Patent Publication Number: US-6705880-B2

Title: Male plug protector for trailer wiring harness

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a Continuation-In-Part of Ser. No. 10/073,412, filed Feb. 13, 2002 now U.S. Pat. No. 6,638,083, which claims the benefit of U.S. Provisional Patent Application Serial No. 60/279,667, filed Mar. 30, 2001. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to electrical plug protectors. More particularly, the present invention relates to male plug protectors for trailer wiring harness connection plugs. 
     2. Description of Related Art 
     When disconnecting a trailer from a towing vehicle, it would be helpful to provide a device mounted on the trailer in which the male plug of the trailer may be stored when the trailer is not in use. The device should provide a relatively snug fit while protecting the electrical plug from exposure to the weather, etc. 
     U.S. Pat. No. 3,176,257, issued Mar. 30, 1965 describes a bracket for holding trailer plugs of tractor-trailer vehicles. The plug holder &#39;257 patent is designed to rotatably receive a specific type of plug, and the plug holder has no covering to keep out dust, etc. 
     U.S. Pat. No. 3,482,203, issued Dec. 2, 1969, to Whitright describes an electrical connector-storing device for trailers. This device has no cover for protection to keep out dust, etc. when not in use, and relies on a ring or bail to hold the male connector. The ring device requires a particular type of plug shape where it is attached to the wire conduit in order to maintain the plug in the hood or protector. 
     U.S. Pat. No. 4,017,136, issued Apr. 12, 1977 to Sasgen, describes a male plug holder for holding a plug for a locomotive control cable when not in use. The male plug holder is oriented in a forward position, thus allowing rain or other environmental hazards into the plug. The plug holder of the &#39;136 patent is designed for a particular plug for a train locomotive and would not be practical for vehicle-pulled trailer connectors. 
     U.S. Pat. No. 4,738,641, issued Apr. 19, 1988, to Eversol, Jr., describes a spring loaded trailer electrical connector protector device for protecting male trailer connectors when not in use. The &#39;641 device requires wings which fit into notches at the lower end of the device which is an uncommon feature on trailer connectors. 
     U.S. Pat. No. 4,770,644, issued Sep. 13, 1988, to Feder, describes a typical trailer plug connector of the type contemplated by the present invention and a receiving female connector having a hinged spring cover. 
     U.S. Pat. No. 5,380,209, issued Jan. 10, 1995, to Donvers, Jr. et al. describes a trailer connector housing which has an upward opening lid and side slots to receive electrical wires, and, a screw-on protector and casing for attachment to the vehicle. The trailer connector housing of the &#39;209 patent is subject to entrance of environmental rain or dust. 
     U.S. Pat. No. 5,630,728, issued May 20, 1997, to Watters, Jr., describes a plug holder for trailers or towing vehicles. The &#39;728 holder is vertically or horizontally mounted, allowing entrance of rain or mud, and is keyed to a particular connector. 
     U.S. Pat. No. 5,722,854, issued Mar. 3, 1998, to Geisler, describes a sleeve type trailer plug holder having an end cap for sealing the open end. The &#39;854 device requires a snug fit between the plug holder and the trailer plug. The end cap must be inserted to assure protection from the elements. The end cap is subject to accidental removal, allowing the elements to enter the plug holder. The user may also forget to fasten the end cap securely. 
     U.S. Pat. No. 5,800,188, issued Sep. 1, 1998, to Barber et al., describes a trailer tow inter-connector having a spring-loaded cover similar to that of the present invention. 
     None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. 
