# US 10,501,058 B2 · Wheel chock device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,501,058 B2 - Document ID: US10501058B2 - Status: Granted - Kind: B2 - Application number: 15/543,846 - Filed: 2016-01-14 - Published: 2017-12-28 - Granted: 2019-12-10 - Earliest claimed: 2015-01-14 - Applicants: Iguane Technologies Inc. - Inventors: Denis Rancourt; Yves St-Amant; Charles Khazoom - Web page: https://patentgrep.com/patent/US10501058B2 ## CPC - B60T 3/00: Portable devices for preventing unwanted movement of vehicles, e.g. chocks - B60P 3/077: Wheel cradles, chocks, or wells - 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 - B60P: VEHICLES ADAPTED FOR LOAD TRANSPORTATION OR TO TRANSPORT, TO CARRY, OR TO COMPRISE SPECIAL LOADS OR OBJECTS (vehicles with special provisions for transporting patients or disabled persons, or their personal conveyances A61G3/00) ## Abstract A wheel chock (40) has a profile that provides maximum restraining capacity when the wheel (22) is completely supported thereby, by mitigating undesirable failure modes while promoting the safest failure mode of operation, slipping on ground (30). The profile includes a generally flat bottom surface (46) for being in contact with a ground surface (30), a substantially broken top surface (44) for being in contact with the wheel (22), the top surface (44) including a first contact point (P1), a second contact point (P2), and a contact surface (52) there between allowing at most two points of contact at a time between the contact surface (52) and the wheel (22), with the second contact point (P2) being one of the two points of contact. A more specific clothoid profile of the contact surface (52) is preferred to minimize the rate of variation of the contact force of the wheel (22) with the chock (40). ## Claims ### Claim 1 A wheel chock device for stopping a wheel of a vehicle from rolling on a ground surface, said device comprising: a profile including a generally flat bottom surface for being in contact with a ground surface and extending between a first end and a second end; and a top surface for being in contact with the wheel, the top surface extending over the bottom surface, the top surface having a contact surface being able to support the wheel simultaneously over at most two points of contact thereof; the top surface including a first segment adjacent the first end and a second segment extending from the first segment and continuing the first segment away from the first end, the first and second segments defining a contact surface, the first segment being able to support the wheel and forming a generally flat first plane defining a first angle (ϕ1) relative to the bottom surface, a tangent of the first angle (ϕ1) being equal to or smaller than a minimum static coefficient of friction (μmin) between the bottom surface and the ground surface; and the first segment including a first contact point (P1) adjacent the first end and located at a first height (hR) relative to the bottom surface to allow the wheel to engage the chock device, the first height (hR), relative to a radius (r) of the wheel and the minimum static coefficient of friction (μmin), being obtained from the equation: h R < r ( 1 - 1 1 + μ min 2 ) the second segment including a second contact point (P2) being adjacent the second end and closer to the second end than the first contact point (P1) is; the second segment, at the second contact point (P2), defining a tangent having a second angle (ϕ2) relative to the bottom surface, a tangent of the second angle (ϕ2) being equal to or smaller than a maximum static coefficient of friction (μmax) between the bottom surface and the ground surface, and larger than the tangent of the first angle (ϕ1); wherein a perpendicular projection of the first contact point (P1) on the bottom surface intersects the bottom surface at a first intersection (R) adjacent the first end, wherein the tangent of the second angle (ϕ2) intersects the bottom surface at a second intersection (B), and wherein the first segment has a rolling length (AA′), starting at the first point of contact (P1), ensuring the wheel to roll on the first segment and be entirely supported thereon before contacting the second segment; a minimum distance (BRmin) between the first and second intersections, relative to the radius (r) of the wheel, the rolling length (AA′), and both the minimum (μmin) and maximum (μmax) static coefficients of friction, is obtained by the equation: BR min = r ( μ max 1 + μ max 2 - μ min 1 + μ min 2 - 1 μ max + 1 μ max ⁢ 1 + μ max 2 ) + AA ′ ( 1 1 + μ min 2 - μ min μ max ⁢ 1 1 + μ min 2 ) . ### Claim 2 (depends on 1) The wheel chock device according to claim 1, wherein the second contact point (P2) is at a second height (hT) relative to the bottom surface, the second height (hT) being larger than the first height (hR). ### Claim 3 (depends on 2) The wheel chock device according to claim 2, wherein a projection of the radius of the wheel