Patent Publication Number: US-6905051-B2

Title: Protective case for use with a belt

Description:
BACKGROUND INFORMATION 
   1. Field of the Invention 
   The invention relates to the field of protective cases for handheld devices. More particularly, the invention relates to a protective case with a belt clip fastening system. 
   2. Description of the Prior Art 
   The user of a handheld device often carries the handheld device in a protective case. Typically, the protective case is constructed of a sturdy, rigid material that protects the handheld device from damage. Ideally, the user carries the device in a manner that makes it readily available for immediate use. This often means carrying the device attached to or close to the user&#39;s body. A common method of carrying the device within easy reach is to clip the protective case to the user&#39;s belt. There are numerous known ways of attaching the protective case to the user&#39;s belt. One such method is to provide a loop on the back of the case, through which the belt is then fed. This has the disadvantage in that it is inconvenient to remove the protective case without removing the belt. Another well-known method is to provide a belt clip on the back of the protective case. This allows the user to remove the protective case easily from the belt, but is disadvantageous in that the case is cumbersome when it is not on the belt, because of the appended belt clip. 
   Ideally, the protective case should be able to be used with or without a belt clip, thereby eliminating the need for a user to acquire a case with a belt clip and/or one without a belt clip. One way to provide this versatility is to construct the protective case with a means for removably attaching it to a belt clip. The belt clip is clipped to the belt and the protective case is then easily and quickly attachable to or detachable from the belt clip. A fastener system that would provide this versatility is that of a post that slips into a groove. Belt-clip fastening means are known that include a head on a post, wherein the post slides within a channel or groove on the belt clip and the head captured behind the groove. Fixedly attaching the post to the device or the case has the disadvantage in that the post cannot be disengaged from the case or device, thus leaving a protrusion on the case or device that may be a nuisance. 
   What is needed, therefore, is a protective case with a fastening means that enables removable attachment of the case to a belt clip. What is further needed is such a protective case with such a fastening means that avoids nuisance protrusions on the protective case. What is yet further needed is such a protective case with such a fastening means that is quickly and easily attached or detached from the case. 
   BRIEF SUMMARY OF THE INVENTION 
   For the reasons cited above, it is an object of the present invention to provide a protective case with a fastening means that enables removable attachment of the case to a belt clip. It is a further object to provide such a protective case with such a fastening means that avoids nuisance protrusions on the protective case. It is a yet further object to provide such a protective case with such a fastening means that is quickly and easily attached or detached from the case. 
   The objects of the invention are achieved by providing a protective case with a fastening means embedded in the case in such a way that the case may easily be attached to a belt clip. The case has a shell comprising hinged front and rear panels. When closed, the shell encloses and securely holds a handheld device. The shell is constructed of rigid material, such as a metal or a form-rigid material that protects the handheld device from damage if dropped. Such form-rigid material also includes leather or other materials that have sufficient stiffness and body to form the bubble and properly hold the nut in place. 
   The fastening means used in the protective case comprises a female-male threaded fastener. The female connector is a nut that is enclosed in a bubble on the rear panel and. The male connector is a post that has three sections: a threaded shaft, a support shaft, and a head. The threaded shaft threads into the nut and the support shaft, now extending from the rear panel, is slidingly insertable into a groove on a belt dip, such that the head is captured behind the groove. It is a key feature of the protective case according to the invention that the post is easily removable from the protective case by simply unscrewing it. Thus, if the user opts not to use a belt clip, the post does not present a nuisance protrusion that is a source of injury, or that can catch on clothing, and scratch or mar surfaces. 
   The bubble is the outer contour of a recess that is formed from the inner surface of the rear panel. The recess is shaped to correspond to the shape of the nut and, thus, to prevent the nut from rotating to any great extent when it is assembled in the back panel. So, if a square nut is used, the recess is square; if a triangular nut is used, the recess is triangular in shape. The recess forms a slight, smooth bubble on the outer surface of the rear shell panel. The smooth bubble is aesthetically pleasing in appearance and does not present any edges or protrusions that would catch on clothing or other objects. A hole is bored through the center of the bubble or recess, allowing threaded shaft of the post to be inserted through the hole and fastened in the nut. 
   In order to facilitate easy removal of the post from the shell, a concave curved slot is provided in the head, thus enabling the user to fasten/unfasten the post with the use of a coin. The post must attach firmly to the case, in order to reliably support the case with the handhold device in it from the belt clip. A washer is provided that secures the post to the case. 
   The inner surface of the shell is covered with a backing and this backing, in addition to protecting the encased handheld device from being scratched or damaged, also serves as a practical means for retaining the nut in the recess. Ideally, the backing is of a material that provides an aesthetic covering that is pleasant to the touch and also provides some shock absorption, should the encased handheld device be dropped. Examples of appropriate backing materials include non-woven fabrics, natural or synthetic fabrics, such as rubber, neoprene, suede leather, etc. It should be understood that many types of material are suitable for the backing, including metal, a rigid backing plate, or composite constructions of materials. The primary requirement of the backing material is that it be strong enough to prevent the nut from falling out of the recess or shifting away from the shell toward the inner area of the case, so that it becomes difficult or impossible to thread the post into the nut. 
   The protective case according to the invention is suitable for use with many different types of handheld devices such as PDAs, MP3 players and cell phones, i.e., any handheld device. To prepare the protective case for attachment to a belt clip, the threaded shaft is inserted into the recess and threaded into the nut. The post now protrudes from the case. The head of the post is easily and quickly captured in the belt clip by sliding the body into the groove. To remove the case from the belt clip, the post is simply slid out of the groove. To use the protective case without the belt clip, the post is easily removed from the case leaving only the smooth bubble on the outer surface of the rear panel. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears. 
