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.

Claims

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.

Description

DESCRIPTION OF THE DRAWINGS

[0013] A preferred embodiment of the present invention is described below with reference to the accompanying drawings, in which:

[0014] FIG. 1 is a perspective view of a hydrovac;

[0015] FIG. 2 is driver side view of the hydrovac of FIG. 1;

[0016] FIG. 3 is a passenger side view of the hydrovac of FIG. 1;

[0017] FIG. 4 is a top view of the hydrovac of FIG. 1;

[0018] FIG. 5 is a rear view of the hyrdovac of FIG. 1;

[0019] FIG. 6 is a schematic illustration of an equipment compartment on the driver side of the hydrovac of FIG. 1;

[0020] FIG. 7 is a schematic illustration of a blower behind the equipment compartment in FIG. 6;

[0021] FIG. 8 is a schematic illustration of an equipment compartment on the passenger side of the hydrovac of FIG. 1;

[0022] FIG. 9 is a schematic view of a cab and transmission of a hydrovac;

[0023] FIG. 10 is a schematic view of the transmission and power take-off powering a blower;

[0024] FIG. 11 is an illustration of a boom isolation assembly;

[0025] FIG. 12 is a schematic illustration of a controller for the hydrovac;

[0026] FIG. 13 is a front view of a remote control for operating a hydrovac;

[0027] FIG. 14 is a schematic illustration of a circuit emergency stop buttons are part of; and

[0028] FIG. 15 is a flow chart of a method to initiate an emergency stop of the hydrovac

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0029] FIGS. 1-8 illustrate a hydro-evacuation truck or a hydrovac 10 for performing hydro-excuvations. The hydrovac 10 can include: a frame 20; steering wheels 30; ground wheels 40; a cab 50; an engine 63; a transmission 65; one or more water tanks 60; a debris tank 70; a boom 80; a vacuum hose 90; a blower 100; a controller 200; a water pump 110; a dig wand 120; an emergency shut off valve 170; and, emergency stop buttons 160.

[0030] The frame 20 is supported by the steering wheels 30 and the ground wheels 40. The frame 20 supports the various components of the hydrovac 10. The steering wheels 30 are positioned near the front of the frame 20 and operative to steer the hydrovac 10. The ground wheels 40 are operative to be driven by the engine 63 and move the frame 20 and therefore the hydrovac 10. The drive wheels 40 can be provided on axles.

[0031] The cab 50 can be mounted near a front end of the frame 20. Referring to FIG. 9, the cab 50 can contain a passenger compartment 52 and a hood 54 enclosing the engine (not shown), such as an internal combustion engine. The engine can be connected to the transmission 65.

[0032] The steering wheels 30 can be steered from the passenger compartment 52 of the cab 50 and the transmission 65 can be connected to the axles of the ground drive wheels 40 to drive the ground drive wheels 40 and move the hydrovac 10.

[0033] Referring to FIG. 10, the transmission 65 can also contain power take-offs (PTOs) 57A, 57B. The first PTO 57A can be connected to a first hydraulic pump 58A and the second PTO 57B can be connected to a second hydraulic pump 58B that routes hydraulic fluid through hydraulic lines 59 to a hydraulic motor 102 that powers the blower 100. When the PTOs 57A, 57B are engaged, the speed of the engine 63 will determine how fast the PTOs 57A, 57B turn and therefore the rpms of the hydraulic pumps 58A, 58B. The faster the hydraulic pumps 58A, 58B are rotated, the greater the flow the of hydraulic fluid flowing through the hydraulic fluid lines 59 to the hydraulic motor 102 and the faster the hydraulic motor 102 is driven. The hydraulic motor 102 drives the blower 100, so the faster the hydraulic motor 102 is rotated by the hydraulic fluid, the faster the blower 100 operates.

