Fitting for structural pipe

Claim 1

A concealed fitting for connection to a structural pipe having an open internal cavity at its end, comprising: a body having means associated therewith to facilitate securing said body to a structural member, said body having a recess therein communicating with the exterior of said body, a pair of parallel arms extending outwardly from said body on opposite sides of said recess, said arms having outer peripheral surfaces configured to collectively snugly fit within said open internal cavity of a structural pipe to which said fitting is to be connected, said arms being spaced from each other to define a slot therebetween connecting with said recess, a unitary locking element located in said slot between said arms, means mounting said locking element for pivotal movement on an axis intersecting said arms, said locking element having first and second oppositely directed pipe-clamping projections moveable between inner and outer positions in which said pipe-clamping projections extend from said slot radially inwardly and outwardly of said outer peripheral arm surfaces, respectively, said locking element having a third surface located within said recess, and an actuator moveable in locking and unlocking directions having an inner end extending into said recess and an outer end accessible exteriorly of said body when said arms are positioned within said open internal cavity of a structural pipe, said actuator inner end engaging said third surface of said locking element for pivoting, when said outer end of said actuator is moved in said locking direction, said locking element first and second projections to their outer positions to clamp a structural pipe in which open internal cavity said arms are fitted, said actuator inner end permitting said locking element first and second projections to move to their inner position to release said structural pipe when said actuator outer end is moved in said unlocking direction.