Load bed lift-roof cover

An attaching system for a lift-roof cover pivoting substantially about a fixed forward wall upper edge via application of rear hatch technology of the prior art for conventional cab high covers together with attachment means in the form of linkages. The attaching system for mounting to a load bed supports multiple functions providing convenience in distribution and installation processes; in particular facilitating use of processes employed for conventional caps with respect to shipping and storage. The system includes lift-roof to forward wall stop and side retainer means supporting improved functional integrity and security. Also included are draw latches supporting levels of operating convenience demanded for lift-roof applications. Simplified manufacturing adaptation of a conventional cap is supported by pre-assembly of key subassemblies. Capability for completing all functional adjustments before shipping supports installation simplified to levels suited to needs of multiple location installers experienced only with conventional covers of the prior art.

CROSS-REFERENCES TO RELATED APPLICATIONS

© STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not Applicable.

BACKGROUND OF THE INVENTION

(1) Technical Field

The invention pertains to lift-roof covers for use with load beds of light trucks, providing improved access to the load bed and extending functions to other uses, with major focus upon achieving these benefits in a manner best accommodating manufacturing and distribution processes broadly in use relative to conventional fixed mount cab high covers (caps) of the prior art. Applicable US classifications include 296/100.1, 100.6 hinged load covers, 296/165 expansible or collapsible vehicle body, 296/176 expansible/collapsible from a first to a second configuration for camping. The disclosure describes key improvements beyond the concept described by U.S. Pat. No. 5,102,185, these improvements providing simplification in manufacturing processes and improvements in convenience of installation and operation to levels approaching those for conventional fixed mount caps (cab high covers) of the prior art. These improvements also increase the functional reliability of the complete lift-roof cover system and make possible enhanced aesthetic appeal by eliminating obvious appearance differences from conventional fixed mount caps of the prior art which have demonstrated highest user acceptance levels. In particular, objection has been made to separation lines between the forward wall and the lift-roof/cap shell when these are visible in side view. The application to a new use of existing technology for hinging and weather sealing rear hatch assemblies for fixed mount caps of the prior art overcomes this deficiency, while supporting functional and economic benefits associated with use of technology which is familiar to practitioners of the art to which the invention pertains.

(2) Description of Related Art

Through review of the prior art defined in patents relating to pickup truck load bed covers issued subsequent to Lake, U.S. Pat. No. 5,102,185, it can be seen that much effort has been focused on inventing alternate means to provide improved access for loading/unloading and facilitating adaptation to uses beyond cargo protection while also making available a roof height equal to or greater than that of the vehicle cab. Examples include the following:

Ekonen et al, U.S. Pat. No. 5,104,175, and Herndon, U.S. Pat. No. 5,951,095, describe transformable cover assemblies which unfold from a low profile on the load bed to provide full enclosure with a roof level equivalent to that of a cab high, fixed mount cap of the prior art. However, they add complexity while giving up significant degrees of security and integrity of appearance with the vehicle when in the cab high operating mode.

Aragon et al, U.S. Pat. No. 5,516,182, Herzberg et al, U.S. Pat. No. 5,203,603, and Hutchinson, U.S. Pat. No. 5,655,809, describe telescoping cab high covers having rigid outer paneling. These concepts provide better cargo security, but add significant complexity and also fail to provide the fully integrated appearance provided by most conventional, fixed mount, molded caps.

Fowler, U.S. Pat. No. 6,471,280, describes a cover with hard molded shell but, in order to provide improved loading access, requires removal of the shell, an obvious inconvenience.

Baldwin, U.S. Pat. No. 6,439,647, Dence, U.S. Pat. No. 6,394,532, and Lambden, U.S. Pat. No. 6,007,137, describe cab high rigid covers pivoting from one or both sides in a manner providing increased interior volume as desirable for adaptation to camping or improved side loading access. However they fail to provide improved access from the rear suitable for loading popular wheeled equipment.

Harkins, U.S. Pat. No. 5,209,543, describes an apparatus for enclosures such as pickup bed tops, including a pair of folding top panels longitudinally hinged for closing along the top centerline. In order to achieve the benefits of lift-roof improved access loading from the rear, considerable and costly complexity is added.

Medlin, U.S. Pat. No. 5,595,418, and Enninga, U.S. Pat. No. 5,104,175, describe means for mounting a cap to a load bed in ways accommodating pivotal rotation of the complete camper shell about a forward axis by lifting from the rear. However, significant complexity appears to be added in hardware and processes necessary for installation and acceptable function. Furthermore, sealing at the forward wall to load bed interface is not addressed.

