Abstract: An assembly includes at least one piston, a rotating member, a transition arm, and a mechanism. The transition arm is configured to translate between rotational movement of the rotating member and a first linear motion of the piston. The mechanism is configured to superimpose a second linear motion of the piston onto the first linear motion of the piston. The assembly can be a hydraulic (or air) pump or hydraulic (or air) motor, with the second linear motion resulting in reduced output ripple or smooth torque vs. angular rotation, respectively. Also, the assembly can be an alternator or electric motor, with the additional linear motion resulting in an ac waveform that conforms substantially to a sinewave or a back emf that conforms to the input voltage or electric waveform. In addition, the assembly can be an internal combustion engine in which the second linear motion results in the pistons lingering about top dead center during the combustion process.

Abstract: A joint for positioning between first and second elements includes an outer member and an inner member. The first and second elements are arranged for linear motion along a common axis. The outer member is configured for movement relative to the first and second elements along a first axis perpendicular to the common axis, and the inner member is mounted within the outer member for rotation relative to the outer member about a second axis perpendicular to the first axis and the common axis and for movement relative to the outer member along the second axis. The outer member is restrained from movement along the second axis. The outer member defines first and second parallel flat sides. Each flat side defines a plane perpendicular to the common axis. The outer and inner members each defining an opening for receiving a drive arm.

Abstract: An assembly includes a cylinder (232) and a piston assembly (212) housed within the cylinder and configured for reciprocal motion relative to the cylinder. The piston assembly and cylinder include a magnet (230) and coil (234) configured to undergo relative motion of the piston assembly and cylinder. The assembly includes a transition arm (214) and a rotating member (222) coupled to the piston assembly by the transition arm. The reciprocal motion is linear in space and sinusoidal in time.

Abstract: An assembly includes a piston and a transition arm coupled to the piston. The position of the transition arm is adjustable to vary a stroke of the piston. A balance member is adjustable relative to the transition arm to counterbalance the transition arm in varying positions. A control rod is coupled to the transition arm and the balance member. Linear movement of the control rod moves the transition arm in a first direction to change the stroke of the piston and moves the balance member in a second direction substantially opposite the first direction to counterbalance the transition arm. A method of counterbalancing a variable stroke assembly includes moving a transition arm coupled to a piston to vary a stroke of the piston, and moving a balance member in a direction substantially opposite to the direction of movement of the transition arm to counterbalance the transition arm.

Abstract: A variable compression piston assembly includes a plurality of pistons, a transition arm coupled to each of the pistons, and a rotating member mounted for pivoting movement to slide along an axis of the drive member. Movement of the rotating member relative to the drive member changes the compression ratio of the piston assembly. An engine assembly includes first and second piston assemblies mounted back-to-back and 180° out of phase. A joint for positioning between first and second pistons includes an outer member and an inner member. The outer member is configured for movement relative to the pistons along a first axis perpendicular to the common axis of the pistons. The inner member is mounted within the outer member for rotation relative to the outer member about a second axis perpendicular to the first axis and the common axis.

Abstract: A joint for positioning between first and second elements includes an outer member and an inner member. The first and second elements are arranged for linear motion along a common axis. The outer member is configured for movement relative to the first and second elements along a first axis perpendicular to the common axis, and the inner member is mounted within the outer member for rotation relative to the outer member about a second axis perpendicular to the first axis and the common axis and for movement relative to the outer member along the second axis. The outer member is restrained from movement along the second axis. The outer member defines first and second parallel flat sides. Each flat side defines a plane perpendicular to the common axis. The outer and inner members each defining an opening for receiving a drive arm.

Abstract: A variable compression piston assembly includes a plurality of pistons, a transition arm coupled to each of the pistons, and a rotating member mounted for pivoting movement to slide along an axis of the drive member. Movement of the rotating member relative to the drive member changes the compression ratio of the piston assembly. An engine assembly includes first and second piston assemblies mounted back-to-back and 180° out of phase. A joint for positioning between first and second pistons includes an outer member and an inner member. The outer member is configured for movement relative to the pistons along a first axis perpendicular to the common axis of the pistons. The inner member is mounted within the outer member for rotation relative to the outer member about a second axis perpendicular to the first axis and the common axis.

