Environmental seals for multidirectional control levers

Claim 1

In an apparatus having wall means having an opening defined by an edge wall portion, and a movable member extending through and being transversely movable across said opening, and sealing structure for sealingly closing said opening about said movable member including a first closure element extending laterally outwardly from said movable member for movement directly therewith, a second closure element disposed between said first closure element and said wall means and having a first surface portion sealingly slidably engaging said first closure element and a second surface portion sealingly slidably engaging said wall means outwardly about said opening, said second closure element having an opening through which said movable member extends and which is substantially larger in cross section than the portion of the movable member extending therethrough, and means biasing said closure elements into slidable sealing engagement with each other and said second closure element into slidable sealing engagement with said wall means, the improvement comprising a stop flange on said second closure element arranged to engage said edge wall portion of the wall means in a limit position of the second closure element for limiting the movement of said second closure element transversely across said wall means opening, the transverse extent of said elements being preselected to be, in all transverse directions across said wall means opening, cumulatively greater than the transverse extent of said wall means opening whereby said two closure elements maintain said wall means opening effectively sealingly closed in all positions of said transversely movable member.