Patent attributes
A wheel chock includes a convex load surface configured to be engaged by a vehicle tire. The resultant force exerted by the vehicle tire on the wheel chock can be expressed as a vector normal to the convex surface, at a contact angle θ. As dynamic loading forces push the vehicle into the wheel chock, the tire rides up the convex surface of the chock, thereby increasing the contact angle θ. For contact angles greater than 45°, the vertical component of the resultant force will increase, and the horizontal component will decrease. The net effect is that, under dynamic loading, the chock will tend to anchor itself downwards rather than slide backwards or tip over. Also disclosed is a chock extractor secured to the wheel chock. Rotating the extractor handle in turn rotates an extractor foot, which pivots and lifts the wheel chock off the ground to disengage the chock.