Abstract: The disclosure discloses a convexity adjusting mechanism for a working roll of a straightening machine and relates to the field of plate straightening devices. The convexity adjusting mechanism for the working roll of the straightening machine comprises a transmission shaft, a plurality of convexity adjusters, working rolls and supporting rolls corresponding to each convexity adjuster. The transmission shaft, the supporting rolls and the working rolls are axially parallel; the convexity adjust comprises a sleeve, a cam and a controller; the cam is provided with a through hole, the sleeve is mounted in the through hole, and the cam is sleeved on the transmission shaft through the sleeve; the sleeve is connected with the controller, and one end of the sleeve is provided with a gripping clawt.

Abstract: An anesthetic laryngoscope for manual oxygen jet-ventilation, including a handle with a handle housing having a lower end, a first oxygen supply tube, and a battery container mounted in the handle housing. A blade having an observation light and a second oxygen supply tube mounted thereon is mounted on the lower end of the handle means. The first oxygen supply tube is connected to the second oxygen supply tube, and a manual oxygen on/off valve is provided on one of the first and second oxygen supply tubes. Preferably, the manual oxygen on/off valve is a manually controlled two-position, two-way valve to enable generation of a pulsing supply of oxygen through an ejector nozzle at the end of the second oxygen supply tube.