Abstract:
A releasable hinge for attaching tonneau covers to the cargo compartment of pickup trucks. The hinge has a hinge mechanism fastened to the bottom or underside of the tonneau cover. A complementary locking tab is mounted to the cab end of the cargo compartment. The hinge mechanism has a plate with a locking tongue that is received in a locking channel in the locking tab to latch the tonneau cover to the cargo compartment. To remove the tonneau cover from the cargo compartment, the tonneau cover is raised above a predetermined angle which disengages the locking tongue from the locking channel. This allows the hinge to separate from the locking tab. Any gas struts are released from their mounting brackets and the tonneau cover can be removed from the cargo compartment.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based on and claims priority of provisional patent application 60/731,130 filed Oct. 28, 2005. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to a hinge mechanism for releaseably attaching tonneau covers to the cargo compartment of pickup trucks. 
     Pickup trucks have rectangular shaped beds at the rear of the vehicle, generally with a pivoting tailgate that pivots downwardly and in a rearward direction to a flat, horizontal plane that is generally in the same plane as the floor of the bed. Pickup trucks are used for numerous purposes for hauling all types of articles that vary in size, shape and weight. At times it is beneficial that the bed be covered to protect the articles being transported. 
     Various covers have been used in the past. There are essentially two types of covers. One type is comprised of flexible covers including canvas, other fabrics and flexible vinyl covers. The flexible cover is secured to the pickup truck by ropes, flexible cords and other straps that are secured by hooks, ties, snaps and other fasteners. These types of covers are unsatisfactory in that they are extremely time consuming to put in place and secure to the truck, with a similar amount of time required to remove them. Due to the flexible characteristics of the cover, they allow water to pool in low spots, rather than run off and onto the ground. Due to their lack of structural strength, they do not permit the user to walk on them or to install other items, such as racks, onto the flexible cover. 
     As an alternative to flexible cover, a second type of cover, also called a tonneau cover, has gained popularity. These are rigid covers comprised of one piece rigid covers and multi-piece sectional rigid covers. Metal and rigid plastic covers have been introduced and are usually pivotally connected to the front portion of the cargo compartment or bed. These allow the user to raise the cover from the rear of the bed, place the items in the bed, and lower the cover to protect the items. Generally hinges and other connectors are used to connect the cover to the truck bed or truck body. These connectors are not readily or easily removed if the cover is to be removed from the cargo bed for additional storage space. Thus, there is not a quick and convenient attachment means for easily and quickly attaching and removing rigid tonneau covers from the cargo compartment. 
     U.S. Pat. No. 6,447,045 issued to Dickson et al. illustrates a tonneau cover mounting system that utilizes a pair of hinges mounted on opposite sides of the truck bed. The hinge mechanism allows the cover to pivot away from the cab as it is opened to allow for the cover to be mounted close to the cab. However, this device does not illustrate a means for easily detaching the cover from the truck bed or for easy re-attachment. 
     Other prior art patents that illustrate various tonneau covers are U.S. Pat. Nos. 6,547,310 and 6,857,683 both issued to Myers and U.S. Pat. No. 6,340,194 issued to Muirhead et al. None of these patents address the problem of easily removing and then re-attaching the tonneau cover to the truck bed. In fact, none of these patents even address the problem of easily attaching and removing the tonneau cover from the truck bed. They merely describe a hinge attachment at the front of the cover for pivotally attaching the cover to the truck bed. 
     SUMMARY OF THE INVENTION 
     Applicant&#39;s releasable hinge has a hinge mechanism mounted to the tonneau cover that is separable from a complementary locking tab mounted to the truck bed at the cab end of the truck bed. The hinge mechanism has a top plate portion mounted to the tonneau cover and another portion of the hinge mechanism releaseably attached to a complementary locking tab mounted to the truck bed. The hinge mechanism has a mid plate with a locking tongue that is received in a locking channel in the locking tab to latch the tonneau cover in place on the truck bed. To remove the tonneau cover, the rear portion of the tonneau cover is raised above a predetermined angle, generally greater than approximately 23°, which releases the locking tongue from the locking tab. If the cover has gas struts to assist in opening and closing the tonneau cover, at least one end is released from its attachment means. Once the locking tongue disengages from the locking tab, the hinge portion attached to the tonneau cover can separate from the locking tab which allows the tonneau cover to be removed. 
