Shock-absorbing unit for a storage battery

Abstract

The invention relates to a machine tool (1), in particular a chipping hammer, comprising a housing (3), a work axis (9) extending in a longitudinal direction, at least one storage-battery interface device (19, 21) for releasably connecting at least one storage battery (15, 17) to the machine tool (1), and a first side handle (5) having a first main extension direction (33), and a second side handle (7) having a second main extension direction (35). The side handles (5, 7) are arranged substantially symmetrically with respect to the work axis (9). At least one decoupling device (39, 41) is provided for connecting the side handles (5, 7) to the housing (3) in a vibration-damping manner. A protective device (75) is provided for protecting a storage battery (15, 17) which is coupled to the storage-battery interface device (19, 21). The protective device (75) has an interior (93) for accommodating at least part of at least one storage battery (15, 17). The protective device (75) circumferentially surrounds the housing (3) with respect to the longitudinal direction (9) and is connected to at least one side handle (5, 7) via at least one connecting device (78)

Description

[0001] Shock absorption device for an accumulator

[0002] The present invention relates to a machine tool, in particular a chisel hammer, according to the type defined in more detail in the preamble of patent claim 1.

[0003] EP 3 943 251 A1 discloses a chisel hammer with a housing, wherein a drive device of the chisel hammer can be supplied with energy from accumulators. Two laterally arranged handles are provided, with a decoupling device being provided to reduce vibrations acting on the handles during operation. The chisel hammer is designed for the arrangement of two accumulators, each of which can be arranged on a side of the housing facing away from a tool holder and thus above the housing by means of a battery interface device. A protective device is provided to protect the accumulators.

[0004] The disadvantage of such a chipping hammer is its high height along its length. If the chipping hammer tips over or falls, the accumulators can be subjected to significant forces due to the potentially great fall height, so the protective device must be particularly sturdy and robust.

[0005] Furthermore, DE 10 2018 210 189 A1 discloses a percussion hammer with a housing, wherein a center of gravity of the power tool is arranged substantially on the working axis. The power tool has a battery interface via which a battery pack can be detachably connected to the power tool. The handles are each connected to the housing via a damping unit. It is further disclosed that the battery pack is arranged below a handle and protected by a protective element connected to the handle.

[0006] Disadvantageously, protection of the battery pack in such a design may be inadequate or undesirably low, particularly in the event of a fall of the machine tool or impact.

[0007] The object of the present invention is to provide a machine tool, in particular a chipping hammer, in which the installation height of the machine tool is reduced and reliable protection of batteries connected to the machine tool is achieved in a structurally simple manner. This object is achieved by the subject matter of independent claim 1. Further advantageous embodiments of the invention can be found in the corresponding subclaims.

[0008] A machine tool, in particular a chisel hammer, is proposed, comprising a housing, a working axis extending in a longitudinal direction, at least one battery interface device for a releasable connection of at least one battery to the machine tool and a first side handle with a first main extension direction and a second side handle with a second main extension direction, wherein the side handles are arranged substantially symmetrically to the longitudinal direction, wherein at least one decoupling device is provided for the vibration-damping connection of the side handles to the housing, wherein a protective device is provided for protecting a battery coupled to the battery interface device, and wherein the protective device has an internal volume for at least partially accommodating the at least one battery.

[0009] According to the invention, it is proposed that the protective device encompasses the housing in the circumferential direction with respect to the longitudinal direction and is connected to at least one side handle via at least one connecting device.

[0010] A machine tool designed according to the invention has the advantage that batteries connected to the at least one battery interface device can be easily protected from damage to the desired extent, particularly in all operating states of the machine tool. This is achieved by the design of the protective device encompassing the housing, thereby easily supporting the protective device on the housing. Furthermore, batteries connected to the battery interface device are protected from vibrations during operation by the coupling of the battery interface device to the side handles, which are decoupled from the housing by means of the decoupling device.

