AS 1294
Description
When the AS 1287 is enlarged from 10 1/2 to 11 1/2 lines in diameter, the result is caliber AS 1294, a windup movement from Switzerland that was utilized in the USA by Benrus under their own caliber designation, Benrus DH22.
base plate
It is easy to see that this pallet lever movement is expertly crafted - all important bearings are fitted with synthetic rubies.
base pate with minute wheel
The gear train architecture reflects the state of the art of the era — the 1940s and 1950s — as evidenced by the use of a central minute wheel, driven directly by the mainspring barrel, which is mounted beneath its own bridge.
gear train
The AS 1294 features a central seconds indication. The wheel train configuration required for this was still relatively tall, as it was executed with a third wheel, a central seconds wheel driven directly by it, and an escape wheel. The multitude of stacked wheels did not yet allow for a flatter construction.
side view of the gear train
The screw balance, beared in the exhibited specimen within a proprietary Benrus shock-protection system, operates at a period-appropriate, slow rate of 18,000 semi-oscillations per hour and is adjusted directly at the hairspring key.
AS 1294: Dial side
The Benrus-proprietary shock protection system is also visible on the dial side, offering protection at least against vertical shocks. More modern shock protection systems, such as Incabloc, would also provide protection against lateral shocks; however, this is not the case in the configuration shown here.
Elsewhere, one can also observe the yoke winding system, as well as a cap jewel for the escape wheel bearing.
In the lab
Timegrapher result
With a defective mainspring and significant water damage, it was clear that it could not present a particularly good picture on the timegrapher. Consequently, a more precise regulation was foregone.| horizontal positions | |||
|---|---|---|---|
| dial up | -111 s/d | 197° | 0.4ms |
| dial down | -81 s/d | 199° | 0.4ms |
| vertical positions | |||
| crown right (12 up) | -50 s/d | 128° | 1.4ms |
| crown up (3 up) | -210 s/d | 132° | 1.3ms |
| crown left (6 up) | -280 s/d | 128° | 0.6ms |
| crown down (9 up) | -123 s/d | 131° | 1.2ms |
Technical data
| Manufacturer: | AS |
| Caliber: | 1294 |
| Caliber base: | AS 1287 |
| Size: | 11 1/2''' (measured: 25,6mm) |
| A/h: | 18000 |
| Number of jewels: | 15 |
| Escapement: | Pallet lever |
| Balance types: | monometallic screw balance (two legs) |
| Shock protection(s): | Benrus |
| Balance bearing / direction hairspring: | Counterclockwise |
| Moveable stud: | no |
| Adjust mechanism: | Hairspring key |
| Construction: |
|
| Construction type: | solid construction |
| Winding mechanism: | yoke winding system |
| Setting lever spring: | 2 holes |
| Attachment of setting lever: | screwed |
| Features: |
|
| References: | Ebauches: I 1949 53 Feilner: Bl.20 762 Flume: 1952 6 |
| Inventory number: | 24056 |
Usage gallery
Benrus gents watch with container case