Moore et al., U.S. Pat. No. 5,421,633, describes a camper shell intended for mounting directly to a truck frame on a vehicle assembly line, adaptable to having its roof pivotally raised from the rear and having flexible walls for camping attached and/or removed. Moore et al appears focused on application of lift-roof functional benefits via a high production volume vehicle assembly process requiring high levels of manufacturing tooling investment and does not appear to address needs of manufacturing and distribution systems in place within the conventional cap industry.

The concepts cited above provide various benefits beyond those provided by conventional fixed mount caps of the prior art. In most cases compromises are introduced which are evidently unacceptable to most purchasers of fixed mount, molded caps (historically comprising the primary market for pickup truck covers), who demand an appearance well integrated with styling of the vehicle, together with secure, weatherproof enclosure of the load bed to a height matching that of the vehicle cab. It would appear that Enninga and Medlin are able to retain all key functional and aesthetic benefits provided by conventional caps as long as they are used in the closed condition. When in the open condition cargo space is compromised, due to intrusion of the cap forward wall, which moves rearward as the cap shell is raised and introduces issues with respect to sealing to the load bed forward wall. Also, complexity introduced in the components and associated processes necessary for installation become of particular concern where installation may be completed at multiple locations by individuals with limited experience relative to the product. Therefore, objects of my invention include to provide the benefits of improved access for loading and easy adaptation to alternate uses while minimizing complexity in the installation process and/or costs in added hardware and avoiding compromises relative to benefits already provided by conventional fixed caps of the prior art.

Grise, U.S. Pat. No. 4,452,482, and McGaughey et al, U.S. Pat. No. 4,461,185, describe hatch frame construction for pickup truck caps including an integral hinge for supporting a hatch door in a weatherproof manner with location close to the cap roof edge. These patents are of referent interest in describing adaptation of radius door technology to lift-roof cover application

Ely et al, U.S. Pat. No. 6,179,350, describes a draw latch and various means for providing resistance to keep the members of a latch assembly in a variety of given positions and addresses need for manually raising a catch in order to effect disengagement.

Gromotka, U.S. Pat. No. 5,478,125, describes a draw latch in which rotation of the lever initially disengages the catch and positive contact between the lever and latch arm at a distance from the latch pivot causes the hook arm to kick out. Objects include to provide these functions with parts which are few, durable and reliable in all functions.

P. R. Gley et al, U.S. Pat. No. 3,519,298, describes a positive lock for toggle catch, or draw latch, permitting concomitant release of the catch and movement of the handle to an open position.

The above draw latch patents address need for one-handed convenience in operation. Various methods are described as used in the prior art for positioning handles and latch arms to support convenient operation. Plastic inserts have been employed where corrosion from exposure to the elements could otherwise impair function. Metal-to-metal frictional methods are commonly employed in order to support low cost. However, it would appear that, in practice, most friction or interference methods tend to result in high efforts and/or variation in effort due to wear and/or manufacturing variability. Such methods may be adequate to temporarily retain latch handles to an open position, because full hand strength may be conveniently applied to effect release. However, the control effort with respect to a latch arm pivoting from a latch handle needs to be relatively low in order to support convenient operation, which requires moving the latch arm independently of the handle either immediately before moving the handle, or simultaneously with handle operation, but in any case as a fluid one-handed movement. Accordingly it is an object to provide a draw latch which supports convenient positioning of component parts in operation by applying reliable methods to draw latches having other characteristics suited to lift-roof cover application. This may be best achieved with concepts depending on zero resistance beyond that of a free pivot and force of gravity, or otherwise with a more reliable method of providing frictional resistance than generally employed in the prior art.

SUMMARY OF THE INVENTION

To meet expectations with respect to product attributes broadly demanded within the primary market containing the majority of potential lift-roof cover users, these attributes must not be significantly compromised. Of particular importance for meeting needs of customers through the total delivery chain are convenience in manufacturing, distribution and installation as well as in end use. Accordingly, objects include to provide a forward wall and attaching system which may be conveniently pre-assembled and stored ready for assembly with minimal rework to a molded reinforced plastic cover of the prior art (generally limited to removal of material as needed to attach added hardware), together with an attaching system simplifying the process of installation to a vehicle load bed while supporting shipping, handling, storage methods employed for conventional caps of the prior art. Subassemblies incorporating draw latches and lift assist struts (plus rigid support struts and rigid support strut engagement means) are also used supporting these objectives. Draw latches have been uniquely developed for lift-roof application to provide reliable operating convenience.

