Showing papers on "Compliant mechanism published in 1994"

Reliability-Based Optimal Design of a Bistable Compliant Mechanism

Abstract: Compliant mechanisms obtain at least some of their motion from the deflection of their flexible members. Advantages of such mechanisms include the reduction of manufacturing and assembly cost and time. Bistable mechanisms are particularly useful in applications where two stable equilibrium positions are required, such as switches, gates, and closures. Fatigue is a major concern in many compliant mechanisms due to the cyclic stresses induced on the flexible members. In this paper, a method for the probabilistic design of a bistable compliant slider-crank mechanism is proposed. Link lengths, material properties, and cross-section dimensions are taken as random variables. Probabilistic constraints on the maximum and minimum required input torque, location of stable equilibrium position, and overall size are included. The objective function is the maximization of the mechanism reliability in fatigue. Several design studies are performed to gain further insight into the nature of the problem.

Development of Force-Deflection Relationships for Compliant Mechanisms

Abstract: An arcuate escalator system having a readily fabricated and reliable construction is provided that also had advantageous esthetic aspects. In a specific example, the escalator is of helical configuration, arranged around a central axis. Tapered step segments meeting all established safety standards for size, configuration and entry and exit paths are advanced along the helical path in the desired direction. In the return path, the step segments turn through small radii of curvature into and out of an intermediate substantially linear portion, for which purpose they may be tilted and partially nested relative to each other. The principal return path is the linear portion of the path, in this example, and passes through a center column around which the helical structure is arranged. The drive mechanism comprises a guided chain drive having both lateral and vertical freedom of movement, and coupled to the step elements by pivotally connected step links. Guide means for the step elements and the chain drive system control the inclination and curvature of the path. Radial forces generated during movement of the system are absorbed by a roller guide system along the chain drive.