| 摘要 |
756,394. Retractive switches. SOC. GENEVOISE D'INSTRUMENTS DE PHYSIQUE. March 23, 1954 [April 1, 1953], No. 8430/54. Class 38(5) [Also in Groups XXII and XXIII] A machine tool, such as a drilling or grinding machine, comprises means for measuring the positions of a slide 2 on a. bed 1 and a device for repeating the positions comprising a drum 60 carrying projections 65, 66, 67 co-operating with a control mechanism which includes two adjacent push-members 80, 81 the push-members being actuated by movement of a projection such that movement of the first member causes a slowing down of the slide and movement of both members causes stopping of the slide when the said projection is centrally between the members. Each projection or dog co-operates with the two relatively-sliding adjacent push-members 80, 81 which move a lever 87 resting on slides 88, 89, the latter carrying electrical contacts 94-99, two of which can be adjusted by eccentrics 102, 103. Movement of a lever 26 to one side or other starts a motor and energizes a drive clutch to move the slide. When the dog 65 contacts, say, the member 80, Figs. 9 and 13, the contacts 97, 98 are closed to cause a lower speed clutch to be operated, the lever 26 to be returned to neutral and a direction-indicating tell-tale lamp 105 to be illuminated. Continued movement of the slide causes the dog 65 first to push all three contacts 97, 98, 99 into contact and then to push down the member 81. As the dog begins to release the member 80, the contact 99 is released and the clutches are set for the lowest slide speed. Finally, when the dog is exactly central of the members 80, 81, the contacts 97, 98 part and the motor stops. |
