each pins 152 is prevented from falling into the interior 122 by its engagement with rear end tip 181 of the inner actuating sleeve 172 and in case of a pin breaking by projection 196 formed at the end of each hole 150 in housing 32 while in the preferred embodiment projections 196 are discrete projections each one separate from the others these projections could be joined to form for example an annular rim the various shape of pins 152 produces various surfaces which enhance the operation of socket 112 since all pins 152 are identical only one pin will be described in detail surface 156 is normal to axis 154 and adjacent surface 138 on the pin 39 s cylindrical wall the latter surface engaging shoulder 137 of plug member 113 when the socket is in a locked configuration surface 138 is engaged by surface 137 of the plug member as will be understood below surface 158 is angled with an angle 200 relative to the normal to axis 154 in order to produce a compact quick coupling design to minimize the outside diameter of outer sleeve 174 and to prevent rotation of pins 152 about their axes it is necessary to prevent pin.