Patent Description:
Battery packs are often used in portable electronic devices and power tools, such that these devices and tools may be used in environments without available fixing power. For example, the power tool manufacturers often produce battery packs that are compatible with power tools and may be used in different types of power tools, such as electric drills, hammers, electric screwdrivers, corner grinders, etc. The battery pack usually includes a plurality of individual batteries or say battery cells mounted in the housing. Through a mechanical locking structure configured on the housing of the battery pack, the user may easily mount the entire battery pack to the power tool, or remove it from the power tool.

However, traditional battery packs are often manufactured in the factory to be immediately usable. That is, before the battery pack is shipped or sold, the battery pack has been fully assembled and is ready for use. When the battery pack is received, the end user may immediately insert the battery pack into the electronic device to begin using the electronic device. The battery pack manufactured in this way is undoubtedly convenient for users since there is no additional setup procedure on the client side before starting to use the battery pack. However, on the other hand, the problem of the battery pack is that once it is manufactured in the factory, the battery pack may start self-discharging, ultimately causing power consumption of the initial energy in the battery pack and reducing the battery lifetime. Additionally, in the transport regulation of many countries, the battery capacity is also prescribed to be not exceeding a certain standard, otherwise it may lead to the risk of accident, such as explosion during transportation, etc. An entire battery pack may easily have a capacity which exceeds such standards.

<NPL>, describes a battery holder comprising a housing and an ON/OFF switch.

Accordingly, embodiments of the present invention provide a battery pack, which overcomes or at least alleviates the above technical problem.

One aspect of the present invention is to provide a battery pack, which includes: a housing; a frame disposed within the housing, two or more cells mounted to the frame, and interface terminals configured to connect the two or more cells to an external device. The two or more cells are connected with each other through a configurable connector comprising connector terminals, different from the interface terminals. The connector terminals are suitable to connect or disconnect an internal circuit comprising an electrical connection between the two or more cells. The configurable connector includes a user contactable switch located on an outer surface of the housing. The user contactable switch is configured to move within a plane parallel to the outer surface, such that the contactable connector is switched between a first state and a second state. In the first state, the electrical connection exists between the two or more cells; in the second state, the electrical connection does not exist between the two or more cells.

Preferably, the configurable connector includes two connector terminals and an intermediate conductor simultaneously contacted with or separated from the two connector terminals. The intermediate conductor is fixed to the user contactable switch. The connector terminals are respectively connected to one of the two or more cells. When the intermediate conductor is not contacted with the connector terminals, the electrical connection does not exist between the connector terminals, such that the configurable connector is at the second state. When the intermediate conductor is contacted with the connector terminals, the connector terminals are connected with each other through the intermediate conductor, such that the configurable connector is at the first state.

More preferably, the two connector terminals are two metal pins configured to be arranged parallel to each other. The metal pins are elastic. The intermediate conductor includes a metal sheet capable of being removably inserted between the metal pins and simultaneously contacted with the metal pins.

In one variant embodiment, the user contactable switch further includes an indicator. The indicator is aligned with different signs on the outer surface as the movement of the user contactable switch, so as to indicate a connection state of the two or more cells.

In another variant embodiment, the battery pack further includes a circuit board. The two connector terminals of the configurable connector are fixed on the circuit board.

In another variant embodiment, the intermediate conductor is biased to a position separated from the two connector terminals through a biasing element.

In another variant embodiment, the battery pack includes a plurality of configurable connectors; the plurality of configurable connectors has a plurality of corresponding intermediate conductors, and the plurality of intermediate conductors is connected to the user contactable switch.

