Abstract: A method of grinding spring ends of helical compression springs is carried out using a numerically controlled spring end grinding machine having a grinding unit, a loading unit and a control unit that controls the loading unit and the grinding unit. The grinding unit has a pair of grinding wheels including two rotatable grinding wheels between which is formed a grinding space. The loading unit has at least one loading plate substantially rotatable axially parallel to the grinding wheels and has a plurality of out-of-axis spring receptacles, each to receive a helical compression spring.

Abstract: A method of grinding spring ends of helical compression springs is carried out using a numerically controlled spring end grinding machine having a grinding unit, a loading unit and a control unit that controls the loading unit and the grinding unit. The grinding unit has a pair of grinding wheels including two rotatable grinding wheels between which is formed a grinding space. The loading unit has at least one loading plate substantially rotatable axially parallel to the grinding wheels and has a plurality of out-of-axis spring receptacles, each to receive a helical compression spring.

Abstract: An essentially waterproof enclosure comprising a waterproof bag and a speaker mounted on the wall of the bag. The bag has an opening of sufficient size to permit an electronic sound producing device to be passed through the opening into the interior of the bag. The sound producing device, which may be a radio receiver, can be coupled to the speaker to drive the speaker. The opening can be closed to provide an essentially waterproof environment for the sound producing device.

Abstract: An "air bumper" which is adapted for attachment to a vehicle to serve as a bumper. The air bumper has a chamber which stores a supply of compressed air that may be used to inflate tires.