Patent Publication Number: US-6701761-B1

Title: Lock system for vehicles and the like

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to key locks, and in particular to a lock system for vehicles and the like. 
     Key locks for vehicles and the like are generally well known in the art. Recreational vehicles typically have a number of key locks to control access to various areas of the vehicle, such as access doors to the vehicle interior, closures for storage compartments, and the like. While such locks are often configured so that a single key fits all locks, a problem exists, particularly at dealer lots, showrooms and the like, in managing and tracking the numerous keys for the vehicles being offered for sale. A salesman will typically require access to all lockable areas of a vehicle to properly show the vehicle to a prospective buyer. Also, customers normally want to be shown numerous vehicles before making a final selection, such that the efficient and accurate management of the numerous vehicle keys involved presents a significant challenge. 
     While special master keys are sometimes used to access all areas of a number of different vehicles to facilitate showing and/or demonstrating the vehicles to prospective purchasers, the locks must be re-keyed when the vehicle is sold to provide the buyer with adequate security. Consequently, a lock system that provides customers and sales personnel with easy access to the lockable areas of a vehicle, yet can be readily converted to personalize the locks after the sale of the vehicle, would be advantageous and represent a significant advancement in the vehicle lock art. 
     SUMMARY OF THE INVENTION 
     One aspect of the present invention is a lock system for vehicles and the like of the type having at least one closure. A lock housing is mounted adjacent the closure, and includes a lock barrel with an axial tumbler groove, a positioner shoulder adjacent an outer portion of the barrel and a keeper shoulder adjacent an inner portion of the barrel. A lock plug is closely received in the barrel for rotation between locked and unlocked positions, and includes a keyway and outwardly biased, radially shifting tumblers. A control key is inserted into the keyway to retract all of the tumblers except a positioner tumbler that engages the positioner shoulder to locate the lock plug in a first axial position in the barrel. When the control key is removed, an outer keeper tumbler is biased outwardly for abutting contact with the keeper shoulder. A dealer key is inserted into the keyway to retract all of the tumblers except the positioner and outer keeper tumblers to permit rotation of the plug between the locked and unlocked positions. A customer key is inserted into the keyway to retract all of the tumblers except the outer keeper tumbler, and shift the plug axially into a second axial position in the barrel, wherein an inner keeper tumbler is biased outwardly for abutting contact with the keeper shoulder, and the positioner tumbler is shifted into the tumbler groove to prevent rotation of the plug by the dealer key to provide customer security. 
     Another aspect of the present invention is to provide a lock system for vehicles and the like of the type having at least one closure. A lock housing is mounted adjacent the closure, and includes a lock barrel with an axial tumbler groove, a positioner shoulder adjacent an outer portion of the barrel and a keeper shoulder adjacent an inner portion of the barrel. A lock plug is closely received in the barrel for rotation between locked and unlocked positions, and includes a keyway and outwardly biased, radially shifting tumblers. A first key is inserted into the keyway to retract all of the tumblers except a positioner tumbler that engages the positioner shoulder to locate the lock plug in a first axial position in the barrel. When the first key is removed, an outer keeper tumbler is spring biased outwardly for abutting contact with the keeper shoulder. A second key is inserted into the keyway to retract all of the tumblers except the positioner and outer keeper tumblers to permit rotation of the plug between the locked and unlocked positions. A third key is inserted into the keyway to retract all of the tumblers except the outer keeper tumbler, and shift the plug axially into a second axial position in the barrel, wherein an inner keeper tumbler is biased outwardly for abutting contact with the keeper shoulder, and the positioner tumbler is shifted into the tumbler groove to prevent rotation of the plug by the dealer key to provide customer security. 
     The present invention comprises a lock system that provides customers and sales personnel with easy access to the lockable areas of numerous vehicles, yet can be readily converted to personalize the locks of a specific vehicle after it is sold to provide the buyer with security. The lock system is quite durable, has reduced manufacturing costs, and an uncomplicated design. Furthermore, the invention is efficient in use, capable of a long operating life, and particularly well adapted for the proposed used. 
    
    
     These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims and appended drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a vehicle incorporating a lock system embodying the present invention. 
     FIG. 2 is a front elevational view of a latch assembly, which incorporates the lock system, and is shown installed in an access door of the vehicle. 
     FIG. 3 is a vertical cross-sectional view of a striker plate portion of the latch assembly. 
     FIG. 4 is a front elevational view of the striker plate. 
     FIG. 5 is a front elevational view of a housing portion of the latch assembly. 
     FIG. 6 is a horizontal cross-sectional view of the housing shown in FIG.  5 . 
     FIG. 7 is a top plan view of a paddle handle portion of the latch assembly. 
     FIG. 8 is a front elevational view of the paddle handle. 
     FIG. 9 is an enlarged, front elevational view of a barrel portion of the lock system. 
     FIG. 10 is an enlarged, cross-sectional view of the barrel. 
     FIG. 11 is an enlarged, rear elevational view of the barrel. 
