Abstract:
Vehicle body restraint systems including buckles for latching and retaining latch plates associated with safety belts wherein the buckles includes latching mechanisms having oppositely oriented release mechanisms which are operative in such a manner that any force applied to one release mechanism which would act to release a latch plate creates an increased force on the opposing release mechanism to retain the latch plate in a locked position. Release of the latch plates can only occur upon the simultaneous activation of the opposing release mechanisms by manual force applied in opposite directions.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a Divisional of application Ser. No. 10/769,870, filed Feb. 3, 2004, entitled NON-INERTIAL SAFETY RESTRAINT BELT BUCKLE SYSTEMS, in the name of the same inventor, which is a Continuation-In-Part of application Ser. No. 10/462,738, filed Jun. 17, 2003, entitled, NON-INERTIAL SAFETY RESTRAINT BELT BUCKLE SYSTEMS, in the name of the same inventor, now abandoned. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention is generally directed to vehicle safety restraint systems including shoulder and lap-type seat belts and more particularly to such restraint systems which incorporate locking mechanisms for preventing release of latch plates from buckles of the restraint systems due to inertial forces created during vehicle accidents, such as in vehicle rollovers. The restraint systems can only be released by simultaneously manually maneuvering opposing release mechanisms in opposite directions.  
       BACKGROUND  
       [0003]     Body restraint systems including seat belts, lap belts, shoulder harnesses and the like have been credited with saving numerous lives which otherwise would have been lost in vehicular accidents. The positive benefits obtained due to body restraints systems has been so recognized that, in the United States, the use of seat belts is mandated in all states.  
         [0004]     Since their inception, there have been numerous innovative advances made to improve upon the safety and reliability of vehicle body restraint systems. Improvements have been made to the belt and belt materials, the manner in which the belt restraint systems are mounted within vehicles, the manner in which such restraint systems may be automatically adjusted to provide proper tension to suit not only safety standards but to also provide for a measure of passenger comfort and, further, to improve upon the security of the locking devices and belt buckles associated with such systems.  
         [0005]     Most conventional vehicle body restraint systems incorporate a belt which either crosses in front of the lap or diagonally across the body of the vehicle operator or passenger in such a manner as to not adversely interfere with a region of an individual&#39;s neck. Belts are retained by latching assemblies including belt buckles into which latch plates carried by the belts can be inserted so as to automatically become locked to the buckles which are normally anchored relative to vehicle frames.  
         [0006]     Conventional systems generally utilize two types of release mechanisms for allowing latch plates to be removed from buckle housings such that drivers and passengers can disembark vehicles. A first or side release system includes an operating release button which is generally resiliently urged outwardly at an angle which is perpendicular to an axis or line of insertion of the latch plate into a buckle housing. A second type of conventional release system is known as an end release system and includes an operating lever or button for releasing the latch plate from the buckle housing and which lever is mounted at an end of the buckle housing.  
         [0007]     Currently, virtually all types of latching mechanisms for body restraint systems in automotive vehicles are subject to premature release when subjected to at least one mode of inertial force which is created under various conditions resulting from collisions, rollovers and other types of loss of vehicle control. Side release latching assemblies or mechanisms, referred to as Type  1  and Type  6  in the industry, will inertially release when subjected to lateral forces which are applied to a backside of a buckle during a vehicle collision or rollover. Such latching assemblies will also release by the release buttons being forceably engaged by an object in a vehicle accidently depressing the buttons during an accident, collision or rollover, thereby prematurely destroying the effectiveness of the restraint systems which can cause severe or deadly injury to persons using the systems.  
         [0008]     By way of example, if a person&#39;s hip strikes the backside of a buckle frame, the interior latch will engage a latch plate of a seat belt and will release when the striking force level is sufficient to cause the inertia of the latch mass, relative to the acceleration and displacement of the buckle frame, to compress a leaf spring and unlatch the buckle.  
         [0009]     End type release latching systems will inertially release due to the mass of the release buttons associated therewith when taken into consideration the mass of movement of latch plates and the direction of rotational release of the latch plates when subjected to an upward or upward and lateral force opposite a locking direction of latch dogs associated with such mechanisms, especially during vehicle rollovers. This lateral mode of failure occurs when an occupant is more apt to be ejected from a vehicle and thus can result in severe bodily injury or death.  
         [0010]     An example of end release latching system for seat belts is disclosed in U.S. Pat. No. 4,358,879 to Magyar. The system uses a release button which is pushed down to release the latch plate as opposed to being pushed laterally as in the side release systems.  