       FIG. 1  is a side elevational view of the protective case, according to the invention, showing the case attached to a belt clip. 
       FIG. 2  is a cross-sectional view of the rear panel of the protective case of  FIG. 1  showing the fastening means. 
       FIG. 3  is a planar view of the rear panel of the protective case of  FIG. 1 , with the fastening means removed. 
       FIG. 4  is a planar view of the belt clip showing a channel for the post. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1 and 2  illustrate a protective case  100  according to the invention.  FIG. 1  shows the protective case  100  suspended from a belt clip B. The protective case  100  comprises a shell  101  and a removable fastening means  104 . The shell  101  includes a rear panel  103 , a front panel  111  and a hinge  109 . The rear panel  103  has an outer surface  103 A and an inner surface  103 B. The fastening means  104  comprises a female connector  105 , a male connector  107  and a washer  105 . The female connector is hereinafter referred to as a “nut” and the male connector as a “post.” The post  104  includes a threaded shaft  107 C, a support shaft  107 A and head  107 B. A concave area or recess  102 , with a convex area or corresponding bubble  113 , is formed in the rear panel  103 . The bubble  113  is a smooth, raised contour on the outer surface  103 A. A through-bore  110  is provided through the center of the bubble  113 , as shown in FIG.  2 . The shell  101  is preferably constructed of a rigid material such a metal or a form-rigid synthetic or rubber material, although other materials, such as leather, may also be suitable. 
     FIG. 2  is a cross-sectional drawing that shows the post  104  ready for insertion into the nut  105  that is assembled in the recess  102 . The nut  105  is dimensioned such that, when placed in the recess  102 , the upper surface is substantially aligned with the plane of the inner surface  103 B. The recess  102  is shaped to correspond to the shape of the nut  105 , to prevent the nut from rotating in the recess  102 . Thus, if the nut is square, the recess is a square recess; it the nut is triangular, the recess is triangular. The shaft  107 C of the post  107  may then be threaded through the washer  108  and the hole  110  and into the nut  105 . The washer  108  is permanently affixed to the post  107  directly below the support shaft  107 A around the threaded shaft  107 C so that it cannot be lost. The washer  108  serves to secure the post  107  to the bubble  113  when tightened and also to protect the outer surface  103 A from being scratched or other marred by the post  107 . Preferably, the washer  108  is a composite construction with a soft layer  1085  that faces the outer surface  103 A, provides greater friction force against the shell  101 , and prevents surface damage to the shell  101 , and with a hard layer  108 A that faces the support shaft  107 A and provides the strength and rigidity to secure the post  107  to the shell  101 . Suitable materials for the soft layer  108 B include but are in no way limited to nylon, leather, and felt. The circumferential side of the head  107 B has a knurled or embossed surface that facilitates gripping and turning. Cut across the top surface of the head  1078  is a slot  107 D, shown with dashed lines in  FIG. 2 , to enable the use of a coin to tighten/untighten the post  104 . The slot  107 D is convexly curved, to increase surface contact between the head  1078  and the coin. 
   With continued reference to  FIG. 2 , the inner side  103 B of the rear panel  103  is covered with a backing  112 , at least in the area surrounding and covering the recess  102 . The backing  112  serves several purposes. It provides a protective surface for a device that is encased in the protective case  100 , and also serves to hold the nut  105  in place in the recess  102 . Many types of material are suitable for the backing, as long as the material is strong enough to prevent the nut  105  from falling out of the recess  102  or from shifting away from the inner surface  103 A of the rear panel  103 , thereby making it difficult or impossible to thread the threaded shft  107 C into the nut  105 . Suitable backing materials include woven or non-woven fabrics of natural or synthetic materials and combinations thereof, for example, neoprene, rubber, supple leather, a rugged woven cotton fabric, etc. Ideally, the backing  112  also provides an aesthetic covering that is soft and pleasing to the touch and/or provides some shock absorption ability. 
     FIG. 3  is a planar view of the rear panel  103  of the protective case  100  according to the invention, without the fastening means  104  attached, showing the through-bore  110  through the bubble  113 .  FIG. 4  shows a planar view of the belt clip B, showing an arm  106  and a groove  106 A in which the support shaft  107 A of the post  104  is receivable. As mentioned above, the fastening means  104  is quickly and easily removable from the protective case  100 . To assemble the fastening means  104  onto the shell  101 , the threaded shaft  107 C is inserted through the through-bore  110  in the bubble  113 , threaded into the nut  105  and tightened. The washer  108 , being attached to the post  107 , is automatically positioned over the through-bore  110  and protects the shell  101  from damage. The belt clip B comprises an arm  106 , shown in  FIG. 1 , with a groove  106 A shown in FIG.  5 . The support shaft  107 A of the post  107  slides into the groove  106 A, placing the arm  106  between the washer  108  and the head  107 B of the post  107 . The head  107 B is wider than the width of the groove  106 A and is thus captured behind the groove. To remove the protective case  100  from the belt clip B, the post  104  is simply slid upward and the head  107 B released from the groove. 
   It is understood that the embodiments described herein are merely illustrative of the present invention. Variations in the construction of the post fastener may be contemplated by one skilled in the art without limiting the intended scope of the invention herein disclosed and as defined by the following claims.