     FIG. 12 is a rear elevational view of the latch assembly, wherein selected portions thereof have been removed to reveal internal detail. 
     FIG. 13 is a front elevational view of a latch bolt portion of the latch assembly. 
     FIG. 14 is a side elevational view of the latch bolt. 
     FIG. 15 is a rear elevational view of a deadbolt portion of the latch assembly. 
     FIG. 16 is a top plan view of the deadbolt. 
     FIG. 17 is a rear elevational view of the latch assembly, wherein the latch bolt is shown in an extended position, and the deadbolt is shown in a retracted position. 
     FIG. 17A is a front elevational view of the latch assembly in the position shown in FIG.  17 . 
     FIG. 18 is a rear elevational view of the latch assembly, wherein the latch bolt is shown in a retracted position, and the deadbolt is shown in an extended position. 
     FIG. 18A is a front elevational view of the latch assembly in the position shown in FIG.  18 . 
     FIG. 19 is a top plan view of a back plate portion of the latch assembly. 
     FIG. 20 is a front elevational view of the back plate. 
     FIG. 21 is a rear elevational view of the back plate. 
     FIG. 22 is a front elevational view of a lock plug portion of the lock system. 
     FIG. 23 is a side elevational view of the lock plug, wherein a portion thereof has been broken away to reveal internal construction. 
     FIG. 24 is a rear elevational view of the lock plug. 
     FIG. 25 is a top plan view of the lock plug. 
     FIG. 26 is a bottom plan view of the lock plug. 
     FIG. 27 is a side elevational view of a control key portion of the lock system. 
     FIG. 28 is a side elevational view of the control key shown inserted into the lock plug. 
     FIG. 29 is a side elevational view of a dealer key portion of the lock system. 
     FIG. 30 is a side elevational view of the dealer key shown inserted into the lock plug. 
     FIG. 31 is a side elevational view of a customer key portion of the lock system. 
     FIG. 32 is a side elevational view of the customer key shown inserted into the lock plug. 
     FIG. 33 is a top plan view of a housing portion of the lock plug. 
     FIG. 34 is a cross-sectional view of the lock plug housing. 
     FIG. 35 is a front elevational view of a positioner tumbler portion of the lock plug. 
     FIG. 36 is a side elevational view of the positioner tumbler. 
     FIG. 37 is a front elevational view of a first lock tumbler portion of the lock plug. 
     FIG. 38 is a side elevational view of the first lock tumbler. 
     FIG. 39 is a front elevational view of a second lock tumbler. 
     FIG. 40 is a front elevational view of a third lock tumbler. 
     FIG. 41 is a front elevational view of a fourth lock tumbler. 
     FIG. 42 is a front elevational view of an inner keeper tumbler portion of the lock plug. 
     FIG. 43 is a side elevational view of the inner keeper tumbler. 
     FIG. 44 is a front elevational view of an outer keeper tumbler portion of the lock plug. 
     FIG. 45 is a side elevational view of the outer keeper tumbler. 
     FIG. 46 is a side elevational view of the lock plug with the control key inserted therein, shown prior to assembly in the lock barrel. 
     FIG. 47 is a side elevational view of the lock plug with the control key inserted therein, shown assembled in the lock barrel. 
     FIG. 47A is an end elevational view of the lock plug and lock barrel assembly shown in FIG.  47 . 
     FIG. 48 is a side elevational view of the lock plug shown assembled in the lock barrel with the control key removed. 
     FIG. 48A is an end elevational view of the lock plug and lock barrel assembly shown in FIG.  48 . 
     FIG. 49 is a side elevational view of the lock plug assembled in the lock barrel with the dealer key inserted into the lock plug, wherein the lock plug is shown in a first axial position within the lock barrel. 
     FIG. 50 is a side elevational view of the lock plug assembly in the lock barrel with the customer key inserted into the lock plug, wherein the lock plug is shown in a first axial position within the lock barrel. 
     FIG. 51 is a side elevational view of the lock plug assembled in the lock barrel, with the customer key inserted into the lock plug, wherein the lock plug is shown in a second axial position within the lock barrel. 
     FIG. 51A is an end elevational view of the lock plug and lock barrel shown in FIG.  51 . 
     FIG. 52 is a side elevational view of the lock plug in the second axial position in the lock barrel, wherein the customer key has been removed. 
     FIG. 53 is a side elevational view of the lock plug in the second axial position in the lock barrel, wherein the dealer key has been inserted into the lock plug. 
     FIG. 54 is a side elevational view of the lock plug in the second axial position in the lock barrel, shown with the control key installed in the lock plug. 
     FIG. 55 is a front elevational view of another embodiment of the present invention, wherein the lock system is installed in a latch assembly for a vehicle storage compartment, with the latch assembly shown in a latched position. 
     FIG. 56 is a vertical cross-sectional view of the latch assembly shown in FIG. 55, wherein the lock plug with the control key inserted therein has been removed. 
