HAND-HELD POWER TOOL RECHARGEABLE BATTERY

BACKGROUND INFORMATION

Various hand-held power tool rechargeable batteries which include at least one first rechargeable battery cell and at least one inductive charging unit which includes at least one inductive charging coil for charging the at least one rechargeable battery cell have already been provided.

SUMMARY

The present invention is directed to a hand-held power tool rechargeable battery which includes at least one first rechargeable battery cell and at least one inductive charging unit which includes at least one inductive charging coil for charging the at least one first rechargeable battery cell.

It is provided that the at least one first rechargeable battery cell has a main direction of extension oriented at least essentially perpendicularly with respect to a coil plane of the inductive charging unit.

A “hand-held power tool rechargeable battery” is understood in particular to mean a device which includes at least one rechargeable battery cell unit, and units for charging and discharging the energy storage unit, which is provided for supplying a hand-held power tool with current. The hand-held power tool rechargeable battery is preferably accommodated in a receiving space of the hand-held power tool or detachably fastened to the hand-held power tool. Alternatively, it is also conceivable for the hand-held power tool rechargeable battery to be provided separately from the hand-held power tool and to be electrically connected via a power line, for example a cable. In the present context, a “hand-held power tool” is understood in particular to mean an electrical device which is hand-operated by a user, such as in particular a power drill, a drill hammer, a saw, a plane, a screwdriver, a milling tool, a grinder, an angle grinder, and/or a multifunctional tool or a garden tool such as a hedge trimmer, shrub shears, and/or grass shears. Alternatively, the hand-held power tool rechargeable battery may also be used in some other hand-operated unit, for example a measuring device. A “rechargeable battery cell unit” is understood in particular to mean a rechargeable energy storage unit which includes at least one rechargeable battery cell which is provided for storing energy for generating an electric current, and charging by introducing a charging current. In particular, the rechargeable battery cell unit may include at least one rechargeable battery cell block in which multiple rechargeable battery cells are connected in series. The rechargeable battery cell unit may also include multiple rechargeable battery cell blocks, each with an identical number of rechargeable battery cells which are provided for successively supplying the hand-held power tool with current, so that the hand-held power tool is supplied with current for a longer period of time than would be possible with a single rechargeable battery cell block. A “rechargeable battery cell” is understood in particular to mean a unit which is provided for electrochemically storing electrical energy with the aid of a reversible reaction. The rechargeable battery cell may be formed, for example, by a lead rechargeable battery cell, an NiCd rechargeable battery cell, or an NiMH rechargeable battery cell, but preferably by a lithium-based rechargeable battery cell. The rechargeable battery cell may be formed by rechargeable battery cells having different nominal voltages, for example nominal voltages of 1.2 V, 1.5 V, or 3.6 V. The rechargeable battery cells preferably have a cylindrical shape. The hand-held power tool rechargeable battery may include multiple rechargeable battery cells which are connected in series in order to achieve a higher total voltage of the hand-held power tool rechargeable battery. For example, the hand-held power tool rechargeable battery may include one rechargeable battery cell having a voltage of 3.6 V, two rechargeable battery cells, connected in series, having a voltage of 3.6 V each for a total voltage of the hand-held power tool rechargeable battery of 7.2 V, or three rechargeable battery cells, connected in series, having a voltage of 3.6 V each for a total voltage of the hand-held power tool rechargeable battery of 10.8 V. In addition, the hand-held power tool rechargeable battery may include additional rechargeable battery cells which are connected in parallel to the at least one first rechargeable battery cell and which are provided for supplying a hand-held power tool with current after a discharge of the at least one first rechargeable battery cell, so that a capacity of the hand-held power tool rechargeable battery is effectively increased. In a series connection of multiple rechargeable battery cells for generating a higher total voltage, multiple additional rechargeable battery cells may be appropriately connected in parallel to one another and in series to form the series connection in order to increase the capacity. In a series connection of three rechargeable battery cells, these are preferably arranged in a triangular form in a plane perpendicular to a main extension of the three rechargeable battery cells. An “inductive charging unit” is understood in particular to mean a unit for charging the rechargeable battery cell unit, which receives a charging current via induction and which includes at least one inductive charging coil and charging electronics. The inductive charging unit preferably also includes at least one coil core unit for increasing an inductance of the at least one inductive charging coil. The inductive charging unit advantageously includes a coil carrier which positions the inductive charging coil relative to the coil core. The inductive charging unit is advantageously also provided for communicating with an inductive charging unit of the inductive charging unit device for controlling charging, and in particular for foreign object recognition. In the present context, an “inductive charging coil” is understood in particular to mean a coil which includes at least one winding made of an electrically conductive material, and which is provided for receiving, in at least one operating state, electrical energy which is transmitted by an inductive charging coil of an inductive charging unit and supplying it to a rechargeable battery cell via charging electronics. In particular, the inductive charging coil is provided for converting an electromagnetic alternating field into an alternating electric current, and/or vice versa. The alternating field preferably has a frequency of 10 kHz-500 kHz, particularly preferably 100 kHz-120 kHz. In particular, the direction is provided perpendicularly with respect to the coil plane, in parallel to a winding axis of the inductive charging coil. “Charging electronics” is understood in particular to mean an electronic unit which is provided for controlling charging of rechargeable battery cells, and which in particular includes electronic elements for a voltage transformation.

A “main direction of extension” is understood in particular to mean a direction in parallel to an axis of symmetry along which the rechargeable battery cell has a maximum extension. A “coil plane” is understood in particular to mean a plane in which windings of the inductive charging coil extend. In particular, the coil plane extends perpendicularly with respect to a winding axis of the inductive charging coil. The phrase “the main direction of extension of the rechargeable battery cell is oriented at least essentially perpendicularly with respect to a coil plane of the inductive charging unit” is understood in particular to mean that an angle between the coil plane and the main direction of extension differs from 90 degrees by 30 degrees maximum, advantageously by 20 degrees maximum, preferably by 10 degrees maximum, and particularly preferably by 5 degrees maximum. In particular, the main direction of extension may extend at a right angle to the coil plane.

