collapsing device for the third wheel of a golf cart

A collapsing device for the third a wheel of a golf cart comprising:

• a fixing base secured to a bottom end of a lower tube of a golf cart, said fixing base formed with a U-shaped body having an opening, said body having two side walls each provided with an insert groove in an upper end and a lower end, with insert grooves of said two side walls aligned to each other:
• a sleeve pivotally fitted in said fixing base and formed with a sleeve groove at the bottom, said sleeve groove having a slot provided at opposite sides of an opening of said sleeve groove:
• a wheel frame having its lower end axially assembled with a wheel and its upper end provided with a slide groove on opposite sides, a through hole provided above each said slide groove to be pivotally combined with said sleeve, said wheel frame having its top end inserted in said sleeve groove of said sleeve for moving together:
• a pin inserted in said slide groove of said wheel frame and having both ends protruding out of said slide groove, said pin having an intermediate portion clasped by one end of a spring, said spring having a second end connected to a cover member fixedly mounted on the top of said wheel frame, said pin being urged by said spring to push against the upper edge of said slide groove:
• wherein
• said wheel is moved outward by said pin urged by said spring, said wheel together with two other wheels forming a large triangular area to stabilize said golf cart.