Electrical control for pressurized flow device

Abstract

A pressure washer has an inlet and an outlet, a pump assembly in fluid communication with the inlet and the outlet, and a motor which drives the pump assembly. A flow switch is disposed upstream of the pump assembly, and is electrically connected to the motor. Configured to be extended with a biasing structure towards the inlet, an axially displaceable flow plunger seals the pump assembly from fluid communication with the inlet. The flow plunger is also configured to be retracted when a fluid force of a fluid from the inlet overcomes the bias of the biasing structure. When the flow plunger is retracted, the flow plunger automatically turns the pressure washer motor on.

1 . A pressure washer comprising: 
 an inlet and an outlet;    a pump assembly in fluid communication with said inlet and said outlet;    a motor configured for driving said pump assembly;    a flow switch disposed upstream of said pump assembly and electrically connected to said motor, said flow control switch including, an axially displaceable flow plunger configured to be extended with a biasing structure towards said inlet to seal said pump assembly from fluid communication with said inlet; and    said flow plunger is configured to be retracted when the bias of said biasing structure is overcome by a fluid force of a fluid from said inlet, wherein the retraction of said flow plunger automatically turns said motor on.    
   
   
       2 . The pressure washer of  claim 1  further comprising an inlet conduit in fluid communication with said inlet wherein said flow switch is disposed in said inlet conduit.  
   
   
       3 . The pressure washer of  claim 2  wherein said flow switch further comprises a contact portion located in said inlet conduit and having at least two contacts configured to displace and electrically connect.  
   
   
       4 . The pressure washer of  claim 3  wherein said flow switch further comprises at least one magnet axially displaceable with said flow plunger wherein the relative movement of said at least one magnet with respect to said contacts causes said contacts to make electrical contact in the presence of a magnetic field, wherein said electrical contact automatically turns said motor on.  
   
   
       5 . The pressure washer of  claim 4  further comprising a shaft axially aligned with and located in said inlet conduit wherein said contacts are disposed in said shaft, and said flow plunger and said at least one magnet are axially displaceable relative to said shaft.  
   
   
       6 . The pressure washer of  claim 2  further comprising a sealing lip peripherally disposed at an upstream end of said flow plunger for sealingly engaging an inlet side of said inlet conduit and preventing fluid communication between said inlet conduit and said pump assembly.  
   
   
       7 . The pressure washer of  claim 2  further comprising a fitting on said inlet conduit opposite said inlet wherein said biasing structure is located in said inlet conduit between said fitting and said flow plunger.  
   
   
       8 . The pressure washer of  claim 4  wherein said at least one magnet is disposed on said flow plunger between an interior wall and a peripheral wall, and is configured to generally circumscribe said contacts.  
   
   
       9 . The pressure washer of  claim 1  wherein said motor is automatically turned off when one of fluid flow is not permitted through the outlet and the flow is insufficient to counter the bias of said biasing structure.  
   
   
       10 . The pressure washer of  claim 2  wherein said motor is automatically turned on in one of a predetermined amount of flow and a positive flow through said conduit.  
   
   
       11 . The pressure washer of  claim 1  wherein said motor is automatically turned on at a fluid pressure of about 40 psi at said flow plunger.  
   
   
       12 . The pressure washer of  claim 1  wherein the pressure of said fluid delivered from said outlet increases to between 1200-1500 psi within 0.5 seconds of said motor being turned on.  
   
   
       13 . A soft start system for a pressure washer comprising: 
 an inlet and an outlet in fluid communication;    a pump assembly disposed between said inlet and said outlet;    a flow switch disposed in fluid communication with and upstream of said pump assembly, said flow control switch electrically connected to a motor and having a circuit configured to be opened or closed;    at least two contacts disposed on said circuit configured to displace and electrically connect in the presence of a magnetic field to close the circuit;    at least one magnet disposed in said switch and moveable with respect to said contacts; and    a biasing structure configured to bias said at least one magnet in an extended position to open the circuit, except when there is a predetermined amount of fluid flow from said inlet and said biasing structure is overcome by fluid force to move said at least one magnet to a retracted position to close the circuit, wherein said closed circuit turns the motor on and drives said pump assembly to deliver the fluid under pressure through said outlet.    
   
   
       14 . The soft start system of  claim 13  wherein said switch is configured to automatically turn the motor on when there is positive fluid flow from said inlet.  
   
   
       15 . The soft start system of  claim 13  wherein said switch is configured to automatically turn the motor on after one of a slight delay and almost immediately after the circuit is closed so that pumping does not occur without said fluid in said pump assembly.  
   
   
       16 . The soft start system of  claim 13  wherein said switch is configured to automatically turn said motor on before a high pressure spike occurs in said pump assembly.  
   
   
       17 . The soft start system of  claim 13  wherein the pressure of said fluid delivered from said outlet increases to between 1200-1500 psi within 0.5 seconds of said motor being turned on.  
   
   
       18 . A flow switch for a pressure washer electrically connected to a motor and located in an inlet conduit downstream of an inlet and upstream of a pump assembly, said flow switch for automatically turning the motor on in the pressure washer comprising: 
 an axially displaceable flow plunger configured to be extended and retracted within the inlet conduit under a biasing force, wherein when said flow plunger is extended under said biasing force, the inlet is sealed off from fluid communication with the pump assembly, and when said flow plunger is retracted by fluid force overcoming said biasing force, the inlet is in fluid communication with the pump assembly, wherein the retraction of said flow plunger automatically turns the motor on.    
   
   
       19 . The flow switch of  claim 18  further comprising a reed switch located in the inlet conduit and having at least two contacts configured to displace and electrically connect in the presence of a magnetic field.  
   
   
       20 . The flow switch of  claim 19  further comprising at least one magnet disposed in said reed switch and axially displaceable with said flow plunger wherein the relative movement of said magnet with respect to said contacts causes said contacts to make electrical contact, wherein said electrical contact automatically turns said motor on.  
   
   
       21 . The flow switch of  claim 18  further comprising a shaft axially aligned with and located in said inlet conduit wherein said contacts are disposed in said shaft and said flow plunger and said at least one magnet are axially displaceable relative to said shaft.  
   
   
       22 . The flow switch of  claim 18  wherein said motor is automatically turned off when one of fluid flow is not permitted through the outlet and the flow is insufficient to counter said biasing force.  
   
   
       23 . A pressure washer comprising: 
 an inlet and an outlet;    an inlet conduit in fluid communication with said inlet;    a pump assembly in fluid communication with said inlet and said outlet;    a motor configured for driving said pump assembly;    a flow switch disposed in said inlet conduit and electrically connected to said motor, said flow control switch including, 
 a reed switch having a circuit configured to be closed when a fluid force is exerted on said switch and opened in the absence of said fluid force, wherein when said circuit is closed said motor is automatically turned on and when said circuit is opened said motor is automatically turned off.