The Hook and Eye: A Spring Tongue That Keeps the Eye In

De Long describes "a hook or fastening for a garment, composed of front and rear portions or the hook proper and the shank formed of substantially parallel sides or bars, and a tongue having its free end forming a loop coincident with the bend of the hook". Fig. 1 is a hook for "a hook and eye"; Fig. 2 shows the same hook on the frame of a suspender buckle or slide. The spring-tongue B "is bowed or swelled outwardly so as to approach the front portion." An eye drawn between the front and rear of the hook "bears against the tongue and rides over the same, forcing it backward", reaches the bend D, and the tongue returns, "serving to retain the eye". The eye then sits in both the bend D and the loop C; the loop strengthens the hook and stops the eye "from slipping behind the tongue". Both tongue and loop lie between the side pieces, so they are "laterally restrained" when the hook is under strain.

With round-nose and flat-nose pliers, bend two plain hooks and two eyes from steel wire about 0.6 mm thick. For two more hooks, bend the wire back on itself so the hook has two parallel side bars, and form a tongue from finer wire (about 0.3–0.4 mm) that runs inside the hook, bowed towards the front, with its end curled into the bend. Sew one of each onto two scraps of cotton fabric, with eyes on the facing edges. Hook them up, then shake and flex the fabric with no tension on it for a minute. Count how often each pair comes apart. Check the tongues under a hand lens afterwards: a tongue that no longer touches the front of the hook has taken a set — make it longer or thinner, as the notebook says.

**Frank E. De Long** of Philadelphia filed US 411,857 on 18 March 1889; it is dated 1 October 1889, with one-half assigned to Charles F. De Long. The claim is the hook of parallel bars with a tongue whose free end forms a loop in the bend, both lying between the side bars. **Honest limits.** The wire modulus and working stress in the notebook are assumed values; the patent gives no dimensions.