Disarm device

Abstract

A disarm device for use with a hitch arrangement on a working arm of a working machine, the device comprising a measurement device for measuring a property associated with the arm which can be used to determine whether or not a working implement carried by a working arm is sufficiently supported by a surface on to which it is to be released.

1 . A disarm device for use with a hitch arrangement on a working arm of a working machine, the device comprising a measurement device for measuring a property associated with the arm which can be used to determine whether or not a working implement carried by a working arm is sufficiently supported by a surface on to which it is to be released. 
     
     
         2 . A disarm device according to  claim 1 , in which the measurement device provides a signal to a controller which determines whether or not the working implement carried by the working arm is sufficiently supported by a surface onto which it is to be released based on the measured property. 
     
     
         3 . A disarm device according to  claim 2 , in which the controller is configured to receive a signal from the measurement device indicative of the property measured prior to processing the signal to determine whether or not the working implement is sufficiently supported by a surface on which it is to be released and, in the event that the implement is not sufficiently supported by a surface on which it is to be released, to perform a safety function. 
     
     
         4 . A disarm device according to  claim 1 , in which, where the working arm is driven by hydraulics, the measurement device is a pressure sensor. 
     
     
         5 . A disarm device according to  claim 4 , in which the controller determines whether or not the working implement carried by the working arm is sufficiently supported by a surface on which it is to be released by comparing the sensed pressure with a pressure threshold level. 
     
     
         6 . A disarm device according to  claim 1 , in which the measurement device is a load sensor on the hitch arrangement for measuring a load on the hitch. 
     
     
         7 . A disarm device according to  claim 6 , in which the controller determines whether or not the working implement carried by a working arm is sufficiently supported by a surface on which it is to be released by comparing the measured load on the hitch with a load threshold level. 
     
     
         8 . A disarm device according to  claim 1 , further comprising one or more sensors configured to determine an orientation of a working implement secured to the hitch arrangement and to output a signal indicative of the orientation of a working arm or working implement secured to the hitch arrangement with respect to gravity, the controller then being configured to receive the signal from the one or more sensors and to perform a safety function in response to receipt of the signal such that the safety function is performed if the orientation of the working arm or working implement secured to the hitch arrangement with a respect to gravity is an unpermitted orientation. 
     
     
         9 . A disarm device according to  claim 8 , in which the controller uses a signal from the measurement device measuring the property associated with the arm to determine whether or not a working implement carried by a working arm is sufficiently supported by a surface on which it is to be released in combination with a signal from the one or more sensors configured to determine an orientation of a working arm or working implement attached to the hitch arrangement indicative of orientation of a working implement. 
     
     
         10 . A disarm device according to  claim 3 , in which the safety function comprises the controller either disarming or locking the hitch arrangement to prevent inadvertent release of the working implement secured to the hitch arrangement. 
     
     
         11 . A disarm device according to  claim 3 , the safety function comprises providing an indication to the user. 
     
     
         12 . A method of operating a hitch arrangement on a working arm of a working machine comprising the steps of:
 providing a working arm having a hitch arrangement, providing a working implement attached to the arm by means of the hitch arrangement, measuring a property associated with the arm, using the measured property to determine whether or not a working implement carried by the working arm is sufficiently supported by a surface on which it is to be released, and, on determining that the tool is sufficiently supported, permitting operation of the hitch arrangement to effect release of the tool.   
     
     
         13 . A method of operating a hitch arrangement on a working arm comprising steps of:
 providing a working arm having a hitch arrangement, providing a working implement attached to the working arm by means of the hitch arrangement, measuring a property associated with the arm, using the measured property to determine whether or not a working implement carried by the working arm is sufficiently supported by a surface on which it is to be released, and, on determining that the tool is not sufficiently supported, preventing operation of the hitch arrangement so as to prevent release of the working implement.   
     
     
         14 . A method of operating a hitch arrangement according to  claim 13 , in which the step of measuring a property associated with the arm is measuring the pressure in a hydraulic circuit used to drive the arm. 
     
     
         15 . A method of operating a hitch arrangement according to  claim 14 , in which the step of using the measured property to determine whether or not the tool carried by the arm is sufficiently supported by a surface on which it is to be released involves comparing the measured pressure with a pressure threshold level. 
     
     
         16 . A method of operating a hitch arrangement according to  claim 13 , in which the step of measuring a property associated with the arm comprises measuring a load carried by the hitch arrangement. 
     
     
         17 . A method of operating a hitch arrangement according to  claim 16 , in which the step of using the measured property to determine whether or not the working implement carried by the arm is sufficiently supported by a surface on which it is to be released comprises comparing the measured load with a load threshold level. 
     
     
         18 . A method of operating a hitch arrangement according to  claim 13 , further comprising the step of determining an orientation of a working arm or a working implement secured to the hitch arrangement and determining the orientation of a working arm or a working implement secured to the hitch arrangement with respect to gravity and determining whether or not the orientation of a working arm or a working implement secured to the hitch arrangement with respect to gravity is an unpermitted orientation. 
     
     
         19 . A method of operating a hitch arrangement according to  claim 13 , the method further comprising the step of indicating to the user that the operation of the hitch arrangement is not permitted.