28 November 2023


The High Court found Mayborn’s (Tommee Tippee) Made For Me breast pump (“MFM pump”) did not infringe Chiaro’s (Elvie) UK registered designs. Once the features dictated by the technical function were removed, the Court found notable differences in the MFM pump, which resulted in a different overall impression and therefore no infringement was found.


A registered design holder has a monopoly over the use of that design and any other design that does not create a “different overall impression” on the informed user.

When comparing the contested design against the registered design(s), the Court must identify: (i) the sector to which the designs belong; (ii) the informed user; (iii) the designer’s degree of freedom; and (iv) assess the outcome of the comparison taking into account (i) – (iii). When assessing whether a product creates a different overall impression, the Court must disregard features of appearance of a product which are solely dictated by the product's technical function.

Three of Chiaro’s UK registered designs were incorporated into its product called the “Elvie pump”: (i) the pump as a whole (ii) the pump housing design, and (iii) the milk collection vessel at the base of the pump. The Elvie pump, in contrast to the existing breast pumps on the market, has integrated milk collecting apparatus (and has been designed to be worn inside a bra), rather than having separate tubes and a milk collecting vessel. 

Chiaro asserted that there are many ways to design a breast pump and given that high degree of design freedom; the more similar the products, the more likely it is to be infringing. It also sought to define the design corpus widely, to include manual and electric breast pumps to illustrate the similarity of the look and feel of the contested product with the registered designs. Mayborn on the other hand, sought to define the design corpus narrowly so that the differences in the product would be more apparent.

Mayborn’s defence centred on excluding important features of Chiaro’s registered designs as being dictated purely by function. Further, it sought to rely on Chiaro’s patent for the Elvie pump to support its case that certain features of the registered designs were purely functional.


The High Court decided that the MFM pump did not infringe any of the registered designs. In reaching this decision, the Court held:

  • The correct sector (which the Court establishes to help define the relevant informed user) was electrical breast pumps and not, as Chiaro had suggested, the wider ‘breast pumps’ sector, which would have included manual pumps.
  • The informed user in this case would be one with a relatively high level of attention to detail who will be particularly attentive to how it appears and handles.
  • The correct starting point when considering constraints imposed on the designer by technical functions was the design itself. This approach would avoid “wider, ill-defined, constraints” arising from the wider design corpus.
  • Authorities allowed reference to a physical embodiment of the designs (i.e. the Elvie pump product itself) provided that the embodiment used conformed to the designs.
  • Patents (including the claimant’s own patents) can be included in the design corpus and used as objective evidence (but not conclusive evidence) of the functional aspects of the designs when considering the exclusion for technical function.
  • Several features (the curved outer and inner facing shapes of the pump and the location, transparency and shape of the milk vessel) of the registered designs were solely dictated by technical function and as a result, were excluded from the assessment.
  • Once these features had been excluded, the differences between the remaining aspects (the chunkier design, the scallops and dips on the front of MFM pump) created a different overall impression with the registered designs.

Key takeaways

This case contains some useful guidance to consider when defining the sector and design corpus to set the context for assessing infringement, including to what extent patent evidence can be used. It is interesting to note that the claimant’s own patent evidence can support an argument on the technical functions of a product but is not necessarily conclusive evidence.

In cases such as these, it is an important reminder that registered designs only protect the aesthetics of a product, rather than its function and interface with the wearer.

For more information or if you have any questions, please contact Emily RobertsHolly Webb or your usual IP team contact.

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Key contact

Emily Roberts

Emily Roberts Partner

  • Intellectual Property and Media
  • Intellectual Property Disputes
  • Intellectual Property Portfolio Protection

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