| 摘要 |
<p>A safety device for an aerial lift (10 fig 1) having a basket 20 with controls 23 and a foot operable safety switch 24 which activates the controls 23 comprises a tensioned wire or cord 27 proximate to the controls 23 and an auxiliary safety switch 26 whose first set of contacts are held closed in use by the cord 27, the auxiliary safety switch 26 being connected in series with the foot safety switch 24 so that in the event that the cord is distorted the contacts are changed to an open condition and the auxiliary switch 26 prevents activation of the control panel 23 and may additionally operate an alarm by means of a second set of contacts. The auxiliary switch 26 may include a signal filter which inhibits changes in the signal from the first and/or second set of contacts until a desired time period has elapsed to prevent the safety device being activated by inadvertent loads.</p> |
