Thill Couplings Patents (Class 278/52)
Resilient (Class 278/53)
Safety attachments (Class 278/54)
Plural (Class 278/55)
Special-position release (Class 278/56)
Removable transverse pin or bolt (Class 278/60)
Opposed lug engaging or carrying jaws (Class 278/66)
L-head type (Class 278/67)
T-head type (Class 278/68)
D-head type (Class 278/72)
Ball and socket (Class 278/80)

There are no patents to show for this class.