Adapter socket for a rechargeable battery

An device with a standard automotive electrical accessory plug may be connected to a standard rechargeable battery for a cordless power tool with an electrical adapter. The electrical adapter has a socket for receiving the automotive accessory plug. The sleeve and center contact of the socket are each connected to respective conductive members, with ends thereof forming one or two electrical plugs. The electrical plugs make electrical contact with terminal contacts of the battery. The electrical plug(s) may be is used with a tower-type rechargeable cordless power tool battery and/or a slide-on-type rechargeable cordless power tool battery. The electrical adapter enables portable use of the device powered by the rechargeable battery, without remaining near another power source such as an automobile. The electrical adapter enables recharging of the battery using an alternate charging power source.

BACKGROUND

The field of the present disclosure and/or appended claims relates to rechargeable batteries and adapters therefor. In particular, adapter sockets are disclosed and/or claimed herein for use with rechargeable batteries.

A wide variety of batteries, connectors, cables, chargers, and adapters are available for powering electrical equipment of various sorts. Some of these are described in:

U.S. Pat. No. 4,647,139 entitled “Extension cord charging device for connecting tools and appliances to plug receptacle in vehicle” issued Mar. 3, 1987 to Yang;

U.S. Pat. No. 6,007,373 entitled “Apparatuses and methods for coupling DC power tools to external DC power sources” issued Dec. 28, 1999 to Chew;

A very common type of adapter makes possible the operation of electrical equipment using 12 V DC power supplied by an automobile battery and/or alternator (if the automobile engine is running). Such car adapters typically plug into the cigarette lighters nearly ubiquitously provided in automobiles, such cigarette lighters usually taking the form of a cylindrical socket with a conductive sleeve and a conductive center contact. The mating adapter plug typically includes a conductive outer shell for making contact with the socket sleeve and a center pin for making contact with the socket center contact. More recently, many auto manufacturers have begun to provide one or more such sockets in vehicles as dedicated power outlets, without also serving as cigarette lighters. While this type of adapter is very useful and finds application in a wide array of situations, the operating device is nevertheless constrained to remain within the proximity of the vehicle. It is often, but not always, the case that the electrical equipment operated in this way is intended to be operated in some other way as its usual mode of operation, and the car adapter is provided for occasions when that usual mode of operation is unavailable or depleted. For example, cell phones and laptop computers usually run off of their own dedicated batteries but may be operated using a car adapter as well.

A well-developed array of cordless power tools have been developed and are available in the professional and consumer marketplaces. Such cordless power tools offer obvious benefits for a user, who is no longer hampered or constrained by a corded connection to a power source while using the tool. These cordless power tools are powered by rechargeable batteries, and typically include a separate recharging unit for recharging the battery (the recharging unit typically being plugged into a household electrical outlet). Such cordless power tools are available for operating at several industry-standard battery voltages (including 24, 18, 14.4, 12, 9.6, 7.2, 4.8, 3.6, and 2.4 volts, although other voltages may be employed), and batteries tend to come in one of only a few industry-standard mechanical configurations for assembly/connection with the tools. Multiple batteries might be employed with one tool, with a first battery in use while the second is recharging. A single battery may also be swapped between different tools (at least those of the same manufacturer). Several adapters have been developed for operating these cordless tools connected to alternate power supplies (in corded fashion), presumably for those situations when a user may not wish to wait for the battery to charge. Such adapters may serve to operate the cordless tool connected to a household electrical outlet (in which case the adapter must include an AC-to-DC converter), to a car battery (in which case the adapter would typically include an adapter plug as described in the previous paragraph), directly to a battery charger (which is in turn typically connected to a household outlet and includes an AC-to-DC converter), or to some other suitable alternate power source.

While use of cordless power tools using alternative power sources has been implemented, use of batteries provided for those tools for powering other devices has not heretofore been contemplated. It would be desirable to enable use of such rechargeable cordless tool batteries (of which millions of units are already deployed and new units are readily available commercially) for portable powering of other devices. Many devices for which such a power source (i.e., a DC battery) would be suitable are already equipped with, or may be readily adapted for use with, an adapter for a car power socket (i.e., cigarette lighter). Use of a rechargeable cordless tool battery would enable portable operation of the devices away from a vehicle.

