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عدد المساهمات : 19001 التقييم : 35505 تاريخ التسجيل : 01/07/2009 الدولة : مصر العمل : مدير منتدى هندسة الإنتاج والتصميم الميكانيكى
| موضوع: كتاب Jig and Fixture Design الخميس 17 مارس 2022, 12:02 am | |
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أخواني في الله أحضرت لكم كتاب Jig and Fixture Design, Fifth Edition Edward G. Hoffman
و المحتوى كما يلي :
Contents Preface Xi Section I Basic Types and Functions of Jigs and Fixtures 1 Unit 1 Purpose of Tool Design 1 Objectives 1 Tool Design 1 Tool Design Objectives 1 Tool Design in Manufacturing 1 Planning the Design 2 Challenges to the Tool Designer 3 Requirements to Become a Tool Designer 6 Summary 6 Review 6 UNIT 2 TYPES AND FUNCTIONS OF JIGS AND FIXTURES 8 Objectives 8 Jigs and Fixtures 8 Classes of Jigs 8 Types of Jigs 9 Types of Fixtures 13 Classification of Fixtures 17 Summary 19 Review 19 UNIT 3 SUPPORTING AND LOCATING PRINCIPLES 21 Objectives 21 Referencing Basic Rules for Locating 21 Planes of Movement 25 Locating the Work 26 Summary 38 Review 38 UNIT 4 CLAMPING AND WORKHOLDING PRINCIPLES 41 Objectives 41 Workholders 41 Basic Rules of Clamping 41 Types of Clamps 43 Non-Mechanical Clamping 53 Special Clamping Operations 60 Clamping Accessories 61 Summary 62 Review 63 UNIT 5 BASIC CONSTRUCTION PRINCIPLES 65 Objectives 65 Tool Bodies 65 Preformed Materials 66 Drill Bushings 67 Set Blocks 72 Fastening Devices 73 Summary 86 Review 86 SECTION II CONSIDERATIONS OF DESIGN ECONOMICS 89 UNIT 6 DESIGN ECONOMICS 89 Objectives 89 Considerations of Design Economics 89 Design Economics 89 Design Economy 89 Economic Analysis 90 Comparative Analysis 95 Summary 97 Formula Summary 98 Review 99 UNIT 7 DEVELOPING THE INITIAL DESIGN 100 Objectives 100 Predesign Analysis 100 Designing Around the Human Element 102 Previous Machining Operations Developing Tooling Alternatives 107 Note Taking 107 Summary 107 Review 108 UNIT 8 TOOL DRAWINGS 109 Objectives 109 Tool Drawings versus Production Drawings 109 Simplified Drawings 110 Making the Initial Drawing 115 Dimensioning Tool Drawings 116 Millimeter and Inch Dimensioning 118 Geometric Dimensioning and Tolerancing 122 Supplementary Symbols 126 Geometrically Dimensioned and Toleranced Tool Drawings 132 Computers in Tool Design 132 Summary 134 Review 136 SECTION III DESIGNING AND CONSTRUCTING JIGS AND FIXTURES 139 UNIT 9 TEMPLATE JIGS 139 Objectives 139 Template Jigs 139 Variations of Template Jigs 139 Design Procedures 141 Tool Design Application 146 Summary 146 Review 149 UNIT 10 VISE-HELD AND PLATE FIXTURES 150 Objectives 150 Vise-Held Fixtures 150 Designing a Vise-Held Fixture 151 Plate Fixtures 155 Designing a Plate Fixture 156 Calculating Cam Clamps 158 Tool Design Application 165 Cam Design Application 168 Summary 168 Review 168 UNIT 11 PLATE JIGS 170 Objectives 170 Plate Jigs 170 Designing a Plate Jig Designing a Table Jig 177 Designing a Sandwich Jig or a Leaf Jig 181 Tool Design Application 184 Summary 185 Review 188 UNIT 12 ANGLE-PLATE JIGS AND FIXTURES 189 Objectives 189 Variations and Applications 189 Designing an Angle-Plate Jig 191 Designing an Angle-Plate Fixture 194 Tool Design Application 200 Summary 200 Review 203 UNIT 13 CHANNEL AND BOX JIGS 204 Objectives 204 Channel Jigs 204 Designing a Channel Jig 205 Box Jigs 208 Designing a Box Jig 208 Tool Design Application 212 Summary 213 Review 213 UNIT 14 VISE-JAW JIGS AND FIXTURES 216 Objectives 216 The Machine Vise 216 Locating Work in Vise-jaw Workholders 217 Designing a Vise-jaw Jig 219 Designing a Vise-jaw Fixture 222 Tool Design Application 224 Summary 226 Review 227 SECTION IV SPECIALIZED WORKHOLDING TOPICS 231 UNIT 15 POWER WORKHOLDING 231 Objectives 231 Types of Power-Workholding Systems 231 Basic Operation of Power-Workholding Systems 235 Benefits of Power Workholding 236 Summary 237 Review UNIT 16 MODULAR WORKHOLDING 239 Objectives 239 Modular Fixturing Systems 240 Modular Fixturing Applications 250 Summary 255 Review 256 UNIT 17 WELDING AND INSPECTION TOOLING 257 Objectives 257 Tooling for Welding Operations 257 Modular Fixturing for Welding 260 Inspection Fixtures 263 Summary 266 Review 268 UNIT 18 LOW-COST JIGS AND FIXTURES 269 Objectives 269 Chucks and Chucking Accessories 269 Collets and Collet Accessories 275 Vises and Vise Accessories 284 Specialty Clamps and Workholding Devices 294 Summary 302 Review 303 UNIT 19 TOOLING FOR NUMERICALLY CONTROLLED MACHINES 304 Objectives 304 Introduction 304 Basic N/C Operation 304 The Cartesian Coordinate System 305 Incremental and Absolute Programming 307 Types of N/C Systems 308 Tooling Requirements for Numerical Control 309 Types of Workholders 309 Summary 314 Review 315 UNIT 20 SETUP REDUCTION FOR WORKHOLDING 316 Objectives 316 Benefits of Setup Reduction 316 The Setup Reduction Process 317 Summary 325 Review 326 UNIT 21 TOOL MATERIALS 309 Objectives 327 Properties of Tool Materials Ferrous Tool Materials 330 Nonferrous Tool Materials 334 Nonmetallic Tool Materials 336 Designing with Relation to Heat Treatment 340 Summary 342 Review 342 APPENDIX 345 GLOSSARY 347 PROFESSIONAL ORGANIZATIONS 357 INDEX Accumulator. A device installed between the clamps and the power source in a power-workholding system. It is charged with either fluid or gas and maintains the necessary pressure in the system when the power is disconnected. Adjustable Locator. A locator used on jigs and fixtures and made to be adjusted after installation on the tool body. Adjustable Support. A support, or locator, positioned under the part and made to be adjusted to suit individual parts. Air-Assisted Hydraulic System. A form of powerworkholding system where compressed air is used to activate the hydraulic pressure through a booster. This is the most common form of powerworkholding system. Allowance. The intentional difference between the sizes of mating parts in an assembly. Alloy. A mixture of metals that have been combined to form the alloy in order to gain desired characteristics. Alloy Steel. A steel made up of several substances in addition to carbon and iron. American Sequence. A sequence of information in a feature control symbol. The sequence is geometric characteristic symbol, datum reference, and tolerance value. Angle-Plate Fixture. A modified form of plate fixture used to machine a part at an angle to its locator. Angle-Plate Jig. A modified form of plate jig used to machine a part at an angle to its locator. Angularity. The geometric characteristic that specifies a specific angular relationship between two surfaces of a part. Assembly Drawing. A mechanical drawing that shows all the parts and elements of a tool in their assembled form. Basic Dimension. A theoretically perfect dimension used to locate part features or datums. This type of dimension is shown enclosed in a box on the part drawing. Basic Size. The size of a part to which the tolerance values are applied to obtain the limits of size. Bilateral Tolerance. The tolerance value that may go in both a plus and a minus direction from the basic size. Bismuth Alloys. A group of metals having a bismuth base which is used primarily for cast tooling parts. These alloys are commonly referred to as low-melt alloys. Booster. A device that provides the power to operate a power-workholding system. Boosters are classified as either air operated or electrically operated. GlossaryBoring Jig. A type of jig specifically designed for boring operations. This jig normally has some type of tool guide, or bushing, on both sides of the hole being machined rather than on just one side, as is the case with a drill jig. Box Jig. A form of jig that completely encloses the part being machined. This jig is also called a tumble jig. Bracket Method. A dual dimensioning