Abstract: A piston arrangement comprising: a piston; a rotatable element, rotatable about an axis, having a first engagement profile; and a mechanism comprising: a first connecting element connected to the piston; a second connecting element pivotable about a fixed point and pivotally connected to the first connecting element; and a second engagement profile coupled to the first and/or second connecting element, configured to mechanically engage and disengage with the first engagement profile of the rotatable element.

Abstract: A piston arrangement includes a piston movable within a cylinder in reciprocating motion along a piston axis, a rack movable with the piston, a sector gear configured to engage and disengage the rack and rotatable around a sector gear axis, a track adapted to rotate relative to the cylinder around a track axis of rotation, the piston being coupled to the track. The sector gear and the track are coupled in rotation. The track may have a shape such that the movement of the piston coupled to the track is substantially non simple harmonic. Also, an internal combustion engine comprising the piston arrangement.

Abstract: A piston arrangement including a track and a piston moveable within a cylinder; wherein the track is adapted to rotate relative to the cylinder about an axis of rotation and has a cam surface and an edge surface extending away from the cam surface; wherein the piston is coupled to the track by a follower running on the cam surface; wherein the cam surface is shaped such that, as the track moves relative to the cylinder, the piston head moves in reciprocating motion within the cylinder in accordance with the path of the cam surface; wherein a stabilising element is connected to the piston, the stabilising element extending below the piston head and comprising a contact surface which engages the edge surface of the track.

Abstract: A piston arrangement is provided. The piston assembly includes a track and a piston moveable within a cylinder. The track is rotatable relative to the cylinder about an axis of rotation and has a cam surface and an edge surface extending away from the cam surface. The piston is coupled to the track by a follower running on the cam surface. The cam surface is shaped such that, as the track moves relative to the cylinder, the piston head moves in reciprocating motion within the cylinder along a piston axis in accordance with the path of the cam surface. The piston axis is perpendicular to the track axis of rotation. A stabilizing element is connected to the piston, the stabilizing element extending below the piston head and comprising a contact surface which engages the edge surface of the track.

Abstract: A piston arrangement is provided. The piston assembly includes a track and a piston moveable within a cylinder. The track is rotatable relative to the cylinder about an axis of rotation and has a cam surface and an edge surface extending away from the cam surface. The piston is coupled to the track by a follower running on the cam surface. The cam surface is shaped such that, as the track moves relative to the cylinder, the piston head moves in reciprocating motion within the cylinder along a piston axis in accordance with the path of the cam surface. The piston axis is perpendicular to the track axis of rotation. A stabilizing element is connected to the piston, the stabilizing element extending below the piston head and comprising a contact surface which engages the edge surface of the track.

Abstract: A piston arrangement including a track and a piston moveable within a cylinder; wherein the track is adapted to rotate relative to the cylinder about an axis of rotation and has a cam surface and an edge surface extending away from the cam surface; wherein the piston is coupled to the track by a follower running on the cam surface; wherein the cam surface is shaped such that, as the track moves relative to the cylinder, the piston head moves in reciprocating motion within the cylinder in accordance with the path of the cam surface; wherein a stabilising element is connected to the piston, the stabilising element extending below the piston head and comprising a contact surface which engages the edge surface of the track.

Abstract: A piston arrangement including a track and a piston moveable within a cylinder; wherein the track is adapted to rotate relative to the cylinder about an axis of rotation and has a cam surface and an edge surface extending away from the cam surface; wherein the piston is coupled to the track by a follower running on the cam surface; wherein the cam surface is shaped such that, as the track moves relative to the cylinder, the piston head moves in reciprocating motion within the cylinder in accordance with the path of the cam surface; wherein a stabilising element is connected to the piston, the stabilising element extending below the piston head and comprising a contact surface which engages the edge surface of the track.

Abstract: A piston arrangement comprising a cylinder, a piston head movable along a piston axis within the cylinder, a con rod, and a track having a path; wherein the con rod has a first end which is coupled to the piston head and a second end which is coupled to the track; wherein the track is adapted to be moved relative to the cylinder and is shaped such that, as the track moves relative to the cylinder, the piston head moves in reciprocating motion along the piston axis in accordance with the path of the track; wherein the path of the track is shaped such that piston head displacement is non simple harmonic with respect to displacement of the track relative to the cylinder. Also an internal combustion engine including the piston arrangement.

Abstract: A piston arrangement including a track and a piston moveable within a cylinder; wherein the track is adapted to rotate relative to the cylinder about an axis of rotation and has a cam surface and an edge surface extending away from the cam surface; wherein the piston is coupled to the track by a follower running on the cam surface; wherein the cam surface is shaped such that, as the track moves relative to the cylinder, the piston head moves in reciprocating motion within the cylinder in accordance with the path of the cam surface; wherein a stabilising element is connected to the piston, the stabilising element extending below the piston head and comprising a contact surface which engages the edge surface of the track.

Abstract: A piston arrangement comprising a cylinder, a piston head movable along a piston axis within the cylinder, a con rod, and a track having a path; wherein the con rod has a first end which is coupled to the piston head and a second end which is coupled to the track; wherein the track is adapted to be moved relative to the cylinder and is shaped such that, as the track moves relative to the cylinder, the piston head moves in reciprocating motion along the piston axis in accordance with the path of the track; wherein the path of the track is shaped such that piston head displacement is non simple harmonic with respect to displacement of the track relative to the cylinder. Also an internal combustion engine including the piston arrangement.