Yale & Towne Manufacturing Co., Stamford, Connecticut - 4 movements, Quad-N, v.1 with Yale No. 1 automatic bolt motor

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The difference between the Quad N version 1 and 2 is in the door design. The v.1 had a full glass design with the winding holes through the glass. It was soon discovered that glass breakage could occur from a careless insertion of the key. This was a particular problem if the operator used a key that was slightly oversized to the winding square where it would flop sideways against the eyelet hole. This was soon replaced with the half-glass design where the door metal extended over where the key holes were located. The v.1 vs. v.2 design extended to other Yale models. For their other automatic time locks designed for use with a bolt motor there was the Triple L, Triple P (a three movement version of the Quad N); for their models designed for use with manually driven door boltwork there was the Triple K, Triple O, Quad M.

The bolt motor consists of two sections. To the left is a square section which is the motor; to the right is a rectangular damper box.

The bolt motor cover is off and damper box parted from the motor. There are two redundant springs to drive the vault door bolt works. Only one is needed to do the job, just as redundancy is used in the time lock where only one of four timers is needed to put the lock off guard and actuate the bolt motor. The damper box acts as a shock absorber to mediate the sudden and violent action of the powerful spring release, thus easing the release action on the vault door's boltwork.


Perspective view of the time lock with the bolt motor cover removed. On the left is the "business end" of the motor. The square bolt between the cylinders is what pushes the vault door's bolt works open under the influence of either of the two very powerful spring. To the right is the other end of the motor bolt as represented by a pair of "T" shaped pieces, so the entire motor bolt is shaped like a sideways wishbone. The pair of bolts shown are keyed into the damper box, now removed.


The damper box is seen in the first photo with the center two pistons extended. These are fairly difficult to move as they are seated within a heavy viscous material. It's amazing that these still function smoothly after 125 or so years. Next photograph shows the winding handle for the motor springs. One can appreciate how powerful, and thus, stiff these springs are by the size of the key handle. Only one-quarter turn is needed to load the spring.


These patent drawings represent the bolt motor design and is very close to the bolt motor in this example. It appears that there are three dampening pistons in the drawing vs. the four in the actual motor, and the twin cylinders on the front are not present.


A demonstration of the Yale model Quad N time lock mounted to a Yale No. 1 automatic bolt motor. Both the Quad N and No. 1 bolt motor were Yale's largest and meant for the largest vault doors.

Quad-N, v.1, c. 1900. This was Yale's biggest and heaviest automatic time lock using the companies' largest movements, the "M" size. Weighing in at twenty two pounds it was for use in the largest vault doors, see photo below. This example, version 1, had the full glass door panel which was  replaced by 1908 with the half-glass design due to the easy breakage of the glass from careless winding. The change in glass design distinguishes the v.1 from the v.2 across much of Yale's early product line; and can be seen in the Triple L, P, Quad N, for automatic bolt motors and Triple K and O for conventional bolt work. This example was introduced in the mid 1890's and was advertised to have a combined pull exceeding seventy pounds. It was a bit of an odd promotion since the Quad M did not depend on the movements to "pull" much of anything, see demonstration video. It only needed to push a small lever aside to actuate the bolt motor below the lock.

The fact is that this model was scaled up to match the size of the larger vault doors. It would not look good for a massive door to depend upon a 'dinky' time lock to guard it even if this was a perfectly effective design. Appearance, decoration and promotion was a big part of the industry at this time; an impressive presentation to the customer played a large part in the design of time locks. The profit margins were large and so patent litigation was key, as it is today, to keep out competitors. Yale made about one-hundred of the nickel plated full glass model shown here. This author knows of no other extant, although surely some must exist. The lock is equipped with long duration 120 hour movements. Yale actively campaigned to convert their 72 hour movements as the longer durations became more popular. However, the tell-tale circular witness mark left from the larger winding gear that was mounted on on the 72 hour winding square is absent so these may be a very early set of original longer duration movements.

The time lock is mounted to the original Yale No. 1 automatic bolt motor it was installed with. The No. 1 was Yale's heaviest, most powerful bolt motor for use with the largest vault doors. The combined weight of the time lock and motor is 75 lbs. (34 kg).

Time lock only: 9 1/4"w x 6 1/4"h x 3 1/2"d. Case #38, movement #MH 128, MH 130, MH 137, MH 138. file 289
Bolt motor only: 14" w x 9"h x 3 1/2"d. Case #128
Overall: 14"w x 14 3/4h x 31/2"d

The photo below shows a large round vault door equipped with a Yale Quad N and No.1 bolt motor similar to the example above.

Yale 4mvt in vault door.jpg (124198 bytes)

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