Movable open stairway for theatre - mounts string rails on T=shaped column heads including pin joined parallelograms setting treads horizontal,申请号FR19780035322-传众专利搜索

Movable open stairway for theatre - mounts string rails on T=shaped column heads including pin joined parallelograms setting treads horizontal

申请公布号：FR2444138(A2)

申请号：FR19780035322

申请日期：1978.12.15

申请公布日期：1980.07.11

申请人：

BOSSON JACQUES

分类号：E04F11/025;E04H3/12;(IPC1-7):04H3/22;04F11/12

主分类号：E04F11/025

摘要：<p>The movable open staircase is used for theatrical purposes, having a collapsible metal framed construction, and includes a pin-jointed parallelogram mechanism which sets the treads (21, 31) horizontal whatever the string rail (12) inclination. Telescopic posts (16) on trolleys each have a high levellcross bar (24) termination in stub axles (23) and fixed horizontal cantilever arms (37). Each axle locates the foot of a bracket (34) which is welded to the relevant rail, the head of the bracket being pinned (P) to a side gusset (32b) of a primary tread plank (21). A pin-jointed (39, 30) link (38) connects the free end of each arm to the higher end of each gusset to complete the mechanism.</p>