Due to the design according to the present invention, in particular a hand-held power tool rechargeable battery having a particularly compact design with a preferably small cross-sectional diameter may be achieved, which with regard to an extension of the rechargeable battery cell in a plane in parallel to the coil plane has a larger diameter of an inductive charging coil, via which rapid charging of the rechargeable battery due to a high field intensity is made possible.

In one refinement of the present invention, it is provided that the hand-held power tool rechargeable battery includes at least one additional rechargeable battery cell having a main direction of extension oriented at least essentially in parallel to the coil plane of the inductive charging unit. The at least one additional rechargeable battery cell may be connected to the at least one first rechargeable battery cell in a series connection in order to achieve a higher total voltage of the hand-held power tool rechargeable battery than with only the first rechargeable battery cell alone, or may be connected in parallel to the at least one first rechargeable battery cell and be provided for supplying the hand-held power tool with current after discharge of the at least one first rechargeable battery cell. In addition, multiple first rechargeable battery cells may be connected to one another in series, and multiple additional rechargeable battery cells may be connected to one another in series and in parallel to the multiple first rechargeable battery cells. The phrase “the main direction of extension of the at least one additional rechargeable battery cell is oriented at least essentially in parallel to a coil plane of the inductive charging unit” is understood in particular to mean that an angle between the coil plane and the main direction of extension differs from 0 degrees by 30 degrees maximum, advantageously by 20 degrees maximum, preferably by 10 degrees maximum, and particularly preferably by 5 degrees maximum. In particular, the main direction of extension may extend in a plane in parallel to the coil plane. In particular, a hand-held power tool rechargeable battery may be achieved which compactly stores a plurality of rechargeable battery cells.

Furthermore, it is provided that the at least one additional rechargeable battery cell is situated between the at least one first rechargeable battery cell and the inductive charging coil. The phrase “the at least one additional rechargeable battery cell is situated between the at least one first rechargeable battery cell and the inductive charging unit coil” is understood in particular to mean that all planes in parallel to the coil plane, which extend through the at least one additional rechargeable battery cell, do not intersect with the at least one first rechargeable battery cell. In particular, a compact design of the hand-held power tool rechargeable battery may be achieved.

In addition, it is provided that a diameter of the inductive charging coil is greater than a main length of extension of the at least one additional rechargeable battery cell. A “main length of extension” is understood in particular to mean a length along the main direction of extension. In particular, a compact hand-held power tool rechargeable battery having a short charging time for charging the at least one additional rechargeable battery cell may be achieved.

Moreover, it is provided that the hand-held power tool rechargeable battery includes a rechargeable battery housing having a coil receiving area for accommodating the inductive charging coil and which at least partially forms a form-fit element. A “rechargeable battery housing” is understood in particular to mean an assembly which includes at least one housing component which with outer walls at least partially delimits the hand-held power tool rechargeable battery with respect to the surroundings, and which in particular is provided for protecting the inductive charging unit and the rechargeable battery cells from the surroundings in an installed and/or uninstalled state on the hand-held power tool, and to avoid damage and/or soiling. In particular, the rechargeable battery housing defines a shape and a size of the hand-held power tool rechargeable battery. The rechargeable battery housing preferably includes fastening devices for fastening the hand-held power tool rechargeable battery to the hand-held power tool. The rechargeable battery housing advantageously has contact recesses via which electrical contact between the hand-held power tool and the at least one first rechargeable battery cell may be established. In particular, the rechargeable battery housing may have a completely or only partially closed design. In a partially closed design of the rechargeable battery housing, an area of the hand-held power tool rechargeable battery which is clear of the rechargeable battery housing may be provided situated within a housing of the hand-held power tool in a state in which the hand-held power tool rechargeable battery is mounted on a hand-held power tool. A “coil receiving area” is understood in particular to mean an area of the rechargeable battery housing which at least partially encloses a space within which the inductive charging coil of the inductive charging unit is situated. The coil receiving area preferably has an extension which in at least one direction is different from extensions of rechargeable battery housing areas which enclose the rechargeable battery cells. The phrase “the coil receiving area at least partially forms a form-fit element” is understood in particular to mean that the coil receiving area of the rechargeable battery housing protrudes or is recessed with respect to other areas of the rechargeable battery housing on at least one side face, preferably at least two side faces, of the rechargeable battery housing, so that for establishing a form-fit connection, a corresponding form-fit element of another unit, for example an inductive charging unit or the hand-held power tool, engages with a form-fit recess which is at least partially formed by the coil receiving area, or encloses a form-fit projection which is at least partially formed by the coil receiving area. The coil receiving area is particularly preferably designed in such a way that it protrudes with respect to adjacent areas of the rechargeable battery housing at the side faces on at least two side faces of the rechargeable battery housing and forms a form-fit projection. In particular, the form-fit element is provided for effectuating a form-fit fastening to an inductive charging unit during a charging phase in order to achieve efficient energy transmission. In particular, the rechargeable battery housing includes a rechargeable battery cell receiving area for accommodating the at least one rechargeable battery cell, which is recessed relative to the coil receiving area. A “rechargeable battery cell receiving area” is understood in particular to mean an area of the rechargeable battery housing which at least partially encloses a space within which the at least one rechargeable battery cell and/or the at least one additional rechargeable battery cell is/are situated. The phrase “the rechargeable battery cell receiving area is recessed relative to the coil receiving area” is understood in particular to mean that on at least one side face, preferably on at least two side faces, of the rechargeable battery housing, the rechargeable battery cell receiving area has a smaller extension in a direction of a perpendicular to the side face than does the coil receiving area. In particular, a compact hand-held power tool rechargeable battery may be achieved for simple fastening to an inductive charging unit or a hand-held power tool, while dispensing with separate external fastening elements. In particular, an advantageously small transverse extension of the hand-held power tool rechargeable battery in areas other than the coil receiving area, and thus a compact hand-held power tool rechargeable battery, may be achieved.

