A latch mechanism selectively retains a first assembly to a second assembly. The first and second assemblies are configured for sliding engagement along an engagement axis. The latch mechanism includes a latch shaft mounted to the first assembly to rotate about a latch shaft axis, a torsion spring to bias the latch shaft relative to the first assembly, and a transverse latch member coupled with the second assembly. The latch mechanism is configured to automatically latch in response to the first assembly being pushed toward the second assembly. The transverse latch member interacts with the latch shaft to rotate the latch shaft in a first direction in response to movement of the first assembly toward the second assembly. Further motion of the first assembly toward the second assembly results in rotation of the latch shaft opposite to the first direction into a retention configuration that retains the transverse latch member.