Geometric Conditions for the Satisfaction of Order in Four Position Synthesis of Four-Bar Linkages

1992 ◽  
Author(s):  
John A. Mirth
Keyword(s):  
Type A ◽  
Computer Programs ◽  
Order Condition ◽  
Order Problem ◽  
Geometric Characteristics ◽  
Geometric Conditions ◽  
Linkage Design ◽  
Correct Sequence ◽  
Pass Through ◽  
Position Synthesis

Abstract A mechanism that cannot pass through all precision positions in the correct sequence is said to violate the order condition. This paper establishes the order requirements for the precision position synthesis of all Grashof and non-Grashof four-bar linkages. These order requirements are based on three geometric characteristics of the four-bar mechanism: the angle of one of the rotating links that is attached to the ground link; the limits that the entire mechanism imposes on this rotating link; and the dyad configurations for the dyad that is opposite the ground pivot of this link. The results improve upon traditional discussions of the order problem by including all four-bar linkages, rather than just those of a specified Grashof type. A table summarizes the results in a form that allows for their implementation into computer programs for linkage design and analysis.

Two Precision Position Synthesis of Planar Linkages With Positional Rectification

1996 ◽  
Author(s):  
John A. Mirth
Keyword(s):  
Numerical Algorithms ◽  
All Solutions ◽  
Pass Through ◽  
Planar Linkages ◽  
Position Synthesis ◽  
Exact Positions

Abstract Precision position synthesis is used to generate planar linkages that pass through two exact positions and an additional number of approximate positions. The approximate positions provide a means of rectifying the solution linkages such that all solutions presented are more likely to describe a motion that remains within acceptable positional bounds. The rectification method involves the development of three different numerical algorithms that may be applied to a particular step in the dyad/triad method of precision position synthesis. The three algorithms presented can be applied in a variety of combinations to allow for the synthesis of both simple (four-bar) and complex (multiloop) planar linkages.

Four-Bar Linkage Synthesis Methods for Two Precision Positions Combined With N Quasi-Positions

1995 ◽  
Author(s):  
John A. Mirth
Keyword(s):  
Synthesis Method ◽  
Synthesis Methods ◽  
Bounded Motion ◽  
Transmission Angle ◽  
Pass Through ◽  
Position Synthesis ◽  
Four Bar Linkage ◽  
Exact Positions ◽  
Linkage Synthesis

Abstract Mechanisms seldom need to pass through more than one or two exact positions. The method of quasi-position synthesis combines a number of approximate or “quasi” positions with two exact positions to design four-bar linkages that will produce a specified, bounded motion. Quasi-position synthesis allows for the optimization of some linkage characteristic (such as link lengths or transmission angles) by using the three variables that describe a single quasi-position. Procedures for circuit and transmission angle rectification are also easily incorporated into the quasi-position synthesis method.

Collision-Free Trajectory Generation for Waterway Surfaces of a PDC Drill Bit

2011 ◽  
Vol 84-85 ◽  
pp. 194-198
Author(s):  
Xu Bing Chen ◽  
Yang Song ◽  
Han Xin Chen
Keyword(s):  
Critical Points ◽  
Parametric Method ◽  
Trajectory Generation ◽  
Interpolation Formula ◽  
Linear Interpolation ◽  
Drill Bit ◽  
Geometric Characteristics ◽  
Drill Bits ◽  
Pass Through ◽  
Constraint Surface

After describing geometric characteristics of a PDC drill bit’s waterway surfaces, an approach for collision-free trajectory generation are proposed. The trajectory is planned by an iso-parametric method firstly, while the tool orientations are determined by visibility cones, which are the bounded regions between the opposite surfaces of neighboring blade wing pairs. Tool orientations are produced by calculations of critical points and interpolations between them. Furthermore, the criterion of whether tool orientations pass through the constraint surface and the linear interpolation formula of tool orientations are given. The research has created conditions for the success machining of PDC drill bits, and related machining enterprises of impellers and propellers will also be benefited.

The Synthesis of Planar Linkages to Satisfy an Approximate Motion Specification

1993 ◽  
Author(s):  
John A. Mirth
Keyword(s):  
Design Space ◽  
Accurate Position ◽  
Solution Region ◽  
Pass Through ◽  
Position Problem ◽  
The Individual ◽  
Planar Linkages ◽  
Position Synthesis ◽  
Individual Design ◽  
Complete Process

Abstract This paper introduces the method of quasi-precision position synthesis for planar linkages. A quasi-precision position is defined by an approximate region that the mechanism must pass through. The quasi-precision position problem specification generates an increased design region by not requiring the accurate position specification that is characteristic of optimization and precision position methods. The design space is generated by intersecting the individual design regions of different four position sets. Each four position set consists of three exact positions plus one quasi-precision position. The method allows for the use of any number of quasi-precision positions. The result of using quasi-precision positions is an increase in the available design space without violating the basic problem constraints. The increased solution region gives the designer a greater variety of choices while reducing the number of required design iterations. The complete process of quasi-precision position synthesis is presented through the use of an example.