     SUMMARY OF THE INVENTION 
     The present invention is a vertically oriented male plug protector for a trailer wiring harness connection plug having a female type receptacle with a spring-biased hinged cover at its lower end. The upper end is closed. The device has a back plate with mounting holes for mounting to a trailer near the hitch end or on the hitch frame. When the trailer is not in use, the cover is pulled back and the male wiring harness plug is inserted into the female receptacle. In one embodiment the male plug end is retained in the protector by the spring action of the cover and a protrusion on the interior of the cover corresponding to a projection located on the male plug wall. To remove the plug, the user pulls back the cover and removes the plug. In another embodiment, the male plug end is retained in the protector by the spring action of the cover and a lower curved wall corresponding to the base of the male plug and having a centrally disposed opening for passage of the male plug electrical wiring harness closing over the male plug. The electrical wiring harness plug is retained within the protector to prevent environment damage from occurring to the plug&#39;s electrical connectors when the trailer is not in use. The protector has no electrical connections. 
     Accordingly, it is a principal object of the invention to provide a protector apparatus for safe storage of a male electrical plug for a trailer. 
     It is another object of the invention to provide a plug protector as above which mounts on the front wall or the hitch frame of a trailer. 
     It is a further object of the invention to provide a plug protector as above where the male plug is inserted upward into the protector and the protector completely encloses the upper portion of the plug. 
     Still another object of the invention is to provide a plug protector as above having a biased, hinged lower cover which may be pulled open to allow entry of the male plug, and then partially allowed to close by spring bias to retain the male plug within the plug protector. 
     Yet another object of the invention is to provide another embodiment of a plug protector where the male plug is inserted upward into the protector and a biased, hinged lower cover which may be pulled open to allow the entry of the male plug and then allowed to completely close around the plug to retain the male plug within the plug protector. 
     It is yet a further object of the invention to provide plug protectors as above having tabs on the spring biased cover which may be employed to release the male plug for withdrawal, and then released to allow the spring biased cover to closing over the lower portion of the plug receptacle to avoid entry of dirt, etc. 
     It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a male plug protector for trailer wiring harness according to the present invention with the lower lid removed. 
     FIG. 2 is a side view in elevation of the present invention shown with a male plug inserted therein. 
     FIG. 3 is a bottom rear view in perspective of the present invention with the lower cover closed. 
     FIG. 4 is a bottom rear view in perspective of the present invention, absent the lower lid. 
     FIG. 5 is a perspective view of the bottom lid of the present invention showing the axle and spring which forms a hinge with the receptacle portion of the plug protector. 
     FIG. 6 is an environmental perspective view of another embodiment of the plug protector of the present invention. 
     FIG. 7 is a section view taken along the line  7 — 7  of FIG.  6 . 
     FIG. 8 is a perspective view of the plug protector of FIG. 6 with the cover closed over the plug. 
     FIG. 9 is an exploded view of the plug protector of FIG.  6 . 
     FIG. 10A is a front elevation view of the plug protector of FIG. 6 with the cover in the closed position. 
     FIG. 10B is a front elevation view of the plug protector of FIG. 6 with the cover in the open position. 
     FIG. 11A is a rear elevation view of the plug protector of FIG. 6 with the cover in the closed position. 
     FIG. 11B is a rear elevation view of the plug protector of FIG. 6 with the cover in the open position. 
     FIG. 12A is a bottom view of the plug protector of FIG. 6 with the cover in the closed position. 
     FIG. 12B is a bottom view of the plug protector of FIG. 6 with the cover in the open position. 
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is a vertically oriented, male plug protector for a trailer wiring harness connection plug having a female type receptacle with a spring-biased hinged cover at its lower end. The upper end is closed. The device has a back plate with mounting holes for mounting to a trailer near the hitch end. When the trailer is not in use, the cover is pulled back and the male wiring harness plug is inserted. In one embodiment the male plug end is retained in the protector by the spring action of the cover and a protrusion on the interior of the cover corresponding to a projection located on the male plug wall. In another embodiment of the invention the male plug end is retained in the protector by the spring action of the cover and a lower curved wall corresponding to the base of the male plug closing over the male plug. To remove the plug, the user pulls back the cover and removes the plug. The electrical wiring harness plug is retained within the protector to prevent environment damage from occurring to the plug&#39;s electrical connectors when the trailer is not in use. The protector has no electrical connections. 
