Plastic-filled telescopic prod. - with plastic bands joining inner and outer steel tube

摘要

Telescopic roof support prop (1) for use in mines and tunnelling consists of an inner (4) and an outer (5) steel tube with dewatering holes which can be extended by turning the drum (14) from the outside. After reaching the final height, a building material such as a two-component plastic material with steel fibre reinforcement is injected through the spring-loaded non-return valve (67) to form a solid core (6). Three bands, only two of which are shown (7,8), are attached at one end through openings (9) at the top of the outer end and at the other end through a slot in the inner tube to a disc (10). A central band (11) joins this disc to a winding drum (14) which can be turned by a tool from outside when the prop is to be extended. All bands (7,8,11) are made of polyester cord straps. ADVANTAGE - Creates a low-cost one-way roof support which is easy to handle.