Abstract: An interactive advertising display that has a display element, a transmitter operative to output a wireless signal in response to movement, and a receiver for receiving the signal from the transmitter. The receiver is connected to the display element so as to turn the display on and off in response to the signal from the transmitter.

Abstract: A method of making an anchor bolt with a thread on a section thereof comprising the steps of providing a metal bar (1) of circular or near circular cross-section having a diameter which is substantially equal to the pitch diameter of the thread to be provided thereon, extruding the bar along a selected section (A) thereof to reduce its cross-section, forming a series of lateral protrusions (3) on the selected section of the bar, straightening the bar, and, forming a thread (5) with the said pitch diameter on a further selected section of the bar.

Abstract: A method of making a rock bolt (1) with a thread on a section thereof comprising the steps of; providing a metal bar of circular or near circular cross-section having a diameter which is substantially equal to the pitch diameter of the thread to be provided thereon; passing the bar in a single pass between a pair of rolls (8, 9) to pinch the bar at intervals to cold form protrusions (2) spaced from one another in staggered formation on opposite sides of the bar along a selected section thereof; displacing one or more of said rolls (8, 9) away from the other at a selected time to ensure that said protrusions are formed only on said selected section of bar; straightening the bar in its cold condition; and cold rolling in a thread (4) with said pitch diameter on a further selected section of the bar which is free of the said protrusions.