Abstract:
A mechanical latch for securing a moveable structure to a fixed is provided. The mechanical latch includes a movable catch pin and a proximity pin disposed within a housing cavity. Both pins are spring loaded to urge the pins towards the moveable structure, and both pins also include stops projecting therefrom to limit this movement. An insert member is attached to the housing between the pins and has an end which is engaged by the stops. In an engaged position, the catch pin interacts with a slot in the moveable structure. In the engaged position, the proximity pin and the moveable structure generate a gap between its stop and the insert which allows the other catch pin to be selectively drawn rearward from its latched condition. A peg carried by the catch pin is urged into the gap and against the insert which secures the catch pin in a latched condition. As the proximity pin and the moveable structure move progressively apart, the stop contacts the peg and forces it out of the gap, thereby allowing the catch pin to be moved into its static position ready for a subsequent operation to stow the moveable structure. The latched position of the catch pin being substantially identical to the static position of latch pin.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention generally relates to latches. More particularly, the present invention relates to a mechanical latch that can be reset in response to certain activities. More specifically, but without restriction to the particular embodiment and/or use which is shown and described for purposes of illustration, the present invention relates a mechanical hold down latch that is used to secure a vehicle top in a stowed position. 
     2. Discussion 
     Motor vehicles used for personal transportation are produced in many different types and styles in order to meet the needs of a wide variety of customers. Because of the various needs of different customers, automotive manufacturers produce large cars, small cars, minivans, trucks, sport utility vehicles, and convertibles. Convertibles are designed for a specific segment of customers that prefer or desire these types of vehicles. Convertibles have a vehicle top that can be placed in the up position where the top acts as a conventional vehicle roof. Convertibles also allow a vehicle top to be placed in a down or stowed position whereby the top is positioned such that the vehicle operators are exposed to the open air. It is this feel of open-air motoring that has made convertibles popular with consumers over the years. 
     When convertible tops are placed in the stowed position, there is a tendency for the top to vibrate and rattle while the vehicle is in motion. There is, obviously, a need to provide means to reduce the vibration that can cause noise and excessive wear and tear on the vehicle top. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a principal objective of the present invention to provide a truly versatile and unique latching system for securing a moveable structure to a structure that is stationary relative thereto. 
     It is also an objective of the present invention to provide a latch system for a convertible vehicle top. 
     It is another objective of the present invention to provide a latch mechanism for use to secure a vehicle top while the top is in the stowed position. 
     It is still another objective of the present invention to provide a latch system that can be cycled from unengaged to engaged and back. 
     It is a further objective of the present invention to provide a latch system that can be used to compensate for build variations in the motor vehicle. 
     It is yet a further objective of the present invention to provide a latch system that will reset to its static position after any contact therewith. 
     In one form, the present invention provides a mechanical latch for securing a moveable structure to a stationary structure, the moveable structure being the header structure of a vehicle top in the preferred embodiment. The mechanical latch includes a catch pin that is adapted to be received by a slot in the moveable structure. The latch is carried by housing having a cavity for reception of the catch pin and a proximity pin. Both the catch and proximity pins include a spring that urges the pins to move in a longitudinal direction towards the moveable structure. The catch pin and the proximity pin both include a stop projecting therefrom. An insert is provided that attaches to the housing and cooperates with the stops of the catch pin and proximity pin to limit longitudinal movement of the pins. The catch pin also includes a slanted peg that is urged towards the proximity pin by a spring attached thereto. When the proximity pin contacts the moveable structure, it is forced rearward thereby creating a gap between the stop thereof and the insert. When the releasing of the moveable structure is desired, the catch pin is translated rearward by the aid of a pin lever having a bracket and a cantilevered activation arm. As the catch pin is translated rearward, slanted peg is urged into the gap formed between the stop of the proximity pin and the insert. The contact between the peg and the insert locks the catch pin is a position longitudinally rearward of its static position called the latched position. If contact between the proximity pin and the moveable structure is reduced, then the stop thereof can contact the slanted peg and force it upward, thereby eliminating the gap. At this point, the catch pin is free to translate in a longitudinal manner until the stop of the catch pin contacts the insert to a static position. 
     Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from a reading of the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a vehicle having a convertible top with the top in the up position; 
     FIG. 2 is a perspective view of a vehicle having a convertible top with the top in the stowed position; 
     FIGS. 3A and 3B are exploded views of the latch assembly of the present invention; 
     FIG. 4 is cross sectional view through the latch assembly of the present invention in the static position as the vehicle top is moving from the up position to the stowed; 
     FIG. 5 is a cross sectional view through the latch assembly of the present invention as the vehicle top is moved downward from the position shown in FIG. 4; 
     FIG. 6 is a cross sectional view through the latch assembly of the present invention with the catch pin engaged and the vehicle top in the stowed position; 
     FIG. 7 is a cross sectional view through the latch assembly of the present invention with the vehicle top in the stowed position and the catch pin retracted in a latched condition; 
     FIG. 8 is a cross sectional view through the latch assembly of the present invention with the vehicle top raised slightly from the stowed position with the catch pin still retracted in a latched condition; and 
     FIG. 9 is a cross sectional view through the latch assembly of the present invention with the vehicle top raised such that the lower proximity pin is fully extended. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, FIG. 1 illustrates a motor vehicle  10  of the convertible type illustrating the present invention. Motor vehicle  10  has a body referred to generally by numeral  12  that surrounds a passenger compartment  14 . Body  12  includes a pair of doors  16  that are adapted for access to passenger compartment  14 . Doors  16  are disposed on opposing sides of passenger compartment  14  and rearward of the vehicle windshield  18  that projects upward from body  12 . Motor vehicle  10  includes a convertible vehicle top  20  that can be translated from a closed position where it provides shelter to passenger to compartment  14  to a stowed position. FIG. 1 illustrates vehicle top  20  in a position between the closed position and the stowed position and FIG. 2 illustrates vehicle top  20  in the stowed position. In the stowed position, vehicle top  20  is disposed behind passenger compartment  14  in a recess  21  designed to receive top  20 . During the translation of vehicle top  20 , a cover bezel  22  is pivoted to open and allow greater access to recess  21 . Vehicle top  20  typically pivots in two places  17  and  19  to provide for proper storage such that the forward most portion  24  of vehicle top  20  is disposed in recess  21  adjacent to passenger compartment  14  while in the stowed position. While in the stowed position it is desirable to reduce movement of vehicle top  20  to reduce noise and wear. A mechanical latch (not shown in FIGS. 1 and 2 but whose location is indicated generally by numeral  25 ) is provided to reduce movement of top  20  and is disposed in recess  21  adjacent to said passenger compartment  14  to contact the forward most portion  24  of vehicle top  20 . 
     FIGS. 3A and 3B illustrate different views of the mechanical latch  26  of the present invention in an exploded arrangement. With reference to both views, mechanical latch  26  includes a housing  28  having a generally rectangular cavity  30  formed by back wall  32  and two opposing walls  34  and  36 , a bottom wall  38 , and a top wall  40  extending therefrom. Cavity  30  includes an opening  42  on the end opposite of back wall  32 . Opening  42  is circumscribed by a bezel  44  that is connected to and projects outwards from two opposing walls  34  and  36 , bottom wall  38 , and top wall  40 . Back wall  32  includes two preferably circular openings  46  and  48 . A top opening  46  is disposed vertically above bottom opening  48 . Side walls  34  and  36  each includes a slot  50  formed substantially parallel to the top wall  40  and the bottom wall  38 . Each slot  50  includes a hole  52  formed therein a specified distance from bezel  44 . 
     Cavity  30  is adapted to receive a top catch pin  60  and a bottom proximity pin  62  through opening  42 . Top catch pin  60  includes a main rectangular body  64  that includes a slanted front surface  66 . Extending from the back surface  68  of the body  64  is a control rod  70  that is adapted to be received by the top circular opening  46  in the back wall  32  of housing  28 . Control rod  70  is disposed through the center of a circularly wound spring  72 . Spring  72  contacts the back wall  30  of housing  28  on one end and contacts back surface  68  of body  64  on the opposing end, more specifically a circular counterbore  67  formed on back surface  68  on the opposing end. Spring  72  acts to force the body  64  of the top catch pin  60  away from the back wall  32  and towards the vehicle top  20  in a longitudinal direction indicated generally by arrow  33  (see FIGS.  3 A and  4 ). Body  64  also includes a bottom surface  74  that includes a recess  75  formed therein to receive a spring  76  and a slanted peg  78 . Slanted peg  78  is hollow forming a counterbore to receive one end of spring  76  therein. Spring  76  urges the slanted peg  78  downward. Slanted peg  78  includes an angled end surface  82  that faces the back wall  32  of housing  28 . Bottom surface  74  of body  64  also includes a pair of stops  84  that project downward therefrom. Stops  84  are substantially identical and spaced a distance  86  apart. 
