Patents by Inventor William D. Piper

William D. Piper has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Shoulder cushion attachment for ladders
    Patent number: 5058789
    Abstract: A ladder attachment which cushions the shoulder of a person carrying the ladder. A foam cushion is bonded to a base which slips onto either side rail of the ladder. The base is shaped to mate with the channel shape of the ladder rail and has inturned lips on the edges of its sides which hook over the flange edges of the rail. A resilient foam pad is interposed between the base plate of the base and the channel web to apply a force which assures that the lips remain hooked on the flange edges.
    Type: Grant
    Filed: July 24, 1990
    Date of Patent: October 22, 1991
    Inventor: William D. Piper