SPLIT STEMMING BAR AND SPLIT STEMMING BAR SYSTEM INCORPORATING SAME

摘要

Split stemming bar (10) includes first and second wedge members (12a,12b) having respective wedge contact surfaces (14a) and (14b). The wedge members (12a) and (12b) have a transverse profile or section in the general shape of a semi-circle so that with the services of the members (12a) and (12b) in mutual contact and the members (12a) and (12b) overlying each other, the stemming bar (10) has a circular cross section. The surfaces (14a) and (14b) are inclined in opposite directions so that the outer diameter of the split stemming bar (10) can be varied by sliding the members (12a) and (12b) relative to each other. The wedge members (12a) and (12b) are also each provided with protrusions (12a) and (12b) for mutual abutment with each other when the wedge members (12a) and (12b) are slid relative to each other in a direction which reduces the outer diameter of the stemming bar (10). By virtue of the mutual engagement of the protrusions (24a) and (24b) pulling wedge member (12a) out of the hole also drags out wedge member (12b).