# US 7,909,142 B2 · Braking device for elevating platform assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,909,142 B2 - Document ID: US7909142B2 - Status: Granted - Kind: B2 - Application number: 11/419,229 - Filed: 2006-05-19 - Published: 2008-11-06 - Granted: 2011-03-22 - Earliest claimed: 2006-05-19 - Assignees: Hydro Mobile - Inventors: Gérard Noel - Web page: https://patentgrep.com/patent/US7909142B2 ## CPC - B66F 17/006: {for working platforms} - F16D 59/02: spring-loaded and adapted to be released by mechanical, fluid, or electromagnetic means - B66F: HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD ({invalid lifting devices A61G7/10; } mounting artificial islands on piles or like supports E02B17/00; scaffolding combined with lifting devices E04G1/22; lifting devices for sliding forms E04G11/24; lifting of buildings E04G23/06; shores or struts E04G25/00; lifts or other hoisting devices on ladders E06C7/12; props for mining E21D15/00) - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES ## Abstract A braking device for an elevated platform assembly comprising a platform moveable along a generally vertical mast supporting an upright rack comprises an input gear assembly in mating engagement with the rack, a centrifugal actuator communicating with the input assembly and a spring-loaded brake responsive to the centrifugal actuator. The spring-loaded brake engages the rack and arrests the platform when the platform descends the mast at a rate above an upper threshold limit. ## Claims ### Claim 1 A braking device for an elevating platform assembly, said elevating platform assembly comprising a platform moveable along a generally vertical mast supporting an upright rack, said braking device comprising: an input gear assembly in mating engagement with said rack; a centrifugal actuator communicating with said input gear assembly and comprising a trigger mechanism; and a spring-loaded brake responsive to said centrifugal actuator to engage said rack and arrest said platform when said platform descends said mast at a rate above an upper threshold limit resulting in release of said trigger mechanism, said spring-loaded brake automatically resetting said trigger mechanism as downward movement of said platform is arrested. ### Claim 2 (depends on 1) A braking device according to claim 1 wherein said spring-loaded brake comprises a braking rack to engage the rack on said mast. ### Claim 3 (depends on 2) A braking device according to claim 2 wherein said centrifugal actuator times triggering of said spring-loaded brake so that the teeth of said braking rack cleanly mesh with the teeth on the rack of said mast. ### Claim 4 (depends on 3) A braking device according to claim 3 wherein said centrifugal actuator comprises a drum assembly coupled to said input gear assembly, said trigger mechanism acting between said input gear assembly and said spring-loaded brake, said drum assembly causing said input gear assembly to release said trigger mechanism thereby to deploy said spring-loaded brake when centrifugal forces sensed by said drum assembly signify a rate of descent of said platform above said upper threshold limit. ### Claim 5 (depends on 4) A braking device according to claim 4 wherein said drum assembly comprises a biased assembly rotatable with said input gear assembly, said biased assembly overcoming the bias when centrifugal forces thereon signify a rate of descent of said platform above said upper threshold limit resulting in release of said trigger mechanism. ### Claim 6 (depends on 5) A braking device according to claim 5 where the bias is adjustable. ### Claim 7 (depends on 5) A braking device according to claim 5 wherein said trigger mechanism comprises a lever coupled adjacent one end to said spring-loaded brake, said lever having a keeper adjacent its opposite end that is retained by a latch of said input gear assembly, said latch being released when the rate of descent of said elevating platform is above said upper threshold limit. ### Claim 8 (depends on 7) A braking device according to claim 7 wherein said input gear assembly comprises an input gear in mating engagement with said rack, a shaft coupled to said input gear and said biased assembly and a latch release mechanism responsive to movement of said biased assembly that occurs when said biased assembly overcomes said bias. ### Claim 9 (depends on 8) A braking device according to claim 8 wherein said drum assembly comprises a notched inner surface that is engaged by said biased assembly when said biased assembly overcomes said bias, engagement of said biased assembly and notched inner surface causing rotation of said drum assembly and actuation of said latch release mechanism. ### Claim 10 (depends on 9) A braking device according to claim 9 wherein the spacing of the notches on said inner surface and the spacing of teeth of said input gear are substantially equal. ### Claim 11 (depends on 3) A braking device according to claim 3 wherein said spring-loaded brake comprises a linearly slidable push block acting on said braking rack. ### Claim 12 (depends on 11) A braking device according to claim 11 wherein said push block presents an upwardly and forwardly inclined surface that acts on a complimentary surface of said braking rack. ### Claim 13 (depends on 12) A braking device according to claim 12 wherein said spring-loaded brake further comprises a low friction material acting between the inclined surface of said push block and the complimentary surface of said braking rack. ### Claim 14 (depends on 13) A braking device according to claim 13 wherein said braking rack is slidable along said low friction material. ### Claim 15 (depends on 1) A braking device according to claim 1 wherein the centrifugal actuator is adjustable