Trap design for vibratory bowl feeders

Abstract

The vibratory bowl feeder is the oldest and still most common approach to the automated feeding (orienting) of industrial parts. In this paper we consider a class of vibratory bowl filters that can be described by removing polygonal sections from the track; we refer to this class of filters as traps.For an n-sided polygonal part and an m-sided polygonal trap, we give an O(n 2 m log n) algorithm to decide whether the part in a specific orientation will safely move across the trap or will fall through the trap and thus be filtered out. For an n-sided convex polygonal part and m-sided convex polygonal trap, this bound is improved to O((n + m) log n).Furthermore, we show how to design various trap shapes, ranging from simple traps to general polygons which will filter out all but one of the different stable orientations of a given part. Although the run times of our design algorithms are exponential in the number of trap parameters, many industrial part feeders use few-parameter traps (balconies, canyons, slots); in these cases the running times of our algorithms range from linear to low degree polynomial.

On the design of traps for feeding 3D parts on vibratory tracks

“…The availability of all solutions, as output by our complete design algorithm, allows for the selection of trap designs with good deflection abilities as a post-processing phase. Except for the one-parameter balcony trap [6], we surmise that the class of V-traps generally provides stronger deflection capabilities than previously proposed classes of traps [1,6,17]; further research is needed to confirm this intuition.…”

“…Geometric analysis tools have been developed that help designers visualize the configuration space of a given combination of part and bowl layout [12]. Research to single reorientation and rejection mechanisms has been focused at certain classes of simple parts [9,10] and, for a more general class of parts, at the design of traps [1,6,17]-traps are devices constructed by removing sections of the track. A common characteristic of the general solutions in the latter category is that the resulting (trap) designs only apply to two-dimensional parts.…”

“…Extending prior work on traps [1,6,17] for 2D parts, we propose a class of traps for feeding 3D parts that is inspired by similar devices from the practice of vibratory feeder design [9,10]. We believe that this class of what we shall refer to as V-traps is rich enough to feed a broad class of 3D parts yet simple and structured enough to facilitate efficient automated design.…”

Internet-Based CAD Tool for Design of Gripper Jaws

“…Jaws will align the user's part from an initial resting orientation to a desired final orientation as the gripper is closed. [3] describe an online CAD tool for design of traps for the tracks of vibratory bowl feeders. Smith et al [15] develop a Java applet to compute and rank all pairs of paralleljaw grip points for polygonal parts.…”

“…No jaw design exists if v 3 is within the boundary of the critical area. The boundary is represented by the intersection of H and z 3 . We consider each term in H, and want to prove that H is determined by So the boundary can be determined by: …”