Abstract:
A detent system particularly suitable for pivotal automotive windows, but not limited to such use, wherein the components are molded of a synthetic material and wherein a first member pivotally supports a second member and the second member is pivotally positioned between detent maintained positions. The detent action is achieved by shaping and sizing the relative members such that deformation between the relative members occurs during relative rotation such that the changing resistance to relative rotation, because of the interlocking configuration of the members, a detent action is achieved.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention pertains to latches having relatively rotatable members wherein a detent action for locking the members in relative relationship is achieved by resilient deformation of one, or both, of the members.  
           [0003]    2. Description of the Related Art  
           [0004]    Many of the pivotally mounted windows in contemporary automobiles, vans and trucks, particularly the rear side windows of truck cabs, or sun roof panels, utilize a latch which permits the associated unhinged edge of the window to be partially opened for ventilation purposes. By the partial pivotal opening of such windows, and as the rearward window edge is open, a venturi effect is produced which pulls air through the vehicle passenger space, and reduces the entry of rain into the cabin. Such latches normally pivot between a fully open position and a fully closed position causing the window or glass panel to seat against resilient sealing structure.  
           [0005]    Conventionally, such window latches basically consist of a pivotal first member which is of such shape as to function as a handle, and a second member pivotally mounted to the first member having a link extending therefrom.  
           [0006]    In the fully open position of known latches of this type, an over-center relationship of the window link is usually used to hold the window closed in that the latch structure is in its retracted or closed position. When the latch structure is in its open or extended position, an over-center link relationship may also be used, but in many instances, various types of detent knobs or projections are employed. Examples of such types of window latches are shown in U.S. Pat. Nos. 4,466,644 and 4,469,370.  
           [0007]    It is desirable to produce molded synthetic plastic latch members which are capable of a long effective life for holding window or glass panels in closed and open positions, and the invention deals with improved constructions for window latches which are easy to operate, effectively hold the window in desired positions, and inexpensive to manufacture and assemble.  
         OBJECTS OF THE INVENTION  
         [0008]    It is an object of the invention to provide a latch having detent maintained operative positions which is molded of a synthetic material, is self-lubricating, and does not require secondary machining operations.  
           [0009]    Another object of the invention is to provide a latch system formed of resilient molded thermoplastic members relatively pivotal to each other wherein such pivotal movement is releasably locked or positioned by resilient detent structure built into the configuration of the members.  
           [0010]    An additional object of the invention is to provide a latch system including a pair of molded synthetic members pivotally related to each other wherein the pivoting action is self-lubricating, a releasable detent action is achieved at predetermined pivotal relationships between the members, and the members may be inexpensively manufactured.  
         SUMMARY OF THE INVENTION  
         [0011]    Basically, a latch detent system in accord with the inventive concepts includes two members pivotally interconnected for relative rotational movement. While it would be possible to practice the inventive concepts with the detent latch system members being formed of any resiliently deformable material, such as steel or aluminum, preferably, the members are molded of a high strength synthetic self-lubricating material which would usually be of a thermoplastic nature, such as nylon, acetal or polyacetal.  
           [0012]    The first member may be designated the handle and supports the second member which is rotatable received within spaced sockets defined in the first member. The second member also has a link extending therefrom whose length is transversely related to the length of the second member.  
           [0013]    The first member will usually be of a handle form which is easy to grasp and push against. Usually, the first member will include a flat portion against which the palm may be applied, and a pair of spaced supports are defined on the first member. These supports are parallel to each other and resiliently deformable away from each other to a limited extent. Preferably, the supports each include a blind socket defined by a non-circular circumference, and a bottom surface. An elongated U-shaped recess is formed in each socket bottom surface generally diametrically related to the associated socket.  
           [0014]    The second member is of an elongated configuration having axially extending end portions and terminating ends and surfaces. The end portions are of a non-circular peripheral configuration complementary in shape to the socket wall configurations so that the end portions may be closely received therein. Preferably, the second member end portions are of a generally elliptical configuration complementary to the generally elliptical configuration of the first member sockets.  