[0011] Furthermore, a machine tool designed according to the invention has an advantageously low installation height in the longitudinal direction of the machine tool. This is achieved in that the protective device encompasses the housing and is therefore not arranged on a side of the housing facing away from a tool holder. Furthermore, compared to an arrangement of the battery interface device in an end region of the machine tool facing away from a tool holder, a center of gravity of the proposed machine tool is advantageously arranged close to a machining surface. As a result, the maximum fall height of a battery connected to the battery interface device during operation of the machine tool is also reduced compared to an arrangement of the battery in an end region of the machine tool facing away from the tool holder, so that the risk of damage to a battery connected to the battery interface device is reduced.

[0012] The first side handle and the second side handle each define a first main direction of extension and a second main direction of extension, respectively. In an unloaded state of the side handles, the main directions of extension are arranged, in particular, substantially perpendicular to the longitudinal direction and extend substantially in a transverse direction. A center of gravity of the machine tool in an upright position preferably lies substantially on a working axis of the machine tool defined by the tool holder.

[0013] The decoupling device reduces the mechanical impacts, such as shocks, impacts, or similar, that affect a user holding the power tool by the side handles during operation. Furthermore, the decoupling device also protects a battery connected to the battery interface device from mechanical impacts, and its impact on a battery connected to the battery interface device is significantly reduced.

[0014] In an advantageous embodiment of a machine tool according to the invention, the connecting device enables movement of the protective device essentially in the longitudinal direction relative to the housing. This easily decouples the protective device, and thus also the battery interface device, from the housing. Furthermore, the housing can act as a guide for the protective device and contribute to its stability.

[0015] In a structurally simple embodiment of the invention, the connecting device comprises at least two levers, wherein the protective device is connected to the first side handle by a first lever and to the second side handle by a second lever. The protective device is coupled to the side handles via the levers and, similar to the side handles, is protected by the decoupling device from vibrations acting on the housing during operation of the machine tool.

[0016] Particularly good protection of batteries connected to the battery interface device can be achieved if the connecting device has at least two flexible elements, with the protective device being connected to the first side handle by a first flexible element and to the second side handle by a second flexible element. The flexible elements can further dampen vibrations acting on the protective device and thus also on batteries during operation of the machine tool. Furthermore, additional protection is also ensured in the event of a fall or a crash of the machine tool.

[0017] In a preferred embodiment of a machine tool according to the invention, the flexible elements are made of an elastomeric material. However, in principle, any material with spring or damping properties can be used.

[0018] In order to limit the range of movement of the protective device relative to the housing in the longitudinal direction and thereby achieve good fall protection, the protective device can have a first stop area and the housing can have a second stop area, wherein the protective device and the housing come into contact with one another via the stop areas when the protective device is displaced relative to the housing by a defined limit value in the longitudinal direction starting from a rest position.

[0019] Alternatively or additionally, the protective device may have a third stop region and the housing may have a fourth stop region, wherein the third stop region and the fourth stop region extend substantially in the longitudinal direction. The interaction of the third stop region with the fourth stop region, which are preferably designed to be circumferential, provides guidance of the protective device relative to the housing for vibration damping. This interaction also provides support for the protective device on the housing, for example, in the event of a fall or overturn of the machine tool.When the machine tool is at rest, there is a distance between the third stop area and the fourth stop area, particularly on the circumferential side, which is selected in such a way that jamming of the protective device relative to the housing during operation of the machine tool is reliably prevented.

[0020] An improved embodiment of the invention with regard to a center of gravity, a user's view in the direction of a work area, and a structural length of the machine tool is achieved if the protective device and thus also the battery interface device and a battery optionally connected to the battery interface device are arranged with respect to the longitudinal direction on a side of the respective side handle facing a tool holder and in particular in the longitudinal direction below the side handles. In an advantageous embodiment of a machine tool according to the invention, the protective device has at least two battery interface devices, wherein the battery interface devices are arranged in particular substantially symmetrically to the longitudinal axis. It can also be provided that the protective device has three, four or more battery interface devices.At least one rechargeable battery can be connected to a battery interface device. It can also be provided that two, three, or more rechargeable batteries can be operatively connected to a battery interface device.

[0021] To enable a battery to be arranged in a simple insertion direction on the respective battery interface device, at least one protective device can have a recess oriented substantially perpendicular to the longitudinal direction and perpendicular to a transverse direction for operatively connecting a battery to the battery interface device. In principle, the protective device can also be designed in such a way that a battery can be arranged on the respective battery interface device in any insertion direction.

