Microsoft doesn't reveal whether it plans to launch a Surface Phone in future or now, we often come across patents for such kind of devices.
Likewise, a recently discovered patent filed by Microsoft shows a device featuring a so-called self-regulating hinge. This is something the Surface Phone has been rumored to use. With this hinge, two separate displays would seamlessly become one enabling the Surface Phone to do more than just a smartphone. We are not really surprised as this is the main idea that comes behind Microsoft's Surface lineup.
One of the drawings included in the patent document shows the Surface Phone featuring a keyboard so that it can be used like a small-sized notebook. Another image shows an alarm clock kind of form factor that could also function as a tablet.
The patent further describes a "pair of self-regulating hinge assemblies rotatably securing hinge ends of the first and second portions around a first hinge axis associated with the first portion and a second hinge axis associated with the second hinge axis so that an extent of rotation around the first hinge axis corresponds to an extent of rotation around the second hinge axis."
Of course, just because a patent has been filed, it doesn't mean the device will actually see the day light. There has many instances where companies file patents for a particular device or a technology, but forget all about it later on. Also, it doesn't work out the way it was imagined in reality.
That being said, rumors have it, Microsoft is working a Surface Phone that would use a Courier-like form factor with connectivity options like LTE. In any case, if any such phone get launched eventually it would not run Windows 10 as the company has already announced no major updates will be made to the operating system.