Wheelchair lift control

Abstract

A wheelchair lift having a logic module which provides several interlocks that promote proper operation is described. Also, a wheelchair lift having an arm geometry which requires a lower peak force for operation is described.

1 . A lift for raising and lowering a load between a ground level and a floor level, the lift comprising: 
 a platform configured for carrying a passenger;    a mounting structure configured to move the platform between a ground level position, a floor level position and a stowed position;    at least one sensor attached to the lift configured to produce a signal in response to a lift condition; and    a logic module configured to control operation of the lift in response to a level of the signal from the sensor.    
     
     
         2 . The lift of  claim 1 , wherein the logic module is configured to adjust a lift operation within a selected time after the logic module detects the signal level from the sensor has reached a set value.  
     
     
         3 . The lift of  claim 2 , wherein the logic module adjusts a speed of a lift operation within a selected time after the logic module detects the signal level from the sensor has reached a set value.  
     
     
         4 . The lift of  claim 1 , wherein the logic module is configured to prevent movement of the lift when the logic module detects the signal level from the sensor has reached a set value.  
     
     
         5 . The lift of  claim 4 , wherein the sensor is associated with the platform and the set value is based on a signal level detected within a selected time after a portion of the platform comes into or out of out of contact with a surface at the ground level position.  
     
     
         6 . The lift of  claim 4 , wherein the set value is based on a curve programmed into the logic module corresponding to signal levels associated with movement of the platform at different points of a lift operation.  
     
     
         7 . The lift of  claim 4 , wherein the set value is based on an amount of weight determined to be present on the platform.  
     
     
         8 . The lift of  claim 7 , wherein the logic module is configured to prevent initiation of movement of the platform if the signal level reaches the set value and a restraint belt associated with the platform is not fastened.  
     
     
         9 . The lift of  claim 8 , wherein the logic module is configured to stop movement of the platform from between the ground level position and the floor level position if the signal level reaches the set value and the restraint belt is not fastened.  
     
     
         10 . The lift of  claim 4 , wherein the logic module is configured to allow manual adjustment of the set value.  
     
     
         11 . The lift of  claim 4 , wherein the logic module is further configured to automatically adjust the set value.  
     
     
         12 . The lift of  claim 11 , wherein the logic module is configured to adjust the set value from a first signal level when moving the platform into the stowed position after moving the platform between the ground level position and the floor level position, to a second signal level when moving the platform into the stowed position after moving the platform away from the stowed position.  
     
     
         13 . The lift of  claim 11 , wherein the logic module is configured to track the average signal level associated with a lift operation and to adjust the set value based on changes to the average.  
     
     
         14 . The lift of  claim 12 , wherein the average signal level does not include signal levels produced by the sensor during failed lift operations.  
     
     
         15 . The lift of  claim 1 , wherein the logic module is configured to adjust the signal level produced by the sensor based on a voltage level detected by another sensor.  
     
     
         16 . The lift of  claim 1 , wherein the logic module is configured to output information related to lift operations to a visual display in the form of alphanumeric codes.  
     
     
         17 . The lift of  claim 16 , further comprising a chart attached to the lift with information giving instructions related to the alphanumeric codes.  
     
     
         18 . The lift of  claim 1 , wherein the logic module is configured to output information to a visual display in multiple languages.  
     
     
         19 . The lift of  claim 1 , wherein the signal level corresponds to one of a pressure level, an electrical level or a weight level detected by the sensor.  
     
     
         20 . The lift of  claim 1 , wherein the logic module is configured to output audible voice information in response to a lift condition.  
     
     
         21 . The lift of  claim 20 , wherein the logic module is configured to output audible voice information in multiple languages.  
     
     
         22 . The lift of  claim 1 , wherein the logic module is configured to adjust operation based on a characteristic of the sensor.  
     
     
         23 . The lift of  claim 22 , wherein the sensor characteristic comprises a sensor scale.  
     