     It should be appreciated that the elements described as springs in the present invention could be any type of resilient element that can provide a spring force to the desired component. Metal circularly wound springs are used in the preferred embodiment of the present invention but the invention is not limited to this type of spring, any resilient element that provides a spring force would be within the scope and fair meaning of the present invention. 
     Bottom proximity pin  62  includes a body  90 , control rod  92 , spring  94 , slanted front surface  96 , and a back surface  98 . The control rod  92  is adapted to be received by the bottom circular opening  48  disposed in the back wall  32  of housing  28 . The bottom proximity pin  62  includes a top surface  100  that includes a stop  102  that is centrally located on the width of the body  90 . Stop  102  is adapted is slide between the distance  86  between the pair of stops  84  projecting from the bottom surface  74  of the top catch pin  60 , therefore, the width of stop  102  is less than the distance  86 . 
     Also included in the mechanical latch  26  is insert  106 . Insert  106  is generally flat and plate like in construction and includes a rear face  108 , two opposing side faces  110  and  112 , a top face  114 , a bottom face  116 , and a forward face  118 . Opposing side faces  110  and  112  each include an outwardly projecting clip formation  120  adapted to be secured within holes  52  in the opposing walls  34  and  36  of the housing  28 . Clip formations  120  include a rearward facing angled surface  122 . Insert  106  also includes two oval shaped voids  124  and  126  that extend through the insert from the top face  114  to the bottom face  116 . Voids  124  and  126  are adapted to provide flexibility and allow inward movement or retraction of clip formations  120  when the insert  106  is inserted into slots  50  of the opposing side walls  34  and  36  of the housing  28 . Angled surface formation  122  is adapted to facilitate this inward movement. When the clip formations  120  reach the holes  54 , the clip formations  120  project into holes  52  to secure insert  106  in housing  28 . 
     The mechanical latch  26  also includes a pin lever  130  that is pivotally attached near the back wall  32  of the housing  28  via pivot flange  135 . Pin lever  130  includes two upward extending posts  131  and  132  that define a U-shaped bracket  134 . The U-shaped bracket  134  is adapted to receive the free end of control rod  70  that extends through the top opening  46  and the free end of control rod  92  that extends through the bottom opening  48 . It should be appreciated that the distance  136  between the upward extending posts  131  and  132  is greater than the diameter of each rod  70  and  92 , thereby allowing longitudinal movement of the control rods  70  and  92  therein. Post  131  includes an attachment finger  138  that is adapted for securing a spring  140  thereto. Spring  140  is preferably attached to a spring attachment tab  202  of a bracket base  200 . Bracket base  200  is preferably coupled to a structural part of the vehicle, such as a vehicle cross member (not shown). Pin lever  130  also includes an activating arm  142  cantilevered from the pivot flange  135 . The activating arm  142  is connected to a cable  144  to provide remote mechanical pivoting activation thereof. The cable  144  is extends through a bore formed in bracket base  200  and is connected to a switch or lever in the passenger compartment  14  of the vehicle  10 . When the switch or lever is activated, a tension force is introduced to cable  144 , which imposes a force on activating arm  142  of the pin lever  130 . The bracket base provides positioning and strength to cable  144  in a localized area. This tension force causes pin lever  130  to pivot about pivot point  146  in a direction indicated by arrow  148 . Pivot pin  146  is preferably attached to pivot pin tab  204  projecting from bracket base  200 . The pivoting motion causes spring  140  to extend. When the tension of cable  144  is removed, spring  140  retracts and returns pin lever  130  to its stationary position whereby U-shaped bracket  134  is in contact with the back wall  32  of housing  28 . 
