Variable length reinforcement to control seat back performance

Abstract

A modified seat frame provides a seat back frame mounting reinforcement which can be conveniently varied in length and strength to vary the allowed degree of deflection and energy absorption provided by the seat back upon rear impact.

1 . A modular seat frame comprising:
 first and second risers;   a partial perimeter tube for a seat back frame supported from the first and second risers at joints formed between opposed ends of the perimeter frame and open necks in the first and second risers; and   reinforcement members located in the joint overlapping portions of the partial perimeter tube and the necks of the first and second risers.   
   
   
       2 . A modular seat frame as claimed in  claim 1 , further comprising:
 the reinforcement members being open channel members fitting outside of the partial perimeter tube and inside of the necks and being shaped to conform to the section shapes of the partial perimeter tube and neck sandwiched between the two.   
   
   
       3 . A modular seat frame as claimed in  claim 2 , further comprising:
 the reinforcement members having lengths chosen to control strength of the joints and to control deformation of the seat back frame upon rear impact into the seat back frame.   
   
   
       4 . A modular seat frame as claimed in  claim 2 , further comprising:
 the reinforcement members having holes located to control strength of the joints and to control deformation of the seat back frame upon rear impact into the seat back frame.   
   
   
       5 . A modular seat frame as claimed in  claim 3 , further comprising:
 installation on a school bus.   
   
   
       6 . A modular seat frame as claimed in  claim 4 , further comprising:
 installation on a school bus.   
   
   
       7 . A modular seat frame as claimed in  claim 2 , further comprising:
 the reinforcement members being welded to the ends of the perimeter tubes.   
   
   
       8 . A modular seat frame as claimed in  claim 2 , further comprising:
 the reinforcement members being welded to the inside surfaces of the open necks.