Abstract: A safe and fun standing and walking-training and play apparatus and method, ideal for infants, new toddlers, and toddlers, is disclosed. The apparatus is lightweight, sturdy, and simple to assemble and disassemble by hand without tools. Further, the system comprises a configuration that is adjustable in height. The system additionally includes attachable play features such as basketball hoops, full and end activity/play tables, material for making a tent, fort-like (or ‘crawl-through’) structure, and soccer (or hockey) goals. Also included is an infant harness attachment and other suspended play items.

Abstract: An child activity system, includes an upper graspable bar, a lower base configured to maintain the combined center of gravity of the child activity system and a child within the extremities of the lower base, and a plurality of attacher bars. The child activity system is configurable by hand between a walking training configuration, a play feature configuration, and a storage configuration.

Abstract: A safe and fun exercise and walking-training apparatus and method that is ideal for infants in the approximate age range of 10 months to 18 months is disclosed. The apparatus is lightweight, very sturdy, very simple, consisting of only six unique elements, and may be assembled and disassembled by hand without tools. A system of attachable play features is also disclosed.

Abstract: A method for cleaning a solenoid-operated regulator valve wherein command current applied to a solenoid actuator establishes a defined response of a valve. Cleaning current pulses applied to the solenoid establish a response that does not interfere with the effectiveness of the valve function. The pulse width, pulse amplitude, pulse direction and pulse period are determined by the degree of contamination of the valve environment.