Yale & Towne Manufacturing Co., Stamford, Connecticut - 2 movements,
Type A patent model prototype
The complete line of Yale Type A through G time locks pictured from left to right. The A was a unique prototype
piece. Only the
Type B through E series went into production.
The G was only made as salesman's samples. Since the Type A was a prototype and at the present time only one Type
C and complete G has been found, those facts makes this collection unique in that it
contains the complete set of all the examples. No records for or examples of
a Type F are known.
Front elevation of the Type A.
Front elevation of Type A with bezel cover removed. Look carefully at the holes
drilled around the perimeter and note the imperfections, especially in the one
at the 6 o'clock position, indicating a hand built model around the movement
supplied by E. Howard.
The Yale Type A prototype with screw down glass bezel attached. Made sometime
between 1886 and 1888.
The main components of the Type A, glass screw-down bezel, movement base and
case with dog release. It is difficult to discern from the design of the release
if it was meant to operate on conventional bolt work or an automatic. There is a
center gear fixed to the case which meshes with the two side gears located on
the rear of the movement plate allowing the two watch springs to be wound
simultaneously when the movement base is rotated counterclockwise.
These two photos show the release pin, here at hour three. The knurl knob
unscrews and the pin can be removed and moved to any of the hour positions
numbered from 1 to 48. The protruding pin below the rear plate engages the
release lever. According to the patent, a second pin can be used in case of
overwinding, so if the lock is overwound by 5 hours a second pin can be inserted
five hours prior to the regular closing hour to make the lock open on time. This
overwind correction via a pin is replicated in the later Type B and all Type C
Here is a comparison of the Type A with a Chicago Time Lock, Co. Perfection Model 1, 1886.
They are both identical in diameter. The Perfection Model 1 was the smallest
time lock made at the time. An examination of both time locks movements shows
that they are identical 48 hour E. Howard movements. Even the style of the swirl
damascene on the upper movement plate is similar. The only differences are the
lack of the slot on the edge for a fence to drop into, a smaller center hole and
a different opening configuration to view the balance wheels.
According to the patent information describing the Perfection Model 1, in
addition to that time lock being used as a stand-alone time lock for
emergency vault doors and small money chests, the lock was also designed to
be incorporated directly onto the wheel pack of a combination lock, and the
slot cut into the lock's edge for the combination lock's fence as well as
the hole in the middle corroborates this, first photo. The fact that the
Yale Type A is the identical size, and upon closer examination contains an
identical E. Howard movement makes for an interesting speculation on whether
this lock was originally ordered from Howard by the Yale company to explore
their own design for a time lock mounted directly to a wheel pack. It would
seem that if this were the case the research did not bear fruit just as this
was never fully developed by the Chicago time Lock company. More likely the
similarity between the two movements is a coincidence and the Yale company
was supplied this movement by Howard after reviewing their specifications as
a short cut to designing a completely new prototype for Yale's research into
their line of time locks. This is supported by the patent drawings submitted
by Henry and Herbert Stockwell, #363,918, May 31, 1887, below.
The first drawing shows the Type A exactly as found in the example shown on
this page. Note on the upper left hand corner the word "Model", indicating
that there was a patent model, the example here is that model. What is interesting is that Yale was contemplating a three
movement version within this same configuration (sheet 2), which was adopted
in the larger production models as shown in the patent designs in the
section on the Type B.
To have three movements within the 3
diameter space of the patent model could have been done with a single plate
movement and that is what the patent model was with a two movement design.
But if the goal was to create a modular design using 'off the shelf' pocket
watch movements, this would not have been possible at the time; standard
pocket watch movements were too large. The maximum watch movement diameter
would need to be less than 1
¼" diameter; not impossible to make but
certainly not in any watch company's current inventory.
The Stockwell's had already fully fleshed out the design for using pocket
watch movements in a modular fashion in
two subsequent patents that were submitted on the very same day. Most likely
those designs were not fully formed at the same time as the Type A, but were
later patented simultaneously. This confirms that the time lock shown here
was indeed the Type A prototype of the production series Type B through E
and likely had no connection with the movement used in the Chicago Time Lock
Co. Perfection models other than that E. Howard supplied the movement.
Here the Yale Type A prototype is examined and compared to a very similar
time lock made earlier by the Chicago Time lock Co. The Type A was a test
bed for the eventual production models of the Type B, C, D and E models.
Yale Type A patent model, c. 1887. This was an experimental prototype for the
later production models of the Type B, C, D and E. It is of a different
design from those models but does contain the essential rotating movement
base which was the basis for the Type B and C. This was later improved upon
with the introduction of the D and E by fixing the table to the case and
using a central arbor attached to a sun gear that drove the three planet
watch movement winding gears. The front of the arbor allowed for the
attachment of a dial pointer and insertion of a winding key greatly
improving the design.
The A prototype used an identical E. Howard movement that was used
by the Chicago Time Lock Co., earlier in 1886 in their Perfection Models 1
and 2. It is unknown if the movement used here was simply supplied by E.
Howard as an answer to Yale's specifications or if Yale had some connection
with the Chicago Time Lock Co. in a cooperative effort. It would seem to
this author that the given the litigious nature of the time lock industry
still prevalent at the time that the latter is unlikely. Case 3 3/4"
diameter and base plate 3 3/4"h x 3 3/4"w file