An inkjet printer has a print bar system comprising a print bar and a plurality of selectively replaceable print heads attached to the print bar. The system comprises a receptor on the bar, for installation of a print head, each print head having a rear face for insertion in said receptor in a first direction. A latch is provided, pivoted on the bar. The latch has a user-actuatable handle adapted, during a first movement thereof, to engage a latch member of the latch with a catch on the bar to lock the latch in a lockable position on the bar. A platform is mounted on the latch with freedom to move with respect to the latch in said first direction when the latch is in said lockable position. The platform has a latch electrical connector, adapted to engage a head electrical convector on the print head, by mutual movement of the connectors in said first direction. A bias means urges the platform in said first direction. A second movement of the handle releases the platform for movement relative to the latch under the action of the bias means. When the latch is in the lockable position, and the print head is installed in the receptor, the first movement of the handle locks the latch in the lockable position and the second movement of the handle releases the platform so that the bias means presses the platform in said first direction to engage said electrical connectors and urge the print head into secure engagement with the receptor.