Sealant applicator apparatus for automatic riveting machines and the like

Abstract

A sealant applicator apparatus is disclosed of a form adapted for incorporation in automatic riveting machines and the like as one of the positionally indexed, sequentially operated tools in the machine along with the usual drill, countersink tool and riveter. Mounted and actuated under controlled pressure in position to pick up a bead of sealant from a supply source during one of the indexed functions of the riveter machine, the sealant applicator later in the sequence is automatically positioned over the countersunk hole and actuated under controlled pressure to deposit the bead of sealant on the countersink surface as a step preceding insertion and bucking of the rivet. An air motor rotating the flexibly deformable, rounded sealant applicator tip is itself mounted as a reciprocative piston in a support cylinder into which pressurized air is introduced so as to advance the applicator tip toward the sealant source and alternately toward the workpiece, and, in the process of each such advancement, to initiate rotational operation of the air motor. The pneumatic pressure advancing the air motor in the cylinder acts against a return spring in a balance of forces that can be adjusted relatively so as to exert a precisely controlled amount of pressure of the applicator tip against the sealant source bed or mandrel so as to pick up a bead of sealant, and also thereafter against the countersink surface so as to deposit the bead on the countersink surface. Rotation of the applicator tip during acquisition and separation of a sealant bead from the supply source, and also during deposit of that bead on the countersink surface followed by separation of the applicator tip therefrom, prevents smearing and stringing of the sealant. By stopping or reducing tip rotation in the interim, centrifugal force effects are prevented from impairing the original shape and position of the sealant bead on the applicator tip.