Abstract:
A rotary latch for selectively locking a closure, such as a tonneau cover, is provided with a joystick or toggle release lever. The joystick release lever enables the rotary latch to be installed in any position with respect to a remote handle because the joystick can be pulled in any direction, 360 degrees, to release the rotary latch. The joystick includes a trapped base supporting a spherical portion that is nested in a circular opening in the housing of the latch. The joystick is spring loaded, and is movable about its central axis in any direction, causing the base to pivot against the inside of the housing. The base of the joystick is positioned over a spring-loaded catch locking the rotary latch. As the base of the joystick rotates against the inside of the housing, it depresses the spring-loaded catch, releasing the rotary latch.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application Ser. No. 60/756,847, filed Jan. 6, 2006, which is incorporated herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a rotary latch. 
     2. Description of Related Art 
     Rotary latches are well known in the art, providing a strong, compact latching mechanism for many applications. A rotary latch generally includes a housing portion fixed to a first structure having a U-shaped slot configured to receive a post fixed to an opposing structure. A C-shaped latch is pivotally attached within the housing and arranged to rotate from a latched position within and perpendicular to the U-shaped slot to an unlatched position. In the latched position, the C-shaped latch and the U-shaped notch overlap to define a central opening configured to hold the post. In the unlatched position, the C-shaped latch is rotated toward the opening of the U-shaped slot, allowing the post to move into or out of the U-shaped slot. The C-shaped latch usually includes a catch on its body in an opposing position to the opening of the “C” relative to the pivot point of the latch. The catch is configured to act in concert with a trip lever pivotally mounted within the housing. The C-shaped latch and the trip lever are generally spring-biased. The C-shaped latch is biased in an open position and the trip lever is biased in a locked position. When the C-shaped latch is moved into the closed position, the trip lever is biased to engage the catch, holding the C-shaped latch in the closed position. The C-shaped latch is released by rotating the trip lever until it disengages from the catch. A stud is usually mounted to the trip lever for attachment of a release cable. Because of the configuration of the trip lever having a fixed pivot axle, it is necessary to arrange the release cable in a very narrow approach angle to the stud, in order to be able to pivot the trip lever with a minimal force exerted on and by the release cable. In the known arrangement, the release cable is generally aligned parallel to the housing of the rotary latch. Deviations from the optimal attachment of the release cable to the stud, with a tangential positioning of the cable relative to the pivot axis of the trip lever, unnecessarily increase the force required to release the rotary latch. The mechanical advantage available in the trip lever can therefore be lost by suboptimal positioning of the cable. Also, in different applications, it becomes necessary to modify the configuration of the trip lever and the stud so that the release cable can even access the stud. This necessitates the manufacture and stocking of multiple configurations of rotary latch assemblies, dependent upon the variety of applications used in a particular assembly. 
     It would be advantageous to provide a rotary latch system that provides the maximum available mechanical advantage regardless of the exact alignment of the release cable relative to the pivot axis of the trip lever. It would further be advantageous to provide a rotary latch system that improves the accessibility of a release mechanism in different applications without requiring the physical modification of the rotary latch. 
     BRIEF SUMMARY OF THE INVENTION 
     A rotary latch for selectively locking a closure, such as a tonneau cover on a pickup truck bed or the swing-up window on a pickup truck cap, is provided with a spring loaded toggle release lever, or joystick. The joystick enables the rotary latch to be installed in any position with respect to a remote actuating handle because the joystick can be pushed or pulled in almost any direction to release the rotary latch. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The present invention will become more fully understood from the following detailed description and the accompanying drawings, wherein: 
         FIG. 1  is a side view of a pickup truck with a tonneau cover and a rotary latch with joystick according to the invention. 
         FIG. 2  is a partially broken sectional view of the rotary latch according to the invention, mounted on  FIG. 1  pickup truck tailgate and tonneau cover, and substantially as taken on the line  2 - 2  of  FIG. 3 . 
         FIG. 3  is a front view of the rotary latch of  FIG. 2 . 
         FIG. 3A  shows various means for actuating connection to the joystick of  FIG. 3  and schematically illustrates the possibility of linking two (or more) latch mechanisms by means of their joysticks. 