method in which the converted dimensions are shown in brackets ([ ]). Break-Even Point. The minimum number of parts required for a tool to pay for itself. Any number of parts less than this break-even point will result in a loss, while any number over this point will result in a profit. Brinell Hardness. A specific measure and rating of a material’s resistance to penetration or indentation. A Brinell hardness test is performed by forcing a steel ball 10 millimeters in diameter into the material with a force, or load, of 3000 kilograms. Brittleness. The characteristic of a metal that causes it to fail when sudden loads are applied. This is normally considered to be a negative quality, but in some cases, as with shear pins, it may be a positive characteristic of the material. Built-Up Tool Body. A form of tool body used for jigs and fixtures in which the entire construction consists of a series of parts screwed and doweled together. This is the most common and least expensive tool body. Burr. The rough ribbon, or ridge, of metal formed on both sides of a machined hole. The larger ridge, normally on the exit side of the hole, is referred to as the primary burr, while the smaller ridge, on the side of the hole where the drill enters, is called the secondary burr. CAD. The acronym for computer aided design. CAM. The acronym for computer aided manufacturing. Cam. A mechanical device used to clamp parts in a jig or fixture. The two fundamental types are flat and conical. Cap Screw. A type of mechanical fastener used to assemble the parts of a jig or fixture. Typically these fasteners have a cylindrical head with an internal hexagon drive. Carbon Steel. A specific type of steel composed mainly of iron and carbon. The three standard types or designations of carbon steel are low, medium, and high carbon. Cast Iron. A cast ferrous material with a higher carbon content than carbon steel; it is used for both manufactured parts and tooling. Composed mainly of iron, carbon, and other elements. Cast Tool Bodies. Tool bodies made from cast iron, cast aluminum, or other castable materials. Channel Jig. A specific style of jig that has a Ushaped channel as its major structural element. Chuck. A commercially available workholder, used mainly on a lathe or grinder, which holds parts with a series of jaws. Circular Runout. The geometric characteristic that specifies a relationship between two or more concentric diameters of a part measured in single line elements around the part. Circularity. The geometric characteristic that specifies a condition of roundness in a part feature. Clamp. A mechanical device used to hold a part securely in a jig or fixture. Clamping Forces. The forces exerted by the clamping device while holding the part in the workholder. Closed Jig. A jig that encompasses a part on more than two sides. CNC. Computer numerical control. The abbreviation is used to describe a system where a computer controls the movements of a machine tool through a direct interface, floppy disk, or a magnetic tape used as an input medium. Collet. A mechanical device used to hold parts, normally of a specific diameter or size, that are to be turned or rotated around a central axis. Component Libraries. The groups of individual types of components, such as clamps, locators, etc., used for fixturing applications with CAD. Concentricity. The geometric characteristic that specifies a concentric relationship between two or more diameters of a part. Conical Wedge. A wedge that has a tapered form, similar to a solid mandrel. 348 GlossaryContinuous Path. A programming method used for numerically controlled machine tools in which the position of the tool is constantly controlled throughout the complete machining cycle. Conversion Chart Method. A dual dimensioning method in which the converted dimensions are shown in a chart along with the design units they reference. Critical Dimension. A part dimension that controls the size or location of a part feature that is very important to the overall function of the part. Cutting Forces. The forces exerted against the part by the cutter during the machining cycle. Cylindrical Cam. A cam design that uses a cylindrically shaped element to activate the clamping device. This cam may use the outside surface of the cylinder or a groove cut into the surface of the cylinder. Datum. A point, line, surface, or feature considered to be theoretically exact that is used to locate the part or the geometric characteristic features of the part. Datum Feature Symbol. The datum reference letter contained in a rectangular box and used to note the datum surfaces on the part. Datum Reference. The letter values contained in the feature control symbol which reference the control to the appropriate datum feature symbols. Degrees of Freedom. The 12 degrees, or directions, of movement an unrestricted part is free to make. These directions include six radial and six axial directions of movement. Detailed Drawing. A mechanical drawing that shows each part of a larger assembly drawn in a series of individual views. This is the primary type of drawing used to manufacture each part. Diamond Pin. A specific type of relieved locating pin used for jigs and fixtures. The pin, when viewed from the end, has a diamond shape. Dowel Pin. A hardened steel pin used to locate assembled parts of a workholder or as a locating device to accurately position the parts in a jig or fixture. Dowel-Pin System. A modular tooling system that uses a series of precisely located holes and dowel pins to accurately position and locate the various elements used to build the modular tool. Drill Bushing. A hardened steel or carbide bushing used to guide and support a cutting tool, such as a drill, throughout its machining cycle. Drill Jig. A special purpose tool used to accurately position, support, and hold a workpiece so that a variety of operations may be performed. Drill jigs also use some type of cutter guiding device, such as a drill bushing, to accurately position and support the cutting tool. Dual Dimensioning. A dimensioning system used to show both inch and millimeter dimensions on the same print. Duplex Tools. Jigs and fixtures designed and constructed so that two parts may be machined. As one part is machined, the other station is loaded or unloaded. When the first part is complete, the second part is moved to the cutter and the first is unloaded and a new part loaded. This process is continued until all the parts are completed. Eccentricity. The condition of a part in which two diameters do not share the same center-line positions. Ejector. A device, contained within a workholder, that is used to aid in the removal of the part from the tool. Epoxy Resins. A family of plastic tooling compounds used to prepare cast nests or other types of workholding or locating devices. They normally consist of two elements, a resin and a hardener, that are mixed and cast to prepare the required element. Equalizing Support. A supporting device used to spread the support over a larger area of the part. It normally has two contact points; as one is depressed, the other rises. Expanding Mandrel. A mechanical holding device that grips the workpiece in an internal diameter or other shaped hole and exerts outward pressure to hold the part. Feature Control Symbol. The symbol used in geometric dimensioning and tolerancing which contains the geometric characteristic symbol, tolerance value, and datum reference. Feeler Gauge. A flat metal strip of precise thickness that is used to reference the cutters to a fixture by establishing their relationship to the set block. Glossary 349Ferrous Metals. Metals and alloys that have a base primarily of iron. F.I.M. The abbreviation for