A common issue in patent prosecution is the requirement for the drawings to show all claimed features. As claims are amended during prosecution, sometimes features that were thought to be "secondary" turn out, in hindsight, to be fundamentally key in defining over the prior art. This is why it is so important to make sure that complete drawings are included with an initial application that show all of the features described therein.

37 CFR 1.83(a) states that the drawings in a nonprovisional application must show every feature of the invention specified in the claims. However, conventional features disclosed in the description and claims, where their detailed illustration is not essential for a proper understanding of the invention, should be illustrated in the drawings in the form of a graphical drawing symbol or a labeled representation (e.g., a labeled rectangular box).

This means that even if the specification has proper support (under Section 112), one cannot claim that features unless it is shown in the drawings.

Sometimes, even when the drawings do show all that is required, examiners with a bias toward rejecting applications (improperly) use Rule 83(a) to make life needlessly difficult for applicants.  Specifically, some examiners are under the mistaken impression that the rules require every feature in a claim to be shown in a single drawing. Likewise, some examiner argue that if there was a restriction requirement, then the non-elected figures cannot be used to satisfy Rule 83(a). The CFR dispels these notions by making clear that it is the "drawings" (plural) that must show every feature of the invention specified in the claims, not a single drawing, and not just the drawings drawn to the elected species.

Here is an example of language used by an examiner to object to drawings along the above lines:

And here are some relevant figures, where FIG. M was elected, meaning that FIG. I was a non-elected figure. The claims were drawn to the louvered plate spacing in FIG. M, but of course FIG. M only shows the louvers as rectangular boxes whereas FIG. I showed them isometrically:

So what do you do if you encounter an examiner who simply (improperly) maintains drawing objections? You cannot appeal this issue, as it is an objection. Rather, you must petition, generally under under 37 CFR 1.182, for a decision on a question not specifically provided for. In the above example, the petition pointed out several problems with the examiner's approach.

First, the examiner’s assertion that FIG. M “doesn’t show any louver plates” was not supported by the evidence of record. While FIG. M utilized rectangular boxes to show varying sizes of the louvers, it was a two-dimensional drawing serving to show one particular aspect of the feature, namely the varied nature of the plate dimensions, and as such did not show as clearly as a 3-D drawing the louvered baffle. But that does not in any way negate the features shown in the drawing. Further, nowhere in the description of FIG. M was there described the absence of the louver plates. Second, even if FIG. M did not show the louvers in 3-D, the louvered baffle was found within the other figures, including FIG. I.

Furthermore, the idea that only the elected features can be used to meet the requirements of Rule 83(a) is nonsensical and leads to absurd results. One cannot possibly predict how the USPTO examiners will restrict the application, and so that would essentially mean that every figure of every application would need to show every possible claimed feature. 

So, if you find an examiner requiring more than what is set forth in Rule 83(a), consider petitioning the Office under 1.182 to confirm what is actually required to be shown in the drawings.