A manually activated seat belt device comprising: a latch plate (20) and cooperating buckle (100). The latch plate comprises: a tongue (22) lockingly engaging a cooperating part of a seat belt buckle (100) and a second part (26) having a seat belt clamping surface (30) adjacent a belt receiving opening (28) within the second part, walls (32) extending about opposite sides of the opening (28), a yoke (40) slidably received upon the latch plate (20) above the opening and slidably positioned against the walls of the second part, a clamping bar (48), wherein the seat belt (90) is inserted through the first opening (28) between the belt clamping surface and the clamping bar; a clamp initiating mechanism (60) manually movable from a cinching position to a clamping or locking position, including a cam surface (63) which when moved to the cinching position urges the clamping bar toward the clamping surface to thereby clamp the seat belt therebetween, wherein the buckle includes a recess to receive a locking tab to maintain the mechanism (60) in its locking position and for releasing same.