Single switch PTO enabler

Claim 1

In an internal combustion engine comprising an electronic engine control for controlling various operational functions of the engine wherein one operational function requires a momentary switch function and comprises momentary switch means for performing that one operational function, the improvement in said momentary switch means which comprises: A) a main electronic switch having a principal conduction path and a control input for rendering said principal conduction path selectively operable to a first conductivity condition and to a second conductivity condition different from such first conductivity condition for enabling said main electronic switch to provide such momentary switch function; B) a control request switch that is selectively operable to first and second switch conditions, and when operated from such first switch condition to such second switch condition, is effective to cause said principal conduction path of said main electronic switch to momentarily operate from one of its two different conductivity conditions to the other of its two different conductivity conditions and thereby perform such momentary switch function while said control request switch is maintained in such second switch condition; and C) an electronic timing circuit for operatively coupling said control request switch with said main electronic switch, said electronic timing circuit comprising, 1) a series RC circuit across which said control request switch is effective to connect a DC voltage when said control request switch is operated to its second switch condition, said series RC circuit executing an electrical transient when such DC voltage is so connected and comprising timing capacitor means that is charged during such transient; 2) a further electronic switch having a principal conduction path and a control input for rendering its principal conduction path selectively operable to two different conductivity conditions, 3) means electrically associating said control request switch, said further electronic switch and said series RC circuit comprising a) means connecting said control input of said further electronic switch with a portion of said series RC circuit for causing the electrical transient to be applied to said control input of said further electronic switch and cause said principal conduction path of said further electronic switch to execute a single cycle of momentarily switching from one of its two different conductivity conditions to the other during a portion of such electrical transient and at the conclusion of such portion of such electrical transient returning to such one conductivity condition and remaining in such one conductivity, condition irrespective of the amount of time for which said control request switch remains in its second switch condition, and b) means for discharging said timing capacitor means when said control request switch is returned from its second switch condition to its first switch condition; and 4) resistor means operatively connecting said principal conduction path of said further electronic switch with said control input of said main electronic switch for causing said principal conduction path of said main electronic switch to also execute a single cycle of momentarily operating from its first conductivity condition to its second conductivity condition during such portion of such electrical transient and at the conclusion of such portion of such electrical transient returning to its first conductivity condition and remaining in such first conductivity condition as long as said further electronic switch remains in its one conductivity condition.