# US 4,394,031 A · Easily mountable swingable-arm draw-pin retainer

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- Number: US 4,394,031 A
- Document ID: US4394031A
- Status: Granted
- Kind: A
- Application number: 06/153,157
- Filed: 1980-05-27
- Granted: 1983-07-19
- Earliest claimed: 1980-05-27
- Inventors: Roy C. Barton; Dale A. Smith
- Web page: https://patentgrep.com/patent/US4394031A

## CPC

- B60D 1/025: {comprising release or locking lever pins}
- B60D 1/02: Bolt or shackle-type couplings
- F16B 2200/69: Redundant disconnection blocking means
- B60D: VEHICLE CONNECTIONS
- F16B: DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING (couplings for transmitting rotation F16D)

## Abstract

To prevent personal injury and property damage by accidental displacement of a hitch tow-pin, an easily mountable unit has an arm horizontally swingable to and from a position above the upper end of the conventional tow-pin of a clevis-type hitch. The pivot pin for the swingable arm can also serve as part of the unit's mounting structure by extending through a bore in, and anchored to, a draw bar. Or the pivot pin can be fixed to a sleeve slidable over a draw bar. Each species employs a detent device to prevent accidental arm movement away from its draw-pin-retaining position.

## Claims

### Claim 1

In a tow-hitch having a bar attachable to a first vehicle, a therewith-mating clevis attachable to a second vehicle, and a conventional hitch tow-pin couplingly insertable downwardly through alined bores in said bar and said clevis, the improvement comprising: a tow-pin-retaining fully assembled unit having a vertically disposable pivot pin, means for fixing said pivot pin to tow-hitch structure so as to be closely adjacent the axis of said tow-pin in its hitch-coupling arrangement, an arm mounted on said pivot pin for horizontal swinging to and from a position closely above the top of said tow-pin, and detent means for yieldably holding said arm in its tow-pin-overlying and -retaining position, said tow-pin-retaining unit comprising a short sleeve telescopically slidable over a conventional draw-bar, said pivot pin being firmly fastened to the top of said sleeve, said means for fixing being set screws for releasably anchoring said sleeve to said draw-bar, and said detent means comprising a nut fixed to said pivot pin and radially grooved on its arm-facing surface, rounded protuberances on said arm for engaging in the grooves of said nut, and a coil spring around said pivot pin biasing said arm toward said nut.