     OBJECTS AND ADVANTAGES 
     Thus, it is an object of the invention to provide an attachment means for easily attaching and removing a rigid tonneau cover to a truck bed. It is another object to provide an attachment means that once installed to the truck bed and tonneau cover, allows the tonneau cover to be attached and removed without tools. Related to this object is to provide a releasable attachment means that does not interfere with the tonneau cover pivoting to an open position to access the storage bed. These and other objects and advantages will be apparent from reading the Description of the Preferred Embodiment. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the inventive hinge mechanism connecting a tonneau cover to a truck bed. 
         FIG. 2  is a side view with portions removed of the tonneau cover in a raised position with respect to the truck bed with the inventive hinge mechanism in the latched position attaching the tonneau cover to the truck bed. 
         FIG. 3  is rear perspective view of the hinge mechanism. 
         FIG. 4  is a front view of the hinge mechanism. 
         FIG. 5  is a front perspective view of the hinge mechanism. 
         FIG. 6  is a side view with portions removed of the hinge mechanism in the closed position mounted on the front frame member that is mounted to the truck bed. 
         FIG. 7  is a side view with portions removed of the hinge mechanism in the open position mounted on the front frame member that is mounted to the truck bed. 
         FIG. 8  is a side view with portions removed of the hinge mechanism in the open removal position with the hinge mechanism unlatched from the front frame member that is mounted to the truck bed. 
         FIG. 9  is a front perspective view of the hinge mechanism. 
         FIG. 10  is a perspective view of the hinge mid plate. 
         FIG. 11  is an end view of the hinge mid plate. 
         FIG. 12  is a top plan view of the hinge mid plate. 
         FIG. 13  is a cross sectional view taken along line  13 - 13  of  FIG. 12  of the hinge mid plate. 
         FIG. 14  is a perspective view of the hinge bottom plate. 
         FIG. 15  is a side view of the hinge bottom plate. 
         FIG. 16  is an end view of the hinge bottom plate. 
         FIG. 17  is a perspective view of the hinge top plate. 
         FIG. 18  is a side view of the hinge top plate. 
         FIG. 19  is a top plan view of the hinge top plate. 
         FIG. 20  is a perspective view of the split pivot pin. 
         FIG. 21  is a top plan view of the light torsion spring. 
         FIG. 22  is a perspective view of the heavy torsion spring. 
         FIG. 23  is a perspective view of the front mounting frame that is attached to the truck bed. 
         FIG. 24  is a front view of the front mounting frame that is attached to the truck bed. 
         FIG. 25  is a top plan view of the front mounting frame that is attached to the truck bed. 
         FIG. 26  is an enlarged view of the circled portion marked “A” in  FIG. 25  showing the locking tab on the front mounting frame. 
         FIG. 27  is a cross section view of the front mounting frame taken along line  27 - 27  of  FIG. 24 . 
         FIG. 28  is an enlarged view of the hinge top plate fastened to the tonneau cover. 
         FIG. 29  is a perspective view of the front mounting frame showing its orientation over the truck bed prior to its installation. 
         FIG. 30  is a perspective view with portions removed of the front mounting frame showing how it is fastened to the front of the truck bed. 
         FIG. 31  is a perspective view of the tonneau cover positioned on the truck bed prior to its being moved horizontally into the latched position. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Turning first to  FIG. 1 , there is illustrated a tonneau cover  10  in its opened or raised position over a cargo bed  12  of a pickup truck. The cover  10  has a smooth top surface  14  with side overhanging edges  16  and a front and rear overhanging edge  18  and  20 . Grain, texture or various surface geometries and patterns can be formed into the top surface  14 . The overhanging edges  16 ,  18  and  20  extend over upstanding walls  22  of the cargo bed  12  so that water runs off the top surface  14  and does not enter into the cargo bed  12 . Gas charged or air cylinders  24  control the speed at which the cover  10  is raised and lowered. They can also assist in keeping the cover  10  in the raised position until the user desires to lower the cover  10  to cover the cargo bed  12 . They further restrict the height to which the tonneau cover  10  can be raised. The cargo bed  12  has a front end  26  adjacent to the truck cab and a tailgate  28  at a rear end. 
       FIG. 2  illustrates the tonneau cover  10  partially in cross section in its opened position. A hinge mechanism  30  pivotally connects the tonneau cover  10  to the cargo bed  12  adjacent to the front end  26 . There is a front frame  32  attached to the front end  26 . The front frame extends across the front end  26  and partially around opposite side  34  of the cargo bed  12 . The hinge mechanism  30  is comprised of a bottom plate  36 , a mid plate  38  and a top plate  40 , which will be more fully described later. 
