Patent Application
20120171539
The present application claims priority to and the benefit of German patent application no. 10 2011 002 404.2, which was filed in Germany on Jan. 3, 2011, the disclosure of which is incorporated herein by reference.
The present invention relates to a handheld machine tool energy supply unit.
Handheld machine tool energy supply units are known, particularly battery or accumulator packs, having an accumulator unit and an interface element.
The exemplary embodiments and/or exemplary methods of the present invention relate to an handheld machine tool energy supply unit, particularly a battery pack or accumulator pack having an accumulator unit and an interface element. By “handheld machine tool energy supply unit” one should particularly understand a unit provided to supply an handheld machine tool especially with electrical energy. One may understand by this a battery pack or accumulator pack. In a particular manner, the handheld machine tool energy supply unit is implemented as a unit that is exchangeable by the user, which is connected to an handheld machine tool via an interface. The handheld machine tool energy supply unit may include an accumulator unit that contains one or more battery or accumulator cells, and an interface unit using which the handheld machine tool energy supply unit is connected mechanically or electrically to an handheld machine tool. By “handheld machine tool” one should understand particularly a machine processing a workpiece, such as, in particular, a drilling machine, a hammer drill, a percussion drill, a saw, such as a compass saw or saber saw, a screwdriver, a milling machine, a grinder, an angle sander, an orbital sander, a gardening tool and/or a multifunctional tool, etc.
It is provided that the handheld machine tool energy supply unit include a damping unit which is provided for supporting the accumulator unit in a vibration-damped manner. By “damping unit” one should understand a unit that is suitable for clearly reducing the transmission of an oscillation and/or vibration from the handheld machine tool and/or parts of the handheld machine tool energy supply unit to the accumulator unit. The damping unit includes damping and/or spring elements which clearly lessen the accelerations acting on the accumulator unit. By “clearly reduce” it should be understood that, particularly, the maximum acceleration of the oscillation or vibration, that is acting on the accumulator unit, is reduced by at least 50%, which may be by more than 80%. The damping unit may transform a part of the oscillating energy into heat, by having an entropy-elastic behavior. In response to alternating stress by oscillation or vibration, the damping unit may demonstrate hysteresis, that is, in the stress-expansion diagram, the loading curve does not correspond to the unloading curve. Because of the conversion of mechanical oscillation energy into heat, a part of the kinetic energy is absorbed. It may advantageously be achieved that the accumulator unit is protected from oscillation or vibration of the handheld machine tool. The mechanical robustness can be increased. The sensitive battery or accumulator cells of the accumulator unit can be treated with care. The service life and the reliability of the handheld machine tool energy supply unit can be increased. Wear can be reduced. Safety is able to be improved. In particular, the risk of a short circuit of a battery cell or an accumulator cell or of the accumulator unit is able to be reduced.
The damping unit may connect the accumulator unit to the interface element in a damped manner. By this one should particularly understand that the accumulator unit is supported in a damped manner by the damping unit in the interface element and/or, in at least one operating state, a supporting force of the accumulator unit is supported via the damping unit on the interface element. The damping unit may be the only connection between the accumulator unit and the interface element. However, there may also be provided additional connections between the interface element and the accumulator unit. In particular, safety elements may be provided which prevent the accumulator unit from becoming detached from the interface element. Safety elements may be configured to be flexurally soft, and do not transmit any substantial oscillation or vibration from the interface element to the accumulator unit. Safety elements may be developed as wires or cords, for example. An advantageous oscillation damping of the accumulator unit may be achieved. Because of the supporting of the accumulator unit by the damping unit, component parts may be saved.
Furthermore, it is provided that the damping unit is at least partially developed from an elastomeric material. By “elastomeric material” one should understand an entropy-elastic elastomeric material having a distinct hysteresis, which is used above its glass transition temperature. An elastomeric material having a distinct hysteresis advantageously converts a great deal of mechanical oscillation energy to heat, since for compression, a substantially higher mechanical energy is required than it gives off again during subsequent unloading during the return to its initial shape. The elastomeric material may be a cross-linked elastomeric material. The elastomeric material particularly has a flat spring characteristics line. The damping unit may be configured at least partially from a foam material made of an elastomeric material. A foam material made of an elastomeric material has a particularly distinct hysteresis, and converts a particularly great quantity of oscillation energy to heat. An especially good oscillation damping can be achieved.
