A second sounds a long time for the latch to operate. Stuff like that I've encountered has been more like a tenth of a second.
Assuming its a DC system, perhaps you could arrange your own simple delay circuit with a basic relay, a capacitor, and maybe a resistor.
(Sorry I don't know how to put diagrams on here, but -)
Break the line to the pneumatic solenoid and take it through the relay N/O contact. Connect a capacitor across the relay coil. Supply the relay coil/capacitor via a resistor. A bit of bench experiment would be the easiest way to determine resistor capacitor values.
