Offered for sale a nice pair of Tower's Double Locking Leg Irons Circa 1904. I have cleaned the locking mechanisms and tested thier operation with the included key(reproduction key). during testing these cuffs worked as they were designed to(read description below for details on the operation of the double locking mechanisms). The Tower's Double Locking mechanism was patented in Aug of 1879. In Sept of 1882 there was a subsequent patent. This pair of leg Irons do not contain either of these patent stamps but do contain the words "Tower's Double lock". This attribute indicates to me a production date after 1904 when John Tower's company became part of Union Hardware Company of Torrington, Connecticut. These Leg Irons are in excellent condition and still retain most of the original plating. However, years of use have created scratches, dings and plating loss(please see the pictures provided). These Leg Irons also have a 12 link chain between the cuffs. This is an excellent pair of working antique Leg Irons that would compliment any handcuff collection. There is a single key provided with this sale. Reproduction keys are available on-line but it appears to be a violation of Ebay policies for me to tell you where these keys are available. If you send me a message I will give you the information on where additional reproduction keys are available. I will ship the cuffs in an open unlocked condition.
History of the Towers Double Lock Handcuff. The introduction of the adjustable ratchet principle by Adams and later Phelps solved one major problem in handcuff design, but it introduced another. For the ratchet to work the locking bolt or catch had to be spring loaded. This allowed the bow to be freely closed to suitable setting to fit the prisoner's wrist. The problem was that the spring loaded bolt was susceptible to shimming. To shim a handcuff one inserts a watch spring or other fine bit of metal down the inside of the bow until it rest against the bolt or catch. One then closes the cuff one on additional notch catching the watch spring between the catch and the ratchet notches. This prevents the catch from engaging and the bow can be sprung open. Tower realized this problem from the beginning. Indeed the main claim of his 1874 patent for the round bow was that a round or oval bow would be harder to shim open than a square bow.
Despite the round bow the Tower bottom key and single lock models could be shimmed by a determined prisoner with a proper bit of metal. To permanently solve the problem Tower introduced the Tower "Double Lock" handcuff. Patented on August 19, 1879 this handcuff has a much more sophisticated lock mechanism. The lock had two settings. In the single lock mode it acted just like the single lock model. To open the lock the key was inserted an rotated one half turn to the left, counter-clockwise. However, if the key was turned instead to the right, a full turn clockwise, then the lock was put into a double locked setting. The catch or bolt was now frozen, the handcuff bow could not be opened, but it also could not be further closed. This prevented one from shimming open the cuff. To remove the double lock the key had to be reinserted and turned a full turn to the left, counter-clockwise. Another half turn to the left would then open the cuff completely.
The earliest Tower double lock handcuffs are marvels of engineering. They were manufactured to very high tolerances. The key hole has a very tight opening requiring a key with a very thin wall. The bow also fits into the lock case with a very close fit. Indeed there is so little gap it is hard to imagine any prisoner successfully shimming open the cuff even without the double lock. One could reasonably argue that these handcuffs are the finest handcuffs ever made in America, at least in terms of adherence to quality standards of manufacturing. Unfortunately these comments apply only to the earliest double lock models. Double lock Tower hand cuffs were manufactured for over fifty years. Later models were not manufactured to such high standards. - eBay (9 June 09)