Abstract: A filter indicator system for indicating when air flow through a filter is restricted includes an indicator mounted in a filter assembly downstream of the filter. The indicator includes a housing having a central space, a side wall, an end wall, an end inlet in the end wall, and a side outlet. A pop-up member is located in the central space and includes a signal portion which extends adjacent the end inlet. A moving device is then used for moving the pop-up member between a non-signalling position where the signal member does not extend noticeably through the end inlet and a signalling position where the signal portion extends noticeably through the end inlet.

Abstract: A pneumatically operated percussive dental extractor includes a main body having a central longitudinal chamber. A replaceable hook member is attached to the distal end of the main body. Mounted in the longitudinal chamber at a proximal end thereof is an anvil. Reciprocally mounted in the longitudinal chamber for movement from a distal end thereof to engagement with the anvil is a piston. A driving device selectively drives the piston pneumatically from the distal end of the chamber into percussive engagement with the anvil. A return device automatically returns the piston from engagement with the anvil to the distal end of the chamber. The driving device includes a coupling located at the proximal end of the main body for connecting the driving device to a source of pneumatic pressure and a trigger device for selectively connecting the source of pneumatic pressure to the distal end of the chamber.