A lawn trimmer including a cutting disc, a drive shaft; and a flexible drive shaft. The drive shaft is within a straight shaft, connected to the motor and extending to the flexible drive shaft, translating the rotation of the motor to the flexible drive shaft. The flexible drive shaft is within a curved shaft, parallel but not-colinear with the straight shaft, extends to a rotor head connected to the curved shaft, translating drive shaft rotation to a cutting disc comprising a plurality of cutting blades on a cutting plane; an intersection between the cutting plane and the curved shaft axis defines a predetermined oblique angle.

A lawn trimmer including a cutting disc, a drive shaft; and a flexible drive shaft. The drive shaft is within a straight shaft, connected to the motor and extending to the flexible drive shaft, translating the rotation of the motor to the flexible drive shaft. The flexible drive shaft is within a curved shaft, parallel but not-colinear with the straight shaft, extends to a rotor head connected to the curved shaft, translating drive shaft rotation to a cutting disc comprising a plurality of cutting blades on a cutting plane; an intersection between the cutting plane and the curved shaft axis defines a predetermined oblique angle.

A flexible connecting system consists of a flexible connecting rod manufactured from a rigid material, a leading segment and a trailing segment. The body has at least one flexible center section, each having at least one slot to provide flexibility. The slot follows a sinuous, serpentine path to form a plurality of interlocking teeth that can follow a helical or a concentric path. One or more flexible sleeves are dimensioned to fit over the connecting rod to prevent the ingress or egress of material. One or both of the ends of the flexible connecting rod and flexible sleeve can be open or sealed.

A driveshaft misalignment measurement system for a drivetrain of an aircraft includes a driveshaft having a first end forming a driveshaft spline and a drivetrain subsystem including a spline adapted to connect to the driveshaft spline to form a splined connection. Rotational energy is transferred between the drivetrain subsystem and the driveshaft via the splined connection. The driveshaft misalignment measurement system also includes accelerometers coupled to the drivetrain configured to detect acceleration data and a flight control computer configured to measure misalignment at the splined connection using the acceleration data.

A driveshaft misalignment measurement system for a drivetrain of an aircraft includes a driveshaft having a first end forming a driveshaft spline and a drivetrain subsystem including a spline adapted to connect to the driveshaft spline to form a splined connection. Rotational energy is transferred between the drivetrain subsystem and the driveshaft via the splined connection. The driveshaft misalignment measurement system also includes accelerometers coupled to the drivetrain configured to detect acceleration data and a flight control computer configured to measure misalignment at the splined connection using the acceleration data.

A flexible connecting rod is manufactured from a rigid material and having a substantially cylindrical hollow body, a leading segment with a securing area and a trailing segment having a trailing edge and a securing area. The body has at least one flexible center section, each having at least one slot to provide flexibility. The slot follows a sinuous, serpentine path to form a plurality of interlocking teeth that can follow a helical or a concentric path. Each slot has a proximal end spaced from the trailing segment and a distal end spaced from the leading segment. With multiple slots the proximal end of a slot can be spaced from, and separated by an inflexible section, or adjacent to, a distal end of a subsequent slot.

A flexible connecting rod is manufactured from a rigid material and having a substantially cylindrical hollow body, a leading segment with a securing area and a trailing segment having a trailing edge and a securing area. The body has at least one flexible center section, each having at least one slot to provide flexibility. The slot follows a sinuous, serpentine path to form a plurality of interlocking teeth that can follow a helical or a concentric path. Each slot has a proximal end spaced from the trailing segment and a distal end spaced from the leading segment. With multiple slots the proximal end of a slot can be spaced from, and separated by an inflexible section, or adjacent to, a distal end of a subsequent slot.

A magnetic filter is disclosed suitable for use in large heating and/or cooling systems, for example heating systems using pipework between 2 inch bore and 4 inch bore. The magnetic filter includes a separation chamber in the form of a pipe, and externally-mounted magnetic 5 assemblies which are movable from a position close to the pipe to a position spaced from the pipe. The magnetic assemblies are pivotally mounted to the pipe via a framework.

A magnetic filter is disclosed suitable for use in large heating and/or cooling systems, for example heating systems using pipework between 2 inch bore and 4 inch bore. The magnetic filter includes a separation chamber in the form of a pipe, and externally-mounted magnetic assemblies which are movable from a position close to the pipe to a position spaced from the pipe. The magnetic assemblies are pivotally mounted to the pipe via a framework.

A flexible shaft includes first and second shaft portions, first and second angular displacement couplings, and an axial displacement coupling generally extending and centered to a rotational axis. The first shaft portion extends between the first angular displacement coupling and the axial displacement coupling. The second shaft portion extends between the axial displacement coupling and the second angular displacement coupling. The axial displacement coupling includes an outer periphery, first wall attached to and extending radially between the first shaft portion and the periphery, and a second wall attached to and extending radially between the second shaft portion and the periphery. The first and second walls are resiliently flexible to facilitate axial displacement between the first and second shaft portions.