Abstract: A coal/coke sample is heated under controlled circumstances as a step in determining content of volatile matter. The sample is placed in a crucible having a lid and which is suspended by means of a crucible holder in a heating cavity of a furnace. The invention provides precisely, mechanically guiding the crucible holder and crucible into and out of the cavity to prevent inadvertent touching of the cavity wall by the crucible and thus also to prevent possible dislodging of the lid and spoiling of the sample. The crucible holder is secured to a lid of the furnace, and the furnace lid is guided along upwardly extending guide rods. Lifting and lowering of the lid may be manually. Instead, it may be hydraulically or pneumatically.

Abstract: A cylindrical "shell and plug" assembly has the plug rotatably received within the shell. The plug has a central rear shaft and an engagement portion thereon. The engagement portion has a pie-shaped stop member and a pie-shaped engagement member. A connecting member rotatably held within the shell has an inner engagement that can engage the pie-shaped engagement member and an operation key slot capable of receiving an end of an operation key. The plug can be rotated until the engagement member is positioned behind the flange to retain the plug with the connecting member, and the plus can be rotated so that the engagement member can be positioned away from the flange, thereby permitting the plug to become disengaged from the connecting member.