A product with consumable or replaceable parts can be complicated to patent. These kinds of products have a reusable base component and replaceable widgets that work with it. Think razor handles with disposable razor blades, coffee brewers with coffee pods, or table saws with replaceable blades. Sales of the widgets may create a substantial revenue stream, but what’s to stop an interloper from copying the widgets and undercutting these continuing sales? Patents! Right? Maybe; as long as you’ve been careful to patent the right aspects of your products and to avoid running afoul of the patent exhaustion doctrine. This doctrine “exhausts” a patentee’s patent rights in a product after it has been sold. The exhaustion is expansive. Courts have held a method claim automatically exhausted by the exhaustion of an apparatus claim in the same patent. Very recently, the Supreme Court may have expanded the doctrine about as far as it can go: now all patent rights are exhausted regardless of any attempt at post-sale restriction, and regardless of the location of the sale. In other words any sale, anywhere, exhausts all patent rights in the sold product.
Suppose you run a prolific company that makes coffee brewers that use single-serve disposable pods and also makes table saws with replaceable blades. For each product your business model might depend on controlling the pods or blades used with your product. For instance, if you take a loss on your coffee brewer intending to make up for it in sales of coffee pods, a patent covering the pods may be more valuable than one covering the brewer. If you intend to develop a licensing program for third-party saw blades, a patent covering a saw blade’s interface with your table saw may be crucial. So how might one breathe more easily despite the patent exhaustion doctrine to keep infringement claims viable? Here are some suggestions.
Patent your widgets separately. If patented together with the base component you may not be able to escape exhaustion of your patent claim, since your sale of the base component may “exhaust” your rights in the claim with respect to that sale. By patenting the widget separately—and in a separate patent—there is less chance of its claims being exhausted by sale of the base component. Keeping your widgets separate also minimizes your exposure to other pitfalls, such as being limited to contributory infringement claims.
Patent with your design strategy in mind. A robust design patent strategy can be a great tool to prevent knock-off widgets from cutting into market share. Strategic claim drafting in a design patent can in many cases provide claim scope broad enough to cover unauthorized widgets of varying configurations that may work with the base component. This is accomplished through the creative use of solid and broken lines in the drawings to claim particular aspects of the widget design, so long as the design of these aspects is not dictated by their function. This strategy can be especially helpful where it may be difficult or time-consuming to get a utility patent claim broad enough to stop knockoff widgets. And because your design patents will be directed to the widgets themselves, they are unlikely to fall victim to exhaustion due to sale of the base component.
Design with your patent strategy in mind. Designers may find it useful to over-design the parts of the base component and the widget that interact, with two additional goals in mind: (1) at least the widget side of the interaction should include a standalone novel feature, whether functional, ornamental, or both; (2) the interaction should only properly work with a widget including the novel feature. This may provide the opportunity for strong and specific utility or design patent claims directed to the widget that can be used to prevent unauthorized knockoff widgets.
Make your widgets disappear. Now that the Supreme Court has in some ways sanctioned unauthorized re-use of spent widgets, patents may not stop a competitor from re-filling and re-selling them. But what if there’s nothing left to re-fill? If possible, consider making your entire widget consumable by the base component or making it only survive a single use intact, so that it is not re-fillable and a customer will be left to simply recycle the remainder.
These suggestions can augment a careful patenting strategy to help combat crafty interlopers and circumvent courts’ hostile stance toward downstream control of products after their sale. A strategic combination of product design and intellectual property law can be a key tool in protecting investments in developing such products. A bold, full-bodied patent prosecution strategy can help cut through the unique difficulties in protecting investment in products that use consumable parts. Involving your patent counsel in the early stages of product design can be the difference between a sale that exhausts your patent rights, and one that leaves the company buzzing with viable patent protection that rips through the competition.
 See Keurig Inc. v. Sturm Foods, Inc., 732 F.3d 1370 (Fed. Cir. 2013).
 See Impression Products, Inc. v. Lexmark International, Inc., 15-1189 (May 30, 2017).
More legal analysis is available at The National Law Review.