Tools and Machinery of the Granite Industry

Chronicle of the Early American Industries Association, Inc., The, Jun 2006 by Wood, Paul

Steel granite-working hammers came in three basic varieties. Some hammers, like the drilling hammer, were designed to be swung and to strike steel graniteworking tools of various kinds; other hammers were designed to be swung and to strike the granite directly, and finally, some hammers were designed to be held in place against the granite and to be struck by another hammer. In any situation where steel strikes steel, the hammer striking face is both tempered to provide impact resistance and beveled to reduce the chance of splintering. Granite workers are now required to wear protective glasses or goggles to prevent steel splinters from flying into their eyes. Repeated use causes striking faces to "swell" and thus need to be periodically ground back into their original shape. Hammer handles were usually made of hickory and were of various lengths, cross-sections, and shapes depending on the hammer size and use. Today, the buyer can order fiberglass handles as an option for most granite-working hammers.

Joseph Couch of North Bridgewater, Massachusetts, was issued the first patent for a steam-powered rock drill in 1849 (Figure 23). The patent describes a reciprocating percussion steam-powered rock drill. The drill, which weighed several thousand pounds, was mounted on a portable wheeled frame and could be adjusted to any angle from horizontal to vertical. Power was imparted to the drill bit from a steam cylinder by a gear and crank mechanism. A cam and wedge device grasped the drill bit during its forward motion and released it at its moment of impact with the stone. This was the first drilling mechanism that did not depend solely on gravity for the drilling stroke, and therefore, the first one that could be applied to other than vertical drilling. The drill bit was rotated after each impact. In 1852, Joseph Fowle of Boston, Massachusetts, was issued a patent for a less cumbersome version of the Couch drill. Fowle's design included the important innovation of the drill bit as an extension of the piston rod.

Charles Burleigh of Fitchburg, Massachusetts, and others were issued an 1866 patent for a number of improvements to the basic Couch/Fowle design-resuiting in the first practical and reliable steam drill (Figure 24). It was successfully used to drill the Hoosac Tunnel, the first mechanically bored American tunnel. Later, Burleigh bought the Fowle patent, which his drill infringed, and organized the Burleigh Rock Drill Co. In 1871, Simon Ingersoll of Brooklyn, New York, was issued patents for a feed rod/plunger/ratchet/wheel-nut combination that produced an automatic feed, for a supporting tripod drill stand with independently adjustable legs, and for a spiral bar to rotate the drill bit during operation (Figure 25). Henry Sergeant of New York City was issued an 1873 patent for a steam or pneumatic drill in which the drill bit was an extension of the piston rod. Sergeant claimed the improvements-rotating valves, cushioning piston stop, a new mechanism for revolving the drill bit, and automatic feed.