SUMMARY

A method for providing portable electrical power to an electrical device (the device having a device plug including a conductive portion of its outer surface and a center conductive pin) includes: connecting a first battery terminal contact to the conductive portion of the outer surface of the device plug with an electrical adapter; and connecting a second battery terminal contact to the center conductive pin of the device plug with the electrical adapter. The electrical adapter includes an adapter socket and a pair of electrically conductive members. The adapter socket includes a conductive sleeve connected to one conductive member and a conductive contact connected to the other conductive member. The sleeve forms a passage having an open end and is adapted to receive the device plug and establish electrical contact with the conductive portion of the outer surface of the device plug. The conductive contact (which is insulated from the sleeve) is positioned at the other end of the passage for establishing electrical contact with the center conductive pin of the device plug. Each conductive member has a substantially rigid elongated end thereof arranged in a substantially parallel spaced-apart arrangement with the elongated end of the other conductive member thereby forming an electrical plug. A first electrical plug is adapted for engaging the first and second battery terminal contacts and thereby providing electrical connections (i) between the conductive sleeve and the first battery terminal contact and (ii) between the conductive contact and the second battery terminal contact. The other ends of the conductive members may be similarly substantially rigid, elongated, and arranged to form a second electrical plug.

The adapter socket may be adapted to receive standard automotive electrical accessory plugs (including standard cigarette lighter automotive electrical accessory plugs). The first and second electrical plugs may be different widths for connecting to batteries of differing sizes. The conductive members may each be further provided with a screw terminal for enabling connection to other power sources, and the adapter may be further provided with an output voltage regulator, limiter, and or switch, and/or an output polarity indicator and/or switch. A housing may be provided for insulating the conductive members and the outer surface of the sleeve, and may comprise a polymeric material in which the conductive members and sleeve are embedded (except for the ends forming the electrical plugs) or a hollow housing from which the plugs protrude. The conductive member ends (forming the plug) may be adapted for engaging between and/or around the battery terminal contacts.

The electrical plug(s) may be adapted to provide electrical connections to standard rechargeable batteries for cordless power tools, either of the tower type or the slide-on type. After providing the electrical adapter to a user, the user is instructed to (i) disengage a rechargeable battery from a cordless power tool or battery charger, (ii) engage the electrical plug and the battery terminal contacts of the rechargeable battery, and (iii) plug an electronic device (with a standard automotive electrical accessory plug) into the adapter socket. The first and second electrical plugs of the electrical adapter may be adapted for engaging standard tower-type and/or slide-on-type rechargeable batteries for cordless power tools. The adapter may also be employed for connecting cordless power tool rechargeable batteries (including tower-type and slide-on-type) to an alternate charging power source.

Objects and advantages of the present invention may become apparent upon referring to the disclosed embodiments as illustrated in the drawings and disclosed in the following written description and/or claims.

DETAILED DESCRIPTION OF EMBODIMENTS

FIGS. 1A–1Eand2A–2B illustrate an electrical adapter generally designated100and including an adapter socket110and electrical plugs120and130. A schematic circuit diagram appears inFIG. 6. Adapter socket110includes a conductive sleeve112and a conductive contact114. Sleeve112forms an open-ended passage for receiving a device plug of an electrical device to be connected to a power source. An insulating housing101surrounds sleeve112and substantially insulates its outer surface from a use environment, and also serves to insulate sleeve112and contact114from one another. Housing101may comprise a polymeric material (such as molded urethane, for example; other suitable polymeric materials may be equivalently employed) in which are embedded sleeve112, contact114, and other elements of the electrical adapter. Housing101may alternatively comprise any suitably arranged and adapted housing structure, including a hollow or shell-type housing, for substantially insulating the outer surface of sleeve112, as well as other elements of the adapter, from a use environment.

Sleeve112is electrically connected to a conductive member102within housing101, while contact114is electrically connected to another conductive member104within housing101. Substantially rigid elongated ends122and124of conductive members102and104, respectively, protrude from housing101in a substantially parallel spaced-apart arrangement to form an electrical plug120. The electrical plug120may engage a pair of battery terminal contacts, and the electrical adapter100may therefore serve to provide electrical connections between one battery terminal contact and sleeve112and between the other battery terminal contact and contact114. An electrical device supplied with a device plug having an outer surface including a conductive portion thereof, and center conductive pin, may be inserted into adapter socket110to provide electrical contact with sleeve112and contact114, respectively, thereby enabling the electrical device to obtain power from the battery.

