Abstract:
The present invention provides a buckle and frame for a restraint system resisting to a harsh environment. The buckle comprising a frame having a base wall, the base wall includes a debris exit opening; and a cover which encloses the frame and forms at least one vent opening and at least one passage which couples the debris exit opening to the vent opening. Debris, dust and other foreign objects which find there way into the buckle are not necessarily trapped but rather are presented with a means of exiting the buckle via the vent opening.

Description:
FIELD OF THE INVENTION 
     The invention relates, generally, to a safety restraint system having a buckle and tongue and, more particularly, a belt restraint system for restraining an individual in a seat having a buckle and tongue adapted for use in a harsh environment. 
     BACKGROUND OF THE INVENTION 
     Commercially viable applications of the invention include, for example, off-road applications such as recreational equipment (go-karts, dune buggies, all terrain racing, etc.), cargo tie-down industry, heavy equipment applications, forklift or material handling equipment, and agricultural equipment. 
     The prior art safety restraint systems includes combination buckle and tongue devices incorporated in a belt or webbing system to safely secure an individual or occupant in a seat. Many of the prior art systems include a locking mechanism having a frame and a pawl for locking the tongue to the frame. 
     U.S. Pat. No. 3,921,262 discloses a load bearing safety belt buckle construction. The buckle includes a housing having a latch plate with a cam surface. A tongue plate having an abutment surface is inserted into the housing whereupon a spring urges the cam surface to engage with the abutment surface. U.S. Pat. No. 5,267,377 discloses a multi point buckle assembly. The buckle assembly includes a metal base. A latch member includes a latch lug biased by a latch spring for engaging an opening of a tongue. 
     Safety restraint systems for use in a harsh environment, such as off-road or earth moving equipment, are subject to particular problems. For example, the prior art buckle assembly frame acts in an enclosing manner that houses the sliding button and traps dust and debris between the button surfaces and the frame surfaces. 
     The ejection slide provides a plastic-on-plastic arrangement. Such an arrangement may suffer from galling due to the harsh dusty environment. The cover of certain prior art systems include features which introduce horizontal ledges which allow dust and debris to settle and accumulate thereupon and which eventually may gall internal components of the system. The size of the button face area is relatively small and obstructed too easily to activate, particularly by someone wearing heavy working gloves. 
     The prior art systems suffer other disadvantages. For example, the portion of the sliding button which acts upon the locking pawl engaging device is not sufficient. In addition, the button portion does not provide a backup in the event the primary device fails. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a buckle for a safety restraint system adapted for harsh environments, such as abusive handling, moisture, corrosion, dust and debris. 
     It is a further object of the present invention to provide a buckle for a safety restraint system especially adapted to be used in off-road or earth moving equipment. 
     It is a further object of the present invention to reduce the number of components required. 
     It is a further object of the present invention to provide a buckle for a restraint system designed to allow dirt and debris which has gotten into the buckle, the ability to easily pass through and exit the buckle. 
     The present invention therefore provides a buckle for a restraint system resistant to a harsh environment. The buckle comprising a frame having a base wall, the base wall includes a debris exit opening; and a cover which encloses the frame and forms at least one vent opening and at least one passage which couples the debris exit opening to the vent opening. Debris, dust and other foreign objects which find there way into the buckle are not necessarily trapped but rather are presented with a means of exiting the buckle via the vent opening. 
     The present invention also provides a one piece frame used in a buckle for a restraint system resistant to a harsh environment. The frame having a base wall, a pair of opposed facing side walls, and a pair of flanges. The base wall having a debris exit opening. The pair of opposed facing side walls extending up from the base wall, each side wall having a tab deformed inward and in opposed facing relation with the tab on the other side wall, each of the tabs has a lower edge which forms an upper limit of a guide for the tongue when it is inserted into the frame, and when the tongue is not inserted the lower edge forms an upper limit for a latch plate. The pair of flanges extending toward one another from the side walls in a common plane, the flanges adapted for receiving a button release slide adapted to release a tongue from the frame, each flange having a notch, whereby sliding action of button release slide causes dirt and other debris to fall through the notch and avoid being lodged between the flange and the button release slide. 
