System with machine tool and power supply, interface and power supply - Patents.com

Abstract

The present invention relates to a system (100) including a machine tool (10) and a power supply (20), the power supply being provided for supplying power to the machine tool. The power supply may be removably connected to the machine tool by an interface (30), the interface (30) including at least one female contact mating part (40) and one male contact mating part (50). The female contact mating part and the male contact mating part contact each other at at least one first contact area (110) and a second contact area (120). The first contact area may be defined by a first contact normal force, while the second contact area may be defined by a second contact normal force, the first contact normal force (112) and the second contact normal force (122) having different orientations. The interface may also have an elastic element for reducing relative movement between the male contact mating part and the female contact mating part. In a further aspect, the invention relates to an interface and a power supply for transmitting electrical power.

Description

[Technical field]

[0001] The present invention relates to a system including a power tool and an energy supply device, the energy supply device being provided for supplying electrical energy to the power tool. The energy supply device may be removably connected to the power tool via an interface, the interface including at least a female contact mating and a male contact mating. The female contact mating and the male contact mating contact each other at least at a first contact area and a second contact area. The first contact area may be defined by a first contact normal force, while the second contact area may be defined by a second contact normal force, the first contact normal force and the second contact normal force having different orientations. Additionally, the interface may include elastic means for reducing relative movement between the male contact mating and the female contact mating. In a further aspect, the present invention relates to an interface and an energy supply device for transmitting electrical energy. [Background technology]

[0002] So-called cordless power tools, such as battery-powered electric screwdrivers, drills, saws, grinders, etc., can be connected to an energy supply device for energy supply purposes. The energy supply device can be configured as or include, for example, an accumulator battery. The accumulator battery usually has a number of energy storage cells, also known as accumulator cells, by means of which electrical energy can be received, stored and discharged again. When the accumulator battery is connected to the power tool, the electrical energy stored in the energy storage cells can be supplied to the consumer of the power tool, for example a brushless electric motor. For charging purposes, i.e. to apply electrical energy to the energy storage cells, the accumulator battery is connected to a charging device, such as a charger, whereby electrical energy can enter the energy storage cells.

[0003] When using or working with a battery-operated power tool, high vibrations and shocks can occur to the power tool and to the energy supply device connected to the power tool. This is especially true when the power tool is a demolition tool, such as a chipping hammer or demolition hammer. The vibrations and shocks during use of the power tool place a certain amount of strain on virtually all components and assemblies of the power tool and the energy supply device. This strain can eventually lead to damage to the respective components or failure of the entire power tool.

[0004] The interface between the power tool and the energy supply device constitutes a particular technical challenge: at the interface, the electrical contacts of the power tool and the electrical contacts of the energy supply device ("contact counterparts") are connected to one another so that the electrical energy stored in the energy storage cell can be transferred from the accumulator to the power tool.

[0005] In particular, conventional interfaces as known from the prior art have contacts for electrical energy transmission in which so-called contact normal forces act only in one direction, for example in the clamping or plugging direction. For the purposes of the present invention, the term "contact normal force" is understood to mean the force acting on the contact area between the contact counterparts of the interface. In other words, it can refer to the force with which the contact counterparts are pressed against each other to form a contact. In this context, a high contact normal force is desirable on the one hand in order to obtain a good mechanical contact between the power contacts. On the other hand, the contact normal force needs not to be too large in order to keep undesirable plugging cycle wear low.

[0006] Another drawback of conventional interfaces is that there is often only one contact area for transmitting electrical energy, so the energy transmission potential of the interface may not be optimally utilized.

[0007] For example, US Patent Application Publication No. 2016 0126 533 A1 relates to a transportation system for a convertible battery pack, and discloses a transportation coupler that can reduce the capacity of the battery pack during transportation.

[0008] DE 10 2016 120 329 A1 describes a connection device for an electric device or energy accumulator.

[0009] JP 2007-105816 A describes a battery-powered power tool and in particular a connection structure between terminals on a housing of the power tool and terminals on a battery, and US 2008 0084 181 A1 describes a self-adjusting terminal block for a battery pack.

[0010] US Patent Application Publication No. 2014 0326 477 A1 describes a power tool having an insulation system for a battery pack.

[0011] EP 3 653 340 A1 discloses a hand-held power tool having a battery interface. Summary of the Invention [Problem to be solved by the invention]

[0012] The object of the present invention is to overcome the above-mentioned deficiencies and drawbacks of the prior art and to provide an interface and a system consisting of a power tool and an energy supply device, which allows the transfer of particularly high discharge currents or large amounts of electrical energy from the energy supply device to the power tool and which extends the service life of the interface. In particular, a person skilled in the art would like the interface to continue to operate optimally even after many plugging or clamping operations and to function robustly in the face of small mechanical deviations. [Means for solving the problem]

[0013] This object is achieved by the subject matter of the independent claims. Advantageous embodiments related to the subject matter of the independent claims can be found in the dependent claims.

[0014] According to the present invention, a system is provided that includes a power tool and an energy supply device, the energy supply device being configured to supply electrical energy to the power tool. The energy supply device can be detachably connected to the power tool via an interface, the interface comprising at least a female contact mating part and a male contact mating part. The female contact mating part and the male contact mating part contact each other at a first contact area and a second contact area. In the context of the present invention, this preferably means that the interface comprises a first contact area and a second contact area, and at least one female contact mating part and at least one male contact mating part contact each other at a contact area of ​​the interface. As a result, at least one female contact mating part and at least one male contact mating part can form a pair of power contacts, and current or electrical energy is exchanged between the power contacts via the contact areas. In the context of the present invention, it is particularly preferred that electrical energy flows from the energy supply device towards the power tool when the energy supply device and the power tool are connected to each other via the interface. The transfer of electrical energy from the energy supply device to the power tool is made possible in particular by an effective contact between at least one female contact mating part and at least one male contact mating part, the effective contact in connection with the present invention being established or formed by at least two contact areas between at least one female contact mating part and at least one male contact mating part. By providing at least two contact areas between the power contacts of the interface, the contact resistance between the at least one female contact mating part and the at least one male contact mating part can be significantly reduced. This advantageously allows a higher current to be transferred from the energy supply device to the power tool. As a result, the proposed interface may allow a higher discharge current of the interface, so that the proposed energy supply device is particularly suitable for energy supply to particularly powerful power tools. Naturally, the interface can also have more than two, for example three, four, five or more, contact areas between the contact mating parts.

[0015] In connection with the present invention, it is preferred that the power contacts are designed as flat contacts. Thus, the interface comprises a plurality of contacts, i.e. flat contacts, which allow the transfer of electrical energy from the energy supply device to the power tool in at least two contact areas. In this case, the plurality of contacts preferably have contact normal forces directed in different directions. As a result, a particularly robust interface can be provided, since the contact normal forces by the interface act not only in the clamping or plugging direction of the interface, but also in different directions. Furthermore, providing contact normal forces in different directions can prevent the contacts from "lifting", i.e. from moving undesirably away from each other, during high accelerations.

[0016] Tests have shown that the proposed interface is optimal for resolving the conflicting objectives of the desired low contact resistance, necessary for transmitting large amounts of current and energy between the power contacts, on the one hand, and the desired low plug-in cycle wear, on the other hand. The interface may be preferably described as a flat contact system having at least one male contact mating and at least one female contact mating.

[0017] Furthermore, by providing two or more contact areas between at least one female contact mating and at least one male contact mating, it can be ensured that the grade, quality and quantity of the transmission of electrical energy from the energy supply device to the power tool is less dependent on manufacturing tolerances and relaxation processes. Advantageously, the proposed energy supply device is less susceptible to minor mechanical deviations at the contact mating parts of the interface due to non-exact adherence to manufacturing specifications or reduced contact normal forces due to relaxation, especially relaxation due to high thermal loads on the elastic spring mounting area, and still be able to guarantee a high discharge current of the energy supply device.

[0018] A further advantage of the present invention is that by providing two or more contact areas between the power contacts of the interface, the relative distance between the contact counterparts can be significantly reduced, since such a relative distance between the power contacts can lead to wear and reduced energy transmission from the energy supply device to the power tool, reducing the relative movement between the contact counterparts of the interface contributes significantly to maintaining the current transmission capacity of the interface at a high level, thus enabling the transmission of high discharge currents.

[0019] According to the invention, it is provided that the first contact area can be defined by a first contact normal force and the second contact area can be defined by a second contact normal force, the first contact normal force and the second contact normal force having different orientations. In other words, the orientations or directions of the two contact normal forces are not coincident and are different. It is preferred in connection with the invention that the orientations and / or directions of the first contact normal force and the second contact normal force are not coincident and differ by an angle range delta. The statement "the contact area can be defined by a contact normal force" or is defined preferably means in connection with the invention that the corresponding contact normal force indicates or describes the direction in which the contact counterparts act or press against each other at the corresponding contact area. For example, the first contact normal force of the first contact area of ​​the interface can be defined by the legs of the female contact counterpart pressing against the blades of the male contact counterpart. This slight pressure is in particular caused by the elastic and resilient material (e.g. spring steel) of the female contact counterpart. In the first contact area, the first contact normal force may be, for example, substantially perpendicular to an imaginary axis passing through the blade of the male contact counterpart. In other words, an imaginary axis, preferably passing through the center of the blade of the male contact counterpart, can be considered as being substantially perpendicular, i.e. "normal", to the first contact normal force of the first contact area of ​​the interface. Possible orientations of the contact normal forces of the various contact areas are shown, for example, in FIG. 4. FIG. 4 also shows an insertion direction in which the contact counterparts of the interface can be joined to one another. In the context of the present invention, it is preferred that the first contact normal force is directed substantially perpendicular to this insertion direction and the second contact normal force is directed substantially parallel to the insertion direction. Thus, the first contact normal force and the second contact normal force are preferably substantially perpendicular to each other. Preferably, the insertion direction coincides with an imaginary axis that can be imaginarily placed through the blade of the male contact counterpart.

[0020] In the context of the present invention, it is preferred that the contact areas each comprise a plurality of contact points between their contact counterparts, which in the context of the present invention preferably means that the contact counterparts of the first contact area and / or the second contact area can contact each other at one or more contact points in order to transmit electrical energy.

[0021] In the second contact area, for example, the stopper of the female contact counterpart can come into contact with the contact surface of the male contact counterpart, so that a current can flow through the contact surface. The second contact area can be described by a second contact normal force, which preferably indicates the direction in which the relevant components of the contact counterpart (in this case the stopper and the contact surface) act or press against each other. In the context of the present invention, the second contact normal force can for example be substantially parallel to the insertion direction. It is therefore preferred in the context of the present invention that the first and second contact normal forces have different orientations. In the previously described exemplary embodiment of the present invention shown in FIG. 4, it is preferred in the context of the present invention that the first and second contact normal forces are directed substantially perpendicular to each other. The stopper of the female contact mating part and the contact surface of the male contact mating part together form a second contact area, which has been shown to be particularly suitable for transmitting high discharge currents from the energy supply device to the power tool due to the close contact between the contact mating parts, which can be further improved by spring mounting at least one of the contact mating parts, as described further below.

[0022] For example, the female contact partner may have a stopper which cooperates with the contact or support surface of the male contact partner in order to form a particularly stable connection between the contact partners. If the female contact partner comprises exactly one stopper, it is preferred in connection with the present invention that this one stopper is arranged in the symmetrical plane of the female contact partner. If the female contact partner comprises two stoppers, it is preferred in connection with the present invention that these two stoppers are present with the two stoppers arranged as far apart as possible in order to ensure an improved support of the contact partner. The contact or support surface of the male contact partner may also have a ramp in order to facilitate the establishment of the connection between the contact partners and to prevent mechanical damage to the contact partners.

