Abstract:
A U-shaped bolt including a closed end and two legs at an open end is self-retaining on a first object. The U-shaped bolt includes projections forming an opening to the closed end adapted to be smaller than the width of the first object. The projections retain the U-shaped bolts on the first object. The U-shaped bolt is used in conjunction with a space heater having a plurality of heating elements connected by channels. The U-shaped bolt is retained on the channels to warrant proper assembly of the space heater.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention generally relates to secure mounting devices and more specifically relates to U-shaped attachment devices which include a closed end that securely fits on an object.  
       BACKGROUND  
       [0002]     U-shaped bolts are used in many different industries for attaching two objects. Typically, a first object is received within the closed end of the U-shaped bolt and the legs at the free end of the bolt are inserted through holes or notches in a second object. The bolt is then secured using nuts, clamps or the like to prevent the second object from being removed from the legs of the bolt. Often, the second object is a mounting plate which has other objects attached thereto, such that the other objects may be indirectly attached to the first object by means of the mounting plate and U-shaped bolt.  
         [0003]     U-shaped bolts are especially useful for attaching two objects when a very secure attachment is required and it is undesirable or impossible to place bores in the first object for conventionally bolting or screwing the objects together. For instance, U-shaped bolts are useful when the first object contains a liquid or gas. Accordingly, U-shaped bolts are a preferred means for attaching pipes to structures or, conversely, attaching objects to pipes.  
         [0004]     One drawback of conventional u-bolts is that there is no practical or convenient way to pre-set the u-bolt onto the first object. Unlike using a conventional bolt, which usually requires holes in both the first and second object, using a u-bolt does not require that the first object have any holes or other constraining geometry. Consequently, the user must hold the u-bolt in place while placing the second object on the legs. Further, the user must hold the u-bolt, first object and second object all in place, while attaching the nuts or the like to the legs.  
         [0005]     The fact that conventional u-bolts cannot be pre-set on the first object also leads to inconveniences in consumer goods where post-sale assembly is required. Products which require partial assembly on the part of the consumer should ideally be “error-proof” so that the parts include holes or other indicators showing where the conventional attachment members (i.e. bolts, nuts, screws, etc.) should be placed. A well designed product using conventional attachment members will only have one possible configuration that uses all of the attachment members. Thus, the consumer is constrained to use the attachment members appropriately. However, if the unassembled product includes a u-bolt there will be no hole or other indicator on the first object showing where to place the u-bolt. Consequently, the user may inadvertently place the u-bolt in an incorrect position on the first object.  
         [0006]     As an example, the space-heater  100  shown in  FIG. 1  has been correctly assembled. Space-heater  100  includes an end unit  110  including controls and the like and a plurality of elongated heat radiating elements  120  each with a top end  122  and a bottom end  124 . Space-heater  100  also includes channels  132  between each of the heating elements  120  at both the top end  122  and the bottom end  124 . When properly assembled, wheels  160  are attached to the bottom of the space-heater  100 . Conventional u-bolts  200  each receive two of the channels  130  at the bottom end  124  of space heater  100 . Support plates  150  each with a set of wheels  160  attached thereto are secured to the conventional u-bolts  200 . The wheels  160  are attached to the outermost channels  130  to provide a stable base for the space-heater  100 . The design of the space-heater  100  and conventional u-bolts  200  provide several plausible opportunities for the user to improperly assemble the space-heater. For example, one of the sets of wheels  160  may be placed on the inner channel  132 . Alternatively, the sets of wheels  160  may be attached to the upper end  122  of the space-heater  100  such that the space-heater  100  is used upside down.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention is directed to a U-shaped bolt having a novel design which allows the U-shaped bolt to be pre-set on a first object which it receives. The novel U-shaped bolts allow first and second objects to be assembled more easily and allows manufacturers to pre-set the U-shaped bolts on products which are sold unassembled.  
