Power tool assembly with connection interface for releasably attaching an accessory

Abstract

The invention relates to a power tool arrangement comprising an electric drive unit (4) for a tool (5), which is accommodated in a housing (3) of a power tool (1) and can be switched on via an operating switch (2), and a connection interface (8) for the detachable attachment of an accessory (6) to the housing (3), wherein the connection interface (8) is equipped with locking means for preventing operation of the power tool (1) without the accessory (6) attached.

Description

[0001] The present invention relates to a power tool arrangement comprising an electric drive unit for a tool accommodated in a housing of a power tool and switchable via an operating switch, as well as a connection interface for detachably attaching an accessory to the housing of the power tool.

[0002] The field of application of the invention extends primarily to metal-cutting power tools, such as drills, hammer drills, and the like. A variety of accessories are typically offered for such power tools, which can usually be mechanically and / or electrically connected to the power tool via an open connection interface. Such accessories can include, for example, vacuum cleaner units, air blower units, measuring devices, and the like. Whether or not an accessory is used depends on the user of the power tool.

[0003] However, there are applications where the use of an accessory is mandatory, for example, for occupational health and safety reasons. This is the only way to comply with applicable regulations regarding dust emissions on construction sites. The resulting mandatory use of, for example, a vacuum cleaner unit is often subject to the burden of proof on the part of the user, particularly a responsible construction company or building owner. The present invention is dedicated to a technical solution for fulfilling or at least facilitating such a burden of proof. State of the art

[0004] DE 2010 063 515 A1 discloses a generic accessory for a power tool, here in the form of a vacuum unit for a handheld drilling tool. The accessory has a suction head that can accommodate a tool rotatable about a tool axis. Furthermore, a blower is provided, with a fan wheel rotatable about a fan axis for sucking air from the suction head. The fan wheel is connected to the housing via an intake duct, which runs in a first section along the longitudinal axis of the suction module and in a second section along a vertical axis of the suction module that is transverse to the longitudinal axis. The suction module can be releasably attached below the power tool via a connection interface formed correspondingly on the respective housings.

[0005] Given the state of the art described above, it would be possible to operate the power tool without the accessory attached, which would result in significant pollution emissions. To prevent this, warnings have been used or statutory supervisory obligations have been imposed.

[0006] It is the object of the present invention to further improve a power tool arrangement of the generic type in such a way that unauthorized operation without an accessory is objectively prevented. Disclosure of the invention

[0007] This object is achieved by a power tool assembly according to the preamble of claim 1 in conjunction with its characterizing features. The following dependent claims reflect advantageous developments of the invention.

[0008] The invention includes the technical teaching that the connection interface is equipped with locking means for preventing operation of the power tool without an attached accessory.

[0009] The locking means designed according to the invention can be implemented as a mechanical or electronic solution. Within the framework of a mechanical solution, the locking means can be integrated into the power tool and the accessory or arranged externally, as will be described in more detail below.

[0010] In other words, the solution according to the invention thus makes it possible to enforce the use of an accessory on power tools. This limits a conventional open system, to which accessories can be freely added or removed at any time, to a closed system from which accessories cannot be removed, at least temporarily, to ensure operational readiness.

[0011] According to an electronic solution, the locking means between the power tool and the accessory can be equipped with mechanical or electrical detection means for recognizing the connection status of the accessory as "connected" or "not connected", whereby associated operation interruption means for forced control only allow the drive unit to be switched on via the power tool's operating switch if the accessory has been recognized as "connected" by evaluating the connection status.

[0012] The advantage of the electronic solution is that the power tool assembly automatically registers whether a mandatory accessory is connected and can only be operated if it is properly connected to the power tool. If the accessory is not connected to the power tool, the tool will not start or will stop operating as soon as the accessory is disconnected. Implementing this technical solution requires relatively little effort in a conventional power tool assembly and can also be retrofitted.

