Spring Counterbalance Patents (Class 362/402)
  • Patent number: 4080530
    Abstract: An equapoised lamp comprising a lamp head mounted upon an arm assembly which is counterbalanced by springs enclosed within square tubes which are components of the arm assembly. The arm assembly has a lower pair of parallel arms which are pivoted at their lower ends to a swivel bracket which turns about a vertical axis in a fixed bracket. Each of those arms is pivoted at its upper end to a floating bracket which has pivoted to it a similar upper pair of parallel arms. A lamp assembly is mounted upon the other end of the upper pair of arms by a universal joint assembly. The arms are tubular, and each pair forms a parallelogram by virtue of the pivotal connections with the respective brackets. A coil spring is enclosed within one of each pair of tubes which exerts a counterbalancing effect upon its pair of arms. A nylon shoe is mounted upon the free end of each spring and enclosed within the tube. The shoe transmits the counterbalancing force from the spring to the adjacent bracket.
    Type: Grant
    Filed: October 27, 1976
    Date of Patent: March 21, 1978
    Inventor: Jens Christian Krogsrud