Shaft coupler

A device for rapidly attaching and releasing the shafts of a horse-drawn vehicle, to and from the harness of the horse, primarily in connection with harness horse racing, comprising a spring loaded device having an elongated rectangular main frame;

• the upper part of said frame consisting of a buckle arrangement by means of which the said device is attached to a backband of the harness;
• the lower part of the device being provided with a loop for attachment of a harness connecting strap;
• a small rectangular plate just below the buckle arrangement and extending from the main frame and at right angles to it, having a hole in it for the passage therethrough of a latch pin;
• a clevis formed by two spaced, small, parallel plates extending at right angles from the main frame, and located just above the said bottom loop, for inserting the free end of a sulky shaft therein, with the free end not extending beyond the clevis and being reduced in size relative to the remainder of the shaft;
• a hole in each of the clevis plates for the passage therethrough of said latch pin;
• said latch pin comprising a metal spring-loaded rod which passes through said latch pin holes in the top extension plate and the clevis plates;
• a spring surrounding the latch pin, in compression, between the upper extension plate and a washer which is permanently attached to the latch pin, said pin being long enough to extend above the upper plate extension, and below said clevis in its locked position;
• and a rope or cable attached to the upper end of said pin by means of which the pin can be pulled upwardly to release the shaft held in said clevis;
• said shaft having a hole in its free end for the passage of said latch pin therethrough.