         [0011]     Virtually all end release buckles, generally referred to as Type II buckles, operate using an over-the-center mechanism so the actual latch uses either a fairly weak compression spring or a leaf spring for a latching force. A so called “lock for the latch” is a rod or bar that follows an “L” shaped track where the lock bar moves laterally across the buckle frame in a direction of latch movement and then moves vertically along a leg of the “L” and behind the latch after the latch goes over-the-center to its latched position; thus supposedly locking the latch from moving laterally due to lateral forces acting on the buckle frame that would inertially move the latch laterally relative to the buckle frame.  
         [0012]     However, the end release buckles have a release button, release slider, lock bar (pin) latch and two compression springs, all of which have mass. One spring actuates the latch laterally and the other spring acts against the latch plate to keep a locking edge in contact with a latch surface or “dog” and applies an upward force against the release button. This spring also acts to eject the latch plate from the buckle when the latch button is depressed and the latch is disengage.  
         [0013]     When vertical forces, or forces with enough vertical component on a buckle, such as forces created by impacts to a bottom of a vehicle in a rollover, are sufficiently high enough, the buckle latch will release. The design of these buckles is such that release requires both a vertical (longitudinal) and horizontal (lateral) component in many cases because any vertically upward forces cause equally vertical downward inertial forces to the release button and related components, which causes them to move in a downward (release) direction due to their mass and acceleration relative to the buckle frame. When the components of the release mechanism approach an elbow of the locking “L” slot, the locking pin or bar follows the path of the slot and releases the latch and the compression spring against which these inertia forces are acting, and ejects the latch plate.  
         [0014]     The forces acting on a latch plate/buckle assembly that create inertia forces in a release direction come from various and foreseeable sources and directions and always follow Newton&#39;s Law. Some of these are:  
         [0015]     a) vertical to horizontal forces acting on a vehicle and thus a buckle assembly from impact to the ground during vehicle rollovers;  
         [0016]     b) vertical to horizontal forces acting on a vehicle and thus on a buckle assembly from impact to the vehicle from another vehicle, fixed object or other movable object within a path of the vehicle;  
         [0017]     c) vertical to horizontal forces acting on a buckle assembly by objects within a vehicle, such as occupants or loose objects;  
         [0018]     d) vertical to horizontal forces acting on a buckle assembly from it being driven into objects within a vehicle, such as a center console between a driver and a passenger or between vehicle occupants; and  
         [0019]     e) vertical to horizontal forces acting on a latch plate and release mechanism mass from impulses resulting from emergency management loop release as well as harness mounted air bags and the like where tension or a harness/lap belt webbing is suddenly tightened or released causing a large, near longitudinal impulse force into the buckle, latch plate and release mechanism mass sufficient to cause an acceleration of the mass of the release mechanism parts to develop an inertia force exceeding a release mechanism spring force acting against a release mechanism mass.  
         [0020]     A latch plate weighs anywhere from approximately two (2) to five (5) ounces, depending on whether it is a slip, partial slip or slip lock latch plate. A weight (mass) of the release components of the buckle (button, slider, locking pin, etc.) is a fraction of the latch plate weight.  
         [0021]     The dynamic problem with the end release buckles is that when there is an upward force or upward component of force acting on the buckle or a downward impulse from sudden tensile loading/unloading of seat belt webbing through the latch plate, the latch plate mass applies a downward inertia force or impulse that drives an unlatch mechanism downward toward an unlatch position, accelerating the unlatch mechanism masses downward and thus causing the latch to release. Any horizontal or lateral force acting on the buckle frame in an opposite direction of the unlatch direction compounds the unlatching due to acceleration forces acting on the buckle frame.  
         [0022]     The above modes of failure are inherent in virtually all conventional side and end release latching mechanisms of conventional vehicle restraint systems. The side release buckle systems are generally simpler and have fewer moving parts and thus are more economical to construct and to install, whereas the end release systems are more complex having multiple moving parts and are thus more expensive to manufacture.  
         [0023]     In view of the foregoing, there remains a need to further improve upon the reliability and effectiveness of vehicle body restraint safety belt systems to ensure that the latching mechanisms associated therewith cannot be accidently released during substantially any type of vehicular movement including vehicle rollovers caused during accidents, collisions or resulting from loss of control of a vehicle, such as by operator error or vehicle equipment failure. There is a further need to provide for improvements in vehicle body restraint systems which permit the latching assemblies to be more reliable and more economic to construct.  
       SUMMARY OF THE INVENTION  
       [0024]     The present invention is directed to vehicle body restraint systems which include buckles for latching and restraining latch plates carried by seat or lap belts and safety harnesses. Preferred embodiments of the invention are disclosed. The embodiments are designed to prevent inertial release of safety restraint buckle or latching assemblies associated with vehicles by requiring intentional manual release of two equally resisted and oppositely oriented push button release mechanisms associated with the buckles such that release of latch plates from the buckles is only possible by the simultaneous manual movement of the oppositely oriented release mechanisms or buttons.  