[0023] The statement "substantially perpendicular" is not an unclear concept for the skilled person, since he knows that this statement includes not only contact normal forces that are mathematically exactly perpendicular to each other, but also contact normal forces that exhibit a slight deviation from mathematically exact regularity. Such deviations can be, for example, in the range of ±10° or ±10% with respect to a right angle (90°). In the context of the present invention, the first contact area is preferably formed by at least one leg of the female contact counterpart and one blade of the male contact counterpart. In the context of the present invention, the female contact counterpart is preferably formed as a receiving terminal that preferably includes two legs. The legs can be formed, for example, from a resilient elastic material and can press against the blade of the male contact counterpart due to the elastic properties of the leg material. This contact between at least one leg of the female contact counterpart and the blade of the male contact counterpart preferably forms the first contact area of ​​the interface. In connection with the present invention it is particularly preferred that the first contact area is formed by two legs of the female contact counterpart and a central area of ​​a blade of the male contact counterpart.

[0024] The first contact normal force and the second contact normal force have different orientations in the context of the present invention. In this context, the angle delta between the contact normal forces may be about 90 degrees, i.e., the contact normal forces may form a substantially right angle.

[0025] Such contact normal forces which are substantially perpendicular to one another are shown, for example, in Figs. 4-6 or 9 (top). The first contact normal force is preferably present in the first contact area and is substantially perpendicular to the insertion direction of the energy supply device into the power tool, and the second contact normal force is present in the second contact area and is substantially parallel to the insertion direction of the energy supply device into the power tool. The first contact normal force preferably has no force component in the insertion direction, whereas the second contact normal force acts substantially entirely in the insertion direction. It has been shown that a maximum possible second force normal force in the insertion direction can advantageously result in a particularly good current conductivity of the interface and a particularly stable connection between the contact counterparts.

[0026] In particular in the case of multi-dimensional and dynamic loading of the contact system due to high accelerations during rough work on construction sites, especially with impact power tools, it is very advantageous if the contact normal forces are present in different orientations. For example, as soon as high accelerations occur for a first contact normal force in a first orientation, there is a risk that this first contact area will open. The opening of a contact exposed to high currents can lead to spark discharges, which can result in very high local contact material wear, an increase in the contact resistance and a significant reduction in the contact life. Such an opening of a contact can also be referred to as contact lifting, which can for example lead to spark discharges or in the worst case to a burning out of the contact. If the contact normal forces are present in different orientations, then when the first contact area lifts as described above, a second contact area with a different orientation can take over the current flow. As a result, the lifting contact is not energized at all or at least is energized with a low current, which avoids or reduces spark discharges despite the lifting, so that the contact is not damaged or only slightly damaged and its service life is not impaired.

[0027] It has been found to be particularly advantageous if the angle of the contact normal force direction is approximately 90 degrees, since this results in a very low acceleration in the second contact area when the acceleration direction acts substantially against the first contact normal force.

[0028] The contacts of the first contact area are further exposed to wear due to mating, which may damage the local contact material, thus worsening the contact resistance and impairing the contact life. Preferably, if the second contact force is directed substantially perpendicular to the first contact normal force, it may act substantially in the insertion direction. Thus, the second contact area is not loaded by the relative motion during mating and therefore experiences very little mating wear.

[0029] In the context of the present invention, it is preferred that the second contact area is biased with an independent contact normal force. This means that even if the elastic element biasing the first contact area is damaged, for example by breaking or loosening, there is still an independent elastic element which continues to bias the second contact area. In this way, a functional redundancy can be created, which ensures the functional reliability of the contact system, especially under high mechanical loads in harsh environmental conditions. In the context of the present invention, the biasing of the elastic means for reducing the relative distance between the contact counterparts preferably acts in or against the insertion direction. On the other hand, the female contact counterpart is often formed as an elastic bending contact, the elastic force generated by the bending contact is advantageously substantially perpendicular to the biasing, which biasing preferably acts in or against the insertion direction. This elastic spring mounting in the two spatial directions can prevent the contacts from lifting up and can ensure a particularly stable current flow even under construction site conditions.

[0030] The energy supply device and the power tool can be connected to each other such that a linear or "angled" stop is formed between the components of the interface. In the case of a linear stop, the second contact normal force is preferably formed in the second contact area so as to be arranged substantially parallel to the insertion direction of the energy supply device (see FIG. 9 (top)). The angled stop is preferably characterized in that an angle of less than 90 degrees is formed between the first and second contact normal forces. In the case of an angled stop formed between the components of the power tool, the second contact normal force can have a significant force component that preferably acts in the insertion direction (see FIG. 9 (bottom)). The angled stop can be achieved, for example, by chamfered contact surfaces.

[0031] In this case, it may be preferred in connection with the present invention that the contact normal forces form an angle delta with respect to one another that is less than 90 degrees. It is preferred in connection with the present invention that the angle delta between the first contact normal force and the second contact normal force is in an angle range of more than 10 degrees, preferably more than 45 degrees, particularly preferably more than 60 degrees. Thus, preferably, the angle delta is in an angle range of 10-90 degrees, preferably in an angle range of 45-90 degrees, particularly preferably in an angle range of 60-90 degrees. The position of the angle delta can be seen in FIG. 10. Since the angle delta is in one of the aforementioned angle ranges, the second contact normal force can have a significant force component in the insertion direction.

[0032] The variant with the inclined stop can be preferably used when centering of the plug on the blade is desired, in order to prevent the plug from rotating as a result of acceleration, in this way advantageously reducing detrimental relative movements of both contact areas.

[0033] Many interfaces as known from the prior art have only one contact area for transmitting electrical energy and the contact normal forces that occur are perpendicular, i.e. perpendicular, to the insertion direction. As a result, in such interfaces the contact normal forces do not have a significant force component in the insertion direction. In connection with the present invention, having different contact normal forces with different orientations and also a force normal force or a component of the force normal force acting in the insertion direction can improve the current transmission capacity of the proposed interface and at the same time enable a particularly strong and stable connection between the contact counterparts.

[0034] In connection with the present invention, the interface preferably comprises at least one elastic means for reducing the relative movement between the male and female contact counterparts. Furthermore, the elastic means for reducing the relative movement between the contact counterparts may preferably be configured to engage at least one male contact counterpart and / or at least one female contact counterpart. In a particularly preferred exemplary embodiment of the present invention, the elastic means for reducing the relative movement between the power contacts of the interface engages the female contact counterpart. Thus, in this exemplary embodiment of the present invention, for example, at least one female contact counterpart of the interface is present in a spring-mounted manner, and at least one female contact counterpart is further preferably present on the energy supply device. The elastic means for reducing the relative movement is preferably also referred to in connection with the present invention as "elastic spring mounting means". It should be noted that the elastic means of the proposed interface are elastic means for spring mounting the male and / or female contact counterparts. Thus, the present invention departs from the multiple elastic means known from the prior art between the power tool and the interface area of ​​the power tool. It has been found that the spring mounting of the contact counterparts of the interface in combination with force-normal forces of different orientations allows a significant improvement in the current conduction of the interface and the robustness of the connection. This is particularly true when particularly large currents or electrical energy are transmitted at the interface, and more particularly when electrical energy is transmitted for long periods and / or under field conditions, i.e. sometimes with strong vibrations. These advantages are provided in particular by the elastic spring mounting of the contact counterparts in the two spatial directions mentioned above, which can be provided on the one hand by at least one elastic means and on the other hand by the design of the in particular female contact counterpart as a bending contact.

[0035] In connection with the present invention, at least one elastic means for reducing the relative movement between the contact counterparts is preferably configured to generate a bias, the bias being directed substantially perpendicular to the first contact normal force. In this way, support of the bias on the male contact counterpart, in particular on its blade, can be provided via a material with good conductive properties. Preferably, as a result, an integral contact can be formed. Since the components of the female contact counterpart are preferably only supported on the blade of the male contact counterpart in the direction of the bias, the occurrence of relative movements between the at least one female contact counterpart and the at least one male contact counterpart is surprisingly effectively avoided. In other words, the occurrence of relative movements and friction and / or fretting wear (fretting) can be significantly reduced by the present invention and the orientation of the bias being substantially perpendicular to the first contact normal force. Advantageously, the plugging cycle wear, in particular caused by contact normal forces acting substantially perpendicular to the plugging direction of the contact counterparts of the interface, can be significantly reduced in this way, whereby the service life of the contact counterparts of the interface can be significantly extended. In particular, the at least one elastic means presses the female contact counterpart in the direction of the male contact counterpart, so that a particularly tight mechanical contact is formed between the female and male contact counterparts, which exhibits a particularly low contact resistance suitable for transmitting high discharge currents, and surprisingly, a low plug-in cycle wear of the interface is observed at the same time.

[0036] Furthermore, tests have shown that the provision of a bias or at least one resilient means capable of generating a bias provides a particularly tolerance-independent interface for connecting an energy supply device to a power tool. It has further been found that an interface with at least one biased or spring-loaded power contact in combination with at least two contact areas between the power contacts has extremely low loosening and low plug-in wear. The proposed interface is therefore particularly robust against high electrical and mechanical loads. It also has a long service life and is suitable for the transmission of surprisingly large discharge currents or large amounts of charge per unit time. Furthermore, the bias can be directed substantially parallel to the second contact normal force. The resilient means for reducing the relative movement between the contact counterparts can engage one of the contact counterparts involved. In other words, the resilient means for reducing the relative movement between the contact counterparts can engage at least one male contact counterpart or at least one female contact counterpart, the contact counterparts forming a form-fit connection between the power tool and the energy supply device. In other words, the elastic means can engage with one of the contact counterparts, i.e. either the male or female contact counterpart, to form a releasable connection between the power tool and the energy supply device. An essential advantage of the present invention is that particularly high currents can be transmitted by a form-fit connection and, surprisingly, the relative distance between the contact counterparts can be kept particularly short, if not completely reduced to a minimum. In this way, advantageously, the service life of the interface between the power tool and the energy supply device can be significantly extended. In connection with the present invention, the female and male contact counterparts of the interface can also preferably be described as the "power contacts" of the interface.

[0037] By providing at least one elastic means for reducing the relative movement, it is possible to simply compensate for vibrations and shocks acting on the contact counterpart, which may result in relative movement and actual damage of the contact connection between the accumulator battery and the power tool.

[0038] The invention allows, in particular by providing at least one resilient means for reducing the relative movement, to substantially reduce the relative distance between the male and female contact counterparts of the interface, thereby reducing the mechanical friction losses and the current conduction losses between the contact counterparts to a considerable extent. In particular, the invention allows the relative distance between the male and female contact counterparts of the interface to be reduced, for example, to less than 0.3 mm, preferably less than 0.1 mm, particularly preferably less than 0.05 mm.

