Linkage for vehicle door latch
TECHNICAL FIELD 
     This invention relates to vehicle door latches for releasably securing a hinged door in the door frame provided in the vehicle body work, and more particularly, to a new door latch. 
     BACKGROUND OF THE INVENTION 
     Prior to the present invention, various door latches have been devised for selective securement of a hinged vehicle door in the frame therefor as provided by the body work of the vehicle. Examples of such latches can be found in U.S. Pat. No. 3,695,663, issued Oct. 3, 1973, to Stanley Cockburn for &#34;CLOSURE LATCH&#34;, and in U.S. Pat. No. 4,756,563, issued Jul. 12, 1988, to Stephen Garwood et al for &#34;VEHICLE DOOR LATCH&#34; both assigned to the assignee of this invention and hereby incorporated by reference. 
     These latches and other latches commonly used in motor vehicles are known to effectively latch the door and comply with all applicable governmental regulations. 
     The present invention is of the general category of the above referenced door latches which securely holds the door in latched and locked positions and allows convenient entrance and egress as desired by vehicle passengers. 
     The present invention provides a new blockout that may be engineered into a wide range of door latching systems. Furthermore, this invention incorporates construction to effectively return the mechanism to an unblocking position by the normal unlocking motion of a locking-unlocking mechanism incorporated within the door to an unblocking third position allowing convenient and easy egress when desired. In this invention, the locking lever of the door latch is selectively movable by a garnish button or manual or powered slide bar to a first or locked position in which the striker is entrapped by the locking bolt so that the locking lever cannot turn the lock bolt to the unlatched position until the door locking-unlocking lever system has been moved by the slide bar from the locked position to a second or unlocked position. 
     Importantly in this invention, the locking lever can be readily moved to a third position by the slide bar in which a block activated blocker bar is moved to an unblocked position. The third position is obtained by the moving of the locking-unlocking lever system in the conventional unlocking direction to the unblocked position so that the door can be opened for passenger egress. The block will blockout unlatching of the door in both lock and unlock positions by resulting tilting of a blocker bar moving the locking lever to a third position in direction of unlocking will remove the blocking by the blocker bar. 
     Furthermore in this invention, a pair of lever mechanisms interface (1) the inside door unlatching handle linkage, and (2) the locking lever system that may be actuated by the interior manual or powered slide bar, or garnish button to move the locking lever in the locked or unlocked position. These lever mechanisms cooperate to retain the locking lever in an unblocked position and to subsequently remove this retention on the return of the inside handle to its normal stowed position. 
     The present invention is designed to be housed within the existing structure of the door and automatically locks the door latch independently of the locking lever and incorporates an unblocking system that can be readily operated with one hand using normal unlocking force. The system is self restoring with each activation of the inside handle and is a straight forward system that can be economically produced. 
     These and other features, objects and advantages of this invention will become more apparent from the following detailed description and drawing in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of a portion of a vehicle with door paneling structure partly removed showing one location of the door latch assembly and associated control linkage illustrative of this invention; 
     FIG. 2 is an enlarged side elevational view of the door latch assembly and control linkage of FIG. 1 with some parts removed and with parts broken away; 
     FIG. 3 is a diagrammatic view of the vehicle door latch assembly of FIG. 2 to illustrate one preferred embodiment of this invention; 
     FIG. 4 is a side elevational view similar to that of FIG. 2 illustrating the latch assembly and control linkage in a moved position; 
     FIG. 5 is a view of a portion of FIG. 2 showing the control linkage thereof in a moved position; 
     FIG. 6 is a top view of the control linkage of FIG. 5 taken generally along sight lines 6--6 of FIG. 5; 
     FIG. 7 is a view generally similar to that of FIG. 5 showing the linkage thereof moved to another position; 
     FIG. 8 is an enlarged view of a portion of the latching system of this invention; 
     FIG. 9 is a view similar to that of FIG. 8 showing additional components of the latching system and the latching system in a locked condition; and 
     FIG. 10 is a pictorial view of the blocking bar of the locking system as viewed in the direction of sight arrow A of FIG. 8. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Turning now in greater detail to the drawings, a motor vehicle designated generally at 10 includes a front door 12 conventionally hinged at its forward side 14 to the front pillar of the door opening in the body 16 of the vehicle for swinging movement between open and closed positions to allow passenger entrance and egress. A door latch assembly 18 including a thick plastic main body 20, having an outboard side a metal plate 21, is secured to rearward supporting structure 22 of the vehicle door. A locking bolt 24 is pivotally mounted within the main body 20 for selective retentive engagement with a conventional striker pin 26 operatively secured to the rearward pillar of the door opening to selectively retain the door in a closed position. 