Therefore, the present invention provides many advantages. When a battery pack according to the present invention is manufactured at a factory, it is not in a usable state. The non-use state continues, for example, during the storage process of the store, during the shipping process, during the sale of the battery pack in the store, and even after the user finally purchases the power tool with the suitable battery pack or separately purchases the battery pack, but he/she does not open the packaging of the battery pack and the battery pack is left idle. At the time the user switches the sliding switch located on the housing so that the electrical connection between the cells insides the battery pack changes to a connecting state from a disconnecting state, the battery pack enters the usable state, the circuit inside the entire battery pack is conducted and the battery pack becomes ready for use. Therefore, before the user operates the sliding switch on the housing of the battery pack, the circuit inside the battery pack is actually not connected, or "turned off", such that the self-discharge effect due to the connection of the plurality of cells is eliminated. On the other hand, the battery pack of the present invention is easy and convenient for the user to use, since the user only needs to slide the switch before using it, without having to touch the internal components of the battery pack or to perform any complicated procedure. This will not cause any difficulty for the average users.

A further advantage of the present invention is that for the user, the only exposed parts of the configurable connector is the user contactable switch, and other parts of the configurable connector, and in particular the metal pins and intermediate conductors which have electricity are located inside the housing of the battery pack. In this way, the user will not has the risk of suffering an electric shock or accidentally causing a short circuit inside the battery pack since outside objects such as fingers may not reach the space inside the housing of the battery pack. Therefore, the safety of the battery pack is greatly guaranteed. Additionally, since the entire configurable connector is integrated on the battery pack and does not contain any removable or external components, it is convenient for the user and the user does not need to worry about that the battery pack is inoperable if one or more components are missing for example due to the transportation of the battery pack. Similarly, the user does also not worry about that a component is lost or may not found when the battery pack is configured to the non-use state (such as idle) by the user itself.

By referring to the remainder of the specification and the drawings, it is possible to further understand the performance and advantages of the present invention. The same components in the drawings are indicated with the same numerals. In some cases, the sub sign is placed after a reference number and a hyphen to represent one of many similar components. When a reference number is mentioned but not specifically stated an existing sub sign, it refers to all similar components.

Embodiments of the present invention use a sliding switch to promote a reconfigurable process of the connecting and disconnecting of the internal circuit of the battery pack. Other benefits and advantages provided by various embodiments of the present invention may be easily understood from the following description.

Please refer to <FIG>, according to a first embodiment of the present invention, a battery pack <NUM> is a power tool battery pack, which may be mounted to or removed from one or more power tool bodies (not shown). Alternatively, the battery pack <NUM> may also be independently mounted on a battery charger (not shown) for charging. The battery pack <NUM> has a substantially cuboid shape, and a top surface <NUM> of the housing thereof is shown in <FIG> Herein, the top surface <NUM> means that an outer surface of the battery pack <NUM> connected to more outer components. Specifically, four signs <NUM> of four interface terminals (not shown) corresponding to the battery pack <NUM> is shown in <FIG>. These interface terminal may be contacted with the corresponding electrical terminals of the above-mentioned power tool or charger and transmit electric power or signals. Although not shown in <FIG>, in the direction from top to bottom in the figure, the four interface terminals correspond to four signs <NUM>, i.e., "+", "T2", "T1", "-". Wherein "+" and "-" are power terminals for outputting power, and "T2" and "T1" are terminals for signal or control. These interface terminals are actually located under the covering plate <NUM> of the top surface <NUM>, therefore allowing corresponding terminals of the external chargers or power tools to be inserted under the covering plate <NUM> along a direction parallel to the paper plane in <FIG> and be connected to the interface terminal of the battery pack <NUM>.

In addition, there is a user contactable switch on the top surface <NUM>, in particular a sliding switch <NUM>. The sliding switch <NUM> has a substantially sheet-like shape, and is partially exposed to an opening <NUM> on the top surface <NUM>. On the surface of the sliding switch <NUM>, a protruding rib <NUM> is configured as a portion for pulling the sliding switch <NUM> by the user, and a triangle <NUM> is configured as an indicator. The protruding rib <NUM> may be moved left and right between the two positions in a horizontal plane (i.e., parallel to the plane of a circuit board <NUM> and the top surface <NUM>). The triangle <NUM> is respectively aligned with a word ON <NUM> and a word OFF <NUM> labeled on the top surface <NUM> with the movement of the sliding switch <NUM>. The words ON <NUM> and OFF <NUM> may be printed directly on the top surface <NUM> or as an independent sign, for example, to be adhered to the top surface <NUM>. The protruding rib <NUM> may be pulled directly by the user, thereby causing the sliding switch <NUM> to move together.