To satisfy users, opening and closing operations must be conveniently completed by one person. Available draw latches of the prior art have been found lacking in functions necessary for such convenience. Latches on each side of the cover need to be simultaneously operated with simple movement of one hand, both in closing/latching and releasing/raising the cover. This requires reliable friction means and operating geometry ensuring that, when the lift-roof cover has been lowered on the load bed and the latch handle is operated to effect engagement, the engaging latch arm can be conveniently positioned to complete engagement and, after operation to effect release, remain in a position allowing unimpeded lift-roof raising or lowering.

A preferred forward wall is adapted from technology applied to rear hatch doors for conventional fixed caps of the prior art, generally referred to as radius doors in the trade to which the invention pertains. Adaptation of extruded-frame-hinged-within-extruded-frame pivotal attachment allows the forward wall to lift-roof structure interface joint to be inboard of the lift-roof side walls and hidden as viewed from outside of the vehicle, a valuable aesthetic benefit. Related benefits of applying this proven technology to a new use include simplified systems for lift-roof to forward wall hinging/sealing and orientation/position adjustment of the forward wall relative to load bed.

A novel forward wall to load bed attaching system is in the form of a linkage which supports multiple functions, including providing (a) means for adjusting location of the forward wall on the load bed and orientation of the forward wall to achieve effective sealing in closed condition between forward wall, lift-roof and load bed; (b) means of conveniently completing installation or removal from the vehicle load bed without fully removing attaching fasteners (c) in conjunction with lift assist struts, means to hold the forward wall to a closed position relative to the lift-roof with all components secured above a plane across lower edges of the molded lift-roof, so that the complete lift-roof cover may be shipped, handled and stored prior to installation using the same methods employed for a conventional fixed mount cap of the prior art.

In use, the lift assist struts are mounted between the load bed and lift-roof structure in a manner (a) facilitating sealing at the forward wall to lift-roof interface by loading the lift-roof forward against the forward wall and (b) adding lateral constraint in location of the lift-roof relative to load bed, providing protection from damage which might otherwise result, for example, from severe wind gusting immediately on raising the lift-roof.

A durability concern for conventional caps of the prior art has related to effects of severe shake, as associated with some modes of heavy duty model pickup operation on rough road surfaces. Without countermeasures, lift-roof structure side wall forward lower edges have increased sensitivity to lateral vibration compared with a conventional cap, in which the side walls are integral with the forward wall. Such vibration is prevented by incorporation of side wall retainer means between the lift-roof structure and the forward wall structure. To accommodate dimensional variability, these units incorporate means for adjustment of relative lateral position.

The use of frame-hinged-within-frame radius door fabrication technology in a forward wall to lift-roof attachment system results in forward loads imposed by the lift assist struts being transferred to the forward wall by the hinge interface when the lift-roof is in a raised position. Rigidity of the hinge interface protects the seal from excessive compression in upper locations, so that with the lift-roof closed and without countermeasures, forward loading is transferred primarily to the lower edges of the inverted U shaped lift-roof side wall to forward wall interface. This results in the seal and inner and outer frames deforming toward the lower edges to a degree eventually impairing both sealing and positioning of the lift-roof on the load bed. To avoid these conditions and provide precise control of closed location of the lift-roof relative to the forward wall, means of adjustable forward wall closure stop are needed. This is achieved cost effectively by integrating such means of adjustable stop with the adjustable lift-roof side wall retainers at each side of the lift-roof cover. These integrated units allow closure position to be set simultaneously with side wall retainer engagement during assembly, protecting sealing function between the lift-roof and the forward wall and preventing vibration of lift-roof side walls relative to the forward wall, as well as increasing security from unauthorized forced entry.

Designing for flex under severe operating conditions has become broadly recognized as necessary for structures such as tall buildings and bridges in order to achieve reliability with acceptable cost. This concept may have been less broadly recognized in automotive accessory applications and, perhaps as a result, fracturing of early molded cap shells was not uncommon, particularly in cold climates. Therefore, manufacturers have developed caps which better absorb flex. Severe operation results in significant torsional flexing of most pickup truck frames, much of which is transmitted to the load bed. If ignored, the effects add cost in reliability and other functional respects. Flex may be less of a concern with low frequency twist, as induced by normal off-road operation. However, pickups, particularly heavy duty models, may induce severe lateral shake due to high rate suspension systems which, under some light load operating modes on rough road surfaces, instead of fully absorbing irregularities, cause high frequency shake to be transmitted to the load box. Accordingly, it is an object of the invention to address issues of structural flex under operating conditions in lift-roof cover application.