     FIG. 57 is a front elevational view of the latch assembly of FIG. 55, shown in an unlatched position. 
     FIG. 58 is a vertical cross-sectional view of the latch assembly of FIG. 55, shown in the unlatched position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For purposes of description herein, the terms “upper”, “lower”, “right”, “left”, “rear”, “front”, “vertical”, “horizontal” and derivatives thereof shall relate to the invention as oriented in FIGS. 1 and 2. However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and process illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
     The reference numeral  1  (FIGS. 1 and 2) generally designates a lock system embodying the present invention, which is particularly adapted for use in conjunction with vehicles and the like, such as the illustrated recreational vehicle  2  of the type having at least one entry closure or door  3 . A lock housing  4  is mounted adjacent door  3 , and includes a lock barrel  5  (FIGS. 5-11) with an axially extending tumbler groove  6 , a positioner shoulder  7  disposed adjacent an outer portion of barrel  5 , and a keeper shoulder  8  disposed adjacent an inner portion of barrel  5 . A lock plug  9  (FIGS. 22-32) is closely received in barrel  5  for rotation between locked and unlocked positions, and includes a keyway  10  and outwardly biased, radially shifting tumblers  11 . A control key  12  is inserted into the keyway  10  of lock plug  9  to retract all of the tumblers  11  except a positioner tumbler  13  that engages the positioner shoulder  7  to locate lock plug  9  in a first axial position in barrel  5 , as shown in FIG.  47 . When control key  12  is removed from keyway  10 , as shown in FIG. 48, an outer keeper tumbler  14  is biased outwardly for abutting contact with the keeper shoulder  8 . A dealer key  15  is inserted into the keyway  10  of lock plug  9 , as shown in FIG. 49, to retract all of the tumblers  11  except positioner tumbler  13  and outer keeper tumbler  14  to permit rotation of lock plug  9  between the locked and unlocked positions. A customer key  16  is inserted into the keyway  10  of lock plug  9 , as shown in FIG. 50, to retract all of the tumblers  11  except outer keeper tumbler  14 . Lock plug  9  is shifted axially into a second axial position in lock barrel  5 , as shown in FIG. 51, wherein an inner keeper tumbler  17  is biased outwardly for abutting contact with the keeper shoulder  8 , and the positioner tumbler  13  is shifted into tumbler groove  6  to prevent rotation of lock plug  9  by the dealer key  15 , so as to provide customer security. 
     The illustrated recreational vehicle  2  is in the nature of a fifth wheel trailer having a body  22  supported on ground-engaging wheels  23 . Trailer body  22  has at least one entry closure or door  3  to access the interior of trailer body  22 . Furthermore, the illustrated trailer  2  includes a plurality of exterior storage compartments  24 , each of which includes a closure or door  25 , which preferably also incorporates a lock system  1  embodying the present invention. Other than lock system  1 , the illustrated trailer  2  has a conventional construction, with windows  26 , a fold up awning  27 , and retractable support props  28 . As will be apparent to those skilled in the art, lock system  1  may be used in a wide variety of different applications and environments. 
     In the example illustrated in FIGS. 2-21, lock system  1  is incorporated into a paddle latch assembly  30 , wherein the lock housing portion  4  thereof is shown installed in the entry door  3  of trailer  2 . Paddle latch assembly  30  includes a striker plate  31  (FIGS. 2-4) that is mounted in a frame  32  surrounding the opening in which entry door  3  is mounted. Striker plate  31  has a substantially rectangular front elevational configuration, and includes a central window  33  to selectively receive therein lock and latch portions of paddle latch assembly  30 , as described in greater detail hereinafter. Striker plate  31  includes a pair of mounting flanges  34  which extend outwardly from the top and bottom of striker plate  31 , and incorporates fastener apertures  35  to facilitate mounting striker plate  31  to the doorframe  32  in a horizontally aligned relationship with lock housing  4 . Striker plate  31  also includes a pair of side flanges  36 , which are received in a mating recess in doorframe  32 . 
     With reference to FIGS. 5-8, lock housing  4  has a generally rectangular front elevational configuration with rounded corners, and includes a substantially flat marginal portion  38  and a centrally disposed recess  39 . In the illustrated example, lock barrel  5  is positioned in a lower area of marginal portion  38 , adjacent one corner of recess  39 . Lock housing  4  includes a laterally protruding portion  40 , which as best shown in FIGS. 12-18A, includes on the interior side thereof, a latch bolt slide  41  and a deadbolt slide  42 , which are disposed in a mutually parallel relationship. The recess portion  39  (FIGS. 5-8) of lock housing  4  includes sidewalls  43  with a pair of vertically oriented apertures  43 ′ therein, which serve to pivotally mount a paddle handle  44  within recess  39 . As shown in FIG. 7, paddle handle  44  has a generally L-shaped top plan configuration, and includes an actuator tab  45 , which extends through a window  46  in the bottom wall  47  of recess  39 . Paddle handle  44  also has a generally flat front plate portion  47 ′ shaped to fit within housing recess  39 , with a finger recess formed on the interior surface thereof. 
