Abstract: A safety shackle having a modified U-shaped design comprising first and second arms, first and second cusps, a first slot disposed between the first arm and the first cusp and a second slot disposed between the second arm and the second slot, and a working area disposed between the first and second cusps. A designated chain link is introduced with within one of the slots and is locked within the slot by orienting the contiguous chain links in a plane perpendicular to the designated chain link, thereby locking the chain link within the slot.

Abstract: A three-piece safety lock for locking any size trailer safety chain to any size vehicle receiver hitch comprising a primary catch, a locking catch and a keeper element. The safety lock includes a positive self-locking mechanism, termed a keeper element, which ensures that any safety connection or attachment will not become detached from the safety lock, particularly while a vehicle is in transit. The keeper element is pivotably secured to and locks a primary catch and a locking catch. Both the primary catch and the locking catch are configured with corresponding catch openings for receiving the length of a chain or similar article. The primary catch also is provided with a cavity for receiving and locking a link of chain.

Abstract: A self locking chain device for locking a chain to a vehicle comprises an elongated cross bar having an upwardly extending arm attached to each end thereof. Each arm comprises first and second arbors which define a receiving slot for receiving a first interior link of a chain and configured in such a manner to enable two adjacent contiguous links to lock the interior link therein. Both first and second arbors are provided with cusps or projections for limiting passage of the chain link to and from the receiving slot. The first arbor also is provided with a concavity. A second contiguous or selected link, serving as a locking link, is slid over and down the first arbor and to the concavity, thereby double locking the first interior link since the opening between the cusps or projections is less than the combined diameter of the interior link and locking link.