A Cork Puller
The stopper of any ordinary bottle can be easily removed with a puller such as shown in the sketch. The puller is inserted between the stopper and the neck of the bottle until the hook end will pass under the bottom of the stopper, then given a quarter turn and pulled upward.
The construction of the puller vents the cork as it enters and thus no vacuum is created. The cork is pulled more easily than with an ordinary corkscrew, and there is no danger of tearing the cork to pieces.