[0034] Referring again to FIGS. 1-8, the debris tank 70 can be mounted on the frame 20 behind the cab 50 with a rear end of the debris tank 70 positioned proximate a rear end of the hydrovac 10. The debris tank 70 can be used to store the soil and water slurry vacuumed up by the hydrovac 10. The debris tank 70 allows the slurry vacuumed up by the hydrovac 10 to be stored in the hydrovac 10 during its operation and then transported by the hydrovac 10 in the debris tank 70 to a dump site for disposal when the excavation is complete or the debris tank 70 is full. Referring to FIG. 5, the debris tank 70 can have a drain door 72 at the rear end of the debris tank 70 which can be opened to allow the debris tank 70 to be emptied or dumped out.

[0035] Referring again to FIGS. 1-8, the debris tank 70 can be provided with hydraulics so that a front end of the debris tank 70 can be lifted upwards, slanting the debris tank 70 downwards towards its rear end to aid dumping out the debris tank 70.

[0036] The boom 80 can be mounted proximate the rear end of the hydrovac 10 to carry the vacuum hose 90 and to maneuver the vacuum hose 90 to a side of the hydrovac 10 and in some cases even pivot the boom 80 around behind the hydrovac 10. In one aspect, the boom 80 can only maneuver the vacuum hose 90 to one side of the hyrovac 10, such as the passenger side of the hydrovac 10. The boom 80 allows the vacuum hose 90 to be maneuvered into a desired positioned to allow the vacuum hose 90 to suck up soil and any rocks or other debris that have been liquified into a slurry. The boom 80 can be pivotally mounted at a first end 82 so that the boom 80 can be pivoted from side to side around is first end 82 as well as being pivoted upwards and downwards around the first end 82 of the boom 80. A second end 84 of the boom 80 can be curved downwards to direct the vacuum hose 90 downwards towards a ground surface being excavated.

[0037] In one aspect, the boom 80 might have an extendable section 86 that allows the length of the boom 80 to be extendable and retractable to better enable an operator to maneuver the second end 84 of the boom 80 and therefore the vacuum hose 90 to a desired position.

[0038] The vacuum hose 90 can have a distal end 92. With portion of the vacuum hose 90 supported by the boom 80 and running along the boom 80, the distal end 92 of the vacuum hose 90 extends past the second end 84 of the boom 80 so that that the distal end 92 of the vacuum hose 90 can be directed towards the ground surface. An operator can position the distal end 92 of the vacuum hose 90 where they desire by pivoting the boom 80 from side to side and up and down.

[0039] When the hydrovac 10 is not in use or is going to be transported to another location, the boom 80 can be placed in a transport position with the boom 80 swung over top of the hydrovac 10, so that the second end 84 of the boom 80 and the vacuum hose 90 do not extend past the sides of the hydrovac 10. The boom 80 can be pivoted downward to be positioned against a top of the hydrovac 10.

[0040] The vacuum hose 90 can be flexible to allow it to bend so that it can bend as it is maneuvered by the boom 80 and bend downwards around the curved second end 84 of the boom 90 so that the distal end 92 of the vacuum hose 90 points downwards towards a ground surface to be excavated.

[0041] A dig tube (not shown) made of a rigid material, like aluminum, etc. can be attachable to the distal end 92 of the vacuum hose 90. This rigid dig tube can prevent damage and deformation to the vacuum hose 90 because it will be the dig tube that comes directly into contact with the liquified soil and other debris and is vacuumed up the dig tube first before the slurry enters then the vacuum hose 90 connected to the dig tube.

[0042] In one aspect, a portion of the vacuum hose 90 can be flexible while another portion of the vacuum hose 90 might be formed of rigid tubing, made of a rigid material such as metal. For example, a portion of the vacuum hose 90 that extends past the second end 84 of the boom 80 could be flexible tubing, while a portion of the vacuum hose 90 that runs along the boom 80 could be rigid tubing.

[0043] Referring to FIG. 7, the blower 100 can be used to create a vacuum in the debris tank 70. The vacuum hose 90 can be in fluid communication with the debris tank 70 and by creating a vacuum in the debris tank 70 suction will be created in the vacuum hose 90, allowing the vacuum hose 90 to suck a soil and water slurry through the vacuum hose 90 and into the debris tank 70. Referring again to FIG. 10, the blower 100 can be driven by the hydraulic motor 102 that is supplied with hydraulic fluid from hydraulic pumps 58A, 58B which in turn are driven off the first PTO 57A and the second PTO 57B of the transmission 65. The faster the blower 100 is driven, the more vacuum that is created by the blower 100.