     As best illustrated in FIGS. 12-18, paddle latch assembly  30  includes a latch bolt  48  that is slidably mounted within latch bolt slide  41  for lateral translation between the extended position shown in FIG. 17, and the retracted position shown in FIG.  18 . Latch bolt  48  includes a central window  49  which receives therein the tab  45  of paddle handle  44 , such that when paddle handle  44  is rotated, latch bolt  48  shifts longitudinally within latch bolt slide  41 . The illustrated paddle latch assembly  30  also includes a deadbolt  50  which is closely received in deadbolt slide  42  for longitudinal shifting between the retracted position shown in FIG. 17, and the extended position shown in FIG.  18 . Deadbolt  50  includes a link aperture  51  through the interior end thereof. Deadbolt  50  is shifted longitudinally between its retracted and extended positions by rotation of lock plug  9  relative to lock housing  4  in the following manner. A bell crank  52  (FIGS. 17 and 18) is pivotally supported on lock housing  4  adjacent the inner portion of lock barrel  5 . A first link  53  has one end thereof pivotally mounted to bell crank  52 . A connector arm  54  is pivotally mounted adjacent its lower end to the rear portion of lock housing  4  by a pin  55 , and includes a pair of link apertures  56  and  57  disposed adjacent its upper end, opposite pin  55 . First link  53  has its opposite end pivotally mounted in aperture  56  of connector arm  54 . A second link  58  has one end pivotally mounted in link aperture  57  on connector arm  54 , and its opposite end pivotally connected in the link aperture  51  of deadbolt  50 . To shift deadbolt  50  from the fully retracted, unlocked position shown in FIG. 17, lock plug  9  is rotated relative to lock barrel  5 , as described in greater detail below, thereby rotating bell crank  52 , which in turn rotates connector arm  54  through first link  53 , which in turn shifts second link  58  laterally to longitudinally move deadbolt  50  to the fully extended, locked position shown in FIG.  18 . In the fully locked position shown in FIG. 18, deadbolt  50  extends through the central window  33  in striker plate  31 , thereby positively preventing entry door  3  from being opened. To open entry door  3 , a preselected one of the keys  12 ,  15  and  16  is inserted into the keyway  10  of lock plug  9  to retract selected tumblers  11  to permit lock plug  9  to be rotated back to the unlocked position, as discussed below, which shifts deadbolt  50  back to the unlocked position shown in FIG.  17 . Rotation of paddle handle  44  in the manner shown in FIG. 18A retracts latch bolt  48  from the window  33  in striker plate  31 , to permit entry door  3  to be opened. 
     As best illustrated in FIGS. 19-21, paddle latch assembly  30  includes a back plate  60 , which is attached to and encloses the interior side of lock housing  4 . Back plate  60  includes a pivotally mounted interior handle  61 , having an inwardly protruding tab  62  received in the window  49  of latch bolt  48 , such that door  25  can be opened from the interior of the vehicle  2 . Back plate  60  also includes a manual deadbolt actuator  63  rotatably mounted thereon. Deadbolt actuator  63  is manually rotated from within the interior of vehicle  2  to shift deadbolt  50  between the locked and unlocked positions. 
     The illustrated lock barrel  5  (FIGS. 9-11) is integrally formed in lock housing  4 , and includes a generally circular interior surface  65  which is formed to define tumbler groove  6 , positioner shoulder  7 , and keeper shoulder  8 . The outermost portion of lock barrel  5  includes a rounded lip  66  which protrudes outwardly from the exterior surface of lock housing  4  and terminates at an outer end  67  of lock barrel  5 . A collar shoulder  68  is positioned axially inwardly from outer end  67 , and protrudes radially inwardly toward the center of lock barrel  5  a predetermined distance. Collar shoulder  68  defines the base of an associated collar recess  68 ′, which extends from outer collar end  67  to collar shoulder  68 . Positioner shoulder  7  is disposed axially inwardly from collar shoulder  68 , and also protrudes radially inwardly toward the center of lock barrel  5  a distance similar to that of collar shoulder  68 . The inner portion of lock barrel  5  includes a circular recess  69  which defines keeper shoulder  8 , and terminates at the inner end  70  of lock barrel  5 . Lock barrel  5  also includes a base shoulder  72  which is disposed a predetermined distance axially outwardly from keeper shoulder  8 , and is oriented substantially parallel with keeper shoulder  8 , as well as positioner shoulder  7  and collar shoulder  68 . 
