06.06.2016

Dual secondary guarding systems for scissors

Italian aerial lift manufacturer Airo and its UK distributor Aerial and Handling have developed a new dual secondary guarding system for scissor lifts

The two companies have studied the number and type of entrapment injuries and concluded that the majority of injuries do not result from upward/overhead impact, but from shear type impacts, caused when the operator was looking at the ground - rather than straight ahead - while driving. These type of injuries tend to result in a far more serious injuries.

As a result the two decided that any new system should provide preventative and physical protection and allow the operator to be involved in setting the system. And wanted it to be telematics compatible. The new system dubbed S.A.F.E (Self-Adjustment From Entrapment) includes an electronic cut out and physical barrier which can be used in conjunction with each other or individually, depending on the job and associated risks.

The electronic part is activated by the operator raising the platform to the ceiling or lowest obstacle height, holding a button on the console down for three seconds until the setting is confirmed by LED lights and a multi-tone alarm. The scissor lift will now only lift to that height until it is re-set as required. This takes care of upward movement crushing - as long as the machine is not moved to an area with lower obstacles without resetting.
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The SAFE electronic control panel

The two then decided that a physical crash-bar type structure was needed to minimise the shear injuries caused when travelling. This has been achieved with a fold-away safety frame, based on the company’s Sanctuary Zone system for boom lifts. Ideally it should be extended before moving the lift, and can be quickly folded into the stowed position alongside the guardrails when working .
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The scissor with the modified Safety Zone erected for travelling

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The Safety Zone protection in the folded position

Ian Harding of AHS said: “When the platform extension is fully extended it is very easy to demonstrate why injuries can occur. On some scissor lifts the deck extension can extend 1.5 metres or more, meaning the steering wheels are almost the same distance behind you and possibly more than 16 metres or more below. If the steering wheels have been left on full lock at 90 degrees to the chassis and you simply grab the joystick and move it fully in either direction - even at the low elevated drive speed - your first movement is sideways - up to 300mm. That is a serious unplanned change of direction.”
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Airo and AHS believe that the majority of entrapment injuries in scissor lifts are caused by shear type impacts

“We also wanted to conceive a design that can be enhanced as awareness and acceptance for new technologies - especially telematics – increases. We have collaborated to produce what we think is a genuinely usable and practical system for secondary guarding on scissor lifts.”