Position indicator for a multiple character marking device

Abstract

Abstract This disclosure relates to a marking device with a plurality of marking wheels for marking slabs, billets or the like with a group of characters. Each marking wheel has a plurality of characters on the outer periphery and character selection is accomplished by rotating the marking wheel until the desired character on the wheel periphery is in marking position. Each wheel has a ratchet on one side that is actuated by a pawl connected to an actuating slide. The pawl on the actuating slide engages a segment of the ratchet and rotates the marking wheel for character selection. On the other side of the wheel there is a spiral cam with different preselected radial dimensions for each of the characters. A linear transducer is biased against the cam surface and generates a voltage signal that is proportional to the radial dimension of the portion of the cam aligned with the transducer to thus indicate the particular character in the marking position. The voltage signal from the transducer is compared with fixed reference voltages and when the voltages match, a relay is actuated to indicate the character on the wheel in marking position. The circuitry includes a logic section to count sequentially so that a transducer malfunction at the steeply sloping portion of the cam between the longest and shortest dimension of the cam cannot produce an incorrect character indication.

Inventors

• 👤 Edwin W Speicher
• 👤 Charles E Fry Jr

Bibliographic Details