Abstract: A dental handpiece equipped with an improved rotor cartridge and, in particular, a rotor cartridge replacement assembly for such a handpiece. The rotor cartridge takes the form of a subassembly of a rotor, bearings for the rotor, resilient rings supporting the bearings, and a plastic cup member extending about the lower bearing assembly and the resilient support ring therefor. In addition to the rotor cartridge, the replacement assembly may also include a threaded cap and a support tool which not only holds the cap and cartridge together but also may be used for inserting and securing the parts in place within the head housing of a dental handpiece.

Abstract: A dental handpiece having a rotor housing with a chamber, a rotor within the chamber, and an improved spring grip chuck. The chamber has upper and lower openings coaxial therewith, the rotor has a bore aligned with the openings, and the chuck is received within the bore. The chuck is fixed to the bore and has a plurality of tapered spring jaws at its upper end which normally slope inwardly for frictionally contacting and holding a dental bur. The upper end of the bore is provided with a pusher nut which is accessible by means of a suitable wrench through the upper opening in the housing and which is adjustable for engaging and forcing open the jaws to permit removal and replacement of the bur.

Abstract: A hand-held pressurized fluid powered audible alarm includes a housing in which is mounted a pressurized container having a deflection responsive valve and outlet member projecting therefrom. A horn body is mounted on and in fluid communication with the member and a spring loaded plunger carried by the housing is provided to contact and displace the horn body thereby deflecting the member to supply pressurized fluid for sounding the alarm. The plunger is normally retained spaced from the alarm by a removeable pin passing transversely through the plunger shaft. A ring coupled to the pin is pulled to rapidly remove the pin and irreversibly activate the alarm.