# US 2012/0240707 A1 · Safety system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2012/0240707 A1 - Document ID: US20120240707A1 - Status: Published application - Kind: A1 - Application number: 13/453,526 - Filed: 2012-04-23 - Published: 2012-09-27 - Earliest claimed: 2003-10-29 - Inventors: Yavor PACHOV - Web page: https://patentgrep.com/patent/US20120240707A1 ## CPC - B66D 1/14: Power transmissions between power sources and drums or barrels {(including brakes, one-way brakes, one-way clutches, clutches activated alternately with brakes, fixed ratio gearing unless otherwise provided for in B66D1/16 - B66D1/24)} - B60T 11/04: transmitting mechanically - B66D 1/54: Safety gear - B66D 5/026: {Fluid-resistance brakes} - B66D 5/22: with axial effect - B66D 5/30: electrical - F16D 63/00: Brakes not otherwise provided for; Brakes combining more than one of the types of groups F16D49/00 - F16D61/00 - F16H 1/16: comprising worm and worm-wheel - F16H 35/10: Arrangements or devices for absorbing overload or preventing damage by overload - F16D 2121/24: using motors - F16D 2125/52: with non-parallel stationary axes, e.g. worm or bevel gears - F16D 2127/06: Locking mechanisms, e.g. acting on actuators, on release mechanisms or on force transmission mechanisms - Y10T 74/19828: Worm - Y10T 74/19847: torque actuated safety devices - B66D: CAPSTANS; WINCHES; TACKLES, e.g. PULLEY BLOCKS; HOISTS (winding or unwinding ropes or cables for feeding or storage purposes B65H; rope or cable winding or unwinding mechanisms for lifts B66B) - B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - F16H: GEARING - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract This safety system includes: a toothed wheel, connected rotationally with respect to at least one rotating member to be braked, a worm driven rotationally by a motor upon rotation of the rotating member and permanently in mesh with the toothed wheel, a housing forming: a longitudinal wall located on the side of the worm diametrically opposed to the toothed wheel, and extending along the worm at a distance of the latter ranging between 0.001 and 0.01 times the diameter of the worm, and a first end wall integral with the longitudinal wall, located opposite a first longitudinal end of the worm; and energy absorption/dissipation elements interposed between the first end wall and the first longitudinal end of the worm, the worm being slidingly mounted in the housing such that the first longitudinal end of the worm comes closer to the first end wall when the worm slides in the housing. ## Claims ### Claim 1 Safety system, intended to be fitted to a mechanism, with one or more rotating members, comprising: a toothed wheel, connected rotationally with respect to at least one rotating member to be braked, a worm having a diameter, driven rotationally by a motor upon the rotation of the rotating member and permanently in mesh with the toothed wheel, a housing forming a longitudinal wall located on the side of the worm diametrically opposed to the toothed wheel, said longitudinal wall extending along the worm at a distance of the latter comprised between 0.001 and 0.01 times the diameter of the worm, and a first end wall integral with said longitudinal wall, located opposite a first longitudinal end of the worm; and first energy absorption/dissipation means interposed between said first end wall and said first longitudinal end of the worm, said worm being slidingly mounted in said housing such that said first longitudinal end of the worm comes closer to said first end wall when said worm slides in said housing. ### Claim 2 (depends on 1) Safety system according to claim 1, characterized in that said housing comprises: a central portion having a wall forming a chamber for containing said toothed wheel; two coaxial tubular extensions, integral with said central portion, forming a longitudinal bore for receiving said worm, at least one lateral wall extending from one extension to the other extension, said longitudinal wall being integrally formed with said coaxial extensions and said at least one lateral wall, and said first end wall being formed by a nut screwed in a tapped bore formed by the corresponding extension. ### Claim 3 (depends on 2) Safety system according to claim 2, characterized in that said chamber of said central portion is formed by a bore having a diameter equal to a 0.001 to 0.01 times the diameter of said toothed wheel. ### Claim 4 (depends on 2) Safety system according to claim 2, characterized in that said housing comprises an intermediate wall integral therewith and extending from one of said extensions to the other extension, said intermediate wall comprising an opening through which said toothed wheel meshes with said worm, the edge delineating said opening surrounding the area in which said toothed wheel meshes with said worm, at a distance comprised between 0.1 to 0.5 times the diameter of said toothed wheel. ### Claim 5 (depends on 1) Safety system according to claim 1, characterized in that the worm comprises at least one cylindrical portion coaxial with its threaded portion, having said diameter, and the said bore has a diameter equal to the diameter of the worm plus 0.001 to 0.01 times the diameter of the worm, such that said wall delineating said bore is at the immediate vicinity of