[0022] In an advantageous embodiment of a machine tool according to the invention, at least one protective device is configured such that, when the battery is connected to the battery interface device and the machine tool falls in any direction, the at least one protective device comes into contact with a flat surface in front of the battery connected to the battery interface device. This ensures particularly good protection of a battery connected to a battery interface device in any operating situation.

[0023] In an advantageous embodiment of the invention, in order to decouple the side handles from the housing, a first decoupling device is provided, which has a first spring device and a first lever device, by means of which the first side handle is rotatably connected to a first pivot point fixed to the housing, and a second decoupling device is provided, which has a second spring device and a second lever device, by means of which the second side handle is rotatably connected to a second pivot point fixed to the housing, wherein the first spring device is mounted on the one hand so that it is fixed to the housing and on the other hand is connected to the first lever device, and wherein the second spring device is mounted on the one hand so that it is fixed to the housing and on the other hand is connected to the second lever device. The spring devices are designed in particular as tension springs and reduce vibrations acting on the side handles during operation of the machine tool.Further advantages will become apparent from the following description of the figures. Various embodiments of the present invention are illustrated in the figures. The figures, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0024] They show:

[0025] Fig. 1 is a side view of a machine tool designed as a chisel hammer with a chisel arranged in a tool holder, the machine tool being shown in an unloaded rest state;

[0026] Fig. 2 is a three-dimensional view of the chisel hammer according to Fig. 1;

[0027] Fig. 3 is a side view of the chisel hammer according to Fig. 1 and Fig. 2, corresponding to Fig. 1, wherein the chisel hammer is shown without a housing part;

[0028] Fig. 4 is a side view of the chisel hammer according to Fig. 1 to Fig. 3, rotated by 90° compared to the illustration in Fig. 1; and

[0029] Fig. 5 is a side view of the chisel hammer according to Fig. 1 to Fig. 4 arranged on a flat surface, wherein a protective device is visible in a sectional view.

[0030] Examples of implementation:

[0031] In Fig. 1 to Fig. 5, a machine tool 1 is shown in the form of a chisel hammer. However, it is also possible for the machine tool 1 to be designed in the form of a screwdriver, a drill, a hammer drill, or the like.

[0032] The machine tool 1 designed as a chisel hammer is shown in the figures in a rest position, i.e. a non-actuated state, and has a housing 3 which can be made of one or more parts. The machine tool 1 also has a first side handle 5 and a second side handle 7 which are arranged essentially symmetrically to a working axis 9 which defines a longitudinal axis or longitudinal direction of the machine tool 1. In the present case, a tool holder 11 is in engagement with a tool 13 designed as a chisel, which lies in the working axis 9. Contained inside the housing 3 are an electric motor and an impact device. The impact device can also be referred to as a percussion mechanism or impact mechanism device. The electric motor and the impact device are connected to one another in such a way that pulse-like impacts are generated and transmitted to the tool holder 11.Neither the electric motor nor the impact device are shown in the figures.

[0033] To supply the machine tool 1, and in particular the electric motor, with electrical energy, a first accumulator 15 and a second accumulator 17 are provided, wherein the first accumulator 15 is operatively connected to a first battery interface device 19 and the second accumulator 17 is operatively connected to a second battery interface device 21. The battery interface devices 19, 21 are arranged on a protective device 75, which will be discussed in more detail later.

[0034] According to an alternative embodiment, it is also possible that only one accumulator or more than two accumulators are used.

[0035] The housing 3 has a lower end 23 in the longitudinal direction 9, in the region of which the tool holder 11 is provided, and an opposite upper end 25. Furthermore, the housing 3 has a first side region 27 and a second side region 29. The side regions 27, 29 form opposite boundaries of the housing 3 in the transverse direction 31. The transverse direction 31 is perpendicular to the working axis 9 and, in this case, is essentially identical to the main extension directions 33, 35 of the side handles 5, 7 in the idle state of the machine tool 1.

[0036] The first side handle 5 is arranged in the first side region 27 and the second side handle 7 is arranged in the second side region 29 of the housing 3, which is opposite the first side region 27 in the transverse direction 31.