     In the illustrated example, tumbler groove  6  (FIGS. 9-11) extends along the interior surface  65  of lock barrel  5  from positioner shoulder  7  to base shoulder  72 . Tumbler groove  6  has radially inclined sidewalls  73  and  74 , and an arcuate outer wall  75  disposed concentric with lock barrel  5 . As viewed in FIG. 5, tumbler groove  6  is positioned vertically upwardly in a substantially 12 o&#39;clock position on lock barrel  5 . The illustrated lock barrel  5  includes three additional grooves  76 - 78  which are disposed at 90 degree intervals from tumbler groove  6  and are positioned respectively at 3 o&#39;clock, 6 o&#39;clock and 9 o&#39;clock positions on lock barrel  5 . Grooves  76 - 78  have a front elevational configuration that is substantially identical with that of tumbler groove  6 . Grooves  76  and  78  extend from positioner shoulder  7  to base shoulder  72  in a manner similar to tumbler groove  6 , while groove  77  extends from collar shoulder  68  to base shoulder  72 . As best illustrated in FIG. 11, keeper shoulder  8  includes a radially extending locator keyway  79  that is axially aligned with groove  77  and serves to locate lock plug  9  in lock barrel  5  in the manner described in greater detail hereinafter. 
     With reference to FIGS. 22-32, the illustrated lock plug  9  has a generally cylindrical shape that is sized for close reception in lock barrel  5 , and rotates axially therein between the locked position (FIG. 18A) and the unlocked position (FIG.  17 A). As described in greater detail below, the illustrated lock plug  9  is configured to be bodily removed from lock barrel  5  to facilitate repair, re-keying and/or replacement. Lock barrel  5  has a radially protruding outer collar  88  that is sized to be closely received within the collar recess  68 ′ of lock barrel  5 . Outer collar  88  has a substantially circular front elevational configuration, with keyway  10  located centrally therein. Lock plug  9  also includes a body portion  89  (FIGS. 33 and 34) with a plurality of radially extending, mutually parallel slots  90 - 95  that are configured to slidingly mount tumblers  11  therein. As best shown in FIGS. 22-24, keyway  10  extends longitudinally or axially all the way through lock plug  9 , and communicates with each of the radially extending slots  90 - 95  to shift tumblers  11 . Slots  90 - 94  (FIG. 33) are substantially similar in shape, and have a generally rectangular plan configuration, with an ovate spring retaining aperture  96  positioned along one side thereof. Slot  95  is substantially wider than slots  90 - 94 , and includes two spring receiving apertures  96  disposed along opposite sides thereof in an axially staggered relationship for purposes to be described in greater detail hereinafter. The interior end  97  of lock plug  9  includes a pair of axially protruding pawls  98  positioned on opposite sides of keyway  10 . Pawls  98  are received in mating recesses in bell crank  52 , and serve to rotational connect lock plug  9  and bell crank  52 . As best illustrated in FIG. 23, seven longitudinally compressible coil springs  99  are mounted in spring retaining apertures  96 , and serve to bias tumblers  11  radially outwardly, as described in greater detail below. 
     With reference to FIGS. 35-45, tumblers  11  are received within the slots  90 - 95  of lock plug  9 , and are shifted axially by insertion of keys  12 ,  15  and  16  to control the operation of lock system  1 . In the illustrated example, each of the tumblers  11  is a wafer-type tumbler that is biased radially outwardly. Positioner tumbler  13  (FIGS. 35 and 36) has a generally rectangular front elevational configuration with an open base, and includes opposite side faces  105  and  106  disposed in a mutually parallel relationship. Positioner tumbler  13  includes two opposite leg portions  107  and  108 , and an arcuately-shaped top portion  109  interconnecting leg portions  107  and  108 . Top portion  109  includes radially oriented side edges  110  and  111 , and an arcuate top edge  112  which are shaped to be closely received within tumbler groove  6 . Leg portion  107  includes an outwardly protruding tab  113 , which extends into spring aperture  96  to engage the upper end of an associated spring  99 . The opposite leg portion  108  of positioner tumbler  13  includes a laterally extending detent  114  to selectively locate positioner tumbler  13  within slot  90 . 
     The illustrated lock plug  9  includes four key tumblers  120 - 123 , which have a substantially similar construction, and are sized to be slidably mounted in slots  91 - 94  of lock plug  9 . Each of the key tumblers  120 - 123  has a substantially rectangular front elevational configuration with a closed bottom  124 , opposite legs or side portions  125  and  126 , and an arcuate top portion  127 . The bottom portion  124  of key tumblers  120 - 123  has an arcuately-shaped end edge  128  that mates with the shape of groove  77  in lock barrel  5 . The top portion  127  of key tumblers  120 - 123  is substantially identical to the top portion  109  of positioner tumbler  13 , and includes radially extending side edges  129  and  130  and an arcuate top edge  131  which mate with tumbler groove  6 . Like positioner tumbler  13 , each of the key tumblers  120 - 123  includes a tab  132  extending laterally from side portion  125  and protruding into an adjacent one of the spring apertures  96  to engage the upper end of an associated spring  99 , and a detent  133  extending from the opposite side portion  126  to selectively locate the key tumblers  120 - 123  in lock plug  9 . Each of the key tumblers  120 - 123  also includes a central window  134 , which is axially aligned with keyway  10  to receive keys  12 ,  15  and  16  therethrough. Each of the windows  134  has a substantially rectangular plan configuration, and includes a stepped bottom edge  135  which engages bits on keys  12 ,  15  and  16  to laterally or radially shift tumblers  11 . The bottom edges  135  of key tumblers  120 - 123  are shaped slightly differently to engage specific bits of the various keys, and thereby provide a wide range of key combinations to improve security. 