[0044] Referring again to FIGS. 1-8, a boom isolation assembly 130 can be provided at the first end 82 of the boom 80 and at a proximal end 94 of the vacuum hose 90 to isolate the vacuum hose 90 from the debris tank 70 and cut off suction created in the vacuum hose 90 from a vacuum in the debris tank 70. Referring to FIG. 11, the boom isolation assembly 130 can have: a chamber 132 with an inlet 134 in the bottom leading to the debris tank 70; a first opening 136 leading to the proximal end 94 of the vacuum hose 90; a second opening 138 on the opposite side of the chamber 132; a plate 140 sized to fit in the first opening 136 and the second opening 138; a rod 142 connected to the plate 140; and an actuator 139, such as a hydraulic cylinder, to move the rod 142 and therefore the plate 140 between the first opening 136, blocking the first opening 136, and the second opening 138, blocking the second opening 138.

[0045] During operation of the hydrovac 10, the boom isolation assembly 130 can be in an open position placing the debris tank 70, and a vacuum created in the debris tank 70, through the inlet 134, in fluid communication with the vacuum hose 90 and creating suction in the vacuum hose 90. The actuator 139 can be retracted, moving the plate 140 into the second opening 138 and placing the vacuum in the debris tank 70 in fluid communication with the vacuum hose 90, creating suction in the vacuum hose 90 and allowing rock, soil slurry and other debris to be sucked through the vacuum hose 90, through the inlet 134 in the chamber 132, and into the debris tank 70. Debris sucked through the vacuum hose 90 will enter the chamber 132 through the first opening 136, some of which can slam into opposite wall of the chamber 132 and the plate 140 positioned in the second opening 138 and fall through the inlet 134, into the debris tank 70.

[0046] Closing the boom isolation assembly 130 can isolate the debris tank 70 from the vacuum hose 90, stopping a vacuum in the debris tank 70 from creating a suction in the vacuum hose 90 and stopping the vacuum hose 90 from sucking debris and other objects into the vacuum hose 90. The actuator 139 can be extended so that the plate 140 is moved from the second opening 138 to the first opening 136, blocking the first opening 136 leading to the distal end 94 of the vacuum hose 90. This will fluidly isolate the vacuum in the debris tank 70 from the vacuum hose 90, stopping suction in the vacuum hose 90.

[0047] FIG. 6 shows the position of the emergency shutoff valve 170 provided in a vacuum conduit 172. The vacuum conduit 172 is in fluid communication with the debris tank 70. The emergency shutoff valve 170 can be a normally open hydraulic valve so that emergency shutoff valve 170 is opened when not supplied with hydraulic fluid. The emergency shutoff valve 170 can have a biasing member, such as a spring, to place the emergency shutoff valve 170 in an open position, venting the vacuum conduit 172 and the debris tank 70 to atmosphere. To create suction, hydraulic fluid can be routed to the emergency shutoff valve 170 to overcome the biasing member and close the emergency shutoff valve 170. When the blower 100 is running, vacuum will be created in the vacuum conduit 172 and thereby suction in the vacuum hose 90 when the emergency shutoff valve 170 is closed.

[0048] When hydraulic fluid flow is stopped to the emergency shutoff valve 170, the biasing member will no longer be acted against by the hydraulic fluid and the biasing member will then force the emergency shutoff valve 170 open, venting the vacuum in the vacuum conduit 172 and the debris tank 70 to atmosphere and reducing or even stopping suction in the vacuum hose 90, even if the blower 100 is still running.

[0049] Referring again to FIGS. 1-8, the water tanks 60 can be provided on the hydrovac 10 to supply water to the water pump 10 where the water will be pressurized and routed to the dig wand 120. The dig wand 120 can be connected to the hydrovac 10 with a hose 122 to provide pressurized water from the water tanks 60 and the water pump 110 to the dig wand 120.

