Abstract:
A power latch system is employed for securing a convertible roof to an automotive vehicle body. In another aspect of the present invention, a striker is movably mounted to either a forward or rearward portion of a convertible roof which is operably engaged by an automatically powered latch mounted to the vehicle body. Still another aspect of the present invention employs a rotatable latch having a striker engaging slot internally projecting from a periphery.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     The present invention relates generally to convertible roofs for automotive vehicles and more particularly to a power latch used with an automotive vehicle convertible roof. 
     It is common to employ manually operated or electrically powered latches to secure a number one roof bow of a convertible roof to a front header panel of an automotive vehicle body. Many conventional convertible roof latches employ a hook-like member which projects from beyond the front header or number one bow for engaging a striker. One such example is disclosed in U.S. Pat. No. 5,624,149, entitled “Apparatus and Method for Securing a Convertible Roof to an Automotive Vehicle” which issued to Tokarz on Apr. 29, 1997; this patent is incorporated by reference herein. Other latches are known which rotate about a moving pivot which is disposed on an opposite end of the latch from the striker engaging hook. This construction is shown in U.S. Pat. No. 5,269,586, entitled “Device for Lowering the Free End of a Vehicle Cover” which issued to Hahn et al. However, many traditional latches suffer from extremely confined packaging space. This often causes awkward and remote positioning of the power actuator relative to the latch. Furthermore, many of the striker engaging hooks are unable to maximize the mechanical advantage of the device and instead, project in an offset manner from the pivot axis and from the driving linkage connection. 
     In accordance with the present invention, a preferred embodiment of a power latching system is employed for securing a convertible roof to an automotive vehicle body. In another aspect of the present invention, a striker is movably mounted to either a forward or rearward portion of a convertible roof which is operably engaged by an automatically powered latch mounted to the vehicle body. A further aspect of the present invention allows for the automatically powered latch to be mounted to the convertible roof while the striker is mounted to the body. Still another aspect of the present invention employs a rotatable latch having a striker engaging slot internally projecting from a generally circular periphery wherein the latch is operably rotated by an electromagnetic device. In yet another aspect of the present invention, a rotatable latch traps a striker within an internal latch housing receptacle. Another aspect of the present invention serves to rotate the portion of the striker engaged with the latch to an over center position beyond the latch&#39;s pivot axis. A power latch of the present invention acts to secure a rearmost portion of a convertible roof against a movable tailgate of an automotive vehicle in another aspect of the present invention. 
     The power latch of the present invention is advantageous over traditional latches in that the present invention employs a geometrically balanced striker engaging member which efficiently uses the mechanical advantage of the system. It is also advantageous that a majority, if not all, of the latch movement occurs within a protective housing and within the vehicle body to which it is mounted; this provides an aesthetically pleasing appearance when the roof is retracted. The power latch of the present invention is ideally suited for use with a convertible roof that is downwardly collapsible against a movable tailgate or upwardly against a rear header panel; for example, the power latch can be placed in previously unused packaging space without the need for remote cables or connecting rods, and the associated expense and routing difficulties associated with such conventional constructions. Additional advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary perspective view showing the preferred embodiment of an automotive vehicle convertible roof system of the present invention with front and rear convertible roofs disposed in closed and fully latched positions; 
     FIG. 2 is a fragmentary perspective view showing the preferred embodiment automotive vehicle convertible roof system with the convertible roofs disposed in rearward open positions; 
     FIG. 3 is a fragmentary perspective view showing the preferred embodiment automotive vehicle convertible roof system with the rear convertible roof disposed in a partially forward open position and with a tailgate disposed in a partially open position; 
     FIG. 4 is a fragmentary side elevational view showing a power latching system employed in the preferred embodiment automotive vehicle convertible roof system; 
     FIG. 5 is an exploded perspective view showing the power latching system employed in the preferred embodiment automotive vehicle convertible roof system; 
     FIG. 6 is a perspective view, taken opposite that of FIGS. 4 and 5, showing the power latching system employed in the preferred embodiment automotive vehicle convertible roof system; 
     FIG. 7 is a perspective view, like that of FIG. 5, showing the power latching system employed in the preferred embodiment automotive vehicle convertible roof system; 
     FIG. 8 is a side elevational view, like that of FIG. 4, showing the power latching system employed in the preferred embodiment automotive vehicle convertible roof system, disposed in unlatched position; and 
     FIG. 9 is a side elevational view, similar to that of FIG. 8, showing the power latching system employed in the preferred embodiment automotive vehicle convertible roof system, disposed in a fully latched position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1-4, the preferred embodiment of an automotive vehicle convertible roof system  21  employs a plurality of power latching systems  23  to secure a rear convertible roof  25  to a body  27  of an automotive vehicle. Rear convertible roof  25  employs a fabric top spanning between a plurality of roof bows. A backlite  29  and side windows  31  are secured to the fabric top. A set of actuating balance links  33  and pneumatic cylinders  35  are used to raise and lower rear convertible roof  25  in a manual manner. Alternately, an electric motor actuator or hydraulic actuated linkage mechanism can be employed to automatically open and close rear convertible roof  25 . 
