United States Patent Office

Thomas Jackson, of Reading Borough, Pennsylvania

Mode of Constructing Swingletree Safety-Hooks to be Used in the Towing of Boats on Canals

Specification of Letters Patent No. 1,196, dated June 25, 1839

To all whom it may concern:

Be it known that I, Thomas Jackson, of the borough of Reading, in the county of Berks and State of Pennsylvania, have invented n new Mode of Constructing Safety- Hooks to be attached to Swingletrees for Holding and Disengaging the Tow-Lines Used in Towing Boats Upon Canals; and I do hereby declare that the following is a full and exact description thereof.

In the accompanying drawing, Figure 1 represents the swingletree safety hook in the proper position for holding the towing line. Fig. 2 shows the hook as disengaged from the trigger, one of the cheeks between which the part B’, of the hook is received being removed for the purpose of exhibiting the trigger and its appendages the more perfectly.

A, A, is the bow, or ring, by which the hook is to be attached to the swingletree.

B, B, is the hook for holding the towing line, and which turns on a joint pin at C. The back part B’, of the hook piece, when the hook is in place, falls in between two cheeks, D, D, where it is held firmly by the trigger E. This trigger works on a joint pin at F, passing through it, and through two cheek pieces G, which rise from, and are in one piece with, the cheek pieces D, D. The trigger is forced forward, and kept in place, by the spring H, which causes the offset I, to catch upon the angle J, of the hook B, B, and to retain it until it is relieved by the forcing back of the trigger E.

A wing, or projecting rim, a, a, a, is formed along the interior edge of the hook piece B, B, which serves the double purpose of widening it out to make a bearing for the rope, and for itself when it is in place between the cheeks D.D.

In this improved safety hoo the towing line may be cast off and replaced without the necessity of making use of the trigger, which is not the case with those formerly used. The trigger also must be disengaged by pressing on it below, instead of above, while in the old hook it was acted upon the upper side, and was not infrequently disengaged accidentally by a blow from the tail of the horse, a thing which cannot possibly occur under the present arrangement.

Having thus fully described the nature of my swingletree safety hook, and the manner in which I construct the same, for the purpose of attaching and detaching the towing lines of canal boats, I hereby declare that what I claim as new therein is –

The manner in which I have combined and connected the respective parts thereof, as described; that is to say, I claim the combination of the hook B, B, with the trigger E, having its tail part, or that which is to be pressed upon in opening A, on the under side of the hook; which latter is so formed as to admit of the removal and replacing of the towing line, when desired without its being necessary to employ the trigger, as herein set forth.

Thomas Jackson

Witnesses:

James M. Lewis,

Charles Lewis.