full indicator movement. Fixed-Limit Gauge. A gauge that has fixed limits of size. Many times these gauges are go–no-go and check the upper and lower limits of the part size. Fixed-Renewable Bushings. Easily replaceable drill bushings designed to be used in a liner bushing and which are held in place with a lock screw or clamp. Fixed-Stop Locators. External locators that are not adjustable. All types of nonadjustable external locators are fixed-stop locators. Fixture. A workholding device that holds, supports, and locates the workpiece while providing a referencing surface or device for the cutting tool. Fixture Key. A square or rectangular block attached to the base of a jig or fixture which locates and aligns the workholder in the “T”-slots of the machine tool on which it is used. Flat Cam. A cam design that uses the outside profile of a flat plate to generate the desired movement. The two principal types of flat cam are the spiral and the eccentric. Flatness. The geometric characteristic that specifies an amount of permitted variation from a perfectly flat surface. Flush-Pin Gauge. A type of inspection fixture that uses a pin to indicate the part’s compliance to specific sizes. Foolproofing. The process of installing a device on a jig or fixture to prevent improper loading of parts in the tool. Form Characteristics. The geometric characteristics that control the form of a part. These include straightness, flatness, circularity, and cylindricity. Gang Milling. A milling operation using more than two milling cutters to obtain a specific part size, shape, or form. Gauge. A mechanical device of a known and precise size, used to check or compare part sizes. Gauging Fixture. A fixture that uses some type of gauge to check the sizes of a part. Geometric Characteristic Symbols. The symbols used to show the specific type of feature control required for the part. Geometric Dimensioning and Tolerancing. An exact dimensioning method used to show the exact specifications of part size and form. Go–No-Go Gauges. Gauging devices used to check the upper and lower limits of a part size. Groove Pin. A pin made with a series of grooves or ridges around its profile. Its use is similar to that of a dowel pin, but it is not as accurate because it is positioned in a drilled rather than a reamed hole. Hardness. The property of a material that permits it to resist penetration or indentation. Heat Treatment. The process of using heat to modify the properties of a metal. Hook Clamp. A type of commercially available clamp used for holding parts in jigs and fixtures. Inch. The base unit used for linear measurements in the U.S. Customary System of measurement. Indexing. The process of accurately spacing holes or other details around a central axis. Inspection. The process of checking a workpiece to verify its conformity to the specifications in the part print. Inspection Tooling. Fixtures and other tools used to aid in the process of inspecting parts. International Sequence. The sequence of information in a feature control symbol. The sequence is geometric characteristic symbol, tolerance value, and datum reference. Jaws. The mechanical devices or elements of a workholder, such as a vise or chuck, that actually contact the part being held. Jig. A workholding device that holds, supports, and locates the workpiece while providing a guiding device for the cutting tool. Jig Pin. A pin used to hold approximate alignment between two or more parts of a tool. It can act as a hinge pin or locator pin and can also be used to attach removable parts to a jig or fixture. Jig Plate. The part of a jig that contains the drill bushings. Knurled Bushings. Drill bushings made with a knurled outside diameter to provide a positive gripping surface in soft materials or to hold the bushings when they are cast into the jig plate. Lead Time. The time between the design and the construction of a jig or fixture. 350 GlossaryLeaf Jig. A specific jig design that uses a hinged leaf as a jig plate. Least Material Condition. The condition of a part feature in which it has its least amount of material allowed by the tolerance. It is the largest size of an internal feature and the smallest size of an external feature. It is also referred to as the LMC. Limit Dimensions. Dimensions shown on a part drawing that specify the maximum and minimum sizes of a part feature. Limits of Size. The maximum and minimum sizes of a part as specified by the tolerances and the basic size. Liner Bushing. A drill bushing specifically used to provide a hardened, wear-resistant hole in a jig plate in which either slip- or fixed-renewable drill bushings are installed. Location Characteristics. The geometric characteristics that control the location of part features. These characteristics include position and concentricity. Locator. A device used to establish and maintain the position of a part in a jig or fixture to insure the repeatability of the workholder. Low-Melt Alloys. A group of metals having a bismuth base that are used primarily for cast tooling parts. Machinability. The measure of a material’s ability to be machined. Some materials are soft and have good machinability characteristics, while others are harder and have poor machinability. Machine Vise. A vise designed and intended to be used on a machine rather than on a bench. The most common types of machine vise are the milling machine vise and the drill press vise. Magnetic Chuck. A mechanical workholder that uses magnetic force to hold a ferrous workpiece. These chucks may use either an electromagnetic or a permanent-type magnet. Mandrel. A solid bar used to mount and drive parts from a central hole. This bar appears to be cylindrical, but is actually conical since it has a .006- inch taper per foot. Manifold. A unit used to split or redirect the hydraulic fluid in a power-workholding system. The manifold has one inlet and many outlets for several power clamps. Maximum Material Condition. The condition of a part feature in which it has the maximum amount of material permitted by the tolerance. It is the smallest size of a hole or the largest size of an external part feature. This is also referred to as the MMC. Metric System. The common term used to identify the Systeme Internationale d’Unites, or the International System of Units. Millimeter. The base unit of linear measurement in the Systeme Internationale d’Unites for manufacturing purposes. Modifiers. The letter values used to modify tolerance values or datum references in a feature control symbol. These include the circled letters M, L, and S. Modular Tooling. A system of individual parts assembled for a variety of jigs and fixtures. Another term frequently used to describe these tools is erector set tooling. Multistation Tooling. Workholders that are capable of holding and positioning more than one part at a time. N/C. Numerical control. N/C systems typically use either punched paper or mylar tape to convey the instructions to the machine tool. Nest Locator. A type of locating device that encloses all or part of the outer profile of a part. Numerical Control. An automated manufacturing system that uses numerical data, usually on a punched tape or in a computer, to operate a variety of machine tools. Nuts. Mechanical fastening devices used to secure bolts in assembled units. Oil-Groove Bushing. A special-purpose drill bushing that has grooves cut into the inner surface to provide complete lubrication to the cutting tool or boring bar used in the drill bushing. Open Jig. A variation of a drill jig, used to machine parts on less than two sides. Orientation Characteristics. The geometric characteristics that control the orientation of part features. These include angularity, parallelism, and