receive and hold in a fixed position a switch 80 the switch 80 comprises a switch housing 82 and an element 84 the element 84 is comprised of a resilient material which can be moved so that its end 86 is either away from the switch housing 82 or in contact therewith when the end 86 contacts the switch housing 82 the circuit is closed and electrical signals can be transmitted along wires 88 to a source component the source component is not shown in fig2 to 5 but may be any one of a number of devices for example as discussed with respect to fig1 and 2 the switch 80 is located within an insulator 90 the insulator 90 comprising a u shaped bracket for receiving the switch 80 both the switch 80 and insulator 90 have a pair of holes 92 and 94 through which screws 96 may pass the upper internal bracket 56 has a pair of tapped holes 98 which are arranged with respect to each other such that the screws 96 pass through the insulator 90 switch 80 and are fixed to the upper surface of the internal bracket 56 the latch retractor 54 has a pin hole 100 for receiving a pin 102 the pin hole 100 is angled with respect to the horizontal as best illustrated in fig9 in one preferred form the pin hole 100 has an axis which is approximately at 60.