Furthermore, it is provided that the inductive charging unit includes a coil core unit having a plate area which at least partially shields the at least one first rechargeable battery cell from the inductive charging coil. In the present context, a “coil core unit” is understood in particular to mean a unit which is at least partially formed from a magnetic material, and which is provided for increasing an inductance of a coil. In the present context, a “magnetic material” is preferably understood to mean a ferrimagnetic, in particular soft magnetic, material, for example ferrite. Alternatively, it is also conceivable to use ferromagnetic and/or antiferromagnetic materials. A “plate area” is understood in particular to mean a flat area of the coil core unit having a thickness that is one-half maximum, preferably one-fourth maximum, and particularly preferably one-eighth maximum, of a minimum extension of the coil core unit in a direction perpendicular to the thickness. A “thickness” of the coil core unit is understood in particular to mean an extension of the coil core unit in a direction perpendicular to the coil plane of the inductive charging coil. The statement that the plate area “at least partially shields the at least one first rechargeable battery cell from the inductive charging coil” is understood in particular to mean that field lines of a magnetic field which is generated by the inductive charging coil are at least partially deflected from the at least one rechargeable battery cell by the plate area of the coil core unit. In particular, at a position of the at least one rechargeable battery cell, a field intensity of the magnetic field is thus attenuated by at least 10 percent, advantageously by at least 20 percent, preferably by at least 40 percent, and particularly preferably by at least 80 percent, with respect to a field intensity which prevails without the plate area. In particular, the plate area achieves the shielding of the at least one rechargeable battery cell in that, for a projection of the at least one rechargeable battery cell onto the induction coil, at least 60 percent, advantageously at least 80 percent, and preferably at least 90 percent, of a surface of the projection extends through the plate area. In particular, the coil core unit may have different thicknesses in the plate area. In particular, the plate area of the coil core unit may include a subarea which has a greater thickness than other subareas of the plate area and which preferably extends up to a coil plane, and thus up to an area enclosed by windings of the inductive charging coil in a plane perpendicular to the thickness. The subarea which has a greater thickness than other subareas of the plate area is preferably situated on only one side of the plate area. In particular, the subarea of the plate area which has a greater thickness than other subareas of the plate area may have a basic shape which differs from a basic shape of the plate area on a side facing away from the subarea. In particular, the plate area may have an essentially rectangular basic shape, and the subarea may have an essentially circular basic shape which is augmented on one side. In particular, due to the at least partially shielding of the at least one rechargeable battery cell, a load on the rechargeable battery cells from the magnetic field of the inductive charging coil may be at least reduced, and damage to the hand-held power tool rechargeable battery may be prevented.

In one refinement of the present invention, it is provided that the plate area is at least essentially rectangular. The term “at least essentially rectangular” is understood in particular to mean that the plate area has a surface area which is delimited by four at least essentially straight sides. The term “at least essentially straight sides” is understood in particular to mean sides which include at least one side area, designed as a straight line, whose length corresponds to at least 50 percent of a total length of the side. In particular, the at least essentially straight sides may delimit a rectangular shape, in particular a rectangular shape with rounded edges. In particular, the plate area may have a surface area with a basic shape of a rectangle having rounded sides, the circular subarea of a surface area of the plate area preferably having a greater thickness than other subareas of the plate area and extending to an inner area of the inductive charging coil which is enclosed by windings of the inductive charging coil. In particular, the plate area has at least one axis length which is smaller than a diameter of the inductive charging coil. An “axis length” is understood in particular to mean an extension length in parallel to an at least essentially straight side of the plate area, a length of a main axis or secondary axis of an ellipsoidal plate area, or a diameter of a circular plate area. The at least one further axis length of the plate area is preferably greater than a diameter of the inductive charging coil. The plate area preferably has a rectangular shape with rounded corners, and has an axis length which is smaller than the diameter of the inductive charging coil and extends in parallel to the main direction of extension of the at least one rechargeable battery cell, and has an axis length perpendicular thereto which is greater than the diameter of the inductive charging coil. The coil core unit preferably includes multiple separate core pieces. In the present context, the statement that “the coil core unit includes multiple separate core pieces” is understood in particular to mean that the coil core unit includes at least two, and preferably at least four, pieces which are separately formed and situated separately from one another, and which are made, at least partially, of a magnetic material. In particular, the multiple separate core pieces are situated symmetrically with respect to one another. In particular, the coil core unit, which includes multiple separate core pieces, has a greater mechanical stability, with essentially the same magnetic properties, than a one-piece design of a coil core unit. In particular, a coil core unit having a simple basic shape may be achieved.

Furthermore, it is provided that the hand-held power tool rechargeable battery includes at least one heat distribution element which is provided for distributing waste heat. A “heat distribution element” is understood in particular to mean an element which is provided for at least partially conducting heat, arising locally in a limited area, from the delimited area with the aid of thermal conduction, thermal radiation, or convection and distributing it over a larger area. In particular, the heat distribution element has a thermal conductivity which is at least twice, advantageously at least four times, and preferably at least 10 times, a thermal conductivity of elements which enclose the heat transport element. The phrase “the heat distribution element is provided for distributing waste heat” is understood in particular to mean that the heat distribution element has a surface area which is at least two times, advantageously at least four times, and preferably at least 10 times, larger than a surface area of the delimited area, and which is provided for discharging the heat which is conducted away from the delimited area. “Waste heat” is understood in particular to mean heat which is generated as a by-product during a charge and/or a discharge of the at least one rechargeable battery cell. The heat distribution element is preferably connected to the charging electronics and to the at least one rechargeable battery cell in a thermally conductive manner. The heat distribution element preferably has at least one thermally conductive coating. A “thermally conductive coating” is understood in particular to mean a coating made of a material having a thermal conductivity which is at least two times, advantageously at least four times, and preferably at least 10 times, a thermal conductivity of a material to which the thermally conductive coating is applied. A “coating” is understood in particular to mean a layer which is applied to at least one surface of a support element and which has a thickness that is one-fifth maximum, advantageously one-tenth maximum, and preferably one-twentieth maximum, of a thickness of the support element. The thermally conductive coating preferably has a thickness in the millimeter range. The thermally conductive coating is preferably composed at least partially of aluminum, and is applied to a support element which is designed as a bracket. The bracket is particularly preferably provided for separating the charging electronics at a distance from the at least one rechargeable battery cell. In particular, damage to the hand-held power tool rechargeable battery due to locally increased temperatures, as well as impairment of a charging operation or a discharging operation of the least one rechargeable battery cell due to locally differing temperatures, may be avoided.