Desain dan Uji Teknis Alat Pencetak dan Pemotong Amplang Secara Mekanis

2016 ◽  
Vol 8 (16) ◽  
pp. 95-103
Author(s):  
Jantri Sirait
Keyword(s):  
Performance Test ◽  
Cutting Tools ◽  
Type A ◽  
Conveyor Belt ◽  
Raw Material ◽  
Narrow Slit ◽  
Test Tool ◽  
Type C ◽  
Pass Through ◽  
And Performance

Has done manufacture printers and cutting tools Amplang mechanically, the goal is to increase productivity and reduce the cost of production Amplang, so that productivity increases Amplang crackers. Method of making a tool implemented by means of data collection, design drawings, tool making and designing distance to the runway slicer blade, cutting kepisau feeder speed design, and conduct performance test tool. The working principle is a tool designed extruder screw type, where the raw material is inserted into the funnel at one end of the extruder. By turning the screw extruder, the materials will be driven forward pass through the narrow room, and eventually forced to go through a narrow slit in a certain form, so that the dough will be pushed out through the hole forming a conveyor belt which is directed upwards.Specifications printer and cutter tool Amplang the made; (1) the mount base with length, width, height (60,60,80) cm, (2) drive using an electric motor 0.25 Hp 1430 rpm rotation and to increase the driving force used gearbox with a ratio of round 1 : 10 were associated with vanbelt type A 45 cm diameter and use polly type C diameter of 19 cm. From the results of the operation of tools and performance test tool takes as long as 25 minutes to print and cut Amplang weighing 2 kg, while the manual labor it takes 1 hour 30 minutes with a workforce of one person.ABSTRAKTelah dilakukan pembuatan alat pencetak dan pemotong amplang secara mekanis, tujuannya adalah untuk meningkatkan hasil produksi amplang serta memperkecil biaya produksi, agar produktifitas kerupuk amplang meningkat. Metode pembuatan alat dilaksanakan dengan cara pengumpulan data, desain gambar, pembuatan alat serta mendesain jarak mata pisau ke landasan pengiris, mendesain kecepatan pengumpan kepisau potong,  dan melakukan uji unjuk kerja alat. Prinsip kerja alat yang dirancang adalah ekstruder tipe ulir, dimana bahan mentah dimasukkan kedalam corong disalah satu ujung ekstruder. Dengan berputarnya ulir ekstruder maka bahan-bahan tersebut akan terdorong kedepan melewati ruangan yang sempit, dan akhirnya dipaksakan untuk melalui celah sempit dalam bentuk tertentu, sehingga adonan akan terdorong keluar melalui lobang pembentuk yang diarahkan keatas belt konveyor. Spesifikasi alat pencetak dan pemotong amplang yang dibuat; (1) rangka dudukan dengan panjang, lebar, tinggi (60,60,80) cm, (2) penggerak menggunakan motor listrik 0,25 Hp putaran 1430 rpm dan untuk menambah tenaga penggerak dipergunakan gearbox dengan perbandingan putaran 1 : 10 yang dihubungkan dengan vanbelt type A diameter 45 cm dan menggunakan polly type C diameter 19 cm. Dari hasil pengoperasian alat dan uji unjuk kerja alat dibutuhkan waktu selama 25 menit untuk mencetak dan memotong amplang seberat 2 kg, sedangkan dengan tenaga manual dibutuhkan waktu 1 jam 30 menit dengan tenaga kerja satu orang.Kata kunci : alat pencetak dan pemotong amplang, secara mekanis, sistem ulir. 

Planar Linkage Synthesis for Function Generation Using Poles and Rotation Angles

2015 ◽  
Author(s):  
Ronald A. Zimmerman
Keyword(s):  
Analytical Solution ◽  
Graphical Solution ◽  
Function Generation ◽  
Design Time ◽  
Input And Output ◽  
Linkage Design ◽  
Pass Through ◽  
Solution Mechanism ◽  
Four Bar Linkage ◽  
Selection Of

Function Generation is a long standing linkage design problem. It is possible to design a planar four bar linkage whose input and output links will pass through seven coordinated positions. This paper discloses the first graphical solution to this problem. The approach is to consider the constraints imposed by the target positions on the linkage through the poles and rotation angles. This approach enables the designer to explore the range of possible solutions when fewer than seven positions are specified by dragging a fixed or moving pivot in the plane. The selection of free choices is made at the end of the process and the complete mechanism is visible when the choices are made. The constraints only need to be made once which eliminates the repetitive construction required by previous methods to consider multiple pivot locations. Since it is so easy to consider multiple pivot locations and the solution mechanism is visible, the required design time is greatly reduced. A corresponding analytical solution is also developed and solved based on the same constraints. This is a new analytical solution and is defined by a system of 20 nonlinear equations with 20 unknowns.

