Hydraulic Ride Control System with Manual Mode Safeguard

Abstract

A hydraulic ride control system for mobile machine having an implement is disclosed. The ride control system may include a hydraulic actuator extending from the machine and connected to an implement, an accumulator, a valve controlling fluid flow between the hydraulic actuator and the accumulator, a sensor, a ride control selection switch and, a controller receiving signals from the sensor and the ride control selection switch and when the ride control switch is in manual position, only allowing fluid flow between the hydraulic actuator and the accumulator when the sensor indicates a predetermined value.

What is claimed is: 
     
         1 . A hydraulic ride control system for a mobile machine having an implement, the system comprising:
 a hydraulic actuator extending from the machine and connected to an implement;   an accumulator;   a valve controlling fluid flow between the hydraulic actuator and the accumulator;   a sensor;   a ride control selection switch; and   a controller receiving signals from the sensor and the ride control selection switch and, when the ride control switch is in manual position, only allowing fluid flow between the hydraulic activator and the accumulator when the sensor indicates a predetermined value.   
     
     
         2 . The hydraulic ride control system of  claim 1 , wherein the sensor is a parking brake position sensor and the predetermined value indicates that the parking brake is engaged. 
     
     
         3 . The hydraulic ride control system of  claim 1 , wherein the sensor is a mobile machine speed sensor and the predetermined value indicates the mobile machine is not moving. 
     
     
         4 . The hydraulic ride control system of  claim 1 , wherein the sensor is a mobile machine gear sensor and the predetermined value indicates the mobile machine is in neutral. 
     
     
         5 . The hydraulic ride control system of  claim 1 , wherein the sensor is an implement lever position sensor and the predetermined value indicates the implement is on the ground. 
     
     
         6 . The hydraulic ride control system of  claim 1 , wherein the ride control selection switch is adapted to be in one of an auto, off, and manual position. 
     
     
         7 . A method of controlling ride of a mobile machine having an implement, the method comprising:
 detecting the position of a ride control switch;   sensing a parameter indicative of movement of the mobile machine; and   when the ride control switch is detected to be in a manual mode, allowing activation of ride control only when the sensed parameter indicates the mobile machine is not moving.   
     
     
         8 . The method of  claim 7 , wherein the ride control switch has auto, off and manual positions, and the detecting determines if the ride control switch is in the manual mode. 
     
     
         9 . The method of  claim 7 , wherein the mobile machine includes a parking brake and the sensing a parameter involves sensing a position of a parking brake to ensure the parking brake is engaged. 
     
     
         10 . The method of  claim 7 , wherein the mobile machine includes a machine speed sensor and the sensing a parameter involves sensing a speed of the mobile machine to ensure the mobile machine is stationary. 
     
     
         11 . The method of  claim 7 , wherein the mobile machine includes a gear sensor and the sensing a parameter involves sensing the gear a transmission of the mobile machine is in to ensure the mobile machine is in neutral. 
     
     
         12 . The method of  claim 7 , wherein the mobile machine includes an implement lever position sensor, and the sensing a parameter involves sensing the position of the implement lever to ensure the implement is on the ground. 
     
     
         13 . A mobile machine, comprising:
 a chassis;   an engine supported on the chassis;   a traction device supporting the chassis;   an implement movably connected to the chassis;   a hydraulic actuator connected between the implement and the chassis;   a ride control system;   a ride control selection switch;   a sensor sensing a parameter indicative of movement of the mobile machine; and   a controller engaging the ride control system when the ride control selection switch is in a manual mode only if a sensed parameter from the sensor reaches a predetermined value.   
     
     
         14 . The mobile machine of  claim 13 , wherein the mobile machine further includes a parking brake and the sensor senses whether the parking brake is engaged. 
     
     
         15 . The mobile machine of  claim 13 , wherein the mobile machine further includes a speed sensor and the sensor senses whether the mobile machine is stationary. 
     
     
         16 . The mobile machine of  claim 13 , wherein the mobile machine further includes a gear sensor and the sensor senses whether the gear is in neutral. 
     
     
         17 . The mobile machine of  claim 13 , wherein the mobile machine further includes an implement lever position sensor and the sensor senses whether the implement is on the ground. 
     
     
         18 . The mobile machine of  claim 13 , wherein the ride control selection switch has auto, off, and manual positions. 
     
     
         19 . The mobile machine of  claim 18 , wherein the ride control system includes an accumulator and a valve between the accumulator and the hydraulic actuator. 
     
     
         20 . The mobile machine of  claim 19 , wherein the controller only allows fluid communicator between the accumulator and the hydraulic actuator through the valve when the ride control selection switch is in the manual position, and when the sensor senses that the mobile machine is stationary.