Moreover, it is provided that at least the inductive charging unit is designed as a preassembled module. A “preassembled module” is understood in particular to mean that the inductive charging unit, which includes at least the inductive charging coil, a coil carrier on which the inductive charging coil is mounted, and the charging electronics, is assembled in one step during manufacture of the hand-held power tool rechargeable battery, and is installed as a complete module in further steps with other components of the hand-held power tool rechargeable battery, and that the inductive charging unit as a whole is removable from the hand-held power tool and separately testable for functionality and/or installable in a different hand-held power tool rechargeable battery. The preassembled module preferably includes, in addition to the inductive charging unit, at least one rechargeable battery housing component which accommodates the coil carrier and a heat distribution element, designed as a bracket, which holds the individual subelements of the preassembled module together after installation. In particular, simplified installation of the hand-held power tool rechargeable battery may be achieved, and an inductive charging unit which is removable for use in multiple different hand-held power tool rechargeable batteries may be provided.

In addition, a system made up of a hand-held power tool and a hand-held power tool rechargeable battery according to the present invention is provided.

In one refinement of the present invention, it is provided that the hand-held power tool and the hand-held power tool rechargeable battery are separable from one another without tools. The term “separable from one another without tools” is understood in particular to mean that the hand-held power tool rechargeable battery, after being fastened to a hand-held power tool, may be removed by a user of the hand-held power tool without damage. In particular, the hand-held power tool rechargeable battery and/or the hand-held power tool may include fastening means for fastening the hand-held power tool rechargeable battery to the hand-held power tool, and which may be detached by the user for separating the hand-held power tool rechargeable battery from the hand-held power tool. The hand-held power tool rechargeable battery is preferably designed to be insertable or pushable into the hand-held power tool, and may be separated from the hand-held power tool by pulling. In particular, a system with simple exchangeability of the hand-held power tool rechargeable battery may be achieved.

In addition, it is provided that the at least one first rechargeable battery cell is at least essentially enclosed by a handle housing in an installed state of the hand-held power tool and of the hand-held power tool rechargeable battery. The term “at least essentially enclosed by a handle housing” is understood in particular to mean that the at least one first rechargeable battery cell is enclosed by the handle housing along an angular range of at least 180 degrees, preferably at least 270 degrees, and particularly preferably 360 degrees, on at least 50 percent of a length along the main direction of extension on a plane perpendicular to the main direction of extension. The at least one inductive charging coil is preferably situated at least essentially outside the handle housing in the installed state. The term “situated at least essentially outside the handle housing” is understood in particular to mean that at least 50 percent, advantageously at least 70 percent, of a volume is situated outside the handle housing. In particular, a compact system made up of a hand-held power tool and a hand-held power tool rechargeable battery having advantageous guiding properties may be achieved.

In addition, it is provided that the system has an installation direction for installing the hand-held power tool rechargeable battery on the hand-held power tool, which extends at least essentially perpendicularly with respect to a coil plane of the inductive charging unit. In particular, an easily carried out installation may be achieved.

Moreover, a system which includes an inductive charging device and a hand-held power tool rechargeable battery according to the present invention is provided.

In one refinement of the present invention, it is provided that the inductive charging device includes form-fit elements for fastening the hand-held power tool rechargeable battery during a charging phase. “Form-fit elements” are understood in particular to mean elements which are provided for cooperating with corresponding form-fit elements of the hand-held power tool rechargeable battery to provide a form-fit fastening of the hand-held power tool rechargeable battery during the charging phase. In particular, the inductive charging device and the hand-held power tool rechargeable battery are separable from one another without tools. A “charging phase” is understood in particular to mean a period of time during which the at least one rechargeable battery cell becomes charged via electrical energy which is transmitted from the inductive charging device and received by the inductive charging unit of the hand-held power tool rechargeable battery. For example, the inductive charging device may include form-fit elements, designed as recesses, for accommodating a coil receiving area of the rechargeable battery housing which protrudes with respect to a rechargeable battery receiving area. In particular, an interruption in the charging phase or a reduction in a transmission efficiency may be avoided by moving the inductive charging device and the hand-held power tool rechargeable battery relative to one another.

In addition, it is provided that the inductive charging device and the hand-held power tool rechargeable battery include a positioning projection and a positioning recess having basic shapes which are different from one another. A “positioning projection” is understood in particular to mean a surface area which protrudes with respect to adjacent surface areas and which is provided for engaging with the positioning recess. A “positioning recess” is understood in particular to mean a surface area which is recessed with respect to adjacent surface areas and which is provided for engaging with the positioning projection. In particular, the positioning projection and the positioning recess are designed with basic shapes which are different but which correspond to one another; for example, the positioning projection may have a circular shape with a diameter which corresponds to a side length of a square positioning recess. The positioning projection, at least in one area, preferably an end area, of a side preferably has a smaller transverse extension than a transverse extension of the positioning recess, thus simplifying insertion. In particular, simple introduction of the positioning projection into the positioning recess may be achieved.

In addition, an inductive charging unit according to the present invention of a hand-held power tool rechargeable battery is provided.

The hand-held power tool rechargeable battery according to the present invention is not intended to be limited to the use and specific embodiment described above. In particular, for fulfilling a mode of operation described herein, the hand-held power tool rechargeable battery according to the present invention may include a number of individual elements, components, and units which is different from a number stated herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a hand-held power tool rechargeable battery according to the present invention in a partially open view with the housing lid removed, and including three first rechargeable battery cells which have a main direction of extension extending perpendicularly with respect to a coil plane of an inductive charging unit, and three additional rechargeable battery cells.

FIG. 2 shows an exterior view of the hand-held power tool rechargeable battery illustrated in FIG. 1.

FIG. 3 shows a system made up of a hand-held power tool and the hand-held power tool rechargeable battery according to the present invention, in an uninstalled state.

FIG. 4 shows the system made up of the hand-held power tool and the hand-held power tool rechargeable battery in an installed state.