         [0008]     The U-shaped bolt of the present invention is an elongate structure which includes a closed end and an open end. The open end is defined by two legs. In use, a first object is received by the closed end and a second object is placed over the legs such that the legs pass through openings in the second object. Securing means are then placed on the legs such that the second object may not be easily or accidentally removed from the U-shaped bolt.  
         [0009]     The closed end of the U-shaped bolt may have a contour that conforms to the profile of the first object. Accordingly, the closed end may be circular, triangular, square, oval, or may be adapted to fit on any closed shape.  
         [0010]     The U-shaped bolt includes a projection between the apex of the closed end and the ends of the legs. The projection creates an opening to the closed end which is smaller than the widest inner dimension of the closed end of the U-shaped bolt. Thus, an appropriate first object may have a width which is larger than the opening such that the U-shaped bolt may be pre-set on the first object and not easily removed therefrom.  
         [0011]     The U-shaped bolt may be formed of any suitable material such as metals, plastics and composites, but should have some elasticity.  
         [0012]     To pre-set the U-shaped bolt, the legs are spread apart such that the open end is spread and the size of the opening is increased. The U-shaped bolt is then placed on the first object with the enlarged opening passing the widest part of the first object. The legs are then released and the opening returns to its original position. Consequently, the U-shaped bolt cannot easily be removed from the first object.  
         [0013]     A second object is then placed on the U-shaped bolt with the legs passing through openings in the second object. The second object is then held on the U-shaped bolt by retaining means such as clamps, nuts or an integrated retaining structure within the U-shaped bolt itself.  
         [0014]     One device which may take advantage of the U-shaped bolt is a space heater. The space-heater includes an end unit including controls and the like and a plurality of elongated heat radiating elements. The heat radiating elements each have a top end and a bottom end. Channels are provided between both the top ends and bottom ends of each heat radiating element. Support plates with wheels attached thereto are fixed to the space-heater using the U-shaped bolts. The closed ends of the U-shaped bolts receive the channels connecting the bottom ends of the heat radiating elements.  
         [0015]     Use of the U-shaped bolts with the space heater allows the unit to be sold unassembled but with the U-shaped bolts pre-set on the correct channels of the space heater. In a relaxed state the opening to the closed end of the U-shaped bolt is smaller than the diameter of the channel. Accordingly, the U-shaped bolt cannot be accidentally removed from the space heater. Thus, when the user attaches the support plate and wheels to the space heater there is no chance that the unit will be assembled incorrectly. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     These and other objects and features of the invention will become more apparent by referring to the drawings, in which:  
         [0017]      FIG. 1  is an illustration of a space-heater with wheels attached using conventional u-bolts;  
         [0018]      FIG. 2  is an illustration of a U-shaped bolt in accordance with the present invention;  
         [0019]      FIG. 3  is an illustration of an unassembled space-heater with pre-set U-shaped bolts of the present invention; and  
         [0020]      FIG. 4  is an illustration of an assembled space-heater including U-shaped bolts in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]     The U-shaped bolt  1  of the present invention, as shown in  FIG. 2 , is an elongate structure which includes a closed end  10  and an open end  20 . The open end  20  is defined by at least two legs  30 . In operation, a first object is received by the closed end  10  and a second object is placed over the legs  30  such that the legs  30  pass through openings in the second object. Securing means are then placed on the legs  30  such that the second object may not be easily or accidentally removed from the U-shaped bolt  1 .  
         [0022]     The closed end  10  of the U-shaped bolt  1  may have a contour  16  that forms to the profile of the first object. Accordingly, the closed end  10  may be triangular, square, oval, or may be adapted to fit on any closed shape. Most commonly, the first object will be circular, so as to engage a pipe. Therefore, the invention will herein be described with respect to an embodiment adapted for use with a circular first object.  
