Patent ID: 8079563

Claim:
An elevating mechanism comprising: a sleeve comprising a first end and a second end; an elevating component installed inside the sleeve in a movable manner relative to the sleeve, the elevating component comprising a third end and a fourth end, a first distance between the first end of the sleeve and the third end of the elevating component being larger than a second distance between the second end of the sleeve and the fourth end of the elevating component; a main spring connected to the sleeve and the elevating component, the main spring being compressed by the elevating component at a first deformation when the elevating component is located in a first position relative to the sleeve, the main spring being compressed by the elevating component at a second deformation when the component is located in a second position relative to the sleeve, and the first deformation being larger than the second deformation; and a complementary spring comprising a fifth end contacting with an inner side of the sleeve and a sixth end contacting with the elevating component, the complementary spring being compressed at a third deformation when the elevating component is located in the first position relative to the sleeve, the complementary spring being compressed at a fourth deformation when the component is located in the second position relative to the sleeve, and the third deformation being greater than the fourth deformation.