Field of Search:
292/210,45,48,216,280,DIG.26,DIG.27,DIG.49,DIG.65
Claims:
I claim
1. A latch mechanism comprising:
2. A latch device mechanism according to claim 1, in which:
3. A latch mechanism according to claim 2, in which:
4. A latch mechanism according to claim 3, in which:
5. A latch mechanism according to claim 4, in which:
6. A latch mechanism according to claim 2, in which:
7. A latch element according to claim 6, in which:
Description:
BACKGROUND OF THE INVENTION
The conventional vehicle door latch mechanism comprises an assembly of pivoted latch elements, pivoted detent means for holding the latch elements in latched condition, pivoted levers for actuating the detent means to disengage the latter from the latch elements to permit unlatching movement and various springs to bias the various pivoted members in the relative directions of movement required to achieve the desired functions. The detent means in particular is spring-urged in latch element engaging direction.
For any one of a number of reasons, the spring acting on the detent means may fail to bias the latter back into holding position relative to the latch elements after disengagement therefrom. For example, the spring itself may fail, a corrosion buildup between the detent means and support plate may create excessive friction which the spring is unable to overcome or an ice coating between the detent means and support plate could interfere with proper operation.
Accordingly, it is an object of the present invention to provide a latch mechanism incorporating a latch element movement responsive means for positively driving the detent means into latch element holding position upon movement of the latch elements to latched position.
SUMMARY OF THE INVENTION
The present invention relates to a latch mechanism comprising a primary support plate for disposition on the inner surface free edge wall of a vehicle door. The latch mechanism has a secondary support plate in spaced parallel relation to the primary support plate. Mounted on the side of the primary support plate facing the secondary support plate is a latch device means comprising a pair of latch elements each mounted on a respective pivot shaft for counterswinging movement into and out of latched position. A detent means comprising a lever member having a plurality of lever arms is pivotally mounted on a primary support plate on the same side of the latter as the latch device means. The detent means has an arm having spaced detent portions adapted to simultaneously engage spaced abutments on the latch device elements to hold the latter against counterswinging movement from latched to unlatched position. A spring means engaged with the detent means normally urges the latter toward latch element holding position. The latch mechanism includes a cam means responsive to movement of the latch device means toward latched position, as occurs upon engagement of the latch elements with a striker as the door is moved to closed position. This cam means positively biases the detent means into latched element holding position if the spring means fails to do so.
In particular, the cam means comprises a cam surface on a second lever arm of the detent means. The cam surface underlies the peripheral surface on one of the latch elements. The one latch element has an abutment positioned to engage the cam surface to drive the detent means into latch element holding position.
The latch mechanism also has various members for actuating the detent means to disengage the latter from the latch elements and also to render at least the outside operator inoperative to release the detent means.
DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present invention will be explained in greater detail making reference to the description which now follows, reference being had to the drawings in which:
FIG. 1 is a fragmentary perspective view of a vehicle body and a vehicle door, parts of the door being cut away to expose the latch mechanism;
FIG. 2 is a plan view of the latch mechanism with a major portion of the cover plate or secondary support plate cut away to expose the latch mechanism components;
FIG. 3 is a plan view in part sectional of the primary support plate of the latch mechanism with the latch mechanism components mounted thereon shown in unlatched condition;
FIG. 4 is a plan view of the inner side of the cover plate or secondary support plate with the components of the latch mechanism mounted thereon;
FIG. 5 is a diagrammatic view of the latch elements and the detent means as they appear when the latch mechanism is in a secondary latched condition;
FIG. 6 is a view in part similar to FIG. 5 illustrating the latch elements and the detent means in fully latched condition; and
FIG. 7 is a view in part similar to FIG. 5 illustrating the latch elements in unlatched condition and the detent means as it appears after being actuated for disengagement from the latch elements but before it is biased toward and restored in latch element engaged position by the spring means acting thereon.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, the latch mechanism, generally designated 10, is adapted to be mounted within a vehicle door 11 of a vehicle body. The latch mechanism is adapted to engage a striker pin 12 carried on the jamb face 13 of a vehicle body panel 14.