     The present invention further provides a buckle for a restraint system resistant to a harsh environment. The buckle having a frame, tongue, latch plate and a leaf spring. The frame having a base wall, the base wall including a front edge at a mouth of the buckle. The tongue having one end for insertion into the frame, the one end having an opening and forming a pawl engaging inner face. The latch plate having a front edge which is pivotally coupled at the front edge of the frame, and a pawl located on a side opposite from the front edge for engagement with the pawl engaging inner face. The leaf spring having a first end which is secured to the buckle at the mouth, and a mid portion located under the latch plate and which urges the latch plate upward and away from the base wall into a locked position, and another end having an elbow which rests upon the base wall and extends upward from the base wall to form a tongue engaging end, whereby when the tongue is inserted into the frame, the latch plate is urged downward against the base wall and against the force of the leaf spring, further insertion of the tongue causes the one end of the tongue to come in contact with the tongue engaging end, and wherein further insertion of the tongue causes the tongue engaging end to deflect and load the tongue under spring force, and wherein further insertion of the tongue causes the pawl engaging inner face to slide over the pawl at which time the pawl is urged upward by the leaf spring and engages with the pawl engaging inner face, thus whereupon subsequent downward movement of the latch plate causes the spring loaded tongue engaging end of the leaf spring to urge the tongue out of the buckle. 
     The present invention also provides a buckle for a restraint system resistant to a harsh environment. The buckle having a frame, tongue, button release slide, latch plate and a leaf spring. The frame having a base wall, the base wall including a front edge at a mouth of the buckle The tongue having one end for insertion into the frame, the one end having a pawl engaging inner face. The button release slide slideably secured to the frame and adapted to release the tongue from the frame, the button release slide having a pair of depending inner legs at one end, the depending legs each presenting an inclined surface. The latch plate having a front edge which is pivotally coupled at the front edge of the mouth, and a pawl located distal from the front edge for engagement with the pawl engaging inner face, and an upwardly inclined surface located distal from the front edge of the latch plate. The leaf spring having a mid portion located under the latch plate and which urges the latch plate upward and away from the base wall into a locked position, whereby when the tongue is inserted into the frame, the latch plate is urged downward toward the base wall and against the force of the leaf spring, and wherein further insertion of the tongue causes the pawl engaging inner face to slide over the pawl at which time the pawl is urged upward by the leaf spring and engages with the pawl engaging inner face, and whereupon subsequent actuation of the button release slide causes the pair of depending inner legs to urge the upwardly inclined surface of the latch plate downward against the spring force of the leaf spring so as to disengage the pawl from the tongue. 
     The present invention further provides a buckle for a restraint system resistant to a harsh environment. The buckle having a housing, a tongue and a compressive spring mechanism. The buckle housing having a mouth opening and a latching mechanism. The tongue having one end for insertion into the mouth opening for engagement and latching with the latch mechanism. The compressive spring mechanism secured to the tongue and arranged to be compressed as the tongue is inserted into the mouth opening, whereby upon release of the tongue from the latching mechanism, the tongue is urged out of the mouth opening under the compressed spring force of the latch mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the buckle of a first preferred embodiment of the present invention. 
         FIG. 2  is a perspective view of a connector which is used with the buckle of  FIG. 1 . 
         FIG. 3  is a perspective view of a frame incorporated in the buckle of  FIG. 1 . 
         FIG. 4  is a perspective view of a frame incorporated in the buckle of  FIG. 1 , shown together with a latching plate. 
         FIG. 5  is a perspective view of a leaf spring incorporated in a second preferred embodiment of the present invention. 
         FIG. 6  is a perspective view of a button release slide of the buckle of  FIG. 1 . 
         FIG. 7  is a perspective view of the buckle of  FIG. 1 , with the upper portion of the cover removed. 
         FIG. 8  is a partial cross section and cutaway side view of  FIG. 7 , with the latch plate in the locked position. 