[0013] The alternative mechanical solution can be implemented internally or externally. On the one hand, within the scope of an internal arrangement, it is possible to configure the locking means with a locking device integrated into the housing with release locking means. An integrated locking device can, for example, be designed in the manner of a built-in lock operable with a key or screwdriver, which is preferably implemented on the part of the accessory and interacts positively with a housing molding or the like on the part of the power tool's housing.

[0014] In addition, it is also conceivable for the locking means to be configured as an external locking device, for example, in the manner of a padlock with a key as the release locking means. In addition to the release locking means being configured as a key, a seal, for example, could also be considered, which at least creates a barrier to unauthorized removal of the accessory. Breaking a seal can result in liability for unauthorized use being transferred to the responsible user. It is also conceivable for release locking means to be configured electrically or electronically, for example in the form of an electromagnet or the like.

[0015] In the case of an integrated or external mechanical locking device, only authorized personnel, a responsible construction company, or a responsible builder or owner are authorized to open the locking device in order to disconnect a coupled accessory from the power tool using a matching key.

[0016] The alternative electronic operation interruption means for forced control of the operation of the power tool can also be designed in different ways. On the one hand, it is conceivable to design the operation interruption means in the manner of an electrical switch or as a mechanical actuation lock for the operating switch. In the former case, for example, a pushbutton switch electrically connected in series with the operating switch can be provided, which closes when a coupling of the accessory to the power tool is detected in the retracted button position. A conventional microswitch can be used for this purpose, for example. Within the framework of a mechanical actuation lock, it is possible, for example, to block the pressing of the operating switch of the power tool using a locking mechanism if a corresponding plunger on the interface side does not detect a coupled accessory.

[0017] In addition to a mechanical component as a detection means for the electrical or mechanical interruption means, electrical detection means, such as an electrically inductive proximity sensor for detecting an accessory mounted at the connection point, can also be used. The inductive proximity sensor can, for example, be installed on the power tool side in the area of ​​the connection interface and interact with a metal element arranged in or on the housing of the accessory.

[0018] It may be provided that the connection interface comprises a mechanical sliding interface or a clip connection between the housing of the power tool and a housing of the accessory.

[0019] According to a further measure improving the invention, it is proposed to use electrical interruption devices, which can also be remotely controlled, in order to deactivate the override from a higher authority. This makes it possible, for example, to have a malfunction rectified by authorized specialist personnel. Detailed description based on drawing

[0020] Further measures improving the invention are described in more detail below, together with the description of preferred embodiments of the invention, with reference to the figures. It shows: Fig. 1 a schematic block diagram of an electric hand tool arrangement with attached accessory and electronic locking means, Fig.2 a perspective view of a power hand tool assembly with attached accessory and integrated mechanical locking means, and Fig. 3a perspective view of a power hand tool assembly with attached accessory and external mechanical locking means.

[0021] According to Fig. 1 A power tool 1, here designed as a hammer drill, comprises a drive unit 4 for a tool 5, which is designed here as a drill and can be switched on via an operating switch 2. An accessory 6, designed as a vacuum cleaner unit, is coupled via an outer housing 7 to the housing 3 of the power tool 1 by means of a connection interface 8, which is designed here as a sliding interface.

[0022] As an exemplary embodiment of electronic locking means, an electrical switch 9 is placed in the area of ​​the connection interface 8 as a means of interrupting operation. Its mechanical actuating button detects an accessory 6 attached to the power tool 1, whereupon the electrical switch 9 moves into the closed position. Since the electrical switch 9 is connected in series with the operating switch 2 of the power tool 1, this forms the prerequisite for switching on the power tool 1 via the operating switch 2 in order to activate the electric drive unit 4. In this exemplary embodiment, the evaluation of the connection status as "connected" is therefore carried out via the logic of the series connection of two electrical switches.

[0023] If, however, the accessory part 6 is removed from the power tool 1, the electrical switch 9 opens, which prevents the power tool 9 from being switched on via the operating switch 2 within the scope of the positive control according to the invention.

