| 摘要 |
827,618. Mine roof supporting bars. KLONNE, A.. [trading as KLONNE, A., [Firm of]]. Class 20(2) In mine roof supporting bars engaging end to end by a fork 2 and a tongue 3 and connected by a pivot pin 4 rigidly connected to a wedge 5 for locking the bars together, the wedge comprises a longitudinal rib 12 increasing in depth towards the narrower end of the wedge. A rotatable ring 8 having radial lugs engaging grooves 6 in the pin 4 retains the pin and wedge captive. The wedge 5 has striking surfaces 9, 10 at its ends. |
