Captive screw and method for installing same
A captive fastener and method of use is disclosed wherein the screw is comprised of a head and shank, and where the shank includes a radial counter bore that retains a spring biased pin. The spring may bear against a plug in the counter bore or the shank inner wall, and biases the pin outward such that it extends outside of the shank in the absence of a compressive force. The captive screw is inserted through a top panel by tilting the screw at the opening of the panel such that the pin is pushed inward into the channel formed by the counter bore (against the force of the spring). Once the pin is recessed in the screw, the screw is passed through the panel opening until the shank emerges on the other side. Once the shank pushes through the panel, the pin will emerge under the biasing of the spring to extend outward of the shank in the radial direction. The pin thus prevents the screw from disengaging with the panel. A holdout fork is applied to the shank to anchor the screw at the retracted position, which keeps the screw up right against the surface of the panel.
1. A captive fastener system comprising a fork, and a fastener having a head, neck, and threaded shank, the captive fastener system comprising:
a first bore near the distal end of the shank and a counter bore coaxial thereto;
a plug occluding the counter bore;
a coil spring disposed within the counter bore having a longitudinal axis that is aligned with axes of the bore and counter bore;
a pin disposed within the bore and having a pinhead configured to prevent the pin from escaping the first bore, a distal tip of said pin extendable through the first bore against a biasing of the spring and wherein a length of the pin allows the pin to be fully retractable into the first bore;
a holdout fork having a base and a pair of spaced apart tines separated by a distance equal to an outer diameter the threaded shank, the base including an angled tab that extends obliquely with the spaced apart tines;
wherein an inwardly directed force on the pin compresses the spring and allows the pin to recede into the bore; and
wherein the hold-out fork is placed on the shank such that the tines engage the shank therebetween to hold the shank while the pin is retracted in a body to be fastened.
2. The captive fastener system of claim 1 , wherein the hold-out fork angled tab extends obliquely with the spaced apart tines at an angle between one hundred thirty degrees and one hundred forty degrees.