The early hammer drill to the right was sold in the USA by Orr & Lockett Hardware Co. in 1914. The Rawlplug Mechanical Hammer was patented and sold in the UK and manufactured in the UK and Belgium. Another US maker was the Diamond Expansion Bolt Co. of New York City. Their hammer drill was patented by James T. Hoal on 4 August, 1914, U.S. Patent No. 1106306.
 |
| Orr & Lockett hammer drill |
 |
| Rawlplug Mechanical Hammer |
 |
| Rawlplug Mechanical Hammer |
 |
| Diamond drill patent |
 |
| Diamond Expansion Bolt drill, photo by Martin J. Donnelly Auctions |
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.