I claim the ornamental design for a ball safety latch lock, as shown and described.
FIG. 1 is a right side anterior perspective view of a ball safety latch lock.
FIG. 2 is an anterior view of a ball safety latch lock.
FIG. 3 is a posterior view of a ball safety latch lock.
FIG. 4 is top view of a ball safety latch lock.
FIG. 5 is a bottom view of a ball safety latch lock.
FIG. 6 is a left side view of a ball safety latch lock; and,
FIG. 7 is a right side view of a ball safety latch lock.
The dash dot dash lines shown in FIGS. 1-2, and 4-7 of the ball safety latch lock that are immediately adjacent to the claimed lines of the knob and latch features are the boundary of the design. The dash dash broken lines shown in FIGS. 1-7 are for the purpose of illustrating environment. None of the broken lines form any part of the claimed design.