Water spray control system for underground mining machine

A fire suppression water spray array for an underground mining machine includes an accumulator, and a normally open electrically operated valve interconnected in the machine hydraulic control system for operating a hydraulically operated water spray control valve to initiate the water spray in the event of interruption of electrical power to the machine.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention pertains to an automatic water spray control system 
for fire suppression in the vicinity of underground coal mining machinery 
and the like. 
2. Background 
Underground coal mining machines, such as so-called continuous mining-type 
machines, are typically equipped with an arrangement of water spray 
nozzles connected to a source of high-pressure water for control of dust 
and for fire suppression in the event of ignition or eruption of fire in 
the vicinity of the machine. Underground mining machines, typically, also 
use electricity as a primary source of power and have hydraulic systems 
for operating various machine functions and for controlling a dust 
suppression water spray nozzle array and a fire suppression water spray 
nozzle array. 
One shortcoming of conventional systems is that, in the event of a failure 
of the electrical power supply system to the mining machine, hydraulically 
operated control valves will not function to initiate operation of the 
fire suppression water sprays, in particular. Moreover, if the mining 
machine is located in an area of the mine which is beyond safe limits of 
operator access, the machine cannot be reached for manual operation of the 
water sprays. In this regard, the present invention provides an improved 
water spray control system which is adapted to operate fire suppression 
water sprays, in particular, in the event of a failure or shutoff of the 
electrical power system which would normally also cause a failure or 
shutdown of a hydraulic fluid power and control system. 
SUMMARY OF THE INVENTION 
The present invention provides an improved control system for controlling 
the initiation of water sprays for suppressing or minimizing the chance of 
fire on or in the vicinity of an underground mining machine. In accordance 
with one aspect of the present invention, a control circuit is provided 
for operating a water spray control valve which is hydraulically actuated 
and which will effect initiation of water sprays in the event of failure 
or shutoff of an electrical power supply to or on the mining machine. 
In accordance with another important aspect of the present invention, a 
water spray control system is provided which is particularly adapted for 
underground mining machines, wherein a hydraulically operated water spray 
shut-off valve may be actuated by a source of hydraulic fluid including an 
accumulator and a normally open electrically-operated valve which will 
provide a supply of hydraulic fluid to the water spray control valve in 
the event of electrical power interruption to the mining machine. 
Accordingly, in the event of failure of the machine hydraulic system due 
to electrical power interruption or other systemic failures, a sufficient 
supply of fluid is provided by the present invention to operate a fire 
suppression water spray control valve to initiate the flow of water to the 
spray nozzle array. 
Those skilled in the art will recognize the above-described advantages and 
features of the present invention as well as other superior aspects 
thereof upon reading the detailed description which follows in conjunction 
with the drawing.

DESCRIPTION OF A PREFERRED EMBODIMENT 
In the description which follows, like parts are marked throughout the 
specification and drawing with the same reference numerals, respectively. 
The drawing figures are not to scale and a substantial number of 
components are illustrated in schematic form utilizing standard symbols. 
Referring to FIG. 1 there is illustrated in plan view an "outline" of an 
underground, so-called continuous-type mining machine, generally 
designated by the numeral 10. The mining machine 10 may be one of several 
configurations but for illustrative purposes includes a frame 12, on which 
are mounted spaced apart rotary cutter heads 14 which operate to cut into 
a coal seam and to convey the cut coal pieces onto a conveyor 16 for 
movement of the produced coal away from the machine in the direction 
indicated by the arrow 18. The mining machine 10 may take on various forms 
and the particular machine illustrated and described is for illustrative 
purposes only. Suffice it to say that machines of the type represented by 
the machine 10 are operated in underground mines to cut into coal seams 
and are typically remotely controlled so that the machine operator may 
stand a relatively safe distance from the machine during its operation. 
The machine 10 is also supplied with fire and dust suppression control 
water from a supply hose 20 which is connected to a bank of control 
valves, represented in FIG. 1 as being disposed in an enclosure 22, or 
otherwise grouped closely on the machine. In like manner, electrical 
controls, including a radio receiver, are typically mounted on the machine 
frame 12 within an enclosure or envelope 24 to which is connected an 
electrical cable 26 for supplying electric power to the machine 10. A 
remote radio transmitter type controller apparatus 28 is adapted to 
control the machine operation, including control of water sprays, 
operation of the cutter heads, and other functions. The controller 28 may 
also be operated to remotely shut off electrical power to the machine 
operating controls and devices. The controller 28 may also be connected to 
the machine by an elongated control cable, not shown, instead of utilizing 
radio control signals. 
The mining machine 10 is provided with an array of water spray nozzles 
including sets of nozzles 32, 34, 36, and 38 which are connected to water 
supply conduits 40 and 42, including a crossover conduit 41. The supply 
conduit 40 is also connected to the enclosure or control valve bank 22 
which will be disclosed in further detail herein. The conduit 42 is 
connected to the main water supply 20 and includes a manually actuated 
valve 44 interposed therein for manually controlling the operation of the 
spray nozzle arrays 32, 34, 36, and 38 from one side of the machine 10. As 
will be described in further detail herein, a second manually operated 
valve for the fire suppression water spray nozzle array is located in the 
vicinity of the enclosure 22 for manually initiating the water spray from 
the side of the machine opposite the side at which the valve 44 is 
located. 
