Air purging of a liquid dispensing system of a surface cleaner

Abstract

A surface cleaner includes a liquid dispensing system comprising a fluid flow path configured to receive a flow of liquid, a pump, an air purging component, and a valve actuator. The pump is in line with the fluid flow path and is configured to drive the flow of liquid through the fluid flow path. The air purging component includes an inlet in line with the fluid flow path, an outlet, an airflow path connecting the inlet and the outlet, and a valve in line with the airflow path. The valve includes an open position in which the airflow path is open between the inlet and the outlet and a closed position in which the airflow path is closed between the inlet and the outlet. The valve actuator is connected to the valve and is configured to bias the valve in the open position when air is detected in the fluid flow path.

1 . A surface cleaner including a liquid dispensing system comprising: 
 a fluid flow path configured to receive a flow of liquid;    a pump in line with the fluid flow path and configured to drive the flow of liquid through the fluid flow path;    an air purging component including an inlet in line with the fluid flow path, an outlet, an airflow path connecting the inlet and the outlet, and a valve in line with the airflow path and having an open position in which the airflow path is open between the inlet and the outlet and a closed position in which the airflow path is closed between the inlet and the outlet; and    a valve actuator connected to the valve and configured to bias the valve in the open position when air is detected in the fluid flow path.    
     
     
         2 . The surface cleaner of  claim 1 , wherein the valve actuator is configured to bias the valve in the closed position when liquid is detected in the fluid flow path.  
     
     
         3 . The surface cleaner of  claim 1 , including a sensor configured to detect air in the fluid flow path, wherein the valve actuator biases the valve in the open position in response to the detection of air in the fluid flow path by the sensor.  
     
     
         4 . The surface cleaner of  claim 1 , wherein the air purging component includes a non-return stage in line with the airflow path, which prevents air from entering the fluid flow path through the outlet of the air purging component.  
     
     
         5 . The surface cleaner of  claim 1 , wherein the inlet of the air purging component is coupled to the fluid flow path downstream of the pump relative to a downstream direction in which the pump is configured to drive the flow of liquid.  
     
     
         6 . The surface cleaner of  claim 1 , wherein the inlet of the air purging component is coupled to the fluid flow path upstream of the pump relative to a downstream direction in which the pump is configured to drive the flow of liquid.  
     
     
         7 . The surface cleaner of  claim 1 , wherein: 
 the fluid flow path includes a section of conduit that is elevated relative to the pump; and    the inlet of the air purging component is coupled to the section of conduit.    
     
     
         8 . The surface cleaner of  claim 1  including a flow restriction member having an upstream inlet and a downstream outlet relative to a downstream direction in which the pump is configured to drive the flow of liquid, wherein a pressure drop occurs across the flow restriction member when a flow of liquid travels through the flow restriction member.  
     
     
         9 . The surface cleaner of  claim 1  including: 
 a rotatable scrubbing member configured to scrub a surface; and    a vacuumized fluid recovery device configured to remove fluid from the surface.    
     
     
         10 . The surface cleaner of  claim 1  including a cleaning agent dispensing system comprising: 
 a cleaning agent container attached to the mobile body;    a cleaning agent flow path connected to the cleaning agent container and configured to receive a flow of cleaning agent from an interior cavity of the cleaning agent container; and    a flow control device having a first input connected to the cleaning agent flow path, a second input connected to the fluid flow path, and an output in line with the first and second inputs.    
     
     
         11 . The surface cleaner of  claim 10  including an aerator having an inlet in line with the output of the flow control device, and outlet, and a gas inlet, the aerator configured to receive an output flow of cleaning liquid at the inlet, inject gas into the output flow of cleaning liquid through the gas inlet, and produce an output flow of foamed cleaning liquid through the outlet.  
     
     
         12 . A surface cleaner comprising: 
 a liquid dispensing system comprising:    a fluid flow path configured to receive a flow of liquid;    a pump in line with the fluid flow path and configured to drive the flow of liquid through the fluid flow path;    an air purging component including an inlet in line with the fluid flow path, an outlet, an airflow path connecting the inlet and the outlet, and a valve in line with the airflow path and having an open position in which the airflow path is open between the inlet and the outlet and a closed position in which the airflow path is closed between the inlet and the outlet;    a valve actuator connected to the valve and configured to bias the valve in the open position when air is detected in the fluid flow path;    a rotatable scrubbing member configured to scrub a surface; and    a vacuumized fluid recovery device configured to remove fluid from the surface.    
     
     
         13 . The surface cleaner of  claim 12 , wherein the valve actuator is configured to bias the valve in the closed position when liquid is detected in the fluid flow path.  
     
     
         14 . The surface cleaner of  claim 12 , including a sensor configured to detect absence of liquid in the fluid flow path, wherein the valve actuator biases the valve in the open position in response to the detection of air in the fluid flow path by the sensor.  
     
     
         15 . The surface cleaner of  claim 12 , wherein the inlet of the air purging component is coupled to the fluid flow path downstream of the pump relative to a downstream direction in which the pump is configured to drive the flow of liquid.  
     
     
         16 . The surface cleaner of  claim 12 , wherein: 
 the fluid flow path includes a section of conduit that is elevated relative to the pump; and    the inlet of the air purging component is coupled to the section of conduit.    
     
     
         17 . The surface cleaner of  claim 12  including a flow restriction member having an upstream inlet and a downstream outlet relative to a downstream direction in which the pump is configured to drive the flow of liquid, wherein a pressure drop occurs across the flow restriction member when a flow of liquid travels through the flow restriction member.  
     
     
         18 . A method of purging air from a liquid dispensing system of a surface cleaner comprising steps of: 
 providing a pump configured to drive a flow of liquid through a fluid flow path of the liquid dispensing system;    driving a pump;    detecting one of the presence of air and liquid in the fluid flow path;    opening an airflow path connected to the fluid flow path through which the air is discharged from the fluid flow path in response to a detection of air in the fluid flow path in the detecting step; and    closing the airflow path in response to a detection of liquid in the fluid flow path in the detecting step.    
     
     
         19 . The method of  claim 18  including preventing air from entering the fluid flow path through the airflow path when the airflow path is opened.  
     
     
         20 . The method of  claim 18  wherein: 
 the surface cleaner includes an air purging component including an inlet in line with the fluid flow path, an outlet, the airflow path connecting the inlet and the outlet open to ambient air, and a valve in line with the airflow path and having an open position in which the airflow path is open between the inlet and the outlet and a closed position in which the airflow path is closed between the inlet and the outlet;    the automatically opening step includes biasing the valve to the open position; and    the automatically closing step includes biasing the valve to the closed position.    
     
     
         21 . The method of  claim 18  including providing a flow restriction member in line with the fluid flow path, the flow restriction member having an upstream inlet and a downstream outlet relative to a downstream direction in which the pump is configured to drive the flow of liquid, wherein a pressure drop occurs across the flow restriction member when the pump drives a flow of liquid through the flow restriction member.