The state of the art in the field of transducers and tyre deformation measurement methods tells of the high importance of this issue. The “tyre deformation” may be analysed from the point of view of both the global deformation of the tyre structure and the local deformation of single tread lugs. So far, there is no all-purpose transducer that would be capable of identifying simultaneously all the tyre deformation components that would be interesting for researchers in all the above aspects. If it is considered sufficient to define the tyre deformation by the value of displacement of a selected tyre point in relation to the wheel rim, then the deformation can be measured with the use of a device built in accordance with the original concept presented in this article, i.e. a mechanical contacting transducer. The transducer is intended to measure the tyre deformation by separately determining the three principal (tangential, lateral, and radial in relation to the wheel disc) deformation components, which are to be recorded at the same time. The article presents a general mathematical model of the device, with highlighting the diversity of methods of describing the model in a formal way and illustrating them by possible examples. Illustrative different paths of implementing the concept of the device have been shown as well. A measuring device built in accordance with the idea may constitute a tool for identifying the mechanical tyre characteristics, which might be then used inter alia as input data at simulation research on vehicles, e.g. for modelling the vehicle body vibrations or for analysing the energy absorption at vehicle motion.