Abstract: A spring shoe, and also in particular a spring, as well as a method of returning energy to a user, are provided. In one embodiment, a method and apparatus stores foot strike energy and releases it after a slight delay, when it will exert a force on the user which includes a forward component. This is accomplished in an embodiment by a spring in the sole which has a decreasing spring force, such that the force required to compress the sole decreases for all or part of the compression displacement as the spring is compressed.

Abstract: A spring shoe, and also in particular a spring, as well as a method of returning energy to a user, are provided. In one embodiment, a method and apparatus stores foot strike energy and releases it after a slight delay, when it will exert a force on the user which includes a forward component. This is accomplished in an embodiment by a spring in the sole which has a decreasing spring force, such that the force required to compress the sole decreases for all or part of the compression displacement as the spring is compressed.

Abstract: A novel engine for producing power from a temperature differential with additional benefits of low cost, high efficiency, quiet operation minimal wear of components, and the ability to produce power or cooling from low grade heat sources.

Abstract: An energy transfer machine, for example, a positive displacement internal combustion device, has a fixed or rotating outer housing, an internal rotating carrier and one or more inner rotors with rotational axes which are offset from the inner rotor carrier rotational axis. Circumferentially expandable projections from the outer housing and rotor mesh with each other to define variable volume chambers.

Abstract: An energy transfer machine, for example, a positive displacement internal combustion device, has a fixed outer housing, an internal rotating carrier and one or more inner rotors with rotational axes which are offset from the inner rotor carrier rotational axis. Projections from the fixed outer housing and rotor mesh with each other to define variable volume chambers. In another energy transfer machine, in which the outer housing may be fixed or rotating, projections of the rotor are expandable within cylinders defined by projections of the outer housing.

Abstract: A novel engine for producing power from a temperature differential with additional benefits of low cost, high efficiency, quiet operation minimal wear of components, and the ability to produce power or cooling from low grade heat sources.

Abstract: An energy transfer machine, for example, a positive displacement internal combustion device, has a fixed or rotating outer housing, an internal rotating carrier and one or more inner rotors with rotational axes which are offset from the inner rotor carrier rotational axis. Circumferentially expandable projections from the outer housing and rotor mesh with each other to define variable volume chambers.

Abstract: An energy transfer machine, for example, a positive displacement internal combustion device, has a fixed outer housing, an internal rotating carrier and one or more inner rotors with rotational axes which are offset from the inner rotor carrier rotational axis. Projections from the fixed outer housing and rotor mesh with each other to define variable volume chambers. In another energy transfer machine, in which the outer housing may be fixed or rotating, projections of the rotor are expandable within cylinders defined by projections of the outer housing.

Abstract: An energy transfer machine, for example, a positive displacement internal combustion device, has a fixed or rotating outer housing, an internal rotating carrier and one or more inner rotors with rotational axes which are offset from the inner rotor carrier rotational axis. Circumferentially expandable projections from the outer housing and rotor mesh with each other to define variable volume chambers.

Abstract: A spring shoe, and also in particular a spring, as well as a method of returning energy to a user, are provided. In one embodiment, a method and apparatus stores foot strike energy and releases it after a slight delay, when it will exert a force on the user which includes a forward component. This is accomplished in an embodiment by a spring in the sole which has a decreasing spring force, such that the force required to compress the sole decreases for all or part of the compression displacement as the spring is compressed.

Abstract: An energy transfer machine, for example, a positive displacement internal combustion device, has a fixed outer housing, an internal rotating carrier and one or more inner rotors with rotational axes which are offset from the inner rotor carrier rotational axis. Projections from the fixed outer housing and rotor mesh with each other to define variable volume chambers. In another energy transfer machine, in which the outer housing may be fixed or rotating, projections of the rotor are expandable within cylinders defined by projections of the outer housing.

Abstract: An energy transfer machine, for example, a positive displacement internal combustion device, has a fixed outer housing, an internal rotating carrier and one or more inner rotors with rotational axes which are offset from the inner rotor carrier rotational axis. Projections from the fixed outer housing and rotor mesh with each other to define variable volume chambers. In another energy transfer machine, in which the outer housing may be fixed or rotating, projections of the rotor are expandable within cylinders defined by projections of the outer housing.