Volume 35, Issue 4 (July 2007)
A Biaxial Load Cell Design for Simultaneous Measurement of Horizontal and Vertical Spring Forces in Sinuous Spring-Supported Seating
Sinuous springs are the most commonly used method of seat support in upholstered furniture. The dynamics of load transference by these springs to the furniture frame members has not been thoroughly studied. Rational strength design of sinuous-type upholstered furniture frames, especially their seating support systems, requires information concerning the magnitudes and directions of spring loads on spring supporting rails. These values are important for frame designers to be able to adjust member sizes and materials and select appropriate fasteners. Presently, furniture design largely depends on trial and error. A load cell was conceived, designed, and verified which can determine horizontal and vertical components of a spring load. Preliminary results showed that the average initial spring tension on each load cell, with no external loading applied to the springs, was 46 lb. (205 N) horizontal. For some situations, the horizontal load components actually decrease when a person comes to rest on the seat. Vertical and horizontal loading is greatest on the center three springs of the seat which used five, equally spaced springs in this paper.