Wood Pattern-Making by Horace Traiton Purfield explains the principles and elementary practice of making wooden forms for cast metal. Published by the author in 1906, it includes an appendix on the care and use of woodworking bench tools. Purfield’s title-page role is instructor in woodwork and pattern making in the University of Michigan’s Department of Engineering.
Understanding what a pattern must do
The introduction defines a pattern through its relationship to a sand mold and the casting produced in that mold. This immediately distinguishes pattern-making from making a finished wooden object. The wooden form has to serve another process, and its requirements cannot be judged by its appearance alone.
Purfield’s preface describes the book as an elementary text for technical and manual-training students. He also wants engineers and draftsmen to understand the fundamental principles well enough to design patterns that can be made efficiently. The volume therefore links workshop execution with the decisions made while preparing a design.
The author emphasizes that reading cannot replace practice. The examples are intended to explain principles and demonstrate methods of construction, giving the student a basis for approaching later work. That balance between explanation and actual making is central to the book’s educational purpose.
Molding, draft and shrinkage
The opening chapters cover molding and general principles before turning to materials. The discussion of draft explains why the sides of a pattern need a taper that allows withdrawal from the mold. The treatment of shrinkage connects the dimensions of the pattern with changes in the metal as it cools.
These subjects show why a pattern does not simply duplicate the final part at the same size. Its form has to take account of removal, material behavior and any machining that will follow casting. Readers studying old castings or manufacturing drawings can use the explanations to understand choices that otherwise seem arbitrary.
Materials, fillets and cores each receive separate attention. Fillets concern the meeting of surfaces, while cores create internal spaces that the outer mold alone cannot form. Their inclusion demonstrates how the wooden pattern participates in planning the whole casting, including portions that will not be visible from outside.
Parting, joints and different pattern types
The next chapters distinguish the molder’s joint or parting from constructional joints. One concerns how the mold is divided and the pattern withdrawn; the other concerns how the wooden form is assembled. Keeping these ideas separate helps clarify the relationship between foundry requirements and woodworking methods.
Special types of patterns and plate work with irregular parting extend the treatment beyond the simplest examples. The illustrations give the reader visible forms against which to follow the written explanation. The book is particularly useful when read with attention to the boundaries between pattern, mold and core.
The core-print discussion explains the importance of locating and supporting a core. A mistake in that part of the pattern can misalign an internal space or change the intended wall thickness. Such passages connect careful wooden layout with consequences in the later metal object.
Pulleys, gears, pipes and other examples
Dedicated chapters address pulley patterns, patterns for cast gears and pipe fittings. These examples introduce forms with rims, arms, teeth, bends or internal passages. They give practical settings for the earlier principles of draft, parting, assembly and core work.
Miscellaneous examples and stove pattern-making broaden the range further. The contents and list of illustrations are valuable guides to this part of the volume. Readers researching historical production methods can move from a general explanation to a recognizable type of component.
An appendix on bench tools
The appendix covers reading mechanical working drawings, lumber, pattern turning and woodworking tools. Planes, gauges, chisels, cutting wedges, boring tools and saws are among the subjects represented. The explanations supply the practical background needed to understand how the illustrated wooden forms can be made.
A discussion of the shrink rule is especially relevant to the pattern-maker. It shows how a measuring instrument can incorporate an allowance required by the manufacturing process. The tool appendix thus complements the foundry principles instead of functioning only as a general list of workshop equipment.
Who will find this book useful?
This free ebook suits pattern-making students, engineering historians, tool researchers and readers interested in the connection between woodwork and casting. It preserves a teaching approach that starts from the purpose of the pattern and develops toward specific constructions. Historical foundry and machinery practices require comparison with current standards before practical use. This scan is image-based without searchable text; the contents, illustrations and index are the main navigation aids.
Book details
- Author: Horace Traiton Purfield
- Publisher: Published by the author; printed by The Scharf Tag, Label & Box Co., Ypsilanti, Michigan
- Year: 1906
- Edition: No numbered edition stated
- Digital length: 227 PDF pages
- Language: English
- File size: 6.54 MB