[0039] The reduction of the relative movements or the shortening of the relative distances of the contacting parts of the interface has several advantageous effects. The first effect concerns the relative movements or the relative distances between the contacting parts which form a form-fit and / or friction-engagement connection between the power tool and the energy supply device. These relative movements or the relative distances may undesirably increase the contact resistance of the interface, which increase is initially independent of the worn state of the interface. In the context of the present invention, this preferably means that an increase in the contact resistance may occur even in the new state of the system composed of the power tool and the energy supply device if an undesirable relative movement of the contacting parts of the interface occurs at the interface between the system components. Furthermore, the contact resistance of the interface may disadvantageously increase further, since the relative movements between the contacting parts may lead to wear and eventually oxidation. In particular wear of the precious metal layers of the contacting parts may occur, which may eventually lead to atmospheric oxidation with atmospheric oxygen and / or fretting wear. Due to the fact that the present invention significantly reduces the relative movements between the contacting parts and therefore the contact resistance, the present invention significantly contributes to achieving that particularly large currents can be transmitted from the energy supply device to the power tool using the proposed interface. Furthermore, the invention reduces unwanted wear of the contact counterparts and thus likewise makes a valuable contribution to extending the service life of the interface.

[0040] In connection with the present invention, it is preferred that the elastic means for shortening the relative distance between the power contacts of the interface brings about a mechanical decoupling between the power tool and the unit made up of male and female contact counterparts. Alternatively, the elastic means may bring about a mechanical decoupling between the power tool and the unit made up of male and female contact counterparts. Due to the mechanical decoupling, undesired relative movements between the contact counterparts are not transmitted and are advantageously compensated by the elastic means.

[0041] Tests have shown that the invention can effectively suppress undesired temperature rises in the contact area between the male and female contact counterparts. For example, the temperature measured in the contact area between the contact counterparts can be reduced by up to 30 degrees, since the grade and quality of the contact between the contact counterparts can be significantly improved by the invention, i.e. by providing elastic means for reducing the relative movement. The improvement of the contact resistance advantageously leads to an increase in the current carrying capacity of the interface, whereby the invention allows the operation of or the supply of electrical energy to higher power class power tools, i.e. especially high power power tools. The reduction of the power losses in the contact resistance can advantageously lead to a reduction of the thermal load of the surrounding components. In particular components made of thermoplastic material can thereby be effectively protected from damage due to the introduction of excessive heat.

[0042] In connection with the present invention, it is preferred that the contact counterpart on which the elastic means for reducing the relative movement act is movably mounted. In other words, the contact counterpart to which the elastic means for reducing the relative movement are operatively connected may be movably mounted. In connection with the present invention, it is further preferred that the movably mounted contact counterpart and / or the movably mounted receiving device are spring mounted. If more than one contact counterpart is provided per connection counterpart of the interface or if the power tool and / or the energy supply device has more than one receiving device, it may be preferred in connection with the present invention that the movably mounted contact counterpart and / or the movably mounted receiving device are spring mounted. In this way, the relative movement and the contact resistance between the contact counterparts can be further significantly reduced and the service life of the interface can be significantly extended. Furthermore, it may be preferred that the elastic means for reducing the relative movement act on the receiving device described below. The receiving device can receive male and / or female power contacts and can be movably mounted as well. The receiving device is movably mounted, in particular when it is operatively connected to at least one resilient means for reducing the relative movement between the power contacts or when said resilient means acts on the receiving device. The statement that the at least one resilient means for reducing the relative movement between the contact counterparts is configured to act on at least one male contact counterpart or on at least one female contact counterpart preferably means that in exemplary embodiments of the invention in which the respective contact counterparts are arranged in the receiving device, the at least one resilient means for reducing the relative movement between the contact counterparts is configured to act on the receiving device in which the respective contact counterparts are accommodated. The receiving device may form a contact block or a contact means block which may be movably mounted or spring-mounted by the resilient means. In the context of the present invention, the receiving device preferably comprises a connection counterpart of the interface, i.e. a contact counterpart of the power tool or of the energy supply device. However, in the context of the present invention, it may also be preferred that several receiving devices are provided, each capable of receiving a partial amount of a contact counterpart of a connection counterpart.Preferably, these several receiving devices may also be spring-mounted by means of elastic means acting on these several receiving devices to reduce relative movements. The receiving devices may thus comprise power contacts, i.e. female and male contact counterparts and / or communication elements. In the context of the present invention, the elastic means for reducing relative movements are preferably also described as "elastic spring mounting means".

[0043] Preferably, the contact counterpart on which the elastic means for reducing the relative movement act is mounted so as to be movable relative to the power tool or the energy supply device in the connected state. If the spring mounting is provided on the power tool side, i.e. if the at least one elastic means acts on a contact counterpart or a receiving device of the power tool, the resulting spring mounting in the area of ​​the power tool preferably contributes to achieving that the corresponding contact counterpart is mounted so as to be movable relative to the power tool in the connected state. If the spring mounting is provided on the energy supply device side, i.e. if the at least one elastic means acts on a contact counterpart or a receiving device of the energy supply device, the resulting spring mounting in the area of ​​the energy supply device preferably contributes to achieving that the corresponding contact counterpart is mounted so as to be movable relative to the energy supply device in the connected state.

[0044] The statement that the elastic means for reducing the relative movement between the contact counterparts is configured to act on at least one male contact counterpart and / or at least one female contact counterpart initially includes the possibility that the elastic means acts on one of the groups of contact counterparts, for example all contact counterparts arranged on the energy supply device or all contact counterparts arranged on the power tool. However, in connection with the present invention it may also be preferred that both the power tool and the energy supply device comprise elastic spring mounting means for their contact counterparts. In this embodiment of the present invention, the elastic means acts on at least one male contact counterpart and at least one female contact counterpart. If one or both groups of contact counterparts are arranged on a receiving device, the elastic means may act on one of the receiving devices. If the contact counterparts of both the energy supply device and the power tool have a receiving device, the elastic means may also act on both receiving devices. The action on both the contact counterpart of the power tool and the contact counterpart of the energy supply device can be achieved, for example, by using a hard spring in one of the connected counterparts, the energy supply device or the power tool, and a soft spring in the other connected counterpart, the power tool or the energy supply device. In the context of the present invention, the term "hard spring" is understood as a spring with a high spring stiffness and the term "soft spring" as a spring with a low spring stiffness.

[0045] In connection with the present invention, it is preferred that at least one male contact mating part is arranged on the power tool. The male contact mating part may comprise a blade that can be inserted into a female contact mating part of the interface or into another system component. According to an advantageous embodiment of the present invention, it may be provided that the male contact mating part is designed as a pin-like plug connector or a blade and the female contact mating part of the interface is designed as a termination with an elastically deformable leg for receiving the pin-like plug connector or the blade. The male contact mating part may be formed by a protruding area and a stopper, the protruding area being inserted into one of the female contact mating parts in the plugged-in state of the interface (hence the "connected state") in which the energy supply device is connected to the power tool. In the non-connected state, the power tool and the energy supply device may be independent and separate from each other. This may be, for example, when the energy supply device is charging and is placed in a charger for charging. In connection with the present invention, it may also be preferred that at least one male contact mating part is arranged on the energy supply device.

[0046] The energy supply device may preferably include at least one storage battery (accumulator), the energy supply device being designed to supply electrical energy to the power tool. The electrical energy is output from the energy supply device to the power tool, in particular in the connected state, when the power tool is connected to the energy supply device via an interface. The female and male contact counterparts engage with each other in the connected state, so that electrical current or electrical energy can flow between the contact counterparts via the contact area. Tests have shown that by using at least one elastic means for reducing the relative movement between the contact counterparts, which engages with one of the contact counterparts, a significantly higher current can be transmitted than when using a conventional contact system, as in the prior art. For example, the present invention allows the transmission of currents in the range of more than 50 Amperes, preferably more than 70 Amperes, particularly preferably more than 100 Amperes.

[0047] The reason why higher currents can flow from the energy supply device towards the power tool with the proposed interface with at least one elastic means is because the energy supply device is decoupled from at least one contact pair of female and male contact counterparts, which is described further below.

[0048] The at least one elastic means for reducing the relative movement may preferably comprise at least one elastic element, such as a spring. Here, the elastic element may be configured in the form of a spring, in particular as a spiral spring, a bending spring or a coil spring. Alternatively, the elastic element may be configured as a component made of an elastically deformable material. In this case, elastomers are also possible materials. It is therefore possible to easily counteract movements associated with vibrations of the connection element, not only in several directions, i.e. towards or away from the connection element. In addition, undesired relative movements between contact counterparts of the interface can be effectively shortened by the use of the elastic element.

[0049] In the context of the present invention, it is preferred that, when inserted into the female contact counterpart, the male contact counterpart compresses the at least one elastic means such that the elastic means is in a stressed state. Alternatively or additionally, the at least one male contact counterpart can also be spring-mounted. In the context of the present invention, the term "spring-mounted" is to be understood to mean that the spring-mounted contact counterpart is operatively connected to an elastic means for reducing the relative movements between the contact counterparts. In other words, the elastic means for reducing the relative movements between the contact counterparts can act on one of the contact counterparts, whereby advantageously a spring mounting of the corresponding contact counterpart is achieved. In the context of the present invention, it is preferred that in the plugged-in state, in which the energy supply device and the power tool are connected together, the at least one elastic means is in a stressed or tensioned state. In the context of the present invention, it is preferred that the elastic means is also biased in the non-installed state, in which the force flow in the energy supply device is closed by said elastic means. Thereby, the at least one female contact counterpart can be supported on the energy supply device. Due to the stress of the at least one elastic means for reducing the relative movement between the contact counterparts, the male and female contact counterparts are reliably pressed against one another, especially when the contact system is in the connected state, so that a particularly good contact is formed between the contact counterparts. Due to this "spring-mounted" contact of the contact counterparts or the particularly tight contact of the contact counterparts, the power density of the resulting contact can be significantly increased, so that it is possible to transmit currents in the range of more than 50 Amperes, preferably more than 70 Amperes or particularly preferably more than 100 Amperes. Likewise, the service life of the proposed contact system can also be substantially extended, so that the proposed contact system is particularly suitable for energy supply devices with a long service life and / or high output currents, since the relatively high mechanical and / or electrical requirements for the interface can be optimally met by the invention.

[0050] In connection with the present invention, it is preferred that at least one female contact partner is arranged on the energy supply device. The at least one female contact partner may preferably be formed by a receiving terminal designed to receive the blade of the male contact partner. For this, the female contact partner may have two legs made of elastic material, which are spread apart on insertion of the male contact partner so that the male contact partner is located inside the female contact partner or the receiving terminal. In connection with the present invention, this situation is referred to as the connected state or inter-insertion state of the interface. Due to the elasticity of the material from which the legs of the female contact partner are formed, the legs of the receiving terminal of the female contact partner in this connected state press against the blade or the protruding area of ​​the male contact partner, whereby a contact area is formed between the contact partners. Preferably, the electric current or electrical energy is exchanged between the contact partners via this contact area, whereby the electric current or electrical energy can flow from the energy supply device towards the power tool. In connection with the present invention, it may also be preferred that at least one female contact partner is arranged on the power tool.

[0051] The legs of the female contact counterpart may preferably comprise or be made from spring steel. As well as spring steel, other metals, metal alloys or plastics with elastic properties can also be used to make the female contact counterpart. Materials with good electrical conductivity, high yield strength and / or low relaxation effect, such as CuFe2P or CuCrSiTi, may be particularly preferred.

[0052] In the context of the present invention, the legs of the female contact counterpart or the receiving terminal preferably have a minimum spacing in the contact area, in order to allow a particularly good contact with the male contact counterpart. In the contact area against the male contact counterpart, the female contact counterpart preferably has a taper defined by the minimum spacing between the legs of the female contact counterpart. In the context of the present invention, the legs of the female contact counterpart preferably comprise copper or are coated with a copper layer in the contact area, in the area of ​​the taper or in the area of ​​the minimum leg spacing. Furthermore, coatings comprising nickel and / or silver can also be used, but are not limited to this. Due to the coating material preferably present in the contact area between the male and female contact counterparts of the proposed interface, the flow of current or the flow of electrical energy from the energy supply device to the power tool can be further optimized, so that in particular high currents, for example 50 amperes, 70 amperes or even more than 100 amperes, can also flow through the interface.

