GB833298A - Fluid operated door actuating mechanism - Google Patents

Abstract

833.298. Door operating appliances; remotely operated fastenings. HUBBELL Inc., H. Dec. 9, 1957, No. 38241/57. Classes 44 and 65(1) A door actuating mechanism includes fluid operated means for moving the door and other means comprising a pair of pivotally connected levers located over a master cylinder which is connected to the fluid operated means, the application of pressure to the levers causing a flow of fluid from the cylinder to cause the fluid operated means to first unlatch the door and then open it. The master cylinder comprises a fluid filled bellows 53 resting on a base member 52 to which are pivoted two channel shaped levers 55, 56 loosely pivoted together at 58, the arrangement being covered with a flexible mat 60 and disposed as a treadle at the approach to the door. Pressure on the mat by an approaching person causes fluid to pass along the pipe 36 to a passage in a housing 27 at one end of door operating cylinder 20 which is pivoted at its ends to the door 10 and to the door frame 12. From the passage the fluid passes both to a cylinder 40 to release the door latch 15 and to the cylinder 20 to open the door. Springs 59 return the levers 55, 56 to their unloaded position when the person has moved past the treadle, and springs 44, 61 respectively then close the door and reset the latch as the fluid returns to the bellows, the return flow from the door operating cylinder being diverted by a check valve 30 in the housing to flow past a restricting valve 35 which controls the closing speed of the door.