US Patent 9339928 Mechanic's creeper

A creeper (10) includes a frame (11) having spaced side rails (12) and cross rails (13) extending between the side rails (12). A pad (28) is carried by the cross rails (13) and is spaced from each side rail (12). Each side rail (12) has end portions (14, 15) which carry a caster assembly (17), and the cross rails (13) are positioned closer to each other than the caster assemblies (17) are from each other. Each side rail (12) also includes a raised portion (26) which is higher than the end portions (14, 15) when the caster assemblies (17) are on a surface, and a lower portion (23) which is lower than the end portions (14, 15) when the caster assemblies are on a surface.