Swivelling shield providing protection to fan

Abstract

A shield for a fan includes a mounting frame, a receiving frame and a mounting plate. A plurality of shielding pieces is pivotally mounted on the mounting frame. The receiving frame receives the mounting frame. The receiving frame includes a bottom edge containing a weight block. The mounting plate defines a vent hole. The receiving frame is pivotally mounted on the mounting plate and aligned to the vent hole. Gravity of the weight block causes the bottom edge to be always in a horizontal direction and the undermost position of the receiving frame.

What is claimed is: 
     
         1 . A shield for a fan, comprising:
 a mounting frame, a plurality of shielding pieces pivotally mounted on the mounting frame;   a receiving frame receiving the mounting frame mounted therein, the receiving frame comprising a bottom edge, and a weight block mounted on the bottom edge; and   a mounting plate defining a vent hole, the receiving frame pivotally mounted on the mounting plate and aligned with the vent hole;   wherein gravity of the weight block is configured to contain the bottom edge in a horizontal direction and the undermost position of the receiving frame.   
     
     
         2 . The shield of  claim 1 , wherein a post is secured in a center portion of the vent hole, the receiving frame defines a pivot hole, and the post is povitally mounted in the pivot hole. 
     
     
         3 . The shield of  claim 2 , wherein each of four corners of the mounting plate comprises a positioning member, and the positioning member abuts the receiving frame. 
     
     
         4 . The shield of  claim 3 , wherein the positioning member comprises a spring and a ball, the spring is abuts the ball, the positioning member defines a through hole, a size of the through hole is smaller than a diameter of the ball, and part of the ball extends out of the positioning member via the through hole to abut the receiving frame. 
     
     
         5 . The shield of  claim 4 , wherein each of four corners of the receiving frame defines a recess, and the ball is configured to be positioned in the recess. 
     
     
         6 . The shield of  claim 4 , wherein the positioning member comprises a first receiving case and a second receiving case, the first receiving case defines a first receiving room, the second receiving case defines a second receiving room, and the first receiving room and the second receiving room together receive the spring and the ball therein. 
     
     
         7 . The shield of  claim 6 , wherein a side of the first receiving case defines a semicircular first cutout, a side of the second receiving case defines a semicircular second cutout, widths of the semicircular first cutout and the semicircular second cutout are smaller than the diameter of the ball, and the semicircular first cutout and the semicircular second cutout together form the through hole. 
     
     
         8 . The shield of  claim 7 , wherein the first receiving case comprises a plurality of locks, the second receiving case comprises a plurality of locking holes, and the plurality of locks are engaged in the plurality of locking holes to secure the first receiving case and the second receiving case together. 
     
     
         9 . The shield of  claim 1 , wherein the plurality of shielding pieces of the mounting frame is kept in the horizontal direction. 
     
     
         10 . A shield, comprising:
 a receiving frame with a plurality of horizontal shielding pieces pivotally mounted thereon, the receiving frame comprising a bottom edge which extends in a horizontal direction, a weight block mounted on the bottom edge; and   a mounting plate defining a vent hole, the receiving frame pivotally mounted on the mounting plate and aligned with the vent hole;   wherein gravity of weight block is configured to contain the bottom edge in a horizontal direction and at the undermost position of the receiving frame.   
     
     
         11 . The shield of  claim 10 , wherein a post is secured on a center portion of vent hole, the receiving frame defines a pivot hole, and the post is pivotally mounted in the pivot hole. 
     
     
         12 . The shield of  claim 11 , wherein each of four corners of the mounting plate comprises a positioning member, and the positioning member abuts the receiving frame. 
     
     
         13 . The shield of  claim 12 , wherein the positioning member comprises a spring and a ball, the spring abuts the ball, the positioning member defines a through hole, a size of the through hole is smaller than a diameter of the ball, and part of the ball extends out of the positioning member via the through hole to abut the receiving frame. 
     
     
         14 . The shield of  claim 13 , wherein each of four corners of the receiving frame defines a recess, and the ball is configured to be positioned in the recess. 
     
     
         15 . The shield of  claim 13 , wherein the positioning member comprises a first receiving case and a second receiving case, the first receiving case defines a first receiving room, the second receiving case defines a second receiving room, and the first receiving room and the second receiving room together receive the spring and the ball therein. 
     
     
         16 . The shield of  claim 15 , wherein a side of the first receiving case defines a semicircular first cutout, a side of the second receiving case defines a semicircular second cutout, widths of the semicircular first cutout and the semicircular second cutout are smaller than the diameter of the ball, and the semicircular first cutout and the semicircular second cutout together form the through hole. 
     
     
         17 . The shield of  claim 16 , wherein the first receiving case comprises a plurality of locks, the second receiving case comprises a plurality of locking holes, and the plurality of locks are engaged in the plurality of locking holes to secure the first receiving case and the second receiving case together. 
     
     
         18 . The shield of  claim 10 , wherein the weight block is mounted on a center portion of the bottom edge.