In summary, the object of my invention is to add novel improvements with respect to convenience, cost and reliability affecting assembly, distribution, installation and use while providing a combination of advantages relative to fixed mount covers of the prior art as described in the parent U.S. Pat. No. 5,102,185 and fully maintaining the benefits already provided by conventional bed covers of the prior art. Further objects and advantages will become readily apparent to those skilled in the art to which the invention pertain upon reference to the following detailed description of a preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG. 1: The lift-roof cover10is mounted on a load bed11including side walls12fabricated so that the outside vertical surface13of the load bed wall12is continuous with the upper, substantially horizontal surface15of the wall12and the surface15likewise is continuous with an inside vertical flange16formed approximately at 90 degrees where it joins the upper surface15, the flange16serving to add rigidity to the upper surface15, as needed under vertical loading, and extending downward typically one to two inches. The flange16is fully accessible along most of the length of the load bed11between the load bed forward wall17and rear end18. Side walls19at left and right sides20,21respectively of a lift-roof structure22incorporate windows14and are joined at their lower edges23to substantially horizontal structural rails24which terminate along their length at an inner edge25almost directly above the load bed flanges16. The rails24and side wall lower edges23match contours of the upper surfaces15of the load bed side walls12. Sealing means26are mounted along the lower surface of the lift-roof cover rails24to provide weather sealing between the load bed upper surfaces15and lift-roof structure22when closed.

Referring toFIGS. 1,2and4: In a preferred embodiment the lift-roof structure22is pivotally attached to a forward wall structure28extending upward from the load bed wall17behind the cab30, by means of an inverted U shape outer frame31hinged to an inner frame32of matching shape with sealing means33at side interfaces34between the outer and inner frames31,32. The outer frame31is attached to a forward opening surround36in the lift-roof structure22and the inner frame32contains glass38retained by a horizontal closure member40. The outer and inner frames31,32are attached to each other at an upper lateral hinge interface41by telescopically assembled interlocking extruded male and female hinge halves42,44, respectively, of a sectional form similar to those illustrated by McGaughey et al, U.S. Pat. No. 4,496,185 (FIG. 1a) and Grise, U.S. Pat. No. 4,452,482 (FIG. 2).

Vertical adjustability of the forward wall28relative to lift-roof22is needed to ensure correct relationship of the forward wall lower edge46relative to side wall rails24and the interfacing load bed11, in closed condition. This adjustment may be made when the forward wall28is first installed to the lift roof structure22during the assembly process by control of a range of overlap47between the lift-roof22and the outer frame31to which the lift-roof22is attached. If adjustment is later needed relative to a load bed11with which the lift-roof cover10is to be used, increased convenience is desirable. Therefore, in a preferred embodiment, the forward wall28may include a lower member48adjustably attached via accessible attachment means50. Relative rigidity of the hinge interface41protects the upper seal interfaces from excessive compression. However, in a closed condition forward loading is transferred disproportionately toward the lower edge52of the seal interface34by the lift-roof side walls19. This results in a tendency for the sealing means33and interfacing radius door frames31,32to be distorted toward the lower edge52, eventually impairing both sealing and positioning of the lift-roof22on the load bed11. To prevent these conditions and provide improved control of closed location of the lift-roof22on the load bed11and relative to the forward wall28, forward wall to lift-roof structure adjustable stop and side retainer means54are employed at each side.

Referring toFIGS. 1,2,5and6: Reliable weather sealing between the forward wall28and lift-roof structure22below the hinge interface41is achieved on each side of the forward wall28with auxiliary sealing means60mounted to the inner frame outer surface62and seating against the facing inner surface64of outer frame31. At lower levels substantially vertical surface continuation66below the inner frame outer surface62faces a matching surface continuation68below and preferably coplanar with the outer frame surface64and inside edge25of rail24, so that seal70mounted to said lower surface continuation66seats against the matching outer surface continuation68when the lift-roof22is closed. The lower seal70extends forward from below the auxiliary seal60, so that rain water running down the forward edge of seal60drops onto seal70and is carried over the load bed forward wall17.

Referring toFIG. 1andFIG. 3: Further improvement results from the use of draw latches72uniquely developed for convenience in operation of the lift-roof cover20. Improved draw latches72are mounted to latch and strut pivot mount brackets73attached to each lift-roof rail24to form a part of the lift-roof structure22. In the manufacturing process, the draw latches72and lift assist struts74together with rigid struts75are pre-assembled to the brackets73to form latch and strut pivot mount subassemblies76, which are then held for installation to the lift-roof structure22, thus simplifying the final assembly process. Lifting force exerted by the lift strut74tends to distort the lower edge23of the side wall19. Because such force is absent in a conventional fixed cover installation to a load bed, stiffness is typically insufficient to avoid visible distortion in a lift-roof adaptation, particularly under reflected light conditions. Visible distortion can be eliminated by increasing bending and torsional stiffness along the side wall structural rail24. However, a less costly method in adapting a cover of the prior art to lift-roof function without degrading appearance has been found to be by transferring strut lift force to an upper area of the side wall19as a side force. Accordingly, latch and strut pivot mount bracket73incorporates side wall structural reinforcing means79projecting upward from a level close to the lower edge63of the window14against the lift-roof side wall19and hidden from external view behind window frame structure65typically present in a conventional cab high cover of the prior art.

