Invention study 02 / Hand tools

A Wrench That Changes Size

A question raised while working on a car: could one closed-end wrench fit multiple hexagonal fastener sizes without the familiar trade-offs of an adjustable open-end wrench?

Genuine blue and green 3D-printed wrench prototype with an adjustable six-jaw hexagonal head — One early 3D-printed prototype, used to explore the six-jaw arrangement.

Actual black 3D-printed adjustable wrench head prototype with six intersecting jaws — **01 · Printed mechanism**A second prototype showing the hexagonal opening.

Authentic Figure 1 drawing from US Patent 12,036,639 showing the wrench — **02 · Patent Figure 1**Wrench design as illustrated in the issued patent.

Authentic Figure 14 drawing from US Patent 12,036,639 depicting a socket variant — **03 · Patent Figure 14**An illustrated socket embodiment from the patent.

Source: inventor's prototype photographs and actual drawing plates reproduced in the inventor's earlier patent materials. View the full issued patent for authoritative detail.

The starting point

An unsatisfying experience using an adjustable wrench on a car led to a closer look at how a tool could grip a hexagonal fastener. Inspiration also came from an unlikely place: the moving, iris-like panels of the roof at Mercedes-Benz Stadium.

The concept developed into a closed-end opening formed by six sliding jaws. In the patented design, those jaws move within a retainer to vary the size of the fastener-receiving opening.

Working through the idea

Large-scale 3D-printed prototypes were used to explore the motion. Feedback received while investigating licensing led to an additional ratcheting feature. The patent covers the adjustable fastener-engaging mechanism.

The invention remains separate from a mass-produced commercial wrench. The published patent documents the approach; it doesn't establish the performance or durability of a finished consumer product.

The public record

The diagram uses constant rigid jaw profiles translating along straight guides to convey the patent’s chain reaction. It is not a substitute for the issued mechanical drawings.

Read the published patent and view drawings ↗