Abstract: A control system for an air driven drill is described, wherein the control system is of the kind that provides a feed stroke to a drill bit. The system comprises an interrupt line so that compressed air fed to a feed chamber is also fed to a clamp chamber whereby the unbalanced force on the feed piston becomes balanced so as to stop the feed stroke. An adjustable frequency generator is provided to impose a pulsating pressure variation in an air pressure supply. During a feed stroke under which compressed air is fed to the feed chamber, air fed to the clamp chamber via the interrupt line is caused by the adjustable frequency generator to have a pulsating pressure, so that the feed stroke is caused to be stopped for a first period, then resumed for a second period, to provide a periodically interrupted feed stroke.

Abstract: A control system for an air driven drill is described, wherein the control system is of the kind that provides a feed stroke to a drill bit. The system comprises an interrupt line so that compressed air fed to a feed chamber is also fed to a clamp chamber whereby the unbalanced force on the feed piston becomes balanced so as to stop the feed stroke. An adjustable frequency generator is provided to impose a pulsating pressure variation in an air pressure supply. During a feed stroke under which compressed air is fed to the feed chamber, air fed to the clamp chamber via the interrupt line is caused by the adjustable frequency generator to have a pulsating pressure, so that the feed stroke is caused to be stopped for a first period, then resumed for a second period, to provide a periodically interrupted feed stroke.

Abstract: A pneumatically operated rivet squeezer is described, having features that allow for the miniaturization of a squeezer to a size smaller than portable rivet squeezers presently available. A first feature of the invention is that a return spring is accommodated within the squeezer housing by embedding the spring diametrically partially within a cavity in an internal wall of the housing and diametrically partially within a cavity in a jaw of the squeezer. A second feature of the invention contributing to miniaturization is that the squeezer utilizes a wedge having a very high mechanical advantage during the final stage of squeezing action, and a novel two curve surface for applying force to arms of the squeezer.