Some caps of the prior art are molded with an inside downward oriented lip67, so that the lip67overlaps the flange16, thereby providing control of lateral location when sitting on a load bed11. In a lift-cap application such a lip is removed in locations adjacent to components where interference may otherwise result, as at forward wall attaching linkages80and latches72. For lift-roof adaptation of molded caps not having such a lip, brackets73mounted to the rails24, each with an inboard surface68substantially coplanar with the load bed flange16provide a convenient option of adding a lateral locating means69, optionally attached by rigid strut attachment means78, the locating means69having a ramped leading edge71suitable for providing precise lateral location on the load bed11when the lift-roof22is closed.

Referring toFIG. 1andFIG. 2: A preferred forward wall to load bed attaching system is in the form of a linkage80at both sides19of the lift-roof cover10, incorporating pivot links81, attached via fastening means82to a lower part83attached to, or forming part of, the forward wall28at a pivot link upper slotted end84, and via fastening means85to a load bed inner flange forward attaching clamp means86at the pivot link lower end87.

In a preferred embodiment the load bed forward attaching clamp means86is rigidly attached to a rearward attaching clamp means88via a bar89, so forming a clamp link90. Said rearward clamp means88is attached via fastening means91to a lower end92of a forward wall orientation link93. An upper end94of the orientation link93is attached via fastening means95at an upper location96to each side of the forward wall structure28. In a preferred embodiment the upper location96is attached to, or forms a part of, inner frame32, thus facilitating pre-assembly. Thus, the forward wall structure28, together with four fastening means82,85,91,95, pivot link81, clamp link90and orientation link93forms a linkage80at left and right sides of the forward wall28. When fastening means82,85,91,95are loosened, linkage80provides freedom of movement of component links81,90,93, enabling adjustments in position of the links relative to forward wall structure28and the vehicle load bed11.

Multiple functions are accomplished with use of attaching linkage80: with fastening means82,85,91,95tightened to provide rigid joints, support is provided to control orientation of the forward wall28relative to the load bed11, plus means are provided for adjusting longitudinal location of the lift-roof cover10on the load bed11and adjusting orientation of the forward wall28relative to load bed11to achieve effective sealing between the forward wall28, lift-roof22and load bed11in a closed condition; means are also provided to complete installation or removal from the vehicle load bed11without need to fully remove attaching fastening means82,85,91,95; in conjunction with other components, means are provided to hold the forward wall28to a closed position relative to the lift-roof22with all components secured above a plane across lower edges23of the molded lift-roof22, so that the lift-roof cover10may be shipped, handled and stored using the same methods employed for a conventional cap of the prior art.

Preferred fastening means82,85,91,95for the attaching linkage80include friction lock-nuts107, so that fastening means82,85,91,95may be set with zero clamp load and yet maintain reliable attachment (as needed to facilitate shipping). The friction lock-nuts107are used in combination with bolts97suitable for force-fitting to structural components so that tightening of fastening means82,85,91,95is largely reduced to a one handed operation. Dimensions may be set so that, in event of looseness at one location, as due to error, linkage engagement is still retained with the load bed side wall flange16. The lift-roof cover10is prepared for shipping with the forward wall28held to a closed position as described above. This is accomplished by installing the latch and strut pivot mount bracket sub-assemblies76to the lift-roof structure22with lift-assist struts74and strut lower pivot brackets98positioned along the rail24, forward of the latch and strut pivot bracket73with the brackets98held in the linkage rear clamps88, and with clamp links90and pivot links81in an upper, approximately horizontal position shown by the upper broken outline inFIG. 2.

