horizontally or inclined doors which might be opened via mechanical hydraulic or electrical means could also be used with various embodiments assuming that the closure included an integrated flange and hub those of ordinary skill in the art will readily be able to devise other applications in which various embodiments of the invention might be utilized it is to be understood that the terms u201c including u201d u201c comprising u201d u201c consisting u201d and grammatical variants thereof do not preclude the addition of one or more components features steps or integers or groups thereof and that the terms are to be construed as specifying components features steps or integers if the specification or claims refer to u201c an additional u201d element that does not preclude there being more than one of the additional element it is to be understood that where the claims or specification refer to u201c a u201d or u201c an u201d element such reference is not be construed that there is only one of that element it is to be understood that where the specification states that a component feature structure or characteristic u201c may u201d u201c might u201d u201c can u201d or u201c could u201d be included that particular component feature structure or characteristic is not required to be included where applicable although state diagrams flow diagrams or both may be used to describe embodiments the invention is not limited to those diagrams or to the.