Patents by Inventor Robert M. Crist

Robert M. Crist 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).

  • Patent number: 4524905
    Abstract: A signal device for attachment to standard, front-opening, outside mail boxes. The device comprises a clip member, a coil spring attached at one end to the clip, and a small flag or other visual indicating means mounted on the opposite end of the spring. The device is installed by inserting the clip over an upper edge of the open end of the mail box, without screws, rivets, or other permanent attachment means and without modifying or piercing the mail box in any way. The coil spring has a normal, unflexed position extending essentially vertically upward from the front, upper edge of the mail box and the device is "set" by flexing the spring downwardly from the end with the box door open to place the flag inside the box. The door is then closed to hold the spring in the flexed position. Upon opening the door, e.g., to insert mail, the spring returns to its upright position and the flag may be observed from a remote location, thereby automatically indicating that the box has been opened.
    Type: Grant
    Filed: March 12, 1984
    Date of Patent: June 25, 1985
    Inventor: Robert M. Crist
  • Patent number: 4266452
    Abstract: A special purpose tool for applying torque to a cannister-type oil filter to engage and disengage the threaded end thereof with an engine block. The tool is generally cup-shaped, having an internal surface for engaging the polygonal end of the filter in the manner of a socket wrench. The open end of the tool is flared to a larger diameter than the filter body for catching oil which escapes as the filter is removed, and an internal space is provided to act as a reservoir for the escaping oil. Slots are provided in the lower surface of the tool for receiving a bar to increase the applied torque.
    Type: Grant
    Filed: January 14, 1980
    Date of Patent: May 12, 1981
    Inventor: Robert M. Crist