         FIG. 3B  shows a power actuator to joystick connector according to  FIG. 3 . 
         FIG. 3C  shows an unlatched position of parts of the  FIG. 3  apparatus. 
         FIG. 4  is a pictorial view of the rotary latch of  FIG. 3 . 
         FIG. 5  is a bottom view of the rotary latch of  FIG. 3 . 
         FIG. 6  is a rear view of the rotary latch of  FIG. 3 . 
         FIG. 6A  is a fragment of  FIG. 3  showing the joystick in central cross section. 
         FIG. 6B  is a sectional view substantially taken on the line  6 B- 6 B of  FIG. 6 . 
         FIG. 7  is an end view of the rotary latch of  FIG. 3 . 
         FIG. 8  is an opposite end view of the rotary latch of  FIG. 3 . 
         FIG. 8A  is an exploded pictorial of a bracket for mounting the latch mechanism of  FIGS. 1-8 . 
         FIG. 9  is an exploded pictorial view of the housing of the rotary latch of  FIG. 3 . 
         FIG. 9A  is a pictorial view of the latch member and latch release member of the rotary latch of  FIG. 3 . 
         FIG. 10  is a side view similar to  FIG. 6 , but with the rear housing portion mostly removed. 
         FIGS. 11A-11H  depict the release sequence the main parts (only) of the rotary latch of  FIG. 3 . 
         FIG. 12  is an end view of the free end of the joystick of the rotary latch of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words “up”, “down”, “right” and left” will designate directions in the drawings to which reference is made. The words “in” and “out” will refer to directions toward and away from, respectively, the geometric center of the device and designated parts thereof. The words “proximal” and “distal” will refer to the orientation of an element with respect to the device. Such terminology will include derivatives and words of similar import. 
       FIG. 1  shows an application by way of example and not limitation, for the present invention. The invention is applicable in any enclosure requiring selective latching, and wherein the release of said latching can be accomplished by powered or manual actuation, electronically or mechanically, or by direct or remote control. In a motor vehicle  50 , e.g. a pickup truck, the present invention is applied for latching a door on a pickup truck cap or, as here shown, a tonneau cover  55  over a pickup truck bed cargo area  60  having a tailgate  65 . The tonneau cover  55  is movable between an open position (shown) and a closed position (shown in phantom). In the closed position, the tonneau cover  55  can be secured by a latch mechanism  100  releasably engaging a pin, or strike,  110  ( FIG. 2 ). The latch mechanism  100  is here indicated as being mounted on the tonneau cover  55  and the pin  110  on the tailgate  65 , respectively, but could on the tailgate  65  and tonneau cover  55 , respectively instead. 
     The latch mechanism  100  is attached to the inside of the tonneau cover  55  by a bracket  105 . A cooperating pin  110  is mounted to the tailgate  65 . 
     Referring further to  FIGS. 3A-3C , the latch mechanism  100  includes a joystick  130 . The joystick  130  is spring biased into a rest position (vertical as shown in the drawings), and as will be further disclosed, displacement of the joystick  130  from such vertical position triggers unlatching of the latch mechanism  100 . 
     Referring now to  FIGS. 5-10 , the latch mechanism  100  has a housing  140  formed of a left (in  FIGS. 7-9 ) housing portion  145  and a right housing portion  150 . 
     The left ( FIG. 9 ) housing portion  145  comprises an elongate longitudinally extending sidewall  145 A having a laterally and endwardly facing notch  145 B, an elongate longitudinal flange  145 C extending widthwise perpendicularly from and following one length edge of the sidewall, a perpendicular first end flange  145 D at the notched end of the sidewall and adjacent one end of the elongate flange  145 C, a narrow step-like end wall  145 E extending widthwise perpendicularly from the other end of the sidewall to about half the width of the adjacent end of the elongate flange  145 C, an extension wall  145 F extending longitudinally from the free edge of the end wall  145 E in a plane parallel to the sidewall  145 A, and a narrow end flange  145 G extending from the free end of the extension wall generally parallel to and spaced from the step-like end wall  145 E. 
