Abstract: An apparatus for closing a discharge opening (3) in the bottom (1) of a container, preferably a rotary mixing table of a processing machine, comprising a closure cover (4) which is arranged on a rotary shaft (5) through a support arm (6). The rotary shaft (5) and the support arm (6) are provided outside the container and adjacent the bottom thereof. A resilient means (8) is disposed between the closure cover (4) and the support arm (6) which are connected together by way of a hinge (7). Preferably the resilient means can be a rubber or plastic member which is faced with metal members (16, 19) and which is arranged between the closure cover (4) and a pivot bearing (9). The pivot bearing (9) is secured to the support arm (6) and has a bearing plate (11) with screw threaded bores (13, 14) for mounting at least one pressure screw (15) and an adjusting screw (17).