Some Elementary Projective Properties of the Four-Bar Linkage

1973 ◽  
Vol 95 (3) ◽  
pp. 721-724
Author(s):  
J. S. Marquez ◽  
D. P. Adams
Keyword(s):  
Practical Application ◽  
Connecting Rod ◽  
Complete Quadrilateral ◽  
Four Bar Linkage

The four-bar linkage defines a complete quadrilateral—a figure with extensive elementary projective properties. The undertaking is to search out and discover evidences or indicia of projective interrelationships in the geometry of the four-bar, such as concurrencies of lines, collineations of points, constancies of cross-ratios, harmonic divisions, tangencies of lines and curves, and others, toward the practical application of such properties in four-bar motion. Several of these have indeed been discovered and proved, each worth-while in its own right and each expressible as an instantaneous projective relationship between members of a simply-defined family of linkages. The most startling and applicable of the properties is the collineation of the centers of the inflection circles of the connecting-rod motions of the defined family.

Synthesis of the four-bar linkage as path generation by choosing the shape of the connecting rod

2020 ◽  
Vol 234 (13) ◽  
pp. 2643-2652 ◽  
Author(s):  
SM Varedi-Koulaei ◽  
H Rezagholizadeh
Keyword(s):  
Analytical Solution ◽  
Nonlinear Equations ◽  
Linear Equations ◽  
Solution Process ◽  
Current Method ◽  
Path Generation ◽  
Connecting Rod ◽  
Complicated Process ◽  
Four Bar Linkage ◽  
Analytical Synthesis

This paper presents a method for path generation synthesis of a four-bar linkage that includes both graphical and analytical synthesis and both cases of with and without prescribed timing. The advantage of the proposed method over available techniques is that it is easier and does not need the complicated process (especially in graphical case). In an analytical solution, this method needs the solution of the linear equations, unlike the previous methods, in that they have required the solution of the nonlinear equations. Moreover, in the current method, one can choose the shape of the coupler, while, in other methods, the shape of the coupler is the result of the solution process. The proposed algorithm can be used for path generation synthesizing of a four-bar linkage for three precision points.

Study of Forward Connecting Rod Combined Lifting Mechanism Based on Linear Transformation and Vector Algebra

2012 ◽  
Vol 155-156 ◽  
pp. 505-508
Author(s):  
Ming Qing Wu
Keyword(s):  
Mathematical Model ◽  
Rigid Body ◽  
Linear Transformation ◽  
Plane Motion ◽  
Connecting Rod ◽  
Vector Algebra ◽  
Lift Mechanism ◽  
Four Bar Linkage ◽  
The Mathematical Model

By adopting the method of block analysis,the paper analyzes and calculates the forward connecting rod combined lift mechanism by broking up it into a four-bar linkage and the plane motion of an arm triangle rigid body, constructs the kinematic equations of four-bar linkage and arm triangle and the static equations of four-bar linkage based on linear transformation and vector algebra and establishes the mathematical model of lift mechanism based on linear transformation and vector algebra.

scholarly journals DEVELOPMENT AND APPLICATION OF A COMPUTER PROGRAM FOR FOUR-BAR LINKAGE AND SLIDER-CRANK MECHANISMS

2020 ◽  
Vol 26 (3) ◽  
pp. 28-38
Author(s):  
OLADEJO KOLAWOLE ADESOLA ◽  
ADEKUNLE NURUDEEN OLATUNDE ◽  
ADETAN DARE ◽  
ABU RAHAMAN ◽  
ORIOLOWO KOLAWOLE TAOFIK
Keyword(s):  
Angular Acceleration ◽  
Visual Basic ◽  
Linear Displacement ◽  
Connecting Rod ◽  
Software Application ◽  
Crank Angle ◽  
Mathematical Problems ◽  
Angular Velocities ◽  
Four Bar Linkage ◽  
Crank Mechanism

