Abstract: A foldable shutter for protecting sliding glass doors from storms and break-ins is formed of vertical panels hinged together. The panels are extruded with full length beads on both sides and are held together by long extruded hinge clips having separate channels into which beads of adjacent panels fit. These hinge clips are substantially longer than the panels and the ends are closed by closure members having pins extending into the channel and spacing the panels from the ends. These closure members support the shutter on rollers in an upper guide and guide the bottom of the shutter in a lower guide. The hinges have three separate functions--to hold the panels together, to support the shutters, and to hold the shutters in place in the guides. Locking end trim sections for the shutter are hinged to the end panels and are also longer than the panels for support and guidance.

Abstract: A solenoid which is driven positively in both directions by reversal of coil current and held in place at either end by flux from a permanent magnet located at the center of the frame. The permanent magnet is formed of two opposed sections fitting tightly between the plunger tube and frame, and is located in a space between two coils. In one form the two magnet sections are formed of compressible material and are recessed to fit closely around the plunger tube.

Abstract: A three way slide valve includes a rectangular valve slide fitted into a housing formed of two halves having mating flat surfaces. Each housing half is recessed to provide a chamber for the valve slide and also a spring chamber which restrains both ends of a double acting return spring. One end of the return spring engages one end of the valve slide and the other part of the spring engages a loop on the valve slide for return to center action. Ports in the housing halves are provided with shear seals in engagement with the valve slide.

Abstract: The ball in a ball type check valve is guided by a wire form ball cage. The cage is formed of two spring wire pieces each having two ball guiding legs, attached by cross members formed with interfitting loops which hold the pieces together by spring tension. Each guiding leg is formed with a reverse bend extending outwardly and then rearwardly along the valve body walls, this positioning the guide in the valve body. The cage is formed larger than the inside of the valve body in which it fits and also serves as a retainer for the ball valve spring. The assembly of the cage, spring and ball valve is inserted through the outlet port and the cage expands behind a shoulder in the body, locking it in place by spring tension.

Abstract: A pressure responsive semi-automatic directional control valve for controlling a hydraulic cylinder. Manual movement of the valve from neutral to starting position applies pressure to one side of the cylinder. The pressure buildup at the end of this stroke causes the valve to move to return position. The pressure build up at the end of the return stroke then causes the valve to return to neutral position.A modification causes movement of the valve back to starting position thus providing continuous repeat cycle operation of the control valve.

Abstract: A two speed manual preset timer in which the cam shaft is driven by a pair of constantly meshing gears having two mating segments of different but constant pitch radii. One pair of segments gives relatively high shaft speed in a sector of the timing range adjacent the OFF position for accuracy in short timings. The other pair of segments gives relatively slow shaft speed in a sector at the other end of the timing range for long timings. The segments of the gears are joined by transition segments of varying pitch radii, providing a sector of varying shaft speed between the short timing and long timing sectors.

Abstract: A continuous repeat cycle timer in which the on period is externally adjustable. The beginning of the on period is fixed, being started by a cam follower dropping into a notch in the periphery of a cam. The end of the on period is determined by axial movement of a second cam which releases a latch. The point of axial latch releasing movement is set by an adjusting cam which is rotatable by an external knob. The cam shaft for the operating cams extends through the knob and indicates the progress of the time cycle.

Abstract: A regular manual lever operated directional control valve is converted to a remote pilot controlled valve without loss of the manual operation feature. A double acting cylinder is attached to the end of the valve housing remote from the manual lever and the piston rod in the cylinder is directly attached to the valve spool. Semi-automatic operation is provided by mounting a valve positioning unit to the end of the operating cylinder and attaching it to the other end of the piston rod. This unit includes pressure released detent mechanism. Pressure buildup in the valve ports is transmitted to a detent release piston by passages through the valve spool and piston rod.