Refers to <FIG>, an interior of the battery pack <NUM> has a plurality of cells <NUM> connected with each other, and each of the plurality of the cells <NUM> has a substantially cylindrical shape. Different cells <NUM> are electrically connected through connecting strips <NUM> made of the metal. However, it should be noted that not all of the cells <NUM> are connected with each other through the connecting strips <NUM>. On the contrary, the connecting strips <NUM> are only used to connect to a part of cells <NUM>. For example, all cells <NUM> are divided into some groups (not shown). The cells in each group are permanently connected through the connecting strips and the electrical connection does not permanently exist between the different groups. On the contrary, the connection between the group and the group needs to be achieved with a configurable connector, which will be explained in more details below.

A circuit board <NUM> covers the top of all cells <NUM>, and the circuit board <NUM> has a length and a width which are approximately equal to the length and width of the entire battery pack <NUM>. Four interface terminals <NUM> as mentioned above are fixed on the circuit board <NUM>, and these terminals <NUM> extend upwardly and horizontally from the circuit board <NUM> in a L-shape.

Some connector terminals <NUM> and a switching terminal <NUM> are also fixed on the circuit board <NUM>. These connector terminals <NUM> are parts of the configurable connector in this embodiment. Different from the interface terminal <NUM>, the connector terminals <NUM> are not used to connect to external devices, but rather are used to disconnect or connect internal circuits of the battery pack <NUM>. The above groups of different unit cells <NUM> are connected to the connector terminals <NUM> through a connecting strip <NUM>.

<FIG> shows a structure of one above-mentioned connector terminal <NUM>. Each terminal <NUM> includes two pins <NUM> arranged parallel to each other and spaced apart from each other. Each pin <NUM> has a substantially hook-like shape. A bending of the hook shape occurs in a horizontal plane. A bending portion <NUM> near the end of the hook is the closest portion between the two pins <NUM>. However, in normal cases, they are not contacted to enable electrical connection, but there is a certain gap between the two pins <NUM>. Each pin <NUM> is connected to the above-mentioned connecting strip <NUM> through the adjacent pin thereof <NUM>. The pins <NUM> are soldered to the circuit board <NUM>. The connection of the pin <NUM> and the pin <NUM> are located under the circuit board <NUM>, and that it why the connection is not shown in <FIG>. Additionally, the pin <NUM> is elastic because it is formed by bending a thin metal sheet. The structure of the switching terminal <NUM> and the structure of the connector terminal <NUM> are identical, and they are just different in intended use.

Additionally, although not shown in <FIG>, a plurality of intermediate conductors is fixedly connected under the sheet-like sliding switch <NUM>, and in particular a plurality of metal contacts. With the movement of the sliding switching <NUM>, these metal contacts also move left and right in the horizontal plane, so as to be selectively contacted with or departed from the plurality of terminals <NUM> at the same time. The sliding switch <NUM> also has a metal contact to contact with or detach from the terminal <NUM>.

<FIG> is an internal circuit diagram of a battery pack according to an embodiment of the present invention. A plurality of cells (not shown) is divided into different groups <NUM>, and the total number of the groups <NUM> is ten, as shown in <FIG>. Some of the groups <NUM> are permanently electrically connected through the above-mentioned connecting strip <NUM>, and some of the groups <NUM> are connected to each other through configurable connectors <NUM>. The configurable connectors <NUM> include the above-mentioned intermediate conductors, connector terminals, etc. Output terminals of the internal circuit of the entire battery pack are respectively a negative electrode <NUM> and a positive electrode <NUM>, and the negative electrode <NUM> and the positive electrode <NUM> are used to connect to external devices, such as battery chargers or power tools, etc. Since the configurable connectors <NUM> may selectively be at a connecting or a disconnecting state of a electric connection, the entire circuit as shown in <FIG> is formed as a closed loop in the connection state, such that the power tool connected to the battery pack may obtain a current outputted by the battery pack, and a charger connected to the battery pack may input the circuit to the battery pack. On the contrary, the entire circuit does not form a closed loop in the disconnecting state, such that the power tool connected to the battery pack may not obtain the current outputted by the battery pack, and the charger connected to the battery pack may not input the circuit to the battery pack.