       FIGS. 3 ,  4  and  9  illustrate the hinge mechanism  30  in greater detail. The bottom plate  36  is comprised of opposite bottom plate sides  42  and a bottom  44  such that it is generally of a u-shaped configuration. This is seen in FIGS.  3  and  14 - 16 . Each side  42  has a pin hole  46  passing through the side  42 . There is an entrance channel or elongated open slot  47  at one end of the hinge mechanism  30  which is at the front end  18  of the tonneau cover  12 . 
       FIGS. 3 ,  4  and  9 - 13  illustrate the mid plate  38  in greater detail. There is a mid plate bottom  48  having a centrally disposed locking tongue or latch  50 . The locking tongue  50  extends from approximately the center of the bottom plate  48  downward such that a distal end  52  extends below the bottom of the mid plate bottom  48 . There are upright mid plate side walls  54  at opposite sides of the mid plate bottom  48  such that the end view of  FIG. 11  shows the mid plate  38  being generally u-shaped. There are pin holes  56  in each of the mid plate side walls  54 . There is a mid plate curved back  58  at the proximal end of the mid plate bottom  48  which is opposite the distal end  52  of the locking tongue  50 . 
       FIGS. 3 ,  4 ,  9  and  17 - 19  also illustrate the components of the top plate  40 . There is a proximal end  60  having a top plate curved back  62 . Also at the proximal end  60  is a pair of opposite top plate side walls  64  with pin holes  66  passing through the side plate walls  64 . Passing through the top plate  40  are a plurality of fastener holes  68 . As seen in  FIG. 18  the top plate  40  drops down from the proximal end  60  and then extends at a slightly upward angle to a distal end  70 . Fasteners such as screws, bolts, rivets, or other generally known fasteners pass through the fastener holes  68  and attach the top plate  40  to the tonneau cover  10  as seen in  FIG. 27 . 
       FIG. 4  illustrates the assemblage and the pivoting relationship of the individual hinge mechanism components. A split pin  72  with a split end  73  ( FIG. 22 ) extends through the pin holes  46  in the bottom plate sides  42 , then through the pin holes  66  in the top plate side walls  64 , and through the pin holes  56  in the mid plate side walls  54 . There are locking end caps  74  to securely keep the split pin  72  within the hinge mechanism  30 . The bottom plate  36 , mid plate  38  and top plate  40  all rotate, within rotational limitations, about the split pin  72 . The entrance channel  47  leads into a channel or gap  75  which is formed between the bottom plate  36  and the mid plate  38 . The locking tongue  50  extends into this channel or gap  75 . 
     A light duty torsion spring  76  having opposite ends  78  ( FIG. 21 ) is wrapped around the split pin  72  as seen in  FIGS. 3-5 . The spring  76  assists in forcing the locking tongue  50  in a downward direction as will be described in greater detail herein. A heavy duty torsion spring  80  is also wrapped around the split pin  72  and has one end  82  inserted into the split end  73  and an opposite end  84  secured to the top plate curved back  62  (see  FIG. 3 ). The purpose of the heavy duty torsion spring  80  is to provide a closing force to assist in pulling the top plate  40  towards the bottom plate  36  to facilitate installation of the tonneau cover  12  while the tonneau cover  12  is in the flat, horizontal or down position. 
     A front frame  86 , which is illustrated in  FIGS. 23-25 , is mounted to the front end  26  of the cargo bed  12  as seen in  FIG. 29 . The front frame  86  is the complementary portion of the hinge which receives the hinge mechanism  30  as illustrated in  FIGS. 6-8 . The front frame  86  has a pair of side mounting rails  88  that attach to the upstanding walls  22  on the cargo bed sides  34 . The side mounting rails  88  are preferably attached by clamps rather than drilling holes in the cargo bed sides  34 . Such clamps are commonly known and available in the industry.  FIG. 30  illustrates one such method. Grooves or slots  87  are cut in the sides rails  88 . A pair of C-clamps  89  is place behind a truck rail lip  91  that extends around the cargo bed  12 . Bolts  93  pass through the grooves  87  and are fastened to the C-clamps  89  to secure the front frame  86  to the cargo bed  12 . 
     A pair of locking tabs  90  is located on the front frame  86 . As seen in  FIGS. 6 ,  25 , and  27 , the tabs  90  extend up from the front frame  86  and then turn back over the front frame  86  in a u-shaped configuration with a leading end  92 . This creates an opening or gap  94  between a top surface  96  of the front frame  86  and the locking tab  90 . The locking tab  90  has locking means illustrated as a locking channel or opening  98  that is generally rectangular in shape within the locking tab  90 . Other shaped openings or recesses can be utilized as the locking means for receiving the locking tongue  50 . 