     In the preferred embodiment, rear convertible roof  25  is rearwardly retractable from the closed position of FIG. 1 to the open position of FIG.  2 . Rear convertible roof  25  may also be opened in a forward and upward manner as is shown in FIG.  3 . When closed, a rearmost roof bow  41  rests against an upper edge  43  of a body panel, such as a door or tailgate  45 . Rearmost roof bow  41  and the adjacent portion of rear convertible roof  25  are upwardly movable, as shown in FIG. 3, to allow access to the rear storage area of the vehicle and also to allow downward pivoting of tailgate  45 . One such rear convertible roof construction is disclosed in U.S. Pat. No. 5,775,767 entitled “Convertible Top for a Vehicle having a Rear Egress” which issued to Harrison et al. on Jul. 7, 1998, and is incorporated by reference herein. A weatherstrip  60  is mounted to rearmost roof bow  41 . 
     A front convertible roof  61  is also provided over the front passenger seating area. Front convertible roof  61  includes a fabric cover spanning between a plurality of roof bows. Front convertible roof  61  closes to a generally horizontal position as shown in FIG.  1 . FIG. 2 illustrates front convertible roof  61  open by rearwardly sliding the roof bows and attached fabric in an overlapping folded manner. Power latching system  23  is preferably employed to operably secure rearmost roof bow  41  to a body portion of the vehicle adjacent tailgate  45 . Alternately, however, such a power latching system can be used to secure a forwardmost roof bow  63  (see FIG. 2) to a rear header panel  65  or to secure a roof bow of front convertible roof  61  to a front header panel  67  or to rear header panel  65 . 
     Referring to FIGS. 4-9, the preferred embodiment of each power latching system  23  includes a striker assembly  81  and a latch assembly  83 . Striker assembly  81  has a U-shaped striker  85  pivotably mounted to a base  87 . A torsion spring  89  is wound around a pair of transversely extending legs  91  of striker  85  and serves to bias striker  85  in an extended position with the central transverse section furthest away from base  87 . This striker-to-roof bow pivoting action allows for tolerance mismatches or bow flexibility between each side of the vehicle when rear convertible roof  25  is being engaged or disengaged to body  27 . Base  87  is screwed into roof bow  41 . 
     Latch assembly  83  includes a fractional horsepower, direct current electric motor  101 , a worm segment  103  of a rotating armature shaft  105 , a cover plate  107 , a cam plate  109 , a housing  111  and a latch  113 . A bearing  115  is positioned around a middle segment of armature shaft  105  for mounting to housing  111 , and a plurality of annular bushings  117  are positioned between cover plate  107 , cam plate  109 , latch  113  and housing  111 . An electric limit switch  119  is also attached to housing  111  and electrically connected to an electric control unit (not shown), such as a microprocessor, which controls energization of electric motor  101  and an automatic top stack actuation mechanism, if employed. A close-out plate  121  is preferably produced as a single part with the hidden portion of housing  111 , but may alternately, be produced as a separate member. Housing  111  is screwed onto the rear quarter panels of body  27  immediately adjacent tailgate  45  (see FIG.  3 ). Alternately, each latch assembly  83  may be mounted within the tailgate  45  itself. Each latch assembly  83  is mechanically independent from each other whereby traditionally difficult to package interconnecting linkages and cables are not required with the preferred embodiment of the present invention. Thus, each latching assembly has its own motor  101  and latch  113 . 