[0053] The energy supply device is removably connected to the power tool via an interface, so that the respective electrical contacts of the power tool and the energy supply device preferably abut against each other in a frictionally engaged manner, whereby the female contact mating part may preferably comprise a resiliently mounted clamp or receiving terminal, while the male contact mating part may have an insertion element that is insertable into the clamp or receiving terminal.

[0054] In connection with the present invention, it is preferred that the at least one elastic means for reducing the relative movement comprises at least one elastic element. Preferably, the male contact mating part and the female contact mating part can form a unit in a connected state, which occurs by inserting the male contact mating part into the female contact mating part. In this embodiment of the present invention, it is preferred that the elastic means for reducing the relative movement between the contact mating parts is operatively connected to the unit of the female contact mating part and the male contact mating part, i.e. engages with one of the contact mating parts of the unit or the interface. In the connected state, the unit of the male and female contact mating parts can be pressed towards the power tool or towards the energy supply device, such that the energy supply device can move independently from the unit of the male and female contact mating parts. This causes the vibration-sensitive unit of the male and female contact mating parts to be decoupled from the energy supply device, and the decoupling of the unit from the energy supply device significantly increases the load-bearing capacity of the interface, its service life and robustness against undesired heating. Surprisingly, by providing at least one elastic means for reducing the relative movement, the male and female contact mating units can be given a movement space, called "play" in the context of the present invention, in which the units can move without colliding with the boundary walls of the movement space. If the male and female contact mating units are mounted in a fixed position relative to the power tool or the energy supply device, the energy supply device can move around the units independently of the units, so that the movements of the energy supply device are decoupled from the contact and vibration sensitive male and female contact mating units.

[0055] Tests have shown that by providing the interface with resilient means for reducing the relative movements, the fretting wear (fretting) between the contact counterparts of the interface can be substantially reduced. In this way, for example, lower quality and cheaper coatings of the contact counterparts can be used, or the use of at least one resilient means for reducing the relative movements leads to a longer service life of the interface and a higher power density, higher power density in the context of the present invention preferably meaning that a higher current can be transmitted through the interface of the male and female contact counterparts.

[0056] Although the present invention cannot prevent undesired movements or vibrations of the energy supply device, at least one elastic means for reducing relative movements advantageously ensures that the pair of male and female contact mating parts of the energy supply device, which are susceptible to contact and vibrations, are decoupled and therefore protected from those movements and vibrations.

[0057] In the context of the present invention, it is preferred that at least one male and one female contact mating form a unit in each case, which in the connected state is decoupled from the movements of the energy supply device. Advantageously, this decoupling of the unit of male and female contact matings with the energy supply device is achieved in particular by at least one elastic means for reducing the relative movements acting on one of the contact matings or on the unit of at least one male and female contact mating. In other words, in the context of the present invention, the elastic means is preferably configured to reduce the relative movements between the contact matings and to act on one of the contact matings or on the unit of the male and female contact matings. Decoupling of the unit from the energy supply device occurs in particular when at least one elastic means for reducing the relative path between the contact matings is present on the energy supply device. However, in the context of the present invention, it may also be preferred if at least one elastic means for reducing the relative distance between the contact matings is present on the power tool. In this case, the unit of male and female contact matings can preferably be decoupled from the power tool.

[0058] In connection with the present invention, it is preferred that the interface comprises 1 to 8, preferably 2 to 6, most preferably 4 female contact counterparts. Preferably, the interface has a corresponding number of male contact counterparts, whereby in each case one male contact counterpart and one female contact counterpart can form a contact pair. In connection with the present invention, it is preferred that the male contact counterparts are arranged on the power tool and the female contact counterparts are arranged on the energy supply device. Naturally, in connection with the present invention, it may also be preferred that the male contact counterparts are arranged on the energy supply device and the female contact counterparts are arranged on the power tool.

[0059] In connection with the present invention, it is also preferred if the interface comprises a receiving device for receiving at least one female contact partner and / or at least one male contact partner. In other words, the receiving device may be configured to receive at least one female contact partner or at least one male contact partner or at least one female and at least one male contact partner. In a preferred exemplary embodiment of the present invention, the receiving device may receive at least one female contact partner. In connection with the present invention, it may be preferred that the female contact partners are individually arranged on the interface or that they are part of the receiving device, the individual female contact partners or the receiving device being components of either the power tool or the energy supply device. In connection with the present invention, it is most preferred that the individual female contact partners or the receiving device are part of the energy supply device.

[0060] The receiving device may form a compartment or cassette capable of receiving female contact counterparts and / or male contact counterparts. In this way a contact block can be advantageously provided, so that the female contact counterparts are or can be moved together. Preferably, the receiving device is capable of receiving 1 to 8, preferably 2 to 6, most preferably 4 female contact counterparts.

[0061] In the context of the present invention, it is preferred that the contact mating parts of the interface are individually spring-mounted or that the contact block formed by the contact mating parts is spring-mounted as a whole. If the contact mating parts are individually spring-mounted, they may be individually operatively connected to elastic means for reducing the relative path. If the interface comprises, for example, four contact mating parts in one of the system elements, i.e. the power tool or the energy supply device, an elastic means or elastic element may be assigned to each of these four contact mating parts. Preferably, in this embodiment of the present invention, this is referred to as "individual spring mounting of the power contacts of the interface". Alternatively, in the context of the present invention, it may be preferred that the entire contact block, preferably including several contact mating parts, female and / or male, is spring-mounted as a whole. In the context of the present invention, such a contact block is also described as a contact means block, and the contact means block may be formed by a receiving device with the power contacts. In the context of the present invention, it is preferred that the contact block or the receiving device is operatively connected to an elastic means or elastic element. This preferably means in connection with the present invention that the elastic means or elastic element is assigned to a contact block or receiving device. Preferably, in this embodiment of the present invention, this is referred to as a "spring-mounted receiving device" or a "spring-mounted contact means block". In connection with the present invention, the interface preferably comprises a communication element for exchanging data between the power tool and the energy supply device. For example, the interface may comprise at least two communication elements, a first communication element being arranged on the power tool and a second communication element being arranged on the energy supply device. The communication elements may be configured to establish a communication link between the power tool and the energy supply device, the communication link being wire-based or wire-free. In other words, the communication link between the power tool and the energy supply device may be of wired or "wireless" design. For example, wireless communication between the power tool and the energy supply device may be based on Bluetooth, WLAN, Zigbee, radio, near-field communication, etc. For example, a transmitter and a receiver may be provided as communication elements.

[0062] In a preferred exemplary embodiment of the invention, the interface comprises four power contacts and two communication elements. The power contacts and the communication elements may be arranged together in a receiving device, with the elastic spring mounting means being associated with a common receiving device. However, it is also preferred in connection with the invention that the power contacts are individually spring mounted and the communication elements have their own communication receiving device. The individual spring mounting of the power contacts of the interface can be provided by elastic means being assigned to the movably mounted power contacts of the interface.

[0063] In connection with the present invention, it may be preferred that the communication element is integrated into the receiving device. In other words, the receiving device may include at least one communication element for transmitting data between the power tool and the energy supply device. In connection with the present invention, the communication element may also preferably be called a "communication plug", especially if the communication connection is wired. In connection with the present invention, it is particularly preferred that the receiving device has two communication elements, which may be preferably arranged centrally in the receiving device. For example, two female contact mating parts may be arranged on one side of the two preferably centrally arranged communication elements, and two female contact mating parts may likewise be present on the other side of the communication elements. The communication elements may be arranged, for example, one above the other.

[0064] In a preferred embodiment of the invention, the power contacts of the interface, i.e. the female and male contact mating parts of the interface, can be spring-mounted separately, while a separate small receiving device is provided for the communication element of the interface, thus forming a separate compartment or cassette for the communication element. The receiving device for the communication element can also be part of the interface between the power tool and the energy supply device.

[0065] In connection with the present invention, it is preferred that at least one elastic means for reducing the relative movements is preferably assigned to the receiving device as a whole. In this case, it is possible, for example, to connect a receiving device, which can receive four female contact counterparts, to the corresponding system component - an electric tool or an energy supply device - by means of an elastic element. A decoupling then takes place, for example, between the energy supply device and / or the electric tool on the one hand and the receiving device on the other hand, whereby the female contact counterparts in the receiving device are decoupled or protected from the movements and / or vibrations of the energy supply device. However, in connection with the present invention, it may also be preferred that a decoupling takes place between the receiving device and the electric tool, whereby the interface can advantageously be decoupled from the movements and / or vibrations of the electric tool as well.

[0066] Tests have shown that by using a compartment as a receiving device for the female contact counterpart, particularly good protection against tilting movements is obtained and the frictional moment between the contacts is particularly well reduced. This advantage of the invention can be achieved by the fact that the support and frictional surfaces of the individual terminal contacts of the female contact counterpart are widely spaced apart from one another transversely or substantially perpendicularly to the insertion direction, so that dynamic tilting moments can be particularly well absorbed by the large lever arm of the mounting part. The same applies to the support surfaces of the contact block, if the female contact counterpart is received by the receiving device. The above statement applies analogously to the male contact counterpart, in particular if the male contact counterpart is received by the receiving device and forms a contact block.

[0067] Alternatively, it may be preferred that at least one resilient means for reducing relative movements is assigned to each contact pair of female and male contact counterparts, in which case, for example, each contact pair of female and male contact counterparts may have its own resilient means for reducing relative movements, such as a resilient element, and may be decoupled or protected from movements and / or vibrations of the energy supply device by the resilient means.

[0068] According to one exemplary embodiment of the invention, elastic means are disclosed that can counteract relative movements between an energy supply device and a power tool. In this case, the energy supply device and the power tool are detachably connected to one another via an interface, which comprises a male contact mating part and a female contact mating part. In particular, the female contact mating parts may be in the form of individual contacts, each female contact mating part being configured to receive a male contact mating part or a blade thereof. Alternatively, the female contact mating parts may form a contact block ("receiving device" or "compartment") that may be part of the energy supply device or the power tool. In the context of the invention, it is particularly preferred that the female contact mating parts are arranged on the energy supply device. However, it may also be preferred that the female contact mating parts are arranged on the power tool. Likewise, the male contact mating parts may be provided in the form of individual contacts, in each case configured to form a contact pair with a female contact mating part having a contact area for the transmission of electrical energy. Alternatively, the male contact mating parts may form a contact block that may be part of the energy supply device or the power tool. It is particularly preferred in connection with the present invention that the male contact counterpart is arranged on the power tool. However, it may equally be preferred that the male contact counterpart is arranged on the energy supply device. The at least one elastic means for reducing the relative movements between the contact counterparts is preferably designed to prevent or reduce the relative movements between the contact counterparts of the interface or the power tool and the energy supply device. The at least one elastic means for reducing the relative movements can here act individually on the male contact counterpart and / or on the female contact counterpart of the interface. However, it may be preferred in connection with the present invention that the at least one elastic means for reducing the relative movements acts on a contact block or a receiving device for the female contact counterpart, which is usually formed by 2 to 8 contact counterparts. The individual female and / or male single contacts or contact blocks formed therefrom can be arranged both on the power tool and on the energy supply device, it being particularly preferred to arrange the female contact counterpart in the area of ​​the energy supply device and the male contact counterpart in the area of ​​the power tool.