     To use the hinge mechanism, the user first securely attaches the front frame  86  to the front end  26  or the cargo bed  12  as described above and seen in  FIGS. 29 and 30 . Alternatively the front frame can be mounted by drilling holes through the front frame  86  and the cargo bed  12  and fastening bolts passed there through. The tonneau cover  10  either has the hinge mechanism  30  already attached to it or the user attaches it to the tonneau cover by fastener means passing through the fastener holes  68  in the top plate  40  into the tonneau cover  10  as previously described and as seen in  FIG. 28 . The two hinge mechanisms  30  must be separated from each other the same horizontal distance that the locking tabs  90  are separated from each other. Furthermore the two hinge mechanisms  30  must be aligned with their respective locking tables  90 . 
     The installation of the tonneau cover  10  is seen in  FIG. 31 . With the hinge mechanisms  30  mounted to the tonneau cover, the tonneau cover  10  is raised above and then gently placed on the upstanding walls  22  of the cargo bed  12  with the rear overhanging edge  20  of the tonneau cover  12  extending past the tail gate  28 . This results in the entrance channel  47  for each of the hinge mechanisms  30  being separated from but in alignment with their respective locking tab  90 . 
     The tonneau cover  10  is slid forward in the direction of arrow B toward the front end  26  of the cargo bed with the locking tabs  90  in alignment with the entrance channels  47  of the hinge mechanisms  30 . The leading end  92  of the locking tab  90  is received in the entrance channel  47  and then slides into the channel  75 . The bottom plate  36  slides into the gap  94 . The leading end  92  engages the underside of the locking tongue  50  which is biased downwardly due to the force exerted on it by the light duty torsion spring  76 . The force of insertion of the locking tab  90  overcomes the slight force of the light duty torsion spring  76  which forces the locking tongue  50  upward. Once the leading end  92  passes the distal end  52  of the locking tongue  50 , gravity and the force from the light duty torsion spring  76  forces the locking tongue  50  into the locking channel  98 . In this position the hinge mechanism  30  is now securely latched into the front frame  86  and cannot be removed by exerting a horizontal force in the rear direction as the locking tongue  50  engages the locking channel  98  which restricts horizontal movement in the rear direction. Likewise, the tonneau cover cannot move forward as the locking tabs  90  restrict any further forward movement of the tonneau cover  10 . The gas or air cylinders  24 , which are attached to the tonneau cover  10 , are attached to the bed sides  34  in a conventional manner such as a removable clamping bracket or permanently affixed mounting brackets. 
     With the tonneau cover  10  in the closed position, the hinge mechanism  30  is in the position illustrated in  FIGS. 3 and 6 , with the tonneau cover  10  removed for clarity. There is a separation or space  100  between a lower edge  102  of the top plate curved back  62  and an upper edge  104  of the mid plate curved back. To release or unlatch the tonneau cover  10  from the locking tabs  90 , the tonneau cover  10  is first raised to the fully open position such as seen in  FIG. 1 . The cylinders  24  restrict the height that the tonneau cover  10  can be raised. As seen in  FIG. 7 , the separation or space  100  disappears. This is due to the top plate pivoting upward causing the curved back  62  to rotate downward until the lower edge  102  engages the upper edge  104 . The tonneau cover  10  is at an angle “A” of about 23°. At this point, the gas or air cylinders  24  are disconnected from their mountings in the cargo bed sides  34 . The tonneau cover  10  is then raised further beyond the angle A. As the tonneau cover  10  is raised further, the top plate curved back  62  continues to rotate about the split pin  72  and engages the upper edge  104  of the mid plate curved back  58  causing the mid plate to also rotate about the split pin  72 . This rotates the mid plate  38  and the locking tongue  50 . The tonneau cover  10  is further raised until the locking tongue  50  is raised sufficiently to clear the locking channel  98  in the locking tab  90 . This is illustrated in  FIG. 8 . In this position the tonneau cover  10  is pulled back toward the tailgate  28  until the locking tongue  50  is at least over the leading end  92  of the locking tab  90  and is clear of the locking channel  98 . The tonneau cover can then be fully removed by sliding it off of the cargo bed  12 . 
     Thus there has been provided a hinge that allows for the easy installation and removal of a tonneau cover for pickup trucks that fully satisfies the objects and advantages set forth herein. While the invention has been described in conjunction with a specific embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations.