| 摘要 |
Arch frame corner units have first and second end regions of respectively first and second, dissimilar, curvatures, so that the arch frame face can be erected with the two corner units of a pair selectively in a first relative orientation in which the said first end regions are disposed adjacent one another or in a second relative orientation in which the said second end regions are disposed adjacent one another, so that the arch frame face can extend over either a first or a second predetermined width. <IMAGE> |