[0037] A decoupling device 37 is provided, which can be seen in more detail in Fig. 3, by means of which the side handles 5 and 7 are decoupled to a certain extent from the housing 3 and thus from shocks, vibrations and the like transmitted to the housing 3 via the chisel 13 during operation of the machine tool 1.

[0038] The decoupling device 37 in the present case has a first decoupling device 39 assigned to the first side handle 5 and a second decoupling device 41 assigned to the second side handle 7. The first decoupling device 39 has a first spring device designed as a tension spring 43 and a first lever device 45, wherein the first lever device 45 is articulated on the one hand to a first pivot point 47 fixed to the housing and on the other hand is connected to the first side handle 5. The first tension spring 43 is mounted on the one hand so that it is fixed to the housing and on the other hand is connected to a first articulation point 49 which lies between the first pivot point 47 fixed to the housing and the first side handle 5.The first side handle 5 can thus be displaced relative to the housing 3 in a circular segment-shaped movement about the first pivot point 47 fixed to the housing, so that the first main extension direction 33 can be rotated relative to the transverse direction 31 by a certain angular range.

[0039] Comparably, the second decoupling device 41 has a second spring device designed as a tension spring 51 and a second lever device 53, wherein the second lever device 53 is articulated on the one hand to a second pivot point 55 fixed to the housing and on the other hand is connected to the second side handle 7. The second tension spring 51 is mounted on the one hand so that it is fixed to the housing and on the other hand is connected to a second articulation point 57 which lies between the first pivot point 47 fixed to the housing and the first side handle 5. The second side handle 7 can thus be displaced relative to the housing 3 in a circular segment-shaped movement about the second pivot point 55 fixed to the housing, so that the second main extension direction 35 can be rotated relative to the transverse direction 31 by a certain angular range.

[0040] It can be provided that each decoupling device 39, 41 is assigned two tension springs 43, 51, so that two tension springs 43 interact with the first lever device 45 and two tension springs 51 interact with the second lever device 53.

[0041] The first housing-fixed pivot point 47 is arranged in the transverse direction 31 between the second housing-fixed pivot point 55 and the second side handle 7. Consequently, the second housing-fixed pivot point 55 is arranged in the transverse direction 31 between the first housing-fixed pivot point 47 and the first side handle 5. The lever devices 45 and 53 are bent in opposite directions such that they enable simultaneous movement of the first side handle 5 and the second side handle 7 downwards and upwards in the direction of the working axis by means of a rotational movement about the respective housing-fixed pivot point 47 or 55.

[0042] In the exemplary embodiment shown, the protective device 75 is arranged on a side of the side handles 5, 7 facing the tool holder 11 and has a housing 77 which surrounds or encloses the housing 3 of the machine tool 1 on the circumference. The protective device 75 is designed essentially symmetrically to a central longitudinal plane of the machine tool 1. In this case, the protective device 75 is connected to the side handles 5, 7 via a connecting device 78. The connecting device 78 comprises a first lever 79, by means of which the protective device 75 is connected to the first side handle 5, and a second lever 81, by means of which the protective device 75 is connected to the second side handle 9. The first lever 79 has a first articulation point 83 in a region of the first side handle 5 close to the housing and a second articulation point 84 in an outer region of the protective device 75 in the transverse direction 31.Similarly, the second lever 81 has a third pivot point 85 in a region of the second side handle 7 near the housing and a fourth pivot point 86 in an outer region of the protective device 75 in the transverse direction 31. The second pivot point 84 and the fourth pivot point 86 are thus arranged in regions of the protective device 75 that are far apart from each other in the transverse direction 31.

[0043] The protective device 75 is movable relative to the housing 3 of the machine tool 1 via the linkage by means of the levers 79 and 81 to the side handles 5, 7 during operation of the machine tool 1 with the side handles 5, 7, wherein the protective device 75 is displaceable relative to the housing 3 of the machine tool 1 to a defined extent in the longitudinal direction 9 via the interaction of the decoupling device 37 with the levers 79, 81 during operation of the machine tool 1.

[0044] In the rest position of the machine tool 1 shown in the figures, there is a small distance between the housing 77 of the protective device 75 and the housing 3 of the machine tool 1 transversely to the working axis 9 in order to prevent the protective device 75 from jamming relative to the housing 3 during operation of the machine tool 1.

