Abstract A closing cover member is provided for the mouth opening of an open-ended vessel such as a pail having a rim and made of a structural plastic material having nonrigid, flexibly distortable mechanical properties, such as high-density polyethylene, the pail having a peripheral rigidifying flange rising outwardly from the exterior of the sidewall commencing uniformly below the rim and forming an acute angle with the sidewall, the outer margin of the rigidifying flange terminating in a peripheral upwardly inturned short hook flange, and the cover member having a depending marginal flange wall terminating in a conic outwardly rising peripheral flange adapted to be forcibly nested upon the rigidifying flange with the edge engaged continuously under the hook flange, whereby axial pressure within the pail tends to enhance the sealing pressure along the contact areas of the outer and inner edges of the conic flange; either the conic flange or the rigidifying flange may be rigid, i.e. made of metal, if the other is polyethylene; where resistance to internal pressure is not required, roll-edge cover members may be snapped-on under the hook flange.
A container and cover member as set forth in claim 1 wherein said mouth closing portion conformably contacts said rim when said cover member is affixed in closing relation.
Claim 2
Dependent Claim
33 words
A container and cover member as set forth in claim 1 wherein the inner margin of said annular conic sealing flange projects radially inwardly of said depending sidewall and forms a sealing protuberance.
Claim 3
Dependent Claim
31 words
A container and cover member as set forth in claim 1 wherein said inner margin of said hook flange lies in a plane spaced adjacently below the plane of said rim.
Claim 4
Dependent Claim
31 words
A container and cover member as set forth in claim 1 wherein the inner margin of said hook flange lies in a plane spaced slightly above the plane of said rim.
Claim 5
Dependent Claim
22 words
A container and cover member as set forth in claim 3 wherein said acute angle is between about 15* and about 75*.
Claim 6
Dependent Claim
18 words
A container and cover member as set forth in claim 6 wherein said acute aNgle is about 45*.
Claim 7
Dependent Claim
45 words
A container and cover member as set forth in claim 6 wherein said hook flange has an undersurface which is inclined to the upper surface of said rigidifying flange with an included angle which is a right angle or slightly less than a right angle.
Claim 8
Dependent Claim
80 words
A container and cover member as set forth in claim 2 wherein said mouth closing portion of said cover member comprises a central planar portion, an upwardly extending wall portion integrally joined with said planar portion, an annular rounded portion merging with said upwardly extending wall portion and with said depending sidewall portion, said annular rounded portion having an undersurface conformably contacting said rim when said conic sealing flange is seated with its outer margin locked under said hook flange.
Claim 9
Dependent Claim
14 words
A container as set forth in claim 3 wherein said mouth opening is circular.
Claim 10
Dependent Claim
37 words
A container and cover member as set forth in claim 3 wherein said mouth opening is rectangular in plan view having rounded corners, and said rigidifying flange comprises straight strip side portions merging with conic corner portions.
Claim 11
Dependent Claim
22 words
A container and cover member as set forth in claim 3 wherein said rim has the largest diameter of said hollow body.
Claim 12
Dependent Claim
26 words
A container and cover member therefor as set forth in claim 3 wherein said hollow body has constant cross-sectional dimensions between said junction and said rim.