Time delay for a seat switch activated loader boom lock

Claim 1

In a loader having a mobile frame including upwardly extending, laterally spaced side members; a boom structure pivotally mounted on said frame and moveable in a generally vertical path direction, said boom structure including a pair of boom arms generally vertically moveable along a path adjacent said sidewalls; first power means operatively associated with said boom structure for moving said arms along said path of movement; and an operator's compartment positioned between said sidewalls, the improvement comprising: power interruption means operatively associated with said power means to selectively render said power means inoperative to vertically move said boom structure; control means operatively connected to said power interruption means for selectively controlling the operation thereof to render said power means inoperative to vertically move said boom structure, said control means including an electrical circuit having a first switch manually moveable between an on position and an off position and a second switch operatively positioned to sense the presence of an operator within said operator's compartment, said second switch being positioned in an on position when an operator is sensed within said operator's compartment and in an off position when an operator is not sensed within said operator's compartment, said electrical circuit being connected to an energy source to provide energy to control said power interruption means, said power interruption means rendering said power means inoperative when either of said first and second switches are positioned in the off position; and time delay means operatively associated with said control means to prevent said power interruption means from rendering said power means inoperative for a predetermined period of time after said second switch becomes positioned in said off position, said time delay means including a capacitor connected to said electrical circuit in parallel with said energy source, a first diode connected to said electrical circuit in series with said capacitor and in parallel with a resistor, said capacitor providing a temporary source of electrical current to said power interruption means after said second switch has been moved to said off position, said first diode permitting the flow of current from said energy source to charge said capacitor and requiring the flow of current from said capacitor to flow to said power interruption means through said resistor.