FIG. 5 shows a partial illustration of the hand-held power tool rechargeable battery according to the present invention, with a top view onto the additional rechargeable battery cells and onto an inductive charging coil of the inductive charging unit.

FIG. 6 shows a lateral section of FIG. 4.

FIG. 7 shows an illustration of components of the inductive charging unit as a preassembled module.

FIG. 8 shows a view onto the inductive charging coil and a coil core unit, showing shielding by the coil core unit.

FIG. 9 shows a top view onto the coil core unit and the inductive charging coil.

FIG. 10 shows a view onto a positioning projection of the hand-held power tool rechargeable battery according to the present invention.

FIG. 11 shows a system made up of the hand-held power tool rechargeable battery according to the present invention and an inductive charging device having a positioning recess.

FIG. 12 shows a schematic illustration of different basic shapes of the positioning projection and the positioning recess.

FIG. 13 shows an alternative design of different basic shapes of the positioning projection and the positioning recess.

FIG. 14 shows an alternative exemplary embodiment of a hand-held power tool rechargeable battery according to the present invention, including a single first rechargeable battery cell.

FIG. 15 shows another alternative exemplary embodiment of a hand-held power tool rechargeable battery according to the present invention, including three first rechargeable battery cells having a main direction of extension extending perpendicularly with respect to a coil plane of an inductive charging unit, and including three additional rechargeable battery cells.

FIG. 16 shows an alternative design of an inductive charging device.

FIG. 17 shows a system made up of the alternatively designed inductive charging device and a hand-held power tool rechargeable battery according to the present invention.

DETAILED DESCRIPTION

FIG. 1 shows a hand-held power tool rechargeable battery 10a according to the present invention, including three first rechargeable battery cells 12a, 14a, 16a and an inductive charging unit 20a, which includes an inductive charging coil 22a for charging first rechargeable battery cells 12a, 14a, 16a, in which first rechargeable battery cells 12a, 14a, 16a have a main direction of extension 74a oriented perpendicularly with respect to a coil plane of inductive charging unit 20a. The coil plane of inductive charging unit 20a corresponds to a coil plane of inductive charging coil 22a in which windings of inductive charging coil 22a extend, and which is perpendicular to a winding axis of inductive charging coil 22a. Hand-held power tool rechargeable battery 10a also includes three additional rechargeable battery cells 13a, 15a, 17a having a main direction of extension 76a oriented in parallel to the coil plane of inductive charging unit 20a. Additional rechargeable battery cells 13a, 15a, 17a are situated between first rechargeable battery cells 12a, 14a, 16a and inductive charging coil 22a. First rechargeable battery cells 12a, 14a, 16a and additional rechargeable battery cells 13a, 15a, 17a are formed by lithium-ion rechargeable batteries having a nominal voltage of 3.6 V. In principle, rechargeable batteries which include other electrolytes, for example nickel-metal hydride rechargeable batteries, nickel-cadmium rechargeable batteries, or nickel-zinc rechargeable batteries, and/or which have other nominal voltages may also be used as rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a. First rechargeable battery cells 12a, 14a, 16a are connected together in a series connection to form a first cell block having a total voltage of 10.8 V, and additional rechargeable battery cells 13a, 15a, 17a are connected together in a series connection to form a second cell block having a total voltage of 10.8 V. The first cell block is provided for initially supplying a hand-held power tool 36a with current, and the second cell block is provided for supplying hand-held power tool 36a with current after a discharge of the first cell block, so that hand-held power tool rechargeable battery 10a overall has twice the capacity compared to use of a single cell block made up in each case of three first rechargeable battery cells 12a, 14a, 16a or additional rechargeable battery cells 13a, 15a, 17a. In principle, cells of first rechargeable battery cells 12a, 14a, 16a as well as cells of additional rechargeable battery cells 13a, 15a, 17a may be connected together in series in a cell block. In addition, all rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a may be connected together in a shared cell block. In one simple specific embodiment of hand-held power tool rechargeable battery 10a, hand-held power tool rechargeable battery 10a includes only a single cell block with three first rechargeable battery cells 12a, 14a, 16a, which in an installed state are accommodated at least partially in a handle 38a of a hand-held power tool 36a. This specific embodiment is indicated in FIG. 1 in that the second cell block made up of additional rechargeable battery cells 13a, 15a, 17a, not contained in this specific embodiment, is illustrated in dashed lines. In one alternative specific embodiment, hand-held power tool rechargeable battery 10a includes only one of the rechargeable battery cells 12a, 14a, 16a. In another alternative specific embodiment, hand-held power tool rechargeable battery 10a includes only two of the rechargeable battery cells 12a, 14a, 16a. In all three mentioned specific embodiments in which hand-held power tool rechargeable battery 10a includes two or three of the rechargeable battery cells 12a, 14a, 16a, an inductive charging coil 22a for charging the at least one of the rechargeable battery cells 12a, 14a, 16a is provided. The at least one of the rechargeable battery cells 12a, 14a, 16a has a main direction of extension 74a which is oriented perpendicularly with respect to a coil plane of inductive charging unit 20a.

Inductive charging unit 20a includes a coil core unit 24a with a plate area 62a which shields first rechargeable battery cells 12a, 14a, 16a and additional rechargeable battery cells 13a, 15a, 17a from inductive charging coil 22a. Rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a are situated in receiving spaces of rechargeable battery cell supports 86a, made of a plastic. Rechargeable battery cell supports 86a are not illustrated in FIG. 1 for better depiction of the arrangements of rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a within hand-held power tool rechargeable battery 10a. Rechargeable battery cell supports 86a have an open design in a direction in parallel to main direction of extensions 74a, 76a of rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a, so that rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a may be pushed into and pulled out of rechargeable battery cell supports 86a along this direction. Rechargeable battery cell supports 86a fasten rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a relative to one another, and partially enclose them in a direction perpendicular to main directions of extension 74a, 76a. Coil core unit 24a is situated between inductive charging coil 22a and rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a, and separates them from one another (FIG. 6). Inductive charging coil 22a is illustrated in dashed lines in FIG. 1 to show its arrangement relative to rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a. Hand-held power tool rechargeable battery 10a also includes a rechargeable battery housing 18a for accommodating inductive charging unit 20a and rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a, including a coil receiving area 44a for accommodating inductive charging coil 22a which at least partially forms a form-fit element, and a rechargeable battery cell receiving area 46a for accommodating additional rechargeable battery cells 13a, 15a, 17a, which is recessed relative to coil receiving area 44a. Viewed in a plane perpendicular to main direction of extension 74a of first rechargeable battery cells 12a, 14a, 16a, coil receiving area 44a protrudes from rechargeable battery cell receiving area 46a along at least one axis. Rechargeable battery housing 18a includes a central housing component 30a and two lateral housing components 32a, 34a which form coil receiving area 44a and rechargeable battery cell receiving area 46a, and is made of a plastic. Housing components 32a, 34a, which form coil receiving area 44a, define a left side and a right side, and end areas of central housing component 30a define a front side and a rear side of hand-held power tool rechargeable battery 10a, a display including LED elements for indicating a state of charge being situated on the front side of hand-held power tool rechargeable battery 10a. Hand-held power tool rechargeable battery 10a also includes connecting elements, not illustrated in greater detail, for establishing an electrically conductive connection between rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a and a current collector.