     Referring to FIGS. 1-4, various perspective views of plug protector  10  are shown wherein plug protector  10  comprises vertically oriented male plug receptacle  12 , having a spring biased, hinged lower cover  14  (see FIG.  2 ). Receptacle  12  has a vertically oriented back plate  16  having mounting holes  18  for mounting on a sidewall of a trailer, etc. Plug receptacle  12  has a top portion  20  acting as a closed, fixed upper wall for receptacle  12  and extending to said back plate  16  for additional support. 
     Receptacle back plate support walls  22  are vertically oriented and normal to said back plate  16  and extend from support wall back plate connections  24  to respective tangential intersections  28  on vertically oriented receptacle cylindrical portion  26  at the respective ends of a diameter parallel to said back plate  16 , said support walls  22  connecting along cylindrical portion  26  at support wall cylindrical intersections  28 . 
     Receptacle top portion  20  covers said cylindrical portion  26  and extends between support walls  22  and said back plate  16 , thus forming an inverted “U”-shaped support between said cylindrical portion  26  and said back plate  16 . Cylindrical portion  26  of receptacle  12  has a groove portion  30  extending vertically along cylindrical portion  26  at a location opposite back plate  16 . Receptacle lower plate  32  defines the lower end of cylindrical portion  26 , and comprises lower plate extended portion  33  extending outward from said cylindrical portion  26  and which supports lower plate hinge portion  34  having axle receiver  36  for connection with spring biased, hinged cover  14 . 
     Receptacle lower plate  32  includes lower plate plug receiving portion  38  opposite hinge portion  34  and includes lower plate under portion  39  (see FIG. 4) extending from the receptacle cylindrical portion  26  to back plate  16 , forming a boxlike structure with receptacle back plate support walls  22  and receptacle top portion  20 . Receptacle cylindrical portion  26  of lower plate  32  is cut away to form a semicircular portion extending from tangential intersections  28  to back plate  16 , thus forming under portion  39 . The lower plate plug receiving portion  38  of lower plate  32  serves as a lower extension of cylindrical portion  26  and forms lip  40  extending from bottom plate lower surface  41  at the lower opening inner cylindrical surface  42 . The outer surface plug receiving portion  38  is conically shaped in its semicircular portion, tapering inwardly from lower plate under portion  39  to lower surface  41  (see FIG.  4 ). 
     Referring particularly to FIGS. 2 and 3, there is shown a side view in elevation of the inventive plug protector  10  with a male plug inserted therein, and a bottom rear view in perspective of the present invention with the bottom cover closed, respectively. Male plug MP, having male plug key MPK, is shown inserted into receptacle cylindrical portion  26  along inner cylinder surface  42 , having receptacle key receiver groove  44 , formed within groove portion  30  and is sized and configured so as to receive male plug MP. Protrusion  56  protrudes from cover  14  (see FIG. 5) and is so configured as to interlock with male plug projection MPP, located at the base of key MPK, when male plug MP is inserted upward into receptacle  12  (see FIG.  2 ). Inner cylindrical surface  42  (see FIG. 4) and inner cylinder top surface  43  provide clearance for male plug MP. A lip  48  on hinged cover  14 , forms an overlapping seal with cylindrical portion lip  40  when cover  14  is in the closed position. 
     Referring, particularly, to FIG. 4, there is shown a bottom rear view of the plug holder  10  of the present invention without the hinged cover  14  and wherein receptacle cylindrical portion  26  features receptacle inner cylinder  42 , having receptacle key receiver groove  44 . Inner cylinder  42  is of such dimensions as to receive standard male electrical plug MP having a male plug key MPK and being useful for a trailer. Central support wall  60  is located parallel to back plate support walls  22  and extends between receptacle cylindrical portion  26 , receptacle top portion  20 , lower plate  29  and back plate  16 . For ease of construction, the portion of the back plate between support walls  22 , receptacle top portion  20  and lower plate  39  and receptacle cylindrical portion  26  may be deleted. 