perpendicularity. Parallelism. The geometric characteristic that specifies a relationship between two parallel surfaces of a part. Glossary 351Part. The object, or workpiece, machined in a jig or fixture. Part Drawing. The drawing, or print, of the object to be made or machined. Perpendicularity. The geometric characteristic that specifies a perpendicular relationship between two surfaces of a part. Pin. A cylindrical fastener that is normally pressed into a premachined hole for the purpose of aligning or holding parts of an assembled workholder. Planes of Movement. The three principal planes, or axes, or a part used to reference the twelve degrees of freedom. These are generally identified as X, Y, and Z. Plate Fixture. A fixture that has a plate as its main structural component. Plate Jig. A jig with a plate as its main structural component. Pneumatic Workholding System. A form of power-workholding system that uses air pressure to operate all workholding devices. Point-to-Point. A programming method used for numerically controlled machine tools, in which the position of the tool is controlled between a series of specific locations, or points. Only the position of these points is important; the path the tool takes between these points is not important. Position. The geometric characteristic that specifies a relationship between a part feature and a central axis, or center Position Method. A dual dimensioning method in which the converted dimensions are shown either below or to the right of the design units. The units are separated with a slash (/) for horizontal dimensions and a straight line (–) for vertically placed dimensions. Power Clamping. A clamping system, either hydraulic, pneumatic, or a combination of both, used to activate and hold the clamping pressure. Precast Tool Bodies. Commercially available tool bodies made from cast aluminum, cast iron, or cast steel; they need only minimal machining to accommodate the various clamps and locators required for the part being held. Precision Ground Materials. Commercially available tooling components used in the construction of built-up tool bodies. The two principal types are cylindrical, called drill rod, and flat. Preformed Materials. Commercially available materials made in a variety of precast forms which are used to construct built-up tool bodies. Press-Fit Bushings. Drill bushings specifically designed and intended to be pressed into a hole in the jig plate. The friction and pressure of the press fit are the forces that hold the bushing in place. Primary Locators. The locators used to locate, or reference, the primary locating surface of the part. Process Planning. The act, or process, of planning the step-by-step procedure to be used to manufacture or machine a workpiece. Production Plan. The document specifying the exact means and methods to be used to manufacture a part or product. Production Run. The specific group, or number, of parts to be made at one time. Profile. The external edges, or surfaces, of a part. Profile Characteristics. The geometric characteristics that control the form, or shape, of a part profile. These include the profile of a line and the profile of a surface. Profiling Fixture. A fixture specifically designed to aid in machining the external edges of a part. Projected Tolerance Zone. The imaginary zone projected above a part feature, such as a hole, to insure assembly with a mechanical fastener passing through both the tolerance feature and the projected thickness of the mating part. Projection. A means of establishing the relative position of the views in a mechanical drawing. The two main types of projection in use today are first angle (Europe) and third angle (United States and Canada). Pump Jig. A commercially available tooling device used as the major structural element in some types of jigs. This device consists of a base and a top plate connected and aligned with two or more posts. The top plate is moved up and down with an integral handle. Quarter-Turn Screw. A commercially available fastening device used for clamping on some types of workholders. The head of this screw is flat and is usually used to clamp tooling ele- 352 Glossaryments, such as leaves, where the screw is positioned in a slot and turned 90 degrees (one quarter turn) to grip the top plate. Reference Dimension. A dimension shown on a part print for information purposes and used for reference rather than manufacture. Such a dimension is shown in parentheses or with the abbreviation “REF.” Reference Surface. A part surface used to reference the part. It may also be referred to as a datum surface. Referencing. The proper positioning of the workpiece with reference to the tool. Regardless of Feature Size. A modifier used to indicate that the tolerance value shown applies regardless of the size of the feature or datum. Releasing Agent. A compound used in conjunction with epoxy resins to prevent the resins from adhering to the part used as a pattern. Renewable Bushings. Easily replaceable drill bushings designed to be used in liner bushings and held in place with a screw or clamp. The two principal variations are the fixed-renewable and the slip-renewable bushing. Repeatability. The feature of a workholder that permits the parts being machined to be duplicated within the stated limits of size, part after part. Resins. The compounds, usually epoxy, mixed together to make resin tools. Retaining Rings. Spring steel rings that are used in place of nuts or screws to hold the part on which they are installed in some relative position. Rise. The term used to describe the movement of a cam per degree of arc. Rockwell Hardness. A specific measure and rating of a material’s resistance to penetration or indentation. A Rockwell hardness test is performed by forcing either a diamond cone or a steel ball into the surface of a part under a known and controlled load. Rotary Tooling. A term used to describe indexing jigs and fixtures. Runout Characteristics. The geometric characteristics that control the runout of a part. These include circular runout and total runout. Sandwich Jig. A type of drill jig that holds the workpiece on two opposite sides. It may be used to support the part or to machine the part from two sides. Screw Clamp. A clamping device that uses a screw thread to clamp the part. Secondary Locator. A locator used to reference the secondary locating surface of the part. Serrated Bushing. A drill bushing made with a serrated outside diameter to provide a positive gripping surface in soft materials or to hold the bushing when it is cast into the jig plate. Set Block. A gauging device included on many fixtures to aid in setting the cutters to suit the workpiece. Set Screw. A mechanical fastening device that is generally made without a head and used for adjustable locators or as a locking device for other applications. Setup Gauge. A special-purpose gauge used in conjunction with a set block to establish the proper cutter position. A feeler gauge is a form of setup gauge. Shear Strength. The measure of a material’s resistance to forces acting in opposite directions, causing a shearing effect on the part. Shop-Air System. The compressed air system found in machine shops. The shop-air system provides power to a variety of shop equipment. Air tools, coolant systems, and power-workholding systems rely on this power source. The most common shop-air systems use compressed air at a pressure of 90 to 100 pounds per square inch. Sight Locators. Locators used on jigs and fixtures that are intended to be used for approximate location. The part may be aligned against milled slots or scribed lines. Slip-Renewable Bushings. Easily replaceable drill bushings designed to be used in