Patent ID: 7424932

Claim:
A hoisting device for hoisting a load to the roof of a building, said hoisting device comprising: a. a ladder having parallel rails and spaced apart rungs, said ladder having an upper end and a lower end; b. a carriage having a frame and a plurality of axles connected to said frame, and a plurality of wheels connected to said axles, whereby said carriage is supported on said ladder rails by said axles and rollably movable along said ladder rails from said lower end of said ladder to said upper end of said ladder on said axles, and whereby said carriage is supported on said wheels and rollably movable along said roof on said wheels; c. means for supporting said upper end of said ladder on said building; d. means for supporting a load on said carriage; e. means for moving said carriage on said axles along said ladder rails to and from said lower and said upper end of said ladder and to and from said ladder to said roof of said building; f. a first brake connected to said carriage, said first brake having means for engaging said rungs of said ladder, whereby movement of said carriage to said lower end of said ladder will be impeded by said means for engaging said rungs of said ladder; and g. a second brake connected to said carriage, said second brake having means for automatically engaging said roof of said building, whereby movement of said carriage from said roof of said building will be automatically impeded by said means for automatically engaging said roof, wherein said second brake further comprises at least one elongated spike pivotally mounted to said carriage; at least one upper first brake support pin connected to said second brake, whereby said upper brake support pin impedes pivotal rotation of said second brake by contacting said first brake when said second is automatically engaged; at least one brake engagement lever connected to said second brake, whereby said first brake and said second brake are disengaged by movement of said brake engagement lever; and at least one lower first brake support pin connected to said second brake, whereby said lower brake support pin impedes pivotal rotation of said first brake when said first brake and said second brake are disengaged by movement of said brake engagement lever.