Referring now to FIG. 2, the control system for the machine 10 typically 
includes a hydraulic fluid pump 50 driven by an electric motor or the like 
52. The pump 50 supplies hydraulic fluid by way of a conduit 54 to a valve 
manifold 56 which supplies hydraulic fluid to pressure regulator valves 58 
and 60. The pressure regulator valve 60 supplies pressure fluid to 
solenoid operated valves 62 and 64 and to a conduit 66. The conduit 66 is 
in communication with a check valve 68, an accumulator 70, and a solenoid 
operated, normally open valve 72. The valve 72 is operable to supply 
hydraulic fluid to a pilot operated control valve 74 which is interposed 
in a conduit connected to the main water supply conduit 20 for supplying 
water to the spray nozzles 32, 34, 36, and 38 by way of the conduit 40, as 
illustrated. 
The enclosure 22 includes pilot pressure fluid operated control valves 76 
and 78 which are operable to be opened by pilot pressure fluid from the 
valves 64 and 62, respectively, when the valves 64 and 62 are electrically 
energized by suitable remote controls such as on the controller 28. The 
enclosure 22 still further includes manually operated values 80 and 82 
which are in communication with the main water supply conduit 20 so that 
water may be conducted to the fire suppression spray array by way of the 
conduit 40 and to a dust suppression water spray array, not shown, by way 
of a conduit 84. Hydraulic fluid is also supplied by the pump 50 to a 
control valve bank generally designated by the numeral 86 for operating 
certain control valves to control some of the primary functions of the 
machine 10 which will not be discussed in further detail herein. 
Accordingly, in the normal operation of the machine 10, hydraulic fluid is 
supplied by the pump 50 to the pilot fluid control valves 62 and 64 and 
these valves may be operated by remote control to open the valves 78 and 
76, respectively, to supply water to the fire suppression water spray 
array and to the aforementioned dust suppression water spray array by way 
of the conduits 40 and 84, respectively. Still further, the fire 
suppression water spray array may be furnished with water by way of the 
conduit 20 and the manually operated valves 44 and 80. As indicated by the 
diagram of FIG. 2, the manually operated valve 82 may also be actuated to 
supply water from the conduit 20 to the conduit 84 leading to the dust 
suppression spray array, not shown. Accordingly, if operating personnel 
are adjacent the machine 10, on either side thereof, the valves 44 and 80 
are usually easily accessible for turning on the fire suppression water 
spray array. Still further, if an operator is in the vicinity of the valve 
48, FIG. 1, the fire suppression water spray array may also be remotely 
turned on and off. 
As previously mentioned the machine operator may remotely control the 
valves 64 and 62, provided electrical power is available, to open the 
valves 76 and 78. However, if electrical power should fail or be purposely 
shut off in an emergency, or the cable 26 cut thereby preventing control 
of the machine 10, the fire suppression water spray arrays will be 
operated thanks to the provision of the valve 72 and the accumulator 70 
which supply pressure fluid by way of conduit 73 to the pilot operated 
control valve 74. For example, if electrical power to the machine 10 
should be interrupted, the valve 72 will move to the open position a 
discharging hydraulic fluid from the accumulator 70 through the conduit 73 
to effect movement of the valve 74 to the open or a position to supply 
water to the conduit 40 and the nozzle arrays 32, 34, 36, and 38. With 
electrical power normally available to the machine 10, the valve 72 will 
be in its position b to vent the conduit 73 through the valve 72 back to a 
hydraulic fluid reservoir or tank 75. The valve 74 will remain in the 
closed or b position. 
Thanks to the arrangement of the check valve 68, accumulator 70, control 
valve 72, and the pilot operated control valve 74, fire suppression water 
may be supplied to the machine 10 in the event of electrical power 
interruption. Moreover, conventional mining machines with hydraulic 
control systems generally along the lines illustrated in FIG. 2 may be 
easily adapted to operate with the system of the present invention by 
connecting the conduit 73 to a source of pilot pressure fluid such as 
supplied in the conduit 66 and by interconnecting a water control valve 
with the main water supply conduit 20 and with the conduit leading to the 
fire suppression water spray nozzles. 
Operation of the system illustrated is believed to be readily 
understandable to those of ordinary skill in the art from the foregoing 
description. The components, particularly the check valve 68, accumulator 
70, valve 72, and valve 74 are readily commercially available or are 
believed to be within the purview of the art worker to fabricate and 
furnish in accordance with conventional hydraulic control system or fluid 
power practices. 
Although a preferred embodiment of the present invention has been described 
in detail herein, those skilled in the art will recognize that various 
substitutions and modifications may be made to the invention without 
departing from the scope and spirit of the appended claims.