| 摘要 |
PURPOSE:To prevent damage of a travel driving part and drop of the rate of time in service of an automatic unit, which travels along a circulating rail at a constant speed, by furnishing the unit with a switch for stopping at the optimum position and by judging as abnormal traveling when the time for passing between metal pieces on the rail side has esceeded a certain set value. CONSTITUTION:In the event of any abnormal travel, an automatic ball lifting machine 3 does not move till a position, in which a neighboring switch PRs is mating with a metal piece 11, even though the set period on an abnormal travel sensing timer T1 has passed, so that the timer T1 will go out and the normally open contact T1a in its circuit be closed. Thus a relay CR3 is actuated, and the normally open contact CR3a is closed and put into self-holding condition. Now an abnormality indicator lamp L in the circuit XII will light up and the normally open contact CR3b in the circuit I is opened to demagnetize an electromagnetic contact device MS1 for motor, and then the travel clutch MC is disconnected and the brake MB is put in service to stop the automatic ball lifting machine 3. Now inspections shall be made and any possible breakdown can be well prevented according to this arrangement. |