The handheld machine tool energy supply unit may have at least one contact unit that is rigidly situated on the accumulator unit. Contact unit should be understood to mean a unit provided to connect the accumulator unit to the handheld machine tool at least electrically. The handheld machine tool has a contact holder which is mechanically and electrically suitable for contacting the contact unit of the accumulator unit, by the contacts of the contacting unit and the contacts of the contact holder touching each other. By “rigidly situated” it should be understood that the contact unit is connected to the accumulator unit essentially nondetachably, and/or is a component of the accumulator unit. The connection need have no damping and/or spring elements. The damping of the contact unit is particularly less than 50%, which may be less than 10% than the damping by the damping unit that is provided for the oscillation damping of the accumulator unit of the handheld machine tool energy supply unit. A particularly safe connection may be achieved of the contact unit to the accumulator unit. In particular, the electrical connections of the accumulator unit between the battery cells or the accumulator cells and the contact unit are loaded only a little. In one additional embodiment of the present invention, a damping unit may be provided which connects the contact unit to the accumulator unit in a damped manner. The contact unit can be situated rigidly on the interface element, which is connected in a damped manner to the accumulator unit via a damping unit. If a damping unit is provided between the contact unit and the accumulator unit, the contact unit may be connected to the accumulator unit using flexible conductors. The accumulator unit may be protected from vibrations and oscillations of the interface element and the contact unit, using a damping element.
It is provided that the handheld machine tool energy supply unit have at least one locking element situated on the interface element, which is provided to connect the interface element rigidly to an handheld machine tool. By “locking element” one should understand particularly an element that is provided to be brought into contact to be locked to another locking element, so that a locking force is able to be transmitted via the two locking elements. For this purpose, the handheld machine tool has a locking element to which the locking element of the handheld machine tool energy supply unit is connected. By “connect rigidly” it should be understood that, in the locked state, the connection between the interface element and the handheld machine tool may have no damping element and/or spring element. The damping of the connection between the interface element and the handheld machine tool is particularly less than 50%, which may be less than 10% of the damping of the damping unit that is provided for the oscillation damping of the accumulator unit of the handheld machine tool energy supply unit. A particularly secure connection may be ensured between the interface element and the handheld machine tool. The interface element may be a part of a protective housing of the handheld machine tool energy supply unit. The oscillation-damped supported accumulator unit may be protected particularly effectively on the inside of an appropriate protective housing.
Furthermore, an handheld machine tool is provided having an interface for connecting to an handheld machine tool energy supply unit, the interface including at least one damping unit. By “damping unit” we mean a unit, situated on the interface of the handheld machine tool, which is provided so as clearly to reduce the transmission of an oscillation or vibration from the handheld machine tool to the handheld machine tool energy supply unit or to parts of the handheld machine tool energy supply unit. The damping unit may be formed from an elastomeric material. The transmission of vibration or oscillation to the handheld machine tool energy supply unit is able to be reduced effectively.
The interface of the handheld machine tool may have a contact holder which has the damping unit, and the former is provided for the oscillation-damped contacting of a contact unit of the handheld machine tool energy supply unit. In an especially particular manner, the damping unit may be situated between an handheld machine tool housing and a contact of the contact holder and/or the damping unit supports the contact holder on the handheld machine tool housing. The damping unit may be elastic, and, in the operating state, it exerts a force in the direction of the contact unit of the accumulator unit. A particularly secure contact is able to be ensured thereby. The damping unit may be made at least partially of an elastomeric material, particularly of an entropy-elastic elastomeric material. It particularly may be the case that if the damping unit is configured at least partially from a foam material made of an elastomeric material. The damping unit is able to include elements which increase the reliability of a contact force between the contact holder and the contact unit of the accumulator unit. In particular, the damping unit may include spring elements. One may thus effectively reduce the transmission of a vibration or oscillation particularly to a contact unit that is mounted rigidly on the accumulator unit of the handheld machine tool energy supply unit. A particularly secure contacting is able to be ensured thereby.
It is further provided that the interface of the handheld machine tool has at least one locking element to the damping unit, which is provided to form an oscillation-damped locking of the handheld machine tool energy supply unit. By “oscillation-damped locking” one should understand locking having great damping corresponding to the damping unit of the handheld machine tool energy supply unit provided. An effective oscillation damping may be achieved in handheld machine tool energy supply units which do not have a sufficient oscillation damping themselves.
Furthermore, a system is provided having an handheld machine tool energy supply unit and an handheld machine tool.
Further advantages are derived from the description of the figures that follow. The drawing shows exemplary embodiments of the present invention. The drawings, the description, and the claims include numerous features in combination. One skilled in the art will expediently consider the features also individually, and will combine them into useful further combinations.
The following description and the drawings of additional exemplary embodiments are limited essentially to the differences between the exemplary embodiments; with reference to components designated the same way, particularly with reference to components having the same reference numerals, especially with reference to the drawings and/or the description of the other exemplary embodiments, one is basically also able to refer to the drawings and/or the description of the other exemplary embodiments.????? To distinguish the exemplary embodiments, instead of the letter a for the first exemplary embodiment, letters b, c and d of the additional exemplary embodiments are appended.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2011 002 404.2 | Jan 2011 | DE | national |
