Rallonge à double articulation

摘要

750,229. Mine roof supporting bars. GUTEHOFFNUNGSHUTTE STERKRADE AKT.- GES., [formerly GUTEHOFFNUNGSHUTTE OBERHAUSEN AKT.-GES.]. Jan. 28, 1953 [Jan. 28, 1952], No. 2472/53. Addition to 738,819. Class 20(2). The pivot joint between two mine roof bars described in the parent Specification is modified in that the pivot eye 3, Figs. 1, 2 on one bar 1 which receives the pin 4 of the advance bar 2 is provided on a plate 18 mounted on a vertical axis 16 on the bar 1 for lateral rotatable movement. Alternatively the eye 31, Figs. 7, 8 is provided with an arcuate bearing surface 60 at its outer end, the pin 4 on the bar 2 being first rested on the bottom flange of the bar 1 adjacent the eye 31 with the bar 2 in a laterally inclined position, whereupon the bar 2 is pivoted upwards and a locking bolt 51 on the bar 2 with an arcuate end piece 501 slid forwards to engage the bearing surface 60 as shown in Fig. 8, the bar 2 then being swung horizontally into line with the bar 1, so that the pin 4 engages in the eye 31 as shown in Fig. 7. Fig. 7 also shows the locking bolt 51 retracted and a locking wedge 28 supporting the bar 2. An apertured abutment plate 14, Figs. 1, 2 provided. on the end of the bar 1 limits the lateral movement of the plate 18, the pin 4 of the bar 2 also passing through the aperture 17. A longitudinally displaceable locking bolt 5 on the bar 2 engages in a recess 6 in the plate 18 to hold the bar 2 in the horizontal plane while swinging it into line with the bar 1. A locking shoe wedge 8, Fig. 4, guided by the lower flange of the bar 1 is then driven over the extremities of the pin 4 on the bar 2.