[0045] In order to ensure good protection for the batteries 15, 17 connected to the battery interface devices 19, 21 during operation of the machine tool 1 and in particular also in the event of a fall, a crash or the like of the machine tool 1, the housing 77 of the protective device 75 has a first stop region 87 and the housing 3 has a second stop region 88 provided for interaction with the first stop region 87. The first stop region 87 and the second stop region 88 are at a defined distance from one another in the longitudinal direction 9 when the machine tool 1 is in the rest position. If the protective device 75 is activated during operation of the machine tool 1 orIn particular, in the event of a fall, a crash or the like of the machine tool 1 in a direction facing away from the tool holder 11 with respect to the longitudinal direction 9, the housing 77 of the protective device 75 comes into contact with the second stop region 88 of the housing 3 after overcoming the distance via the first stop region 87. This provides additional support for the protective device 75 on the housing 3 and thereby also improved protection for batteries 15, 17 connected to the battery interface devices 19, 21.

[0046] In addition, the protective device 75 in this case has a third, preferably completely circumferential stop region 89. The housing 3 has a fourth stop region 90, which is intended to interact with the third stop region 89 of the protective device 75. For example, if the machine tool 1 falls or crashes, part of the third circumferential stop region 89 of the protective device 75 comes into contact with part of the fourth stop region 90 of the housing 3. The protective device 75 preferably bears against the housing 3 over a continuous region in the longitudinal direction 9, so that a good supporting effect is achieved and batteries 15, 17 connected to the battery interface devices 19, 21 are particularly well protected.

[0047] The first battery interface device 19 is arranged here in a region of the protective device 75 assigned to the first side handle 5, i.e., on the same side of the machine tool 1 as the first side handle 5 with respect to the transverse direction 31. Similarly, the second battery interface device 21 is arranged in a region of the protective device 75 assigned to the second side handle 7, i.e., on the same side of the machine tool 1 as the second side handle 7 with respect to the transverse direction 31, and on a side of the machine tool 1 opposite the side of the first side handle 5.

[0048] The first battery interface device 19 is designed to be substantially mirror-symmetrical with respect to the working axis 9 to the second battery interface device 21, wherein the first battery interface device 19 is described below as representative of the second battery interface device 21.

[0049] The first battery interface device 19 has a substantially flat base plate 61 and a connection device 63 for receiving the first battery 15, wherein the first battery 15 is operatively connected to the connection device 63 via a movement in the insertion direction 65 and can be detached from the connection device 63 in an oppositely oriented direction of movement. With the aid of the connection device 63, the second battery 17 can be detachably connected to the protective device 75 and thus connected both mechanically and electrically to the machine tool 1. Due to the detachable connection of the first battery 15, electrical energy can be supplied from the batteries 15, 17 to the consumers, e.g., the electric motor, of the machine tool 1. It is possible for only a single battery to be used to supply the machine tool 1.In the present case, the insertion direction 65 is oriented perpendicular to the longitudinal direction 9 and to the transverse direction 31 in a front direction 95. In alternative embodiments, it can in principle be oriented in any desired direction and, for example, extend in the transverse direction 31. Furthermore, the insertion direction 65 can be at an angle to the front direction 95, the transverse direction 31, and / or the longitudinal direction 9.

[0050] To accommodate the first accumulator 15, the protective device 75 has a recess 91, which enables the first accumulator 15 to be arranged in the insertion direction 65 on the first battery interface device 19. In alternative embodiments, the recess can also be provided at other positions, so that the accumulator can be arranged on the first battery interface device with insertion directions 65 that are essentially oriented in almost any direction.

[0051] In an assembled state of the first protective device 75, the protective device 75 forms a type of cage with an interior space 93. The protective device 75 is designed in this case such that the accumulator 17 can be arranged completely in the interior space 93 defined by the protective device 75.

[0052] The protective device 75 can generally be designed as a single or multi-part unit. It can be provided that the accumulator, when connected to the battery interface device, is not completely located within the interior space, but rather protrudes at least partially from the interior space.