this or these cylindrical portions. ### Claim 6 (depends on 1) Safety system according to claim 1, characterized in that the peripheral outer edges of the threads of the worm are flat viewed in a plane parallel to the axis of the worm. ### Claim 7 (depends on 1) Safety system according to claim 1, characterized in that said housing forms a second end wall integral with said longitudinal wall, located opposite the second longitudinal end of the worm, and the system comprises second energy absorption/dissipation means interposed between said second end wall and said second longitudinal end of the worm. ### Claim 8 (depends on 1) Safety system according to claim 1, characterized in that said energy absorption/dissipation means comprise at least one resilient means, such as an elastomer spring, interposed between said first or second longitudinal end of the worm and said first or second end wall. ### Claim 9 (depends on 8) Safety system according to claim 8, characterized in that said energy absorption/dissipation means comprise at least one elastomer spring which is made in a material that is permanently deformed when it undergoes forces beyond a predetermined threshold, and which, when deformed, prevents the worm to return to its normal position and thus making impossible the normal use of the safety system. ### Claim 10 (depends on 1) Safety system according to claim 1, characterized in that said energy absorption/dissipation means comprise: a liquid contained in the space delimited by at least one piston, against which one of said first or second longitudinal end of the worm comes to bear, and one or more ducts and/or interstices for said liquid to escape upon the sliding of the worm, said one or more ducts and/or interstices having restricted flow sections, suitable for allowing the said liquid to escape only over a non-instantaneous time interval. ### Claim 11 (depends on 10) Safety system according to claim 10, characterized in that the said one or more ducts and/or interstices comprise means for adjusting the flow of liquid. ### Claim 12 (depends on 10) Safety system according to claim 10, characterized in that the said one or more ducts and/or interstices comprise means for preventing the return of the liquid, which make it possible to obtain a different damping for each sliding direction of the worm. ### Claim 13 (depends on 11) Safety system according to claim 11, characterized in that the means for adjusting the flow rate of the liquid comprise a ring secured to the worm, a tubular member, engaged adjustably through this ring and a rod engaged adjustably in the tubular member, the tubular member and the rod having radial holes communicating with each other, the rod having grooves extending in the circumferential direction and of variable depth, and being adapted to be disposed in a predetermined angular position relative to the tubular member. ### Claim 14 (depends on 1) Safety system according to claim 1, characterized in that it includes sensors or detectors (101) of the sliding of the worm, which actuate command or control means which act on the means for driving the said one or more rotating members. ### Claim 15 (depends on 1) Safety system according to claim 1, characterized in that said energy absorption/dissipation means comprise friction connecting means between the toothed wheel and its hub or between the toothed wheel and the shaft receiving the wheel (6), freeing the pivoting of the wheel (6) with respect to the hub beyond a certain torque threshold, with friction. ### Claim 16 (depends on 1) Safety system according to claim 1, characterized in that it comprises an electronic controller for controlling the maximum speed of the motor for actuating the worm. ### Claim 17 (depends on 16) Safety system according to claim 16, characterized in that the supply to the motor and the control of the speed thereof are performed separately from those of the motor of the mechanism, by means of an electronic controller and a controller having an independent link to the control station of the mechanism, said control station delivering redundant information to the said controller. ### Claim 18 (depends on 1) Safety system according to claim 1, characterized in that the pitch of the thread of the worm is greater than the width of each tooth of the toothed wheel, so that a play exists between the thread and the teeth of the toothed wheel, the play being such that the worm can rotate on 2 to 20° with respect to the toothed wheel when the toothed wheel is fixed in rotation. ### Claim 19 (depends on 1) Safety system according to claim 1, characterized in that said first energy absorption/dissipation means are so located with respect to the worm that a play exists between said first energy absorption/dissipation means and said first longitudinal end of the worm, the play being comprised between 0.005 and 0.05 times the diameter of said worm. ### Claim 20 (depends on 7) Safety system according to claim 7, characterized in that said first and second energy absorption/dissipation means are so located with respect to the worm that a play exists between said first and second energy absorption/dissipation means and said respective first and second longitudinal end of the worm, the play being comprised between 0.005 and 0.05 times the diameter of said worm.