Abstract: The present disclosure relates generally to medical devices and, more particularly, to a gas mixing system for a medical ventilator. A gas mixer is provided to adjust the oxygen concentration of environmental air for a blower-based ventilator, by adjusting the mix of air upstream of the ventilator and providing the mixed air to the ventilator's environmental air inlet.

Abstract: An improved circular saw blade is rotatable in a guard casing having tree receiving vertically aligned openings in its upper and lower plates. The blade has a peripheral surface formed in part by a series of replaceable circumferentially spaced teeth with transverse cutting edges positioned to rotate about a predetermined first radius. The blade also has a series of circumferentially spaced, generally radially projecting backer tooth mounts for receiving the rear surfaces of the teeth. The mounts have sloped peripheral surfaces lying radially inside the first radius of rotation and have rear surfaces generally parallel to the mount front surfaces. The saw further has generally tangentially projecting finger-like guides in a guide region spaced circumferentially forwardly from each tooth to provide a radially extending chip passing slot between each tooth and guide and the guides have peripheral surfaces positioned to rotate radially inside the first arc of rotation about a second arc of rotation.

Abstract: A controller couples a modem or facsimile device to a telephone trunk or line and also connects another instrument or communications device to the same line so that the line can be shared without danger of the two devices interfering with one another. The line is divided into separate branches to connect to the two devices. Each branch has a line relay that senses line current in the tip and ring conductors of the respective branch when line current is present. A holding feature accommodates dial pulse interruptions in the line current and/or pulse signalling.

Abstract: Making polymeric extrudates having a smooth surface by feeding a molten polymeric core material through a die cavity wherein a portion of the wall of the die cavity is a rigid microporous structure located upstream from a narrowed flow passage of the die cavity, the microporous structure having a substantially uniform pore size, simultaneously forcing under pressure through the microporous structure about 0.03-10%, based on the total weight of the extrudate, of a low viscosity liquid to form a sheath on the molten polymeric core material thus displacing the polymeric core material before the resulting sheath-core composite enters the narrowed flow passage of the die cavity said process conducted under conditions to produce a pressure drop across the microporous structure of at least 0.10 MPa more than the pressure applied on the polymeric core material.

Abstract: A process for chlorinating or chlorosulfonating polyethylene comprising dissolving polyethylene in a solvent that is a mixture of methylene chloride and trichlorofluoromethane in a weight ratio of 0.3-1.6, reacting the resultant solution with sulfuryl chloride under pressure to maintain reactants, the resulting chlorinated or chlorosulfonated polyethylene and product gases in a single liquid phase, reducing the pressure on or increasing the temperature of the single liquid phase of chlorinated or chlorosulfonated polyethylene and solvent to form two liquid phases, one a polymer-rich phase and the other a solvent-rich phase, and separating the phases.