a liner bushing and held in place with a screw. Slot Nuts. A term used to describe T-nuts. Socket-Head Cap Screws. A type of mechanical fastener used to assemble the parts of a jig or fixture. Typically these fasteners have a cylindrical head with an internal hexagon drive. Software. The medium used to convey specific instructions to a computer. Solid Locators. Locators used on jigs and fixtures which are solid and nonadjustable. Spiral Cams. A type of flat cam that has a shape similar to an involute curve. Glossary 353Split Pin. A pin made from flat material formed into a cylindrical shape with a split on one side. Its use is similar to that of a dowel pin but it isn’t as accurate because it is used in a drilled rather than a reamed hole. Also called roll pin. Straddle Milling. A milling operation using two milling cutters to mill two sides of a part at the same time. Straightness. The geometric characteristic that specifies a relationship between a part feature and a true straight plane or line. Strap Clamp. A specific type of clamping device that uses a metal bar, similar to a strap, to hold the part securely to the workholder. The basic elements of this clamp are the strap, the hold-down bolt, and the heel pin or block. Structural Sections. Commercially available materials made in a variety of preformed shapes which are used to construct built-up tool bodies. Subplate. A plate containing many drilled and tapped holes to which a variety of different components and clamps may be attached to form a crude type of modular tooling. Support. A locator placed under a workpiece. Swing Clamp. A variation of a screw clamp consisting of an arm that swings about a stud at one end and contains the screw clamp at the other end. Systeme Internationale d’Unites. The system of measurement frequently called the metric system. T-Bolt. A mechanical fastener that has a head designed to fit into the “T”-slots of machine tools. Usually used to mount workholders to a machine tool. T-Nut. A nut made specifically for use in the “T”- slots of machine tools. Using these nuts permits standard bolts to be used to attach the workholder or other elements. “T”-Slot System. A modular tooling system that uses a series of precisely located “T”-slots to accurately position and locate the various elements used to build the modular tool. Table Jig. A variation of the basic plate jig that uses legs to elevate the jig off the machine table. Tacking. A preliminary welding process in which the joined edges are tacked, or welded, with small widely spaced weld deposits to hold the relative position prior to finish welding. Template. A plate that duplicates the desired part configuration and is used as a guide for layout work or for light machining. Template Jig. A jig that has a template as its major structural element. Tensile Strength. The measure of a material’s resistance to being pulled apart. The tensile strength rating is the principal means used to classify the strengths of various metals. Tertiary Locator. A locator used to reference the tertiary locating surface of the part. Thread Inserts. Steel inserts used to provide a more wear-resistant threaded hole in soft tooling elements, such as aluminum tool bases. Throw. The radial movement of a cam about its mounting point or hole. TIR. The acronym for total indicator reading. Toggle Clamp. A commercially available style of clamping device that uses a series of levers to operate and hold the position of the clamp. Tolerance. The amount of variation, or deviation, permitted in the size of a part. Tombstone. A commercially available tooling block that is mounted on machining centers and similar machine tools to provide multiple mounting surfaces for workholders. Tool Body. The major structural element of a jig or fixture. Tool Design. The science, or process, of designing jigs, fixtures, or any other special-purpose tools required for manufacturing purposes. Tool Drawings. The mechanical drawings made and used to build special-purpose tools. Tool Force. The force exerted against a workpiece by the cutting tool. Tool Steel. A type of alloy steel made to very close specifications and primarily used for tools or similar types of parts. Tooling Estimate. A management guide to the overall cost and benefit of a special-purpose tool. This estimate shows the cost of the tool and the relative cost of the operation with the tool and with alternate methods of manufacture. Toolmaker. A skilled craftsman who specializes in making the special-purpose tools required for manufacturing. 354 GlossaryTotal Runout. The geometric characteristic that specifies a relationship between two or more concentric diameters of a part measured totally around and across the part feature. Toughness. The property of a material that allows it to resist fracture from sudden loads. Trunnion Jig. A type of jig used to accommodate large parts that must be machined on several sides. Tumble Jig. A form of jig that completely encloses the part being machined. It is also called a box jig. Unilateral Tolerances. Tolerance values that may go only in a single direction, either plus or minus, from the basic size. U.S. Customary System. The inch-based system of linear measurement. Urethane. A nonmetallic tooling material used for applications in which the tool must be nonmarring. Vacuum Chuck. A mechanical workholder that uses the force of a vacuum to hold a nonporous workpiece. This chuck may be used on any ferrous, nonferrous, or nonmetallic material that will hold a vacuum. Vee Locators. Locating devices that have a V form. They are very useful for cylindrically shaped parts. Vise-Jaw Tooling. Special-purpose jigs and fixtures made from blanks that are the same dimensions as those of the replaceable jaws of a machine vise. Washers. Mechanical fastening devices used under nuts, screws, and bolts either to prevent damage when the fastener is tightened or to provide a mechanical lock to prevent loosening. Wear Block. Any device used to prevent premature wear to any surface of a workholder. Wear Resistance. The ability of a material to resist wear or abrasion. Wedge Clamp. A type of clamping device that uses a wedge to activate and hold the clamped part. Wedge. A mechanical clamping device that uses the principle of the inclined plane. The two primary variations of the wedge are flat and conical. Workholder. A term used to describe jigs and fixtures. Glossary 355Aluminum Association 750 Third Avenue New York, NY 10017 American Iron and Steel Institute 1000 16th Street NW Washington, DC 20036 American National Standards Institute 1430 Broadway New York, NY 10018 American Society of Mechanical Engineers United Engineering Center 345 East 47th Street New York, NY 10017 American Society for Metals 9513 Kinsman Road Metals Park, OH 44073 National Machine Tool Builders Association 7901 Westpark Drive McLean, VA 22101 National Tool, Die & Precision Machining Association 9300 Livingston Road Washington, DC 20022 Society of Manufacturing Engineers One SME Drive P.O. Box 930 Dearborn, MI 48128 Professional OrganizationsNote: Boldface numbers indicate illustrations and tables. 