Abstract: A drive system includes a carrying device with a wearable carrying frame, an energy store carried by the carrying frame, and at least one electric drive motor carried by the carrying frame. A coupling device is configured to mechanically couple a work apparatus to the drive system. The carrying device is formed as a shoulder bag or backpack, having at least one strap that permits the carrying device to be worn over a shoulder of a user. Two straps may be provided that permit the carrying device to be worn over both shoulders of a user. Also disclosed is a tool having such a drive system and a work apparatus, which may be concrete vibrator.

Abstract: A concrete compaction device includes a vibrator housing for immersion in flowable concrete, and an unbalance exciter which is driven by an electric motor and which is arranged in the vibrator housing. A current detection device detects the electric current absorbed by the electric motor. Ann evaluation device determines an operating state of the concrete compaction device based on the electric current that is currently detected. The operating state is selected from the group consisting of: positioning of the vibrator housing in the air, immersion of the vibrator housing in the concrete, performance of a compaction process with the vibrator housing immersed in the concrete, and emersion of the vibrator housing from the concrete. The evaluation device is configured to recognize all of these operating states.

Abstract: A concrete compaction system includes an unbalance exciter for concrete compaction, a compaction detection device for detecting progress of the compaction in the concrete, and a vibration device for generating a haptic feedback when a prescribed progress of the compaction has been detected by the compaction detection device. An electric motor may drive the unbalance exciter and may be powered by an electric power supply and a converter device for converting an electric current from the electric power supply to a drive current for the electric motor. The compaction detection device may comprise a measurement device for measuring the current drawn from the electric motor. The compaction detection device may also comprise an evaluation device for evaluating the current drawn measured by the measurement device, for determining therefrom the progress of the compaction in the concrete, and for detecting whether a prescribed progress of the compaction has been achieved.

Abstract: A work machine includes a working device for generating a working motion; an electric motor for driving the working device; an electric energy storage device for supplying the electric motor with electric current; and a cooling device for cooling the energy storage device. The cooling device comprises at least one fan device for generating a cooling air flow which can be directed over the energy storage device. At least one temperature sensor is provided for detecting a temperature, and a control device is provided for controlling the fan device as a function of the temperature detected by the temperature sensor.

Abstract: A drive system includes a carrying device with a wearable carrying frame, an energy store carried by the carrying frame, and at least one electric drive motor carried by the carrying frame. A coupling device is configured to mechanically couple a work apparatus to the drive system. The carrying device is formed as a shoulder bag or backpack, having at least one strap that permits the carrying device to be worn over a shoulder of a user. Two straps may be provided that permit the carrying device to be worn over both shoulders of a user. Also disclosed is a tool having such a drive system and a work apparatus, which may be concrete vibrator.

Abstract: A carrying device includes a carrying frame, an energy store carried by the carrying frame, a transformer device, carried by the carrying frame, for transforming an electric current drawn from the energy store, and an electrical connection device, carried by the carrying frame, for connecting the carrying device to a consumer. The carrying device is in the form of a shoulder bag or backpack having at least one strap for wearing the carrying device over one or both shoulders of a user.

Abstract: A drive system includes a carrying device with a wearable carrying frame, an energy store carried by the carrying frame, and at least one electric drive motor carried by the carrying frame. A coupling device is configured to mechanically couple a work apparatus to the drive system. The carrying device is formed as a shoulder bag or backpack, having at least one strap that permits the carrying device to be worn over a shoulder of a user. Two straps may provided that permit the carrying device to be worn over both shoulders of a user.

Abstract: The invention relates to an air-cooled frequency converter, especially for construction site equipment, such as internal and external vibrators which are operated at a higher frequency than the existing electricity supply, said frequency converter comprising a housing and preferably being connected to a separation transformer for producing a protective extra-low voltage. The housing is divided into a converter receiving element surrounding a plate chamber, and a housing section connected to the receiving element and used as a cooling region, inside which cooling air channels and a fan for conveying the cooling air through the cooling air channels are arranged. The configuration of the housing in the cooling region are created by annular profiled elements which are cross-cut as desired, surround each other in an interspaced manner, and are coaxially arranged in relation to each other.

Abstract: The invention relates to an air-cooled frequency converter, especially for construction site equipment, such as internal and external vibrators which are operated at a higher frequency than the existing electricity supply, said frequency converter comprising a housing and preferably being connected to a separation transformer for producing a protective extra-low voltage. The housing is divided into a converter receiving element surrounding a plate chamber, and a housing section connected to the receiving element and used as a cooling region, inside which cooling air channels and a fan for conveying the cooling air through the cooling air channels are arranged. The configuration of the housing in the cooling region are created by annular profiled elements which are cross-cut as desired, surround each other in an interspaced manner, and are coaxially arranged in relation to each other.

Abstract: The invention relates to an air-cooled frequency converter, especially for construction site equipment, such as internal and external vibrators which are operated at a higher frequency than the existing electricity supply, said frequency converter comprising a housing and preferably being connected to a separation transformer for producing a protective extra-low voltage. Said housing is divided into two sections, that is into a converter receiving element surrounding a plate chamber, and a housing section connected to said receiving element and used as a cooling region, inside which cooling air channels and a fan for conveying the cooling air through the cooling air channels are arranged. The configuration of the housing in the cooling region and optionally the embodiment of a transformer chamber are created by annular profiled elements which are cross-cut as desired, surround each other in an interspaced manner, and are coaxially arranged in relation to each other.

Abstract: An electronic frequency converter is used with a high frequency immersion vibrator in order to compact concrete. The frequency converter comprises a cooling circuit containing a cooling medium; a first heat exchanger which is integrated into said cooling circuit and is used to transmit heat generated in the housing of the frequency converter to the cooling medium; and a second heat exchanger which is integrated into the cooling circuit and is used to outwardly transmit heat absorbed by the cooling medium. The second heat exchanger is received in a vibrator housing of the high frequency immersion vibrator. If the vibrator housing is immersed in concrete, the heat produced in the converter housing can be conducted away to the concrete.

Abstract: The invention relates to an electronic frequency converter (1) which is used with a high frequency immersion vibrator in order to compact concrete. Said frequency converter comprises a cooling circuit (4) containing a cooling medium; a first heat exchanger (3) which is integrated into said cooling circuit (4) and is used to transmit heat generated in the housing (2) of the frequency converter to the cooling medium; and a second heat exchanger (11) which is integrated into the cooling circuit (4) and is used to outwardly transmit heat absorbed by the cooling medium. The second heat exchanger (11) is received in a vibrator housing (6) of the high frequency immersion vibrator. If the vibrator housing (6) is immersed in concrete (12), the heat produced in the converter housing (2) can be conducted away to the concrete (12).

Abstract: The invention relates to a concrete compacting device for compacting plastically deformable concrete in a formwork, comprising at least one vibrating unit which is attached to the formwork and has a vibration-generating unit. The compacting device is characterized in that the vibrating unit comprises an acceleration sensor for generating a signal corresponding to a vibration generated by the vibration-generating unit at the level of the formwork, and a control unit which is impinged upon by said signal and serves to control operating parameters of the vibration-generating unit.