Referring toFIGS. 8,9, and10: Where access between the load bed side wall inner flange16and outer surface13is blocked or limited, as by load bed wall structure100, toward the forward wall17, a modified form101of the preferred linkage80may be employed. An extension member102of relatively rigid form such as having an angle cross section and of high strength material, may be attached under clamp fasteners103,104inboard of the flange16. The extension member102allows use of a forward clamp means103at a position where adequate access is available between the flange16and the side wall outer surface13rearward of attachment of the extension member102to pivot link105. The desired lateral, vertical and longitudinal control of forward wall positioning on the load bed11is thereby provided. A retaining angle bracket106with adjustable means of attachment108to a horizontal face109on the extension member102may be used to engage the side wall flange16where clearance between the flange16and blocking structure100is limited. Where no clearance is available, adjustments may be made to ensure linkage contact is maintained at the forward end111with the flanges16at both sides of the load bed11, so providing control of lateral positioning at the forward wall28relative to the load bed11.

Referring toFIG. 1andFIG. 2: Following installation of the latch and strut pivot bracket assemblies76to the rails24with the lift assist struts74lying forward along the rails24, the forward wall28, complete with attaching linkages80at each side, is installed and clamped into position in the same manner as for a conventional cap rear hatch113of similar construction. The forward wall28is then held to a closed orientation relative to the lift-roof structure22and the linkage rear clamp means88are clamped to the strut lower pivot brackets98to maintain the forward wall closed relationship to lift-roof22. The forward wall lower members48are then checked and, if necessary, adjusted for relationship to the lift roof lower edges23. Side retainer/forward stop means54are, at this stage, installed to the rails24at metal-to-metal interfacing component positions and should require no further adjustment when the lift-roof cover10is installed to a load bed11.

Referring toFIGS. 1,2,13and14: Functional improvements also include rearward mounting of lift assist struts74between the vehicle load bed11and the lift-roof rails24in a manner facilitating full closure at the forward wall to lift-roof seal interface34when the lift-roof22is lowered by forcing the lift-roof22forward against the forward wall28, and also adding lateral constraint in location of the lift-roof22relative to load bed11. Geometry of the lift assist strut action is such that, with the lift-roof22in a lower, closed position, vertical loading of the lift-roof22on the lift assist struts74exceeds vertical force provided by the lift assist struts74, so that the lift-roof22will remain in a lower, closed position unless manually raised. The lift assist struts74are located close to the rail inner edges25and the load bed flanges16so that, if the lift-roof structure22remained unlatched in error, the struts74constrain its lateral location. When the lift-roof structure22is raised above the fully lowered position, the forward force provided by the lift assist struts74pushes the lift-roof22against the forward wall structure28at the hinge interface41. As the lift-roof22is lowered toward closed, an increasing forward component of loading in the lift assist struts74causes an increase in forward deflection of the forward wall28at the hinge interface41relative to the forward wall lower edge46due to combined effect of flex in the forward wall structure28and flex in the load bed side walls12in the vicinity of the flanges16under tensile force transferred through orientation links93, until a lift-roof position114(shown in broken line inFIG. 14) is reached where full closure has occurred at the forward wall to lift-roof seal interface34. Due to the forward deflection of the forward wall28at the hinge interface41, relative to the forward wall lower edge46, position114occurs prior to full closure with the load bed11, generally when the lift-roof22is at least a half inch clear of the load bed rear end18.

Referring toFIG. 11: Installation is first a process of installing low friction/low stiction load bed interfacing seals26and positioning the lift-roof cover10on the load bed11, in the same way as for conventional caps. After checking and, if necessary, adjusting function, the draw latches72are engaged with the flanges16to hold the lift-roof cover firmly in position.

Referring toFIG. 12andFIG. 2: The forward wall adjusting linkage rear clamp fasteners91are then loosened to release the strut lower pivot brackets98, and the linkage80is rotated downward in direction of arrow B so that clamp means86,88may be swung down clear of the load bed flange16, then moved laterally inboard under the flange16. The clamp link89is then swung upward in direction of arrow C to engage the flange16. If necessary, orientation link lower end92is at this time adjusted to a position where the forward wall28is oriented with a closed relation to the lift-roof22. Forward clamp means86is moved upward, as accommodated by slot adjusting means84of pivot link81, so that flange16is engaged by forward clamp means86. Clamp fasteners85,91are then tightened to appropriate torque levels, followed by tightening of fasteners82and95.

Referring toFIGS. 2,13and14: The latches72are next released and a set height installation strut120is attached by temporary attachment means, (such as adhesive backed Velcro),122at one end to the lift roof structure ceiling123adjacent to the lift-roof rear hatch113. The lift-roof structure22is then carefully raised until the installation strut lower end125falls forward to the rear edge126of the load bed11and is allowed to sit on the tailgate128. Lift assist strut lower pivot bracket98, having been released when forward adjusting linkage fasteners91were first loosened, may now be rotated in direction of arrow D to a location such as rear tie-down mountings where the lower pivot bracket98can be bolted to the load bed11. (Referring now toFIG. 2andFIG. 14): After removing the set height installation strut120and lowering the lift-roof22, operating relationships for lift-roof side retainer/stop units54are checked and latches72again engaged for closed mode operation.

