Cool Tools: Tool Ergonomics
Published: December 2004
Electricians depend on a multitude of tools to build, maintain and repair electrical and voice/data/video (VDV) systems.
From a simple screwdriver to top-of-the-line power drill or sophisticated testing instrument, the best tools are engineered not only to be productive and durable, but also easy and safe to use.
Ergonomics-the science of designing things so they are efficient for people to use-is a key element in every quality tool. Often a product's ergonomic benefits are as heavily promoted as its other features.
-- Ergonomics incorporates many elements.
-- Smaller, lighter tools are easier and less tiring to use.
-- Basic tools such as wire strippers that require repeated motion are shaped to lower stress to the wrist, making extended-period usage possible and allowing workers to complete more work with less fatigue.
-- Balance, adjustable and interchangeable handles, slip-resistant grips, and isolation of vibration-especially in power tools such as hammer drills-make tools easier to use and increase productity for those who operate them.
With ergonomics, the key is recognizing the importance of the human element in the task a tool is designed to do, as well as the physical and mechanical elements of performance, observed Ed Liss, marketing manager for Bahco North America. However, the human factor has not always been a primary consideration in the design of hand tools, and many veteran electricians can recall the heavy, often awkward-to-use tools of their apprentice days.
“At one time, tools were designed on a functional basis only,” said Lee McAndrew, tooling marketing manager, FCI-Burndy. “About 20 years ago, studies started to come forth showing the cost of worker injuries and the impact they had on worker productivity. The cost of workers' compensation has risen dramatically, and the industry has demanded tools that not only perform the functional side, but also have an ergonomic asset for the worker and not just the application.”
Here, representatives of several manufacturers share their views on the importance of tool ergonomics.
Greenlee Textron, Don Shaner, director of engineering: “Changes in the work force and the demands of the workplace require that we continually look for ways to make electricians' jobs safer and easier. Tools that require a lot of manual effort are being replaced with power-assisted tools, including battery-powered cable cutters and connector crimp tools. Tool designs minimize fatigue and maximize ease of use. Rapid prototyping now allows us to touch, feel and grip tools much earlier in design-we no longer need to imagine how people will hold a tool and how it will feel to them. We make more use of end-user feedback than we ever have before. High-strength, heat-treated aluminum alloys have been in use for a long time. We are making more use of engineered plastics and composites. We position the battery to provide a balanced feel and minimize fatigue. As batteries continue to improve, electricians will begin to see more power contained in the same- or lesser-weight battery pack.”
Ideal Industries Inc., Bruce Hartranft, business unit manager: “Research documents the harmful effects of many types of motion in the workplace, and injuries to the hands, wrists, elbows and shoulders can be traced to work practices and the use of nonergonomic tools. Wire stripping, particularly on large commercial jobs, involves prolonged repetitive use of the hands. Use of ergonomic tools is critical to reducing work-related injuries, but implementing the use of these tools requires going beyond the simple act of purchasing them. Every employee needs to receive the appropriate training in proper tool use and work practices relevant to the job. In the case of wire stripping, knowledge on use of the cutting, stripping and bending features can further reduce the strain put on hands. For example, the 'thumb valley' push-zone pads design feature provides push-pad location for their thumbs better focusing the kinetic energy and reducing hand fatigue. Elastomer materials improve the control and comfort electricians have with hand tool grips. Small but critical design attributes improve tool grip-sweat-relief dimples in the surface of the grip improve control on hot work days, color-coded grips with raised letter icons speed tool selection, easy-opening pivots that smoothly operate without preconditioning reduces wrist fatigue.”
Bahco North America, Ed Liss, marketing manager: “The value of ergonomic tools is now becoming more important in the U.S., and our perception is that that trend will increase. Three of the most significant are two-component handles that allow a thin layer of cushioning material over a hard plastic handle in screwdrivers, pliers and other hand tools; hammers with handle designs that reduce the vibration and stress created when the blow is struck; and handle shapes that better conform to the shape of the users' hands. As materials, manufacturing methods, and engineering and design techniques have become more sophisticated, comfort, ease of use, and above all, safety, are incorporated into a greater number of tools. Recently the industry has especially been focusing on weight, noise and vibration and the long-term effects each has on the user.”
