Abstract: A switchable privacy display comprises a spatial light modulator with output polariser, a reflective polariser, a polar control liquid crystal retarder and an additional polariser. The electrodes of the polar control liquid crystal retarder are patterned with a mark. In wide angle and narrow angle operational modes, the electrodes of the liquid crystal retarder are driven such that the mark is not visible. In a mark display state, the electrodes are driven to provide visibility of the mark in reflected light to an off-axis observer.

Abstract: The method may include putting fresh cleaning liquid in the trolley bucket assembly bucket and the vacuum recovery tank; and, while propelling the system across hard surface flooring: dispensing fresh cleaning liquid from the bucket onto flooring by adjusting the spigot; spreading fresh cleaning liquid on flooring with the liquid spreader assembly; and vacuuming soil and cleaning liquid from flooring into the tank with the squeegee head assembly. The method may further include, when a desired amount of cleaning liquid has been dispensed from the bucket, or a desired amount of cleaning liquid has been vacuumed into the tank: stopping dispensing of cleaning liquid from the bucket; stopping propelling of the system; and transferring a desired amount of cleaning liquid from the tank to the bucket via the cleaning liquid transfer outlet. In addition, the method may include resuming propelling the system across flooring while also: dispensing; spreading; and vacuuming.

Abstract: A cleaning system may have a trolley bucket assembly, a vacuum recovery tank, and a vacuum motor assembly. The trolley bucket assembly may have a bucket, a wheeled chassis, and a spigot fluidly connected to the bucket. A user may dispense and regulate the flow of cleaning liquid from the bucket through the spigot by manually adjusting the spigot. The tank may hold cleaning liquid and soil, and may have a bottom wall, a vacuum recovery inlet, and a transfer outlet through which cleaning liquid may be transferred to the bucket for reuse. The bottom wall may have an interior surface; and the transfer outlet may have an entry opening through which cleaning liquid from the tank enters the transfer outlet. The entry opening may be positioned above a portion of the interior surface, thereby inhibiting soil that settles on the interior surface portion from passing through the transfer outlet.

Abstract: In one aspect, the invention is directed to a cleaning machine that includes a fresh liquid tank, a vacuum tank, and an electromechanical assembly—with the electromechanical assembly including an electromechanical housing, a pump, and a vacuum motor. In this particular aspect of the invention, the pump and the vacuum motor are mounted to the electromechanical housing; and the electromechanical assembly is releasably connected to the fresh liquid tank. In another aspect, the invention is directed to a method for rapid replacement of the electromechanical components of the cleaning machine described immediately above. The method includes disconnecting the electromechanical assembly from the fresh liquid tank, and connecting a replacement electromechanical assembly to the fresh liquid tank.

Abstract: A cleaning system may have a trolley bucket assembly, a vacuum recovery tank, and a vacuum motor assembly. The trolley bucket assembly may have a bucket, a wheeled chassis, and a spigot fluidly connected to the bucket. A user may dispense and regulate the flow of cleaning liquid from the bucket through the spigot by manually adjusting the spigot. The tank may hold cleaning liquid and soil, and may have a bottom wall, a vacuum recovery inlet, and a transfer outlet through which cleaning liquid may be transferred to the bucket for reuse. The bottom wall may have an interior surface; and the transfer outlet may have an entry opening through which cleaning liquid from the tank enters the transfer outlet. The entry opening may be positioned above a portion of the interior surface, thereby inhibiting soil that settles on the interior surface portion from passing through the transfer outlet.

Abstract: One version of the portable liquid-evacuation device may include: a container having a top wall, a bottom wall, a sidewall, a liquid inlet, a liquid outlet, and an air outlet, with the air outlet being connectable to a remote vacuum source; a pump positioned in the container, with the pump including a pump outlet; and a conduit extending from the pump outlet to the liquid outlet. In this particular version, the device may be free of both an integral vacuum source and a float-activated liquid-inlet closure. In another version, the device may include: a top wall including a liquid outlet; a pump attached to the top wall, with the pump including a pump inlet and a pump outlet; and a conduit extending from the pump outlet to the liquid outlet. In this version, the device may be free of a container sidewall and a container bottom wall.

Abstract: A spray gun is connected to a source of pressurized liquid. In one aspect, the worker positions the nozzle of the spray gun into the bowl, adjacent the lower, interior edge of the rim, and aims the liquid outlet of the spray gun toward the primary interior surface of the bowl adjacent the lip of the rim. The worker then rotates the spray gun in a radial manner about the bowl, with the liquid outlet of the spray gun oriented toward the primary interior surface of the bowl adjacent the lip of the rim, while spraying a liquid through the liquid outlet of the spray gun. The worker may rest the spray gun nozzle against the lower, interior edge of the rim during the rotating step, thereby using the lower, interior edge as a guide to facilitate directional control of the liquid being sprayed from the spray gun.

Abstract: A check valve is provided for use in the tubing string of a fluid producing well. The check valve is removably seated within the restricted diameter of a seating nipple in the tubing string. Resilient holddown means at the base of the valve are provided for this purpose. The check valve comprises a hollow generally tubular body having a pierceable valve element positioned therein, the valve opens and closes in response to fluid pressures bearing thereon. To equalize the pressures above and below the valve the pierceable valve element may be ruptured by a conventional wireline spear, allowing the fluid to drain slowly through the valve.

Abstract: A cooperating arrangement of two side panels and a middle interconnecting panel therebetween forming a self-standing display due to the H-shape presented by the bottom edges of said panels in relation to a floor or support surface, and wherein from said erect condition the panels fold into a more compact condition more suitable for storage and shipment of the display.