         FIG. 9  is a close-up of  FIG. 8 , but with the latch plate in the unlocked position. 
         FIG. 10  is a perspective view of a connector of  FIG. 2  but shown without the bellow. 
         FIG. 11  is a partial cutaway and cross sections side view of the frame, a latch plate and tongue of the second preferred embodiment of the present invention. 
         FIG. 12  is a perspective view of the lower portion of the cover of  FIG. 1 . 
         FIG. 13  is a perspective view of a upper portion of the cover of  FIG. 1 . 
         FIG. 14  is a perspective view of a buckle and connector assembly of a preferred alternative embodiment of the present invention. 
         FIG. 15  is an exploded view of the buckle assembly of  FIG. 14 . 
         FIG. 16  is a perspective view of the frame of the buckle of  FIG. 14 . 
         FIG. 17  is a perspective view of the button release slide of  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a perspective view of a buckle  10  in accordance with a first preferred embodiment of the present invention. The buckle  10  includes a cover  12  having an upper portion  14  and a lower portion  16 . The upper portion includes a first top surface  18  which is raised with respect to a second top surface  20 . The first top surface of the cover includes a cutout  22  to accommodate a button face  24 . The button face includes a top surface  26  and a front surface  28  which is essentially at a right angle to the top surface of the button face. The upper portion of the cover also includes a front surface  30 . The cover when assembled forms a mouth or vent opening  32  at a front end and a vent opening  34  at a rear end. A cable  36  can be seen to extend from the rear end of the cover. 
       FIG. 2  shows a perspective view of a connector  38  for use with the buckle of  FIG. 1 . At one end of the connector, a tongue  40  is provided having an opening  42  which forms a pawl engaging inner face  44 . The tongue also includes a first and second angled surface  46 . The other end of the connector includes a belt slot  48  for receiving a belt or other securing material (not shown). The angled symmetric surfaces  46  help guide the connector plate more easily into the buckle. The symmetry of the connector allows the connector to be attached to the buckle irrespective of the orientation. A bellow  50  includes a first end  52  having an opening  54  and a second end  56  having a rectangular sleeve portion  58  with an open end  60 . The bellow surrounds a substantial portion of the connector and the sleeve portion includes two openings  62  which are aligned with the belt slots. The connector is coupled with the buckle by means of the tongue being inserted into the mouth. When the connector is inserted into the buckle, the bellow is compressed by the front surface of the cover and develops a spring force urging the locked connector in a direction out of the buckle. 
       FIG. 3  shows a frame  70  which is used in the buckle of  FIG. 1 . The frame includes a base wall  72  and two side walls  74  which extend up from the base wall. A pair of inclined flanges  76  are provided at the top of the side walls and extend towards one another in a common plane. The inclined flanges each include a notch  78 . The flanges each include an edge  80  facing the rear of the frame. The flanges also include a leading edge at the front of the frame. A large radius on the leading edge  82  of the topward surface of buckle frame is included to assist in smooth interaction. The base wall includes a hole  84  for connecting the cable to the buckle. The side walls further include a pair of opposed facing slots  86  which assist in the connection of the cable to the buckle. The base wall includes a front edge  88  which is bent and curled so as to be redirected towards the rear of the frame and form a recess  90 . A tab  92  is bent up from the base wall and extends upwardly terminating at an end  94 . The base wall further includes a debris exit opening  96 . The side walls each include a tab  98  deformed inwardly. The side wall tabs each include an upper edge  100  and a lower edge  102  ( FIG. 4 ). 
       FIG. 4  shows the frame of  FIG. 3  but further with a latch plate  104 . The latch plate includes a front edge  106  which is received by the recess of the frame. The latch plate further includes a raised pawl  108  and a pair of upwardly inclined surfaces  110 . The partial side view of  FIG. 4  better demonstrates that the inclined flanges are oriented to slope down toward the back of the buckle or frame. The latch plate of  FIG. 4  is shown to be pivoted at the recess so that the upwardly inclined surfaces are in a raised or locked position and in contact with the lower edge of the deformed tabs. However, when the latch plate is lowered, the lower edges of the deformed tabs together with the curved front edge of the frame and the side walls define a guide or channel for receiving the tongue. 