Robert Bosch Tool Corp., Jennifer Uzumcu, safety engineer: “Considering factors like weight, balance, gripping surfaces, control handles, noise, vibration and others, engineers strive to design tools that will allow end users to last as long as their tools. Many professionals use different tools all day long, while others use the same tool repetitiously for projects like breaking up concrete or drilling. Researchers have recognized that extended exposure to high vibration tools has negative long-term effects. In response, manufacturers have developed special vibration dampening devices for tools like rotary and demolition hammers and grinders. How tool weight is distributed is important. The introduction of materials like plastics or lighter metals decreased the weight of tools. Appropriate distribution of weight permits a user to better support the tool with less stress on the wrist and joints. Soft-grips enhance vibration reduction and allow the user to gain a better grip on the tool. Larger multifinger triggers, ambidextrous safety switches, and speed controls make general function and operation less stressful, adding to a more ergonomic tool and safer use. Keeping all tool levers, switches or other functions in close proximity has proven positive in ergonomic terms.”
Hilti Inc., Keith Kirk, market manager: “Ergonomics is an important consideration as it relates to worker comfort and worker comfort is a subset of overall productivity. Factors such as vibration control, ease of use, accessibility of switches during use, versatility in handling by having multiple grip positions, and weight and balance all contribute to worker comfort. As users place greater emphasis on productivity, comfort and ease of use, manufacturers have responded with tools that continue to make advances in these areas.
“Some of the most important are vibration control through counterbalance mechanisms and soft grips, balance by designing the center of gravity so the tool is not front or rear heavy, [and] improved power-to-weight ratios reducing tool weight,” Kirk added. “Tools have gone from metals to plastic, which reduces weight and how tool-generated heat is dispersed. It is critical to have controls that are easily accessible; convenient placement of on-off switches; easy-to-access reverse switches, etc.”
Milwaukee Electric Tool Co., Scott Bubitz, industrial engineer: “Tool ergonomics is a very important factor in the design and engineering of power tools. At their best, tools become an extension of their user's hand. In order to achieve this, attention to handle size and shape as well as tool balance is essential. Poorly designed tools cause discomfort, increased fatigue, and even cumulative trauma disorders such as carpal tunnel or tendonitis. Some of the most important advances to benefit ergonomic tool design have occurred relatively recently. Weight reductions allowed by the development of high-strength, low-weight polymers have resulted in lighter tools, which translate into less user fatigue.
“Lightweight aluminum and magnesium alloys significantly reduce weight and fatigue in power tools. Modern molding processes and computer-aided design in conjunction with these modern polymers and alloys has allowed for the production of handle shapes that can be optimized for user comfort. The introduction of thermoplastic rubber or soft grip over molding on handles has been a relatively recent introduction to the world of power tools. Its benefits include increasing the tactile grip preventing slippage of the tool in the hand as well as decreasing the vibration that is transferred to the hand by the tool.”
FCI-Burndy, Lee McAndrew, tooling marketing manager: “Much of tooling in the electrical industry deals with crimping a connector and wire together. This requires a tremendous amount of force, basically four tons and up. In the past this meant mechanical crimpers or extremely heavy and bulky high-pressure presses. Advances in material-both metals and plastics-give designers the ability to manufacture tools capable of handling job extremes while being lightweight and durable.
“Advances in battery technology make the use of battery tools more desirable not only from an application standard, but also one of safety and cost. Training in the proper use of tools is an important consideration. Training and interaction with tool users is a two-way street and provides manufacturers with valuable information regarding the needs of the industry,” McAndrew added. EC
GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at 405.748.5256 or firstname.lastname@example.org.