[0069] In a second aspect, the invention relates to an interface for transmitting electric energy between a power tool and an energy supply device. The terms, definitions and technical advantages introduced with respect to the system of a power tool and an energy supply device preferably apply to the interface as well. The interface is preferably characterized in that it has at least one male contact mating part and at least one female contact mating part, the female contact mating part and the male contact mating part contact each other at least in a first contact area and in a second contact area, the first contact area being definable by a first contact normal force and the second contact area being definable by a second contact normal force, the first contact normal force and the second contact normal force having different orientations. In connection with the invention, the male and female contact mating parts preferably form a unit in each case, which unit is decoupled from the movement of the energy supply device in the connected state.

[0070] In a further aspect, the present invention relates to an energy supply device for use in the proposed system, preferably an energy supply device having a particularly long service life and / or configured to output a particularly high current, in particular a constant current of more than 50 Amperes, preferably more than 70 Amperes, most preferably more than 100 Amperes.

[0071] The energy supply device may preferably be an accumulator or preferably a rechargeable battery. In connection with the present invention, it is obviously also possible for the energy supply device to have more than one accumulator and / or battery. The accumulator and / or battery may for example comprise a so-called battery pack comprising cylindrical cells. These cylindrical cells may contain, for example, chemicals including but not limited to lithium ions, magnesium ions and / or sodium ions. However, other cell types may be used in connection with the present invention, for example comprising rectangular or cubic cells.

[0072] The energy supply device is preferably an energy supply device with a particularly long service life and / or an energy supply device that is configured to output a particularly high current, in particular a constant current of more than 50 Amperes, preferably more than 70 Amperes, most preferably more than 100 Amperes. A particularly long service life may preferably result in an energy supply device that can withstand a particularly large number of insertion processes or insertion cycles without wearing out. In addition, a particularly long service life may mean that the chemical components of the energy supply device are designed in such a way that they can be charged more frequently than previous energy supply devices without significantly aging. The main advantage of the proposed contact system is that such powerful energy supply devices can be reliably and easily connected. In particular, due to the large number of contact areas between the contact counterparts of the interface, the proposed contact system can transmit high currents and at the same time be used without wearing out throughout the entire service life of the energy supply device. As a result, the advantages of new cell and battery technologies can also be optimally utilized by the present invention. The present invention consequently makes it possible to provide a system consisting of a power tool and an energy supply device, which allows for efficient use of the energy supply device in a battery-powered power tool, particularly for applications and uses which impose very high power and / or very high service life requirements on the system or its interfaces.

[0073] In the context of the present invention, it is preferred that the energy supply device comprises at least one energy storage cell ("cell"), at least one cell having an internal resistance DCR_I of less than 10 milliohms (mOhm). In a preferred configuration of the present invention, the internal resistance DCR_I of the at least one cell may be less than 8 milliohms, preferably less than 6 milliohms. Here, the internal resistance DCR_I is preferably measured according to the standard IEC 61960. The internal resistance DCR_I represents in particular the resistance of the cell of the energy supply device, and the components or accessories of the cell do not contribute to the internal resistance DCR_I. A low internal resistance DCR_I is advantageous because it means that no unnecessary heat is generated that needs to be dissipated. The internal resistance DCR_I is a DC resistance that can be measured in particular inside the cell of the proposed energy supply device. The internal resistance DCR_I can of course also take intermediate values ​​such as 6.02 milliohms, 7.49 milliohms, 8.33 milliohms, 8.65 milliohms or 9.5 milliohms.

[0074] It has been found that with an internal resistance DCR_I of at least one cell of less than 10 milliohms it is possible to provide an energy supply device with particularly good thermal properties, in the sense that it can operate particularly well at low temperatures, and cooling costs can be kept surprisingly low. In particular, energy storage devices with a cell internal resistance DCR_I of less than 10 milliohms are particularly suitable for supplying electrical energy to particularly powerful power tools. Such energy supply devices can therefore make a valuable contribution to enabling the use of battery-powered power tools in fields of use that experts have previously assumed were not open to battery-powered power tools.

[0075] Advantageously, using such an energy supply device it may be possible to supply a battery-powered or accumulator-powered power tool having an energy supply device according to the invention with high levels of output power for extended periods of time without damaging either the surrounding plastic parts or the cell chemistry inside the cells of the energy supply device.

[0076] In the context of the present invention, the ratio of the resistance of the at least one cell to the surface area A of the at least one cell is less than 0.2 milliohms / cm 2 Less than 0.1 milliohms / cm 2 Less than 0.05 milliohms / cm 2 In the case of a cylindrical cell, the surface of the cell may be formed, for example, by the outer surface of the cylinder and the top and bottom surfaces of the cell. Furthermore, in the context of the present invention, the ratio of the resistance of the at least one cell to the volume V of the at least one cell is preferably less than 0.4 milliohms / cm 3 Less than 0.3 milliohms / cm 3 Less than 0.2 milliohms / cm 3 It may be preferable that the resistance is less than 1 / 2. For conventional geometric shapes such as a rectangular parallelepiped, a cube, a sphere, etc., the person skilled in the art knows the formulas for calculating the surface or the volume of such a geometric object. In the context of the present invention, the term "resistance" preferably denotes the internal resistance DCR_I, which can preferably be measured according to the standard IEC 61960. This is preferably the direct current resistance.

[0077] In the context of the present invention, it is preferred that the at least one cell has a heating coefficient of less than 1.0 W / (Ah·A), preferably less than 0.75 W / (Ah·A), particularly preferably less than 0.5 W / (Ah·A). Furthermore, the at least one cell can be designed to output a substantially constant current of more than 1000 Amperes / liter. The discharge current is indicated in relation to the volume of the at least one cell, the volumetric measurement unit "liter" (l) being used as the unit for the volume. The cell according to the invention can therefore output a substantially constant discharge current of more than 1000 A per liter of cell volume. In other words, a cell having a volume of 1 liter can output a substantially constant discharge current of more than 1000 A, the at least one cell further having a heating coefficient of less than 1.0 W / (Ah·A). In a preferred configuration of the present invention, the at least one cell of the proposed energy supply device can have a heating coefficient of less than 0.75 W / (Ah·A), preferably less than 0.5 W / (Ah·A). The units of the heating factor are Watts / (Ampere-hours·Amperes). The heating factor can of course have intermediate values ​​such as 0.56 W / (Ah·A), 0.723 W / (Ah·A) or 0.925 W / (Ah·A).

[0078] The present invention advantageously allows the provision of an energy supply device with at least one cell that exhibits reduced heating and is therefore particularly well suited to supply power tools for which a high power output and a high, preferably constant, current is desired for operation. In particular, the present invention can be used to provide an energy supply device for power tools that can dissipate in a particularly simple and uncomplicated manner the heat that is optionally generated during operation of the power tool and when outputting electrical energy to the power tool. Tests have shown that the present invention can not only be used to more effectively dissipate the heat that is present. Rather, the present invention can suppress the heat generated during operation of the power tool or the amount of heat generated can be significantly reduced using the present invention. The present invention can be advantageously used to provide an energy supply device that can supply electrical energy in an optimal manner even to power tools that have stringent requirements in terms of power and discharge current. In other words, the present invention can provide an energy supply device for particularly powerful power tools that can perform stringent excavation or demolition tasks, for example, on construction sites.

[0079] In the context of the present invention, the term "power tool" is understood to mean a typical device that can be used on a construction site, for example on an architectural and / or civil construction site. Power tools can be, but are not limited to, hammer drills, chisel devices, core drills, angle or cut-off grinders, cutting devices, etc. Furthermore, auxiliary devices such as those sometimes used on construction sites, for example lamps, walkie-talkies, vacuum cleaners, measuring devices, construction robots, wheelbarrows, transport devices, feed devices or other auxiliary devices, can also be "power tools" in the context of the present invention. Power tools can in particular be mobile power tools, and the proposed energy supply device can also be used with stationary power tools, in particular stand-mounted drills or circular saws. However, handheld power tools, in particular battery-powered or battery-powered, are preferred.

[0080] In the context of the present invention, it is preferred that at least one cell has a temperature cooling half-life of less than 12 minutes, preferably less than 10 minutes, particularly preferably less than 8 minutes. In the context of the present invention, this preferably means that the temperature of at least one cell is halved in less than 12, 10 or 8 minutes, due to free convection. The temperature cooling half-life is preferably determined in the non-operating state of the energy supply device, i.e. when the energy supply device is not operating, i.e. when connected to a power tool. It has been found that energy supply devices with a temperature cooling half-life of less than 8 minutes are particularly suitable for use mainly in powerful power tools. The temperature cooling half-life can of course also have values ​​of 8.5 minutes, 9 minutes 20 seconds or 11 minutes 47 seconds.

[0081] Due to the surprisingly low temperature cooling half-life of the proposed energy supply device, the heat generated during operation of the power tool or during charging of the power tool remains in at least one cell for only a short time. In this way, the cell can be recharged particularly quickly and can be quickly reused in the power tool. Moreover, the thermal load on the energy supply device or on the components of the power tool having the proposed energy supply device can be significantly reduced. As a result, the energy supply device can be protected and its service life can be extended.

[0082] In the context of the present invention, at least one cell is preferably arranged in a battery pack of the energy supply device. A series of individual cells can preferably be combined in a battery pack and thus inserted in the energy supply device in an optimal manner. For example, 5, 6 or 10 cells can form a battery pack, and integer multiples of these numbers are also possible. For example, the energy supply device can have individual cell strings that can include, for example, 5, 6 or 10 cells. For example, an energy supply device with three strings of 5 cells can include, for example, 15 individual cells.

[0083] In connection with the present invention, it is preferred that the energy supply device has a capacity of at least 2.2 Ah, preferably at least 2.5 Ah. Tests have shown that the aforementioned capacity values ​​are particularly well suited for the use of powerful power tools in the construction industry and meet the requirements there for the availability of electrical energy and the possible service life of the power tools particularly well.

[0084] At least one cell of the energy supply device is preferably configured to output a discharge current of at least 20 A for at least 10 seconds. For example, the cell of the energy supply device may be designed to provide a discharge current of at least 20 A, in particular at least 25 A, for at least 10 seconds. In other words, at least one cell of the energy supply device may be configured to provide a continuous current of at least 20 A, in particular at least 25 A.

[0085] It is also considered that peak currents, especially short-term currents, can lead to intense heating of the energy supply device. Therefore, an energy supply device with powerful cooling, as can be achieved by the measures described herein, is particularly advantageous. For example, it is considered that at least one cell of the energy supply device can supply at least 50 A for one second. In other words, in the context of the present invention, it is preferred that at least one cell of the energy supply device is configured to supply a discharge current of at least 50 A for at least one second. Power tools may often require high power output for short periods of time. An energy supply device with cells capable of supplying such peak currents and / or such continuous currents may therefore be particularly suitable for powerful power tools, such as those used on construction sites.

[0086] In the context of the present invention, the at least one cell preferably comprises an electrolyte, which is preferably present in a condensed liquid state at room temperature. The electrolyte may comprise, but is not limited to, lithium, sodium and / or magnesium. In particular, the electrolyte may be lithium-based. Alternatively or additionally, the electrolyte may also be sodium-based. It is also conceivable that the accumulator is magnesium-based. The electrolyte-based energy supply device may have a rated voltage of at least 10V, preferably at least 18V, in particular at least 28V, for example 36V. A rated voltage in the range of 18-22V, in particular in the range of 21-22V, is very particularly preferred. The at least one cell of the energy supply device may have, but is not limited to, a voltage of, for example, 3.6V.