     As shown in FIG. 3, the locking bolt 24 is a flat, generally circular member which is bifurcated to have a fork or throat 28 for receiving the striker pin 26, which enters therein through an enlarged mouth 27 in the main body and a laterally extending slot 29 in the plate 21. The locking bolt 24 is mounted by pivot 30 to the main body of the latch assembly for turning movement between latched and unlatched positions in which the fork of the bolt is closed around the striker pin 26 (FIGS. 2 and 3) and an open position in which the fork or throat of the bolt is aligned with the mouth 27 of the main body to receive or release the striker pin (FIG. 4). The locking bolt 24 can be selectively turned to the unlatched position by interior and exterior pull handles 32 and 34 that are operatively connected to the bolt 24 by a system of interacting levers diagrammatically illustrated in FIG. 3, and generally similar to the lever system disclosed in the above referenced U.S. Pat. No. 4,756,563 to Garwood et al. 
     FIGS. 2 and 4 best illustrate the inside pull handle 32 mounted on a pivot shaft 36 secured to vertically spaced and projecting ears 38 of a bracket 40 mounted by threaded fasteners to an inner panel 41 of the door. A torsion spring 42 extending around the shaft 36 and has one end grounded to the bracket 40 and the other end 43 connected to an offset lever portion 44 of the handle 32 to exert a spring force thereon to bias the handle to a closed position after its manual release. 
     The offset lever portion 44 of the handle is pivotally connected to the upstanding end 46 of an elongated inside release handle rod 48 that extends longitudinally within the door and is slidably mounted therein through guides 50 secured to the door panel 41. As shown, the release rod 48 terminates in a pivot connection 52 to an extending arm of a flat inside operating or remote lever 54 that is mounted for limited pivotal motion by pivot 56 supported by a bent-over flange 58 of the metal side plate 21. 
     By pulling the handle 32 outwardly so that it turns on its pivot shaft 36 against the force of spring 42, the rod 48 will be pulled toward the handle 32 causing remote lever 54 to be turned clockwise from the FIG. 2 to the FIG. 4 position. This action results in the engagement of projecting actuator finger 60 of remote lever 54 with an extending contact arm 62 of a transfer lever 64, best shown in FIG. 3, to urge lever 64 to turn clockwise, arrow B, on pivot 68 mounted to a metal side plate 69 secured to the other side of main body 20. The main body 20 of the latch assembly is sandwiched between the side plates 21 and 69. 
     As shown best in FIG. 3, the transfer lever 64 has an extending upper actuator arm 70 that when turned in the clockwise direction engages an extending tab 72 of an intermittent lever 74 when the lever is in the phantom line position. As the transfer lever 64 continues its clockwise turning movement, the intermittent lever 74 will be pulled downwardly by the actuator arm. The intermittent lever 74 is attached by a pivot pin 76 to a detent lever 78 which is pivoted in the main body 20 by pivot 80. 
     On the downward movement of the intermittent lever, the detent lever 78 resultantly turns in a clockwise direction, arrow D, and the detent lever blocking shoulder 82 will move from contact with the stop surface 84 on the inboard leg of the lock bolt throat 28 which receives the striker pin 26. When this happens, a helical tension spring 88 which has been stretched on the closure of the door 12, contracts to turn the lock bolt 24 clockwise, arrow F, so that the throat 28 is turned to an opened position shown in FIG. 4 to allow the door to be swung outwardly for passenger egress or for passenger entrance. 