     The keeper tumblers  14  and  17  (FIGS. 42-45) are somewhat similar to key tumblers  120 - 123 , except each has an enlarged head or top portion  140  and key-shaped bottom portion  141 , which are interconnected by opposite legs or side portions  142  and  143 . Keeper tumblers  14  and  17  have flat, mutually parallel faces  144  and  145 , and are shaped to be received in a side-by-side relationship within slot  95  of lock plug  9 . The top portion  140  of each of the keeper tumblers  14  and  17  has a generally arcuate outer edge  146  which extends laterally to create a tab  147  that protrudes into an associated one of the spring apertures  96  and engages the top edge of an associated spring  99  to bias the same radially outwardly. The opposite side portion  143  of each of the keeper tumblers  14  and  17  includes a laterally extending detent  148  which serves to selectively locate the keeper tumblers  14  and  17  within lock plug  9 . Each of the keeper tumblers  14  and  17  has a central window  149  having a generally rectangular plan shape, which is axially aligned with keyway  10  and is designed to receive keys  12 ,  15  and  16  therethrough. The bottom edge  150  of each keeper tumbler window  149  is flat, unlike the stepped bottom edges  135  of key tumblers  120 - 123 . The bottom portion  141  of each of the keeper tumblers  14  and  17  includes a radially protruding bottom edge  151  having a generally rectangular plan shape that is designed to be closely received within groove  77  of lock barrel  5 . As best illustrated in FIGS. 42-45, outer keeper tumbler  14  has an overall height or length that is slightly greater than that of inner keeper tumbler  17  for purposes to be described in greater detail hereinafter. 
     Lock plug  9  is assembled by first installing coil springs  99  in each of the seven spring retaining apertures  96  in the body portion  89  of lock plug  9 . Positioner tumbler  13  is installed in slot  90 , so that tab  113  engages the upper end of the associated coil spring  99  to bias the same radially outwardly. Tab  113  engages an adjacent surface in slot  90  to limit the lateral or radial travel of positioner tumbler  13 . Key tumblers  120 - 123  are similarly installed in slots  91 - 94  of lock plug  9 . The tabs  132  of key tumblers  120 - 123  engage the upper ends of associated springs  99 , and detents  133  serve to limit the lateral or radial shifting of key tumblers  120 - 123  in lock plug  9 . Outer keeper tumbler  14  is installed in slot  95  at the interiormost portion thereof, while inner keeper tumbler  17  is installed next to outer keeper tumbler  14  in the interiormost portion of slot  95 , such that the same assume a side-by-side relationship. The tab portions  147  of keeper tumblers  14  and  17  engage the upper ends of associated springs  99  to bias the keeper tumblers radially outwardly, while detents  148  serve to limit this axial shifting. 
     With reference to FIG. 27, control key  12  has a generally conventional construction, including a generally ovate head portion  160  adapted for grasping, and a longitudinally extending shank portion  161  configured to be closely received within keyway  10 . The shank portion  161  of control key  12  includes a plurality of bits  162  on opposite sides thereof, which are adapted to engage tumblers  11  and shift the same radially inwardly to control actuation of lock system  1 . In the illustrated example, shank portion  161  includes axially extending ribs  163  to improve security. The length of shank portion  161  of control key  12  is sufficient to extend all of the way through keyway  10 , and thereby selectively engage each of the tumblers  11 , including both keeper tumblers  14  and  17 . Control key  12  is particularly adapted for use by factory and/or service personnel to install, remove, repair and/or re-key lock plug  9 , as explained in greater detail below. 
     With reference to FIG. 29, dealer key  15  is somewhat similar to control key  12  insofar as it includes a generally ovate head portion  167  adapted for grasping, and a longitudinally extending shank portion  168  that is configured for close reception within keyway  10 . The shank portion  168  of dealer key  15  also includes a plurality of bits  169  on opposite sides thereof to selectively shift tumblers  11 . Shank portion  168  also includes axially extending ribs  170 , which are configured similar to the ribs  163  on control key  12 , and mate with the same of keyway  10 . The shank portion  168  of dealer key  15  is shorter than the shank portion  161  of control key  12 , and is received in keyway  10  a distance only sufficient to engage key tumblers  120 - 123  and not keeper tumblers  14  and  17 , as described in greater detail hereinafter. Dealer key  15  is particularly adapted for use by salespersons and the like, to open the lockable areas of the associated vehicle to show and/or demonstrate the same to a prospective purchaser. 
