| 摘要 |
<p>Apparatus for forming multi-character messages on the surfaces of solid materials wherein an array of marker pins (88-94) are selectively pneumatically actuated from a corresponding array of solenoid actuated valves (102-104,106). The marker pins are returned to their operational ready position by a select pneumatic input (96) which performs in conjunction with a pressure limiting valve (126). Continuous monitoring of marker pin performance is carried out by a transducer (166) operating in conjunction with a monitoring duct (168) and selectively located monitoring openings (168a-168g). The marker pins readily are accessed for maintenance in consequence of their positioning within a head structure (12) having access openings at one end (78) and which is retained in position by ball lock pins (64, 65).</p> |
