Abstract: A pressure washer includes a chassis as well as a liquid pump, a pump-driving prime mover, plural chemical product containers and a product selecting valve, all supported by the chassis. Each of the containers is attached to a separate valve conduit extending to the valve and the valve is connected to a device conduit extending to the mixing device. A distributor is mounted for movement with respect to the valve body and has a channel for selectively connecting one of the valve conduits to the device conduit. The user may thereby use the pressure washer to dispense any one of plural solutions. A fresh water container facilitates “wash out” of the valve and device conduit before switching to another chemical product.

Abstract: A pressure washer is powered by a prime mover, e.g., an electric motor or an internal combustion engine, and has a flow control valve. The valve has a housing containing a piston assembly and the assembly has a mechanism coupled to it for controlling prime mover power. The piston assembly includes a first piston sealing against the housing and dividing the housing interior into two chambers. Such first piston is spring-biased to a first position during periods when no output flow is being demanded from the washer. The assembly also has a second piston spring-biased to seal against the first piston during periods of no flow. When flow is demanded by opening the nozzle, the pressure in the second chamber diminishes. And when the difference between the pressure in the second chamber and that in the first chamber exceeds a predetermined value, the assembly shifts to a second position, causing the mechanism to actuate the prime mover.

Abstract: Disclosed is a piston for a water pump, e.g., a pressure washer pump. The piston includes a piston body and a piston head and in the improvement, the piston body is solid, homogeneous ceramic. That is, the piston body has a generally cylindrical surface and the body is circumscribed by the surface and is homogeneous ceramic. A method for making a piston for a water pump includes the steps of providing a piston body made of a ceramic material, and making a piston head of steel and having a pocket formed therein. The head is heated, the pocket and the body are engaged in overlapping relationship and the head is allowed to cool and "shrink-fit" to the piston body. The piston head is formed to have a relief groove circumscribing the pocket for reducing compression forces resulting from such cooling.

Abstract: The disclosure involves a prime mover and a pump-mount adapter mounted thereto. The adapter includes a central housing and a plurality of arms extending radially outwardly from the housing and coupled to the prime mover. Resilient mounts are used for such coupling and a rigid compression limiter prevents such mounts from being compressed to the degree that substantial resiliency is lost. The housing contains a liquid lubricant for lubricating the pump. A resilient seal device is between the housing and the prime mover and retains the lubricant in the housing. And after assembly, the housing is maintaining in a spaced relationship to the prime mover. The new mounting arrangement permits relatively generous manufacturing tolerances while yet permitting the prime mover and adapter-mounted pump to radially and angularly "self-align" during assembly.