Abstract: One of two elongate tubular frame members to be removably connected is telescoped over, and frictionally and also latchably removably secured to the intervening connector structure. The connector structure comprises a conventional rigid body component of inverted U-shaped configuration including apertured horizontal wall and two vertical flanking-walls, for respective broad frictional engagements with the apertured top-panel and the two vertical panels of the surrounding tubular frame member. Departing from the prior art, the connector structure herein comprises a J-shaped spring means, the longerleg extending along the inner surface of the connector apertured horizontal wall and being provided with an upwardly extending locking projection surrounded by said wall aperture, and the shorterleg extending below the bottom-plane of the body flanking-walls.