[0024] After Fig. 2As an exemplary embodiment of integrated mechanical locking means, the electric hand tool 1 with coupled accessory 6 is equipped at the connection interface 8 with a locking device 10 integrated into the housing. A mechanical key is used here as the release locking means, which is only accessible to authorized persons. In the shown closed state of the integrated locking device 10 - similar to the exemplary embodiment described above - integrated operation interruption means are closed via their detection means, which, within the scope of the positive control, only allows operation of the electric tool 1 with accessory 6. In this exemplary embodiment, the accessory 6 is also a vacuum cleaner unit, which removes dust and particles generated by the tool 5 into a collection container 13 via an intake channel 11 and distal suction head 12.

[0025] The Fig. 3shows an embodiment as an example for external mechanical locking means. In contrast to the previously described embodiment, an external locking device 14 in the manner of a padlock is provided, which interacts with eyelet-like recesses formed on both sides of the housing (not shown in detail here). Here, too, the release locking means are designed as keys.

[0026] The invention is not limited to the preferred embodiments described above. Rather, modifications or alternatives are also conceivable, which are also encompassed by the scope of the following claims. For example, it is also possible to provide a seal instead of or in addition to an external locking device. While this does not prevent unauthorized removal of the accessory, it can at least inhibit it and is helpful for assigning responsibilities. It should also be noted that, within the framework of an electronic solution, service interruption devices can also be remotely controlled, for example, via near-field radio (NFC) or the like. List of reference symbols

[0027] 1Power tool 2Operating switch 3Housing 4Drive unit 5Tool 6Accessory 7Housing 8Connection interface 9Switch 10Integrated locking device 11Suction duct 12Suction head 13Collection container 14External locking device

Claims

1. Power tool arrangement with an electric drive unit (4) for a tool (5) accommodated in a housing (3) of a power tool (1) and switchable via an operating switch (2), and with a connection interface (8) for the detachable attachment of at least one accessory part (6) to the housing (3), characterized in that the connection interface (8) is equipped with locking means to prevent operation of the power tool (1) without the attached accessory (6).

2. Power tool arrangement according to claim 1, characterized in that the blocking means comprise mechanical or electrical detection means for recognizing the connection status of the accessory (6) as "connected" or "not connected", wherein associated operation interruption means for forced control only allow the drive unit (4) to be switched on via the operating switch (2) if the accessory (6) has been recognized as "connected" by evaluating the connection status.

3. Power tool arrangement according to claim 1 or 2, characterized in that the locking means are designed as a mechanical locking device (10) integrated into the housing with release locking means.

4. Power tool arrangement according to one of the preceding claims, characterized in that the locking means are designed as an external locking device (14) with release locking means.

5. Power tool arrangement according to claim 3 or 4, characterized in that the release locking means are designed as a key or seal.

6. Power tool arrangement according to one of the preceding claims, characterized in that the connection interface (8) comprises a mechanical sliding interface between the housing (3) of the power tool (1) and a housing (7) of the accessory (6).

7. Power tool arrangement according to one of claims 2 to 6, characterized in thatthe means for interrupting operation are designed in the manner of an electrical switch (9) or a mechanical actuation lock for the operating switch (2).

8. Power tool arrangement according to claim 7, characterized in that the electrical switch (9) can be operated remotely to deactivate the forced control by a higher authority.

9. Power tool arrangement according to one of claims 2 to 8, characterized in that the detection means comprise a mechanical actuation button of the electrical switch (9) for detecting an accessory (6) mounted on the connection interface (8).

10. Power tool arrangement according to one of claims 2 to 8, characterized in that the detection means comprise an electrically inductive proximity sensor for detecting an accessory (7) mounted on the connection interface.

11. Power tool arrangement according to one of the preceding claims, characterized in thatthe power tool (1) is designed as a drilling tool and the accessory (6) is designed as a vacuum cleaner unit.

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