IT938655B - DOOR CLOSING DEVICE - Google Patents

Abstract

1357588 Door holders; remote-controlled fastenings EATON GmbH 10 Sept 1971 [10 Sept 1970] 42346/71 Heading E2A An overhead door closing mechanism comprises a pair of rod arms 12, 13 connected at a common rotary joint 14, a keeper member 25 clamped to one of said arms, at said common rotary joint, a bolt 13 movably mounted in the other of said arms and cooperable with said keeper member and an electromagnet 19 carried by said other arm and which on excitation causes the bolt to be held a position in which it restrains relative movement of the two arms. In the construction shown, the bolt includes a roller 29 which engages a notch 28 in the keeper in the restraining position. The keeper is disposed between the two arms and it is clamped to the arm 12 by tightening a nut 17 on a pivot bolt 18 which forces a shoulder of the bolt into engagement with the keeper member and clamps it to the arm 12 in any desired position. The bolt is normally held in engagement with the keeper member by a lever 35 which is pivotally mounted on the arm 13 and biased into engagement with an end portion 32 of the bolt by a spring 37; the spring also holds the lever into engagement with the core 38 of the electromagnet; however, the closing spring of the door closer 10 is sufficient to overcome the force of the spring 37 and hold the door closed unless the electromagnet is energised in which case the energisation prevents the pivotal movement of the lever 35 against the bias of the spring 37 which is necessary before the door can close. The electromagnet can be in circuit with a smoke or fire alarm which breaks the circuit of the electromagnet in the event that smoke or fire is detected in which case the door automatically closes.