Abstract: A variable compression piston assembly includes a plurality of pistons, a transition arm coupled to each of the pistons, and a rotating member mounted for pivoting movement to slide along an axis of the drive member. Movement of the rotating member relative to the drive member changes the compression ratio of the piston assembly. An engine assembly includes first and second piston assemblies mounted back-to-back and 180° out of phase. A joint for positioning between first and second pistons includes an outer member and an inner member. The outer member is configured for movement relative to the pistons along a first axis perpendicular to the common axis of the pistons. The inner member is mounted within the outer member for rotation relative to the outer member about a second axis perpendicular to the first axis and the common axis.

Abstract: An assembly includes a piston and a transition arm coupled to the piston. The position of the transition arm is adjustable to vary a stroke of the piston. A balance member is adjustable relative to the transition arm to counterbalance the transition arm in varying positions. A control rod is coupled to the transition arm and the balance member. Linear movement of the control rod moves the transition arm in a first direction to change the stroke of the piston and moves the balance member in a second direction substantially opposite the first direction to counterbalance the transition arm. A method of counterbalancing a variable stroke assembly includes moving a transition arm coupled to a piston to vary a stroke of the piston, and moving a balance member in a direction substantially opposite to the direction of movement of the transition arm to counterbalance the transition arm.

Abstract: A piston assembly includes first and second pistons, a transition arm coupled to each of the pistons, and a rotating member rotating in a first direction about a first axis. The transition arm includes a drive member coupled to the rotating member off-axis of the rotating member. A first counterbalance is mounted to rotate in the first direction, and a second counterbalance is mounted to rotate in a second direction opposite the first direction. The second counterbalance rotates about a second axis offset and parallel to the first axis. Alternatively, the second counterbalance rotates about the first axis. A method of counterbalancing a piston assembly includes mounting a first counterbalance to the piston assembly to rotate in the first direction, and mounting a second counterbalance to the piston assembly to rotate in the second direction.

Abstract: An assembly includes a piston and a transition arm coupled to the piston. The position of the transition arm is adjustable to vary a stroke of the piston. A balance member is adjustable relative to the transition arm to counterbalance the transition arm in varying positions. A control rod is coupled to the transition arm and the balance member. Linear movement of the control rod moves the transition arm in a first direction to change the stroke of the piston and moves the balance member in a second direction substantially opposite the first direction to counterbalance the transition arm. A method of counterbalancing a variable stroke assembly includes moving a transition arm coupled to a piston to vary a stroke of the piston, and moving a balance member in a direction substantially opposite to the direction of movement of the transition arm to counterbalance the transition arm.

Abstract: A piston assembly includes first and second pistons, a transition arm coupled to each of the pistons, and a rotating member rotating in a first direction about a first axis. The transition arm includes a drive member coupled to the rotating member off-axis of the rotating member. A first counterbalance is mounted to rotate in the first direction, and a second counterbalance is mounted to rotate in a second direction opposite the first direction. The second counterbalance rotates about a second axis offset and parallel to the first axis. Alternatively, the second counterbalance rotates about the first axis. A method of counterbalancing a piston assembly includes mounting a first counterbalance to the piston assembly to rotate in the first direction, and mounting a second counterbalance to the piston assembly to rotate in the second direction.

Abstract: A piston assembly includes first and second pistons, a transition arm coupled to each of the pistons, and a rotating member rotating in a first direction about a first axis. The transition arm includes a drive member coupled to the rotating member off-axis of the rotating member. A first counterbalance is mounted to rotate in the first direction, and a second counterbalance is mounted to rotate in a second direction opposite the first direction. The second counterbalance rotates about a second axis offset and parallel to the first axis. Alternatively, the second counterbalance rotates about the first axis. A method of counterbalancing a piston assembly includes mounting a first counterbalance to the piston assembly to rotate in the first direction, and mounting a second counterbalance to the piston assembly to rotate in the second direction.