         [0025]     Each locking mechanism utilizes equal and opposite locking forces against opposing lock release buttons such that if a force, or component of force, acts on a body of a buckle which is inline with an actuation direction of one of the release buttons, an equal and opposite force acts against the opposing release button thereby locking it into tighter engagement with the latch of the buckle assembly. Thus, the locking mechanism can not release by the application inertial forces to the buckle assembly. The release of the latch plate can only occur upon the deliberate and simultaneous manual application of force to the two opposing release buttons in opposite directions.  
         [0026]     The safety belt assembly of each of the restraint systems of the invention is provided with a latch plate which is insertable so as to be locked and retained within a buckle housing having internal latching components for engaging and preventing the removal of the latch plate until manually released. The buckle housings including an opening in which a latch plate is slidably received. Mounted interiorly of each buckle housing is at least one movable latch which is operable in a first position to engage within an opening in the latch plate to thereby prevent withdrawal of the latch plate until the at least one latch is moved from the opening in the latch plate.  
         [0027]     In a first embodiment of the invention, a single latch is movably mounted within the buckle housing against a resilient element or spring which normally urges the latch to its first or “locking” position. The latch includes a latch dog which is engageable with an edge defining the opening in the latch plate to thereby prevent withdrawal of the latch plate once it has been inserted within the buckle housing. The latch is operably connected to a pair of oppositely oriented release buttons which are mounted through opposite sides of the buckle housing. Each of the push or release buttons is engaged with a separate arm of the latch such that both arms of the latch must be engaged simultaneously by the oppositely oriented release buttons to urge the latch to a second or “release” position wherein the latch dog is free of the opening in the latch plate thus permitting the release of the latch plate from the buckle housing.  
         [0028]     As noted, a spring is mounted within the buckle housing so as to apply a constant force to the latch in the first locking direction such that, upon insertion of the latch plate within the buckle housing, the latch locking dog is urged into engagement with the latch plate as soon as the opening of the latch plate passes the latch dog of the latch.  
         [0029]     The buckle housing includes an internal frame component on which the opposing push buttons are guidingly engaged. The housing is also configured such that the push buttons are recessed relative thereto to thereby prevent accidental engagement with, and inadvertent actuation of, the buttons. A resilient element, such as a spring, is mounted between each of the push buttons so as to apply an equal and opposite force urging each of the buttons to a first and outer locking position. With this arrangement, when a force is applied to move one of the push buttons to a second release position wherein the push button is pushed inwardly of the housing, an opposite force is directed to the opposing push button thereby providing additional force to maintain the opposite push button in its first or locking position. Therefore, unless both push buttons are moved to their inner release positions simultaneously, the latch can not be moved to its second release position as one of the push buttons will be engaging an arm of the latch to prevent its movement from its first locked position. Further, the greater the force applied to one push button to move it to its release position, the greater the force applied to the opposite release button to retain it in its locked position.  
         [0030]     In the first embodiment, the latch plate is specially constructed so as to simultaneously urge each of the push buttons to their second release positions upon the insertion of the latch plate into the buckle housing. In this respect, the latch plate includes a pair of forwardly spaced tangs having beveled edges which are engageable in slots in each of the push buttons so as to cam each push button to its second release position upon the insertion of the tangs until the opening in the latch plate is aligned to allow the latch dog of the latch to be resiliently urged within the opening to thereby lock the latch plate within the buckle housing.  
         [0031]     In a second embodiment of the invention, a pair of latches are mounted within the buckle housing on opposite sides of a channel in which the latch plate is slidingly received when inserted through the opening in one end of the buckle housing. Each of the latches is resiliently urged to a first locking position in which lock dogs associated with each latch are engageable within the opening in the latch plate with the oppositely oriented latch dogs being positioned generally side-by-side when the latches are in the first locked position. Further, two push buttons are mounted through opposite sidewalls of the housing as with the first embodiment. Each push or release button includes an extended catch member which is generally unshaped and designed to engage a separate one of the latch plates so as to prevent movement of the latch plate from the first locking position to a second release position wherein the latch dogs associated with the latches are moved from the opening in the latch plate to thereby permit the withdrawal of the latch plate.  
         [0032]     Each push button further includes a beveled surface for engaging an opposing side of the latch associated therewith which side is also beveled, such that, upon movement of the push buttons from their first outer locking position inwardly to their second release position, the beveled surfaces will urge the adjacent latch to be moved to its second release position.  