     On return of the door to the closed position, the striker pin 26 will engage the inboard surface of the leg of the throat 28 of the locking bolt to rotate the locking bolt counterclockwise back to the FIG. 3 position and again stretch spring 88. Torsion spring 85 biases the detent lever to the latching position against stop 90, as shown in FIG. 3. Other springs of this lever system, are not shown to simplify the drawing but their constructions and operations are substantially the same as disclosed in U.S. Pat. No. 4,756,563 to Garwood et al. 
     In addition to the latching and unlatching provided by this invention, there is further incorporated a locking linkage 94 that can be employed to secure the door 12 in a latched and locked condition, a latched and unlocked condition and in an unblocked position. To this end, there is an interior manual or powered slide bar 96 mounted in a recessed support bracket 97 and movable between (1) a locking position 98 in which the locking bolt throat is held in the latched and locked position and cannot be turned by the pull handles, and (2) an unlocked position 100 in which the throat of the locking bolt can be, or is, turned to the opened position by operation of the interior or exterior pull handles and their associated linkages, and (3) to an unblocked position 102 which will be described below. 
     As best shown in FIGS. 2 and 4, the interior slide bar 96 is fixed at its inner end to the end of an elongated lock control rod 104 that is slidably mounted relative to the interior panel 41 by retainers and guides 106. The rod 104 terminates in a pivot connection 108 with an elongated arm 110 of an inside lock control lever 112 that is pivoted by pivot 114 to the flange 58 of the door latch assembly. When the slide bar is linearly moved from the unlocked position 100 to the locked position 98, the lock control lever 112 will be turned on pivot 114 in a clockwise direction with particular reference to FIG. 2. On this turning movement, a finger 116 of the lock control lever 112 engaged in a recess 118 in a locking lever 122 engages an upper contact surface 120 thereof to turn the locking lever 122 in a clockwise direction on pivot 68. 
     A follower pin 124 projecting from the intermittent lever 74 that fits within a camming slot 126 formed in the locking lever 122, follows the movement of the camming slot to turn the intermittent lever 74 to the full line position of FIG. 3, in which the contact tab 72 is correspondingly moved to an out-of-way or lock position with respect to the actuator arm 70 of the transfer lever 64. In this &#34;lock&#34; position, the actuator arm 70 &#34;free wheels&#34; past the tab 72 of the transfer lever so that the detent lever and the locking bolt remain in the locked position. Accordingly, with the slide 96 in the locked position, the inside or outside handle cannot be pulled to open the door 12 until the locking linkage 94 is returned to the latched but unlocked position of FIGS. 2 and 3, or to the unblocked position which will be described. 
     The outside handle 34 is operatively connected to a control lever 130 shown in FIG. 9 which is connected to the transfer lever 64 of the latch assembly by a linkage system, not shown, so that when the locking linkage 94 is in a latched but unlocked condition (FIG. 2), the locking bolt 24 can be turned by the handle 34 to the opened position allowing the door to be moved from the closed position for passenger entrance. Similarly, a lever system, not shown, is connected to an outside door key cylinder 132 to the key cylinder lever 133, which is operatively connected to the locking lever 122 and to the intermittent lever 74 to move the tab 72 between the &#34;freewheel&#34; locking position and the latched and unlocking position, thereby allowing the lock cylinder to be turned by the key to lock and unlock the door. These linkages are described in the above referenced U.S. Pat. No. 4,756,563 to Garwood et al so that further detailed description is not necessary for these components. 
     In this invention, a sensing block is provided for a door latching system such as described above. In a preferred embodiment, the vehicle door latch assembly 18 is provided with inverted or standing block which will cause the unlatching capability of the latch assembly to be blocked and thereby locked even though the locking linkage 94 is in a latched but unlocked condition, FIG. 2, when the vehicle and block are subject to a predetermined stimulus. 