[0087] In the context of the present invention, the energy supply device is preferably charged with a charging rate of, for example, 1.5 C, preferably 2 C, most preferably 3 C. A charging rate xC can be understood as meaning the current intensity required to fully charge a discharged energy supply device in the fraction of an hour corresponding to the numerical value x of the charging rate xC. For example, a charging rate of 3 C makes it possible to fully charge the accumulator within 20 minutes.

[0088] In the context of the present invention, at least one cell of the energy supply device preferably has a surface area A and a volume V, the ratio of surface to volume A / V being greater than 6, preferably 8 and particularly preferably 10 times the reciprocal of the cube root of the volume.

[0089] The expression that the surface area A of at least one cell is greater than eight times the cube root of the square of the volume V may also be preferably expressed by the formula A>8*V^(2 / 3). In other words, this relationship may be described in terms of the ratio of the surface area to the volume A / V being greater than eight times the reciprocal of the cube root of the volume.

[0090] To check whether the above relationship is satisfied, the same base unit values ​​must always be used. For example, m for surface area. 2When unit values ​​are used in the above formula, they are preferably m 3 Unit values ​​are used for volume. For example, cm for surface area. 2 When used in the above formula, the value is preferably in units of cm 3 The value is used for the volume. For example, the surface area is expressed in units of mm 2 When used in the above formula, the value is preferably expressed in mm 3 The value is used for the volume.

[0091] For example, cell geometries satisfying the relationship A>8*V^(2 / 3) advantageously have a particularly favorable ratio between the cell's external surface area and the cell volume, which is important for the cooling effect. The inventors have found that the ratio of the surface area to the volume of the at least one cell of the energy supply device has a significant influence on the removal of heat from the energy supply device. An improved cooling capacity of the proposed energy supply device can advantageously be achieved by increasing the cell surface area for a constant volume and low internal resistance of the at least one cell. In connection with the present invention, if the internal resistance of the cell is reduced, a high power output is preferably possible at the same time as a low cell temperature. Reducing the internal resistance of the at least one cell leads to less heat generation. Furthermore, a low cell temperature can be achieved by using cells in which the surface area A of the at least one cell inside the energy supply device is greater than 6 times, preferably 8 times, particularly preferably 10 times the cube root of the square of the volume V of the at least one cell. In particular, this allows for an improved release of heat to the environment.

[0092] It has been found that an energy supply device with cells satisfying the aforementioned relationship can be cooled significantly more effectively than a previously known energy supply device with, for example, cylindrical cells. The aforementioned relationship can be satisfied, for example, by the fact that the cells of the proposed energy supply device have a cylindrical basic shape, but additional elements are arranged on their surface, which increase the surface area. Said elements can be, for example, fins, teeth, etc. Cells that do not have a cylindrical basic shape, but rather have a completely different shape, can also be used within the scope of the present invention. For example, the cells of the proposed energy supply device can have an approximately cuboid or cuboidal basic shape. The term "approximately" is unclear here for the skilled person, since the skilled person knows that, for example, a rectangular prism with recesses or rounded corners and / or edges should also be encompassed by the term "approximately cuboidal" in connection with the present invention.

[0093] In the context of the present invention, it is preferred that at least one cell has a cell core, and there are no points in the cell core that are more than 5 mm away from the surface of the energy supply device. When the energy supply device is discharged, for example when the energy supply device is connected to an electric tool and work is performed with the electric tool, heat can be generated in the cell core. In this particular configuration of the present invention, this heat can be transported in a relatively short path to the surface of the cells of the energy supply device. The heat can be dissipated in an optimal manner from the surface. Such an energy supply device can therefore exhibit good cooling, in particular relatively good self-cooling. The time until a limit temperature is reached can be extended and / or a situation in which a temperature is reached can be advantageously avoided altogether. As a further advantage of the present invention, a relatively uniform temperature distribution can be achieved in the cell core. This can result in a uniform aging of the accumulator. This can therefore extend the service life of the energy supply device.

[0094] In the context of the present invention, it is preferred that at least one cell has a maximum constant current output of more than 50 amps, preferably more than 70 amps, most preferably more than 100 amps. The maximum constant current output is the amount of current that the cell or energy supply device can draw without the cell or energy supply device reaching an upper temperature limit. Possible upper temperature limits can be in the range of 60°C or 70°C, but are not limited thereto. The unit of the maximum constant current output is amperes.

[0095] In the case of all value ranges mentioned in relation to the present invention, all intermediate values ​​should always be considered as disclosed. For example, values ​​from 50 to 70A, i.e., for example, 51, 62.3, 54, 65.55 or 57.06 amps, etc., should also be considered as disclosed for maximum constant current output. Furthermore, values ​​from 70 to 100A, i.e., for example, 72, 83.3, 96, 78.55 or 98.07 amps, should also be considered as disclosed.

[0096] In the context of the present invention, the energy supply device preferably has a discharge C-rate of more than 80·t^(-0.45), where the letter "t" stands for time in seconds. The C-rate advantageously allows the quantification of the charge and discharge currents of the energy supply device, and the discharge C-rate used here allows in particular the quantification of the discharge current of the energy supply device. For example, maximum permissible charge and discharge currents can be indicated by the C-rate. These charge and discharge currents preferably depend on the rated capacity of the energy supply device. An unusually high discharge C-rate of 80·t^(-0.45) advantageously means that the proposed energy supply device can be used to achieve particularly high discharge currents required for operating powerful power tools in the construction industry. For example, the discharge currents can be in the region of more than 50 amperes, preferably more than 70 amperes, even more preferably more than 100 amperes.

[0097] In the context of the present invention, it is preferred that the cells have a cell temperature gradient of less than 10 Kelvin. The cell temperature gradient is preferably a measure of the temperature difference within at least one cell of the proposed energy supply device, and in the context of the present invention it is preferred that the cells have as homogeneous a temperature distribution as possible, i.e. the temperature in the inner area of ​​the cell differs as little as possible from the temperature measured in the lateral or outer area of ​​the cell.

[0098] Further advantages will become apparent from the following description of the figures. The figures, the specification and the claims include a number of feature combinations. Those skilled in the art will also consider the features individually and combine them as appropriate to form further useful combinations.

[0099] In the figures, identical and similar components are designated with the same reference numerals. [Brief description of the drawings]

[0100] [Figure 1] 1 shows a preferred embodiment of a system consisting of a power tool and an energy supply device. [Diagram 2] 1 shows a possible embodiment of the upper surface of the energy supply device of a preferred embodiment of the proposed system. [Diagram 3] 1 shows a possible embodiment of a unit made up of female and male contact counterparts. [Figure 4] 1 shows a possible embodiment of an interface consisting of a female contact mating part and a male contact mating part with two contact areas. [Diagram 5] 1 shows different views of the male and female contact mates in the connected state. [Figure 6] 1 shows different views of the male and female contact mates in the separated state. [Figure 7] FIG. 2 shows a detailed view of a preferred embodiment of the female contact mate. [Figure 8] FIG. 2 shows a detailed view of a preferred embodiment of a male contact mate. [Figure 9]FIG. 2 shows a detailed view of a pair of male and female contact mates with different orientations of the contact normal forces. [Figure 10] 1 shows a representation of the angle delta between a first contact normal force and a second contact normal force. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0101] FIG. 1 shows a possible embodiment of a system 100 of a power tool 10 and an energy supply device 20. In the exemplary embodiment of the invention shown in FIG. 1, the power tool 10 is shown in the left half of the image and the energy supply device 20 is shown in the right half of the image. The power tool 10 has two male contact mating parts 50, in particular a blade 52 is shown in FIG. 1. The male contact mating parts 50 are part of an interface 30, which also has a female contact mating part 40. In the exemplary embodiment of the invention shown in FIG. 1, the female contact mating part 40 is arranged on the energy supply device 20. The female contact mating part 40 may constitute an individual contact or may be integrated in a block or compartment as shown in FIGS. 1 and 2. The block or compartment with the female contact mating part 40 is described as a receiving device 80 (see FIG. 2). FIG. 1 shows in particular the case where the power tool 10 and the energy supply device 20 are separated from each other. The power tool 10 and the energy supply device 20 may together form a system 100, the energy supply device 20 being configured to supply electrical energy to the power tool 10. In addition, the interface 30 comprises elastic means 60 for reducing the relative distance between the male contact mating part 50 and the female contact mating part 40. At least one elastic means 60 may comprise an elastic element 62, which may be, for example, a spring or a spiral spring. However, all other conceivable elastic elements 62 are possible and conceivable. When the male contact mating part 50 is introduced into the female receiving terminal 40, the elastic means 60 for reducing the relative distance is compressed so that a particularly stable contact is formed between the contact mating parts 40, 50. Such a contact is shown in FIG. 3. The contact of the contact mating parts 40, 50 and the compression of the elastic means 60 for reducing the relative distance creates a play or movement space in which a unit 70 (see FIG. 3) of the male contact mating part 50 and the female contact mating part 40 may be present. The movement or vibration of the energy supply device 20 then leads to the unit 70 of the male contact mating part 50 and the female contact mating part 40 having sufficient play not to collide with the boundary wall of the movement space.The energy supply device 20 is therefore decoupled from the unit 70 of the male contact mating part 50 and the female contact mating part 40, whereby the unit 70 of the male contact mating part 50 and the female contact mating part 40 is particularly well protected. A stable contact between the contact mating parts 40, 50 means that particularly high currents can flow from the energy supply device 20 to the power tool 10. This is achieved because in particular the contact resistance between the contact mating parts 40, 50 can be substantially reduced by the invention, so that also the temperature, measured in particular in the contact area 32 (see FIG. 3 ) between the contact mating parts 40, 50, does not rise much more than in conventional interfaces as known from the prior art. Due to the reduced contact resistance and the reduced temperature in the contact area 32 of the interface 30, the service life of the proposed interface 30 is satisfactorily extended.

[0102] 1 shows that the male contact mating part 50 is arranged on the power tool 10 and the female contact mating part 40 is arranged on the energy supply device 20, the reverse arrangement may also be possible, in which the male contact mating part 50 is arranged on the energy supply device 20 and the female contact mating part 40 is arranged on the power tool 10. In particular, in the context of the present invention, it may be preferred that the male contact mating part 50 is spring mounted, i.e. connected to elastic means 60 for reducing the relative distance.

[0103] An insertion direction 34 is shown in the figure, which indicates the direction in which the contact mating portions 40, 50 of the interface 30 are inserted or pushed together to form a conductive connection.

[0104] 2 shows a possible embodiment of the top view of the energy supply device 20 of a preferred embodiment of the proposed system 100. This figure shows four female contact mates 40 arranged in a receiving device 80. In an exemplary embodiment of the invention not shown, the receiving device 80 may also receive male contact mates 50 or male contact mates 50 and female contact mates 40. The receiving device 80 is especially configured to receive the power or current contacts 40, 50 of the interface 30.