       FIG. 5  discloses a leaf spring  120  for use in an alternative preferred embodiment of the present invention. However, the leaf spring of  FIG. 5  is actually a modified version of the leaf spring used in the first preferred embodiment of the present invention. The leaf spring of  FIG. 5  will now be described in connection with its use in the first preferred embodiment of the present invention. The leaf spring includes a first end  122  having a curved end or hook portion  124  which is used to receive the front edge of the latch plate. A second end  126  includes an elbow  128  having a hole  130 . The hole receives the tab which extends up from the base wall of the frame. Thus the curved end and hole of the leaf spring restrain the leaf spring within the frame. An arched mid portion  132  of the leaf spring extends under the latch plate and urges the latch plate in an upward and locked direction. In the embodiment of  FIG. 1 , an optional tongue engaging end  134  is not used and therefore the second end is shortened and does not extend as high as shown in  FIG. 5 . A required height of the second end for each embodiment will be understood from the description which follows. 
       FIG. 6  discloses the button release slide  140  which includes the button face, a pair of wing style tabs  142  extending from the sides and a spring boss  144  which extends from the back of the button release slide. A pair of depending inner legs  146  are shown, as well as a pair of outer legs  148  which each include a stop  150 . 
       FIG. 7  shows the frame and other components received by the lower portion of the cover. It can be seen that the button release slide includes grooves  152  on either side which receive the inclined flanges. The button release slide is able to slide back and forth with respect to the frame along the flanges. The cable is shown to include a cable end fitting  154  which includes a hole  156  which is aligned with the hole of the frame. A bracket  160  is shown having ends  162  which extend through the slots of the frame. The bracket further includes a hole  164  in a mid portion  166  which is aligned with the hole of the cable end fitting and the hole of the frame. A fastener  168  is used to secure the cable end fitting between the frame and bracket. A button spring retainer or end  170  extends up from the mid portion of the bracket and is aligned with the spring boss of the button release slide. A spring  172  ( FIG. 8 ) extends between and is captured by the button spring retainer and spring boss. The spring urges the button release slide outwardly from the mouth of the buckle towards a locked position. The bracket further includes downwardly bent tabs  174  ( FIG. 8 ) on either side of the cable end fitting so as to further secure the cable end fitting in position. A switch  176  is also shown in the lower portion of the cover and includes a pivotal switch arm  178 . 
       FIG. 8  shows a partial cutaway cross section side view of the frame and button release slide as well as other components. The button release slide is shown biased by the spring in the outwardly extending position. The outer legs are shown to include a depending inclined surface  184  which is in engagement with the upwardly inclined surface of the latch plate. The position of the button release slide shown in  FIG. 8  allows the latch plate to be urged by the leaf spring (not shown in  FIG. 8 ) in an upward locked position. It will be noted that in the locked position the pawl extends above the end of the tab bent upwardly from the base wall. 
     The following describes the tongue being inserted into the buckle with the button release slide in the extended locked position. It will be appreciated that if the tongue is inserted into the mouth of the buckle, the tongue will extend over the front edge of the frame and below the lower edge of the deformed tabs. As the tongue is further inserted, the end of the tongue will come into engagement with the latch plate and urge the latch plate to pivot downward against the force of the leaf spring. Eventually the tongue will come into contact with the end of the upturned tab. Further insertion of the tongue will cause the inner face of the tongue to pass the pawl at which time the latch plate will be urged upward by the leaf spring and the pawl will come into contact with the inner face of the tongue and latch the tongue with the buckle. 
