Patent drawing experts put much emphasis on dimensioning because it is one of the most fundamental elements of a patent drawing that should be done accurately and precisely. With this article we came up with do’s and dont’s of dimensioning in patent drawings which should be followed by people who are creating it irrespective of whether they are patent drawing experts or a newbie draftperson.
However, before we move ahead with the do’s and don’t’s of patent drawing we need to understand what dimensioning is in a patent drawing, so let’s define it first.
What patent drawing experts say about dimensions?
Dimensioning is an art of providing a clear and complete description to an object in patent drawings and/or technical drawings. Unlike visual arts wherein the artist has the liberty to let it get interpreted many ways, in drawings for patents we don’t have that liberty. A patent drawing should be drafted in such a way that it lets viewers interpret it in a single way only and not otherwise.
If patent drawing experts are believed then it should be done as per the engineering drawing guidelines put forth by various federal agencies like
Do’s and don’t’s of dimensioning in patent drawings
- Dimension should be given clearly so that it can be interpreted in only one way
- A draft person should avoid providing duplicated dimensioning means the same information be given in two different ways.
- Unnecessary dimensioning should be avoided means no dimension should be given except those needed to produce or inspect the part.
- No dimension should be given to hidden lines
- Dimensions should be given to finished surfaces or important centerlines in preference to rough surfaces wherever possible
- Dimensioning should be done in such a way that it will not be necessary for the machinist to calculate, scale, or assume any dimension
- Dimensions should be attached where the shape is best shown (contour rule)
- Dimensions should be placed in the views where the features dimensioned are shown as true shape
- Center lines should generally not extend from view to view
- Leaders for notes should be straight, not curved, and pointing to the center of circular views of holes wherever possible.
- Leaders should extend from the beginning or from the end of a note, the horizontal “shoulder” extending from mid-height of the lettering.
- Dimension figures should be approximately centered between the arrowheads, except that a “stack” of dimensions, the figures should be “staggered”.
- Dimension figures should be about 3mm (1/8″) high for whole numbers and 6mm (1/4″) high for fractions.
Properties of dimensions in a patent drawing
Patent drawing experts mention four properties those define whether a mentioned dimension is accurate or not, below are the properties:
Accuracy: correct values should be provided
Completeness: nothing must be left out, and nothing duplicated
Clearness: dimensions must be placed in appropriate positions
Readability: the appropriate line quality must be used for legibility
All we can say is that patent drawing is a structured and regulated document that should be created adhering to various rules and regulations put forth by the regulatory body. These rules should be followed by patent drawing experts as well as the newbie.