     
         24 . The lift of  claim 1 , wherein the logic module is configured to control operation of the lift in response to a level of the signal from the sensor based on a signal level detected by another sensor.  
     
     
         25 . The lift of  claim 1 , wherein the lift comprises a wheelchair lift for raising and lowering a passenger between a ground level and a floor level.  
     
     
         26 . A method for operating a lift, comprising: 
 providing a platform configured for moving between a ground level position, a floor level position and a stowed position;    receiving a signal from a sensor associated with the lift; and    controlling operation of the lift in response to a level of the signal received by the sensor.    
     
     
         27 . The method of  claim 26 , further comprising adjusting a lift operation within a selected time after the level of the signal from the sensor has reached a set value.  
     
     
         28 . The method of  claim 27 , wherein adjusting the lift operation comprises adjusting a speed of a lift operation.  
     
     
         29 . The method of  claim 26 , wherein controlling the lift comprises preventing movement of the platform when the signal level reaches a set value.  
     
     
         30 . The method of  claim 29 , further comprising selecting the set value based on a signal level detected within a selected time after a portion of the platform is moved away from or into contact with a surface at the ground level position.  
     
     
         31 . The method of  claim 29 , further comprising selecting the set value based on a curve corresponding to signal levels associated with movement of the platform at different points of a lift operation.  
     
     
         32 . The method of  claim 29 , further comprising selecting the set value based on an amount of weight determined to be present on the platform.  
     
     
         33 . The method of  claim 29 , further comprising: 
 detecting whether a restraint belt associated with the platform is fastened; and    preventing initiating movement of the platform from between the ground level position and the floor level position if the set value is exceeded and the restraint belt is not fastened.    
     
     
         34 . The method of  claim 29 , further comprising: 
 stopping movement of the platform from between the ground level position and the floor level position if the signal level reaches the set value and the restraint belt is not fastened.    
     
     
         35 . The method of  claim 29 , further comprising adjusting the set value based on additional data about a lift operation.  
     
     
         36 . The method of  claim 35 , wherein adjusting the set value comprises manually adjusting the set value.  
     
     
         37 . The method of  claim 35 , wherein adjusting the set value comprises automatically adjusting the set value.  
     
     
         38 . The method of  claim 35 , wherein adjusting the set value comprises adjusting the set value from a first signal level when moving the platform into the stowed position after moving the platform between the ground level position and the floor level position, to a second signal level when moving the platform into the stowed position after moving the platform away from the stowed position.  
     
     
         39 . The method of  claim 35 , wherein adjusting the set value comprises tracking the average signal level associated with a lift operation and adjusting the set value based on changes to the average.  
     
     
         40 . The method of  claim 39 , wherein tracking the average signal level does not include tracking signal levels produced by the sensor during failed lift operations.  
     
     
         41 . The method of  claim 26 , further comprising adjusting the signal level produced by the sensor based on a voltage level detected by another sensor.  
     
     
         42 . The method of  claim 26 , further comprising outputting information related to lift operations to a visual display of the lift in the form of alphanumeric codes.  
     
     
         43 . The method of  claim 26 , further comprising outputting information to a visual display of the lift in multiple languages.  
     
     
         44 . The method of  claim 26 , wherein the signal level is selected to correspond to one of a pressure level, an electrical level or a weight level detected by the sensor.  
     
     
         45 . The method of  claim 26 , further comprising outputting audible voice information in response to a lift condition.  
     
     
         46 . The method of  claim 45 , wherein outputting audible voice information comprises outputting audible voice information in multiple languages.  
     
     
         47 . The method of  claim 26 , further comprising adjusting operation based on a characteristic of the sensor.  
     
     
         48 . The method of  claim 47 , wherein the sensor characteristic is selected to comprise a sensor scale.  
     
     
         49 . The method of  claim 26 , further comprising controlling operation of the lift in response to a level of the signal from the sensor based on a signal level detected by another sensor.  
     
     
         50 . The method of  claim 26 , wherein the lift is configured as a wheelchair lift for moving a passenger between the ground level position and the floor level position.