Complex mathematical problems have been solved with the aid of software application to obtain reliable results. The positional kinematic analysis of a slider crank mechanism involves computation of the motion parameters: linear displacement, velocity and acceleration of the slider; and angular velocity and angular acceleration of the connecting rod for every 300 variation of the crank angle. This study aimed to develop a customized software which can be used to efficiently analyse a given design of a four-bar and a slider-crank mechanisms. A program was written using VB (Visual Basic) programming language for the equations of angular velocities and angular acceleration of the coupler and follower for the four-bar linkage and the linear velocity and acceleration of the piston for the slider crank mechanism. The program was tested with different parameters for the mechanisms and the solutions compared with the results from manual calculations. The findings revealed that there were no differences (p ≤ 0.05) between the results using the program and manual calculations, which imply the accuracy of the program. It can be concluded that the program could be used to solve problems of four- bar linkage and slider-crank mechanisms.

scholarly journals Multi-objective Optimization Design of a Heavy Duty Folding Mechanism and Self-discharging Equipment Development

2020 ◽  
Author(s):  
Lairong Yin ◽  
Chong-Xiang Li ◽  
Juan Huang ◽  
Bo Wen ◽  
Jin-Hang Wang
Keyword(s):  
Optimization Design ◽  
Technical Problem ◽  
Angular Acceleration ◽  
Multi Objective Optimization ◽  
Practical Application ◽  
Connecting Rod ◽  
Heavy Load ◽  
Multi Objective ◽  
Adams Software ◽  
Equipment Development

Abstract In this paper, we investigated the technical problem of the recovery of overlength and heavy load conveying booms of self-unloading ships. A method of folding the conveying boom with a hydraulic-four-bar mechanism is presented, and by using a mathematical model for the optimization of folding speed stationary with ADAMS software, the optimization data and results were obtained. The multi-objective optimization index is introduced, and the multi-objective optimization problem is discussed. The results of the multi-objective optimization showed that parameters such as angular velocity and the change of angular acceleration of the conveyor boom were optimized. The paper has manufactured the connecting rod mechanism, and developed the self-discharging folding conveyance equipment. Through practical application, we determined that the developed folding conveying equipment had the advantages of smooth movement and high folding efficiency.

Affect the Linkage Vibration Characteristic Parameter Analysis and Research

2014 ◽  
Vol 971-973 ◽  
pp. 341-344
Author(s):  
Meng Jiang Chai
Keyword(s):  
Dynamic Response ◽  
Fatigue Failure ◽  
High Speed ◽  
Basic Characteristic ◽  
Characteristic Parameter ◽  
Parameter Analysis ◽  
Vibration Characteristic ◽  
Connecting Rod ◽  
Complex Motion ◽  
Four Bar Linkage

connecting rod mechanism can realize complex motion law, but under the condition of running at high speed, institutions, the elastic dynamic response of not only make the institutions of trajectory deviation, also can cause fatigue failure. In this paper, we study the basic characteristic of the four-bar linkage, affect the motion law of several parameters were analyzed.

scholarly journals New design of grab mechanism in plastic glove machine

2018 ◽  
Vol 169 ◽  
pp. 01014
Author(s):  
Wei-Chun Hsu ◽  
Ming-Jin Jiang ◽  
Gui-Liang Liu
Keyword(s):  
Main Part ◽  
Path Tracking ◽  
The Other ◽  
Connecting Rod ◽  
Position Analysis ◽  
Plastic Bags ◽  
New Type ◽  
Four Bar Linkage

The aim of this study is to design a new type of grab mechanism for plastic bags machine in order to tear apart the plastic gloves from the plastic bags and stack them into a pile automatically. A grab mechanism with four bar linkage is developed and the main part of the grab mechanism is the clip which will pick up the plastic gloves and drag them to the other side. After a distance of drag, the clip will drop the plastic gloves to the collecting plate. The clips are fixed on the connecting rod of the four-bar linkage and the path of the clip can be traced by the position analysis of the four bar linkage. The path of the clip can be tracked by determination of the four links’ lengths. This path tracking will be one of the advantages of this new mechanism because it provides the different drag distance to grab difference size of plastic gloves by simply adjusting the lengths of four links.

