Chicago Time Lock Company, Chicago, Illinois, Perfection Model 1 and Model 2

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The time lock cover is a separate, removable cap and is elaborately engraved by the E. Howard Watch and Clock company.

The bolt dog is in the open position given the movements are at zero. The safe bolt is allowed to slide through the rectangular opening. The blued lever is 3". I have done steel bluing and it is extremely difficult to achieve a consistent color throughout such a large part, especially before the invention of precision temperature-controlled furnaces.

The tri-oval-shaped metal escapement covers are rotated open to reveal the twin gold balance spring wheels.


The first photo shows a close up of one of the movement's balance wheel. Next one can see how very thin the time lock is. Without the cover the lock is only 3/4" deep.


These two photos again show how small the entire time lock is in relation to my hand. This is the smallest two movement model time lock known. If one were to compare total volume it would be smaller than the single chronometer lock by the Hall (later Consolidated) Safe & Lock Company which would qualify as the next in line.

Following the success of the Gem time lock, Henry Gross, E. W. Neff, and a group of investors founded the Chicago Time Lock Company to produce and sell Gross's newest design represented by his patent #321,893 dated July 7, 1885. On March 1, 1886, Chicago Time Lock placed an order with E. Howard for one hundred "double Neff movements" to be made with gold hairsprings and serial numbered  from 1. The result based on Gross's latest patent, was the Perfection time lock (see patent drawings below). (1) A small time lock has the advantage of being able to fit on smaller doors especially those inner doors within a safe where an additional layer of protection is desired. This may have also been intended for the small emergency door that was sometimes provided on larger vaults in the event the main door malfunctioned (see photo end of page below). But the most interesting thing Mr. Gross planned for, and what is not generally known and which is found within the text of his patent reveals the reason this lock has such a curious design. Why round and so thin? Why is there a hole in the middle when the lock is clearly meant to be secured by the four holes for screws in mounting flange? Why the strange cut out in the rim?

The answer is that Mr. Gross planned this to be able to function as an additional tumbler with a combination lock. Within the patent he states "My present invention has for its object, first, to provide a simple and effective construction of time lock suitable for general use in connection with the lock mechanism or bolt work of safes and vaults, and, second, to arrange the time lock mechanism within a suitable casing of such form that it may be applied and used as one of the tumblers of an ordinary permutation-lock." In the day and within the industry, a combination lock was called a permutation lock. So here we have revealed the reason the lock is designed the way it is. Look at the patent drawings below. On page one is the same lock but without the outer mounting flange. Without the flange it can be used in this way and the photos below show how this is done when mated with a Hall size #4, their largest, five tumbler wheel pack, also called a curb in industry parlance.


Now the design makes sense. Take away the mounting flange and the lock is 3 1/4" diameter, the tumblers are 2 7/8" so the difference in the diameter between the two is only 3/8" and the radius, which is the critical factor only 3/16". While the distance the fence is usually held above the wheel pack is pretty close, usually no more than 1/8" or so, there is no reason the fence could not be held an additional 3/16". And the cut within the lock not only fits the width of the tumbler notches perfectly, but is also the exact depth. So when the fence is dropped into all the aligned tumblers it will rest evenly on all the tumblers including the time lock. Of course when the time lock is 'on guard' the dark lever as seen in the third photo would be over the slot and prevent the fence from engagement. So we have a built in time lock within the combination lock itself. This surly qualifies as the state of the art in miniaturization for the industry at this time. To this author's knowledge this has never been tried before or afterward, and likely never was. As it turns out this application probably was never made it into production. The few perfection time locks known all were created with the mounting flange and meant to be used as a regular time lock as envisioned on page two of the patent. If  this configuration was ever actually made it would surely have been preserved. Still a pretty neat idea.

Model 1. 1886. The first type of Perfection, serial numbered 1 to 100, had a nickel-plated, fully removable bronze lid and two forty-eight hour movements housed in a round nickel-plated bronze case. The dials are numbered through forty-six hours, but the indicator can be fully wound back to "0" for a total running time of forty-eight hours. The trioval-shaped metal escapement covers rotate around hinge pins, revealing the escapement for observation. The winding arbors abut the enamel dials and a single mounting hole runs through the case center. Three examples of of this first type of Perfection  time lock are known. This is the same example as featured in the book American Genius, page 226. (1). 3 1/4" dia., with mounting flange 4 1/2", 3/4"d without cover" 1" with cover on. Case number unknown, movement #98. file 191

Model 2 c, 1890. At some point after 1890, Chicago Time Lock designed a revised version of its perfection time lock, retaining the major aspects of the design but incorporating a number of minor improvements. The lid was now hinged and the metal escapement covers were now were now replaced with glass bezels. The winding arbors were positioned further from the enamel dials, possibly to prevent damage to the dials, and the central mounting hole was replaced with a mounting plate. This model still featured a two forty-eight hour movements, which were now made by an unknown maker rather than by E. Howard and this is reflected by the absence of that company's attribution on the inscription on the cover. (1)

The slightly revised version started with serial number 101 (see next example below). The lock at only 1" wide and just over 3 1/4" in diameter making it one of the smallest dual movement time locks made. Approximately fifty of this second style of time lock were made and only two are known in complete condition, (having the inscribed lid attached; they apparently were easily torn off). 3 1/4" dia., with mounting flange 4 1/2", 3/4"d with cover open" 1" with cover closed, movement #123. file 176

                                     Perfection Time Lock.jpg (501772 bytes)

                                      Perfection Time Lock2.jpg (734397 bytes) B

B. Same as above but with additional linkage attached to a bolt dog mounted behind the lock. The original lid has been lost, movement #101. file 113


Henry Gross's patent drawings, #321,893, July 7, 1885.

Below are photos of a Perfection Model 2 from the John H. Mossman collection at the General Society of Tradesmen and Tradesman museum, New York, NY.


Perfection Model 1 and 2 in the Harry Miller collection, Nicholasville, KY. The date on the label is wrong. Chicago Time Lock did not come into existence until 1885, the Perfection Model was introduced in 1886.

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(1) American Genius Nineteenth Century Bank Locks and Time Locks, David Erroll & John Erroll, pp 226-227