SHUTTER MECHANISM FOR A LATCH

Abstract: A latch (10) has a housing (12) defining a mouth (14), a ratchet (18) pivotally mounted to cooperate with the mouth to move between a latched condition and an unlatched condition, a pivotally mounted pawl (30) engaging the ratchet (18) and rotatable to selectively engage the ratchet (18) to retain the ratchet (18) in the latched condition, and a release lever (40) pivotally mounted and pivotally connected to the pawl (30) for effecting movement of the pawl to disengage the ratchet. A shutter (50) is slidably mounted to move between a cover condition positioned to cover the ratchet (18) and an open condition allowing relative movement of a striker to latch and unlatch with the ratchet (18). The shutter (50) is biased to the cover condition.

Description: SHUTTER MECHANISM FOR A LATCH Field of the Invention This invention relates to a latch for a motor vehicle. More particularly, this invention relates to a shutter mechanism for keeping foreign material out of the latch when the latch is exposed. Background of the Invention A latch typically has a housing with a mouth which receives a striker and a ratchet and pawl mechanism that cooperates with the mouth to selectively retain the striker. The pawl is manipulated to release the ratchet and unlatch the striker. When the closure panel, such as a tail gate, liftgate, sliding door, and the like, is open, the latch is exposed allowing debris to enter the housing, which debris can cause the ratchet to malfunction. Additionally, as the ratchet is lubricated, a person accessing the vehicle could contact the latch and the lubricant, which is undesirable as the lubricant is difficult to remove from clothing. Summary of the Invention The disadvantages of the prior art may be overcome by providing a latch assembly in which the mouth is selectively coverable in order to reduce the ingress of debris into the housing, and to shield an operator from contact with the inner mechanisms of the latch. According to one aspect of the invention, there is provided a latch assembly having a housing with a mouth for receiving a striker. The latch assembly has a shutter mounted to the housing which is movable between a cover configuration for covering the mouth and an open configuration allowing the striker to enter the mouth. The shutter may have a shutter biasing mechanism operably connected to the shutter and the housing for urging the shutter toward the closed configuration. The shutter may have first and second shutter elements moveable away from each other in moving from the cover to the open configuration. The first and second shutter elements may include cam surfaces which are acted upon by the striker to move the shutter toward the open configuration as the striker enters the mouth. The shutter biasing mechanism may have at least one shutter spring connected to the first and second shutter elements for urging the first and second shutter elements toward each other. The shutter biasing mechanism may include a shutter guide acting between the housing and the first and second shutter elements for guiding movement of the first and second shutter elements relative to the housing. The shutter biasing mechanism may further include a shutter spring connected to the first and second shutter elements. The shutter guide may include cooperating slots and pins in the first and second shutter elements and housing for guiding the first and second shutter elements for sliding movement relative to the housing. The latch assembly may include a ratchet mounted to the housing for movement between a latched position and an unlatched position. The latch assembly may further include a pawl mounted to the housing for movement between an engaged position holding the ratchet in the latched position to prevent withdrawal of the striker, and a disengaged position allowing movement of the ratchet toward the disengaged position to allow withdrawal of the striker from the mouth. A release lever may also be connected to the pawl for moving the pawl toward the disengaged position. A ratchet spring may be mounted between the ratchet and the housing to bias the ratchet toward the disengaged position. A pawl spring may further be mounted between the pawl and the housing for urging the pawl toward its engaged configuration. Description of the Drawings Preferred embodiments of the present invention are described below with reference to the accompanying drawings in which: Figure 1 is a perspective view illustrating a latch assembly according to the present invention from its outboard side; Figure 2 is a perspective view from the inboard side of the latch assembly of Figure 1; Figure 3 is a front elevation of a latch assembly of Figure 1; Figure 4 is an end elevation of the front of the latch assembly of Figure 1; Figure 5 is an end elevation of the rear of the latch assembly of Figure 1; Figure 6a is a front elevation