to alter the upper threshold limit. ### Claim 16 An elevating platform comprising: at least one mast; a vertical rack on said at least one mast; an elongate platform coupled to said at least one mast and moveable therealong; a drive mechanism acting between said platform and said mast to effect movement of said platform along said mast; and an emergency braking device on said platform and engaging said rack, said emergency braking device comprising: an input gear assembly in mating engagement with said rack; a centrifugal actuator communicating with said input gear assembly and comprising a trigger assembly; and a spring-loaded brake responsive to said centrifugal actuator to engage said rack and arrest said platform when said platform descends said mast at a rate above an upper threshold limit resulting in release of said trigger assembly, said spring-loaded brake automatically resetting said trigger mechanism as downward movement of said platform is arrested. ### Claim 17 (depends on 16) An elevating platform according to claim 16 wherein said spring-loaded brake comprises a braking rack to engage the rack on said mast. ### Claim 18 (depends on 17) An elevating platform according to claim 17 wherein said centrifugal actuator times triggering of said spring-loaded brake so that the teeth of said braking rack cleanly mesh with the teeth on the rack of said mast. ### Claim 19 (depends on 18) An elevating platform according to claim 18 wherein said spring-loaded brake comprises a linearly slidable push block acting on said braking rack. ### Claim 20 (depends on 19) An elevating platform according to claim 19 wherein said push block presents an upwardly and forwardly inclined surface that acts on a complimentary surface of said braking rack. ### Claim 21 (depends on 20) An elevating platform according to claim 20 wherein said spring-loaded brake further comprises a low friction material acting between the inclined surface of said push block and the complimentary surface of said braking rack. ### Claim 22 (depends on 21) An elevating platform according to claim 21 wherein said braking rack is slidable along said low friction material. ### Claim 23 (depends on 16) An elevating platform according to claim 16 wherein the centrifugal actuator is adjustable to alter the upper threshold limit. ### Claim 24 A braking device for an elevating platform assembly, said elevating platform assembly comprising a platform moveable along a generally vertical mast supporting an upright rack, said braking device comprising: an input gear assembly in mating engagement with said rack; a centrifugal actuator communicating with said input gear assembly; and a spring-loaded brake responsive to said centrifugal actuator to engage said rack and arrest said platform when said platform descends said mast at a rate above an upper threshold limit, said spring-loaded brake comprising a braking rack to engage the rack on said mast and a linearly slidable push block acting on said braking rack, wherein said push block presents an upwardly and forwardly inclined surface that acts on a complimentary surface of said braking rack. ### Claim 25 (depends on 24) A braking device according to claim 24 wherein said spring-loaded brake further comprises a frame accommodating said braking rack and said push block and at least one spring member acting between said frame and said push block to bias said push block towards said braking rack, said centrifugal actuator overcoming the bias when said platform descends said mast at a rate below said upper threshold limit. ### Claim 26 (depends on 25) A braking device according to claim 25 wherein said centrifugal actuator comprises a drum assembly coupled to said input gear assembly and a trigger mechanism acting between said input gear assembly and said spring-loaded brake, said drum assembly causing said input gear assembly to release said trigger mechanism thereby to deploy said spring-loaded brake when centrifugal forces sensed by said drum assembly signify a rate of descent of said platform above said upper threshold limit. ### Claim 27 (depends on 26) A braking device according to claim 26 wherein said spring-loaded brake further comprises a low friction material acting between the inclined surface of said push block and the complimentary surface of said braking rack. ### Claim 28 (depends on 27) A braking device according to claim 27 wherein said braking rack is slidable along said low friction material. ### Claim 29 (depends on 26) A braking device according to claim 26 wherein said push block and braking rack are configured to automatically reset the trigger mechanism as downward movement of said platform is arrested. ### Claim 30 A braking device for an elevating platform assembly, said elevating platform assembly comprising a platform moveable along a generally vertical mast supporting an upright rack, said braking device comprising: an input gear assembly in mating engagement with said rack; a centrifugal actuator communicating with said input gear assembly and comprising a trigger mechanism; and a spring-loaded brake responsive to said centrifugal actuator to engage said rack and arrest said platform when said platform descends said mast at a rate above an upper threshold limit, said spring-loaded brake automatically resetting said trigger mechanism as downward movement of said platform is arrested, wherein said trigger mechanism comprises a lever coupled adjacent one end to said spring-loaded brake, said lever having a keeper adjacent its opposite end that is retained by a latch of said input gear assembly, said latch being released when the rate of descent of said elevating platform is above said upper threshold limit thereby to cause said trigger mechanism to release said spring-loaded brake.