     Assembly of latch mechanism  26  begins by placing the bottom surface  74  of the top catch pin  60  adjacent to the top surface  114  of insert  106  thereby forces slanted peg  78  into recess  75  formed in bottom surface  74 . Rear wall  108  of insert  106  is positioned against the forward edge of stops  84 . Then top surface  100  of proximity pin  62  is brought into contact against bottom surface  116  of insert  106 . Stop  102  should then be disposed in the space  86  created between the pair of stops  84  with the forward edge of the stops  84  in contact with rear edge  108 . This arrangement is then slid into housing  28  until clip formations  120  are locked in holes  52  as described earlier in the description of the preferred embodiment. Once insert  106  is in place, the longitudinal motion of catch pin  60  and proximity pin  62  is limited by the contact of stops  84  and  102  with the rear face  108  of insert  106 . 
     With reference to FIG. 4, once the mechanical latch  26  is assembled a C-shaped clip  162  is placed in a groove  164  formed in the control rod  70  of the top catch pin  60 . C-shaped clip  162  bends outward slightly during installation and then resiles when in place to form a snug fit within groove  164 . C-shaped clip  162  provides a larger radius to control rod  70  such that upward extending posts  131  and  132  of the U-shaped bracket  134  can contact clip  162 . Control rod  70  includes a second groove  166  formed closer to the free end of the control rod  70  than is groove  164 . The function of the second groove  166  will be described in detail subsequently. 
     FIG. 4 provides an assembled mechanical latch  26  illustrated in a cross sectional view of its static position. Mechanical latch  26  is disposed in a stationary or fixed body  150  at the forward edge of recess  21  as shown in FIG.  1 . Fixed body  150  is stationary relative to the vehicle top  20 . The vehicle top  20  folds in such a way that the forward most portion  24  thereof is stowed adjacent to the forward edge of recess  21 . Forward most portion  24  of vehicle top  20  includes a header structure  152  comprised of steel, aluminum, rigid plastic, or another structural material that extends laterally across top  20 . A fabric  154  is preferably attached to header structure  152  that substantially covers the entire vehicle top  20 . Header structure includes a slot  156  formed therein to cooperate with the catch pin  60  of mechanical latch  26  to secure the vehicle top  20  in the stowed position as shown in FIG.  2 . The height  155  of slot  156  is slightly larger than the height  160  of the top catch pin  60  to facilitate ready reception of the catch pin  60  therein. 
     It should be appreciated that the bottom proximity pin  62  is retained in the rest position shown in FIG. 4 by contact between its stop  102  and end surface  108  of insert  106 . In the same manner, catch pin  60  is retained in the rest position shown in FIG. 4 by contact between stops  84  and end surface  108  of insert  106 . Stops  84  are not visible in FIG. 4 because stops  84  are not disposed along the centerline of the mechanical latch  26  and pin  60  in the cross sectional view in FIG.  4 . 
     Slanted front end  66  of top catch pin  60  is adapted to contact the header structure  152  of the vehicle top  20  as the forward edge  24  of top  20  is moved downward into recess  21 . Header structure  152  has a curved lower edge  168  to progressively contact the slanted front end  66  of catch pin  60 . As top  20  is moved downward, the body  64  of top catch pin  60  is moved rearward into cavity  30  against the urging of spring  72 . FIG. 5 illustrates this inward movement of the top catch pin  60  as the top  20  is moved into a stowed position. As top  20  is moved further downward, curved lower edge  168  of header structure  152  next contacts the slanted front face  96  of the proximity pin  62 , as shown in detail in FIG.  5 . As top  20  is moved even further downward, proximity pin  62  is progressively translated further rearward. This continues until the front edge  170  of the slanted front end  66  reaches slot  156  in the header structure  152 . As front edge  170  of the slanted front end  66  reaches slot  156 , spring  72  forces body  64  of top catch pin  60  forward until stops  84  contact rear surface  108  of insert  86  (not shown in the cross sectional view). In this position, the top catch pin  60  extends into slot  156  such that a portion  172  thereof blocks vertical movement of the header structure  152  of the vehicle top  20 . This position is defined by an engaged catch pin  60  and top  20  in the stowed position as is illustrated in FIG.  6 . It should be appreciated that the engaged position of the catch pin  60  is substantially identical to its static position as shown in FIG.  4 . Catch pin  60  limits vibration and movement of vehicle top  20  while in the stowed position. It should be appreciated that while top  20  in the stowed position, the bottom proximity pin  62  is still maintained by structure  152  such that a gap  180  is formed rearward of insert  106  along the centerline of the proximity pin  62 . 