     Referring to FIGS. 3 and 5, there are shown perspective views of the spring biased, hinged cover  14  of the present invention. Cover  14  is a generally flat plate having a plug receiver cover portion  50 , an extended portion  54  and a hinge portion  55  and having a lower surface  46  and an upper surface  47 , generally corresponding in shape to bottom plate lower surface  41 . 
     Plug receiver cover portion  50  is generally cylindrical, having an outer sidewall  52 . The cover upper surface  47  defines a lip  48  surrounding a recess within plug receiving cover portion  50  and extended portion  54  and shaped for receiving lip  40  of lower plate receiving portion  38 . The recess has inner end wall  62  at its base and is defined by hinged cover inner recess wall  64 . Inner end wall  62  supports centrally located hinged wall protrusion  56  protruding upward from inner end wall  62  and which is so configured as to interlock with male plug projection MPP when male plug MP is inserted into receptacle  12  (see FIG.  2 ). Axle  66  is fixedly mounted within axle receiver  36  of lower plate hinge portion  34  and for rotation within cover hinge portion  55 . Axle  66  is surrounded by hinge spring  68  and is so located and configured as to maintain a closing bias on hinged cover  14  in a known manner. Plug receiver cover portion outer sidewall  52  is conical in shape, tapering inwardly from cover upper surface  47  to lower cover outer wall  46 . Inner recess wall  64  may be conical in shape, corresponding to outer sidewall  52 . Pull tabs  58  are distributed around outer sidewall  52 , extending outward from lower cover lip  48 . 
     In operation, plug protector  10  is mounted in an appropriate place, such as a front wall of a trailer, by means of back plate  16  such that receptacle  12  may receive a standard male plug MP from below, i.e., receptacle cylindrical portion  26  is installed in a vertical orientation and spring biased, hinged cover  14  is hingedly attached at the base of the receptacle  12 . Hinged cover  14  is opened so as to rotate around the axle  66  by pulling on hinged wall pull tabs  58  against the force of spring  68  to a male plug insert and removal position. Male plug MP is inserted upwards within receptacle inner cylinder  42  and along receptacle key receiver groove  44  until male plug projection MPP passes hinged wall protrusion  56  of spring biased, hinged cover  14 . The bias from spring  68  allows projection  56  of cover  14  to close over male plug projection MPP to a male plug retention position, thus retaining male plug MP within the plug protector  10 . 
     When it is desired to remove male plug MP from plug protector  10 , spring biased, hinged cover  14  is pulled against the bias of spring  68  by means of pull tabs  58 , until protrusion  56  of cover  14  clears the male plug projection MPP of male plug MP at the male plug insert and removal position. The male plug MP may then be withdrawn for connection with the towing vehicle or other source of electricity. The spring  68  automatically closes cover  14  such that lower cover upper surface  47  closes against lower plate lower surface  41  and lip  48  of cover  14  closes over lip  40  of lower plate plug receiving portion  38  of receptacle  12 , thus sealing the protector against entry of dirt, etc. 
     Referring to FIGS. 6-12B there are shown views of another embodiment of the present invention for receiving another conventional trailer wiring plug wherein the contacts are a line and they are embedded in a generally linear plug LP of a wiring harness WH. The plug is typically rounded at its ends and at its neck where the wiring harness WH enters the plug. Although four lead wires and contacts are shown, the inventive plug receiver may accommodate similar plugs having more or fewer contacts and lead wires. The linear plug protector  100  is vertically disposed, being attached by screws S such as self tapping screws to a vertical surface such as hitch frame HF or a fifth wheel box (not shown) and includes a rectangular plug receiver  102  having a front wall  104 , side walls  106 , and a top wall  108  and being integral with a plug receiver mounting plate  110 , the bottom being open to receive plug LP. 
     Mounting plate  110  extends horizontally beyond sidewalls  106 , forming mounting plate extension portions  112  on each side of plug receiver  102 , each having at least one mounting bore  114  located therein for attaching the plug receiver  102  to hitch frame HF. As best seen in FIG. 7, top wall  108  slopes slightly forward to allow water to readily drain off the plug receiver. 
