Abstract: A gas spring-powered fastener driver includes a cylinder, a moveable piston positioned within the cylinder, a driver blade attached to the piston and movable therewith between a ready position and a driven position, a lifter to move the driver blade from the driven position to the ready position, and a transmission including an output shaft operatively coupled to the lifter to provide torque to the lifter. The fastener driver also includes an input to provide torque to the transmission and a clutch positioned downstream of the input and operably coupled to the output shaft to limit an amount of torque transferred to the output shaft and the lifter. In response to an application of a reaction torque to the output shaft above a predetermined threshold, torque from the input is diverted from the output shaft via the clutch.

Abstract: A power unit is configured for use as part of a concrete screed and includes a frame and a powered drive. The frame includes a drive housing. The powered drive is operably supported by the drive housing and is configured to rotate a rotatable concrete forming drum. The powered drive includes an electric motor and a battery operably coupled to the electric motor and configured to power the electric motor. The powered drive includes a drive shaft drivingly connectable relative to the drum, with rotation of the drive shaft causing corresponding rotation of the drum.

Abstract: A concrete screed assembly broadly includes a plurality of elongated drum sections. The drum sections are interchangeably interconnectable in an end-to-end relationship to cooperatively form a rotatable concrete screed drum that is selectively variable depending on the drum sections interconnected to form the drum. The drum sections each present a concrete-forming outer surface configured to engage concrete as the drum is rotated. The drum sections each include opposite connection ends.

Abstract: A concrete screed assembly broadly includes a plurality of elongated drum sections. The drum sections are interchangeably interconnectable in an end-to-end relationship to cooperatively form a rotatable concrete screed drum that is selectively variable depending on the drum sections interconnected to form the drum. The drum sections each present a concrete-forming outer surface configured to engage concrete as the drum is rotated. The drum sections each include opposite connection ends.

Abstract: A power unit is configured for use as part of a concrete screed and includes a frame and a powered drive. The frame includes a drive housing. The powered drive is operably supported by the drive housing and is configured to rotate a rotatable concrete forming drum. The powered drive includes an electric motor and a battery operably coupled to the electric motor and configured to power the electric motor. The powered drive includes a drive shaft drivingly connectable relative to the drum, with rotation of the drive shaft causing corresponding rotation of the drum.

Abstract: A power unit is configured for use as part of a concrete screed and includes a frame and a powered drive. The frame includes a drive housing. The powered drive is operably supported by the drive housing and is configured to rotate a rotatable concrete forming drum. The powered drive includes an electric motor and a battery operably coupled to the electric motor and configured to power the electric motor. The powered drive includes a drive shaft drivingly connectable relative to the drum, with rotation of the drive shaft causing corresponding rotation of the drum.

Abstract: A concrete screed assembly broadly includes a plurality of elongated drum sections. The drum sections are interchangeably interconnectable in an end-to-end relationship to cooperatively form a rotatable concrete screed drum that is selectively variable depending on the drum sections interconnected to form the drum. The drum sections each present a concrete-forming outer surface configured to engage concrete as the drum is rotated. The drum sections each include opposite connection ends.

Abstract: A power unit is configured for use as part of a concrete screed and includes a frame and a powered drive. The frame includes a drive housing. The powered drive is operably supported by the drive housing and is configured to rotate a rotatable concrete forming drum. The powered drive includes an electric motor and a battery operably coupled to the electric motor and configured to power the electric motor. The powered drive includes a drive shaft drivingly connectable relative to the drum, with rotation of the drive shaft causing corresponding rotation of the drum.

Abstract: A power unit is configured for use as part of a concrete screed and includes a frame, a powered drive, and a drive coupler. The frame includes a drive housing and a handle to be grasped by a user, with the handle being configured to facilitate manual advancement of the concrete screed in the forward direction. The handle and the drive housing are pivotally attached relative to each other so that the handle is swingable relative to the drive housing about a pivot axis that is transverse to the forward direction. The powered drive is operably supported by the drive housing and includes a rotatable drive shaft. The drive coupler is attached to the drive shaft and is removably attachable to the connection shaft of a rotatable concrete forming drum so that rotation of the drive shaft is imparted to the connection shaft.

Abstract: A power unit is configured for use as part of a concrete screed and includes a frame, a powered drive, and a mechanical control connection. The frame includes a drive housing and a handle to be grasped by a user, with the handle being configured to facilitate manual advancement of the concrete screed in a forward direction. The handle includes a grip and a relatively shiftable user-operated drive controller. The powered drive is operably supported by the drive housing and is configured to rotate a rotatable concrete forming drum.

Abstract: A power unit is configured for use as part of a concrete screed and includes a frame and a powered drive. The frame includes a drive housing. The powered drive is operably supported by the drive housing and is configured to rotate a rotatable concrete forming drum. The powered drive includes an electric motor and a battery operably coupled to the electric motor and configured to power the electric motor. The powered drive includes a drive shaft drivingly connectable relative to the drum, with rotation of the drive shaft causing corresponding rotation of the drum.

Abstract: A power unit is configured for use as part of a concrete screed and includes a frame, a powered drive, and a drive coupler. The frame includes a drive housing and a handle to be grasped by a user, with the handle being configured to facilitate manual advancement of the concrete screed in the forward direction. The handle and the drive housing are pivotally attached relative to each other so that the handle is swingable relative to the drive housing about a pivot axis that is transverse to the forward direction. The powered drive is operably supported by the drive housing and includes a rotatable drive shaft. The drive coupler is attached to the drive shaft and is removably attachable to the connection shaft of a rotatable concrete forming drum so that rotation of the drive shaft is imparted to the connection shaft.

Abstract: A power unit is configured for use as part of a concrete screed and includes a frame, a powered drive, and a mechanical control connection. The frame includes a drive housing and a handle to be grasped by a user, with the handle being configured to facilitate manual advancement of the concrete screed in a forward direction. The handle includes a grip and a relatively shiftable user-operated drive controller. The powered drive is operably supported by the drive housing and is configured to rotate a rotatable concrete forming drum.

Abstract: A power unit is configured for use as part of a concrete screed and includes a frame and a powered drive. The frame includes a drive housing. The powered drive is operably supported by the drive housing and is configured to rotate a rotatable concrete forming drum. The powered drive includes an electric motor and a battery operably coupled to the electric motor and configured to power the electric motor. The powered drive includes a drive shaft drivingly connectable relative to the drum, with rotation of the drive shaft causing corresponding rotation of the drum.

Abstract: One data stream is input to a radio frequency (RF) input terminal of a first receiver interface circuit, and the second bit stream is applied to an RF input terminal of a second receiver interface circuit. Each of the receiver interface circuits includes a Reed-Solomon frame synchronization, forward error correction and derandomizer module receiving the bit stream pattern from the RF terminal of the ground station. Following processing in the derandomizer module, the bit stream is input to a wide band frame synchronization module for synchronization on byte-aligned synchronization pattern at the beginning of each wide-band communications block frame. When synchronization has been established, the data frames are collected for transfer to a memory buffer module. Data buffered in the memory buffer module is direct memory access transferred by a VERSA Module Eurocard (VME) bus interface module to the satellite ground station.