           [0015]    The second member end portions are preferably of a general C-shaped transverse cross sectional configuration capable of being deformed inwardly, but could be of a closed elliptical shape. Also, the second member end terminating surfaces are formed with elongated projections complementary in configuration to the elongated recesses defined in the first member socket bottom surfaces, and are of a generally U-shaped transverse sectional configuration.  
           [0016]    A link integrally extends from the second member having a length generally perpendicular to the length of the second member, and includes connecting structure at its end for attachment to window hardware. Preferably, the link is homogeneously formed of the same material as the second member.  
           [0017]    The first and second members are assembled by deforming the first member supports away from each other sufficiently to permit the second member end portions to be received within the sockets of the supports. Once the second member is in place and aligned with the first member sockets, the first member supports are permitted to return to their natural position which encases the second member end portions within the sockets and the second member terminal end surfaces will be in engagement with the socket bottom surfaces. Preferably, in order to prevent mistakes during assembly, the diametrical dimensions of one of the first member sockets and one of the end portions of the second member are slightly greater than the other socket and the other end portion preventing erroneous assembly of the first and second members.  
           [0018]    With the first and second members assembled as described above, relative pivoting of the second member to the first member is possible. The sockets are coaxial, as are the end portions, and relative pivoting of the second member relative to the first member causes the second member end portions to be radially inwardly deformed due to the non-circular configuration of the sockets&#39;circumferences. This produces a resistance to relative rotation of the first and second members, but once sufficient rotation has occurred so that the end portions of the second member are permitted to expand, a detent relationship between the first and second members is produced.  
           [0019]    It will be appreciated that when using a self-lubricating material to form the first and second members, the frictional rotation of the members would be lubricated, and relative rotation is not difficult to achieve.  
           [0020]    The detent locking action produced by the contraction and subsequent expansion of the second member end portions is augmented by the projections defined on the second member terminating end surfaces aligning with and entering the recesses defined on the first member socket bottom surfaces. This alignment, and reception of the projections into the recesses produces a distinctive snap action or “click”, and indicates to the operator that a locking detent action has occurred. When it is desired to reverse the action of the latch, force is applied to the first member by the operator permitting the projections to slide out of the recesses and again compressing the second member end portions such that resistance to relative pivoting between the first and second member occurs until once again the surfaces of the sockets correspond to the configuration of the second member end portions and a detent locking relationship between the first and second member again occurs.  
           [0021]    In a variation of the invention, radial projections are defined on the exterior of the second member to engage with a deformable portion formed on the first member thereby producing a detent locking relationship between the members. With this embodiment, the second member end surface projections and first member socket bottom surface recesses may also be used, as can the non-circular configuration of the sockets and end portions.  
