The battery swapping unit 10 may contain a sanitising system that acts on the case 16 and/or on the battery 26 or batteries 26, 58 when they are within the housing 17 of the unit 10. The sanitising system may, for example, comprise ultra-violet lamps on one or both sides of the case path 80 and/or the battery path 50 that illuminate the interior of the housing 17 when the case 16 is present within the housing 17. The sanitising system may, for example, be activated when the case 16 enters the insertion path 48 or the case path 80 or encounters the reassembly mechanism.