Referring toFIGS. 1,4,5and6: Without countermeasures the lift-roof side wall forward lower edges132have increased potential for lateral vibration as compared with a conventional load bed cover, in which the side walls are integral to the forward wall. Such vibration is prevented cost effectively with stop and side wall retainer means54attached to the lift-roof22at left and right sides20,21. To accommodate variability in manufacture, stop and side wall retainer means54incorporate means for adjustment of lateral relative position134.

A preferred lift-roof adjustable side wall retainer and forward stop means54includes a first part or bracket135attached to a mount136attached to and/or forming a part of the lift-roof structure22, the bracket135having a face137on a substantially vertical and longitudinal plane with a ramped leading edge138to guide engagement and prevent blocking due to minor misalignment of interfacing parts135,83, the face137being substantially coplanar with a mating face139on flange83, attached to or forming a part of the forward wall28. The bracket135and flange83each also have interfacing stop surfaces140,141so that, as the lift-roof22is lowered to a closed condition, the stop surfaces140,141make positive contact. The bracket135is attached to the mount136via fastening means142, comprising a bolt143passing through slotted and/or oversize holes134in the mount136or bracket135, the bolt143being retained by a friction lock-nut145. The bolt is constrained from rotation by interference or force fitting to one part, while an adjustment slot is provided in the other, thus allowing the friction lock-nut145to be torqued to provide clamping, or loosening of the bracket135relative to the mount136using one hand and one tool. The use of slotted and/or oversize holes134accommodates relative lateral position adjustment between the first part135and the mount136. By varying the thickness of spacing means146between the mount136and part135, longitudinal position adjustment of the part135relative to the mount136may also be provided. With the lift-roof22in a closed, lower position, the bracket135is set to bear forward against flange83attached to or forming a part of forward wall structure28. With the side retainer and closure stop adjustment means54, closure of the lift-roof structure22relative to the forward wall28may be set during the manufacturing assembly process as needed to ensure satisfactory sealing between the lift-roof structure22and the forward wall28and also to ensure that the possibilities of vibration of lift-roof structure side walls19relative to the forward wall28or of unauthorized forced entry are eliminated. It will be recognized by one skilled in the art to which the invention pertains that with simple rearrangement of components, the various described functions may be reversed between components attached to the forward wall28and those attached to the lift-roof22without departing from the scope of the invention. (Referring toFIG. 7): It will be also be recognized that an alternate bracket147may be easily fabricated to capture flange83on both sides and by similar means vertical capture may also be achieved.

Referring toFIG. 15andFIG. 16: Draw latches are used to draw and hold two structures together. The following describes limitations of two draw latches of the prior art and how they are improved to meet functional needs for lift-roof operation. A first over-center draw latch of the prior art150comprises a latch hook152, a latch handle154and a latch base156; the latch hook152being pivotally attached to the latch handle154at pivot means155, the latch handle154being pivotally attached to the latch base156at pivot means157. The latch base156is attached to a vertical surface158fixedly attached to, or forming part of, a first structure22and the latch hook152is used to engage a suitable engagement means16on the second structure11. In latched condition (shown in broken outline inFIG. 15), tension force passing through the latch hook engagement point159with the second structure11and through the latch hook pivot155, holds the latch hook152to the latched position until latch handle154is manually rotated away from the latch base156in direction of arrow L. Rotation of the handle154per arrow L away and down from the latch base156brings the tension force line “over center” across the latch handle pivot157toward a released condition (shown in solid line inFIG. 15), first lowering the latch hook152from engagement with the load bed flange16. To complete full release (referring now toFIG. 16), with upward rotation of the latch handle154in direction of arrow M, the latch hook152should be moved clear of the load bed flange16per arrow N. In reverse, with the cap shell22in the lowered position, downward rotation of the latch handle154per arrow0first moves the latch hook152per arrow P against the flange16. With relatively low rotational friction levels, the latch hook152can be conveniently held in the position shown in solid line inFIG. 15. using a thumb while, with the same hand, the handle154is rotated upward in direction of arrow Q, pulling the latch hook152into engagement with the load bed flange16. As the handle154is rotated further upward, the structures11,22are drawn and held to a latched condition.