     The housing portion  150  is preferably substantially a mirror image of the housing portion  145  except as follows. The housing portion  150  comprises a longitudinally and widthwise extending flange  150 H at the longitudinally extending edge  150 J of its notch  150 B, but omits parts comparable to the longitudinal flange  145 C, first end flange  145 D and narrow end flange  145 G of the housing portion  145 . 
     The left and right housing portions are joined by a pair of swaged bushings  175 ,  180  whose ends are fixedly received in respective apertures  155 ,  165  and  160 ,  170  in recessed portions of the sidewalls  145 A and  150 A. The swaged bushings  175 ,  180  each have a threaded interior passage  185  for receiving a threaded fastener (e.g. screw)  190 , for securing the latch mechanism  100  to the bracket  105  and to an alignment plate  195 . In  FIG. 3 , the bracket  105  is fixed to the tonneau cover  55  by bolt and nut units  194 . The left (in  FIGS. 5 ,  6  and  10 - 11 ) end of housing  140  defines a U-shaped channel, or notch,  198  for receiving the pin  110 . 
     The housing narrow end walls  145 E and  150 E space the housing extension walls  145 F and  150 F laterally inboard of the housing sidewalls  145 A and  150 A, at the width of the end flange  145 G. The extension walls  145 F and  150 F and end flange  145 G define the left (in  FIGS. 5 and 6 ) end portion of the housing as a narrow (compared to the width of the housing at the sidewalls  145  and  150 ) nose  196 . The narrowed nose  196  allows mounting of the housing very close (e.g. almost abutting as in  FIG. 5 ) the structure  65  (e.g. the truck tailgate) carrying the cooperating conventional pin  110 , even if the latter incorporates a radially projecting mounting flange, or the like, as indicated in the dotted line at  111  in  FIG. 5 . Moreover, and as will be noted in  FIG. 5 , since the narrowed nose  196  is spaced laterally inboard from both sidewalls  145 A and  150 A of the housing  140 , the housing  140  can be placed close to the pin supporting structure  65 , even with its orientation reversed, e.g. with its sidewall  150 A adjacent the pin supporting structure  65 , rather than its sidewall  145 A as in  FIG. 5 . Thus, not only can the latch mechanism  100  be mounted in any desired orientation (e.g. joystick up, joystick down, joystick left, joystick right, housing length axis vertical or horizontal or sloped, but in any of those orientations, the housing  140  can be placed close to or spaced from the pin support structure  65  with which the latch mechanism  100  latchingly cooperates. 
     The mounting bracket  105  here includes a main body and a mounting flange  106  perpendicular thereto. Slots  107  and  108  in the main of the bracket  105  and in the flange  106 , respectively, allow adjustment of the location of the bracket  105  with respect to the adjacent side of the housing  140  and structure (e.g. the tonneau cover  55  of  FIG. 1 ) on which the bracket is fixed. 
     To allow mounting of the housing  140 , in its contents, in any desired orientation, the bracket  105  may be fixed on either side of the housing  140 , e.g. either adjacent to the sidewall  150 A as seen in  FIG. 8 , or to the opposite side wall  145 A. Moreover, with the mounting bracket  105  fixed to supporting structure (e.g. the  FIG. 1  tonneau cover  55 ) by means of its mounting flange  106  ( FIG. 8 ), the housing  140  can be fixed in its joystick down orientation of  FIG. 8  or reoriented with the joystick  130  up. 
     The alignment plate  195  ( FIG. 8A ) has through holes  195 A spaced from each other widthwise of the plate  195  at the same spacing as the slots  107  and the bracket and bushing holes  155  and  160  in the housing portion  145  and holes  165  and  170  in the housing portion  150  so as to coaxially align therewith. Aligned with the holes  195 A are a pair of upper lugs  195 B and a pair of lower lugs  195 C adjacent the top and bottom (in  FIG. 8A ) edges of the alignment plate  195 . The lugs  195 B and  195 C protrude toward and are of width be snuggly received in the bracket slots  107 , as indicated in  FIG. 8 . With the screws  190  loosened to adjust the position of the housing  140  along the length of the slots  107 , the adjustment plate  195  positively prevents one of the screws  195  from rising above the other and so prevents tilting of the housing  140  in a plane parallel to the adjustment plate  195  and main portion of the bracket  105 , i.e. maintains the top and bottom plates of the housing  140  perpendicular to the length axis of the slots  107  of the bracket  105 . 