5C collets, 275, 276 absolute programming, numerically controlled (NC) machines and, 307–308, 307 accessories, clamping and workholding, 61–62, 64 accumulators, power (hydraulic/pneumatic) clamps and, 234 accuracy requirements, 101, 102 adapter ring, part drawing and production plan, 166 adjustable ball lock jig pins, 82–83, 83 adjustable stop locators, 35, 35, 36 adjustable supports, 28, 28, 29 adjusting blocks, 25, 25 air assisted power (hydraulic/pneumatic) clamps, 232–234, 233 AISI tool steel identification, 332–334, 333, 334 alignment pins, 80, 80 allowance, 90, 121, 122 alloy steels, 331–332 alloys, 330–332, 335–336 aluminum, 65, 334, 334, 335 American Society for Testing Materials (ASTM), 335–336 angle plate fixture, 13–14, 17, 194–203 clamping part in, 199, 199 locating part in, 196–199, 199 tool body design in, 199–200, 200 angle plate jig, 11–12, 12, 189–194 bushing location in, 193–194, 195 designing, 191–194 indexing part in, 193 locating, supporting, clamping part in, 193, 194 supporting, 189, 190 tool body construction, 189, 190 tool body design, 194 angle plate tool body, 116 ANSI Y14.5M-1994 dimensioning standard, xiii assembly drawings, 109, 110, 111 automatic bar feeder, 286 automatic sequencing, power (hydraulic/pneumatic) clamps and, 237 Automatic Toggle Clamp, 299, 299, 300 auxiliary clamp, 208 auxiliary support, 191 axes, numerically controlled (NC) machines and, 304, 305 Indexball element clamps, 248–250, 250, 251 ball lock jig pins, 82–83, 83 Ball Lock mounting system, 299, 300, 301, 302 ball plunger, 194, 195 basic dimension, 131, 132 Bi Lok Machine Vise, 285, 289 bismuth alloys, 336 block locators, 218, 218 bolts, 75–76, 76 boring jigs, 8, 9 box jig, 9, 12, 13, 208–212, 210 break-even point calculation, 94–95 brittleness, 330 built-up tool bodies, 65–66 burr clearance, construction principles and, 72 bushing location, 29, 30, 221–222, 339 angle plate jig, 193–194, 195 box jig, 210–212, 213 channel jig, 207–208, 208 leaf or sandwich jig, 184, 185 plate jig and, 173–176, 176 table jig, 180 template jigs and, locating in, 142–145, 144, 145 butt plate, 143, 147, 152, 157 cables, to attach workbody to pins, 81, 82 cam action clamps, 48–49, 48, 49, 154, 158–165 cam edge clamps, 248, 249 cap screws, 73–74, 74 carbide bushings, 71 carbon steel, 330–331 Cartesian coordinate system, numerically controlled (NC) machines and, 305–307, 307 case hardening, 330 cast chuck plates, 59, 60 cast iron, 65, 330 cast parts, 320, 320 cast section, 154, 155 cast tool bodies, 65 cast-bracket materials, 66, 66 castings, 271 challenges of tool designer, 3–6 channel jig, 12, 13, 204–208, 204 chuck jaws, 269–271, 270 chucks, 53, 53 chucks and chucking accessories, 269–275 circular plate template jigs, 140–141, 141 Clamp Chuck System, 271, 273–274, 275 clamp positioning, 41 clamping and workholding, 41–64 accessories for, 61–62, 64 angle plate fixture and, 199, 199 angle plate jig, 193 basic rules of, 41–43 box jig, 210, 212 channel jig, 205, 207 chucks and vises in, 53, 53, 54 clamp positioning in, 41 clamping forces in, 42–43, 43, 44, 45 leaf or sandwich jig, 183–184, 184 manual devices for, 45, 46 modular workholding and, 244, 246–247, 246 multiple clamping devices for, 61, 63 nonmechanical clamping in, 53–60 nuts and washers in, 45, 46 odd shape clamping in, 61 plate fixtures, 158, 160 plate jig and, 173, 175, 176 power (hydraulic/pneumatic) clamps in, 45, 46, 51, 52, 231–238, 232 remote, using power, 236–237 special clamping operations in, 60–61 table jig, 177–180, 180 tool forces in, 42 types of clamps used in, 43–53 vise-held fixtures, 154, 154 clamping forces, 42–43, 43, 44, 45 clamps, 41, 294–302 classes of jigs, 8–9 classification of fixtures, 17–19 Claw Clamp, 299, 300 clearance, bushings, 71–72, 72 closed jigs, 9 closers, 275 collet blocks, 276–277, 277 collet stops, 277–279, 277, 278 360 Indexcollets and collet accessories, 275–284 comparative analysis, 95–97, 95, 97 component libraries, CAD, 132, 134, 136 Computer Aided Design (CAD), xii, xiii, 107, 110, 112–116, 132–134, 134–135 Computer Aided Manufacturing (CAM), xi, xiii computer numerical control (CNC), xi, 2, 304–315 conical wedge clamps, 49, 50 connector, 215 connector rod, 229 construction principles, 65–88 drill bushings in, 67–72, 68 fastening devices in, 73–86 preformed materials in, 66–67 set blocks in, 72–73, 74 tool bodies, 65–66 continuous path, numerically controlled (NC) machines and, 308, 309 contour of spiral cam, 164, 165 controlled length collets, 279–281, 280 controlled length work stops, 280–281, 280 conversion table, SI to U.S., 345 corners, in heat treatment, 341, 341 cost analysis, 90–95 cost per part calculation, 93–94 cost work sheet, 93 counterbalance, 200 coupler, 192, 197 critical dimensions, 117–118, 118 cutters plate fixtures, 158, 161 requirements for, type and size, 102 vise-held fixtures, 154–155 vise-jaw fixture, 226, 227 cylindrical cams, 49, 49 cylindrical locator, 207 datum reference, 122–126, 128, 129 dead length stop, 282–283, 285 dedicated workholders, 325 Demmeler modular fixturing system, welding operations and, 260–263, 261, 262 design phase, 4 detailed drawings, 109–110, 111 detent pins, 82, 83 diameter symbol, 130, 131 diamond pin locator, 25, 27, 31, 31 dimensional difference, 207 dimensioning basic dimension, 131, 132 dimensional differences and, 142, 144 geometric, 122–126, 265 geometrically dimensioned and toleranced, 132, 133 reference dimension, 131, 132 dimensioning tool drawings, 116–118, 117 millimeter and inch dimensioning in, 118–122, 119, 120 double-ended jig plate, 221, 221 dowel pin locators, 35, 35, 76–77, 78, 79 dowel pin systems, modular workholding and, 243–244, 245, 246 drafting sheets, standard, 121 drawings (See tool drawings) drill bushings, 67–72, 68 burr clearance in, 72, 73 clearance, 71–72, 72 installation of, 71, 71 jig plates and, 71 drill jigs, 8–9, 10 drilling attachment, vise mounted, 288 drilling fixture attachments, vise, 284 dual-dimensioned drawings, 118–122, 119 Dunham vacuum chuck, 58, 58 duplex fixture, 15, 18 duplicate locators, 24–25, 24 eccentric cam clamps, 48–49, 49, 161–163, 163 eccentricity, in cams, 161, 163 economics of design (See also low-cost jigs and fixtures; setup reduction for workholding), 89–99 analysis of costs in, 90–95 break-even point calculation in, 94–95 comparative analysis in, 95–97, 95, 97 Index 361cost per part calculation in, 93–94 labor expenses in, 91–93 low-cost jigs and fixtures in, 269–303 preformed materials and, 89 productivity versus tool cost, 90–91 secondary operations in, 90 simplicity in, 89 simplified drawings in, 90 standard components in, 89–90 tolerance and allowance in, 90 total savings calculation in, 94 edge clamping, 294 ejectors, 36, 36, 37 ElectraLock clamps, 59, 60 electromagnetic chucks, 54, 55, 56, 57 emergency collets, 275 enlargement ratios, 121, 121 epoxy resin, 65, 337–338 clamping and workholding, 61, 61 equalizing supports, 28, 30 ergonomics, 102–103 estimate, economics of design and, 91 expanding collets, 275, 283, 287 expanding jig pins, 83, 84 extended range bushings, 71, 71 external profile, locating, 33–36 eyebolts, 84, 85 failure of tools, heat treatment and, 341–342 fastening devices, 73–86 feature control symbols, 122, 122, 130 ferrous tool materials, 330–334 fixed heel blocks, 310 fixed limit gauges, 266, 267 fixed renewable bushings, 68–69, 69 fixed stop locators, 34, 35 fixtures, 8–20 flange rings, 41, 42 flat cams, 49 flat clamps, 294, 294 flat eccentric cam clamps, 48–49, 49 flat plate template jigs, 140, 141 flat spiral cams, 49, 49 flat surfaces, locating, 26–28 flat wedge clamps, 49 flexible manufacturing systems (FMS), xi flush pin gauges, 265–266, 266, 267 foolproofing, 23–24, 212 collet stops for, 278–279 forged parts, 271, 320, 320 formulas, economic, 98 full indicator movement (FIM), 265 full nest, 33–34, 33 gauging fixtures, gauges, 263–266, 263, 264 geometric characteristics symbols, 122–123, 123, 124–128 geometric dimensioning and tolerancing in, 122–126, 132, 133, 265 go/no-go gauges, 266, 267 Golden Rule of workholding, 324 grain in wood, 337 grid paper, 107 Grip Strip Tooling System, 298, 298, 299 groove pin locators, 35, 35 guide block, 211, 214 guides, drawing, 112–114, 114 handholds, 84, 85 hanger bracket, 198, 201 hardness scale, 327, 328 heat dissipation, welding