         [0033]     In order to ensure that both push buttons must be moved to their second release positions simultaneously to release the latch plate from the buckle housing, a pair of springs are provided between each of the catch portions of the push buttons and the opposing push button. If force is applied to move either push button to its second release position, an opposite force is directed by the interconnecting spring or resilient element to urge the opposing push button outwardly with increased force so as to maintain the opposite push button in its first locked position. Therefore, only by the simultaneous application of force to each of the opposing push buttons to move them inwardly relative to the buckle housing can both latches be moved to their second release positions to permit the latch plate to be withdrawn from the buckle housing.  
         [0034]     It is the primary object of the present invention to provide safety restraint assemblies for vehicles which include buckle and latch plate mechanisms which can not be released by inertial forces applied to the components of the assemblies such as caused by vehicle accidents including rollovers.  
         [0035]     It is a further object of the present invention to provide latching and locking mechanisms for seat belt restraint systems which follow Newtonian Laws of Physics to the effect that for every action, there is an equal and opposite reaction, so that a latch plate can not be released relative to a buckle unless oppositely directed forces are applied to a pair of opposing push buttons associated with the restraint systems.  
         [0036]     It is also an object of the present invention to provide latching and locking mechanisms for seat belt restraint systems wherein the inadvertent or accidental application of force to one of a pair of release push buttons associated therewith can not cause the release of latch plates of the restraint systems and further wherein such accidentally application of force supplies a greater force to retain the other of the release buttons in a locked position.  
         [0037]     It is yet a further object of the present invention to provide non-inertial release restraint buckles for use in seat belt restraining systems of the type utilized in automotive vehicles and the like wherein the buckle latching assemblies can be structured from a minimal number of operative components to thereby reduce a risk of component failure while decreasing manufacturing costs of the restraint buckles.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0038]     A better understanding of the invention will be had with respect to the embodiments disclosed and with reference to the attached drawings wherein:  
         [0039]      FIG. 1  is a perspective illustrational view of a first embodiment of the present invention shown with the buckle housing removed and wherein the latch plate is connected to a conventional seat belt with the buckle being connected to a conventional anchor belt;  
         [0040]      FIG. 2  is a view similar to  FIG. 1  showing the latch plate of the first embodiment detached from the buckle housing;  
         [0041]      FIG. 3  is a top plan view showing the latch plate of the embodiment of  FIG. 1  connected to the frame of the buckle and with the housing removed;  
         [0042]      FIG. 4  is a view taken from the right side of the latch plate and buckle frame of  FIG. 3 ;  
         [0043]      FIG. 5  is a front plan view of the latch plate and buckle frame of  FIG. 3 ;  
         [0044]      FIG. 6  is a rear elevational view of the buckle frame and latch plate shown in  FIG. 3 ;  
         [0045]      FIG. 7  is a cross-sectional view taken along line  7 - 7  of  FIG. 4 ;  
         [0046]      FIG. 8  is a cross-sectional view taken along line  8 - 8  of  FIG. 4 ;  
         [0047]      FIG. 9  is a cross-sectional view taken along line  9 - 9  of  FIG. 3 ;  
         [0048]      FIG. 10  is a cross-sectional view taken along line  10 - 10  of  FIG. 3  showing the release push bottons in a first outer locking position;  
         [0049]      FIG. 11  is a view taken along line  10 - 10  of  FIG. 3  illustrating the release push buttons being simultaneously engaged to permit release of the latch plate from the buckle frame;  
         [0050]      FIG. 12  is a cross-sectional view taken along line  12 - 12  of  FIG. 11 ;  
         [0051]      FIG. 13  is a cross-sectional view taken along line  10 - 10  of  FIG. 3  illustrating the movement of one push button toward a release position while the other push button is urged to a tighter locked position;  
         [0052]      FIG. 14  is a perspective illustrational view of a second embodiment of the present invention connected to a seat belt and anchor belt of a conventional vehicle wherein the buckle housing is shown surrounding the buckle frame and having opposite recesses in which the opposing push bottons are seated;  
         [0053]      FIG. 15  is an illustrational view similar to  FIG. 14  except showing the latch plate of the second embodiment released from the buckle housing;  
         [0054]      FIG. 16  is a top plan view of the second embodiment of the invention showing in dotted lines the recessed side walls of the buckle housing in which the push buttons are protectively seated;  
         [0055]      FIG. 17  is a right side view of the embodiment shown in  FIG. 14 ;  
         [0056]      FIG. 18  is a front elevational view of the embodiment shown in  FIG. 14 ;  
         [0057]      FIG. 19  is a rear elevational view of the embodiment shown in  FIG. 14 ;  
         [0058]      FIG. 20  is a cross-sectional view taken along line  20 - 20  of  FIG. 17 ;  
         [0059]      FIG. 21  is a cross-sectional view taken along line  21 - 21  of  FIG. 16 ;  
         [0060]      FIG. 22  is a cross-sectional view taken along line  22 - 22  of  FIG. 16 ;  
         [0061]      FIG. 23  is a cross-sectional view taken along line  23 - 23  of  FIG. 16 ;  
         [0062]      FIG. 24  is a cross-sectional illustrational view taken along line  22 - 22  of  FIG. 16  showing the simultaneous movement of the release push buttons from a first lock position to a second release position;  
         [0063]      FIG. 25  is an illustrational view taken along line  21 - 21  of  FIG. 16  showing the latch plate released from the buckle housing;  
         [0064]      FIG. 26  is a view taken along line  22 - 22  of  FIG. 16  showing how the push buttons cannot be accidentally engaged to a release position because they are recessed within the side walls of the buckle housing; and  
         [0065]      FIG. 27  is a cross-sectional view taken along line  27 - 27  of  FIG. 26  but showing push button  225  being pushed in to release one latch thereby causing the opposite latch to be forced into tighter engagement with the latch plate to prevent its release. 