[0105] The interface 30 may include a communication element 90, which may be arranged, for example, in the region of the receiving device 80 or may be a component of the receiving device 80. The communication element 90 may be arranged centrally or centrally in the receiving device 80 and may be provided for transmitting data between the power tool 10 and the energy supply device 20. Furthermore, in FIG. 2 two elastic elements 62 formed as springs, in particular as spiral springs, are shown. The springs 62 form a means 60 for reducing the relative distance between the current or power contacts 40, 50 of the interface 30. The communication elements 90 may be designed to establish a communication link 92 between the power tool 10 and the energy supply device 20, which may be of wired or wireless design. The communication link 92 is indicated diagrammatically in FIG. 1 by a dashed line between the communication elements 90.

[0106] The receiving device 80 may further comprise communication elements 90, which are preferably arranged in the center or centre of the receiving device 80. The communication elements 90 are preferably provided for transmitting data between the power tool 10 and the energy supply device 20. Furthermore, in Fig. 2 two elastic elements 62 are shown, which are designed as springs, in particular as spiral springs. The springs 62 form the means 60 for reducing the relative distance.

[0107] Fig. 3 shows a further possible embodiment of a unit 70 of a female contact mating part 40 and a male contact mating part 50. Fig. 3 shows an interface 30 in particular with a female contact mating part 40 and a male contact mating part 50. In particular, Fig. 3 shows a connected state in which the energy supply device 20 and the power tool 10 are connected to each other such that a current or electrical energy can flow from the energy supply device 20 towards the power tool 10. The blade 52 of the male contact mating part 50 is arranged in the receiving terminal 44 or the leg 44 of the female contact mating part 40, the contact mating parts 40, 50 together form a contact area 32 via which a current or electrical energy can be transmitted from the energy supply device 20 to the power tool 10. The contact area 32 is formed in particular in the region of the taper 42 of the female contact mating part 40, the components of the leg 44 or the receiving terminal 44 of the female contact mating part 40 being at a minimum distance from each other. Thus, the legs 44 of the female contact 40 are located particularly close to the blades 52 of the male contact 50. In the context of the present invention, the contact area 32 preferably represents a first contact area 110. A first contact normal force 112 is directed substantially perpendicular to the insertion direction 34 at the first contact area 110 of the interface 30.

[0108] FIG. 4 shows a further possible embodiment of a unit 70 of female contact counterparts 40 and male contact counterparts 50. FIG. 4 shows an interface 30 including in particular power contacts 40, 50, at least one female contact counterpart 40 being spring-mounted or biased with elastic means 60 for reducing the relative distance between the contact counterparts 40, 50. The blade 52 of the male contact counterpart 50 is received by an interior 48 of the female contact counterpart 40, this interior 48 being formed by the legs 44 of the female contact counterpart 40. The contact between the contact counterparts 40, 50 is present in a contact area 32 of the interface 30, which in the exemplary embodiment of the invention shown in particular in FIG. 4 is located in the area of ​​minimum distance between the legs 44 of the female contact counterpart 40. This contact area 32 is preferably also referred to in connection with the invention as a first contact area 110. A first contact normal force 112 is shown in FIG. 4 with arrows pointing towards each other. The first contact normal force 112 is preferably substantially perpendicular to an imaginary central axis passing through the blade 52 of the male contact partner 50. The first contact normal force 112 may further be formed substantially perpendicular to a second contact normal force 122 defined by the second contact area 120 of the interface 30. In an exemplary embodiment of the invention shown in FIG. 4, the first contact normal force 112 is directed substantially perpendicular to the insertion direction 34 of the interface 30 and the second contact normal force 122 is directed substantially parallel to the insertion direction 34 of the interface 30.

[0109] The second contact area 120 can be formed by the stop 49 of the female contact mating part 40 and the contact surface 56 of the male contact mating part 50. Preferably, the second contact area 120 between the contact mating parts 40, 50 is formed by the contact surfaces 49, 56, the female contact mating part 40 having the contact surface 49 and the male contact mating part 50 having the contact surface 56. In the connected state of the contact mating parts 40, 50 shown in FIG. 5, the contact surfaces 49, 56 of the contact mating parts 40, 50 are oriented substantially perpendicular to the insertion direction 34. The contact surfaces 49, 56 can be represented by surface normals, which in the exemplary embodiment of the invention shown in FIG. 5 are oriented substantially parallel to the insertion direction 34. A second contact normal force 122 acts between the contact surfaces 49, 56 of the contact mating parts 40, 50, which is preferably oriented substantially parallel to the insertion direction 34. The direction in which the second contact normal force 122 acts is indicated by a black arrow in the partial FIG. 5b). Preferably, the second contact normal force 122 is directed substantially perpendicular to the first contact normal force 112. Electric current can be transferred from one contact counterpart 40, 50 to the other contact counterpart 50, 40 in both the first contact area 110 and the second contact area 120 of the interface 30. Tests have shown that the transfer of electric current is particularly loss-free, which is due to the close contact between the contact counterparts 40, 50 of the interface 30. The transfer of electric current is further improved if at least one of the contact counterparts 40, 50 of the current conductor pair 70 or the pair 70 of power contacts 40, 50 is spring-mounted.

[0110] In the exemplary embodiment of the invention shown in figures 5 and 6, the female contact mating part 40 has two stops 49. In the context of the invention, it is preferable that these two stops 49 are as far apart as possible, since this improves the mechanical stability of the interface 30. In particular, the maximum possible distance between the stops 49 of the female contact mating part 40 effectively prevents undesired tilting of the interface 30, which may impair its current-carrying ability. The blade 52 of the male contact mating part 50 protrudes into the interior 48 of the female contact mating part 40, but does not abut anywhere. The pointed or wedge-shaped configuration of the front area 54 of the blade 52 of the male contact mating part 50 is preferably intended to spread the contact legs 44 of the female contact mating part 40 so that the blade 52 of the male contact mating part 50 can slide into the interior 48 of the female contact mating part 40 as easily as possible. The contact surface 47 of the female contact mating part 40 is preferably designed to provide a relative distance between the contact mating parts 40 , 50 of the interface 30 .

[0111] FIG. 5 shows different views of the male contact mating part 50 and the female contact mating part 40 in a connected state. Partial FIG. 5a shows a side view of the unit 70 consisting of the female contact mating part 40 and the male contact mating part 50, and partial FIG. 5b shows a top view of the unit 70 consisting of the female contact mating part 40 and the male contact mating part 50. The female contact mating part 40 can be present in a connected state to a current conductor 36, which can be connected, for example, to an energy storage cell of the energy supply device 20 in order to conduct a current or energy in the direction of the interface 30. The current conductor 36 can be formed, for example, by a braided wire. The male contact mating part 50 can preferably be arranged on the power tool 10 or can be a part of the power tool 10. In particular, the male contact mating part 50 can be designed to receive a current or energy via its blade 52 when the male contact mating part 50 and the female contact mating part 40 are connected to each other, as shown in FIG. 5. The blade 52 of the male contact mating part 50 may be received in the interior 48 of the female contact mating part 40 and may be in contact with the components of the female contact mating part 40 at two locations 110, 120. In the context of the present invention, these contact locations 110, 120 are called the first contact area 110 and the second contact area 120. The first contact area 110 is in the region of the taper 42 of the leg 44 of the female contact mating part 40. In this region of the taper 42, the leg 44 of the female contact mating part 40 is pressed against the blade 52 of the male contact mating part 50, so that a first contact normal force 112 may act between the contact mating parts 40, 50. This first contact normal force 112 is preferably directed substantially perpendicular to the insertion direction 34 of the contact mating parts 40, 50 facing each other. The direction in which the first contact normal force 112 acts is indicated by a black arrow in partial FIG. 5b). The insertion direction 34 preferably corresponds to the direction in which the blade 52 of the male contact part 50 can be inserted into the contact arm 44 of the female contact part 40 in order to connect the contact parts 40, 50 of the interface 30. Figures 5 and 6 show a pair 70 of a male contact part 50 and a female contact part 40, respectively. In the context of the present invention, the interface 30 or its connection parts 10, 20 preferably comprises two or more contact pairs 70.For example, the power tool 10 and / or the energy supply device 20 may each include four contact mating parts 40, 50. Furthermore, these contact mating parts 40, 50 may be present in a state arranged in a receiving device 80 (see FIG. 1).

[0112] In an exemplary embodiment of the invention shown in Fig. 5, one female contact mating part 40 is spring mounted. This means that the female contact mating part 40 is connected to a spring mounting means 60, which can be, for example, a spring 62 or other elastic means 62. In the connected state of the contact mating parts 40, 50 shown in Fig. 5, the elastic spring mounting means 60 is in a compressed or pressed state. As a result, the unit 70 consisting of the contact mating parts 40, 50 is biased, which leads to the decoupling of the unit 70. Fig. 5 therefore shows a single spring mounted female contact mating part 40.

[0113] The female contact mating part 40 may further comprise a stopper 49 which can cooperate with the contact surface 56 of the male contact mating part 50. This allows to increase the stability of the connection between the contact mating parts 40, 50. In the side view of the contact mating pair 70 shown in the partial FIG. 5a), two stoppers 49 of the female contact mating part 40 are shown, a first or upper stopper 49 being arranged on the upper side of the female contact mating part 40 and a second or lower stopper 49 being arranged on the lower side of the female contact mating part 40. If the female contact mating part 40 has two stoppers 49, it is preferred in connection with the present invention that these stoppers 49 are as far apart as possible. By providing the stopper 49 which cooperates with the contact surface 56 of the male contact mating part 50, the tilting of the contact mating parts 40, 50 relative to each other can be effectively suppressed. As can be seen from partial FIG. 6 a), the contact surface 56 can have a ramp 59 for guiding the stopper 49 in order to guide the contact mating parts 40, 50 towards each other when establishing a connection between the contact mating parts 40, 50 so that no damage occurs to the contact mating parts 40, 50.

[0114] Fig. 6 shows different views of the male contact part 50 and the female contact part 40 in a separated state, i.e. the contact parts 40, 50 are not connected to each other and are present separately. Partial Fig. 6a shows a side view of a unit 70 consisting of the female contact part 40 and the male contact part 50, and partial Fig. 6b shows a top view of the unit 70 consisting of the female contact part 40 and the male contact part 50. The male contact part 50 is shown on the left side of Fig. 6 and the female contact part 40 is shown on the right side of Fig. 6. The male contact part 50 comprises a blade 52 for insertion into the female contact part 40 and a contact surface 56 with a ramp 59. The blade 52 of the male contact mating part 50 and the contact leg 44 of the female contact mating part 40 preferably form a first contact area 110 in connection with the present invention, and the stopper 49 of the female contact mating part 40 and the contact surface 56 of the male contact mating part 50 form a second contact area 120. A second contact normal force 122 acts on the second contact area 120 and is preferably oriented substantially parallel to the insertion direction 34 of the interface 30. The direction in which the second contact normal force 122 acts is indicated by a black arrow in FIG. 6b). It is preferred in connection with the present invention that the stopper 49 and the contact surface 56, in particular the surfaces which constitute them, are oriented substantially perpendicular to the insertion direction 34 of the interface 30. In other words, it is possible to define a surface normal of the contact surfaces 49, 56 which is oriented substantially parallel to the insertion direction 34, this surface normal being oriented substantially perpendicular to the contact surfaces 49, 56.

[0115] A first contact area 110 may be formed by the contact arm 44 of the female contact mating part 40 and the blade 52 of the male contact mating part 50. In this first contact area 110 a first contact normal force 122 acts, which is preferably directed substantially perpendicular to the insertion direction 34 of the interface 30. The direction in which the first contact normal force 112 acts is indicated by a black arrow in FIG. 6b).

