More than seventy years ago, F. A. Votta, Jr., developed both the constant force springs and constant torque springs, characteristics of which are quite different from conventional ones. Those springs have been utilized still widely in fields of engineering over the world as useful mechanical elements being able to keep forces or torques constant, regardless of its extension. Thanks to its peculiarity springs have, retention of some objects at arbitrary point can be achieved. The authors can not deny that there are no experimental proof and that theoretical explanations are insufficient in his paper. In fact, there exist always certain amount of differences between our experiments and his analysis. Then authors tried to derive an appropriate equation representing the spring force, using their own ideas. However, the result authors obtained turned out, contrary to the author’s expectation, to be just the same to Votta’s, leading to verifying the validity of Votta’s expression. In addition to the above, the authors also discussed theoretically and experimentally the difference of spring forces between normal winding and reverse winding of springs around a drum. It is made clear that the spring force produced by reverse winding becomes twice that by normal one. These results are very useful to know both the spring force and torque produced in constant torque spring system, which may be introduced in a paper concerned.
