Fastener inspection system and method

#The invention relates to optical inspection of objects to determine whether they meet required manufacturing specifications, and in particular to the optical inspection of fasteners.

#It is known to optically inspect manufactured items for defects that would render the item unusable, such as by combining a fastener inspection system with a single camera. The inspection of fasteners may include examining threaded fasteners to ensure that the threaded portion is correctly formed, that the fastener head is correctly formed, that the junction of the head and shank is correctly formed, that the shank is correctly formed at the terminal end, and other suitable examinations.

#One drawback to prior methods and systems is that the optical inspection software must be able to match the object against a library of acceptable objects regardless of its orientation and lighting, and this must be done in a rapid manner. While some of these problems can be solved by initially orienting the object in only one position and then moving it to other pre-determined positions, the recognition software must still track the object and recognise it once it has reached the new orientation. This process requires a computationally intensive operation that can be the limiting factor in the production and quality control of the fasteners.

#FIG. 1 is a diagram an inspection station in accordance with an exemplary embodiment of the present invention;

#FIG. 2 is a diagram of an inspection station showing a horizontal vision system in accordance with an exemplary embodiment of the present invention;

#FIG. 3 is a diagram of an inspection station showing a vertical vision system in accordance with an exemplary embodiment of the present invention;

#In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawing figures might not be to scale, and certain components can be shown in generalized or schematic form and identified by commercial designations in the interest of clarity and conciseness.

#FIG. 1 is a diagram an inspection station 100 in accordance with an exemplary embodiment of the present invention. Inspection station 100 allows the top dimension of fasteners to be inspected, with compensation for variations in surface finish.

#Inspection station 100 includes base 101 having on it a rotating turntable 102. Singulating feed mechanism 106 provides fasteners 104 to rotating turntable 102, and the fasteners 104 are fed into fastener retaining slots 103 by centrifugal force, where they can be inspected by inspection system 700 (not explicitly shown) using image data generated by horizontal vision system 200, vertical vision system 300, and other suitable systems. Inspection system 700 generates rejection data, which causes rejection mechanism 400 to actuate and to eject fasteners 104 that do not meet inspection criteria. If rejection data is not generated, the fasteners 104 are accepted at an acceptance position that includes stationary wiper 115, which removes the acceptable fasteners 104 that remain after the rejected fasteners 104 have been removed.