Control device assembly

This invention relates to the assembly of a wall mounted programmable device such as a thermostat. In particular, this invention relates to the assembly of a keyboard, a display and a printed circuit board within such a wall mounted programmable device. The mounting of keyboard and display elements relative to a printed circuit board within a programmable thermostat is extremely important since these are the elements which receive information, process information, and display information to the user of the thermostat. Various approaches have heretofore been taken to mounting these elements so that they are precisely registered relative to each other in the thermostat. A wall mounted control device such as a thermostat includes a front panel housing having a plurality of locating elements formed therein which allow the mounting of a display, a keyboard unit and a printed circuit board with respect to each other. The front panel housing includes a latch which engages an edge of the display following placement of the display into position within the front panel housing. The keyboard unit is positioned relative to the latched display. The printed circuit board is snapped into place beneath certain raised elements formed in the periphery of the front panel housing. The front panel housing with the thus assembled display, keyboard unit and printed circuit board therein is aligned and snap fitted to a rear or back housing of the wall mounted device.