High-quality tools typically have a robust design to withstand the demand of its operators. To meet this need, the tool bodies are usually very rigid. This rigidity, coupled with the moving internal mechanisms, can introduce vibration, which is transferred from the tool to the operator.
And, prolonged use can cause operator discomfort and lead to early fatigue, affecting the comfort and productivity of the operator. Fortunately, you can calculate, manage and minimize power tool vibration to help keep construction workers comfortable and more productive.
Tool Vibration Factors
There are several factors that may increase a worker’s potential exposure to vibration. The following are a few factors and how to mediate or reduce the associated risks.
- Tool maintenance and use—Tools that are not properly used and maintained according to the manufacturer’s instructions will wear faster or become broken, resulting in increased vibration. Overly worn or loose parts may begin to rattle inside the tools, causing increased vibration during use.
- Old power tools—Vibration-reduction technology in the construction industry is a fairly new concept and a newly added tool feature. There are still tools in use that do not address this factor. Older tools were not equipped with vibration-dampening devices. Additionally, due to age and unknown maintenance history, older tools may also have worn or loose parts.
- Power tool design and selection—Even new tools can expose employees to excessive vibration if they are not designed for reduction. Vibration research has focused on key areas, such as vibration-reduction technology and hand-positioning design.
Active Vibration Reduction
Through research and development, Hilti has worked to help minimize power tool vibration using active vibration reduction (AVR) systems. This technology reduces vibration by up to two-thirds compared to conventional tools, allowing the products and tools to be used longer.
The AVR system works to help reduce vibration to the operator rather than just to the tool itself, and it does so in many ways, including:
- The motor is isolated from the external housing through a suspension system, absorbing vibration that wouldotherwise pass directly to the user.
- Counterweights oscillate to counteract vibration in tools reducing the vibration, which reaches the operator’s hands.
- Decoupled handles separate the vibrating section of the tool from the user, which also feature a built-in vibration absorber.
Positioning & Vibration
The ergonomic design of a tool, including good grip comfort and pressure, optimal angle of the main handles and a short distance from the main to the support handle, if applicable, is important. As such, power tool ergonomics studies have focused on hand and body positioning.
These two positionings, when designed to fit the task and environment, help reduce exposure of vibration to the hands and potentially the rest of the body. One critical practice is ensuring the tool is held with the minimal amount of force required to keep it safely under control. Power tools designed to allow for a good grip of the tool while in operation can decrease vibration coupling and fatigue, providing a more comfortable operator experience.
Reducing Vibration Exposure
To help your workers reduce the vibrations of their equipment and the transfer of vibrations to their hands and body, employ the following best practices:
- Use high-quality, low-vibration tools.
- Use the right tool for the job.
- Follow manufacturer instructions for use and maintenance.
- Inspect and maintain power tools regularly for wear and damage that could increase vibration exposure. Train workers or individuals responsible for inspecting tools on what to look for. Remove defective or poorly maintained tools from service until they can be repaired or properly disposed of.
- Provide training so workers understand the nature of vibration, how to control or limit exposure, and the signs of fatigue or discomfort.
- Encourage good circulation by keeping hands warm and dry, and exercising fingers during breaks.