Answer:
The gravitational force does change believe it or not, but the explanation for this is that the Earth's orbit is an oval (or circle) the closer it nears itself to the Sun. The Sun's gravitational pull pulls the Earth to it, bringing it closer and as it reaches the other side, let's call this L; When it reaches L, it becomes the same gravitational pull reset as A is, and another section over the Sun, lets call this M; and when it reaches M, its the same pull as B.