     With reference to FIG. 31, customer key  16  is somewhat similar to control key  12  and dealer key  15 , insofar as it includes a generally ovate head portion  174  adapted for grasping, and a longitudinally extending shank portion  175  configured to be closely received within keyway  10 . The shank portion  175  of customer key  16  also includes a plurality of bits  176  on opposite sides thereof which shift tumblers  11  to control operation of lock system  1 . The illustrated customer key  16  also includes axially extending ribs  177 , which are similar to the ribs  163  and  170  on control key  12  and dealer key  15  respectively, to mate with the shape of keyway  10  and improve lock security. The shank portion  175  of customer key  16  is shorter than the shank portion  161  of control key  12 , and extends into keyway  10  a distance which is only sufficient to engage positioner tumbler  13  and key tumblers  120 - 123 , as described in greater detail hereinafter. Customer key  16  is designed to be used by the ultimate purchaser of vehicle  2 . 
     With reference to FIGS. 46-54, the illustrated lock system  1  operates in the following manner. To install lock plug  9  in lock barrel  5 , control key  12  is inserted into keyway  10 . The bits  162  on control key  12  retract all of the key tumblers  120 - 123  and both of the keeper tumblers  14  and  17 , but leave the positioner tumbler  13  extended. The retraction of keeper tumblers  14  and  17  causes the key-shaped bottom edges  151  thereof to protrude downwardly or outwardly from lock barrel  5 , as shown in FIG.  46 . With control key  12  fully inserted into lock plug  9 , lock plug  9  is telescoped into lock barrel  5 , with the key portions  141  of keeper tumblers  14  and  17  being received within groove  77  of lock barrel  5 , as shown in FIG. 47A, to rotationally position lock plug  9 , such that key tumblers  120 - 123  are aligned with tumbler groove  6 . Lock plug  9  is inserted into lock barrel  5  until positioner tumbler  13  abuttingly engages positioner shoulder  7 , as shown in FIG.  47 . Control key  12  is then removed from keyway  10 , such that outer keeper tumbler  14  is spring biased radially outwardly for abutting engagement with keeper shoulder  8 , as shown in FIGS. 48 and 48A. The abutting contact between positioner tumbler  13  and positioner shoulder  7 , as well as outer keeper tumbler  14  and keeper shoulder  8 , positively positions lock plug  9  in a first axial position within lock barrel  5 . The first axial position of lock plug  9  is shown in FIGS. 47-50. The removal of control key  12  from keyway  10  also causes key tumblers  120 - 123  to be spring biased outwardly into tumbler groove  6 , thereby rotationally locking lock plug  9  in lock barrel  5 , and thereby retaining deadbolt  50  in its fully extended locked position. As best illustrated in FIG. 48, inner keeper tumbler  17  is retained in a retracted position by abutting contact with the edge  80  of base shoulder  72 . 
     With reference to FIG. 49, after lock plug  9  has been installed in lock barrel  5 , as outlined above, the lock system  1  may be unlocked by dealer personnel, salesmen or the like through the use of dealer key  15 . The bits  169  of dealer key  15  are configured to mate with key tumblers  120 - 123 , so that the insertion of the shank portion  168  of dealer key  15  into keyway  10 , as shown in FIG. 49, retracts all of the key tumblers  120 - 123 , but leaves the positioner tumbler  13  and the outer keeper tumbler  14  fully extended. Consequently, with dealer key  15  inserted into keyway  10 , lock plug  9  can be rotated from the locked position (FIGS. 18 and 18A) to the unlocked position (FIGS. 17 and 17A) to gain entrance to the interior of vehicle  2 , or to access a locked storage compartment, or other similar vehicle area. Positioner tumbler  13  and outer keeper tumbler  14  positively retain lock plug  9  in its first axial position (FIGS. 47-50) within lock barrel  5 , yet permit selective rotation of lock plug  9  between the locked and unlocked positions. Dealer key  15  operates similar to a master key system, wherein all of the locks can be operated with a single key, even though the lock plugs  9  may have different key codes. This feature permits the vehicle dealer to use one key to unlock or lock every lock on his lot or show area to minimize the management and/or tracking of numerous keys. 
     After vehicle  2  has been sold to a specific buyer, the purchaser is given a customer key  16  to operate lock system  1 . As shown in FIG. 50, the bits  176  on customer key  16  are configured to retract not only each of the key tumblers  120 - 123 , but also the positioner tumbler  13 . Lock plug  9  is configured such that the longitudinal or axially directed force applied by the user to insert customer key  16  into keyway  10  and to retract tumblers  13  and  120 - 123  also shifts lock plug  9  axially inwardly into lock barrel  5  until the outer collar  88  of lock plug  9  engages collar shoulder  68 , as shown in FIG. 51, to define a second axial position of lock plug  9  within lock barrel  5 . The second axial position of lock plug  9  is shown in FIGS. 51-54. In the second axial position of lock plug  9 , as shown in FIG. 51, inner keeper tumbler  17  is spring biased outwardly to engage keeper shoulder  8 , such that contact between outer collar portion  88  and collar shoulder  68 , and inner keeper tumbler  17  and positioner shoulder  7 , positively retains lock plug  9  in the second axial position (FIGS.  51 - 54 ). The shifting of lock plug  9  axially from the first axial position shown in FIGS. 47-50 to the second axial position shown in FIGS. 51-54 also shifts positioner tumbler  13  into tumbler groove  6 . As best illustrated in FIG. 52, when customer key  16  is removed from keyway  10 , key tumblers  120 - 123 , as well as positioner tumbler  13 , are biased radially outwardly into tumbler groove  6  to prevent rotation of lock plug  9  relative to lock barrel  5 . Both the inner keeper tumbler  17  and outer keeper tumbler  14  remain extended, and serve to positively retain lock plug  9  in the second axial position, yet permit selected rotation of lock plug  9  between the locked and unlocked positions. 