[0053] In this case, however, the protective device 75 is preferably also designed such that if the machine tool 1 falls or falls in any direction, the protective device 75 comes into contact with a flat surface 97 in front of a battery 15 connected to the battery interface device 19, so that the battery 15 is protected to the desired extent by the protective device 75.

Claims

Patent claims: Machine tool (1), in particular a chisel hammer, with a housing (3), a Longitudinal direction (9) extending working axis, at least one battery interface device (19, 21) for a releasable connection of at least one battery (15, 17) to the machine tool (1) and a first side handle (5) with a first main extension direction (33) and a second side handle (7) with a second main extension direction (35), wherein the side handles (5, 7) are arranged substantially symmetrically to the longitudinal direction (9), wherein at least one decoupling device (39, 41) is provided for the vibration-damping connection of the side handles (5, 7) to the housing (3), wherein a protective device (75) is provided for protecting a battery (15, 17) coupled to the battery interface device (19, 21), and wherein the protective device (75) has an interior space (93) for at least partially accommodating at least one battery (15, 17), characterized in thatthat the protective device (75) surrounds the housing (3) of the machine tool (1) in the circumferential direction with respect to the longitudinal direction (9) and is connected to at least one side handle (5, 7) via at least one connecting device (78). Machine tool according to claim 1, characterized in that the connecting device (78) is designed such that the protective device (75) is movable substantially in the longitudinal direction (9) relative to the housing (3). Machine tool according to one of the preceding claims, characterized in that the connecting device (78) has at least two levers (79, 81), wherein the protective device (75) is connected to the first side handle (5) by means of a first lever (79) and to the second side handle (7) by means of a second lever (81). Machine tool according to one of the preceding claims, characterized in that the connecting device (78) has at least two flexible elements,wherein the protective device is connected to the first side handle (5) by means of a first flexible element and to the second side handle (7) by means of a second flexible element. Machine tool according to claim 4, characterized in that the flexible elements are made of an elastomeric material. Machine tool according to one of the preceding claims, characterized in that the protective device (75) has a first stop region (87) and the housing (3) of the machine tool (1) has a second stop region (88), wherein the protective device (75) and the housing (3) of the machine tool (1) come into contact with one another via the stop regions (87, 88) when the protective device (75) is displaced relative to the housing (3) of the machine tool (1) in the longitudinal direction (9) by a value greater than a defined limit value, starting from a rest position.Machine tool according to one of the preceding claims, characterized in that the protective device (75) has a third stop region (89) and the housing (3) of the machine tool (1) has a fourth stop region (90), wherein the third stop region (89) and the fourth stop region (90) extend substantially in the longitudinal direction (9). Machine tool according to one of the preceding claims, characterized in that the protective device (75) is arranged, with respect to the longitudinal direction (9), on a side of the respective side handle (5, 7) facing a tool holder (11). Machine tool according to one of the preceding claims, characterized in that the protective device (75) has at least two battery interface devices (19, 21), wherein the battery interface devices (19, 21) are arranged, in particular, substantially symmetrically to the longitudinal axis (9).Machine tool according to one of the preceding claims, characterized in that the protective device (75) has at least one recess (91) pointing substantially perpendicular to the longitudinal direction (9) and perpendicular to a transverse direction (31) for the operative connection of a rechargeable battery (15, 17) to the rechargeable battery interface device (19, 21). Machine tool according to one of the preceding claims, characterized in that the protective device (75) is designed such that when the accumulator (15, 17) is connected to at least one battery interface device (19, 21) and the machine tool (1) falls in any direction, the protective device (75) comes into contact with a flat surface (97) in front of the accumulator (15, 17) connected to the battery interface device (19, 21).Machine tool according to one of the preceding claims, characterized in that a first decoupling device (39) is provided, which has a first spring device (43) and a first lever device (45), by means of which the first side handle (5) is rotatably connected to a first pivot point (47) fixed to the housing, and a second decoupling device (41) is provided, which has a second spring device (51) and a second lever device (53), by means of which the second side handle (7) is rotatably connected to a second pivot point (55) fixed to the housing, wherein the first spring device (43) is mounted on the one hand so that it is fixed to the housing and on the other hand is connected to the first lever device (45), and wherein the second spring device (51) is mounted on the one hand so that it is fixed to the housing and on the other hand is connected to the second lever device (53).

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