SHIELD-CARRYING ROOF SUPPORT UNIT

摘要

It is an object of the invention to provide an improved shield-carrying roof support unit which has a linkage for adjusting the elevation of the cap while the pivotal connection between the cap and the shield is constrained to move substantially at right angles to the base frame. The provision of auxiliary links having pivotal connections at properly selected points results in a linkage which has a precisely defined configuration and avoids an overloading of the pivotal connections such as could occur in known shield-carrying roof support units of the same kind.