     The latch mechanism  100  ( FIGS. 9A and 10 ) includes a rotating latch member  200  and a rotating latch release member  205 . 
     As shown in  FIG. 10 , the latch member  200  and latch release member  205  are plate-like and pivotally mounted on the bushings  180  and  175 , respectively, which extend through corresponding holes  201  and  206  ( FIG. 9A ) therein. 
     The latch member  200  includes a C-shaped portion  235  to the left (in  FIG. 10 ) of the bushing  180  and a tail portion  255  on the opposite side of the bushing  180 . The C-shaped portion  235  includes an inner arm  240  and an outer arm  245 . The inner arm  240  and the outer arm  245  define a U-shaped channel, or notch,  250  therebetween. The tail portion  255  has a shallow notch  215  in its lower ( FIG. 10 ) edge. 
     The close flanking of the C-shaped portion  235  ( FIG. 10 ) of the latch member  200  by the extension walls  145 F and  150 F of the housing portions  145  and  150  helps prevent the C-shaped portion  235  from bending or cocking out of its intended operating plane. Further, the bearing of the end flange  145 G on the extension wall  150 F (as seen in  FIG. 5 ) helps rigidify the housing nose  196 . 
     The latch release member  205  includes a catch portion  260 . The catch portion  260  includes a step-like catch  265  and a shallow notch  230 . The catch  265 , as shown in  FIGS. 9A-11 , is configured to engage the tail portion  255  of the latch member  200 . The latch release member  205  further includes a lever portion  270 . The lever portion  270  and catch portion  260  are on opposite sides of the bushing  180 . The lever portion  270  is formed as a flange perpendicular to the remainder of the latch release member  205  and comprises a leg  271  extending substantially tangentially beyond the bushing and terminating in a foot  272  extending parallel to the axis of the bushing hole  206 . The foot  272  here includes an aperture  275 . 
     A torsion-type latch spring  210  is also concentrically mounted on the bushing  180 , and at one end engages the notch  215  in the latch member  200 . The spring  210  at its other end bears against the end wall  220  of the housing  140 , thereby biasing the latch member  200  in a counterclockwise direction (as seen in  FIG. 10 ). A second torsion-type spring  225  is mounted concentrically on the bushing  175 . The second spring  225  at one end engages the notch  230  in the latch release member  205 . The second spring  225  has its other end trapped behind the bushing  180  to bias the latch release  205  in a clockwise direction. 
     As shown in  FIG. 6A , a rivet  280  protrudes through the longitudinal flange  145 C in alignment with the aperture  275  and thus secures a first end  285  of a coil compression spring  290 . The compression spring  290  passes through the aperture  275  and is received within a cavity  295  in the joystick  130 . 
     The joystick  130  includes a flat circular base portion, or annular flange,  300  ( FIG. 10 ), a necked-down (here convex or substantially frusto-conical) central portion  305 , and an elongate cylindrical arm portion  310 . The joystick  130  ( FIGS. 6A ,  9  and  10 ) passes through a round aperture  315  in the flange  150 H of the right housing portion  150 . The flat circular base portion  300  of the joystick  130  is larger than the aperture  315 , so that the joystick  130  is retained within the housing  140 , with the base portion  300  bearing against an inner surface  316  of the flange  150 H of the housing  140 . The joystick  130  is biased into the aperture  315  by the compression spring  290  bearing between the base portion  300  of the joystick  130  and the longitudinal flange  145 C of the left housing portion  145 . The joystick central portion  305  tapers, from a diameter closely conforming to the aperture  315 , to the diameter of the cylindrical arm portion  310 . The profile of the outer wall  317  of the tapered central portion  305  can be linear or arcuate. 
     The compression spring  290  is partially compressed between the longitudinal flange  145 C ( FIG. 6A ) and the inboard end of the recess, or cavity,  295  in the inboard end of the joystick  130 , even in the relaxed (unactuated) position of the joystick shown. The rivet  280  is received in the first end  285  of the spring  290  to prevent the spring  290  from sliding sideways along the flange  145 C. The function of the rivet  280  can also be provided by forcible upsetting of the material of the flange  145 C in a position to retain the first end  285  of the spring  290 . 
