Cup lid and method of using same

A method of securing a lid to a cup comprising:

• providing a lid having,
• a top,
• a continuous sidewall extending downwardly from the top and terminating to form a rim,
• an annular groove formed in the continuous sidewall,
• a plurality of ridges arranged circumferentially on and protruding radially inwardly from an inner surface of the continuous sidewall, wherein each ridge of the plurality of ridges includes a first end arranged adjacent to the annular groove, a second end arranged adjacent to the rim, and a height that progressively increases as the ridge extends from the second end to the first end,
• arranging the rim around a lip of the cup,
• contacting the second end of each ridge of the plurality of ridges with the lip,
• pressing the lid against the plurality of ridges while rotating the lid, whereby each ridge of the plurality of ridges deforms the lip, and
• sliding the lip along from the second end to the first end of each ridge of the plurality of ridges and thereafter depositing the lip within the annular groove.

A cup lid comprising:

• a top cover,
• a continuous sidewall extending downwardly from the top cover and terminating to form a continuous rim,
• an annular groove formed in the continuous sidewall,
• a continuous sidewall portion extending to and between an edge of the annular groove and the continuous rim, wherein the continuous sidewall portion tapers outwardly from the edge of the annular groove as it extends to the continuous rim, and
• a plurality of ridges arranged circumferentially on and protruding radially inwardly from an inner surface of the continuous sidewall portion, wherein each ridge of the plurality of ridges includes a first end arranged adjacent to the annular groove, a second end arranged adjacent to the continuous rim, and a height that progressively increases as the ridge extends from the second end to the first end,
• wherein no ridge of the plurality of ridges contacts another ridge of the plurality of ridges.