     
    
     DETAILED DESCRIPTION  
       [0066]     With continued reference to  FIGS. 1-13  of the drawing figures, a first embodiment of non-inertial release restraint buckle of the present invention will be described as used with a seat belt restraint system of a vehicle. Such a restraint system includes a seat belt  50  in the form of a harness or lap belt which is mounted to a latch plate  51  for insertion into a buckle  48 . The buckle includes a housing  52  which is connected by way of a buckle housing frame member  53  to an anchor belt  54  which is normally connected to an anchor bracket which is bolted to a frame of the vehicle.  
         [0067]     The buckle housing  52  has been removed to show the inner workings of the buckle and latch plate in  FIGS. 1 and 3 - 13 , however, the housing is shown in  FIG. 2  with respect to the first embodiment and is also shown in all figures with respect to a second embodiment in  FIGS. 14-27 . As is illustrated in  FIG. 2 , to release the latch plate  51  from the buckle  48 , simultaneous forces must be applied to the opposing release push buttons  56  and  58  associated therewith.  
         [0068]     In the first embodiment showing in  FIGS. 1-13  the latch plate  51  includes an opening  60  for purposes of receiving a locking or latching mechanism as will be described in greater detail hereinafter. Forwardly of the opening  60  are a pair of spaced tangs  61  and  62  each having beveled inner surfaces  63  and  64 , respectively, see  FIG. 7 , which taper inwardly from a front of the latch plate to an enlarged opening  67  between the tangs. The tangs form opposing locking catch hooks  65  and  66  which function to provide a secondary locking function when the latch plate is fully inserted within the buckle housing, as will be described. It should be noted that the opening  60  is spaced rearwardly of an inner edge  68  of the opening  67 . The latch plate  51  further includes a base portion  69  which is somewhat enlarged compared to the leading tang portion and which includes slots  70  for receiving the seat, lap or harness belt  50 .  
         [0069]     The buckle housing  52  has an opening  71  in one end thereof for receiving the latch plate. The opening communicates with opposing channels or passages  72  formed by the buckle frame member  53  in which the latch plate is slidingly received when inserted into the buckle housing.  
         [0070]     Mounted within the housing  52  is a single latch  74  which is movably mounted at its base  75  within a lip  73  of the buckle frame, see  FIG. 8 . A lock or latch dog  76  is provided generally centrally of the latch, and extends outwardly from a plane of the base of the latch. The latch is movable from a first locking position, wherein in the latch dog is positioned so as to engage within the opening  60  of the latch plate, see  FIGS. 1, 2 ,  7  and  9 , to a second release position wherein the latch and latch dog  76  is pivoted away from the channels  72  to permit the insertion and withdrawal of the latch plate  51 , see  FIG. 12 . Extending forwardly of the latch dog  76  are a pair of latch control arms  77  and  78  which are spaced on either side of the latch dog. The control arms are connected by a forward connector element  79  such that the arms  77  and  78  are rigidly secured relative to one another.  
         [0071]     The latch  74  is continuously urged to its first locking position by a leaf spring or other resilient element  80 , as is shown in  FIG. 9 . When the latch plate  51  is inserted within the channels  72  of the buckle housing  52 , the latch plate will engage the lock dog  76  and cam the latch  74  to its second release position. Once the opening  60  passes the leading edge of the lock dog  76 , the spring  80  will urge the latch dog into the opening  60  to thereby prevent withdrawal of the latch plate  51  with the latch dog  76  engaging an edge  81  at the forward portion of the opening  60 . This action provides a first and primary locking function for retaining the latch plate within the buckle.  
