Abstract: Invention is directed to a compression spring mechanism, particularly in combination with a fencing system which incorporates a swinging gate. The mechanism, intended to automatically close a released and opened gate, comprises a cylindrical tube, mounted within the gate, a plurality of compression springs aligned end-to-end within the tube, and a spring housing secured to one end of the tube for receiving one of the compression springs. A cable, of predetermined length, passes through the housing and aligned springs and is secured to the spring end most remote from the spring housing. The other end of the cable is secured to a stationary member, such as a post about which the gate pivots. As the gate is opened, the springs are further compressed storing sufficient energy to allow closure of the gate when released.

Abstract: A laser fluid control apparatus and method provide selective, precise control of the fluid supplied to the laser. The flow of the fluid to the laser can be automatically adjusted according to a selected, programmed control to provide a high volume of the fluid to the laser during initial operation of the laser for a quick warm-up of the laser and a reduced volume after the laser has warmed-up for more economical operation of the laser. Different fluid mixes can also be provided for enhancing laser performance. A control for pulsed or continuous wave laser operation can be actuated to automatically change the composition of the fluid supplied to the laser for continuous wave laser operation as compared to that for pulsed operation.