Patent ID: 7837413

Claim:
An adjustable spreader bar for securing oppositely spaced first and second panels of a trench box, the spreader bar comprising: a first pipe having first and second opposing ends, an outside diameter and a plurality of indexed openings spaced for selective engagement, each indexed opening passing through the first pipe, and the first end of the first pipe being removably attachable to the first panel; a second pipe having first and second opposing ends and an inside diameter greater than the outside diameter of the first pipe for a telescopic fit of the second ends of the first and second pipes along a longitudinal axis, the first end of the second pipe being removably attachable to the second panel and the second pipe having an adjustment screw portion with an outer thread and an elongated, grooved opening therethrough having a length substantially aligned with said longitudinal axis of the telescopically fitted pipes; a sleeve threadably attached to the thread of the adjustment screw portion of the second pipe, the sleeve having an inner surface with an inner sleeve channel formed with opposing channel walls and an opening passing through the sleeve at the channel, the sleeve opening has a cover with an inside arc that substantially matches a contour of the sleeve channel in said inner surface; and a locking pin to pass through the sleeve opening, the grooved opening of the second pipe and a selected indexed opening of the first pipe, wherein the locking pin has a pin length and fitted ends to seat in said sleeve channel within the inner surface, so that when the sleeve is turned along the thread of the adjustment screw portion of the second pipe, the first pipe is forced by the locking pin along the grooved opening by one of the channel walls to change the length of the telescoping pipes to extend and the other channel wall to shorten, in order to adjust the spaced relationship between the trench panels.