[0050] Referring to FIG. 8, the controller 200 can be used to control various components on the hydrovac 10. In one aspect, the controller 200 can control the operation of the blower 100, the water pump 110, the boom 80, the revolutions per minute (RPM) of the engine 63 and the transmission 65.

[0051] FIG. 12 is a schematic illustration of the controller 200, in one aspect. The controller 200 can include a processing unit 202, such as a microprocessor, that is operatively connected to a computer readable memory 204 and can control the operation of controller 200. Program instructions 206, for controlling the operation of the processing unit 202, can be stored in the memory 204 as well as any additional data needed for the operation of the controller 200.

[0052] A human machine interface 255, such as a touchpad, can be used by a user to interact with the controller 200.

[0053] A control panel 250 can be used to allow an operator to monitor the operation of the controller 200 and control its operation.

[0054] An input interface 220 can be provided operatively connected to the processing unit 202 so that the controller 200 can receive signals from external sensors.

[0055] Referring to FIGS. 1-8 and 12, an output interface 222 can be provided operatively connected to the processing unit 202 to send signals to other components on the hydrovac 10. The output interface 222 can be connected to engine 63 to control various aspects of the operation of the engine 63, such as the RPM of the engine 63, and the transmission 65 to control when the PTOs 57A, 57B are engaged by the transmission 65. By controlling when the PTOs 57A, 57B are engaged by the transmission 65, the controller 200 can control when the blower 100 is operating. The output interface 222 can also be connected to the water pump 110 to control when the water pump 110 is activated.

[0056] The output interface 222 can be connected to the boom 80 to control the operation of the boom 80 as well as the emergency shutoff valve 170, the actuator 139, the water pump 110, the engine 63, and the transmission 65, as well as other components on the hydrovac 10.

[0057] The input interface 320 can be used to receive signals from the various components on the hydrovac 10 to determine the status and operation of these components. The input interface 320 can received signals from the emergency stop buttons 160.

[0058] A wireless interface 224 can be used to allow a remote control to wirelessly connected to the controller 200 and allow the remoted control to control the operation of various components on the hydrovac 10 through the controller 200.

[0059] Referring to FIG. 8, the control panel 250 (and optionally the controller 200) can be located in a storage compartment 260 on a side of the hydrovac 10 for easy access by an operator. The storage compartment 260 can have doors 262 to enclose the control panel 250 when access is not required. The storage compartment 260 can also house the water pump 110 and store a remote control, that controls the operation of the hydrovac 10, when it is not required and, optionally, other components.

[0060] The movement of the boom 80, the operation of the blower 100, creating suction in the vacuum hose 90, and the water pump 110, can be controlled by a remote control that communicates with the controller 200 through the wireless interface 224. FIG. 13 illustrates a remote control 300 that can be used to control the operation of the hydrovac 10 by connecting through the wireless connection 224 of the controller 200 and controlling various components of the hydrovac 10 through the controller 200. In one aspect, the remote control 300 can have: a power on button 301; a boom up button 302; a boom down button 304; a rotate boom counter-clockwise button 306; a rotate boom clockwise button 308; a boom retract button 312; a boom extend button 314; a boom isolation button 316; an eco mode button 318; a water system on/off button 322; a water system pressure increase/decrease button 324; and, an emergency stop button 330. The various buttons can be used to control the operation of the hydrovac 10.

[0061] The remote control 300 may also contain one or more display screens for displaying information about the operation of the hydrovac 10, such as a levels screen 340, showing the level of water in the water tanks 60 and the level of debris in the debris tank 70, and a water system pressure screen 350 showing the pressure of the water in the system pressurized by the water pump 110.

[0062] Referring to FIGS. 1-8, in operation, the hydrovac 10 can be driven to a location where excavation is required. At the location, an operator can park the hydrovac 10 adjacent to where the excavation will occur and exit the hydrovac 10 to begin the hydro-evacuation process. The operator can then move the boom 80 to maneuver the vacuum hose 90 (such as with the remote control 300) over to one side of the hydrovac 10 towards the soil to be excavated and attach a dig tube to the distal end 92 of the vacuum hose 90. The operator can then maneuver the distal end 92 of the vacuum hose 90 and the attached dig tube over the soil to be excavated.