         [0023]     U-shaped bolt  1  includes a projection  50  between the apex  12  of the closed end  10  and ends  32  of the legs  30 . The projection  50  may be on one or both sides and may be a bent section of U-shaped bolt  1  as shown in  FIG. 2  or may be a flange or the like attached to the U-shaped bolt  1 . The bent portion may bend in toward the center of the U-shaped bolt. Another bend may also be included at the top of the leg  30  such that the legs  30  are parallel. The projection  50  creates an opening  54  which is smaller than the inner dimension  56  of the closed end  10  of the U-shaped bolt  1 . Thus, an appropriate first object  300  may have a cross-sectional width  320  which is larger than opening  54 , such that the U-shaped bolt  1  may be pre-set on the first object  300  and not easily removed therefrom.  
         [0024]     The U-shaped bolt  1  may be formed of any suitable material such as metals, plastics and composites, but should have some elasticity. Preferred embodiments include steel, aluminum and hard plastic.  
         [0025]     To pre-set U-shaped bolt  1 , legs  30  are spread apart such that the open end  20  is spread and the size of opening  54  is increased. The U-shaped bolt  1  is then placed on the first object  300  with the enlarged opening  54  passing over the width  320  of the first object  300 . The legs  30  are then released and the opening  54  returns to its original position. Consequently, the U-shaped bolt  1  cannot be easily removed from the first object  300  without again spreading the legs  30 .  
         [0026]     In its relaxed state, the contour  16  of the closed end  10  may be the same size or slightly larger than the profile  340  of the first object  300 . Alternatively, the contour  16  may be slightly smaller than the profile  340  of the first object  300 . As a result, the tension in the U-shaped bolt  1  will hold it firmly in place on the first object  300 .  
         [0027]     A second object is then placed on U-shaped bolt  1  with legs  30  passing through openings in the second object. The second object is then held on the U-shaped bolt by a retaining structure. The U-shaped bolt  1  may include any of a large variety of retaining structures. For example, clamps may be placed on the legs  30  opposite the closed end to prevent the second object from coming off. Alternatively, the legs  30  may include a bent foot  70  as shown in  FIG. 2  such that the foot holds the second object on the U-shaped bolt. In another embodiment the legs  30  may include threading  75  as shown in  FIG. 2  such that nuts or the like may hold the second object on the U-shaped bolt  1 .  
         [0028]     One device which may take advantage of the U-shaped bolt  1  is the space heater  100  shown in  FIG. 3 . As illustrated, the space-heater  100  includes an end unit  110  including controls and the like and a plurality of elongated heat radiating elements  120 . The heating elements each have a top end  122  and a bottom end  124 . Channels  130  are provided between both the top ends  122  and bottom ends  124  of each heat radiating element  120 . Support plates  150  with wheels  160  attached thereto are fixed to the space-heater  100  using U-shaped bolts  1 . The closed ends  10  of the U-shaped bolts  1  receives the channels  130  connecting the bottom ends  124  of heat radiating elements  120 . In one embodiment, the closed ends  10  are attached to the channels  130  toward the outside of the space heater  100 . This provides adequate stability for the space heater  100 .  
         [0029]     Use of the U-shaped bolts  1  with the space heater  100  allows the unit to be sold as shown in  FIG. 4 . The space heater  100  is unassembled but the U-shaped bolts  1  are pre-set on the correct channels  130  of the space heater  100 . In a relaxed state the opening  54  to the closed end  10  of the U-shaped bolt  1  is smaller than the diameter of the channel  130 . Accordingly, the U-shaped bolt  1  cannot be accidentally removed from the space heater  100 . Thus, when the user attaches the support plate  150  and wheels  160  to the space heater  100  there is no chance that the unit will be assembled incorrectly.  
         [0030]     Although the preferred form of the invention has been shown and described, many features may be varied, as will readily be apparent to those skilled in this art. The U-shaped bolt may be used to attach any number of objects. Similarly, the projection of the U-shaped bolt is not limited to a bent portion or a flange, but could also be a collar of other obstruction device. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.