to the bar 124 and torsion springs 126 the second bar 130 and torsion springs 132 operate in the same way as the bar 124 and torsion springs 126 in this configuration the parallel rows of spring assemblies are coupled together through a gear mechanism 140 as shown in fig1 16 the secondary spring assembly is connected via a set of three gears 140 a 140 b and 140 c which translates the rotation of the sidewall 106 from the main spring assembly to the secondary spring assembly as shown in fig1 and 16 the gear mechanism 140 translates the load from one assembly to the other so they act in parallel this system provides the additional torque needed at the lower 45 degrees of rotation where the first spring assembly can struggle the present invention is not limited to two spring assemblies coupled together by a single gear mechanism it is possible that multiple rows of spring assemblies can be utilized requiring multiple gear mechanisms as depicted in fig1 15 the second bar 130 and torsion springs 132 of the secondary spring assembly do not extend the entire length of the sidewall 106 and are located towards the ends of the.