# US 8,770,374 B2 · Braking system for escalators and moving walkways > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,770,374 B2 - Document ID: US8770374B2 - Status: Granted - Kind: B2 - Application number: 13/712,573 - Filed: 2012-12-12 - Published: 2013-06-20 - Granted: 2014-07-08 - Earliest claimed: 2011-12-14 - Assignees: Thyssenkrupp Elevator Innovation Center, S.A. - Applicants: Thyssenkrupp Elevator Innovation Center, S.A. - Inventors: Miguel Angel Gonzalez Alemany; Alberto Florez Castro; Jose Ojeda Arenas; Eva Rodriguez Rodriguez; Eduardo Moran Garcia; Jose Mendiolagoitia Juliana - Web page: https://patentgrep.com/patent/US8770374B2 ## CPC - B65G 43/00: Control devices, e.g. for safety, warning or fault-correcting - B65G 23/26: Applications of clutches or brakes - B66B 25/00: Control of escalators or moving walkways (walkways of variable speed type B66B21/12; handrails of variable speed type B66B23/26; of general application G05) - B66B 29/00: Safety devices of escalators or moving walkways (walkways of variable speed type B66B21/12; handrails of variable speed type B66B23/26) - B65G: TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS (packaging B65B; handling thin or filamentary materials, e.g. paper sheets or thread, B65H; cranes B66C; portable mobile or lifting or hauling appliances, e.g. hoists, B66D; devices for lifting or lowering goods for loading or unloading purposes, e.g. fork-lift trucks, B66F9/00; emptying bottles, jars, casks, barrels or similar containers, not otherwise provided for, B67C9/00; delivering or transferring liquids B67D; filling or discharging vessels for liquefied, solidified or compressed gases F17C; pipe-line systems for fluids F17D) - B66B: ELEVATORS; ESCALATORS OR MOVING WALKWAYS ({apparatus for raising or lowering persons on theatrical stages or the like A63J5/12} ; funicular railbound systems with rigid ground-supported tracks and cable traction, e.g. cliff railways, B61B9/00; arrangements of ammunition handlers in vessels B63G3/00; hoists, lifts, or conveyors for loading or unloading in general B65G; braking or detent devices controlling normal movements of winding drums or barrels B66D; ship-lifting devices E02C; garages for many vehicles with mechanical means for lifting vehicles E04H6/12; hoists for feeding ammunition or projectiles to launching apparatus or to loading mechanisms F41A9/00) ## Abstract A braking system for escalators and moving walkways, includes a braking device (3) with a main brake (30) of the type which is released when there is no voltage in its electric activator, and an auxiliary brake (31) of the type which is closed when there is no voltage in its electric activator. A controller (1) controls the braking device (3), prepared for obtaining the load of the escalator or moving walkway, and calculates the braking torque required for each braking device (3) depending on the load and activating the braking device (3) for obtaining the corresponding torque while braking when a braking command is received. The auxiliary brake is activated (32) for taking the escalators or moving walkway to a safe position when there is a system failure. ## Claims ### Claim 1 A braking system for escalators and moving walkways, comprising: at least one braking device, each braking device having a main brake which is released when there is no voltage in an electric activator, and an auxiliary brake which is closed when there is no voltage in the electric activator; a controller for controlling the at least one braking device, configured for: obtaining a load of the escalator or moving walkway, calculating braking torque required for each braking device depending on said load and activating the at least one braking device for obtaining corresponding torque while braking when a braking command is received; activating the at least one auxiliary brake for taking the escalator or moving walkway to a safe position when system failure occurs. ### Claim 2 (depends on 1) The system according to claim 1, wherein for applying the braking torque the controller is configured for calculating the braking current which has to be supplied to electric activator of the main brake and applying said current while braking. ### Claim 3 (depends on 2) The system according to claim 2, wherein the controller comprises a power controller configured for keeping the braking current constant. ### Claim 4 (depends on 1) The system according to claim 1, wherein the controller is configured for activating either the main brake alone or the main brake together with the auxillary brake, depending on the value of the calculated braking torque. ### Claim 5 (depends on 1) The system according to claim 1, wherein the controller is configured for: obtaining actual deceleration of the escalator or moving walkway caused by activating the braking device; comparing the actual deceleration with theoretical deceleration obtained according to the calculated braking torque, such that if the difference between the actual deceleration and the theoretical deceleration exceeds a pre-established limit, the controller considers the existence of a system failure. ### Claim 6 (depends on 1) The system according to claim 1, wherein the electric activator of the main brake and of the auxiliary brake comprise at least one solenoid. ### Claim 7 (depends on 1) The system according to claim 1, wherein the controller is configured for obtaining the load of the escalator or moving walkway according to at least any one of the following: based on data from sensors connected to the controller; from information supplied by an input signal; through information supplied by a load estimator responsible for estimating the load; through estimating torque from torque-voltage or torque-current transducers coupled to output shafts of a geared motor assembly of the escalator or moving walkway; through a power estimator from calculating a speed by an encoder and current and voltage supplied to the motor or motors at each instant in time. ### Claim 8 (depends on 1) The system according to claim 1, further comprising a load estimator responsible for estimating the load of the escalator or moving walkway. ### Claim 9 (depends on 1) The system according to claim 1, where the escalator or moving walkway has a plurality of electric geared motors, wherein the controller comprises one control devices for each braking device coupled to each geared motor, the different control devices being interconnected to one another for distributing the braking torques such that safe braking with no overstraining on the mechanical components is assured. ### Claim 10 (depends on 1) The system according to claim 1, comprising an uninterrupted power supply system for assuring correct operation of the system even in the event of a power grid failure. ### Claim 11 (depends on 1) The system according to claim 1, wherein the controller has a learning algorithm to compensate for loss of brake effectiveness with use such that the braking distance always remains constant, for which purpose the controller is configured for: analyzing distance values obtained in each braking; if the braking distance is greater than an assigned distance, increasing the next braking by a braking force value in a manner that is proportional to effectiveness lost in preceding brakings. ### Claim 12 (depends on 1) The system according to claim 1, wherein the controller is based on a redundant CPU scheme which is safe in the event of failures of an internal element of the controller.