Mechanic's creeper construction

Claim 1

A mechanic's creeper comprising, in combination: a molded plastic creeper platform, a plurality of wheels attached to said platform adjacent the periphery of said platform; said platform having a generally rectangular plan view configuration and including a head end, a foot end and a longitudinal centerline axis extending from the head end to the foot end of the platform, said platform formed as a single hollow molded plastic unit and having a top surface layer and a bottom surface layer of plastic, said top layer being generally smooth on the outside and the bottom layer including a plurality of indentations projecting toward and contacting the top layer to enhance the rigidity of the platform with the space between the layers being otherwise hollow; the top layer having a surface profile which changes along the longitudinal axis and includes at least three distinct and connected sections joined to a head section at said head end, said three distinct and connected sections comprising: (a) a shoulder section adjacent the head end and extending axially from said head section, said shoulder section being generally flat transverse to the axis across the width of the platform; (b) a lumbar support section axially adjacent the shoulder section and positioned toward the foot end, said lumbar support section elevated relative to the shoulder section, but not relative to the head section and including curved side lumbar support portions on each side of the axis; and (c) a buttocks section axially adjacent the lumbar support section and which is not elevated relative to the connected lumbar support section, said buttocks section curved to conform to human buttocks, said curvature extending transverse to the axis and extending from adjacent the lumbar support section to the foot end of the platform; a transition section intermediate each of the three sections and said head section to effect continuous connection thereof; flat planar sections along the side edges of the platform at the head end, lumbar support section and foot end, said planar sections being co-planar and including equally sized wheels, said wheels attached thereto for uniform platform support; said head section adjacent the shoulder section being a generally flat planar section coplanar with the planar sections and elevated relative to the shoulder section, said head section including a head support cushion; and said bottom surface layer indentations comprising a plurality of longitudinal indentations arranged in rows parallel to the axis, said indentations extending from the bottom surface layer to the top surface layer to mechanically stabilize the platform, said indentations having a longitudinal length in the range of ⅙ to ¼ the width of said indentations said indentations of adjacent longitudinal rows overlapping longitudinally, said indentations of each row being spaced longitudinally, said adjacent rows of indentations being generally equally spaced, and the width of each indentation being substantially equal to the spacing of the top layer and bottom layer in the region between indentations.