Start by forming a piece of gold plated metal mesh into a conveyer belt.
On one side of the device, a hopper dispenses ground coffee onto the conveyer.
In the middle region of the device, a series of nozzles drip hot water onto the coffee. This liquid goes through the coffee, through the conveyer,
into a funnel, and into the carafe.
On the other side of the device, as the conveyor goes around one of the rollers holding it in place, a scaper transfered the used grounds from the belt into a chute, where it slides into a container for later disposal.
To keep the coffee centered on the belt, and to prevent the water from washing the ground coffee off of the belt (and possibly into the carafe), two vertical pieces of plastic, run the length of the conveyor. The coffee sits inside the trough created by these plastic pieces and the belt.
To keep the belt from sagging, two more pieces of plastic are used, located below the conveyor belt, lined up with the plastic pieces above the belt.
Brew strength can be adjusted in either of three ways.
First, the rate at which coffee is dispensed from the hopper onto the conveyor belt can be adjusted.
Second, the rate at which the belt moves can be adjusted.
Third, by causing a controlled amount of hot water to bypass the coffee grounds and mix with the coffee. I would *not* use this myself, but I've noted that the "brew strength" selector on my drip coffeemaker uses this technique. I always set the machine to strong (no dilution), but I suppose someone out there must like watered down coffee, or the feature wouldn't exist.