FIG. 2 shows hand-held power tool rechargeable battery 10a illustrated in FIG. 1, including a completely closed rechargeable battery housing 18a with a housing component 48a which is placed on housing components 30a, 32a, 34a and which forms an upper closure. Housing component 48a encloses first rechargeable battery cells 12a, 14a, 16a, and on opposite sides includes locking elements 106a which are designed as detent elements. At the upper end of rechargeable battery housing 18a in FIG. 2, hand-held power tool rechargeable battery 10a includes a contact area, not indicated in greater detail in FIG. 2, including electrical contact elements for electrically contacting with complementary electrical contact elements of a hand-held power tool.

FIG. 3 shows a system 50a made up of a hand-held power tool 36a and hand-held power tool rechargeable battery 10a according to the present invention in an uninstalled state. Hand-held power tool 36a is formed by a cordless screw drill, which includes a handle 38a with a handle housing 40a which encloses a hand-held power tool rechargeable battery receptacle 84a. Situated on handle 38a is a control switch 42a which, when actuated, closes an electric circuit between hand-held power tool rechargeable battery 10a and hand-held power tool 36a, so that hand-held power tool 36a is supplied with current for operation. A housing component 48a, which in the illustrated specific embodiment is designed as a housing lid, together with housing components 30a, 32a, 34a forms rechargeable battery housing 18a of hand-held power tool rechargeable battery 10a. Hand-held power tool rechargeable battery 10a is fastened to housing component 48a of hand-held power tool 36a with the aid of locking elements 106a. Hand-held power tool rechargeable battery 10a is fastened without tools to hand-held power tool 36a by inserting it into hand-held power tool rechargeable battery receptacle 84a with locking elements 106a (FIG. 4). An installation direction 78a for installing hand-held power tool rechargeable battery 10a on hand-held power tool 36a extends perpendicularly with respect to the coil plane of inductive charging unit 20a, and thus in parallel to main direction of extension 74a of first rechargeable battery cells 12a 14a, 16a. Hand-held power tool rechargeable battery 10a is thus installed on hand-held power tool 36a by one insertion motion. In an installed state of hand-held power tool 36a and of hand-held power tool rechargeable battery 10a, first rechargeable battery cells 12a 14a, 16a are enclosed by handle housing 40a along an angular range of 360 degrees over 60 percent of a length along main direction of extension 74a on a plane perpendicular to main direction of extension 74a. In the installed state, inductive charging coil 22a is situated outside of handle housing 40a, an overall volume of inductive charging coil 22a being situated outside of handle housing 40a. In the installed state, additional rechargeable battery cells 13a, 15a, 17a are likewise situated outside of handle housing 40a. Hand-held power tool 36a and hand-held power tool rechargeable battery 10a are separable from one another without tools, and hand-held power tool rechargeable battery 10a may be pulled from hand-held power tool rechargeable battery receptacle 84a after actuating a release element, not illustrated.

A diameter of inductive charging coil 22a is greater than a main length of extension of additional rechargeable battery cells 13a, 15a, 17a, which is formed by a length along main direction of extension 76a (FIG. 5). The diameter of inductive charging coil 22a is moreover greater than a diameter of first rechargeable battery cells 12a, 14a, 16a in a direction perpendicular to main direction of extension 74a. In addition, the diameter of the inductive charging coil is greater than a length of a maximum extension of first rechargeable battery cells 12a, 14a, 16a, for example a diagonal between two diametrically opposed corner areas of first rechargeable battery cells 12a, 14a, 16a. The diameter of inductive charging coil 22a is also greater than a main length of extension of first rechargeable battery cells 12a, 14a, 16a. Inductive charging coil 22a thus protrudes beyond all rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a, thus achieving rapid charging of rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a. Inductive charging coil 22a is situated in coil receiving area 44a of rechargeable battery housing 18a, which protrudes beyond rechargeable battery cell receiving area 46a. Inductive charging coil 22a is separated from rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a by plate area 62a of coil core unit 24a, and is illustrated in dashed lines in FIG. 5 for depicting the position in the areas covered by plate area 62a. Plate area 62a is rectangular, and has the shape of a square with rounded corners. Axis lengths 80a, 82a of plate area 62a are smaller than a diameter of inductive charging coil 22a (FIG. 8). Coil core unit 24a includes four separate core pieces 26a, 27a, 28a, 29a, each of which corresponds to one-fourth of the square with rounded corners (FIG. 9). Individual core pieces 26a, 27a, 28a, 29a rest in a coil carrier 60a in which inductive charging coil 22a is also clamped, and are separated from one another by plastic elements of coil carrier 60a. In an area facing away from the rounded corners, individual core pieces 26a, 27a, 28a, 29a on one side have an area with an increased thickness, which in the installed state is situated within the coil plane of inductive charging coil 22a. In the installed state of inductive charging coil 22a, the areas with increased thickness are enclosed by and adjoin the inductive charging coil (FIG. 8).