     As shown in the preferred embodiment, a standing block 140 is operatively mounted in a cage 142 which is secured between the laterally spaced side plates 21 and 69 at the lower end of the door latch assembly 18. The standing block 140 has its mass centered at 146 and the enlarged conical head portion extends upward from a cylindrical support pedestal or foot 148 that is supported on the inner surface 150 of the cage 142. 
     The cage 142 has a cylindrical wall 152, which is suitably spaced from the head of the block when in upright position so that the block can tilt from a standing position to an inclined position when subjected to an unbalancing force of predetermined magnitude or greater. The block is formed with a conical camming recess 156 in the upper surface thereof which receives the partly spherical follower 158 depending from a flat rectilinear blocker bar or plate 160. 
     The blocker bar 160 has a pair of pivot tabs 162 extending from opposite side edges thereof that pivotally fit into retainer portions 164 of the upwardly extending and laterally spaced arms 165 of cage 142 so that the blocker bar 160 can pivot on its pivot tabs 162 from a horizontal position in which a lower and downwardly extending arm portion 166 of the transfer lever 64 can turn or free wheel past the blocking bar to an inclined or tilted position, see FIG. 9, in which the blocker bar limits the unlatching movement of the transfer lever 64 so that it cannot turn any further and the associated intermittent and detent levers are immobilized and the striker pin will remain captured by the locking bolt. The blocker bar also has another pair of tabs 167 which extend through the wedge shaped cut outs 169 in the side plates which can contact the interfacing edges thereof to limit blocker bar rotation. 
     The lower end of the transfer lever 64 is formed with an offset tooth 172 that has a radial contact surface 174 that is engagable with a forward edge 176 of the blocker bar when the blocker bar has been tilted by the movement of the block 140, as shown in FIGS. 8 and 9. Accordingly, the block tilts so that the transfer lever 64 is blocked and the door will be held in a locked condition until the block returns to an upstanding position. 
     In the event the block and blocker bar remain in tilted positions such as might occur if the vehicle is on a sharply inclined surface, the door 12 can be opened by the manual linear movement of the slide bar 96 to the right in a natural unlocking movement until the manual overriding and unblocking position 102 is reached, as shown in FIG. 4. 
     When the slide bar 96 is displaced to the unblocking position 102, the lock control rod 104 will turn the locking control lever 112 clockwise on pivot 114. This action causes the finger 116 of the lock control lever to contact surface 180 (FIG. 3) on the locking lever 122 causing it to rotate counterclockwise. The locking lever 122 has a depending arm 184 with a lower control surface that sweeps across the upper surface of the blocker bar 160 to contact the upper surface of an inclined ramp 186 which is affixed to the top of the blocker bar. As the depending arm 184 reaches the top of the inclined surface provided by the ramp 186, the blocker bar will be pivoted on its pivot tabs 162 to a flat or an unblocking position and the block forced to an upright position in its cage. 
     In this position of the blocker bar, the door handles can be pulled to their open position effecting rotation of the transfer lever 64 past the blocker bar. When this occurs, the intermittent lever will be moved to effect rotation of the detent lever and the locking bolt will be biased by its spring 88 to an unlocked position. As shown in the pictorial view, FIG. 10, the inclined ramp 186 is offset with relation to the transfer lever 64 so that there is no interference between the transfer lever and the inclined ramp. 
     When the slide bar 96 has been moved to the manual overriding and unblocking position 102, a control leg 190 of the generally U-shaped and laterally offset segment 191 of the rod 104 engages the inclined forward edge 193 of the offset hooked end 192 of a J-shaped holding lever 194. The movement of the rod 104 to the FIG. 4 position causes the lever 194 to turn counterclockwise on pivot 196 extending from the door panel 41 against the action of a return torsion spring 198, which is coiled about the pivot 196 and has one end 200 grounded on a fixed tab 202 extending from the support within the door, and the other end 206 hooked around an extending retainer portion 208 projecting at right angles from the top of the leg of the J-shaped holding lever 194. 
