Patent ID: 8382046

Claim:
A riser lock unit, comprising: a generally L-shaped base member including a laterally open-sided lower plate defining a pair of generally parallel and laterally extending lower legs, said base member further including a generally upright support plate joined to a rear margin of and oriented generally perpendicular to said lower plate, said upright support plate having an elongated slot formed therein to extend generally in parallel with said rear margin; a laterally open-sided upper plate defining a pair of generally parallel and laterally extending upper legs spaced apart at one end common with said laterally open-sided lower plate, said upper plate defining a rear margin extending through said elongated slot formed in said upright support plate; and a flange coupled to said upper plate rear margin and oriented generally perpendicular to said upper plate; said flange being manually depressible against said upright support plate to orient said upper plate sufficiently in parallel with said lower plate to accommodate slide-fit mounting of said upper legs and said lower legs onto an elevated sprinkler riser projecting upwardly from a sprinkler housing, said flange being thereupon releasible to permit partial retraction of the elevated sprinkler riser whereby inboard edges of said upper legs bind against and mechanically retain the riser in an at least partially elevated position; said flange being manually depressible against said upright support plate for return orientation of said upper plate to a position sufficiently in parallel with said lower plate, whereby the riser is released from said upper legs and thereby permitted to return to a normal position retracted within the sprinkler housing.