The latch mechanism 10 has a primary support plate 15 which is adapted to be secured by bolts (not shown) to the inner surface of the free edge wall 16 of the door 11. Threaded bolt receiving holes 17 are visible in the FIG. 3 view of the primary support plate 15. The latch mechanism has a secondary support plate 18 which is in spaced parallel relation to the primary support plate 15. The two plates 15 and 18 are held in spaced parallel relationship to each other by side flanges 19 and 21 on the plate 15 and a top flange 22 on the plate 18.
The operating components of the latch mechanism are located between the primary and secondary support plates 15 and 18. Some of these components may be considered as primarily mounted on the inner side of the primary support plate 15. These include the latch device means which comprises a pair of latch elements 23 and 24. The latch elements 23 and 24 are irregularly shaped plates which are pivotally mounted on respective pivot shafts 25 and 26, the axes of which project in a direction normal to the support plate 15. Each pivot shaft 25 and 26 is riveted at one of its ends to the plate 15 and in final assembly at its other end to the plate 18 thereby functioning to hold the support plates in assembled relationship as well as providing for pivotal support of the latch elements.
The latch elements are swingable in counterswinging directions and are vertically displaced relative to one another with overlapping portions.
Each latch element 23-24 has a semi-circular pin receiving notch 27 adapted in door latched condition to encompass the striker pin 12 carried in the body pillar jamb face 13. Each latch element has an extension or finger 28 at one side of the notch 27 which, as will be explained with reference to FIG. 6 and 7, are adapted to overlie each other to provide a barrier against relative unlatching movement between the latch elements and the striker pin in door latched condition. Rearwardly of the extension or finger 28, each latch element has a straight peripheral surface 29 extending tangentially from a curved surface 31 which is interrupted by an abutment 32. The abutment 32 is a step to a further curved surface 33 of greater radius than the curved surface 31. The curved surface 33 is interrupted by a pair of spaced steps or abutments 34 and 35. From the abutments 34 and 35 back to the notch 27, each latch element has a substantially outwardly radially extending apex portion 36.
The side flange 21 of the primary support plate 15 is provided with an enlarged opening bounded by inwardly turned flanges 37 and 38. These flanges lead into a substantially V-shaped notch 39 in the primary support plate having flanged guide edges 41 and 42 for guiding the striker pin 12 into proper alignment between the latch element notches 25. The V-shaped notch 39 terminates in a rounded bight 43.
The latch elements are spring-urged in counter or opposite directions toward unlatched position by a compound spring 44 having counterwound coiled end portions 45 and 46 encompassing the respective pivot shafts 25 and 26. The coiled portions 45 and 46 have free end portions 47 and 48 hooked over the edge of the latch elements in engagement with the respective abutments 32. The spring coiled end portions bias the latch elements toward unlatched position to the extent permitted by stops 49 and 51 in the side flange 21.
Cooperable with the abutments 34-35 on the latch elements 23-24 is a swinging detent means 52 pivotally mounted on a shoulder rivet 53 secured to the primary support plate 15.
The detent means 52 is a plural armed lever member. A first one of the lever arms, the arm 54, extends from the pivot 53 generally longitudinally of the primary support plate so as to lie to one side of the latch elements 23-24. The lever arm 54 has spaced abutments 55-56 on its latch element contiguous side which are adapted to coact with the abutments 34-35 on the latch elements, as will be further explained.
The second arm 57 of the detent means 52 extends generally transversely of the primary support plate and lies in contiguous relationship to the latch element 23. Intermediate its ends the arm 57 has a cam surface or abutment 58 which under certain conditions abuts the latch element 23 peripheral surface 31, see FIG. 7.
