A football helmet includes a plastic shell with side regions having an ear flap with a face guard connector, an ear opening, a slot, and a snap connector. The helmet also includes an internal padding assembly removably connected to the plastic shell and including a jaw pad with a force attenuating layer. When the helmet is worn, a front edge of the jaw pad is positioned both in front of a coronal plane and below a basic plane of a head of the helmet wearer. A chin strap assembly releasably secures the helmet to the wearer and includes a lower flexible strap extending outwardly from each side of a central protective member. When the helmet is worn, an extent of the lower flexible strap is received by the slot when said strap is affixed to the snap connector. The shell also includes a raised central band integrally formed as part of the shell and extending across the crown region to the rear region. An arrangement of elongated vent openings flank the raised central band.

A tolerance ring has a hollow band with outwardly extending corrugated protrusions forming waves that engage an inner surface of a bore of a housing. At one end of the tolerance ring is an inwardly flared guide surface extending axially and radially from the band. The guide surface acts as a tapered entrance to assist the insertion of a shaft into the hollow band during assembly of the ring into the bore of the housing.

A bed comprises a fixed width deck section, a wing movably coupled to the fixed width section, and a rack and pinion mechanism for extending and retracting the wing.

A bed comprises a fixed width deck section, a wing movably coupled to the fixed width section, and a rack and pinion mechanism for extending and retracting the wing.

A constant volume flexible joint system includes a flexible membrane for coupling across a joint and spaced radial support ribs fitted to the membrane. Axial support structures are coupled to the spaced radial support ribs preventing axial deformation of the joint due to a differential pressure. The axial support structure preferably include pivoting sockets and blocks enabling the joint to flex and the flexible membrane to contract on the inside of a bend and expand by an equal or near equal amount on the outside of the bend resulting in a constant volume joint that requires low or no torque throughout the bending motion.

A tolerance ring has a band with outwardly extending corrugated protrusions forming waves that engage an outer surface of a shaft. At one end of the tolerance ring is an inwardly flared guide surface extending axially and radially from the band. The guide surface acts as a tapered entrance to a bore of a housing to assist during assembly.

A football helmet includes a plastic shell with side regions having an ear flap with a face guard connector, an ear opening, a slot, and a snap connector. The helmet also includes an internal padding assembly removably connected to the plastic shell and including a jaw pad with a force attenuating layer. When the helmet is worn, a front edge of the jaw pad is positioned both in front of a coronal plane and below a basic plane of a head of the helmet wearer. A chin strap assembly releasably secures the helmet to the wearer and includes a lower flexible strap extending outwardly from each side of a central protective member. When the helmet is worn, an extent of the lower flexible strap is received by the slot when said strap is affixed to the snap connector. The shell also includes a raised central band integrally formed as part of the shell and extending across the crown region to the rear region. An arrangement of elongated vent openings flank the raised central band.

A tolerance ring has a band with outwardly extending corrugated protrusions forming waves that engage an outer surface of a shaft. At one end of the tolerance ring is an inwardly flared guide surface extending axially and radially from the band. The guide surface acts as a tapered entrance to a bore of a housing to assist during assembly.

A system and method for increasing a tooth shear strength without also increasing a torsional rigidity of a flexible sleeve disposed between two hubs of a flexible coupling for transmitting mechanical motion between two shafts includes attaching a stiffening caps to both ends of a flexible sleeve, between the flexible sleeve and the hubs.

A football helmet includes a plastic shell with side regions having an ear flap with a face guard connector, an ear opening, a slot, and a snap connector. The helmet also includes an internal padding assembly removably connected to the plastic shell and including a jaw pad with a force attenuating layer. When the helmet is worn, a front edge of the jaw pad is positioned both in front of a coronal plane and below a basic plane of a head of the helmet wearer. A chin strap assembly releasably secures the helmet to the wearer and includes a lower flexible strap extending outwardly from each side of a central protective member. When the helmet is worn, an extent of the lower flexible strap is received by the slot when said strap is affixed to the snap connector. The shell also includes a raised central band integrally formed as part of the shell and extending across the crown region to the rear region. An arrangement of elongated vent openings flank the raised central band.