[0116] In the exemplary embodiment of the invention shown in Fig. 6, the female contact mating part 40 is present in a spring-mounted state, i.e. it is connected to a resilient means 60, which is in a relaxed state in Fig. 6, i.e. the spring 62 or the resilient means 62 of the resilient spring mounting means 60 is present in a non-compressed state. The female contact mating part 40 shown in Fig. 6 may be a component of the energy supply device 20, which may be connected to other components of the energy supply device 20 via a current conductor 36. The current conductor 36 may be formed as and / or may include a braided wire.

[0117] FIG. 7 shows a detailed view of a preferred embodiment of the female contact mating part 40. The embodiment of the female contact mating part 40 shown in FIG. 7 has two contact arms 44 on either side, into which a blade 52 of a male contact mating part 50 (not shown in FIG. 7) can be inserted. The blade 52 of the male contact mating part 50 and the contact arm 44 of the female contact mating part 40 can form a first contact area 110 of the interface 30. The female contact mating part 40 shown in FIG. 7 is connected to a resilient spring mounting element 60, so that the female contact mating part 50 is preferably spring mounted. In particular, FIG. 7 shows a stopper 49, which can form a second contact area 120 of the interface 30 with a contact surface 56 of the male contact mating part 50 (not shown in FIG. 7). Electric current can flow through the contact areas 110, 120 of the interface 30, and thus electrical energy can be transmitted from one contact mating part 40, 50 to the other contact mating part 50, 40. The current carrying areas of the contact areas 110, 120 of the interface 30 are shown in particular in Fig. 8. The stops 49 are spaced as far apart as possible to allow the most stable possible mechanical connection between the contact counterparts 40, 50. In particular, the distance is substantially perpendicular to the direction of the first contact normal force 112 and substantially perpendicular to the insertion direction 34 of the interface 30. The maximum possible distance between the stops 49 ensures in particular that the interface 30 is particularly well protected against tilting movements.

[0118] FIG. 8 shows a detailed view of a preferred embodiment of the male contact mating part 50. The male contact mating part 50 shown in FIG. 8 comprises a blade 52 having a front region 54 and upper and lower contact surfaces 56. The contact surfaces 56 may cooperate with the stopper 49 of the female contact mating part 40 (not shown in FIG. 8) to form a second contact region 120. When the interface 30 is in the connected state, the blade 52 of the male contact mating part 50 projects into the interior 48 of the female contact mating part 40 without contacting any component of the female contact mating part 40. The front region 54 of the blade 52 of the male contact mating part 50 is preferably tapered or wedge-shaped in order to spread the contact arms 44 of the female contact mating part 40 when the contact mating parts 40, 50 are connected, making it particularly easy to insert the blade 52 into the interior 48 of the female contact mating part 40.

[0119] The hatched areas of the blade 52 of the male contact mate 50 shown in Figure 8 are "held" by the contact arms 44 of the female contact mate 40 when the interface 30 is connected, thereby forming a first contact area 110 between the contact mates 40, 50. It is preferred in connection with the present invention that electrical current can flow through both contact areas 110, 120, and these areas through which electrical current passes are shown hatched in Figure 8.

[0120] The male contact part 50 may also include a ramp 59, which serves to guide the stop 49 of the female contact part 40 and the contact surface 56 of the male contact part 50 towards each other.

[0121] FIG. 9 shows a detailed view of a pair 70 of a male contact mating part 50 and a female contact mating part 40 with different orientations of the contact normal forces 112, 122. In the upper half of FIG. 9, the first force normal force 112 is preferably directed substantially perpendicular to the insertion direction 34, and the second force normal force 122 is directed substantially parallel to the insertion direction 34. The quarter-circle arc between the arrows intended to symbolize the contact normal forces 112, 122 indicates the right angle existing between the contact normal forces 112, 122. In the case of a "straight stopper" as shown in the upper half of FIG. 9, the second force normal force 122 acts substantially entirely in the direction of the insertion direction 34. Since the female contact mating part 40 typically has a leg 44 with a taper 42 that can press the blade 52 of the male contact mating part 50 from multiple spatial directions, two first force normal forces 112_1 and 112_2 acting on the blade 52 from different spatial directions are symbolically shown in the upper half of Figure 9 for the first force normal force 112.

[0122] In the lower half of FIG. 9, the second force normal force 122 forms an angle delta with the first force normal force 112 (see FIG. 10). The second force normal force 122 can be projected into the insertion direction 34 by a projection P, symbolized by a downward dashed vertical arrow in the lower half of FIG. 9, resulting in a significant force component 122_wK of the second force normal force 122. The dominant force component 122_wK represents the component of the second force normal force 122 acting in the insertion direction 34. The magnitude of this component, i.e. the magnitude of the dominant force component 122_wK of the second force normal force 122, preferably depends on the angle delta. The smaller the angle delta, the smaller the dominant force component 122_wK of the second force normal force 122, i.e. the smaller the component of the second force normal force 122 acting in the insertion direction 34. The main force component 122_wK of the second force normal force 122 is indicated in the lower half of FIG. 9 by a thick dashed horizontally extending arrow pointing leftwards, which is substantially parallel to the insertion direction 34 and substantially perpendicular to the projection P.

[0123] In particular, the lower half of FIG. 9 shows a "tilted stop", where the blade 52 of the male contact mating part 50 meets the inclined contact surface 125 of the female contact mating part 40. The inclined position of the contact surface 125 of the female contact mating part 40 results in an inclined position of the second force-normal force 122, which causes a reduced second force-normal force 122_wK to act in the insertion direction 34. In the context of the present invention, the phrase "reduced second force-normal force 122_wK" preferably means that the main force component 122_wK in the insertion direction 34 is always smaller than the second force-normal force 122 that would result if the force-normal forces 112, 122 were perpendicular to each other as in the upper half of FIG. 9. It has been shown that an interface with two force-normal forces acting in different directions is particularly suitable for transmitting electrical energy and high currents under harsh working conditions, such as on a construction site.

[0124] FIG. 10 shows a representation of the angle delta between the first contact normal force 112 and the second contact normal force 122. The angle delta is shown by the arc formed between the first force normal force 112 and the displacement 122* of the second force normal force 122. The displacement 122* of the second force normal force 122 is symbolized by a dashed arrow running diagonally downwards, the tip of which coincides with the tip of the first contact normal force 112 and forms the apex of the angle delta. The displacement path to obtain the displacement 122* of the second force normal force 122 is symbolized in FIG. 10 by a horizontal arrow drawn between the displacement 122* and the second force normal force 122 and pointing to the left. The angle between the first force normal force 112 and the displacement 122* of the second force normal force 122 preferably corresponds to the angle delta between the first force normal force 112 and the second force normal force 122. A first force normal force 112 acts on the first contact area 110 and a second force normal force 122 acts on the second contact area 120 . [Explanation of symbols]

[0125] 10 Power tools 20 Energy supply device 30 Interface 32 Contact area 34 Insertion direction 36 Current Conductor 40 Female contact mating part 42 Taper 44 Female contact mating part leg 46 Protruding area / pedestal of female contact mating part 47 Contact surface of female contact mating part 48 Inside of female contact mating part 49 Female contact mating part stopper 50 Male contact mating part 52 Blade 54 Front area of ​​male contact mating part 56 Contact surface of male contact mating part 59 ramp 60 Measures to reduce relative movement 62 Elastic Elements 70 Female and male contact mating units 80 Receiving Equipment 90 Communication Elements 92 Communication Links 100 Systems 110 first contact area 112 First Contact Normal Force 120 Second Contact Area 122 Secondary Contact Normal Force 125 Inclined contact surface of female contact mating part

Claims

1. A system (100) including an electric power tool (10) and an energy supply device (20) for supplying electric energy to the electric power tool (10), the energy supply device (20) being detachably connectable to the electric power tool (10) via an interface (30), the interface (30) including at least a female contact mating part (40) and a male contact mating part (50). and the male contact counterpart (50) contact each other at least at a first contact area (110) and a second contact area (120), the first contact area (110) can be defined by a first contact normal force (112) and the second contact area (120) can be defined by a second contact normal force (122), the first contact normal force (112) and the second contact normal force (122) having different orientations.

2. The system (100) of any of the preceding claims, wherein the first contact normal force (112) and the second contact normal force (122) are oriented substantially perpendicular to one another.

3. 3. The system (100) according to claim 1 or 2, characterized in that one of the contact normal forces (112 and / or 122) in the case of connection is directed substantially perpendicular to the insertion direction (34) of the interface (30) and / or the other contact normal force (122 and / or 112) in the case of connection is directed substantially parallel to the insertion direction (34).

4. The system (100) according to any one of claims 1 to 3, characterized in that the second contact area (120) includes a stopper (49) and a contact surface (56), the stopper (49) and the contact surface (56) being oriented substantially perpendicular to an insertion direction (34) of the interface (30).

5. A system (100) according to any one of the preceding claims, characterized in that a front region (54) of the male contact partner (50) is flat so as to form a contact surface (56).

6. 2. The system (100) according to claim 1, characterized in that the first contact normal force (112) and the second contact normal force (122) form an angle delta with respect to each other, the angle delta being in an angular range of 10 to 90 degrees, preferably in an angular range of 45 to 90 degrees, particularly preferably in an angular range of 60 to 90 degrees.

7. The system (100) according to any one of claims 1 to 6, characterized in that the interface (30) comprises at least one elastic means (60) for reducing the relative movement between the contact counterparts (40, 50), the elastic means (60) for reducing the relative movement between the contact counterparts (40, 50) being designed to act on the at least one male contact counterpart (50) or on the at least one female contact counterpart (40).

8. The system (100) according to any one of claims 1 to 7, characterized in that the at least one elastic means (60) for reducing the relative movement between the contact counterparts (40, 50) is configured to generate a biasing force, the biasing force being directed substantially perpendicular to a first contact normal force (112).

9. 9. A system (100) according to claim 7 or 8, characterized in that the contact counterpart (40 or 50) on which the elastic means (60) for reducing the relative movement act is movably mounted.

10. A system (100) according to any one of claims 1 to 9, characterized in that the male contact mating part (50) and the female contact mating part (40) in each case form a unit (70) which, in the connected state, is decoupled from the movement of the energy supply device (20) and / or the power tool (10).

11. The system (100) according to any one of claims 1 to 10, characterized in that the interface (30) comprises a receiving device (80) for receiving at least one female contact mating part (40) and / or at least one male contact mating part (50).

12. A system (100) according to any one of claims 1 to 11, characterized in that the at least one elastic means (60) for reducing the relative movement is assigned to the receiving device (80) or that the at least one elastic means (60) for reducing the relative movement is assigned to each contact pair of a female contact mating part (40) and a male contact mating part (50).

13. An interface (30) for transmitting electrical energy between an electric power tool (10) and an energy supply device (20), comprising at least one male contact mating part (50) and at least one female contact mating part (40) and at least one elastic means (60) for reducing relative movement between said contact mating parts (40, 50), wherein said female contact mating part (40) and said male contact mating part (50) are in contact with each other at least in a first contact area (110) and a second contact area (120).

14. An energy supply device (20) for use in a system according to any one of claims 1 to 12, comprising at least one energy storage cell, the at least one energy storage cell having an internal resistance DCR_I of less than 10 milliohms.

15. 13. An energy supply device (20) for use in a system according to any one of claims 1 to 12, comprising at least one energy storage cell, said at least one energy storage cell having a surface area A and a volume V, said surface area to volume ratio A / V being greater than 6 times, preferably 8 times, particularly preferably 10 times the reciprocal of the cube root of said volume.

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