Demolition tool

摘要

The present invention is a projectile type demolition tool. A projectile with an enlarged upper cross-sectional area is slideably mounted within and extendable from an inner cylinder. The lower portion of the projectile is extendable through a guide connected to the bottom of the inner cylinder. Upon pressing a working end of the projectile against a work piece to be broken, the projectile recedes upward in the inner cylinder until the enlarged upper area moves above a source of low pressure gas connected through the inner cylinder. The low pressure gas continues to move the projectile upward in the inner cylinder to a cocked position. In the cocked position, a reduced area upper portion of the projectile acts against a moderately high pressure gas injected into a combustion chamber. Thereafter, a high pressure gas is created by an internal combustion in the combustion chamber, which high pressure gas drives the projectile downward into the work piece. During downward movement, the entire upper surface of the projectile is exposed to the high pressure gas. The high pressure gas is exhausted through ports in the inner cylinder into an annulus formed by an outer cylinder, and thereafter through a base support between the outer cylinder and the guide. Any lateral forces that are exerted on the projectile as it breaks the work piece are countered by the cylinders and guide.