     The joystick cylindrical arm portion  310  is hollow, having a threaded internal recess  320 . A pair of openings  322 ,  325  pass transversely through the cylindrical arm portion  310  and the internal recess  320 . The threaded internal recess  320  is configured for receiving a connecting screw  330  ( FIG. 6A ). The cylindrical arm portion  310  further includes a pair of longitudinally spaced annular flanges  335 ,  340  adjacent at its distal end  345 . 
     A given latch mechanism  100  may be used with one or more devices for unlatching same. As shown for example in  FIG. 3 , the latch mechanism  100  is operable by a conventional power actuator  115 . As shown, the power actuator  115  is mounted in line with the latch mechanism  100  by a bracket  116  fixed to the tonneau cover  55  by nut and bolt units  117  (or by a bracket not shown carried by the latch mechanism  100 ). The power actuator  115  conventionally is electrically connected to a power source  120  (e.g. the vehicle battery not shown) and operated by a switch  125 . The switch  125  is conventionally capable of direct manual actuation or actuation by a conventional wireless remote control (not shown). The joystick  130  is connected to the power actuator  115  by a substantially rigid spring wire, push/pull connector, or “spring pull”,  135  ( FIG. 4 ). Due to the construction of the joystick  130 , displacement of the joystick  130  in any direction will actuate the latch mechanism  100 . Therefore, the joystick  130  need not be aligned with the latch mechanism  100  as shown. The power actuator  115  can be any type of mechanical or electrical actuator, or a hydraulic, magnetic, or pneumatic actuator. Furthermore, the actuator  115  need not be fixedly attached to the joystick  130 , but need only be positioned so as to displace the joystick  130  upon activation. 
     As shown in  FIG. 3A , the spring pull  135  grips the cylindrical arm portion  310  of the joystick  130  between the flanges  335 ,  340 . As a further example one or more conventional pullable release cables  350 ,  355  ( FIG. 3A ) can be received through the openings  322 ,  325 , and maintained therein by distal end plugs  360 ,  365  fixed thereon. As a further example, a similar release cable, or a push rod  370 , having an eye  371  ( FIG. 6A ) can be fixed to the joystick  130  by a screw  330 . 
     In some instances, it may be desirable to provide more than one latch mechanism in a single installation of (e.g. tonneau cover pickup truck bed as in  FIG. 1 ). For example, two could be located and spaced apart along the tailgate, or one might be provided on each side of the pickup truck bed. In such a dual installation, it may be desired to use a single powered or manual actuator to unlatch both latch mechanisms  100 . This can be done without any modification to the joysticks  130  of the dual latch mechanisms  100 . As seen for example in  FIG. 3A , two joysticks  130  are spaced apart and linked by the cable  350 ,) the left (in  FIG. 3A ) joystick  130  being connected through the wire member  135  to the power actuator  115  ( FIG. 3 ), and the other joystick being connected by a further cable  355  to another (e.g. manual) actuator of conventional type, not shown. In this way, actuation of one joystick  130  actuates the other so that both of the corresponding latch mechanisms  100  unlatch simultaneously. 
     Since axial pushing on the exposed end of the at rest joystick will also pivot the latch release member  205  and open the latch mechanism  100 , it is contemplated that screw  330  ( FIG. 6A ) may in some instances be substituted by a manually engageable push button, not shown, with the latch mechanism  100  being located so that such push button is reachable by a user either inside or outside the protected cavity (e.g. truck bed in  FIG. 1 ). 
     Operation 
     The latch mechanism  100  has a latched position ( FIGS. 3 and 10 ), e.g. for latching the tonneau cover  55  in its closed, dotted line position on the pickup truck  50 . 
     As shown in  FIG. 10 , the latch member  200  is held in a latched position against the bias of the spring  210  by the interference of the latch release member  205 , wherein the tail portion  255  of the latch member  200  is received within the catch  265  of the latch release member  205 . 
