| 摘要 |
<p>1,198,839. Advancing mine roof supports. K. M. GROETSCHEL. 16 Nov., 1967 [16 Nov., 1966; 15 March, 1967], No. 52128/67. Heading E1P. In an advancing mine roof support assembly comprising an outer frame disposed on either side of an inner frame with an advancing jack 55 interconnecting some for selective advance is parallel the roof structure 27 of the outer frame is of rectangular configuration with at least its forward portion downwardly cranked to accommodate the roof structure 32 of the inner frame and both roof structures project forwardly. of the base to support the mine roof overlying the conveyor. The assembly is also provided with shields 16, 17, guide devices 40, 41 and a steering device 44 operable by a jack 47, 48 acting on a lever 50 having retaining means 52, 53. The inner frame is connected by rods 60 to conveyor which is advanced by a ram 90 pivotally connected to the outer frame. In a modification, see Figs. 4 and 5, (not shown), the roof structure of the inner frame is provided at least at the forward end thereof with a pivotal, roof-engaging plate adapted for relative longitudinal advancement and, if desired, predetermined angular positioning. Specifications 1,037,920, 1,168,792 and 51724/67 are referred to.</p> |