       FIG. 9  shows the button release slide having been depressed, such as by the user, and moved in a direction to the left as viewed in  FIG. 9 . The inclined surface of the outer legs slides against the upwardly inclined surface of the latch plate, urging the latch plate to pivot or rotate in a downward direction together with the pawl against the force of the leaf spring (not shown in  FIG. 9 ). The release slide will continue to travel on this path until the upper frame edge runs into the end of the groove in the side of the button. This groove has a maximum amount of travel built in to keep the operator from over traveling the locking pawl, as well as to constrain or hold the release slide component in a particular orientation. When the release slide reaches the maximum amount of travel, the locking pawl will be rotated to the unlatched position, which is slightly beyond the position actually required for the connector to be released. As the tongue is prevented from moving downward with the pawl as a result of engagement with the end of the upward bent tab, eventually the pawl will be removed from engagement with the inner face of the tongue. At this point, the latch plate is in the unlocked position and the compression force of the bellow will assist in urging the tongue out of the buckle. 
     There is an added feature to the function of the button release slide, and the actuation of releasing the buckle assembly. The wing style tabs on each side of the button slide forward and backward as the button face is depressed and released. As the component moves in this fashion the wing style tabs act in a sweeping fashion. It is intended that this function sweep and clear any dust and debris out of the channel located in the side of the button. The wing style tabs work together with the two notches purposely cut into the top surface of the buckle frame. As the wings sweep back and forth they carry or push any dust and debris past said notches or vented openings to clear the sliding path of the button release component. This sweeping action occurs every time the release button is depressed or released. This function takes place independent of the locking mechanism. Grooves in the slide of button are designed to have large amounts of clearance to allow for ease of dirt and debris to be swept past and eject through notches in the frame; in essence slots are much larger than thickness of frame. 
     The inclined flanges minimize size and material, improves on industry standard devices orientation for ergonomic release by operators, and minimize the release stroke and overall travel of the button release slide. 
       FIG. 10  shows the connector as used in both the embodiment shown in  FIG. 2  as well as the embodiment which does not include the bellow but rather includes the leaf spring as shown in  FIG. 5  together with the optional tongue engaging end. The connector is shown to include shoulders  190  on either side. It will be appreciated that regardless of which embodiment of the connector is used, with the connector inserted in the buckle, and regardless of the orientation of the connector with respect to the buckle, one of the shoulders will come into engagement with the pivotal switch arm of the switch, thus activating the switch and developing a signal to indicate that the connector is fully inserted in the buckle. 
       FIG. 11  shows a partial cutaway cross section side view of the frame and other components of the second preferred embodiment of the present invention. The frame is shown with the tongue inserted with the inner face in locking engagement with the raised pawl. The latch plate has been urged downwardly by the insertion of the tongue. The leaf spring is shown to be in position with the tongue engaging end in engagement with the tongue. It will be appreciated that for the second preferred embodiment, the tongue engaging end must extend above the end of the tab. When the tongue is initially inserted, it comes into engagement with the tongue engaging end, and is further inserted into the buckle so as to depress the tongue engaging end away from the mouth of the buckle and thereby loading a spring tension force against the tongue. However, the engagement of the tongue with the pawl prevents the tongue from being urged out of the buckle by means of the tongue engaging end of the leaf spring.  FIG. 11  shows that the tongue is guided by means of the lower edge of the inwardly deformed tab and the front edge of the frame. 
       FIG. 12  shows the lower portion of the cover. The lower portion includes an inner face  200  upon which support ribs  202  extend along a length thereof. Channels or passageways  204  are formed between the adjacent support ribs. A cutout  206  of the lower portion defines a portion of the vent opening perimeter. A first raised area  208  and a second raised area  210  of the ribs form a recess  212  which receives the frame. Support walls  214  further define the recess and maintain the position of the frame. The second raised area of ribs will be in general alignment with the front edge of the frame and thus assist together with the button release slide in providing a guide or channel for the entrance of the tongue. A switch support rib  216  is further shown to secure the switch to the cover. A cutout  218  forms part of the perimeter for the mouth  32 .  FIG. 13  shows the upper portion of the cover having an inner face  220  and similarly providing support ribs  222  and support walls  224 . A cutout  226  defines a portion of the vent opening perimeter. Another cutout  228  defines a portion of the perimeter of the mouth  32  The cover design intentionally bias dust and debris to the center of buckle and urge it to exit opening in back. 