Methods for Improving the Knuckle Boom Capacity in Truck-Mounted Cranes

1976 ◽  
Vol 98 (4) ◽  
pp. 1183-1187
Author(s):  
B. N. Sridhar
Keyword(s):  
Test Data ◽  
Close Agreement ◽  
Moment Arm ◽  
Linkage Design ◽  
Position Synthesis ◽  
Four Bar Linkage ◽  
Constant Moment

Presented herein are two different concepts for improving the knuckle boom capacity of truck-mounted cranes. The first concept deals with an improved Planar four-bar linkage using the two-position synthesis, as well as with recommendations for optimizing the linkage. The linkage design employing the two-position synthesis was built as hardware with fairly close agreement between calculated and test data. The second concept is concerned with a constant moment-arm mechanism using a rack and pinion arrangement.

Planar Linkage Synthesis for Coupler Point Path Guidance Using Poles and Rotation Angles

2014 ◽  
Author(s):  
Ronald A. Zimmerman
Keyword(s):  
Analytical Solution ◽  
Nonlinear Equations ◽  
Design Problem ◽  
Graphical Solution ◽  
Design Time ◽  
Linkage Design ◽  
Pass Through ◽  
Solution Mechanism ◽  
Four Bar Linkage ◽  
Selection Of

Coupler point path guidance is a long standing linkage design problem. It is possible to design a four bar linkage with a coupler point that will pass through up to nine specified points. This paper discloses a new graphical solution to this problem. The approach is to consider the constraints imposed by the target points on the linkage through the poles and rotation angles. This approach enables the designer to explore the range of possible solutions when fewer than nine points are specified by dragging a fixed or moving pivot in the plane. The selection of free choices is made at the end of the process and the complete mechanism is visible when the choices are made. The constraints only need to be made once which eliminates the repetitive construction required by previous methods to consider multiple pivot locations. Since it is so easy to consider multiple pivot locations and the solution mechanism is always visible, the required design time is greatly reduced. A corresponding analytical solution is also developed and solved based on the same constraints. The analytical solution is defined by a system of 28 nonlinear equations with 28 unknowns.

“MKCIRCLES”: An Interactive Computer Graphics Design Tool to Solve the Generalized Three-Precision-Position Synthesis Problem

1994 ◽  
Author(s):  
Pi-Ming Cheng ◽  
Raed N. Rizq ◽  
Arthur G. Erdman
Keyword(s):  
Computer Graphics ◽  
Design Tool ◽  
Synthesis Problem ◽  
Path Generation ◽  
Motion Generation ◽  
Interactive Computer Graphics ◽  
Linkage Design ◽  
Planar Regions ◽  
Angular Displacements ◽  
Position Synthesis

Abstract A new interactive computer graphics program (MKCIRCLES) has been developed to solve the following three-precision-position dyad synthesis tasks: (i) motion generation, (ii) path generation with prescribed timing and (iii) a new solution strategy for (a) motion generation for a user-specified range of the prescribed-timing angular displacements, and (b) path generation with prescribed timing for a user-specified range of the rotations of the floating link. The latter two cases address a problem that is encountered in linkage design; namely, the need to specify limits that certain variables may range through as opposed to specifying fixed values that constrain the design unnecessarily, thus increasing the total number of designs from which to choose. As a result of this new approach, two planar regions, representing all permissible dyad ground-pivot locations and all permissible dyad moving-pivot locations, are identified and plotted. The program uses the properties of the circle-point circles (K1-circles) and the center-point circles (M-circles) throughout the synthesis procedure. MKCIRCLES also allows the designer to define a region in which the ground-pivots are constrained to lie and determine the corresponding moving-pivot region (and vice versa). The program is shown to be a useful design tool and provides greater geometric and kinematic insight into the general three-precision-position synthesis problem.

Instrumentation for detecting channelling radiation in the high-voltage electron microscope

1983 ◽  
Vol 41 ◽  
pp. 318-319
Author(s):  
J. H. Butler ◽  
C. J. Humphreys
Keyword(s):  
Monochromatic Light ◽  
Incident Beam ◽  
Laboratory Frame ◽  
Relativistic Electrons ◽  
Voltage Electron ◽  
Dipole Emission ◽  
Sinusoidal Oscillations ◽  
Pass Through ◽  
Incident Beam Energy ◽  
Increasing Function

Electromagnetic radiation is emitted when fast (relativistic) electrons pass through crystal targets which are oriented in a preferential (channelling) direction with respect to the incident beam. In the classical sense, the electrons perform sinusoidal oscillations as they propagate through the crystal (as illustrated in Fig. 1 for the case of planar channelling). When viewed in the electron rest frame, this motion, a result of successive Bragg reflections, gives rise to familiar dipole emission. In the laboratory frame, the radiation is seen to be of a higher energy (because of the Doppler shift) and is also compressed into a narrower cone of emission (due to the relativistic “searchlight” effect). The energy and yield of this monochromatic light is a continuously increasing function of the incident beam energy and, for beam energies of 1 MeV and higher, it occurs in the x-ray and γ-ray regions of the spectrum. Consequently, much interest has been expressed in regard to the use of this phenomenon as the basis for fabricating a coherent, tunable radiation source.

Sign in / Sign up

Export Citation Format

Share Document