         [0072]     Also provided within the housing  52  is a portion of the buckle frame  53 . The frame generally includes a base portion  82  which is fixedly secured to a lower wall of the housing  52 . The frame includes a pair of side openings  83  and  84  formed in opposite sidewalls  85  and  86  thereof. The sidewalls  85  and  86  have inwardly extending flanges  87  and  88  associated therewith which extend inwardly of the housing and thereby define the channels  72  for guiding the latch plate within the buckle.  
         [0073]     To control the release of the latch  74 , the present embodiment of the invention utilizes the pair of oppositely oriented and opposing release push buttons  56  and  58 . The push buttons are slidably mounted on opposing tracks  89 ,  90  and  91 ,  92  defined in the flanges  87  and  88 , respectively, of the sidewalls of the frame so as to movable within the openings  83  and  84  in the sidewalls  85  and  86  of the buckle frame.  
         [0074]     Each of the push buttons  56  and  58  are generally similarly configured but are mirror images of one another. The push buttons include concave finger engaging outer surfaces  93  which extend generally flush with or slightly within recessed sidewall openings  94  and  95  of the housing  52 . The housing  52  and openings  94  and  95  are illustrated in dotted line in  FIG. 3 . The recessed sidewalls of the buckle housing are better shown in  FIGS. 14, 16  and  17  with respect to a second embodiment of the invention. The push buttons further include a pair of spaced closed slots  101  and  102  which are of a size to be slidingly received on the spaced guide tracks  89 ,  90  and  91 ,  92 .  
         [0075]     With reference to  FIG. 7 , each push button also includes an open slot  104 ,  105  which extends along a full length of the push button in which one of the tangs of the latch plate is slidingly received when the latch plate is inserted within the buckle housing. The push button  56  includes the slot or channel  104  for receiving the tang  61  of the latch plate. Push button  58  includes slot  106  for receiving tang  62 . As previously described, each tang includes an inner beveled surface. Latch plate tang  61  includes a beveled surface  63  which engages against a side edge  106  defining one side of an opening into the slot  104  of the push button  56 . In this manner, when the latch plate is inserted within the buckle housing  52 , the latch plate tang  61  will engage within the slot  104  with the cam surface  63  thereof urging the push button inwardly of the housing by engagement with the wall or edge  106 , thus moving the push button  56  into the buckle housing. When the tang member is fully seated, the hook  65  of the tang  61  engages within an opening  107  in an inner end wall of the push button  56  and thereby provide a secondary locking function to retain the latch plate in the buckle housing. In a like manner, the beveled portion  64  of the tang  62  engages a wall  108  of push button  58  as the latch plate is inserted within the buckle housing. Contact of the latch plate with push button  58  urges the button inwardly of the housing until the hooked end  66  of tang  62  seats in an opening  109  in an inner wall of push button  58  to thereby further lock the latch plate within the housing.  
         [0076]     The seating of the latch plate tangs in the openings in the push buttons occurs simultaneously with the seating of the latch dog  76  within the opening  60  in the latch plate  51 . Thus, there are three separate points of engagement of the latch plate with the components of the buckle. Further, proper alignment of the latch plate is assured by the edge  68  of the latch plate engaging the front face of the push buttons when in the locked position as shown in  FIG. 7 .  
         [0077]     The movement of the push buttons  56  and  58  to their first or outer locking position, as shown in  FIGS. 7 and 10 , is accomplished by a spring or similar resilient element  110  which is mounted within recessed seats  111  and  112  formed in the inner walls  113  and  114  of the opposing push buttons. The spring ensures that an equal and opposite force is applied to urge each of the push buttons to their first, outer locking position. The connection of the spring  110  further ensures that if a force is applied to one of the push buttons alone, to move the one push button from its first outer locking position to an inner release position, an increased force is applied by the compression of the spring  110  to urge the opposite push button more tightly into its first locking position. It is this equal and opposite application of force, based upon Newtonian Laws of Physics, which makes the lock mechanism of the present invention failsafe and not subject to premature release by inertial forces which can be caused during vehicle accidents. More specifically, any force applied to one push button to release it, without an opposite force being applied to the opposing push button, can not result in the unlatching of the latch  74  or a release of the latch plate tangs from both release push buttons.  