     Housing  111  has an arcuately shaped internal path  131  which defines a dead end surface. This surface is stationary relative to the corresponding portion of the vehicle body  27  (see FIG.  4 ). An exposed access hole  133  of plate  121  allows insertion of striker  85  into path  131 . 
     Latch  113  is rotatable about a pivot pin  135  which rotates within pivot holes  137  of housing  111  and cover plate  107 . Latch  113  has a generally circular periphery with worm gear teeth  139  outwardly projecting from the circular periphery. A finger  141  radially projects in an outward manner from the periphery of latch  113  and a striker-receiving slot  143  inwardly projects in a radial direction adjacent finger  141  and toward pivot pin  135 . A tab  151  also outwardly projects from the periphery of latch  113 . An arm  153  affixed to housing  111  abuts against a radial surface of tab  151  to limit rotation of latch  113  to the position shown in FIGS. 7 and 8. This defines the fully unlatched orientation. 
     When striker  85  is inserted through hole  133  of housing  111 , striker enters path  131 , abuts against finger  141  and then engages within slot  143  of latch  113 . This causes depression of limit switch  119  which will energize electric motors  101  on both sides of the vehicle. Energization of each electric motor  101  causes armature shaft  105  and worm gear segment  103  to rotate. This action, in turn, drivably rotates latch  113  approximately 150 degrees to the fully latched position shown in FIG. 9, at which point the electric motor  101  is deenergized. In the fully latched position the central portion of striker  85  is trapped between an end surface of the housing path  131  and slot  143  of latch  113 . It is noteworthy that pivot pin  135  is fixed, with the exception of rotation, relative to housing  111  and the adjacent vehicle body. This serves to simplify the mechanical motion and leverage of the latch in a small package space and with a smaller than normal electric motor. 
     Cam plate  109  assists in releasing striker  85  from latch  113  upon reverse rotation of armature shaft  105 , worm gear segment  103  and latch  113  during striker unlatching. Cam plate  109  only rotates in a unidirectional manner during insertion of striker for the latching motion. Cam plate  109  rotates in 120 degree intervals when latch  113  is rotated from the unlatched position to the fully latched position. Insertion of striker  85  causes the intermittent rotation of cam plate  109  between the camming orientations. Arm  153  is mounted to housing  111  in a spring biased manner and abuts against peripheral projections  171  of cam plate  109  to prevent reverse rotation. The three peripheral camming surfaces  173  are angled to push striker  85  out of slot  143  of latch  113  when latch  113  is rotated from the fully latched position to the unlatched position. The spring biased arm  153  assists in this cam plate pushing motion. 
     A plurality of micro switches can also be employed to sense the relative positioning of the forwardmost rear bow of the rear convertible roof relative to the rear header and to sense the rearmost roof bow relationship to the quarter panels or tailgate. These micro switches are operable to sense the fully open, fully closed, latched and unlatched positions of the convertible roof for selective energization of the actuation mechanism by the electric control unit. 
     While the preferred embodiment of a power latch for an automotive vehicle convertible roof system has been disclosed, it will be appreciated that various other embodiments may be employed within the scope of the present invention. For example, the latch and electric motor can be mounted to the convertible roof bow and the striker can be mounted to the body panel. Furthermore, other latch and striker configurations can be employed although the advantages of the disclosed present invention may not necessarily be achieved. Additional gears may also be provided between the motor and the latch. While various materials and shapes have been disclosed, it will be appreciated that a variety of other materials and shapes may be employed. It is intended by the following claims to cover these and any other departures from the disclosed embodiments which fall within the true spirit of this invention.