[0063] If the soil to be excavated is not already liquified to create a slurry that can be vacuumed up the vacuum tube 90, the operator can use the dig wand 120 and pressurized water supplied from the water tanks 60 by the water pump 110 to spray the pressurized water into the soil to liquify the soil and create a vacuumable slurry.

[0064] The operator can then start the blower 100 to create a vacuum in the vacuum hose 90 and direct the distal end 92 of the vacuum hose 90 towards the liquified soil to vacuum the soil slurry up through the vacuum hose 90 and into the debris tank 70.

[0065] When the excavation is complete or the debris tank 70 is full, the operator can stop spraying water with the dig wand 120 and stop the blower 100 from creating a vacuum in the vacuum hose 90. They can then disconnect the dig tube 95 from the distal end 92 of the vacuum hose 90 and maneuver the boom 80 to position the boom 80 and the vacuum hose 90 back over the hydrovac 10 and place it in a transport position. With everything stowed away on the hydrovac 10, the hydrovac 10 can be driven to a dump site and the debris tank 70 emptied.

[0066] If the debris tank 70 has hydraulics, the debris tank 70 the drain door 72 can be opened and the debris tank 70 tilted to dump out the contents of the debris tank 70 at the dump site.

[0067] However, certain situations can occur during the operation of the hydrovac 10 where it is desired to shut down the hydrovac 10 for safety. For example, this could occur when rock or other debris are stuck to the end of the dig tube or stuck in the vacuum hose 90 and its need to release vacuum pressure. It could also occur when the operator gets a foot or other body part stuck in the dig tube and the system needs to be shut down to prevent or lessen injury, the remote control 300 could also get sucked into the system through the vacuum hose 90, or for any number of other reasons.

[0068] Rather than providing an instantaneous shut down/stop of various systems on the hydrovac 10, which could damage the components or increase wear decreasing their service life, various components on they hydrovac 10 can be de-energized/deactivated after an emergency stop button 160 on the hydrovac 10 is pressed to protect the operator and/or the surroundings, eventually placing the hydrovac 10 in a zero-energy state.

[0069] Referring to FIGS. 2 and 5, emergency stop buttons 160 can be provided at one or more locations on the hydrovac 10. Typically, these will be positioned where they are easily accessible by an operator of the hydrovac 10 as they are using the hydrovac 10 to perform hydro-evacuation of soil. In FIG. 2, the emergency stop button 160 is shown on the driver side of the hydrovac 10 and in FIG. 5, the emergency stop button 160 is shown on the back of the hydrovac 10, but they could be located anywhere they are reachable by an operator and may be desirable to place.

[0070] The emergency stop buttons 160 can be connected to the input interface 220 of the controller 200 so that the controller 200 can receive a signal when one of the emergency stop buttons 160 is pressed. Referring to FIG. 14, the emergency stop buttons 160 can also be connected to a relay 400 between the output interface 222 and a power supply 410, supplying power to the output interface 222. The relay 400 can interrupt the supply of power form the power supply 410, stopping the output interface 222 from supplying power to hydraulic solenoid valves 420 controlling the flow of hydraulic fluid on the hyrdrovac 10. In one aspect, the hydraulic solenoid valves 420 can control the flow of hydraulic fluid to the emergency shut off valve 160, the blower 100, the boom 80 and/or the water pump 110.

[0071] The hydraulic solenoid valves 420 can be normally in the closed position when a voltage is not being supplied to the solenoid valves. The hydraulic solenoid valves 420 typically have a biasing element, such as a spring, to keep the hydraulic solenoid valves 420 in the closed position when no voltage is being supplied to the hydraulic solenoid valve 420. However, when voltage is supplied to any of the hydraulic solenoid valves 420, from the output interface 222, the force of the biasing element is overcome and the hydraulic solenoid valve 420 can open.