         [0078]     To control the release of the latch  74 , each push button has an opening  104 ′,  105 ′ along the full width thereof which communicate with the slots  104 ,  105 , respectively, in which the arms  77  and  78  of the latch are received. As shown in  FIG. 10 , when the latch is in its locked position, each arm  77  and  78  is seated on pairs of outwardly extending catches or shoulders  121  and  122  of the push buttons  56  and  58  and thus, the latch can not be moved downwardly to its second unlocked or release position. However, each push button includes a  27 . beveled wall  124 ,  125  opposing the catches  121  and  122  such that when the push buttons are urged inwardly of the buckle housing, toward their release position, see  FIG. 11 , the arms of the latch are free of the catches so as to be engageable by the beveled surfaces  124 ,  125  which thereby urge the latch arms to move the latch to its second release position against the influence of the spring  80 . In the second position of the latch, the latch plate may be easily withdrawn from the buckle housing as the tangs and latch dog are simultaneously release from the push buttons and latch plate, respectively.  
         [0079]     Although not specifically shown in the drawing figures, it is possible that a separate spring element may be utilized in association with the latch plate frame of the present invention in order to provide a discharge force for further facilitating the removal of the latch plate from the buckle housing. Examples of such ejection mechanisms are described in applicant&#39;s prior U.S. Pat. No. 6,539,595 issued Apr. 1, 2003, the entire contents of which are incorporated herein by reference.  
         [0080]     From the foregoing description, it should be noted that each push button  56  and  58  supports a separate one of the arms  77  and  78  of the latch. Therefore, both push buttons must be moved to their release positions to release each of the arms  77  and  78  in order that the latch can be moved to its second or release position by a force of engagement of the beveled walls or surfaces  124 ,  125  associated with the push buttons. The premature movement of either push button alone, as shown in  FIG. 13 , will only cause the catches  121 ,  122  of the associated push button to release, one of the latch arms but will not release the opposing arm of the latch which is retained locked by the catches of the opposing push button. In  FIG. 13 , push button  56  is engaged with an object “J” which applies a force to urge the push button to its release position wherein latch arm  77  is released from catches  121 . However, the spring  110  applies an increased force against push button  58  to maintain latch arm  78  locked within the catch  122 . Therefore, both push buttons must be moved inwardly of the buckle housing, simultaneously, as shown in  FIG. 11  in order to cause a release of the latch plate.  
         [0081]     To further guide the push buttons  56  and  58  of the present embodiment in their sliding movement between their outer locked position and their inner release positions, a guide block  126  is secured to the buckle frame  53 . The block includes a depending flange  127  which extends over a top portion of each push button as shown in  FIGS. 3, 4  and  9 .  
         [0082]     With particular reference to  FIGS. 14-27 , a second embodiment of the invention is disclosed in greater detail. In this embodiment, the non-inertia release restraint buckle assembly  200  is shown as including a latch plate  201  which is connected to a conventional seat belt, lap belt or restraint harness  50  in a manner similar to that disclosed with respect to the first embodiment. Likewise, the buckle assembly includes an outer frame member  202  having an opening  203  therein for receiving an anchoring strap  54  which is connected to a bracket or otherwise secured to the frame of a vehicle.  
         [0083]     In this embodiment, the latch plate  201  includes an opening  205  for cooperating with a pair of latches  206  and  207  which are movably mounted at  208  and  209  within a buckle housing  210 . Each of the latches  206  and  207  includes at least one and preferably two spaced outwardly extending latch dogs  212  and  213 , respectively. As shown in the drawing figures, the pairs of latch dogs are structured to fit in an interdigitated manner within the opening  205  in the latch plate when the latch plate is fully seated within the housing  210 . In this manner, both latches  206  and  207  must be moved from their first locking position, as shown in  FIG. 21 , to a second release position, as shown in  FIG. 25 , in order to permit the insertion or removal of the latch plate  201  from the buckle housing  210 . To ensure that each of the latches  206  and  207  is normally urged to its first locked position, each is resiliently urged by a leaf or other resilient or spring element  215  and  216 , respectively, toward the locked position.  
         [0084]     As with the previous embodiment, the housing has an opening  220  at one end thereof which communicates with a channel  221  defined between the latches  206  and  207  in which the latch plate  201  is slidingly receivable when inserted within the housing  210 . As the latch plate  201  is inserted within the housing, the leading edge  222  thereof will engage cam like surfaces on the back of each latch dog thus pushing the latches  206  and  207  outwardly away from the channel  221  and permitting the latch plate to be fully inserted until such time as the latch dogs snap into engagement within the opening  205  in the latch plate to thereby lock the latch plate in position within the housing  210 .  
         [0085]     The present embodiment of the invention operates under the same laws of Newtonian Physics as the first embodiment in that, in order to release the latch plate  201  from the buckle housing  210 , force must be applied to two opposing release or push buttons  225  and  226  which are mounted to extend outwardly through two spaced recessed openings  227  and  228  in opposite sidewalls  229  and  230  of the buckle housing  210 .  
