Sand level monitoring system

Abstract

A system for monitoring a sand reservoir includes: (a) a sand reservoir carried on an off-highway vehicle; and (b) at least one sand level indicator carried by the sand reservoir which provides a visual display external to the sand reservoir indicative of the quantity of sand within the sand reservoir.

What is claimed is: 
     
         1 . A system for monitoring a sand reservoir, comprising:
 a sand reservoir carried on an off-highway vehicle; and   at least one sand level indicator carried by the sand reservoir which provides a visual display external to the sand reservoir indicative of the quantity of sand within the sand reservoir.   
     
     
         2 . The system of  claim 1  wherein the visual display is visible outside a body of the vehicle. 
     
     
         3 . The system of  claim 1  wherein the sand level indicator comprises:
 an opening passing through a sidewall of the sand reservoir; and 
 a transparent lens covering the opening. 
 
     
     
         4 . The system of  claim 3  where the lens has a convex shape which protrudes outward from the sidewall. 
     
     
         5 . The system of  claim 3  wherein the sand level indicator comprises a resilient membrane disposed across the opening, the membrane displaying a first color in a relaxed state, and a second color when pressure is applied thereto. 
     
     
         6 . The system of  claim 1  wherein a plurality of sand level indicators are disposed at varying heights along a sidewall of the sand reservoir, corresponding to varying levels of sand therein. 
     
     
         7 . The system of  claim 1  wherein the sand level indicator comprises:
 a vertical member slidably mounted in an upper portion of the sand reservoir so as to be able to rise and fall with changes in the level of sand in the reservoir; and 
 a foot carried by the vertical member which is adapted to float on a surface of sand within the sand reservoir. 
 
     
     
         8 . The system of  claim 1  wherein the sand level indicator comprises:
 an elongated elastic bladder positioned inside the sand reservoir; 
 a header tank disposed in fluid communication with the bladder; 
 a fluid disposed inside the bladder; 
 wherein the bladder is positioned to span a range of sand levels within the sand reservoir, and arranged such that compression of the bladder by sand causes a change in a fluid level within the header tank; and 
 wherein the fluid level within the header tank is discernable from outside the reservoir. 
 
     
     
         9 . The system of  claim 1  wherein the sand level indicator comprises:
 an elastic bladder positioned inside the sand reservoir; 
 a pressure measuring device disposed outside the sand reservoir and in fluid communication with the bladder; and 
 a fluid disposed inside the bladder. 
 
     
     
         10 . The system of  claim 9  wherein the pressure measuring device is a pressure gauge having a visual display. 
     
     
         11 . The system of  claim 1  wherein the sand level indicator comprises: a first sand level indicator having a visual display visible outside a body of the vehicle; and a second sand level indicator having a visual display visible inside the body of the vehicle. 
     
     
         12 . The system of  claim 1  wherein the sand level indicator comprises a plurality of sensors disposed at varying heights relative to the reservoir, corresponding to varying levels of sand therein, each sensor operable to generate a signal indicative of the presence or absence of sand at the position of the sensor. 
     
     
         13 . The system of  claim 12  wherein each of the sensors is coupled to a visual display mounted on the exterior of the sand reservoir, the visual display indicative of the presence of sand at the height of the corresponding sensor. 
     
     
         14 . The system of  claim 13  wherein the visual display is an electric lamp. 
     
     
         15 . The system of  claim 12  wherein the sensors are coupled to a visual display located remotely from the sand reservoir. 
     
     
         16 . The system of  claim 1  wherein the sand level indicator comprises one or more sensors adapted to generate a signal indicative of the weight of the reservoir. 
     
     
         17 . A system for monitoring a sand reservoir of an off-highway vehicle, comprising:
 an off-highway vehicle unit carrying a sand reservoir;   a sand level indicator comprising at least one sensor which generates a signal indicative of the quantity of sand in the sand reservoir;   a transmitter coupled to the sand level indicator; and   a remote station having a receiver in communication with the transmitter for receiving the signal.   
     
     
         18 . The system of  claim 17  wherein the sand level indicator comprises a plurality of sensors disposed at varying heights relative to the reservoir, corresponding to varying levels of sand therein, each sensor operable to generate a signal indicative of the presence or absence of sand at the position of the sensor. 
     
     
         19 . A system for monitoring a sand reservoir of an off-highway vehicle comprising:
 an off-highway vehicle;   a sand reservoir mounted to the off-highway vehicle for carrying sand;   a sand level indicator carried by the sand reservoir, the sand level indicator configured to monitor a level of sand in the sand reservoir and to generate a signal indicative of a quantity of sand within the sand reservoir;   a processor onboard the off-highway vehicle and in communication with the sand level indicator, the processor configured to receive the signal from the sand level indicator and generate data corresponding to the quantity of sand for transfer to a remote location; and   a transmitter coupled to the processor for transferring the data to a remote location.   
     
     
         20 . The system of  claim 19  further comprising a remote station having a receiver in communication with the transmitter for receiving the data.