Locating structure for a bounce device in a pen

A locating structure for a bounce device in a pen, comprising:

• a hollow penholder with two ends, a first end thereof having an opening, being provided with a transverse guide groove, and a locating hole being provided below the guide groove and having a size greater than the guide groove;
• a locating device, further comprising a slide block with a lateral receiving hole, a pushbutton with a first spring located in the receiving hole, the slide block being inserted into the penholder through the opening, said pushbutton having a stepped shape at an end thereof, providing a slide tenon and a stop ring corresponding to the guide groove and the locating hole respectively, and providing a stop flange having a size greater than the locating hole;
• a center stick with a first end thereof connecting with the slide block and a second end thereof being a writing part surrounded by a second spring;
• whereby when the pushbutton is pushed to move the slide tenon downward along the guide groove, the first spring is in a state of stretching and urges the stop ring to fit with the locating hole such that the slide block is located to have the writing part extending outwardly from the penholder;
• when the slide tenon is pressed and the pushbutton moves inward in the receiving hole to have the stop ring moving away the locating hole, the second spring is in a state of stretching to restore the slide block to an original position thereof such that the writing part retreats in the penholder.