Machine Guards: A Life Saver
Recently I watched The Terminator, the classic Arnold Schwarzenegger movie. In the film, machines come to life in the year 2029 for the sole purpose of maiming and destroying the entire human race.
The movie ends with heroine Sara Connor crawling through a hydraulic press to escape from the Terminator who is in close pursuit. When Connor reaches the end of the press, she closes the gate guard to prevent the Terminator from harming her. She later activates the press and terminates the Terminator.
In reality, we all know machines cannot and will not come to life, even though some operators think machines have a mind of their own. Despite this fact, however, machines can still maim and kill. But a machine-inflicted injury and even death can be prevented with the proper installation and use of machine guards.
The purpose of machine guards is to protect the machine operator and other exposed employees from hazards, such as those created by point of operation, ingoing nip points and rotating parts. There are many types of machine guarding methods, including fixed guards, interlocking guards, adjustable guards, self adjusting guards and barrier guards.
- Fixed guards are a permanent part of the machine. They are independent from moving parts in order to protect from injury. Most often these guards are made of sheet metal, screen, wire cloth, bars, plastic or any material strong enough to withstand a strong impact.
- Interlocking guards are connected to a tripping mechanism that automatically shuts off the machine's power when the guard is opened or moved. These guards are effective with electrical, mechanical, hydraulic or pneumatic systems and are often used on a combination of these systems.
- Adjustable guards are commonly used on machines where cutting, pressing or shearing of various size stock is needed. These guards are often times manually adjusted and can be found on various kinds of saws, including band saws and table saws
- Self-adjusting guards automatically adjust to the thickness of the stock. An example of this is a guard on a table saw, where the guard's opening is determined by the movement of the stock being pushed through.
- Guard barriers, such as post and chains or a standard guardrail system with a top-rail and a mid-rail, can also be used provided they are maintained at a distance to prevent employees from accidentally coming in contact with moving parts.
Keep in mind that no matter what type of machine guard is used, effective and good ones have certain characteristics. First, the guard must be designed so it cannot be easily removed or knocked off. An operator will oftentimes remove a guard if it gets in the way when performing tasks, or leave a guard off when it falls from the machine, whereby exposing the machine's moving parts. Secondly, guards should prevent body part entry. And lastly, guards must not interfere with the normal operation of the machine. If these characteristics are considered when selecting a guard, then an operator would be less inclined to remove the guard either temporarily or permanently.
Lastly, there should be at least one or more machine guarding methods to protect an operator and other employees who are exposed to a machine and its moving parts. If you are unsure whether a machine guard is needed or not, then take the safe route and provide a guard. You can contact the machine manufacturer about providing or replacing a guard. If the manufacturer does not offer guards, consider efforts to fabricate a guard such as a fixed or interlocking guard or a guard barrier.
Even though machines do not have a mind of their own, you must guard against their ability to maim or destroy one of your employees. "If it moves, guard it" is a helpful phrase is I learned while attending an OSHA Training Institute machine guarding class. Make it a point to install, inspect or replace your machine guards today. Machine guards can and will save lives.