     When the contact leg 190 of the rod 104 engages the hooked end 192 of the holding lever 194, the holding lever is turned counterclockwise until the leg 190 passes over the hooked end of the holding lever. 
     Subsequently, the holding lever 194 under the action of the torsion spring 198 quickly returns the holding lever to the position shown in FIG. 4 to thereby trap the lock control rod 104 in the unblocked position in which the depending arm 184 holds the blocker bar 160 in a release position allowing the inside door handle to be pulled and the door to be opened. 
     Helical spring 212 coiled around rod 104 seats against the rod guide 106 and biases against a retainer 213 affixed to the rod to urge the rod 104 to the left in the Figures so that the outer surface 214 of the leg 190 contacts the inner surface of the hooked end of the holding lever. The holding lever cannot turn in the clockwise direction from the FIG. 4 position since the leg thereof contacts tab 202. Accordingly, the holding lever holds the rod in the unblocked position shown in FIG. 4. The door handle 32 can then be pulled to pull the release handle rod 48 and through the lever system described to move the locking bolt to the open position allowing the door to be opened. 
     After the door handle 32 is released, the door handle linkage rod has disengaging construction that will automatically effect the release of the unblocking function provided by the J-shaped holding lever 194 and its holding contact with the outer surface of leg 190 of the U-shaped offset segment 191. 
     To this end, when the operator releases the inside handle 32, the torsion spring 42 will turn the handle to its closed position and the linkage rod 48 will travel toward the latch assembly which causes a disengaging lever 220 mounted on rod 48 to remove the unblocking feature, as illustrated in FIG. 7. 
     The disengaging lever 220, is in elevational view, a generally V-shaped element having a head portion 222 at one arm end that forms a fork 224 providing a recess which receives one leg 226 of a U-shaped offset portion 228 of the inside release handle rod. The recess of the fork provides a pivot for the disengaging lever so that it can pivot on the leg 226 of the offset of rod 48. The other end of the disengaging lever has a head portion 230 which is arched to provide a recess to fit on top of the rod 48. A torsion spring 234 has a coiled body wound on the leg 226 of the rod offset and between the arms of the fork and a first arm 240 that is bent to ground on the top of the other leg 241 of the offset portion 228. The second arm 242 of spring 234 has an end bent at right angles into a recess formed transversely in the arched head portion 230 of the disengaging lever. With this construction, the disengaging lever 220 will be spring biased in a counterclockwise direction with the arched head 230 limiting this movement. 
     When the handle 32 is initially pulled from the FIG. 2 to the FIG. 4 position to open the door, the edge 245 of the disengaging lever will strike the retainer portion or arm 208 of the holding lever so that the disengaging lever 220 will turn clockwise on its pivot fork against the action of helical spring 234 and move upward as the rod 48 moves from the FIG. 2 to the FIG. 4 position. In the position of FIG. 4 the disengaging lever is in a seated position and ready to effect disengagement of the holding lever. 
     Accordingly, when the pull handle 32 is released, it returns to the stowed position under action of the spring 42 and this action strokes the release handle rod 48 in a linear direction toward the latch assembly. The outside camming surface 248 of the disengaging lever 220 will contact the extending retainer portion 208 of the holding lever 194 causing the holding lever 194 to pivot in a counterclockwise direction. When the holding lever is pivoted to its release position of FIG. 7, the lock control rod 104 and connected components are moved by the force of compressed spring 212 to the unlocked position shown in FIG. 2. 
     Accordingly, the two lever mechanisms 194 and 220 interface the inside handle linkage system and the locking slide linkage system to releasably hold the locking levers in an unblocked position and to automatically remove the holding feature on the return of the inside handle to its normal spring biased stowed position, shown in FIG. 2. This construction is a reliable mechanical system which allows the single handed door release operation when locked by the block and is self restoring to a normal unlocked position with release of the inside pull handle. 
     While a preferred embodiment of the invention has been shown and described, other embodiments will now become apparent to those skilled in the art. Accordingly, this invention is not to be limited to that which is shown and described but by the following claims.