         [0086]     As opposed to using a single resilient or spring element between the push buttons as disclosed with respect to the previous embodiment, in the present embodiment, a pair of spaced springs  232  and  233  are mounted within the housing so as to be supported within seats  234  and  235  of the push buttons  225  and  226 , respectively. The opposite ends of the springs  232  and  233  are seated within seats  240  and  241  which are provided within generally u-shaped catches  242  and  243  of each of the opposite push buttons  225  and  226 , respectively.  
         [0087]     With specific reference to  FIG. 22 , push button  225  has an extension portion  250  which integrally connects the push button to its inner unshaped catch  242 . The u-shaped catch engages a spaced or remote edge of the latch  206  to thereby retain the latch in its first or locked position. The latch  206  further includes a beveled or cam surface  251  which opposes a camming surface  252  of the push button  225  such that, when the push button  225  is pushed inwardly towards its second release position, the catch  243  will release one edge of the latch  206  and the camming surface  252  of the push button will move the latch, by engagement with its surface  251 , to its second release position. However, even if the latch  206  is moved to its release position, the latch  207  remains engaged with the latch plate unless the push button  226  is pushed inwardly to its second release position.  
         [0088]     Push button  226  also includes an extension portion  255  as shown in  FIG. 26  which extends to its inner catch  243 . The push button also includes a beveled or camming surface  256  which is engageable with a beveled surface  257  associated with the latch  207 , see  FIG. 24 . In this manner, when the push button  226  is pushed inwardly of the housing  210 , the catch  243  will release the latch  207  allowing the two cam surfaces to urge the latch  207  to its outer or second release position.  
         [0089]     As each of the push buttons  225  and  226  are depressed inwardly of the housing, the springs  232  and  233  associated therewith will apply an increased force against the opposing push button. Therefore, any force applied to one of the push buttons to push it inwardly of the housing to its second release position will result in an increased force being applied to maintain the opposing push button in its first or outermost locked position. Thus, to release the latch plate, opposite forces must be applied to the opposing push buttons, as shown in  FIG. 24 , in order to effect a release of the latch plate  201  from the buckle housing. As soon as the latch plate has been removed from the buckle housing and the push buttons released, the springs  233  and  232  will urge the push buttons to their outer or first locked position and the springs  215  and  216  will automatically cause the latches  206  and  207  to move to their first locking positions.  
         [0090]     In the operation of the second embodiment, upon insertion of the latch plate  201 , the latches  206  and  207  will be cammed away from one another by the leading edge  222  of the latch plate engaging the cam surfaces of the lock or latch dogs  212  and  213  until such time as the latch dogs snap into the opening  205  to lock the latch plate within the housing. Thereafter, should any inadvertent force be applied to the buckle, its housing or elements causing an inadvertent depression of one of the push buttons, such inadvertent depression, which may be caused by movement of the belt buckle during an accident, will not effect a release of the latch plate. In  FIG. 27 , push button  225  is shown as being accidentally moved to its release position thereby releasing latch  206  from the catch  242 . However, when moved to this position, the spring  232 , see  FIG. 20 , will apply an increased force on the opposing push button  226  thereby ensuring that the opposing push button is maintained in its locked or outer position preventing release of the catch  243  from latch  207 .  
         [0091]     Only upon application of simultaneous forces to the opposing latch buttons  225  and  226  in opposing directions, as shown in  FIG. 24 , can the latch plate  201  be released from its locked engagement with the latches  206  and  207 .  
         [0092]     With particular reference to  FIGS. 14, 16   17  and  26 , the buckle housing  210  is specifically designed and configured to prevent accidental contact with the push buttons  225  and  226  which could lead to an inadvertent actuation of the buttons to move them toward their release positions. Each sidewall  229  and  230  is recessed inwardly as shown in dotted line in  FIG. 16  at  260  and  261 , respectively, such that the openings  227  and  228  for the push buttons are recessed inwardly of the outer portions of the sidewalls. As shown, the outer engageable portions of each push button are thus slightly recessed relative to the outer portions of the sidewalls when in their outermost, first locking position, thereby preventing their accidental depression, as is illustrated in  FIG. 26 . As shown in  FIG. 26 , should a sidewall of the buckle housing engage a surface of object “J”, the release buttons will not be depressed due to their inset position or mounting relative to the outer portions of the sidewalls. The same recessed features are provided for the buckle housing and push buttons of the embodiment of  FIGS. 1-13 .  
         [0093]     The foregoing description of the preferred embodiment of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiment illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the following claims and their equivalents.