The first draw latch of the prior art150, as available, is built with axial clamp friction between components152,154,156at pivot interfaces155,157so that, without force beyond gravity, components152,154tend to remain in whatever relative position they are placed. However it has been found that initial operating efforts are too high for convenience and the friction declines with use to levels where, with weight of the latch handle154bearing against the latch hook152, the latch hook152tends to fall under the flange16following initial disengagement, resulting in interference with the side walls15when lowering the lift-roof22from open, and/or re-engagement with the inner flange16when the lift-roof22is raised from closed.

Referring toFIGS. 1,17and18: In a preferred embodiment, first alternate improved draw latches72are mounted to the rails24and have latch handles164which, when rotated to a fully latched/closed position, pull latch hooks166into engagement with the load bed inner flanges16, thereby drawing the lift-roof22down to the load bed11. With appropriate vertical adjustment, this causes compression of sealing means26between the rails24and load bed side wall upper surfaces15and prevents significant movement relative to the load bed11. In the first improved draw latch72for use with a lift-roof cover, the latch handle164, in rotating downward, is positively limited at a lower position where the latch hook166hangs clear of engagement or interference with the flange16when the lift-roof22is raised or lowered. The latch base167is mounted against a vertical surface158forming a part of, or attached to, lift-roof side wall rail24, with the latch handle164pivoting from the latch base167and in a vertically upward orientation when in fully latched mode. As modified for the lift-cap application, the latch base167is formed at a lower end168to create a positive stop170for the latch handle164at a position where said latch handle is oriented down from its near vertical latched position and the latch hook pivot172is substantially inboard of the latch handle pivot174, following release of the latch hook166from the load bed flange16. The first improved draw latch72is substantially free of rotational friction drag at the latch hook pivot attachment172and the latch hook166is modified from the first draw latch of the prior art150as by removal of material176so that, when the handle164is rotated downward against the stop170, the latch hook166can hang freely and remain clear of the load bed wall upper surface15. This allows the lift-roof structure22to be freely lowered toward a closed position before, with easy one-handed operation, moving and holding the latch hook166under the flange16, while rotating the handle164toward vertical to engage the latch hook166with the flange16and pull the lift-roof structure22to a fully latched position.

Referring toFIGS. 19,20and21: A second over-center draw latch of the prior art178includes a base179, a latch handle184pivotally attached to the base179at a pivot185, and a latch hook180pivotally attached to the handle184at a hook pivot183. Retention means181temporarily retain the latch handle184in an upward vertical orientation with the hook pivot183in a lower released position (shown inFIG. 20). However, the latch hook180, following disengagement, remains in a position determined by relation of its center of gravity182to its pivot183, about which it freely rotates. This position may be such as either to interfere with the load bed wall upper surface15when the lift roof22is lowered and re-engage the load box inside flange16when it is raised, or otherwise to fall clear and remain clear of the flange16when engagement is desired. The relation of the latch hook180to the latch handle184is such that its position cannot easily be controlled while also operating the handle184with the same hand.

Referring toFIG. 22andFIG. 23: In a second alternate improved latching means186suitable for lift-roof cover application, the addition of reliable friction means188acting relative to rotation of the latch hook190about its pivot192facilitates operation of the latching function as a one-handed operation, allowing simultaneous latching at left and right sides20,21when the lift roof cover10is closed. Reliable rotational friction drag is provided by use of leaf spring194bearing against a circumferential surface196of the latch hook190where the circumferential surface196wraps around the pivot pin192. It will be recognized by one skilled in the art to which the invention pertains that wear in the friction interface188between the leaf spring means194and the latch hook circumferential surface196will not quickly change normal force at the friction interface188. This is because, unlike friction methods commonly employed in over-center draw latches of the prior art, friction drag is controlled by spring deflection, which will be large relative to any change in deflection resulting from wear. Therefore, friction drag can be expected to be adequately maintained over a lift-roof cover functional lifetime. When the latch handle200is raised, the latch hook190is first lowered and, as the hook190clears the flange16, added friction drag exceeding the effect of gravitational force, which gravitational force otherwise causes the latch hook190to hang substantially vertically below hook pivot192, causes the latch hook190to be rotated inboard and upward with latch handle200in direction of arrow R. This ensures that, with the latch handle200retained to an upward vertical orientation, the latch hook190will not re-engage the flange16when the lift-roof22is raised to an open position, nor interfere with the load bed side wall upper surface15when the lift-roof22is lowered. Also, from this position, with the lift-roof22in a lowered position, if the latch hook190is first independently manually rotated substantially downward from its resulting position relative to the handle200following release, the added friction ensures that the latch hook190will move against, and be held against, the load bed inside flange16until the latch hook190has fully engaged, when the latch handle200is then fully rotated downward to draw the latch hook190upward.

The improvements of the present invention relating to a load bed lift-roof cover are defined by the following claims: