High pressure washer

A pressurized hot fluid washer apparatus comprising:

• a liquid pump member adapted to being connected to a source of liquid;
• a fuel pump member adapted to being connected to a source of fuel;
• a closed hudraulic pumping system for producing and applying a driving impulse force to both the liquid pump member and the fuel pump member, and a by-pass conduit for by-passing the liquid and fuel pump member;
• a heat exchanger means connected to the liquid pump member for heating the fluid;
• a fuel burner apparatus connected to the fuel pump for supplying heat to the heat exchanger means;
• an output conduit connected to the heat exchanger means for delivering the heated fluid;
• a control valve to regulate fluid flow through the output conduit;
• means for hydraulically sensing the liquid pressure downstream of the liquid pump member;
• hudraulic means for opening the by-pass conduit to automatically stop the fuel pump member and the liquid pump member in response to a sensed predetermined liquid pressure;
• and
• means for reducing the driving impulse force before applying the force to the fuel pump member.

A combination liquid and fuel pumping apparatus for use in a pressurized hot fluid washer having an output conduit for applying the hot fluid, an operator controlled delivery valve, and heat exchanger means for heating the fluid including a fuel burner, comprising:

• a liquid pump member adapted to being connected to the heat exchanger;
• a fuel pump member adapted to being connected to the fuel burner;
• a closed hydraulic prime mover means for applying a driving impulse force to both the liquid pump member and the fuel pump member;
• and
• means for reducing the driving impulse force before applying the force to the fuel pump member.

In a pressurized hot fluid apparatus having an output conduit controlled by a delivery valve, heat exchanger means for heating the fluid, and means for providing fuel to the heat exchanger means, the improvement comprises:

• means for pumping the fluid through the heat exchanger means including a closed hydraulic system having first prime mover pump means for creating impulse forces and a second pump member connected to the hydraulic system for transmitting the impulse forces to the fluid for pumping;
• means for hydraulically sensing the fluid pressure in the output conduit;
• hydraulic means for stopping the flow of fuel in response to a predetermined pressure level which indicates at least a below normal fluid flow through the heat exchanger such as when the delivery valve is closed including a by-pass conduit for by-passing the second pump member, and
• by-pass valve means for controlling the by-pass conduit including a housing member and a by-pass valve spool slidably mounted in the housing member.