[BRLTTY] who of us know USB HUB, which charges connected devices and also connected Android device

[Mgr. Janusz Chmiel]

Please does somebody of us know special USB HUB, which charges devices, 
which are directly connected to it and which can also charge connected 
Android device by using MICRO SUB cable to it.
Why some manufacturers did not made such devices?
Today, user is being forced to buy expensive tablets, which contain jack 
to connect AC adapter and standalone USB Micro connector is separated.
But those devices are not cheap. Sure, some of them even contain build 
in keyboard.
Why those HUBS, which charge connected devices to it and also Android 
device do not exist?