Patent ID: 8757593
Filing Date: 2014-06-24
Classification: E04G

Abstract:
1. A method for lowering a carriage configured to ascend and descend along a support having a series of lugs disposed upon said support, each lug having a top edge and a bottom edge, the carriage comprising a frame comprising a first ratchet pawl configured to engage said top edges of said series of lugs, a sub-carriage slidably disposed within said frame comprising a second ratchet pawl configured to engage said top edges of said series of lugs, and a plunger configured to apply a downward force upon said sub-carriage, the method comprising the steps of: engaging said first ratchet pawl with a first lug; supporting a weight of said carriage with said first ratchet pawl; retracting said second ratchet pawl from said support; applying a downward force upon said sub-carriage, causing said sub-carriage to descend with respect to said frame; engaging said second ratchet pawl upon a second lug; transferring said weight of said carriage to said second ratchet pawl; disengaging said first ratchet pawl from said first lug; retracting said first ratchet pawl away from said support; relaxing said downward force upon said sub-carriage, thereby lowering said frame; and engaging said first ratchet pawl with a third lug, wherein said third lug is disposed below said first lug.