Patent Publication Number: US-6663263-B2

Title: One-piece collapsible lampshade

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a lampshade, particularly to a collapsible lampshade which has a flexible cover supported by a foldable frame. 
     2. Description of the Related Art 
     Lampshades are normally bulky and occupy large spaces during transport and storage. In order to reduce the spaces required by lampshades during transportation or storage, the prior art has suggested various forms of collapsible lampshades which can be kept in a compact size when collapsed. In one type of collapsible lampshade, separate multiple frame parts are provided for assembly into a lampshade frame, and a flexible lampshade cover is fitted over the lampshade frame. Since the frame parts and the lampshade cover are separated before assembly, they can be packed into a compact size to facilitate transport and storage. Another type of collapsible lampshade is produced by providing multiple complementary parts each having a frame part integral with a lampshade cover. The complementary parts can be stacked to reduce the lampshade size and can be interconnected to form a lampshade. Nevertheless, in either type of collapsible lampshade, there is a risk of loosing parts, or damage during shipment due to the movement of loose parts against one another. 
     In order to alleviate the aforesaid problems, U.S. Pat. No. 6,315,434 suggests a one-piece collapsible lampshade in which a frusto-conical flexible lampshade cover is integrated with a collapsible frame. The frame includes an upper ring attached to an upper end of the lampshade cover, a lower ring attached to a lower end of the lampshade cover, and a plurality support rods each having one end permanently and pivotally attached to the lower ring and another end removably inserted into a receptacle fixed to the upper ring. When the support rods are removed from the upper ring, both of the frame and cover are collapsed to a substantially flat configuration so that the lampshade can be kept in a compact size as a whole without separation. However, inconveniences are encountered when the support rods are to be attached to the upper ring to place the frame in an uncollapsed state because a considerable amount of energy is required to push or pull the upper ring away from the lower ring against the tension of the flexible cover so as to insert the support rods into the respective receptacles mounted on the upper ring. In addition, the force applied to the upper ring must keep the upper ring balanced in order to ensure extension of the support rods into the respective receptacles. 
     U.S. Pat. No. 5,375,048 discloses a collapsible frame which is comprised of upper and lower rings, and a plurality of rib members each having two ends respectively pivoted to the upper and lower rings. Each rib member has a hinge at its middle part and is thus foldable to permit the frame to lie flat with the upper and lower rings stacked. The frame additionally includes a slider disposed around each rib and slidable along the rib to move over and away from the hinge. 
     When each slider moves over the corresponding hinge, each rib is locked from its folding movement so that the frame can be stretched to an uncollapsed state. The frame further includes a spider disposed between the upper and lower rings to operate the sliders. This collapsible frame requires extra components to lock the frame in a stretched state and thus has a complicated construction. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a collapsible lampshade with a simple construction in which foldable ribs can be unfolded and locked in a stretched operative state without the need to provide extra components. 
     Accordingly, a lampshade of the present invention comprises: an upper ring; a lower ring; a plurality of upper ribs each having a first end pivoted to the upper ring, and a second end part; a plurality of lower ribs each having a third end pivoted to the lower ring and a fourth end part, the fourth end part having a connection part pivoted to the second end part, the connection part having a pair of flaps extending over two opposite sides of the second end part and pivoted to the second end part; and releasable interengagement elements formed on the flaps and the second end part to engage the second end part with the flaps and to lock the second end part from movement relative to the flaps. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which: 
     FIG. 1 is a perspective view of a collapsible lampshade embodying the present invention; 
     FIG. 2 is a fragmentary perspective view showing a connection between upper and lower ribs of the collapsible lampshade of FIG. 1; and 
     FIG. 3 is an elevation view showing the collapsible lampshade in a folded state. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a lampshade  1  embodying the present invention is shown to include a frusto-conical flexible cover  10  made of a fabric material, and a collapsible frame  20  made of a metal. The frame  20  includes an upper ring  21 , a lower ring  22  greater than the upper ring  21 , a plurality of upper and lower ribs  23 ,  24 . The flexible cover  10  has upper and lower ends  11 ,  12  which are folded and fixed, respectively, to the upper and lower rings  11 ,  12  in a conventional manner. 
     Each of the upper and lower rings  21 ,  22  has a plurality of spaced apart pivot seats  25  projecting therefrom. Each upper rib  23  has one end  231  pivoted to the corresponding pivot seat  25  of the upper ring  21 , and each lower rib  24  has one end  241  pivoted to the corresponding pivot seat  25  of the lower ring  22 . Another end part  232  of each upper rib  23  is connected pivotally to another end part  242  of the corresponding lower rib  24  by means of a connection part  30 , as shown in FIG.  2 . The connection part  30  has a generally U-shaped cross-section and may be formed as one piece with or as a separate piece from the end part  242  of the corresponding lower rib  24 . In this embodiment, the connection part  30  in the form of a separate piece is used and includes a pair of substantially parallel flaps  301  interconnected by a bight portion  302 . 
     The connection part  30  has one end portion  31  receiving the end part  242  of the corresponding lower rib  24  and another end portion  32  opposite to the end portion  31 . The end portion  31  is connected rigidly to the end part  242  of the lower rib  24  via rivets  33 . The end part  232  of the corresponding upper rib  23  extends between the flaps  301  and is pivoted to the connection part  30  between the end portions  31  and  32  via a pin  35 . As a result, the upper rib  23  is turnable relative to the lower rib  24  so as to fold over the lower rib  24 . Since the upper ribs  23  are foldable over the lower ribs  24 , the upper ring  21  is permitted to move toward the lower ring  22  and the frame  20  can be collapsed to a state as shown in FIG.  3 . 
     The frame  20  is further provided with interengagment elements, which are formed as a pair of protrusions  41  and a pair of recesses  42 , as shown in FIG.  2 . The pair of protrusions  41  respectively project inward from inner surfaces of the flaps  301 , and the pair of recesses  42  are respectively formed in two opposite sides of the end part  232  of the upper rib  23 . Note that each connection part  30  has an open side  303  that faces in a direction towards the outside of the frame  20 , and the bight portion  302  extends inwardly of the open side  303 . 
     When the lampshade  1  is to be used, the frame  20  is stretched to an operative state by moving the upper ring  21  away from the lower ring  22  and by pushing the end part  232  of each upper rib  23 , or the end part  242  of each lower rib  24 , or each connection part  30  along a radially outward direction as shown by arrows (A) in FIG.  1 . In this situation, the bight portion  302  of each connection part  30  abuts against an inner side of the corresponding upper rib  23 , and the protrusions  41  on each connection part  30  respectively engage the recesses  42  of the corresponding upper rib  23 . As a result, the upper ribs  23  are locked from folding over the respective lower ribs  24  and the frame  20  is placed in a stretched operative state, as shown in FIG.  1 . 
     As described above, the frame  20  can be stretched or locked in its stretched state by simply pushing outward the upper ribs  23  and/or the lower ribs  24  near or at the connection parts  30 . When the upper ribs  23  and/or the lower ribs  24  are pushed inward, the frame  20  can be folded. It can be appreciated that the collapsible lampshade  1  is constructed with fewer component parts and can be folded or unfolded in a simple manner with less effort as compared to the conventional collapsible lampshades described hereinbefore. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.