extending through the second contact point (P2), when the wheel is in contact with the second contact point (P2), intersects the bottom surface adjacent the second end. ### Claim 4 (depends on 3) The wheel chock device according to claim 3, wherein the second height (hT), relative to both the radius (r) of the wheel and the maximum static coefficient of friction (μmax), is obtained from the equation: h T = r ( 1 - 1 1 + μ max 2 ) . ### Claim 5 (depends on 3) The wheel chock device according to claim 3, wherein the wheel has a radius varying between a minimum radius (rmin) and a maximum radius (rmax), the second height (hT), relative to both a maximum radius (rmax) of the wheel and the maximum static coefficient of friction (μmax), being obtained from the equation: h T = r max ( 1 - 1 1 + μ max 2 ) . ### Claim 6 (depends on 3) The wheel chock device according to claim 3, wherein the second segment is a slippery surface having a coefficient of friction with the wheel equal to or smaller than 0.5. ### Claim 7 (depends on 6) The wheel chock device according to claim 6, wherein the slippery surface includes a plurality of rollers freely rotatably mounted onto the chock device and being in parallel relationship relative to one another. ### Claim 8 (depends on 2) The wheel chock device according to claim 2, wherein the top surface includes an anterior portion extending from the second contact point (P2) to the second end, the anterior portion always having a tangent having an angle relative to the bottom surface equal to or less than the second angle (ϕ2). ### Claim 9 (depends on 2) The wheel chock device according to claim 2, wherein the contact surface allows either only one point of contact at a time between said contact surface and the wheel or at most two points of contact therebetween with the second contact point (P2) being one of said at most two points of contact. ### Claim 10 (depends on 9) The wheel chock device according to claim 9, wherein the second segment includes a generally concave curved surface having a curvature radius larger than the radius (r) of the wheel. ### Claim 11 (depends on 10) The wheel chock device according to claim 10, wherein the concave curved surface has a clothoid or piece-wise clothoids profile starting with a slope equal to the first angle (ϕ1) adjacent the first segment and ending with a slope substantially equal to or larger than the second angle (ϕ2). ### Claim 12 (depends on 2) The wheel chock device according to claim 2, wherein the bottom surface includes a covering pad mounted thereon for contacting the ground surface. ### Claim 13 (depends on 12) The wheel chock device according to claim 12, wherein the covering pad is interchangeable. ### Claim 14 (depends on 1) The wheel chock device according to claim 1, wherein the second height (hT), relative to the radius (r) of the wheel, both the minimum (μmin) and maximum (μmax) static coefficients of friction, and the rolling length (AA′), is obtained from the equation: h T = r ( 1 - 1 1 + μ max 2 ) + AA ′ ⁢ μ min 1 + μ min 2 . ### Claim 15 (depends on 1) The wheel chock device according to claim 1, wherein the rolling length (AA′) is larger than 30% of a sustentation length of the wheel, the sustentation length corresponding to a length of a deformed outer perimeter of the wheel being simultaneously in contact with a supporting surface. ### Claim 16 (depends on 15) The wheel chock device according to claim 15, wherein the rolling length (AA′) is between 40% and 60% of the sustentation length of the wheel. ### Claim 17 (depends on 15) The wheel chock device according to claim 15, wherein the rolling length (AA′) entirely supports the wheel. ### Claim 18 (depends on 1) The wheel chock device according to claim 1, wherein the wheel has a radius varying between a minimum radius (rmin) and a maximum radius (rmax), the first height (hR), relative to both a minimum radius (rmin) and the minimum static coefficient of friction (μmin), being obtained from the equation: h R < r min ( 1 - 1 1 + μ min 2 ) . ### Claim 19 (depends on 18) The wheel chock device according to claim 18, wherein the minimum distance (BRmin) between the first and second intersections, relative to both the minimum (rmin) and maximum (rmax) radii of the wheel, the rolling length (AA′), and both the minimum (μmin) and maximum (μmax) static coefficients of friction, is obtained by the equation: BR min = r max ( μ max 1 + μ max 2 - μ min 1 + μ min 2 - 1 μ max + 1 μ max ⁢ 1 + μ max 2 ) + AA ′ ( 1 1 + μ min 2 - μ min μ max ⁢ 1 1 + μ min 2 ) + ( r max - r min ) ⁢ ( 1 - 1 / 1 + μ min 2 μ min ) . ### Claim 20 (depends on 19) The wheel chock device according to claim 19, wherein the second predetermined height (hT), relative to the maximum radius (rmax) of the wheel, both the minimum (μmin) and maximum (μmax) static coefficients of friction, and the rolling length (AA′), is obtained from the equation: h T = r max ( 1 - 1 1 + μ max 2 ) + AA ′ ⁢ μ min 1 + μ min 2 .