Abstract: A variable compression piston assembly includes a plurality of pistons, a transition arm coupled to each of the pistons, and a rotating member mounted for pivoting movement to slide along an axis of the drive member. Movement of the rotating member relative to the drive member changes the compression ratio of the piston assembly. An engine assembly includes first and second piston assemblies mounted back-to-back and 180° out of phase. A joint for positioning between first and second pistons includes an outer member and an inner member. The outer member is configured for movement relative to the pistons along a first axis perpendicular to the common axis of the pistons. The inner member is mounted within the outer member for rotation relative to the outer member about a second axis perpendicular to the first axis and the common axis.

Abstract: A joint for positioning between first and second elements includes an outer member and an inner member. The first and second elements are arranged for linear motion along a common axis. The outer member is configured for movement relative to the first and second elements along a first axis perpendicular to the common axis, and the inner member is mounted within the outer member for rotation relative to the outer member about a second axis perpendicular to the first axis and the common axis and for movement relative to the outer member along the second axis. The outer member is restrained from movement along the second axis. The outer member defines first and second parallel fiat sides. Each fiat side defines a plane perpendicular to the common axis. The outer and inner members each defining an opening for receiving a drive arm.

Abstract: A variable compression piston assembly includes a plurality of pistons, a transition arm coupled to each of the pistons, and a rotating member mounted for pivoting movement to slide along an axis of the drive member. Movement of the rotating member relative to the drive member changes the compression ratio of the piston assembly. An engine assembly includes first and second piston assemblies mounted back-to-back and 180° out of phase. A joint for positioning between first and second pistons includes an outer member and an inner member. The outer member is configured for movement relative to the pistons along a first axis perpendicular to the common axis of the pistons. The inner member is mounted within the outer member for rotation relative to the outer member about a second axis perpendicular to the first axis and the common axis.

Abstract: Wound strings for a musical instrument include inharmonicity compensation. A portion of the wound string, preferably at one or both ends thereof, includes a concentric winding. The concentric winding has a length l.sub.comp given by: ##EQU1## where D.sub.s is the outer diameter of portions of the wound string remote from the compensating winding, D.sub.comp is the diameter of the wound string at the compensating winding, d is the diameter of the core wire and l.sub.bare is the length of the bare end of the string.

Abstract: A wound musical string includes a core wire and a wrapped wire covering about the core wire. End turns of the wrapped wire covering are coextensive portions of transition sections of the core wire. The transition sections have equilateral triangular, square or other cross sections such that the cross section exhibits equal principal moments of inertia. Consequently the inharmonicity of the string about two axes will be the same and the string will not produce false beats.

Abstract: Wound strings for a musical instrument include inharmonicity compensation. A portion of the wound string, preferably at one or both ends thereof, includes a concentric winding. The concentric winding has a length l.sub.comp given by: ##EQU1## where D.sub.s is the outer diameter of portions of the wound string remote from the compensating winding, D.sub.comp is the diameter of the wound string at the compensating winding, d is the diameter of the core wire and l.sub.bare is the length of the bare end of the string.

Abstract: A method and apparatus for tuning a musical instrument. Measurements are made of the inharmonicities of three notes (e.g., F3, A4 and C6 in a piano). One of the notes (e.g. A4) is a standard note that is to be tuned to a standard frequency. The measured inharmonicities of these notes determine a slope of a tuning curve and a position to intercept the standard note frequency according to the following: ##EQU1## Y(p,N) is the cents deviation relative to the equally tempered scale of partial p of note N, F is a factor by which the inharmonicity increases per octave taken from the measurement, B(N) is the inharmonicity of note N, and B(STD) is the inharmonicity factor of a standard note (e.g., A4 at 440 Hz).