This bizarre and hard-to-find device is a purely mechanical illuminated display, which utilizes a series of slides to block light and display numbers. Each digit consists of an X and Y axis slide: the X axis slide contains all of the segment patterns needed to display numbers using the four vertical segments, and the Y axis slide contains all of the patterns needed to display numbers with the three horizontal segments. A series of cams move the slides in lock-step, opening and closing the slots in the front of the device as needed to display numbers. This display is a fully contained clock module, and includes a synchronous motor and alarm mechanism that closes a set of contacts when the alarm is tripped. Four knobs below the display allow setting of the time and alarm, as well as activation and deactivation of the alarm and manual closure of the alarm contacts.
Telechron occlusion display in operation.
Telechron occlusion display and clock mechanism, normal operation.
Telechron occlusion display, rear view. Note the three arms, which move the X-axis slides based on the position of the digit cams below.
In this partially disassembled state, the X and Y axis slides can be removed. Note the X-axis cam in the lower right of the photo.
Four of the six slides used in this display. The square slides move in the X axis, and the elongated slides move in the Y axis
Like other incandescent displays, this device can be easily upgraded with colored LEDs.