CONSTANT TENSION DEVICE

摘要

A support is configured to support and apply a constant or near-constant tension onto a wire or string, such as a musical string of a stringed musical instrument. The wire is attached to a carrier that moves axially. One or more springs operate between the carrier and a point that is fixed relative to the carrier and apply a transverse spring force to the carrier. A spring angle is defined between a line normal to the axis and a line of action of each spring. The transverse spring force can have an axial force component and an axial spring rate that is a function of the spring angle. The carrier can be positioned so that the axial spring rate is zero, negative or positive. A primary spring can apply a primary force directed coaxial with the wire. If the wire changes in length the primary force will correspondingly change, as will the axial force component. The transverse spring can be selected so that the axial force component of the transverse spring approximates the change in the force applied by the primary spring so that the axial force applied to the carrier and wire remains generally constant.

主权项

1. A constant tension device, comprising:
a primary spring attached to a carrier so as to apply a primary spring force directed along an axis, the primary spring force applied to the carrier changing in accordance with a primary spring rate function as the carrier moves relative to the primary spring along the axis; a wire or string attached to the carrier and extending along the axis so that a net axial force applied to the carrier is applied to the wire or string; and a secondary spring having a first end attached to the carrier so as to apply a secondary spring force to the carrier, the secondary spring force directed transverse to the axis and having an axial component that is applied to the carrier in a direction along the axis, the secondary spring force configured so that the axial component of the secondary spring force varies in accordance with a secondary spring rate function as the carrier moves relative to the primary spring along the axis; wherein the net axial force applied to the carrier comprises the sum of the primary spring force and the axial component of the secondary spring force.