     Plug receiver  102  has a lower cover hinge housing  116  integral with and extending outward from the central portion of the lower end of front wall  104  and even with and sharing a lower end surface  160  (see FIGS.  7  and  12 B). Hinge housing  116  is generally rectangular in shape and has a horizontal upper wall  118 , a front wall  120 , and sidewalls  122  and provides for hinged connection with hinged lower cover  124 . Lower cover  124  has a cover portion  126  for covering the lower end of plug receiver  102  and a hinge extension portion  128  for attachment of cover  124  to cover hinge housing  116 . Hinge extension portion  128  is spring biased (see FIG. 7) relative to hinge housing  116  so as to maintain cover  126  in a closed position and has hinge grooves  130  to receive hinge housing outer hinge members  132  at each side thereof. A hinge pin  134  extends through and is secured by outer hinges  132  and extends through cover inner hinges  144  (see FIGS.  7  and  8 ). 
     Cover  126  has a cutout  136  in cover endwall  140  and extending inward along cover  126  for a distance adequate to receive wiring harness WH. Cover sidewalls  138  extend upward from cover end wall  140  to cover shoulders  141  which intersect with cover hinge extension portion  128 . The sidewalls  138 , end wall  140  and shoulders curve downward to the lower surface of cover portion  126  and the sidewalls of cover hinge extension portion  128  slope downward to the lower surface thereof. Cover tabs  142  extend outward from each sidewall  138  to assist in opening cover  126  against the spring biased hinge for inserting and removing linear plug LP. 
     As seen in FIGS. 9 and 11B spring  145  extends around hinge pin  134  between cover inner hinges  144  and is secured at one end and bears against a groove (not shown) in the end of hinge housing lower wall  148  of cover hinge extension portion  128  so as to exert closing force to cover  124 , to keep it closed against plug receiver lower surface  160 . The user may open the plug receiver  102  by pulling downward on tabs  142  to insert or remove plug LP. As seen in FIG. 7, hinge housing  116  has an inner upright wall  146  and a lower wall extending outward from inner wall  146 . As seen in FIG. 9, hinge pin  134  extends through outer hinge bores  150  and cover hinge bores  152 . 
     As best seen in FIGS. 7 and 11B, cover portion  126  has a hollow inner side shaped to receive the plug LP defined by inner peripheral wall surface  156  surrounding inner cover surface  158  and has an upper wall surface  161  which closes against plug receiver lower surface  160 . Partial rims  139  extend upward from cover inner peripheral wall  156  at side walls  138 , end walls  140 , and shoulders  141  and extend upward along the inner walls of plug receiver  102  to form a dust barrier when cover  126  is in the closed position. As seen in the bottom view, FIG. 12B, plug receiver  102  has an upper wall surface  162  and a forward curving hinge housing inner wall  164 . 
     As best seen in FIGS. 11A and 11B, mounting plate  110  preferably has reinforcing ridges R extending rearward from rear surface  154  surrounding the rear of the mounting plate and mounting bores  114 , and crossing the rear surface of the mounting plate for reinforcement while saving material and weight. 
     In operation, cover  126  is opened downward by pulling downward on tabs  142  to the open position against the bias of spring  145 . The linear plug LP, removed from the pulling vehicle socket, is pushed upward into the plug receiver  102  with the connectors pointing upwards. The spring biased cover is then allowed to close over the plug with the wiring harness WH extending downward through cover cutout  136 . The plug and electrical connectors are thus protected from dust and the elements when not in use. To remove the plug for use, the cover is pulled downward with tabs  142  and the plug removed, the spring biased cover, upon plug removal, closing upward against plug receiver  102  thus keeping dirt or other matter from entering the unused plug protector. 
     It is clear from the forgoing discussion that the 4/5 way plug protector can be used on both the tow vehicle and/or the trailer, and thus will accommodate both the male and female versions of the 4/5 way plug. 
     It is to be understood that the present invention is not limited to the sole embodiments described above, but encompasses any and all embodiments within the scope of the following claims.