operations and, 260, 260 heat treatment, 330, 340–341 high-carbon steel, 331 high-rise clamps, 246–247, 246 hinge clamp, 45, 45 hoist rings, 84–85, 86 Hold-All clamp, 297–298, 298 hook clamps, 47, 47, 48 housing cover, 159, 162, 174, 178 human element in design, 102–106 Hydra Jaw, 293–294, 293 hydraulic clamps (See power [hydraulic/pneumatic] clamps) 362 Index economics of design (cont.)incremental programming, numerically controlled (NC) machines and, 307–308, 307 independent clamping elements, 294–299 indexing fixture, 15, 18 indexing jig, 12–13, 14, 191 indexing parts, 193 initial design, 100–108 plate jig and, 176–177, 177 table jig, 180–181, 181 template jigs and, 145–146, 146 initial drawings, 115–116 Inserta Jaw chuck jaws, 271 inspection fixtures, 263–266 gauging, 263, 263, 264 measuring, 263–265, 264 supplement gauges and, 265–266 inspection phase, 5 installed locators, 34–35, 35 interchangeable fixture keys, 76, 76, 77 internal diameter, locating, 28–33, 30 jig pins, 77–83 jig plates, drill bushings and, 71 jigs, 8–20 just in time (JIT), xi Knollwood Vise Adapter, 292, 293 knurled bushings, 69–70, 70 L pins, 80–82 labor expenses, 91–93 laminated materials, 338–340, 339 latch clamp, 45, 45 lathe fixture, 271, 272 lathe-radius fixture, 17 layered object manufacture (LOM), 2 layout template, 139–140, 140 lead time, 65 leaf jig, 12, 14, 171, 172, 181–184 least material condition (LMC), 127–129, 129 lever strap clamps, 43–47, 44, 45 lifting devices, 83–86 limit dimensions, 117, 117 linear bushings, 69, 69 link lever, 202 link lever, part drawing and production plan, 187, 187 locating the work, 21–38, 115 angle plate fixture and, 196–199, 199 angle plate jig, 193 box jig, 210, 212 channel jig, 205, 207 ejectors, 36, 36, 37 external profile, 33–36 flat surfaces, 26–28 internal diameter, 28–33, 30 leaf or sandwich jig, 183–184, 184 modular workholding and, 244, 246 plate fixtures, 156–158 plate jig and, 173, 175 predesign analysis in, 101–102 relieved locators in, 31, 31 setup reduction for workholding and, 317 spring stop buttons and spring-locating pins, 36–38, 37 table jig, 177, 180 template jigs and, 142, 144, 145 vise-held fixtures, 151–154, 153 vise-jaw fixture, 224, 226 vise-jaw jig, 217–219, 218, 220–221, 221 welding operations and, 258 locators positioning, 21–25, 22, 24, 82 lock, 148, 166 LOM (See layered object manufacture) low-carbon steel, 330 low-cost jigs and fixtures, 269–303 chucks and chucking accessories, 269–275 collets and collet accessories, 275–284 specialty clamps and workholding devices, 294–302 vises and vise accessories, 284–294 low-melt alloys, clamping and workholding, 61, 62 machinability scale, 327, 329 machine handhold, 84, 85 Index 363machine reference sheet, 104–105 machine tool requirements, type and size, 102 machine vise, 216–217, 216, 217 machined nest locators, 218, 218 machining operations, type required, 101 machining operations, previous, 107 magnesium, 65, 335–336, 336 magnetic chucks, 54, 55, 56, 57 mandrels, 49, 50 manual devices for clamping and workholding, 45, 46 mass, unequal, in heat treatment, 340–341, 340 Master Jaw System, 281–283, 281 master plate system, modular workholding and, 241–242, 243 material selection, 100–101, 321–322, 327–343 ferrous tool materials in, 330–334 heat treatments and, 340–341 nonferrous tool materials in, 334–336 nonmetallic tool materials in, 336–340 properties of materials and, 327–330 specialty materials in, 338–340 Maxi-Mill vise, 285, 287, 291 maximum material condition (MMC), 127, 129 measuring fixture, 263–265, 264 mechanical treatment, 330 medium carbon steel, 331 metric conversion table, 345 millimeter and inch dimensioning, 118–122, 119, 120 milling fixture, 17 MITEE-BITE clamping system, 295–296, 296 modified angle-plate jig, 11–12, 12 modified angle-plate tooling, 189, 190 modular fixturing, 239 Modular Vise, 284–285, 289 modular workholding, 239–256, 240, 253, 254, 325 advantages for, 255 applications for, 250–255 clamping elements in, 244, 246–247, 246 constructing tooling for, 252–255 dowel pin systems in, 243–244, 245, 246 elements of, 253 locating and supporting elements in, 244, 246 master plate system in, 241–242, 243 mounting bases and plates in, 244, 246 multipart type, 255, 255 standard elements in, 244–246 subplate systems in, 240–242, 240, 241, 242 “T”-slot systems in, 242–243, 244 tooling form for, 251 welding operations and, 260–263 welding with, 252 modular-component workholding systems, 239 Mono-Bloc clamp, 296, 297 Multi Lok Vise, 285, 290 multipart modular workholding, 255, 255 multipurpose tooling, 101, 101 multistation fixture, 15 multistation jig, 13, 16 Multivise, 284, 288 nesting locators, 33–34, 218–219, 218, 219 nesting template jigs, 141, 141 nonferrous tool materials, 334–336 nonmechanical clamping, 53–60 nonmetallic tool materials, 336–340 note taking, 107 number of pieces required, 101 numbering system for steels, 331, 332 numerically controlled (NC) machines, 304–315 axes in, 304, 305 basic operations of, 304–305, 306 Cartesian coordinate system in, 305–307, 307 computer numerical control (CNC) in, 305 continuous path systems in, 308, 309 incremental and absolute programming in, 307–308, 307 perforated tape program for, 305, 305 point to point systems in, 308, 308 programming of, 304–305, 306 retrofitted systems in, 309, 309 tooling requirements for, 309 workholders for, 309–314 nuts and washers, 45, 46, 75–76, 75, 76 364 IndexOccupational Safety and Health Administration (OSHA), xii, 103 odd-shape clamping, 61 oil-groove bushings, 69 open jigs, 9 packing, in magnetic chucks, 54, 57 pallet decoupler unit, 233 palletized workholders, 313–314, 314 parallel blocks, 57 part and tool size relationship, 22–23, 23 part drawings, 2, 3 partial nest, 34, 34 parts lists, 92 perforated tape program for numerically controlled (NC) machines, 305, 305 pin locators, 29, 30, 218, 218 pivoting edge clamps, 247–248, 248 plain alignment pins, 80, 80 plain angle plate tooling, 189, 190 plain plate jig, 170, 170 planes of movement, 25–26, 25 planning tool design, 2–3 plastic resin, 337–338 plastics, 338 plate fixture, 13, 16, 155–158, 158, 159 cam clamps for, 158–165 clamping part in, 158, 160 cutter location in, 158, 161 design of, 156 locating part in, 156–158 supporting part in, 158 tool drawing of, 158, 162 plate jig, 11, 11, 170–188, 170 bushing location in, 173–176, 176 clamping part in, 173, 175, 176 designing, 171–177 initial design of, 176–177, 177 locating part in, 173, 175 supporting part in, 173, 175 tool drawing of, 177, 178 pneumatic clamps (See power [hydraulic/pneumatic] clamps) pneumatic collet chuck, 282, 282, 283, 284 point-to-point numerically controlled (NC) machines, 308, 308 power (hydraulic/pneumatic) clamps, 45, 46, 51, 52 accumulators in, 234 air assisted systems in, 232–234, 233 automatic sequencing in, 237 benefits of, 236 hydraulic clamps in, 234, 234 operation of, 235–236 pneumatic systems in, 234–235, 235 remote clamping using, 236–237 shop air in, 232 types of, 231–235 precast tool bodies, 67, 67 precision lathe fixture, 271, 272 precision-ground drill rod, 66 precision-ground flat stock, 66 predesign analysis, 100–102 accuracy requirements in, 101, 102 cutter requirements, type and size, 102 locating and clamping in, 101–102 machine tool requirements, type and size, 102 machining operations, type required, 101 material selection in, type and condition, 100–101 number of pieces required in, 101 sequence of operations in, 102 size and shape (overall) of part in, 100 preformed materials, 66–67, 89 press-fit bushings, 69, 69 primary burr, 72, 73 primary locator, 25, 27, 160, 212 procurement, 5 production drawings, 109–110 production plan, 2–3, 4 productivity versus tool cost, 90–91 profiling