Lightweight trench box

The ornamental design for a lightweight trench box, as shown.

FIG. 1 is a side elevational view of a lightweight trench box constructed in accordance with the teachings of this invention;

FIG. 2 is a top plan view of the invention;

FIG. 3 is an end view looking from the left (as viewed in FIG. 1); and

FIG. 4 is an end view of the invention looking from the right (as viewed in FIG. 1).

Patent	Priority	Assignee	Title
7559724,	Mar 17 2008		Adjustable and portable trench support

Patent	Priority	Assignee	Title
2188077,
3335573,
4056940,	Oct 26 1976	Griswold Machine & Engineering, Inc.	Trench box height adaptor
4114383,	Oct 12 1976	Efficiency Production, Inc.	Portal frame for trench box stack

Executed on	Assignor	Assignee	Conveyance	Frame	Reel	Doc
Aug 29 1977		AGL Corporation	(assignment on the face of the patent)

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