       FIGS. 14–17  disclose a preferred alternate multi-point embodiment. The operation of the multi-point embodiment is much like the operation of the preferred embodiment. The major difference is that multiple pawls are used, one pawl for each connector. In the case of  FIGS. 14–17 , two connectors are used, thus two pawls are used. A button release slide is still used to push the pawls into the unlatched position against the pawl leaf springs that urge the pawls toward the latched position. For the purpose of explaining the nuances and differences of the operation of the multi-point embodiment as compared to the preferred embodiment, no description of the covers is included because the same features are used as described earlier. 
       FIGS. 14–17  show that the overall design of the multi-point embodiment is similar in that the button release slide rides on inclined flanges that are bent inward from the sidewalls. The ramps provided on the button release slide are used to depress the pawls to the unlatched position as the user pushes the button in the rearward direction against the urging of the leaf spring. 
     In use, webbing is placed through web slots so that the buckle can be used in three-point or five-point restraint applications. The terms “three-point” and “five-point” refer to the number of anchorage points built into the restraint system. For example, in a five-point restraint, anchorage points are located as follows: one for each shoulder, one in front of the crotch, and one on each side of the hips. Webbing is placed through eyelet holes at each seat anchorage point and through the three web slots on the buckle device. 
     To lock the multi-point buckle, either the connectors can be latched simultaneously or separately. The leaf spring urges the pawls to the latched position. When the user pushes the connector through the connector entry slot  242  and in between the guidance flanges  244 , the connector acts as a wedge which forces the pawl downward to the unlatched position against the pawl spring until the leaf engaging slot passes over the pawl tang and until the pawl engaging inner face goes far enough until the leaf spring can force the pawl upward so that the pawl engagement face protrudes into the pawl engaging slot and blocks the connector from backing out of the mechanism. Since each pawl works independently, each connector can be pushed in the same manner. 
     Another feature of the pawl is that it includes upward bent walls to create a guide way  246  for the connector. The preferred embodiment guides the connectors by use of the frame sidewalls. Since multiple pawls may be in this system, multiple walls are needed for connector guidance, therefore the guidance is built-in to each pawl. The pawls rotate about an imaginary axis through the hinge boss  248  and hinge hole  250 . 
     To prevent sideways movement of the pawls, a separator  252  is included on the button release slide. When the mechanism is assembled, this feature is located between the pawls and provides the lateral support need so that if sideways loads are placed on the connectors, the separator  252  will prevent the connectors and pawls from moving and possible disconnecting prematurely. 
     This embodiment also has the dust sweeping features built into the frame and the button release slide. The notches allow the release of dust and debris as the wing style tabs move over the inclined flanges when the user pushes the button release slide. 
     Since this embodiment would not be attached to a cable, the button spring retainer is included as a part of the frame. Also, the pawls springs are held in the mechanism by the pawl spring retainer. 
     There are many features within the internal design of the cover that are associated with the funneling and biasing of dust and debris through and out of the system. The features include the two protruding sets of support walls to brace the sides of the buckle frame, and at the same time not introduce a ledge for dust and other foreign objects to settle onto. This is accomplished by introducing a ramp on all support walls that protrude in a direction normal to the sidewalls of the buckle frame. Note that when the front and back covers are assembled the inner cavities of these support walls will be sealed. Support ribs are included to the inside base of the cover to add strength, as well as raise said buckle frame above the bottom of the cover and allow dust and debris to easily flow under the frame and exit the buckle system. The support ribs mentioned above run to the back of the cover essentially creating slots in the back of the buckle that allow dust and debris that gets channeled through the ribs to run directly to the back of the cover and out through the vents. They also support the back end of the buckle frame. In the top portion of the cover there are support ribs that protrude out from the inside surface. These are intended to support the cover by acting against the top portion of the buckle frame. The overall design intent is to surround the buckle frame with support from all directions to improve durability against impact and shock. Also, the intent is to protectively enclose all of the buckle components and continue to have open space to allow for good ventilation. The design intent is to let all dirt and debris that is able to get into the system, the ability to easily pass through and exit the system.