corresponding to Figure 3, but illustrating a striker adjacent a mouth of the latch assembly; Figure 6b is a view corresponding to Figure 6a, but showing the striker entering the mouth; Figure 6c is a view corresponding to Figures 6a and 6b, but sowing the striker in the mouth; Figure 7 is a top plan view of the latch assembly of Figure 1 ; and, Figure 8 is a bottom plan view of the latch assembly of Figure 1. Description of Preferred Embodiments A latch assembly illustrative of the present invention is generally indicated by reference 10 in the accompanying drawings. The latch assembly 10 has a housing 12 with a mouth 14 for receiving a striker 16 which is illustrated in Figures 6a through 6c. A ratchet 18 is mounted to the housing 12 for movement between a latched position showing in Figure 6c and an unlatched position shown in the remaining Figures. In the latched position, the ratchet 18 cooperates with the housing 12 to trap the striker 16 in the mouth 14. In the unlatched position, the striker is removable from the mouth 14. A ratchet spring 20 in Figure 8 may be provided to act between the ratchet 18 and housing 12 to bias the ratchet toward its unlatched position. A pawl 30 is mounted to the housing 12 for movement between an engaged position and a disengaged position. In the engaged position, the pawl 30 engages the ratchet 18 to hold it in its latched position to prevent withdrawal of the striker 16 from the mouth 14. In the disengaged position, the pawl allows movement of the ratchet 18 toward its unlatched position to allow withdrawal of the striker 16 from the mouth 14. A pawl spring 32 in Figure 7 may be provided to act between the pawl 30 and the housing 12 to urge the pawl 30 toward its engaged position. A release lever 40 is operably connected to the pawl 30 for moving the pawl 30 toward its disengaged position. It will be appreciated by those skilled in vehicle latching assemblies that the above description describes typical latching assemblies for vehicle doors, decks, hoods, liftgates or tailgates. The present invention relates to apparatus associated with such latch assemblies for shielding the mouth of the latch assemblies from debris. Accordingly, it will therefore further be appreciated that such apparatus, described in detail below and referred to as a "shutter" may be adapted to a variety of typical latch assemblies. A shutter according to the present invention is generally indicated by reference 50. The shutter 50 may include a first shutter element 52 and a second shutter element 54 movable between a cover configuration covering the mouth 14 as illustrated in Figures 1, 2, 3, 4, 5, 6a and 6b and an open configuration illustrated in Figure 6c. In the open configuration, the shutter 50 allows entry of the striker 16 into the mouth 14. The shutter 50 is mounted to the housing 12 in a manner which allows the first and second shutter elements, 52 and 54 respectively to move in opposite relative directions. A representative mounting arrangement is illustrated which includes slots 60 in the housing 12 which slidably receive pins 62 extending from the first and second shutter elements, 52 and 54 respectively. Other arrangements may also work such as providing slots in the first and second shutter elements, 52 and 54 respectively, and corresponding pins on the housing 12. Possibly, the first and second shutter elements, 52 and 54 respectively, may be pivotably mounted to the housing 12 for a clamshell type of movement. The first and second shutter elements, 52 and 54 respectively, may be provided with respective cam surfaces 56 and 58. The cam surfaces 56 and 58 cause opposite relative movement of the first and second shutter elements, 52 and 54 respectively, in response to the striker 16 being urged into the mouth 14 as shown sequentially in Figures 6a through 6c. Suitable biasing means such as a shutter spring 70 may be provided to urge the shutter 50 toward its cover configuration. The shutter spring 70 acts between the first and second shutter elements, 52 and 54, respectively. The shutter spring 70 also acts between the shutter 50 and the housing 12 by virtue of the constraint placed on the movement of the pins 60 in the slots 62. Other biasing means may be apparent to those skilled in such devices, such as having a separate spring for each shutter element mounted directly between the respective shutter element and the housing 12. In use, as the striker 16 is withdrawn from the mouth 14, the shutter 50 moves into its cover configuration to at least partially close the mouth and shield the latch assembly 10 from the entry of debris into the mouth 14. The above description is intended in an illustrative rather than a restrictive sense. Variations to the exact embodiments described may be apparent to those skilled in such structures without departing from the spirit and scope of the present invention as defined by the claims set out below.