The detent means 52 is spring-loaded in latch element engaging direction by a compression spring 59 which extends between a downwardly projecting arm 61 on the detent means and a tab 62 formed on the lower portion of the primary support plate 15.
The present latch mechanism is preferably operated from the inside of the vehicle door through the medium of a remote control mechanism (not shown) connected to a longitudinally shiftable draft link or rod 63 which is pivotally connected to the lower end of a vertically depending arm 64 of a bell crank 65. The bell crank 65 is pivoted on the shank of a shoulder rivet 66 (See FIG. 2) secured to the primary support plate 15. The bell crank 65 has a substantially horizontally extending arm 67 adapted to underlie an extension 68 on the end of the detent means arm 57. The shoulder rivet 66 on which the bell crank 65 is mounted is secured to a flange 69 which extends in a direction normal to the surface of the primary support plate 15. Movement of the draft link 63 in a direction toward the latch mechanism, i.e., in the direction of the arrow 71 in FIG. 1, causes the bell crank 65 to be swung to raise its arm 67. This causes a lifting movement to be applied to the arm 57 of the detent means 52 causing the arm 54 of the latter to be swung away from the latch elements.
Release of the detent means 52 from the latch elements 23-24 through the remote control mechanism on the inside of the vehicle door is independent of the actuation of the detent means from the outside of the vehicle door.
The latch mechanism components for releasing the detent means from the latch elements from the outside of the vehicle door are supported on the secondary support or cover plate 18 and reference is now made to FIG. 4 for the orientation of these components. As was noted above, disengagement of the detent means 52 from the latch elements 23-24 is accomplished by swinging the detent means in a direction to cause the arm 54 to move away from the latch elements. This is accomplished from the outside of the vehicle door by a system of levers and links which comprise a bell crank lever 72 pivotally mounted on a shoulder rivet 73 fastened to the secondary support plate 18. The bell crank lever 72 has a generally horizontally extending arm 74 adapted to be connected by a link 75 to an outside operator (not shown). The bell crank lever 72 also has a generally vertically extending arm 76 which at its upper end has a tab portion 77 which fits through a slot 78 in an elongated link 79.
The link 79 is pivotally supported at its upper end on a pivot stud 81 carried on a generally horizontally extending member 82 which is pivoted intermediate its ends by a pivot stud 83 secured to the secondary support plate 18.
At its end opposite the pivoted end, the link 79 has a tab 84 which in unlocked condition of the latch mechanism 10 lies in abutting relationship to a flange 85 on the edge of the detent lever arm 54. Thus, when the bell crank lever 72 is swung in a counterclockwise direction, as viewed in FIG. 2, the interconnection between the bell crank lever 72 and the link 79 results in the latter also being swung in a counterclockwise direction. The tab 84 will then abut the flange 85 and cause the detent means 52 also to be swung in a counterclockwise direction away from and out of engagement with the latch elements 23-24. This permits the latch elements, if in a latched condition, to move to an unlatched condition so that the vehicle door may be opened relative to the body panel.
If the member 82 is shifted about its pivot axis 83 in a clockwise direction, the tab 84 on the end of the link 79 will bypass the flange 85 on the detent means arm 54. This effectively renders the outside operator ineffective to disengage the detent means 52 from the latch elements 23-24. The latch mechanism then is considered in a "locked" condition. The member 82 thus may be considered a locking control member.
The locking control member is shiftable about the pivot axis 83 from a latch mechanism locking position to a latch mechanism unlocking position from either the inside or the outside of the vehicle door. As best seen in FIG. 1, the vehicle door is provided with a push button 86. Such a button conventionally is accessible at the upper edge of the door inside of the window glass. The push button 86 is connected by a link 87 to an apertured appendage 88 on the locking control member 82. With the push button 86 in a raised position as shown in FIG. 1, the locking control member 82 is in the normal latch mechanism operative position shown in FIGS. 2 and 4. In this position, as has been explained, the link 79 is swingable to cause the detent means to be disengaged from the latch elements.
