The story of electricity goes back thousands of years, however mankind wasn’t able to do much with it until the 1700s to the 1800s, and really the 1800s are when the biggest strides for the groundwork were laid by greats such as Alessandro Volta, George Ohm, Michael Faraday, and James C. Maxwell. These giants came up with many of the theories and equations that made electrical engineering and equipment possible. By the late 1800s Europe had already developed the VDE Standard for safety, meanwhile Thomas Edison(’s team of inventors) and Nikola Tesla were making electricity practical and affordable for the populace at large. Of course, with these advancements, tradesmen had to come from somewhere to install and work on the infrastructure. It’s a no brainer that these tradesmen needed tools to do the work with. Somewhere along the line somebody invented insulated tools, which is not surprised because the concept of insulation from electricity had been around for a while.
The problem though, is that it’s quite difficult to narrow down who invented the first insulated tool and even harder to figure out how many electricians died or were seriously injured before it was decided to make the first insulated tool. It’s the author’s opinion, in the absence of other evidence, that the first attempt at an insulated tool was probably an insulated rubber glove followed by dipping the tools into some sort of insulating rubber. Hard to say, but it wasn’t too long after electricity started to spread from the labs of Edison and Tesla that one of the first insulated tools was patented.
While it’s not clear who invented the first insulated tool or when, the earliest patent for insulating a tool appeared in 1907 and was invented by George E. Wood. Wood was in the tool industry and was thought to eventually have become the owner of G. E. Wood Tool Co. which was said to have later been bought out by Stanley. Wood held a number of patents, mostly related to screwdrivers, but his contribution to insulated tools was a “device,” made of rubber or another insulating material and could be added or removed to a screwdriver as needed. This rubber piece was to cover parts of the shank, the socket and of course the handle. Better than nothing, but by today’s standards it seems quite precarious. It would be a good ten years though before someone else came along and decided to cover the majority of the tool with insulation to the relief of electricians everywhere.
There were a few other interesting innovations over the years. John Albert Weaver came up with a spring action insulated screwdriver that would retract into the insulated sheath when not in use. John Russell Foley came up with a similar design in the 30s without the spring action and the retracting ability. His take on insulated tools appears to be that the tool is just covered in an insulating material leaving only the working surface exposed. These attempts at insulating tools were pretty good, however they weren’t perfect.
In 1934, Victor A. Ryan on behalf of Electro-Technical Coatings, Inc. came up with an even safer design to combat safety issues in conditions when a lot of moisture was present. In his patent, Ryan relates that because hand tools get coated with moisture due to weather, work environment in manholes or sweat from the workman’s hands, “serious and fatal accidents” have occurred. His response was to go back and essentially redesign the insulated tool from scratch. This insulated tool made use of insulated “sheds and discs” in addition to insulating material to trap electrical current and protect the worker. The tool sort of had ridges along its side which increased surface area to impede current as it traveled to a worker’s hands. With this patent, the entirety of the tool except the working surface or tip was covered with the insulation material. This particular patent is for a screwdriver, but it’s described as being usable for other tools like most patents for insulated tools. The material used to make this tool would have been a high di-electric rubber which was as much for its durability when dropped as for its insulating properties.
Probably because the design Ryan made is a bit clunky, and probably because the materials for insulating were improving, another design was patented in 1959 by Earle F. Stockman. Stockman referenced all those who came before him to make the tool less cumbersome and safer. This design looks much more like a normal screwdriver and this design actually bears a strong resemblance to the tools made by Klein and Ideal today. The process for making this tool seems to be pretty similar to what many manufacturers use today. What Stockman added to the tool is explained in depth on the third page of the patent, but seems to be the tool has a handle with a recess inside where the inner end of the tool and the tip of the tool coming out of the other end. It doesn’t sound really that groundbreaking, but it must have been a big enough change to grant his patent.
Of course as we’ve progressed technologically and identified new issues and new solutions insulating technology has improved as have safety standards and testing to ensure that insulated tools do their job. New developments are still happening, and developments from the early 2000s have led to what companies like Klein sell now. It’s definitely awesome to see even briefly how insulated tools started and have evolved, and it will be interesting to see where they go from here, especially with new materials and nanotechnology.