     Referring sequentially to  FIGS. 11A-11H , the latched latch mechanism  100  is unlatched by axially depressing or pivotally deflecting the joystick  130  from its rest (here vertical) position shown in  FIG. 11A . In this position, the latch member  200  is positioned such that the outer arm  245  of the C-shaped portion  235  appears perpendicular to the left end  196  of the housing  140 . The latch member  200  and the housing  140  thereby close the channel  198  and trap the pin  110  therein, such that the tonneaus cover (for example) is closed and latched. 
     The joystick  130  is then pivotally deflected e.g. by the power actuator  115  drawing on the spring pull  135 , by a manual actuator (not shown) pulling on a cable  350 ,  355 , or in any other convenient way. 
     In  FIG. 11B , the joystick  130  has been slightly pivotally deflected (to the right in  FIG. 11B , though to the left or into or out of the page, or even axial deflection upward into the housing  140  would serve as well), forceably rotating the latch release member  205  slightly counterclockwise without yet releasing the latch member  200 . The joystick flat circular base portion  300  is slightly tilted away from the inner surface  316  of the housing  140 , while the frusto-conical portion  305  of the joystick  130  rides in the aperture  315  in the housing  140 . 
     In  FIGS. 11C-11D , the joystick  130  is further deflected. The latch release member  205  is rotated further counterclockwise still without releasing the latch member  200 . 
     In  FIG. 11E , the joystick  130  is fully deflected so that the latch release member  205  has been rotated sufficiently counterclockwise to clear the tail portion  255  of the latch member  200 . The latch member  200  is now free to rotate counterclockwise under the biasing force of the spring  210 . 
     In  FIGS. 11F-11H , the latch member  200 , freed from latch release member  205 , sequentially rotates counterclockwise towards its unlatched position. In  FIG. 11H , the latch member  200  has rotated to its fully counterclockwise, fully open position. At any time in the  FIG. 11F-11H  sequence the joystick  130  can be released, so that the latch release member  205  is allowed to rotate clockwise under the bias of the spring  225 , to return both to their  FIG. 11A  rest position. As the latch member  200  rotates counterclockwise under the bias of its spring  210 , the inner arm  240  of latch member  200  effectively pushes the latch mechanism  100  and pin  110  away from each other. The user is thus free to open the tonneau cover  55  to its  FIG. 1  solid line position. 
     In the preferred embodiment shown, and as seen for example in  FIG. 10 , during actuation the joystick base portion  300  bears at diametrically opposed points on the housing flange  150 H and on the foot  272  of the latch release member  205  to define a driven lever arm. On the other hand, the free end of the joystick, as at a point between the flanges  335  and  340 , may be connected to an actuator (for example the power actuator  115  or one of the release cables  350 ,  355 , or the like). The distance, between that connection point on the free end of the joystick and the mentioned point on the joystick base  300  bearing on the housing flange  150 H, defines a driving lever arm. The ratio of these two lever arms (e.g. 2 to 1) defines the mechanical advantage provided by the joystick. 
     Similarly, the distances from the rotative center of the latch release lever  205  (the axis of swaged bushing  175 ) to the point of contact of the foot  272  with the joystick base  300  above mentioned and to the point of engagement of the step-like catch  265  with the portion  255  of the latch member  200 , define corresponding driving and driven lever arms of the latch release member  205 . For example in the embodiment shown, the ratio of such lever arms is approximately 2 to 1, the latch release member  205  thus providing a mechanical advantage of approximately 2 to 1. 
     Thus, the joystick and catch release member, taken together would, in this example, thus provide a combined mechanical advantage of approximately 4 to 1. 
     Moreover, the distances from the pivot axis of the latch member  200  (the central axis of its swaged bushing  180 ) to the point of contact of its tail portion  255  with the step-like catch  265  of the latch release member  205  and to the point of contact of the spring  210  with the shallow notch  215 , again defines driving and driven lever arms, which in the embodiment shown are the length ratio of about 3/2. 
