Abstract: A fastener installation head having a reciprocating plunger receiving fasteners through a transverse fastener passage from a feed means and a fastener sensor means located within the fastener passage sensing the presence or absence of fasteners in the fastener passage ready for installation. The fastener sensor means includes an electrical switch which may be interconnected to the plunger activation circuit, opening the circuit and stopping the plunger when a fastener is not ready for installation.

Abstract: A fastener installation head having a nut receiving passage, a transverse plunger passage, a plunger reciprocating in the plunger passage through the intersection of the passages and a guide means for the nuts in the plunger passage. The guide means includes a pair of parallel rails generally in the plane of the nut supporting surface of the nut passage, supporting a nut beneath the plunger. The rails are resiliently biased to support the nut until impact by the plunger. Further, a resilient pad parallel to the reciprocating axis of the plunger is provided to guide the nut through the plunger passage.

Abstract: A fastener installation head having a nut receiving passage, a transverse plunger passage having a reciprocating plunger therein, a feed means feeding nuts from the nut passage to the plunger passage and a stop means preventing nuts from entering the plunger passage except upon actuation of the feed means. The stop means comprising two parallel cylindrical posts located on opposite sides of the nut passage at the intersection of the passages. The cylindrical posts being resiliently biased into the fastener receiving passage and normally preventing fasteners from entering the plunger passage except upon actuation of the feed means.

Abstract: A fastener installation head having a first passage receiving fasteners, a second transverse passage having a reciprocating plunger, a feed means feeding fasteners from the first passage to the second passage, beneath the plunger, during each downward stroke of the plunger and a stop means preventing a fastener from being fed into the second plunger passage except during the downward stroke of the plunger. The stop means comprising a stop lever pivotally connected to the housing within the plunger passage and the plunger having camming surfaces rotating the stop lever into and out of blocking engagement with the first fastener receiving passage. In the disclosed embodiment, a nut entering the plunger passage will cam the stop out of blocking relation upon actuation of the plunger.