[0072] When one of the emergency stop buttons 160 is pressed, the relay 400 is opened and the power supply to the output interface 22 is interrupted. Any power being supplied to the hydraulic solenoids 420 is also interrupted. This interruption in the voltage supplied from the output interface 222 of the controller 200 will stop voltage being supplied to these hydraulic solenoid valves 420, causing the force overcoming the biasing elements in these hydraulic solenoid valves 420 to once again close the hydraulic solenoid valves 420, stopping the flow of hydraulic fluid through the hydraulic solenoid valves 420 and therefore the supply of hydraulic fluid to various components being driven by the hydraulic flows.

[0073] Referring to FIG. 15, a flow chart of a method for conducting an emergency stop the hydrovac 10 is provided. The method can start when an operator or some other person presses one of the emergency stop buttons 160 on the hydrovac 10. With the emergency stop button 160 pressed, the method can begin and at step 502 and interrupt the voltage to the hydraulic solenoid valves 420 with the relay 400. This can physically break the electrical connection between the controller 200 and the hydraulic solenoid valve 420 that directs hydraulic fluid to the emergency shutoff valve 170. This interruption of voltage will cause the biasing element in the hydraulic solenoid valve 420 to stop the flow of hydraulic fluid to the emergency shutoff valve 170. This stopping of the hydraulic fluid flow, will remove the force on the emergency shutoff valve 170 that is overcoming the biasing member, such as a spring, and keeping the emergency shut-off valve 170 closed. Without this force, the biasing member will force the emergency shutoff valve 170 open, placing the debris tank 70 in fluid communication with the atmosphere and allowing the debris tank 70 to be vented to the atmosphere. This will decrease the vacuum in the debris tank 70 and thereby decrease the suction in the vacuum hose 90.

[0074] Additionally, the emergency stop buttons 160 can physically break the connection between the controller 200 and other hydraulic solenoid valves 420 that directs flow to all other hydraulic functions. This interruption of control will cause the biasing element in the hydraulic solenoid valve 420 to stop the flow of hydraulic fluid to all functions preventing them from operating. This will stop the blower 100, the water pump 110 supplying pressure to the wash system, and the movements of the boom 80.

[0075] Optionally, at step 504 the controller 200 can stop supplying voltage through the output interface 220 to the hydraulic solenoid valves as a redundancy to physically interrupting the connection between the output interface 220 and the and the hydraulic solenoid valves 420. Because the emergency stop button 160 can be connected to the input interface 220 of the controller, when the emergency stop button 160 is pressed a signal can also be received by the controller 200. In the event that the pressing of the emergency stop button 160 does not physically interrupt the voltage to the hydraulic solenoid valves 420, the controller 200 can also stop sending voltage, causing any hydraulic solenoid valves 420 to close, and stopping the flow of hydraulic fluid to the components, stopping the operation of these components.

[0076] At step 506, the engine 63 of the hydrovac 10 can be reduced to an idle rpm. The proceeding unit 202 can send a signal through the output interface 222 to reduce the engine 63 to an idle rpm. By reducing the rpm of the engine 63 to an idle rpm, the rotational speed of the PTOs 57A, 57B of the transmission 65 connected to the engine 63. The hydraulic pumps 58A, 58B, which are driven by the PTOs 57A, 57B will also decrease their rotation.

[0077] At step 508, when the engine 63 has been reduced to idle, the PTOs 57A, 57B can be disengaged. The controller 200 can send a signal through the output interface 222 to the transmission 65 to disengage the PTOs 57A, 57B. By disengaging the PTOs 57A, 57B, rotation of the hydraulic pumps 58A, 58B connected to the PTOs 57A, 57B will be reduced, thereby depressurizing the hydraulic fluid in the system.

[0078] The hydrovac 10 can remain in the zero-state energy state with the hydrovac 10 engine 63 running but its system shut down until an operator manually resets the system. If the emergency stop button 160 are the type that stay depressed once pushed, the operator can pull the emergency stop button 160 back to its up position, acknowledging the e-stop message at the control panel 350 and begin the system start-up sequence.

[0079] The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.