fixture, 15, 19 programming NC machines, 304–305, 306 Prohold Workholding Fixture, 274, 275, 276 projected tolerance zone (P), 129–130, 130 projection, 121–122, 122 Index 365properties of materials, 327–330 prototypes, 2 pump jig, 13, 15 purpose of tool design, 1–7 quick acting knobs, 47–48, 48 Quick-Change Kit, for Ball Lock, 302, 302 quick-release jig pins, 82 radius symbol, 130–131, 131 raised contact locator, 32, 32 reducing production steps and handling, 323–324, 324 reduction and enlargement ratios in, 121, 121 redundant locators, 151, 153 reference dimension, 131, 132 reference sheet, 104–105 referencing tool to work, 8, 9, 21 regardless of feature size (RFS), 129 relieved locators, 31, 31, 33, 151, 154 remote power clamping, 236–237 renewable bushings, 68 repeatability feature, 21 replaceable components, setup reduction for workholding and, 319 requirements of a tool designer, 5 resins (See also epoxy resin), 337–338 restricting movement, 25–26, 27 retaining rings, 76, 76 retrofitted numerically controlled (NC) machines, 309, 309 Richlite Fibre Laminate, 338–340, 339 ring nest, 33, 33 rise, in cam clamps, 161–164, 165 rotary jig, 13 rotary table fixture, 271, 273 round pin locator, 25, 27 S.A.F.E. ball clamp, 249, 250 safety and tool design, 103–106 sandwich jig, 11, 12, 171, 172, 181–184 screw clamps, 47, 47 screw edge clamps, 247, 248 screws, 73–86 secondary burr, 72, 73 secondary locator, 25, 27, 151, 153, 160, 212 secondary operations, economics of design and, 90 self-locking jig pins, 81–82, 82 sequence of operations, 102 serrated bushings, 69–71, 70 set blocks, 72–73, 74, 156, 224 set screws, 74, 74, 75 setup gauges (See set blocks) setup reduction for workholding, 316–326 benefits of, 316–317 cast and forged parts in, 320, 320 locating and, 317–318 material selection and, 321–322 redesigning for, 318–319, 318, 319 reducing production steps and handling in, 323–324, 324 replaceable components in, 319 simplicity of design and, 321, 321 standardization and, 322–323, 323 tolerancing and, 317–318, 322 workholder design and, 324–325 workpiece design and, 317–320 workpiece processing and, 320–324 shank type locator, 29 shape memory alloys/actuators, 59 shear strength, 330, 330 shop air, power (hydraulic/pneumatic) clamps and, 232 SI drawings with U.S. customary cross references, 118–119, 119 sight bracket, 225, 228 sight locators, 36, 36 simplicity of design, 89, 321, 321 simplified drawings, 90, 110–115 single jig plate, 221, 221 size and shape (overall) of part, 100 size dimensions, 117, 117 sketch development, 115–116 sketching, 107 sliding clamp, 45, 45 366 Indexslip renewable bushings, 68, 68, 195 slot clamps, 294–295, 295 slotted locator bushings, 80, 81 socket head cap screw, 74 solid supports, 28, 28 spacer bracket, 183, 186 spacer ring, 206, 209 special clamping operations, 60–61 special purpose bolts and nuts, 75–76, 76 special purpose bushings, 69, 70 specialty chucks, 271–275 specialty collet devices, 276–283 specialty materials, 338–340 specialty vises, 284–292 specific fit, 118 specifications sheet, 106 spherical diameter symbol, 130, 131 spherical locator, 32–33, 32 spherical radius, 131, 132 spindle work stop, 286 spiral cams, 161, 163–165, 164 split contact locator, 32, 32 split pins locators, 35, 35 spring stop buttons, 36–38, 37 spring-locating pins, 36–38, 37 standard components, 89–90 standard parts descriptions, 114–115, 115, 322–323, 323 statistical process control (SPC), xi steel, 65 step chucks, 275 step locator, 193 stereolithography, 2 stops, 28 straddle-milling fixture, 17, 155, 155 straight SI drawings, 119–120, 120 strap clamp, 43–47, 44, 45, 154 strap clamp and block, 310 strap support, 220, 223 structural steel sections, 66–67, 67 subplate systems, modular workholding and, 240–242, 240, 241, 242 subplates, 310, 311 supervision, 4 supplement gauges, 265–266 supplementary symbols, 126–132, 129, 131 support and locating principles, 21–40 angle plate jig, 189, 190, 193 leaf or sandwich jig, 183–184, 184 modular workholding and, 244, 246 plate fixtures, 158 plate jig and, 173, 175 power (hydraulic/pneumatic) clamps and, 236, 237 table jig, 177–180, 180 vise-held fixtures, 154 surface condition, in heat treatment, 341, 341 swing clamps, 47, 47 Swiveljaw, 292–293, 293 symbols used in drawings, 112, 112, 122–123, 123, 124–128, 126–132, 129, 130, 131 T pins, 80, 82 “T”-slot clamps, 294–295, 295 “T”-slot systems, modular workholding and, 242–243, 244 table jig, 11, 11, 171, 171, 177–181 bushing location in, 180 design of, 177–181 initial design in, 180–181, 181 locating part in, 177, 180 supporting and clamping part in, 177–180, 180 tool drawing for, 180, 182 tacking jigs and fixtures, welding operations and, 257–258, 259 tapered locators, 30, 30 template bushings, 69, 70 template gauges, 266, 268 template jigs, 9, 10, 139–149 bushing locating in, 142–145, 144, 145 design application for, 146 design procedures for, 141–146 initial jig design in, 145–146, 146 part locating in, 142, 144, 145 tool drawing for, 146, 147, 148 templates, drawing, 112–114, 113 Index 367temporary workholders, 325 tensile strength, 330, 330 Terrific 30 clamp, 296, 297 tertiary locators, 160, 212 thermal treatment (See heat treatment) thread inserts, 74–75, 75, 339 throw, in cam clamps, 161 toggle clamps, 49–52, 51, 259 tolerance, 22–23, 22, 90, 117, 117, 121–123, 122 geometric tolerancing in, 122–126 geometrically dimensioned and toleranced, 132, 133 projected tolerance zone (P) in, 129–130, 130 setup reduction for workholding and, 317, 322 tombstones, 310, 311 tool bodies, 65–66 tool design, 1–7 challenges of, 3–6 design phase in, 5 inspection phase in, 6 planning the design, part drawings, production plan in, 2–3 procurement in, 5 requirements of a tool designer and, 5 supervision in, 4 tool drawings, 109–138 computers used in (See also Computer Aided Design), 132–134 datum reference in, 122–126, 128, 129 dimensioning in, 116–118, 117 drafting sheets in, standard, 121 dual dimensioned drawings in, 118–122, 119, 120 feature control symbols in, 122, 122, 130 geometric characteristics symbols in, 122–123, 123, 124–128 geometric dimensioning and tolerancing in, 122–126, 132, 133 initial drawings in, 115–116 least material condition (LMC) in, 127–129, 129 maximum material condition (MMC) in, 127, 129 millimeter and inch dimensioning in, 118–122, 119, 120 number of views necessary in, 112 plate fixture, 158, 162 plate jig, 177, 178 projected tolerance zone (P) in, 129–130, 130 projection in, 121–122, 122 reduction and enlargement ratios in, 121, 121 regardless of feature size (RFS) in, 129 SI drawings with U.S. customary cross references in, 118–119, 119 sketch development in, 115–116 standard parts descriptions in, 114–115, 115 straight SI drawings in, 119–120, 120 supplementary symbols in, 126–132, 129, 131 symbols used in, 112, 112 table jig, 180, 182 template jigs and, 146, 147, 148 templates, guides, CAD libraries and, 112–114, 113, 114 tolerance and allowance comparison in, 121, 122 tolerance values in, 122–123 vise-held fixtures, 155, 157 words used on, 112 tool forces, 42 tool relationships, 115 tool steel, 332–334, 333 tooling alternatives, 107 toolroom, 3, 5 torque wrenches, 310 total indicator reading (TIR), 265 total savings calculation, 94 toughness, 327 Triple Precision Mount Vise, 285, 290 trunnion jig, 13, 15 tumble jig, 12, 13 turning fixture, 271, 272 turnover type welding fixture, 259 Twin Lock Workholding System, 287–288 كلمة سر فك الضغط : books-world.net The Unzip Password : books-world.net أتمنى أن تستفيدوا من محتوى الموضوع وأن ينال إعجابكم رابط من موقع عالم الكتب لتنزيل كتاب Jig and Fixture Design رابط مباشر لتنزيل كتاب Jig and Fixture Design
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