[Fig. 12ª] is a perspective view showing how two of such modified expansion coils may be connected;
[Fig. 13] is a front elevation showing my invention applied to another form of force storage mechanism;
[Fig. 14] is a plan view of same, on lines 14—14 of [Fig. 13];
[Fig. 15] is a rear elevation on lines 15—15 of [Fig. 14];
[Fig. 16] is a vertical section on lines 16—16 of [Fig. 14];
[Fig. 17] is an enlarged detail of part of the apparatus shown in the upper portion of [Fig. 16];