     To remove vehicle top  20  from the stowed position, an operator of the vehicle activates a lever or the like that applies tension to cable  144  and applies a force on activating arm  142  to cause pivoting  148  of pin lever  130  about pivot point  146  against the force of spring  140  (Not shown in FIG. 7 due to cross-sectional view). Pin lever  130  is pivoted as illustrated in FIG. 7 such that U-shaped bracket  134  contacts clip  162  attached to control rod  70  of top catch pin  60  which moves the top catch pin  60  rearward to the left. Pin lever  130  forces top catch pin  60  rearward until the forward edge  182  of slanted peg  78  passes the rear face  108  of insert  106 . As forward edge  182  reaches gap  180  between face  108  and stop  102 , spring  76  forces slanted peg  78  downward into gap  180  such that after the tension in cable  144  is removed, top catch pin is locked into a position rearwardly of its static and engaged position. This position is called the latched position and is illustrated in FIG.  7 . 
     With top catch pin  60  removed out from slot  156 , vehicle top can be raised from its stowed position. As top  20  is raised as shown in FIG. 8, the edge  168  of header  152  allows the proximity pin  62  to move forward under the influence of spring  94 . As proximity pin  62  is forced forward, gap  180  diminishes in size due to stop  102  moving forward therewith. As stop  102  of proximity pin  62  moves forward, it contacts angled surface  82  of the slanted peg  78  and moves peg  78  upward against the spring  76  as shown in FIG.  8 . 
     As top  20  is raised further as shown in FIG. 9, stop  102  moves to the right to completely close gap  180  and move peg  78  upwards sufficiently to eliminate horizontal contact between peg  78  and rear face  108  of insert  106 . This frees the top catch pin  60  to translate forward to the right with the assistance of spring  72  as shown in FIG.  9 . At this point, the top  20  can be raised to reduce contact with mechanical latch  16  and the two pins  60 ,  62  are reset to their static positions as shown in FIG.  4 . It should be appreciated that when the proximity pin  62  closes gap  180 , slot  156  of header structure  152  has been moved sufficiently above the top catch pin  60 . Therefore, longitudinal movement of the top catch pin  60  towards the vehicle top will not result in insertion of catch pin  60  into slot  156  thereby allowing top  20  to be freely moved upwards. 
     The present invention provides many advantages other than those specifically described above, for example, the present invention is versatile and adaptable to a vehicle build process. Often acceptable tolerances of one part can be magnified when parts of a conglomerate are assembled. This type of build-up tolerances can affect the position of vehicle top  20  in the stowed position. If every part in the assembly is built with little or no deviation from design, then the situation shown in FIG. 4 will occur. On the other hand, it may occur where the assembly of the top  20  deviates slightly from design and it is impractical to disassemble the top  20  for slight deviations. These variance can cause the header structure  152  of the top  20  to be disposed further away from fixed body  150  than desired. If this occurs, the present invention can be modified to adapt to the situation. A modified insert  106  can be used to allow the catch pin  60  and the proximity pin  62  to extend further into recess  21 . This is accomplished by simply having an insert  106  with less structure behind the clip formations  120 , thereby allowing catch pin  60  and proximity pin  62  to translate farther away from the back wall  32  of the housing  28  before stops  84  and  102  contact insert  106 . The modified insert  106  is essentially identical but includes a rear surface that is moved away from rear wall  32 , as shown in dotted lines in FIGS. 3A &amp; 3B. If such an insert is used the c-shaped clip  162  is placed on the groove  166  closest to the distal end of control rod  70  to compensate for the shifted position of the catch pin  60 . Another advantage of this design is the fact that the latch  26  will always return to the static position when not in contact with any other object. Therefore, if for some reason contact with the latch is initiated by a person or object other than the vehicle top, the latch will reset to the static position as soon as such contact is removed, this prevents the possibility of the latch getting stuck in an improper position by various contact therewith. 
     While the above description constitutes the preferred embodiment of the invention, it will be appreciated that the invention is susceptible to modification, variation, and change without departing from the proper scope or fair meaning of the accompanying claims. Modifications would include providing electronic controls or actuation of portions or the apparatus.