Leaf Switches

Leaf switches are in most of the older models of juke box.

They are designed to be accessible for cleaning and maintenance.

Basically consisting of thin strips of sprung copper with a contact fixed to one end and held at the other in strips of insulated material. The switches can be built up in to many different configurations to provide multiple switching actions such as the Seeburg reversing switch shown below -

Many of this type are actuated by a lever/spring arrangement with the different sections of switches movement coordinated by the end plate.This will ensure all switch sections change simultaneously.

This type of switch was used by not only Seeburg but Wurlitzer, AMi and RockOla and it is not unknown for the switches of this type to loose their spring device that snaps the end plate over thus loosing the switching action and even that end plate to be missing.Cleaning contacts is another of the restorers "mysteries" - or rather - how to do it properly is. "Flooding" the contacts with switch cleaner isn't really going to help on old tarnished contacts. Switch cleaner will loosen the dirt and if you use too much will also swill some of it out !  However this is NOT the most effective way that it can be done . Certainly use switch cleaner to loosen the dirt, preferably a type of switch cleaner that evaporates and does NOT leave a deposit. Then using  a rough piece of thickish paper pass it between the contacts that are closed - simple as that. Heavier deposits can be removed with the aid of the contact cleaning "pen" that I sell with the stiff fibre glass tips -very effective. You can buy contact burnishers, which if you get the correct grade, are also very effective. DO NOT use course emery paper, sand paper, Files or Wire Wool -- if you do then a nasty disaster could be waiting just for the switch you use it on. When cleaning the contacts you should aim not to scratch or rough them up as this uneven surface can promote electrical arcing.

Adjustment of these types of switches is often bodged.

Lets look at a typical type:

You can see from this very simplified diagram that  there is a central moving leaf which has a leaf contact to the left and to the right. The central leaf has two contacts so that it can make to the contacts on the left or right leaf whichever way it is moved. With extended use the leaves start to lose some of their tension, the contacts wear down slightly and so the contact force becomes less and less : result in switching failure.

Cleaning the contacts will not help this problem. Obviously the contacts need to meet with more force to ensure a positive switch action.

How is this often achieved : people BEND IT and that is wrong ! So  how do you do it ?

Do NOT bend the leaves of the switch as you will then make the contacts touch at an angle instead of square on. This can also give a poor switching action and will lead to uneven wear of the contact, thus creating the problem again, but this time the contact will need to be changed.

It is simple all you have to do is move the short 'tension'  strips at the side of the contacts either towards or away  from them. That is their purpose and usually that is all that is required to alter gaps/pressures. Check it out when you next have to fiddle around with this type of switch.