The second locking link 89 is connected to the apertured end 91 of the locking control member. The link 89 at its upper end is coupled to a conventional key cylinder mechanism through which the link may be shifted up and down to swing the locking control member about its pivot axis 83.
The locking control member 82 is held in either latch mechanism locked or latch mechanism unlocked position by a toggle spring 92 extending between the control member 82 and the secondary support plate 18. One other spring of importance is a spring 93 which is mounted on the secondary support plate 18 and urges the link 79 in a counterclockwise direction as viewed in FIG. 4 out of abutting relation with the flange 85 on the detent means arm 54. Every time the link 79 is actuated by actuation of the bell crank 72 it is restored to its inoperative position by the spring 93.
Referring now to FIGS. 4, 6 and 7, several different operative relationships of the detent means to the latch elements are shown. In FIG. 5, for example, detent abutments 55 and 56 on the detent means arm 54 are shown interposed between the abutments 34 on the latch elements 23 and 24. In this condition the latch elements 23 and 24 are not in their fully latched position. This occurs when insufficient force is exerted on the door during closing movement to cause the striker pin, as it enters between the fingers 28 into abutting relation with the apex portions 36, to drive the latch elements toward a fully latched condition. In the FIG. 5 condition, the door is latched but is not held fully against rattling or vibratory motion.
FIG. 6 illustrates the normal fully latched condition of the latch elements in which the abutments 55 and 56 on the detent means arm 54 are interposed between the abutment surfaces 35 on the latch elements 23 and 24. In this condition the striker pin 12 is tightly gripped by the latch elements so as to hold the door against movement in any direction.
In FIG. 7, the relationship of the detent means to the latch elements may be considered as that which occurs after the detent means 52 is moved to a fully disengaged position relative to the latch elements by either the inside or outside operator. The latch elements 23 and 24 are held in their fully unlatched position by the compound spring 44. The detent means under the influence of spring 59 now should be restored to an abutting relationship to the latch elements, such as shown in FIG. 3. It will be noted in FIG. 3 that the corner edge of the abutment 55 on the detent means arm 54 is in abutting relation to the curved edge 33 of the latch element 23. Under the influence of the spring 59, upon the latch elements being moved toward latched condition the detent abutments 55 and 56 should first move into the FIG. 5 relationship, and then, if sufficient force is exerted on the door, into the final latched position shown in FIG. 6.
For any of a number of reasons, such as the failure of spring 59 or the accumulation of road dust, dirty grease or even an ice coating between the detent means and the primary support latch plate 15, conditions could arise in which the spring 59 is unable to urge the detent means 52 in a clockwise direction as viewed in FIG. 7. With the detent means inhibited from movement from this position the door would rebound to an open position since the detent means abutments 55 and 56 would not achieve either the FIG. 5 or the FIG. 6 relationship to the abutments on the latch elements.
According to the present invention, the detent means arm 57 with its cam surface 58 lies in abutting relation to the peripheral surface 31 on the latch element 23 so that as the latch element is swung in a counterclockwise direction upon engagement with the striker pin 12, the abutment 32 will engage and kick the cam surface 58 downwardly thus driving the detent means 52 in a clockwise direction. The relationship of the latch element abutment 32 to the cam surface 58 on the detent means arm 57 is such that this action occurs just as the latch element abutments 35 are in a position of slight overtravel relative to one another so that the abutments 55 and 56 on the detent means arm 54 are able to position themselves between the latch element abutments 35. Thus, even if for any reason spring 59 is ineffective to accomplish its function of restoring the detent means to normal latch element holding position, the interaction between the latch element 23, abutment 32 and the cam surface means on the detent means arm 57 insures that the latching relationship will be achieved.
It will be understood that the invention is not to be limited to the exact construction shown and described, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.