PURPOSE: To allow easy connection and releasing of attachments by providing first and second throats engaging with first and second crossbars of an attachment, and also providing a holding means which holds the second crossbar with the second throat.

CONSTITUTION: When attaching such attachments as bucket to a backhoe, etc., a crossbar 38 of an attachment is engaged with a throat 88A of a coupling device 10 connected to beams 20 and 22. When the device 10 rotates counter clockwise, a crossbar 40 rotates a pawl assembly counter clockwise. Then a pawl 186 of the pawl assembly rotates a secondary latch 162 of a latch member counter clockwise around a pivot pin 154 to move a primary latch upward, separating from a latch surface 138 of a wedge block to release the block. Further, the wedge block translates under the effect of a compression spring 130 so that a cam surface engages with the crossbar 40, resulting in tight engagement with a throat 92A.