Inductive charging unit 20a includes inductive charging coil 22a, coil core unit 24a, charging electronics 52a, coil carrier 60a, central housing component 30a, which fastens coil carrier 60a, and a heat distribution element 54a, and is designed as a preassembled module 58a which may be removed separately so that inductive charging coil 22a and charging electronics 52a may be checked for proper functioning (FIG. 7). Heat distribution element 54a is provided for distributing waste heat of charging electronics 52a during charging of rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a, and distributing waste heat of rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a during a discharge, thus avoiding localized overheating. For this purpose, heat distribution element 54a is designed as a bracket which extends through hand-held power tool rechargeable battery 10a along a main axis of central housing component 30a (FIG. 6). Side areas of heat distribution element 54a are in contact with charging electronics 52a, and a central area of heat distribution element 54a is in contact on one side with rechargeable battery cell support 86a, in which rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a are situated, so that heat may flow between rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a and charging electronics 52a via heat distribution element 54a. Heat distribution element 54a has a thermally conductive coating 56a of aluminum. In one alternative embodiment, heat distribution element 54a may also be designed as a component made completely of aluminum. Charging electronics 52a are partially coated with a copper layer for shielding rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a from inductive charging coil 22a.

FIG. 10 shows an oblique view of hand-held power tool rechargeable battery 10a from below, with a view of a bottom side of rechargeable battery housing 18a facing away from first rechargeable battery cells 12a, 14a, 16a and housing component 48a. Situated on the bottom side is a positioning projection 64a having a square basic shape with rounded corners, which has contact with the base when hand-held power tool rechargeable battery 10a is placed with the bottom side on a base, whereas other subareas of the bottom side are free of contact with the base. Positioning projection 64a is also provided for engaging with a positioning recess 68a of an inductive charging device 66a.

FIG. 11 shows a system 72a including inductive charging device 66a, which includes an inductive charging unit 88a, and hand-held power tool rechargeable battery 10a. On a top side, inductive charging unit 88a has a support surface 90a with positioning recess 68a, on which hand-held power tool rechargeable battery 10a is placed for charging rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a. Positioning recess 68a has a circular basic shape and a depth of 3 mm. However, other dimensions which appear meaningful to those skilled in the art are conceivable, such as a depth of 2 mm, 5 mm, or only 1 mm. Positioning projection 64a has a shoulder height which corresponds to the depth of positioning recess 68a. Positioning projection 64a and positioning recess 68a thus have different basic shapes. The dimensions of positioning projection 64a and of positioning recess 68a are adapted to one another, and in particular the dimensions of positioning recess 68a are adapted to securely enclose positioning projection 64a with little play. A small tolerance is provided between the dimensions of positioning projection 64a and of positioning recess 68a. Locking of positioning projection 64a into positioning recess 68a is haptically perceivable by a user, and indicates to the user a positioning of hand-held power tool rechargeable battery 10a on inductive charging unit 88a of inductive charging device 66a which is optimal for a charging operation. In the illustrated variant, positioning projection 64a is provided with the square basic shape with rounded corners for accommodation in circular positioning recess 68a (FIG. 12); alternatively, positioning projection 64a may have a circular basic shape and be provided for accommodation within a positioning recess 68a having a square basic shape (FIG. 13). Alternatively, it is also possible for inductive charging unit 88a of inductive charging device 66a to include a positioning projection 64a, and for hand-held power tool rechargeable battery 10a to include a positioning recess 68a.

During charging of rechargeable battery cells 12a, 13a, 14a, 15a, 16a, 17a, electrical energy is transmitted with the aid of induction via an induction coil (not illustrated) of inductive charging unit 88a of inductive charging device 66a to inductive charging coil 22a of hand-held power tool rechargeable battery 10a, where it induces an electric current. The electric current is transformed and the charging is controlled with the aid of charging electronics 52a. Due to the accommodation of positioning projection 64a in positioning recess 68a when hand-held power tool rechargeable battery 10a is placed on inductive charging unit 88a of inductive charging device 66a during a charging phase of hand-held power tool rechargeable battery 10a, inductive charging coil 22a of hand-held power tool rechargeable battery 10a and the induction coil of inductive charging unit 88a of inductive charging device 66a are situated relative to one another in a position in which a high transmission efficiency is achieved. A displacement of hand-held power tool rechargeable battery 10a and of inductive charging unit 88a of inductive charging device 66a relative to one another during the charging phase, for example due to inadvertently striking them, is partially avoided by the accommodation of positioning projection 64a in positioning recess 68a. In addition, inductive charging unit 88a of inductive charging device 66a includes form-fit elements 70a for fastening hand-held power tool rechargeable battery 10a during the charging phase. Form-fit elements 70a are designed as retaining tabs, and have a form-fit recess which is provided for accommodating coil receiving area 44a of hand-held power tool rechargeable battery 10a. Form-fit elements 70a are mounted in an elastically supported manner on opposite sides of inductive charging unit 88a of inductive charging device 66a, and may be deflected in a direction in parallel to a normal direction of support surface 90a. For placing and fastening hand-held power tool rechargeable battery 10a on inductive charging unit 88a of inductive charging device 66a, hand-held power tool rechargeable battery 10a is set on inductive charging device 66a at an angle, so that coil receiving area 44a engages beneath form-fit elements 70a on one side. Hand-held power tool rechargeable battery 10a is subsequently oriented in parallel to support surface 90a so that form-fit elements 70a are deflected in an upward direction, facing away from support surface 90a, in the direction of the normal direction. Hand-held power tool rechargeable battery 10a is now inserted between form-fit elements 70a on support surface 90a until positioning projection 64a engages with positioning recess 68a. Form-fit elements 70a subsequently engage around coil receiving area 44a of rechargeable battery housing 18a from above. Form-fit elements 70a now secure hand-held power tool rechargeable battery 10a in position, preventing it from being lifted off. To remove hand-held power tool rechargeable battery 10a from inductive charging unit 88a of inductive charging device 66a, hand-held power tool rechargeable battery 10a is pulled with one action in which hand-held power tool rechargeable battery 10a is pulled in a direction along a main extension of the form-fit recess of form-fit elements 70a, and at the same time is lifted in the normal direction of support surface 90a, and is pulled from inductive charging device 66a. Form-fit elements 70a are mounted on a main body of inductive charging unit 88a of inductive charging device 66a with a clip fastener, and are designed to be removable from the main body without tools.