After the structure of the battery pack in <FIG> is described, the using method of the battery pack <NUM> will be described next with reference to <FIG>. In <FIG>, it is shown that the appearance of the battery pack <NUM> is in states such as storage, transportation, out-of-factory, etc., and the configurable connector is in a second state. Specifically, under the second state, the sliding switch <NUM> is located at a rightward position (in the width direction of the battery pack <NUM>) between the two positions where it may reach. Therefore, at this time, the triangle <NUM> points to the words OFF <NUM>, which prompts the user that the battery is in a non-operating state at this time. <FIG> shows an internal state of the configurable connector in this state. At this time, the metal contact <NUM> arranged under the sliding switch <NUM> does not contact with the pin <NUM> of the corresponding connector terminal <NUM> thereof and is departed therefrom with a certain distance. In this way, the intermediate conductor does not exist between the two opposite pins <NUM>, such that the electrical connection of the configurable connector is in the disconnected state. Therefore, the internal circuit in the entire battery cell is not closedat this time.

When the user finally wants to place the battery pack <NUM> in a power tool (not shown) to use or place it a charger (not shown) to charge the battery pack <NUM>, then he/she needs to change the state of the configurable connector. Specifically, for the battery pack <NUM> as shown in <FIG>, the user needs to use the finger to pull the protruding rib <NUM> to the left, such that the sliding switch <NUM> may also move leftward to the leftward position at the same time. The appearance of the battery pack <NUM> after pulling is shown in <FIG>, where the triangle <NUM> points to ON <NUM>. At this time, the configurable connector is in the first state.

<FIG> shows the internal state of the configurable connector in the first state. During the above pulling process, the metal contact <NUM> arranged under the sliding switch <NUM> may be moved toward the pin <NUM> of the corresponding connector terminal <NUM> thereof (in the downward direction in <FIG>) with the leftward movement of the sliding switch <NUM>. The gap existed between the pins <NUM> is smaller than the width of the metal contact <NUM>, and it is insufficient to accommodate the metal contacts <NUM>. However, when the metal contact <NUM> moves and are forced to enter into the gap, the metal contact <NUM> forces the two parallel pins <NUM> to move apart from each other since the pins <NUM> are elastic. The separated pin <NUM> may generate corresponding restoring force acting on the metal contact <NUM>, such that the metal contact <NUM> is maintained in close contact with the pin <NUM> and they do not separate easily. In this way, the intermediate conductor formed of the metal contact exists between the two opposite pins <NUM>, such that the electrical connection of the configurable connector is at the connection state. Therefore, the internal circuit in the entire battery pack <NUM> is fully closed at this time, such that the charging and the discharging of the battery pack <NUM> is possible.

Claim 1:
A battery pack (<NUM>), comprising:
a housing;
a frame disposed inside the housing;
two or more cells (<NUM>) mounted to the frame; and
interface terminals (<NUM>) configured to connect the two or more cells (<NUM>) to an external device,
characterized in that the two or more cells are connected with each other through a configurable connector (<NUM>) comprising connector terminals (<NUM>), different from the interface terminals (<NUM>), wherein the connector terminals (<NUM>) are suitable to connect or disconnect an internal circuit comprising an electrical connection between the two or more cells;
wherein the configurable connector (<NUM>) comprises a user contactable switch (<NUM>) located on an outer surface (<NUM>) of the housing ; the user contactable switch (<NUM>) configured to move within a plane parallel to the outer surface, such that the configurable connector (<NUM>) is switched between a first state and a second state; in the first state, the electrical connection existing between the two or more cells (<NUM>); in the second state, the electrical connection not existing between the two or more cells (<NUM>).