Lightweight trench box

- AGL Corporation
Skip to: Description  ·  References Cited  · Patent History  ·  Patent History
Description

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).

Referenced Cited
U.S. Patent Documents
2188077 January 1940 Dowd
3335573 August 1967 Ward
4056940 November 8, 1977 Fisher
4114383 September 19, 1978 Nieber
Patent History
Patent number: D252950
Type: Grant
Filed: Aug 29, 1977
Date of Patent: Sep 18, 1979
Assignee: AGL Corporation (Jacksonville, AR)
Inventor: William F. Birchfield (Little Rock, AR)
Primary Examiner: A. Hugo Word
Attorney: Stephen D. Carver
Application Number: 5/828,879