           [0022]    Preferably, the non-circular configuration of the first member sockets and the second member end portions is of an elliptical or oval shape. However, it will be appreciated that other non-circular configurations will achieve similar results due to the compression and radial inward deformation of the second member end portions. For instance, hexagonal configurations could be used to provide several detent locking relationships during each relative full pivoting action of the first and second members. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]    The aforementioned objects and advantages of the invention will be appreciated from the following description and accompanying drawings wherein:  
         [0024]    [0024]FIG. 1 is a plan assembly view of a latch using the inventive concepts illustrating the window structure to which the latch is attached,  
         [0025]    [0025]FIG. 2 is a perspective underside view of latch first and second members as assembled,  
         [0026]    [0026]FIG. 3 is an end view of the first member,  
         [0027]    [0027]FIG. 4 is an elevational sectional view as taken through the first member of FIG. 3 along Section  4 - 4  of FIG. 3,  
         [0028]    [0028]FIG. 5 is an elevational sectional view taken through the first member along Section  5 - 5  of FIG. 4,  
         [0029]    [0029]FIG. 6 is a perspective view of the second member, per se,  
         [0030]    [0030]FIG. 7 is an end view of a second member of another embodiment of a toggle link,  
         [0031]    [0031]FIG. 8 is a view of the second member of FIG. 7 as taken from the left thereof,  
         [0032]    [0032]FIG. 9 is an elevational sectional view taken along Section  9 - 9  of FIG. 10,  
         [0033]    [0033]FIG. 10 is an end elevational view as taken from the right of FIG. 9,  
         [0034]    [0034]FIG. 11 is a sectional view similar to the elevational view of FIG. 1 but in section and utilizing the toggle link of FIG. 7, and  
         [0035]    [0035]FIG. 12 is a view of the toggle link association with the window structure as taken along Section  12 - 12  of FIG. 11. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]    With reference to FIG. 1, a detent latch utilizing concepts of the invention is generally indicated at  10 . The window structure  12  mounted upon the vehicle window opening (not shown) is usually formed of a synthetic plastic which closely fits the window opening in a sealed relationship, and includes the V-shaped seal  14 , see FIGS. 1 and 11, which contact the glass window  16  which is pivotally mounted to window structure  12  at a forward location of the window, not shown, as is well known in the automotive art.  
         [0037]    A window anchor  18  is bonded or otherwise attached to the window  16 , and the detent latch structure of the invention is mounted upon the window anchor  18  for pivoting the window  16  from an open position as shown in FIG. 1, to a closed position wherein the window  16  sealingly engages the seal  14 .  
         [0038]    The first member of the latch  10  comprises a handle  20  which is of a generally convex configuration so that the exterior of the handle can be pushed by the palm of the hand, and the edges of the handle extend beyond the handle understructure on the opposite side thereof so that the user&#39;s fingers may grasp the handle to release the latch from its locked position. A toggle link  22  is pivotally mounted upon the handle  20 , as later described, and the handle cover  24  is relatively flat whereby the palm of the hand may be applied against the cover  24  to pivot the latch  10  to its locked condition pivoting the window  16  into engagement with the seal  14 .  
         [0039]    Inside the handle cover  24 , side elements or link supports are shown at  26 , the sides  26  being homogeneously molded of the same material as the handle cover  24 . A pivot bar  28  is formed between the sides  26 , FIGS. 2 and 4, to pivotally receive the window anchor  18 , as is apparent in FIG. 11.  
         [0040]    The thickness of the sides  26  is increased at  30  to define bosses in which bearing sockets  31  for the toggle link  22  are formed. The bearing sockets are each defined by an elliptical surface  32  and a bottom surface  34  perpendicularly disposed to the surface  32 . Accordingly, it will be appreciated that the sockets  31  constitute blind holes and they are coaxially aligned with each other. The elliptical configuration of the socket surfaces  32  will be appreciated from FIG. 4, and as noted in FIG. 5, the coaxial sockets  31  are of a different diametrical dimension for a purpose later explained.  
         [0041]    The bottom surface  34  of each of the sockets  31  is provided with an elongated U-shaped recess  36  which is located in a substantially “diametrical” relation to its associated socket.  
         [0042]    The toggle link body  38  is of an elongated configuration having a large end portion  40  and a smaller end portion  42 , FIG. 6. Each of the end portions terminates in a terminating end  44  perpendicularly disposed to the axis of the body  38 . An elongated U-shaped projection  46  extends from each terminating end surface  44 , and is of a configuration and dimension as to be received within a socket recess  31  when aligned therewith. The toggle body  38 , which constitutes the second member of the detent latch, includes the elongated link arm  48  which is, preferably, homogeneously molded of the material of the body  38 , and the link arm  48  terminates in a C-shaped pin recess  50  for pivotally receiving the pivot pin  52  mounted upon the window structure  12 , FIG. 1.  
