Hydrovac with emergency stop

Abstract

A hydrovac and a method of conducting an emergency is provided. The hydrovac has an engine, a transmission, steering wheels, ground wheels, a debris tank, a vacuum hose connected to the debris tank, a boom carrying the vacuum hose, a blower operative to create a vacuum in the debris tank, a hydraulic fluid pump, an emergency shutoff valve connected in fluid communication with the debris tank, at least a solenoid valve connected between the hydraulic fluid pump and the emergency shutoff valve, a relay connected between a voltage source and the hydraulic solenoid valve, and an emergency stop buttons operative to interrupt voltage when the emergency stop buttons is pressed. Pressing the at least one emergency stop button interrupts voltage to the at least one hydraulic solenoid valve, stopping supply of hydraulic fluid to the emergency shutoff valve, opening the emergency shutoff valve and venting the debris tank.

1 . A hydrovac comprising:
 a frame;   a cab mounted near a front end of the frame;   an engine;   a transmission connected to the engine;   steering wheels operative to steer the hydrovac;   ground wheels connected to the frame and operative to be driven by the engine through the transmission;   a debris tank;   a vacuum hose fluidly connected to the debris tank, the vacuum hose having a distal end;   a boom pivotally mounted at a first end and carrying the vacuum hose;   a blower operatively connected to the debris tank and operative to create a vacuum in the debris tank;   a hydraulic fluid pump;   an emergency shutoff valve connected in fluid communication with the debris tank, the emergency shutoff valve being a normally open hydraulic valve and supplied with hydraulic fluid by the hydraulic fluid pump;   at least one hydraulic solenoid valve connected between the hydraulic fluid pump and the emergency shutoff valve to control the flow of hydraulic fluid to the emergency shutoff valve, the at least one hydraulic solenoid valve being a normally closed hydraulic solenoid valve;   a relay connected between a voltage source and the at least one hydraulic solenoid valve; and   at least one emergency stop buttons provided on the hydrovac operably connected to the relay, the relay operative to interrupt voltage when the at least one emergency stop buttons is pressed,   whereby pressing the at least one emergency stop button interrupts voltage to the at least one hydraulic solenoid valve, stopping supply of hydraulic fluid to the emergency shutoff valve, opening the emergency shutoff valve and venting the debris tank.   
     
     
         2 . The hydrovac of  claim 1  wherein the transmission further comprises at least one power take-off (PTO), the at least one power take-off connected to at least one hydraulic pump, and wherein the at least one hydraulic pump is connected to a hydraulic motor driving the blower. 
     
     
         3 . The hydrovac of  claim 2  wherein the transmission comprises: a first power take-off connected to a first hydraulic; and a second power take-off connected to a second hydraulic pump, and wherein the first hydraulic pump and the second hydraulic pump are connected to the hydraulic motor. 
     
     
         4 . The hydrovac of  claim 2  further comprising a controller connected to the at least one emergency stop button and operative to reduce a speed of the engine to an idle revolutions per minute (rpm) when the at least one emergency stop button is pressed. 
     
     
         5 . The hydrovac of  claim 4  wherein the controller is further operative to disengage the at least one PTO when a speed of the engine is reduced to the idle rpm. 
     
     
         6 . The hydrovac of  claim 2  wherein the relay is connected between an output interface of the controller and a power supply to the output interface, the controller operative to stop supplying voltage to the hydraulic solenoid valve when the at least one emergency stop button is pressed. 
     
     
         7 . The hydrovac of  claim 1  wherein one of the at least one hydraulic solenoid valve is connected between the hydraulic fluid pump and the blower. 
     
     
         8 . The hydrovac of  claim 1  wherein one of the at least one hydraulic solenoid valve is connected between the hydraulic fluid pump and the boom. 
     
     
         9 . The hydrovac of  claim 1  further comprising a water pump operatively connected to a water tank on the hydrovac and wherein one of the at least one hydraulic solenoid valve is connected between the hydraulic fluid pump and the water pump. 
     
     
         10 . The hydrovac of  claim 1  wherein the emergency shutoff valve is positioned in a vacuum conduit in fluid communication with the debris tank. 
     
     
         11 . The hydrovac of  claim 1  wherein an emergency stop button is positioned on a driver side of the hydrovac. 
     
     
         12 . The hydrovac of  claim 1  wherein an emergency stop button is positioned on a back of the hydrovac. 
     
     
         13 . The hydrovac of  claim 1  wherein the debris tank is provided behind the cab and proximate a rear end of the hydrovac 
     
     
         14 . A method of conducting an emergency stop of a hydrovac comprising:
 providing a hydrovac comprising: a debris tank; a vacuum hose fluidly connected to the debris tank; a blower operatively connected to the debris tank and operative to create a vacuum in the debris tank; an emergency shutoff valve connected in fluid communication with the debris tank, the emergency shutoff valve being a normally open hydraulic valve and supplied with hydraulic fluid by the hydraulic fluid pump; and at least one hydraulic solenoid valve connected between the hydraulic fluid pump and the emergency shutoff valve to control the flow of hydraulic fluid to the emergency shutoff valve; and   in response to pressing an emergency stop button on the hydrovac, interrupting a supply of voltage to the at least one hydraulic solenoid, stopping hydraulic fluid to the emergency shutoff valve to open the emergency shutoff valve, venting the debris tank.   
     
     
         15 . The method of  claim 14  further comprising using a controller to stop supplying voltage to the hydraulic solenoid valve. 
     
     
         16 . The method of  claim 14  further comprising stopping a flow of hydraulic fluid to the blower. 
     
     
         17 . The method of  claim 14  wherein the hydrovac further comprises: a frame; a cab; an engine; and a transmission connected to the engine and having a power take-off (PTO), the PTO connected to a hydraulic fluid pump. 
     
     
         18 . The method of  claim 17  further comprising in response to pressing the emergency stop button, reducing a speed of the engine to an idle revolutions per minute (rpm). 
     
     
         19 . The method of  claim 18  further comprising when the engine speed is reduced to the idle rpm, disengaging the PTO.