     The axial shifting of lock plug  9  from the first axial position (FIGS. 47-50) to the second axial position (FIGS. 51-54) serves to disable dealer key  15  to provide the customer with security. As shown in FIG. 53, when lock plug  9  is in the second axial position, if a dealer key  15  is inserted into keyway  10 , key tumblers  120 - 123  will be retracted, however, positioner tumbler  13  will remain fully extended within tumbler groove  6 , thereby preventing rotation of lock plug  9  relative to lock barrel  5 . Hence, dealer key  15  will no longer unlock lock system  1 . 
     With reference to FIG. 54, when lock plug  9  is in the second axial position, it may be removed from lock barrel  5  for repair, re-keying and/or replacement by insertion of control key  12  into keyway  10 . As noted above, the bits  162  on control key  12  are configured to retract all of the key tumblers  120 - 123  and both of the keeper tumblers  14  and  17 , but will not retract positioner tumbler  13 . However, since positioner tumbler  13  is located within lock barrel  5 , the retraction of keeper tumblers  14  and  17  permits the user to axially withdraw lock plug  9  from lock barrel  5 . In this manner, lock plug  9  can be readily removed from lock barrel  5  to be repaired, or re-keyed, and subsequently inserted back into lock barrel  5 . 
     The reference numeral  1   a  (FIGS. 55-58) generally designates another embodiment of the present invention, having a modified latch assembly  185 . Since lock system  1   a  is similar to the previously described lock system  1 , similar parts appearing in FIGS. 1-54 and FIGS. 55-57 respectively are represented by the same, corresponding reference numerals, except for the suffix “a” in the numerals of the latter. In lock system  1   a , latch assembly  185  has a somewhat simplified construction, comprising a lock housing  186  and a combination handle/latch  187  mounted therein. Latch  185  is particularly adapted for use in conjunction with storage areas associated with recreational vehicle  2 , such as exterior storage compartments  24  (FIG.  1 ). In the illustrated example, hinged doors or closures  25  provide access to the associated storage compartments  24 . Latch  185  is preferably mounted adjacent an upper edge of door  25 , while the opposite, bottom edge of door  25  is hinged to the trailer body  22 , such that door  25  is shifted to its open position by pivoting the door outwardly and downwardly. 
     The lock housing  186  of the illustrated latch  185  has a flush mount construction, comprising an exterior flange  196  which is positioned against the outer surface of door  25 . Latch housing  186  also includes a central recess  197  in which a combination handle/latch member  187  is slidably mounted. A handle portion  198  of handle/latch  187  includes a finger grip  199  to facilitate shifting the combination handle/latch  187  vertically, as oriented in FIG.  55 . Combination handle/latch  187  also includes a latch portion  200  with an outwardly protruding hook or catch  201  that mates with a striker plate  202  on trailer body  22 . A coil spring  203  is positioned between latch housing  186  and combination handle/latch  187  to bias combination handle/latch  187  to a normally extended, locked position, as shown in FIGS. 55 and 56. To open latch  185 , the operator simply manually grasps finger grip  199 , and shifts the same downwardly, against the biasing force of coil spring  203  to the fully retracted or open position shown in FIGS. 57 and 58. 
     Lock housing  186  includes a lock barrel  5   a , with a lock plug  9   a  received therein, which are substantially identical to the lock barrel  5  and lock plug  9  described hereinabove. When lock plug  9   a  is in the locked position, the axially extending pawls  98   a  extend into the path of motion of the latch portion  200  of combination handle/latch  187 , and thereby prevent combination handle/latch  187  from being shifted to the unlocked position. When lock plug  9   a  is rotated to the unlocked position, pawls  98   a  are shifted out of the path of movement of latch member  200 , so that combination handle/latch  187  can be shifted to the open position. Lock plug  9   a  and barrel  5   a  are substantially identical to the above-described lock plug  9  and barrel  5 , and use three keys to provide customers and sales personnel with easy access to the lockable storage compartments and/or other areas of numerous vehicles, yet can be readily converted to personalize the locks of a specific vehicle after it is sold to provide the buyer with security. 
     In the foregoing description, it will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed herein. Such modifications are to be considered as included in the following claims, unless these claims by their language expressly state otherwise.