In principle, form-fit elements 70a may also have a one-piece design which is inseparably connected to the main body. In another possible, alternative embodiment, form-fit elements 70a may be laterally deflectable in an elastically supported manner, and are deflected to the side for fastening hand-held power tool rechargeable battery 10a. To remove hand-held power tool rechargeable battery 10a in the alternative embodiment of inductive charging unit 88a of inductive charging device 66a, form-fit elements 70a are once again deflected to the side so that hand-held power tool rechargeable battery 10a may be pulled out.

FIGS. 14 through 17 show three further exemplary embodiments of the present invention. The following descriptions and the drawings are limited essentially to the differences between the exemplary embodiments, whereby in principle, with regard to identically denoted components, in particular with regard to components having identical reference numerals, reference may also be made to the drawings and/or the description of the other exemplary embodiments, in particular in FIGS. 1 through 13. To distinguish between the exemplary embodiments, the letter a is added as a suffix to the reference numerals in the exemplary embodiment in FIGS. 1 through 13, and the letters b through d replace the letter a in the exemplary embodiments in FIGS. 14 through 17.

FIG. 14 shows one alternative exemplary embodiment of a hand-held power tool rechargeable battery 10b according to the present invention, including a first rechargeable battery cell 12b, three additional rechargeable battery cells 13b, 15b, 17b, and an inductive charging unit 20b, which includes an inductive charging coil 22b for charging first rechargeable battery cell 12b and additional rechargeable battery cells 13b, 15b, 17b, in which first rechargeable battery cell 12b has a main direction of extension 74b oriented perpendicularly with respect to a coil plane of inductive charging unit 20b. The three additional rechargeable battery cells 13b, 15b, 17b have a main direction of extension 76b which extends in a coil plane of inductive charging unit 20b. Hand-held power tool rechargeable battery 10b has a design similar to that of the previous exemplary embodiment, except that it includes an inductive charging coil 22b having a smaller diameter than in the previous example. Since hand-held power tool rechargeable battery 10b includes a single first rechargeable battery cell 12b with a main direction of extension 74b extending perpendicularly with respect to the coil plane of inductive charging unit 20b, hand-held power tool rechargeable battery 10b may be inserted into a handle housing having a smaller diameter than in hand-held power tool rechargeable battery 10a illustrated in the previous exemplary embodiment. First rechargeable battery cell 12b is connected to additional rechargeable battery cell 13b in a series connection to form a first cell block having a total voltage of 7.2 V, and additional rechargeable battery cells 15b, 17b are connected together to form a second cell block having a total voltage of 7.2 V, which is used for supplying current after discharge of the first cell block. In principle, hand-held power tool rechargeable battery 10b may also include only a single rechargeable battery cell 12b, as indicated by an illustration of additional rechargeable battery cells 13b, 15b, 17b in dashed lines.

FIG. 15 shows a third exemplary embodiment of a hand-held power tool rechargeable battery 10c according to the present invention, including three first rechargeable battery cells 12c, 14c, 16c and an inductive charging unit 20c, which includes an inductive charging coil 22c for charging first rechargeable battery cells 12c, 14c, 16c, in which first rechargeable battery cells 12c, 14c, 16c have a main direction of extension 74c oriented perpendicularly with respect to a coil plane of inductive charging unit 20c. Hand-held power tool rechargeable battery 10c also includes three additional rechargeable battery cells 13c, 15c, 17c having a main direction of extension 76c oriented in parallel to the coil plane of inductive charging unit 20c. The exemplary embodiment largely corresponds to the first exemplary embodiment, except that main direction of extension 76c of the three additional rechargeable battery cells 13c, 15c, 17c in the third exemplary embodiment extends perpendicularly with respect to main direction of extension 76a of the three additional rechargeable battery cells 13a, 15a, 17a in the first exemplary embodiment.

FIG. 16 illustrates one alternative embodiment of a system 72d having an alternative design of an inductive charging device 66d and a hand-held power tool rechargeable battery 10d. The design of hand-held power tool rechargeable battery 10d corresponds to that of the first exemplary embodiment. Inductive charging device 66d includes an inductive charging unit 88d, which has a design that is essentially similar to the first exemplary embodiment, and additionally includes a frame 92d which includes form-fit elements 70d of inductive charging device 66a for fastening hand-held power tool rechargeable battery 10d during a charging phase. Frame 92d includes a support 104d, formed by surfaces of frame components, above which two side brackets 96d, 98d, and a retaining bracket 100d extending transversely thereto on one side, rise (FIGS. 17a, 17b). Retaining bracket 100d extends from side bracket 96d to side bracket 98d. Inductive charging unit 88d is placed on support 104d, and is then situated within frame 92d. A side of frame 92d which is designed as an insertion opening 102d and which is provided for inserting hand-held power tool rechargeable batteries 10d into form-fit elements 70d and onto support surface 90d is situated opposite from retaining bracket 100d (FIG. 16). Form-fit elements 70d are provided for engaging from above around coil receiving area 44d of a rechargeable battery housing 18d of hand-held power tool rechargeable battery 10d, which protrudes with respect to a rechargeable battery cell receiving area 46d, during the charging phase, so that hand-held power tool rechargeable battery 10d is secured in position on support surface 90d. Hand-held power tool rechargeable battery 10d and inductive charging unit 88d of inductive charging device 66d include a pair, made up of a positioning recess and a positioning projection, having different basic shapes, and which are not illustrated in FIG. 16 for reasons of perspective. Frame 92d is made of a plastic, and is made up of two partial shells which are fixedly connected to one another by screws. In principle, it is also conceivable for frame 92d to be designed as a single solid component.

Number	Date	Country	Kind
102012112846.4	Dec 2012	DE	national
102013201706.5	Feb 2013	DE	national
102013226241.8	Dec 2013	DE	national

HAND-HELD POWER TOOL RECHARGEABLE BATTERY

Information

Publication Number

Date Filed

Date Published

Inventors

Original Assignees

CPC

International Classifications

Abstract

Description

Claims

Priority Claims (3)

PCT Information