| 摘要 |
728,984. Fire-resisting doors. MANNESMANN AKT.-GES. Feb. 13, 1953 [Feb. 15, 1952; July 25, 1952], No. 4157/53. Class 20 (3). A fire-proof door for airraid shelters comprises two layers 33, 34 of fire-resisting material made of gypsum with a support of fibrous material or cardboard and secured together, e.g. by glue, the layers being enclosed by steel plates 35, 36 joined, preferably by welding, at the edges to form a stop flange 37 which when the door is closed contacts limbs 20a, 20b of a door frame 20. The door is equipped with three latch-type locks disposed half-way up, at the top, and at the bottom of the door and operated together by a bar 25 having slots 28 to engage operating pins 29. The bar is accommodated in a channel 26 which is accessible by means of one or two cover plates, not shown, which close one or both ends of the channel. The locks are introduced through openings in the front vertical rail of the frame, the middle lock being secured to the vertical rail of the frame by straps 30 and the upper and lower locks, the lower lock not being shown, being secured by straps 31 to the vertical rail and by screws 32 to the horizontal rail of the frame. In a modification the door consists of two layers of fire-resisting material having a frame Z- shaped in cross-section and a steel plate on the outside of the door which is folded over the frame at the edges. The door is reinforced with transverse bars of Z-section which are secured by one limb, e.g. by spot welding, to the steel plate, another limb engaging between the two layers of fire-resisting material. In an alternative arrangement the frame is of T-section and the steel plate is arranged on the inside of the door. In a further modification the door consists of three layers of material and the frame is composed of a combined Z- and a T- section, the steel plate being located between two of the layers of material and the Z reinforcing bars being secured to the plate. The reinforcing bars may be used as supporting means for locks or bolts. |
