By OH&S laws, Very Narrow Aisle (VNA) materials handling equipment operating in a narrow aisle, must be guided mechanically. There are two choices of guidance, wire or rail, but how do they work?
Wire guidance involves cutting a 10-12mm deep x 3mm wide path in the concrete slab, inserting an electrical wire to form a loop/circuit, sealing over the laid wire & then connecting the wire ends to a line driver which is generally supplied with the VNA equipment.
What Is Wire Guidance?
Wire guidance involves cutting a 10-12mm deep x 3mm wide path in the concrete slab, inserting an electrical wire to form a loop/circuit, sealing over the laid wire & then connecting the wire ends to a line driver which is generally supplied with the VNA equipment. The line driver is basically a transformer that creates an electrical circuit of up to 1500 meters per loop through the laid wire. The VNA equipment is fitted with sensors underneath the equipment that pick up the signal being giving off by the wire & ensure the unit follows that signal.
Rail guidance is laying 100mm(h) x 75mm(w) x 10mm(t) hot rolled steel lengths on each side of the aisle. These steel lengths are secured using chemical anchors at 300mm spacing’s for the first 3 meters & then 800mm spacing’s for the remainder of the aisle until you reach the final 3 meters where you revert back to 300mm spacing’s. The VNA equipment is fitted with one set of guide wheels at the front & another set of guide wheels at the back. Generally these wheels are spring loaded & have a pressure switch fitted behind them. When the pressure switch is depressed too far, it tells the unit to steer slightly in the opposite direction, so the unit basically travels in a mild pinball type motion down the aisle. |