The Hall's Infallible Lockout Protection™ system is illustrated. The blue armature shown coming from the lower right hand corner of the time lock case is part of that system. The first photo shows where the dual fences are located in the combination lock. The fence marked A. located at the 12 o'clock position is for the regular combination known to the safe's owner. The fence marked B. located at the 9 o'clock position is the secondary fence using the "secret combination" that is known to the Consolidated company and is used only in the event that there is a failure of the time lock to bypass the time lock. In that event the Consolidated company telegraphs the safe owner the bypass combination and it is first dialed in and the time lock is disabled through the activation of that fence. Next the normal combination must be dial in to ultimately open the safe.

The second photo shows a close up of the secondary fence. Here one can see the row of five screw studs as well as another row of empty, threaded holes. If someone was familiar with the construction of the Hall's Premier lock equipped with the Infallible system it would be possible to deduce the secret combination via a subtractive formula derived from the regular combination. In this example, in order to make the lock manipulation quick and easy, the combination is 60, 60, 60, 60, 60. The secret combination is 40, 40, 40, 40, 40. So knowing this one could use the subtraction of 20 from the regular combination to deduce the secret one. This fence, as illustrated in Flint's patent, allows one to move the five studs so as to add a lot more guess work to that formulaic deduction since it is no longer a simple subtraction of a single factor from the regular combination. The movement of a stud changes the combination by 2. Remember, that if someone is trying to bypass an intact, running, time lock, the automatic reset system, which is also a part of Flint's patent, puts the time lock back on guard between five to ten seconds after the bypass combination is dialed in, preventing one from entering the normal combination in time to bypass a working time lock. This fence makes this nearly impossible to do so in time unless one knows the configuration of the studs as well as the subtractive formula. As shipped from the factory all the five studs are left in-line. Any qualified service tech can change these locations so the secret combination is altered and is thus only known to the safe's owner, completely eliminating the possibility of collusion between an employee of the Consolidated company and one who knows the regular safe combination. Along with the automatic reset found within the Infallible System the time lock was extremely reliable and secure even with only a single time lock movement. The Infallible system was so reliable and effective that it became the basis for a large segment of their time locks. The cost of time lock movements was the single largest cost component of a time lock. So having a reliable time lock that could utilize only one movement and still be reliable gave the Hall's / Consolidated company a cost advantage over other makers that used two movements; and they all did. Of course these single movement time locks could only be used with the Infallible system and this was only found within the Hall's line of combination locks. However, Hall was the dominant maker of combination locks at this time. But as time went by the redundancy provided by two or more movements did supplant the single movement Infallible system. One reason was the fact that these had to be used with the Hall's line of combination locks, whereas later designs generally worked on the safe's bolt work, allowing those to operate across all lines of safe configurations. Another was the cost of movements declined, the advent of modular designs and the fact that redundant movements were easy to understand in the context of security. See video below for a demonstration of the Infallible Lockout Protection System™.

This video first shows a demonstration of the Hall's Infallible Lockout Protection™ system. Next a demonstration of the Hall's Infallible Chronometric™ device. Hopefully this video will clearly reveal how the Infallible system works why the Hall / Consolidated company's single movement design was so ingenious and successful despite the obvious lack of movement redundancy.

The first patent page is from Kook and Hall's 1879 application and illustrates their initial Infallible system. The next two pages are from Flint's 1883 application and contains two important improvements to the Infallible system. The first is the permutation fence and the second the reset system. The third was his new design for dogging the boltwork.

In 1883, the Consolidated Time Lock Company produced a time lock patented by Benjamin Flint that dogs the boltwork rather than the attached time lock's fence. This was an unusual design for consolidated, a company with more than ten years of success marketing time locks that controlled an attached combination lock. The design features single-movement Infallible Lockout Protection System™. The the mechanism to act directly on the boltwork requited an addition of the armature projecting from the right lower corner of the time lock case.

This example is paired with a Joseph Hall Premier size #3 five tumbler safe lock. There is no record of how many of these double-acting time locks were made by Consolidated. This is the only known surviving example and is the same as illustrated in John Erroll's book. (1)  4 7/8"w x 4 5/8"h x 2 5/8"d, case# 2558, movement #2558, combination lock, 6"w x 4"h x 2 1/2"d, bolt #2313. file 198

Below are photos of a similar time lock and Hall Premier combination lock but issued in the conventional configuration. Look carefully at the third photo. Here the lock's bolt has the normal slotted design equipped with a clevis pin to attach to the safe's bolt work which can just be seen attached to it.