Sargent & Greenleaf, Rochester, New York - 2 movements, Model #2 version 1, 2 and 4.
In 1874 S&G introduced their Model #2 time lock. This was their first time lock-only model that operated directly on the bolt work of the safe. Their Model #1, which was introduced at the same time, operated by disabling the safe's combination lock and was a part of and located within the time lock case. The example below is the earliest known Sargent and Greenleaf Model #2 and the only known complete example of the first version of the Model #2 time lock. At the time it was marketed at a hefty retail price of $400 which translates into nearly $9000 today. The earliest known version of Model #3, and the Model #4 were smaller and designed to fit within tighter door configurations but were still priced the same $400 retail price. This remained the most expensive time lock until the introduction of Yale's Model #1, in 1876 with the Sunday dial attachment coming in at $450. Not surprisingly Yale's standard model, introduced in 1875 was priced at $400. The only other time locks to exceed these prices were the Consolidated Time Lock Company's Dalton Dual Guard introduced in 1884 at $500 and the combination of the Dual Guard and Permutation locks in one unit known as Triple Guard for $600 in 1888; the most expensive time lock in real dollars ever produced. Keep in mind that these prices often exceeded the value of the entire safe upon which these devices were attached!
The prominent feature of this time lock design is the rollerbolt on the lower right of the lock. When it is rotated clockwise causing the pin mounted to the tail of the roller bolt to rise, the pin will engage the notch on the drop lever which is mounted to the movement plate and controlled by the rotating dials of the time lock movements. The rollerbolt was first introduced in the James Sargent Magnetic Rollerbolt combination lock in 1866. This innovation moved the dogging action of the lock from the tumblers themselves to the fixed bolt axle, further isolating the tumblers from any attempt to read them through the boltwork. In the time lock its function is restricted to dogging the bolt work. Another interesting feature is the fact that the door is a flush mount, note the lower right hand corner of the photo above. Shortly after the introduction of their production, S&G switched to their 'clamshell' style of door having an overhang around the door edge (excepting the hinge side). This style was used throughout their numbered series of locks, model #2, #3, #4. By the time their #6 was introduced about 1910 S&G began using a flush door design the same as Yale had been using through the life of their manufacture. There was a few experiments with a countersunk door design used in their model #4 Corliss and was similar in design to what Hall and their successor Consolidated used in their case designs.
A. Model #2 version 1, (later no. 6206), 1874. What distinguishes version 1 from all other Model #2 versions are the dials which indicate hours numbered one through forty eight. However it only had mainsprings that would power it through forty six hours of power and this model was sold with instructions warning the user not to wind the the movements past 46 hours.(1) Obviously this was not a very good arrangement which probably did not reflect well on the product and so was very soon changed to the dials being numbered through forty six hours. It is interesting to note that the two examples of S&G's Model #1 both have the forty six hour dials. It is not unreasonable to believe that this example could be earlier in manufacture than the two known Model #1's or that they were later retrofitted with the forty six hour dials. Notice in the second and last photos the right hand dial has the last numeral, 48, partially blacked out with crayon reflecting this situation. Originally both were, but I removed the the covering on the right dial to better reveal the last number. The last photo also shows the stop screw as well as two open, threaded holes. Near this screw on the dial is a corresponding pin attached to the end of the wheel spoke. When the pin comes into contact with the screw the movement stops and is provided to avoid the dial from turning too far and jamming up against the snubber bar (the release lever for the bolt). Apparently there were a few trials and errors in the positioning of this part on the very early units. I've never seen additional stop screw holes on any other S&G lock. There are only two known, complete examples of Sargents' first time lock only model, the number 2.
Another feature of the very earliest locks made by S&G is the deep, rich gold filled damascene jewelling on the case and roller bolt. The earliest locks also had elaborate vine-like engraving on the movement plates as well as the dial spokes. Another change that was made very soon after the lock's introduction was to alter the way the dials were attached. Changing them from being permanently mounted to their arbors (photo three) to having them secured with a screw making servicing much easier (see example C). 6.5"h x 7.75"h x 2.75"d. Case #40, movement #43. file 91
B. Model #2 version 2, 1874. This lock is identical in all respects to the version 1 except that Sargent lowered the numbering on their dials to reflect the fact that it could only be relied upon to operate for 46 verses the 48 hours on the original version 1. There are two known versions of this model with the glass door. John Erroll's book shows another version 2 with the solid door used in coin safes making only three known survivors of the version 2 movement. 6.5"h x 7.75"h x 2.75"d. Case #129, movement #129, lock #129. file 158
C. Model #2 version 4, 1876. This lock is similar to the original time lock invented by James Sargent and first put on a vault door in 1874 (see above). Only a few of the first production run of this lock had the black enamel dials. The Model 2 had many changes over the years of it's production from 1874 through 1927. John Erroll's book divides these changes into 15 styles through this period. Although this version made for just over one year it was the first time lock to get a longer production run, thought to be between 150 to 200. One of five known completely intact examples. Formerly from the Harry Miller collection. Another example is in the John M. Mossman collection in the Museum of The General Society of Mechanics and Tradesmen, New York, NY. Case #531, movement #535. file 101
Below is an illustration from a Detroit Safe Co. catalog, c. 1875. The drawing clearly shows a model of #2 time lock still using a rollerbolt with the auxiliary bolt. Version  was the last to use this before the introduction of the "cello" style drop bolt in version  in 1877. So far I have been unable to locate an extant safe with a S&G model #2.
(1)American Genius Nineteenth Century Bank Locks and Time Locks, David Erroll & John Erroll, pg. 150