Conductive members102and104may be each provided with substantially rigid second ends132and134, respectively, which protrude from housing101in a substantially parallel spaced-apart arrangement to form electrical plug130. Electrical plug130may engage battery terminal contacts in a manner similar to that described in the preceding paragraph to provide a electrical power to an electrical device from the battery. While remaining within the scope of the present disclosure and/or appended claims, additional electrical plugs may be formed in a similar manner on electrical adapter100.

Electrical adapter100and adapter socket110may be adapted for receiving a standard automotive electrical accessory plug, including plugs designed for connecting through an automotive cigarette lighter as well as through a dedicated automotive power outlet. Automotive electrical systems typical operate at about 12 V DC, although there may be variation in the voltage (intended and/or unintended). Many electrical devices, particularly portable electrical devices, include plugs and/or adapters for connecting to such automotive power outlets. Such devices may include those for which the automotive power outlet is the intended primary power source, and those devices where the automotive power outlet is a secondary or auxiliary power source (examples of this latter category may include, but are not limited to, mobile phones, portable or laptop computers, chargers for such devices, and so on). Operation of such devices still then requires the presence of a vehicle as a power source. An electrical adapter as disclosed herein enables use of such devices (with their automotive power outlet plugs) with portable batteries of a variety of types, and operation of the electrical devices away from the vehicle. Rechargeable batteries for cordless power tools are highly portable, widely deployed, and widely available, and are therefore a suitable power source for portable powering of an electrical device using an electrical adapter according to the present disclosure and/or appended claims.

Cordless power tool batteries come in a variety of mechanical and electrical configurations. An electrical adapter100may be adapted to accommodate such variation. For example, electrical plugs120and130may differ in size for accommodating batteries of differing sizes. Protruding ends122/124and/or132/134may be resiliently biased against lateral movement, while allowing some degree of such movement, to accommodate differences in battery size and/or terminal contact arrangement. Such resilient biasing may be provided by the resiliency of the conductive material (presumably a metal conductor) as it forms ends122/124and/or132/134, or housing101may be adapted for such resilient biasing (by including resilient gaskets or grommets where the ends pass through a wall of a hollow housing, or by using a resilient polymeric embedding material, or by other suitable means). Such resilient biasing may also serve to enhance the integrity of electrical contact established between ends122/124and/or132/134and corresponding battery terminal contacts. For example, ends122/124may be resiliently biased against movement apart, and the battery terminal contacts (and perhaps a portion of the battery as well) may be inserted between the ends122/124. Resilient biasing of the ends122/124serves compress the battery terminal contacts between the ends122/124and to thereby secure engagement of electrical plug120with the battery terminal contacts. For another example, ends132/134may be resiliently biased against movement toward one another, and they may be inserted between spaced-apart battery terminal contacts. Resilient biasing of the ends132/134allows compression thereof between the battery terminal contacts and to thereby secure the engagement of electrical plug130with the battery terminal contacts.

Such adaptations of electrical plugs120and/or130of adapter100may serve to enable use of the adapter with many commonly-available rechargeable cordless power tool batteries, including tower-type batteries, slide-on-type batteries, and other types of rechargeable cordless power tool batteries. FIGS.3A/3B/3C illustrate a procedure for connecting an electrical device with an automotive electrical accessory plug10to a tower-type cordless tool rechargeable battery20using electrical adapter100(through socket110and electrical plug120). FIGS.4A/4B/4C illustrate a procedure for connecting an electrical device with an automotive electrical accessory plug10to a slide-on-type cordless tool rechargeable battery30using electrical adapter100(through socket110and electrical plug130).FIG. 5shows electrical adapter100engaged with automotive electrical accessory plug10through socket110and with a rechargeable battery40of yet another type. Such uses are exemplary only, and use of adapter100for connecting an electrical device to any standard rechargeable cordless power tool battery, or other suitable battery, shall fall within the scope of the present disclosure and/or appended claims. In particular, each of plugs120and130may be used with the corresponding ends between battery terminal contacts or around battery terminal contacts, with or without resilient biasing as described hereinabove.