Analysis of Rod Length Change in the Rapier Weft Insertion Mechanism Transmitted by Spatial Four Bars

2011 ◽  
Vol 382 ◽  
pp. 195-199
Author(s):  
Yong Kang Xu ◽  
Lei Zhang ◽  
Xiao Ye Pan ◽  
Shi Fu Xu ◽  
Bo Hong Wang
Keyword(s):  
Characteristic Curve ◽  
Length Change ◽  
Connecting Rod ◽  
Length Range ◽  
Insertion Mechanism ◽  
Motion Characteristic ◽  
Length Changes ◽  
Four Bar Linkage ◽  
The Impact ◽  
Matlab Programming

In order to analysis kinematics characteristic of space four bar linkage weft insertion mechanism and the influence on movement law by connecting rod length change, mathematical models of every parts of the mechanism were proposed by the method of analysis, and through MATLAB programming, motion curves were obtained. The length range of connecting rod and rocker, and the impact of changes in length were also studied, and some corresponding conclusions were drawn. The motion characteristic curve of it has been in accord with the weft inserting requirements. The study of kinematics, especially the discussion of connecting rod length changes will pave the way for the further study of dynamics.

Synthesis of Four-Bar Linkage Function Generators by Means of Equations of Motion

1965 ◽  
Vol 87 (2) ◽  
pp. 170-176 ◽  
Author(s):  
C. K. Wojcik
Keyword(s):  
Equations Of Motion ◽  
Angular Acceleration ◽  
Input Output ◽  
Connecting Rod ◽  
Function Generator ◽  
Function Generation ◽  
Function Generators ◽  
Two Parameters ◽  
Four Bar Linkage ◽  
Selection Of

The function generation method presented in this paper is based on consideration of the equations of motion of a four-bar linkage with an assumed input of θ˙1 = 1 rad/sec. For a specified input-output relationship, the task of synthesizing an appropriate four-bar linkage is reduced by this method to a problem of selecting two parameters: θ˙2—the angular velocity and θ¨2—the angular acceleration of the connecting rod. The selection of these parameters is governed by certain conditions imposed on the performance of the four-bar linkage function generator. Using this method, two specific problems are solved and discussed in detail.

Progress In The Practical Application Of Automated Image Analysis To Tem Negatives

1977 ◽  
Vol 35 ◽  
pp. 214-217
Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly
Keyword(s):  
Image Analysis ◽  
Image Quality ◽  
Exposure Time ◽  
Image Contrast ◽  
Automated Image Analysis ◽  
Practical Application ◽  
Factors Affecting ◽  
High Image Quality ◽  
Qualitative Evidence ◽  
Comprehensive Study

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.

Fifth Edition: the New Standard

2000 ◽  
Vol 5 (6) ◽  
pp. 1-7
Author(s):  
Christopher R. Brigham ◽  
James B. Talmage ◽  
Leon H. Ensalada
Keyword(s):  
Musculoskeletal System ◽  
Medical Information ◽  
Objective Assessment ◽  
Scientific Data ◽  
Practical Application ◽  
Fourth Edition ◽  
Appropriate Use ◽  
Medical Evaluation ◽  
Single Set

Abstract The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fifth Edition, is available and includes numerous changes that will affect both evaluators who and systems that use the AMA Guides. The Fifth Edition is nearly twice the size of its predecessor (613 pages vs 339 pages) and contains three additional chapters (the musculoskeletal system now is split into three chapters and the cardiovascular system into two). Table 1 shows how chapters in the Fifth Edition were reorganized from the Fourth Edition. In addition, each of the chapters is presented in a consistent format, as shown in Table 2. This article and subsequent issues of The Guides Newsletter will examine these changes, and the present discussion focuses on major revisions, particularly those in the first two chapters. (See Table 3 for a summary of the revisions to the musculoskeletal and pain chapters.) Chapter 1, Philosophy, Purpose, and Appropriate Use of the AMA Guides, emphasizes objective assessment necessitating a medical evaluation. Most impairment percentages in the Fifth Edition are unchanged from the Fourth because the majority of ratings currently are accepted, there is limited scientific data to support changes, and ratings should not be changed arbitrarily. Chapter 2, Practical Application of the AMA Guides, describes how to use the AMA Guides for consistent and reliable acquisition, analysis, communication, and utilization of medical information through a single set of standards.

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