         [0043]    The toggle body  38  is of a hollow C-shaped configuration as will be appreciated from FIGS. 6 and 7. This C-shaped configuration of the toggle body  38  permits the toggle body to be inwardly deformed as the synthetic material from which the toggle body is molded is of a relatively rigid elastically deformable self-lubricating material, such as nylon, polyacetal, or the like.  
         [0044]    The handle  20  and the toggle link  22  are preferably assembled by momentarily separating the sides  26  sufficiently to align the toggle body end portions  40  and  42  with the appropriate sockets  31  while the handle  20  is still hot from molding and not fully cured. Upon releasing the sides  26 , the end portions  40  and  42  will be firmly received with the sockets  31 , and as the dimensions and configuration of the socket surfaces  32  are slightly greater than the dimensions of the toggle body end portions  40  and  42 , but of similar configuration, the toggle link  22  will be pivotally attached to the handle  20  in a strong mechanical manner.  
         [0045]    Because the end portion  40  is of a greater diametrical dimension than the toggle body end portion  42 , and because the sockets  31  are of different diametrical dimension to correspond to the toggle body end portions, it is not possible to mistakenly assemble the toggle link  22  to the handle  20  rendering the assembly of these components foolproof.  
         [0046]    When the toggle link  22  is rotated relative to the handle  20  and sockets  31 , the configuration of the sockets, being non-circular, will deform the toggle body  38  end portions inwardly providing a resistance to relative rotation between the handle  20  and the toggle link  22  but once the maximum dimension of the sockets realign with the maximum dimension of the toggle link end portions, the toggle body will expand to its normal configuration providing an indexed detent relationship between the handle  20  and toggle link  22 .  
         [0047]    A further augmentation of the indexed detent relationship between the handle  20  and toggle link  22  is achieved by the reception of the projections  46  defined on the toggle body terminating ends  44  with the recesses  36  defined in the socket bottom surfaces  34 . As the toggle link  22  is rotated relative to the handle  20 , the projections  46  will ride out of the recesses  36  slightly resiliently separating the handle sides or toggle body supports  26  in a resilient manner. Once sufficient relative rotation has occurred, the projections  46  will again align with the recesses  36  permitting the side supports  26  to move inwardly further adding to the locked detent relationship between handle  20  and toggle link  22 , and providing a “click” action capable of being sensed by the operator.  
         [0048]    As the handle  20  and toggle link  22  are pivotally mounted to the window anchor  18  and the window structure  12 , the relative pivoting occurring between the handle  20  and toggle link  22  moves the window  16  between its open and closed positions. The detent operation between the handle  20  and toggle link  22  achieved by the configuration of the socket surfaces  32  and the end portions  40  and  42 , and the interlocking relationship between the projections  46  and recesses  36 , are so related that the window will be held in its open position. Upon pivoting the handle  20  and toggle link  22  in the opposite direction, the window  16  will be brought against the seal  14  to the closed position which will be maintained by the detent action, or if desired, a “over-center” relationship between the pivot bar  28  and pin  52  can be utilized as is well known with this type of latch.  
         [0049]    FIGS.  6 - 12  disclose a variation in the detent action which may be achieved utilizing the inventive concepts, and as much of the structure is similar to the embodiment previously described, common and identical components are referenced by primed numerals.  
         [0050]    In the embodiment of FIGS.  6 - 12 , cams  54  and  56  are defined upon the central region of the toggle body  38 ′. These cams cooperate with a bridge  58  defined on the handle  20 ′ between the sides  26 ′, FIG. 10. The bridge  58  is defined by slots  60  permitting the bridge to be cantilever supported and defined by an edge  62  which, because of the resilient nature of the material of which the handle  20  is formed, is capable of limited movement when engaged by a cam  54  or  56 . Accordingly, the cams  54  and  56  may be so positioned as to augment the detent action achieved by the socket non-circular configuration and the projection and recesses.  
         [0051]    It is appreciated that various modifications to the inventive concepts may be apparent to those skilled in the art without departing from the spirit and scope of the invention.