Wedge (mechanical device)

About: Wedge (mechanical device) is a research topic. Over the lifetime, 12897 publications have been published within this topic receiving 75738 citations.

A Guide to First-Passage Processes

Abstract: Preface Errata 1. First-passage fundamentals 2. First passage in an interval 3. Semi-infinite system 4. Illustrations of first passage in simple geometries 5. Fractal and nonfractal networks 6. Systems with spherical symmetry 7. Wedge domains 8. Applications to simple reactions References Index.

Surgical stapling device with multiple stacked actuator wedge cams for driving staple drivers

Abstract: A surgical stapling device (10,800) comprising an end effector (12,812) and a plurality of stacked actuatable wedge band sets (710,712,714,822,824,826). The end effector comprises an anvil (18,810) having a staple forming surface (202) and a staple cartridge (300,809) facing the staple forming surface of the anvil. The staple cartridge comprises a plurality of staples (222) and a plurality of staple drivers (330a,330b,370a,370b,1012,1014) moveable supportable within the staple cartridge. Each staple driver is in contact with one of the staples and configured such that when the staple drivers are actuated, the staple drivers drive the staples through the staple cartridge so that the staples are formed against the staple forming surface of the anvil. Each stacked wedge band set comprises at least two different-level wedge bands (720,722) for axially traversing the end effector. Each wedge band comprises a wedge cam (709) at its distal end for driving certain ones of the staple drivers when the wedge band is actuated. A first of the two wedge bands in the stacks rides on a second of the two wedge bands in the stacks such that the staple drivers are driven in successive stages by the at least two wedge bands when the wedge bands are driven in succession. The cumulative height of a first of the plurality of stacked wedge band sets is less than a cumulative height of a second of the plurality of stacked wedge band sets.

Endoscopic surgical clip applier

Abstract: A surgical clip applying apparatus is disclosed which has a handle portion, a body extending distally from the handle portion defining a longitudinal axis and a number of surgical clips disposed within the body. The apparatus has a movable member biased in the housing adjacent the wedge plate. An actuator longitudinally advances the wedge plate a predetermined distance to a distal most position. The wedge plate has an end being disposed between first and second jaw portions at the distal most position. The wedge plate end is configured to maintain the jaw assembly in the spaced apart position during loading of the surgical clip and the wedge plate end reduces torque and external forces on the jaw assembly during the loading. The movable member holds the wedge plate in the distal most position during the loading and the movable member is deflected at a conclusion of the loading. The movable member releases the wedge plate upon deflection. The movable member allows a longitudinal proximal retraction of the wedge plate from the distal most position.

A Mechanism for the Control of Crack Propagation in All-Brittle Systems

Abstract: The stress distribution close to the tip of a crack which has a finite tip radius and which is being opened either by means of a remotely applied tension field σ y , 0 or by means of a concentrated force (e. g. a wedge driven into the crack) has been computed. It is shown that there exist tensile stresses (σ x ) parallel to the plane of the crack and ahead of the crack tip. The maximum value of the tension σ x is an approximately constant fraction (~ 1/5) of the peak stress concentration σ y , max . which usually causes crack propagation. Inside a brittle solid, if a plane of weakness or potential cleavage is present and is roughly normal to the plane of the original crack, this interface may break and produce a secondary crack in such a manner as to interfere with the progress of the primary crack. If the ratio of the adhesive strength of the interface to the general cohesive strength of the solid is in the right range large increases in the strength and toughness of otherwise brittle solids may result.

On optimum design in fluid mechanics

Abstract: In this paper, the change in energy dissipation due to a small hump on a body in a uniform steady flow is calculated. The result is used in conjunction with the variational methods of optimal control to obtain the optimality conditions for four minimum-drag problems of fluid mechanics. These conditions imply that the unit-area profile of smallest drag has a front end shaped like a wedge of angle 90°.