Many DC-driven electrical devices, including those which may be powered from an automotive power outlet, are sensitive to the polarity of the supplied voltage. Such sensitivity may range from non-optimal operation with the wrong polarity to damage to or destruction of the electrical device operated with the wrong polarity. Standard automotive electrical power outlets and standard automotive electrical accessory plugs are designed to eliminate this issue, with the sleeve/outer surface being at ground potential and the center pin/center contact being held at about 12 V. Use of an electrical adapter100offers an opportunity to connect an electrical device to its power source with the wrong polarity. Some rechargeable cordless power tool batteries may be provided with mechanical alignment or registering members for facilitating proper assembly with and connection to the cordless power tool. An embodiment of electrical adapter100may be provided with corresponding alignment/registering members for engaging such members on a particular cordless tool battery type. Another embodiment of electrical adapter100may be provided with a polarity indicator103for informing the user that the polarity is correct. For example, a diode and light source (and perhaps also current-limiting a resistor) may be connected in series between conductive members so that the bulb lights up only when the contact114(and conductive member104) is at a positive voltage relative to shell112(and conductive member102). A light-emitting diode (LED) connected with the appropriate polarity (perhaps along with other suitable circuit elements) may similarly be arranged to light up only when the polarity across contacts114and shell112is correct (FIG. 7). Other suitable indicators may be equivalently employed. A fuse in series with a diode (and perhaps other circuit elements) may provide a more drastic degree of polarity protection. An embodiment of electrical adapter100may be provided with a switch105for enabling user selection of the output voltage polarity without disconnecting and reconnecting the adapter from the battery (FIG. 8). Such a polarity switch may be used to provide the correct polarity even if the adapter/battery are not suitable for reversing the connection (FIGS.4A/4B/4C for example).

The operating voltages of standard rechargeable may range from 24 V (or more) to 2.4 V (or less). Automotive power outlets typical provide around 12 V, although there may be variations (intended and/or unintended) in the voltage provided. Use of an embodiment of electrical adapter100may therefore be restricted to use with 12-volt cordless power tool batteries. In an embodiment of electrical adapter100(FIG. 9), a voltage limiter106of any suitable type (such as a Zener diode, for example; any other suitable voltage limiter may be equivalently employed) may be provided connecting conductive member102and104for limiting the voltage across electrical plug120and/or130to around 12 V (or to some other desired nominal output voltage). Such a voltage limiter may therefore protect 12-volt electrical devices during use with higher-voltage cordless power tool batteries, but may or may not enable their operation with lower-voltage cordless tool batteries (depending on the nature of the device). In another embodiment of electrical adapter100(FIGS. 10 and 11), connections from conductive members102and104to sleeve112and contact114, respectively, may be made through a DC-to-DC voltage regulator108of any suitable type (which may include an integrated circuit designed for providing such functionality). Such a regulator may therefore enable use of 12-volt (or other desired nominal operating voltage) electrical devices powered by cordless power tool batteries of a wide range of voltages. Voltage regulator108may be adapted for providing a single nominal output voltage (12 V, for example;FIG. 10), or may be adapted for enabling user selection of an output voltage using a multi-position switch109, for example (FIG. 11).

In order to enable any standard rechargeable cordless power tool battery to be used with electrical equipment lacking a standard automotive electrical accessory plug or compatible variant thereof, screw terminals142and144may be provided protruding from housing101and connected to conductive102and104, respectively.

Electrical adapters as disclosed and/or claimed herein may be provided to users in a variety of ways, including retail and/or wholesale sales. The user may be instructed to: (i) disengage a standard rechargeable battery from a cordless power tool or charger; (ii) engage an electrical plug of the adapter with the terminal contacts of the battery; and (iii) plug the electrical device (using its automotive-type plug) into the socket of the electrical adapter. The user may be further instructed to check polarity, select polarity, select output voltage, and so forth, if applicable.

In addition to providing power from a battery to an electrical device having an automotive electrical accessory plug, an electrical adapter as disclosed and/or claimed herein may be employed for charging a rechargeable battery as well. The electrical adapter may be connected to a charging power source (such as a car battery, an automotive power outlet or cigarette lighter, a solar panel, an AC adapter plugged into a household outlet, and so on). The battery to be charged is connected to the electrical adapter using an electrical plug of the adapter. The charging power source may be connected to the screw terminals of the electrical adapter, or into the socket of the electrical adapter if the charging power source has a compatible automotive accessory type plug.

It is intended that modifications to the disclosed embodiments may be made without departing from inventive concepts disclosed and/or claimed herein.