     Thus, in this particular example, there is a total mechanical advantage of about 6 to 1 from the joystick free end to pin  110 . The  FIG. 1  tonneau cover  55  may have substantial weight. To release the latch mechanism  100  requires the tonneau cover mounted inner arm  240  to push downward on the pin  110  with sufficient force to cause the bushing  180  and housing  140  and bracket  105  to lift the tonneau cover  55  out of its normally closed, latched position shown in dotted line in  FIG. 1 . Thus, the latch member spring  210  has to be strong enough to forcibly pivot the latch lever  200 , from its  FIG. 11F  position through its  FIG. 11G  position and into its fully opened  FIG. 11H  position, to lift the heavy tonneau cover  55 . However, that same strong spring  210 , in the latch mechanism closed position of FIGS.  10  and  11 A strongly holds the tail portion  255  against the step-like catch  265 , so as to strongly resist the opening rotation of the latch release lever  205  above discussed as to  FIGS. 11B-11D . Again, the distance, from the point of contact of the tail portion  255  of the latch member  200  with the step-like catch  265  of the latch release member  205 , ( FIGS. 10 and 11A ) to the point of contact of the spring  210  with the edge of the spring  210  with the edge of the notch  215  in the latch member  200 , is here in the approximate ratio of 1 to 1. Accordingly, the combined mechanical advantage available to overcome the force of the spring  210  by actuation of the joystick  130  is hereabout 6 to 1. Accordingly, if a 40 pound force is required to lift the tonneau cover  55  to complete the laterally sequence from  FIG. 11F through 11H , only about ⅙ that force (e.g. 7 pounds) need be applied to the end of the free end of the joystick  130  to open the latch mechanism  100 . Accordingly, it becomes possible to actuate the joystick  130  by relatively low force means, for example a conventional low cost power actuator  115 , even with a relatively heavy tonneau cover, and without need for the user to attempt to assist the unlatching process by manually lifting the tonneau cover. In short, even a relatively heavy tonneau cover  55  will pop open as the end result of the unlatching process shown in the  FIG. 11A-11H  sequence. 
     Vehicle users will occasionally load their pickup beds high enough that the user must exert downward pressure on the tonneau cover  55  to enable the pin  110  and latch lever  200  to assume their  FIG. 10  latched positions. In that instance, after latching, the user stops pressing downward on the tonneau cover  55  and moves away to other activity, but the overweight load in the pickup bed is still pressing the tonneau cover upward away from the pickup truck bed, and hence urges the latch mechanism  100  upward with respect to the pin  110 , i.e. adding to the counterclockwise (in  FIG. 10 ) force of the spring  210  and hence pushing the tail portion  255  even harder against the step-like catch  265  to further resist counterclockwise, unlatching rotation of the latch release member  205 . Thus, the substantial mechanical advantage provided by the inventive joystick  130  and latch release  205  allows this added resistance to latching to be overcome with a relatively light force applied to the joystick  130  manually, by cables, or by the power actuator  115 . 
     The power actuator  115  and other means (e.g. cables  350 / 365  of  FIG. 3B  actuate the joystick independently of each other, i.e. the power actuator actuates the joystick when the cables are slack and the cables actuate the joystick when the actuator is not powered. The latch mechanism  100  can be initially installed without the power actuator and, at some later time, the user can add a power actuator. 
     Should a person accidentally become trapped in the  FIG. 1  pickup truck bed with the tonneau cover  55  latch closed, the inventive latch mechanism  100  provides a safety advantage in that it enables relatively easy escape. More particularly, the joystick  130  stands proud from the housing  140  to a substantial extent and so is relatively easy to find, even in the dark. Also, the joystick  130  requires only a very low activating force (in view of the substantial mechanical advantage of the latch mechanism  100 ), and pushing or pulling the joystick in a wide range of directions causes the latch mechanism  100  to unlatch. 
     The joystick  130  is free to rotate about its length (vertical in  FIGS. 6 and 6A ) axis to orient the diametral through holes  322  and  325  in any desired direction on a plane perpendicular to the longitudinal axis of the joystick, so as to accommodate the actuators (e.g. cables  350  and/or  355  ( FIG. 3B )) approaching the joystick from virtually any direction. 
     While the invention has been described in the specification and illustrated in the drawings with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined in the claims. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to particular embodiments illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the invention will include any embodiments falling within the scope of the appended claims.