The Hollow Glove Stretcher: Tube Jaws and a Puff of Powder

"Heretofore glove-stretchers have been made solid, of hard wood, bone, &c., and to be strong enough it was necessary that the parts should be made thick and heavy." "I prefer to construct the two halves of sheet-steel precisely alike, stamped or pressed into the required tubular or hollow form; but they may be made of sheet-iron, cast metal, hard rubber, or any other material suitable for the purpose."

**Jaws.** Cut two 25 cm lengths of 10 mm aluminium tube. Flatten 3 cm in the middle of each in the vice and drill a 5 mm hole through each flat. Bend the front 10 cm of each gently outward so that, bolted at the flats, the two close to a smooth rounded point. Round the tips with the file and seal them with a dab of epoxy. **Hinge and spring.** Bolt the flats together with an M5 bolt and nut. Seat a compression spring between the handles so it keeps them apart and the jaws closed. **Puffer.** Push clear vinyl tubing onto the rubber bulb, run it along one handle with tape so its end sits between the jaws behind the tips, and fill the bulb with talcum powder. **Test.** Cut 20 cm of the tube and 20 cm of 6 mm aluminium rod and weigh them on the kitchen scale. Clamp each in the vice with 15 cm free, hang the spring scale on the end, pull to 10 N and measure the droop with the ruler. Compare with the notebook. Then slide the closed jaws into a glove finger, squeeze the handles and give the bulb one puff.

**David S. Hayward** of New York filed US 165,096 on 11 June 1875; it is dated 29 June 1875. He showed the powder box as metal or hard rubber, or as a bulb of elastic rubber, and a hinge and spring made of one piece of spring wire. He noted that curved solid handles cut obliquely across the grain were weak. **Honest limits.** Aluminium tube stands in for his stamped sheet steel, and a vinyl tube with an open end for his perforated nozzle. The notebook compares round sections of equal area; its diameters are examples. Your droop readings are the result.