Figure Dimensions

Patent applications usually include drawings that show example shapes, positioning, etc. Prior-filed patent applications are the primary source of prior art used by Examiners to reject new applications. Often, Examiners rely purely on the figures as showing certain claimed features, sometimes using a ruler to measure elements in the drawings to show claimed relative dimensions. However, such actions are often improper.

A recent example is illustrated in US 13/457,653. The invention relates to a casement window fall
prevention device with an emergency escape release mechanism. Claim 1 requires a specific relative dimension in terms of several components, including:

an escape disengagement opening in a bottom side of said track and positioned outwardly beyond said outer limit stop and dimensioned to pass said roller for thereby disengaging said
roller from said track by first forcing said roller beyond said outer limit stop and then downwardly through said disengagement opening with hand manipulation of said limit arm by an operator.

The Examiner took the position that completely retracting the release stop in the prior art (Runk) yields a space in the track wide enough to insert and remove the roller from a vertical direction based on assumptions with respect to the structure and dimensions of the prior art’s frame track and release assembly shown in the drawings.  Namely, the prior art did not disclose any relative dimensions of the various components and thus while the drawing as shown may look as if it had the claimed dimensions, the PTAB ruled that it was not possible to actually determine whether the roller could engage (or disengage) the track.  The Board noted that:

To the extent that the Examiner relies on Runk’s figures ... we note that Runk does not provide that the figures are drawn to scale, and, therefore, it is too speculative in this instance for us to rely on the relative dimensions ... depicted in the figures as evidence to support the Examiner’s finding.

Case law makes clear that patent drawings do not define the precise proportions of the elements and may not be relied on to show particular sizes if the specification is completely silent on the issue, and that absent any written description in the specification of quantitative values, arguments based on measurement of a drawing are of little value.