Claims: WHAT IS CLAIMED IS: 1. A latch assembly comprising: a housing having a mouth for receiving a striker; and, a shutter mounted to said housing and movable between a cover configuration for covering said mouth and an open configuration allowing such striker to enter said mouth. 2. A latch assembly as claimed in claim 1 wherein: said shutter includes a shutter biasing mechanism operably connected to said shutter and said housing for urging said shutter toward said closed configuration. 3. A latch assembly as claimed in claim 2 wherein: said shutter includes first and second shutter elements movable away from each other in moving from said cover to said open configuration; said first and second shutter elements include cam surfaces which are acted upon by said striker to move said shutter toward said opening configuration; and, said shutter biasing mechanism includes at least one shutter spring connected to said first and second shutter elements for urging said first and second shutter elements toward each other. 4. A latch assembly as claimed in claim 3 wherein: said shutter biasing mechanism includes a shutter guide acting between said housing and said first and second shutter elements for guiding movement of said first and second shutter elements relative to said housing; and, said shutter biasing mechanism further includes a shutter spring connected to said first and second shutter elements. 5. A latch assembly as claimed in claim 4 wherein said shutter guide includes cooperating slots and pins in said first and second shutter elements and said housing for guiding said first and second shutter elements for sliding movement relative to said housing. 6. A latch assembly comprising: a housing having a mouth for receiving a striker; a ratchet pivotally mounted to said housing to cooperate with the mouth for movement between a latched position and an unlatched position; a ratchet spring is mounted between said ratchet and said housing to bias said ratchet toward said unlatched position; a pawl mounted to said housing for movement between an engaged position holding said ratchet in said latched position to prevent withdrawal of said striker and a disengaged position allowing movement of said ratchet toward said unlatched position to allow withdrawal of said striker from said mouth; a pawl spring is mounted between said pawl and said housing for urging said pawl towards said engaged configuration; a release lever connected to said pawl for moving said pawl toward said disengaged position; and, a shutter mounted to said housing and movable between a cover configuration for covering said mouth and an open configuration allowing said striker to enter said mouth. 7. A latch assembly as claimed in claim 6 wherein: a shutter biasing mechanism is operably connected to said shutter and said housing for urging said shutter toward said closed configuration. 8. A latch assembly as claimed in claim 7 wherein: said shutter includes first and second shutter elements movable away from each other in moving from said cover to said open configuration; said first and second shutter elements include cam surfaces which are acted upon by said striker to move said shutter toward said open configuration as said striker is urged toward said mouth; and, said shutter biasing mechanism includes at least one shutter spring connected to said first and second shutter elements for urging said first and second shutter elements toward each other. 9. A latch assembly as claimed in claim 8 wherein said shutter biasing mechanism includes a shutter guide acting between said housing and said first and second shutter elements for guiding movement of said first and second shutter elements relative to said housing; and, said shutter biasing mechanism further includes a shutter spring connected to said first and second shutter elements. 10. A latch assembly as claimed in claim 9 wherein said shutter guide includes cooperating slots and pins in said first and second shutter elements and said housing for guiding said first and second shutter elements for sliding movement relative to said housing.

Inventors: HRNJAK ALEKSANDAR, LAI EUGENE, HRNJAK, ALEKSANDAR, LAI, EUGENE
Applicants: ATOMA INT CORP, HRNJAK ALEKSANDAR, LAI EUGENE, ATOMA INTERNATIONAL CORP., HRNJAK, ALEKSANDAR, LAI, EUGENE
Application year: 2000
Main classification: E05B15
IPC codes: E05B15, E05B17