Abstract:
A method and apparatus for providing a mechanical seal between two objects is provided. The mechanical interface including a protrusion located on a first component; and a pair of cantilevered beams located on a second component, wherein the pair of cantilevered beams are forced outwardly on opposite sides of the protrusion when a tab portion of the second component is received in an opening of the first component. The method of including the steps of: forcing a pair of cantilevered beams located on a second component outwardly from opposite sides of the protrusion when as a tab portion of the second component is received in an opening of a first component.

Description:
BACKGROUND 
       [0001]    This application claims priority under 35 U.S.C. §119 to the following Chinese Patent application no. CN 201410584901.X, filed Oct. 27, 2014, the entire contents of which are incorporated herein by reference thereto. 
         [0002]    Various embodiments of the present invention relate to an actuator for a vehicle latch and more particularly, a mechanical seal between a housing and a cover of the actuator and a method for providing a seal between a housing and a cover of the actuator. 
         [0003]    In some applications, latches are required to perform numerous operations within limited confines of an application area of the item they are installed in. Still further, some latches include motorized actuators for performing some of these operations. 
         [0004]    An actuator may have a housing with a cover configured to be secured to the housing. Due to the environments the actuator is located in it is desirable to have a good seal between the cover and the housing of the actuator. In order to protect the internal components of the actuator from moisture and/or debris. While an actuator is mentioned above it is also understood that it is also desirable to provide a good seal between a cover and a housing of a latch for a vehicle latch, that may or may not have an actuator secured thereto. 
         [0005]    One method for providing a seal between the cover and the housing of an actuator is to locate an elastomer in between edges of the cover and the housing that are adjacent to each other when the cover is secured to the housing. However and in order to provide a suitable seal, a compressible elastomer must be used in order to provide a separation force between the cover and the housing. In addition the elastomer must also be capable of deforming such that it fills the gaps in between the two components (e.g., cover and housing) due to imperfections in the mating of the components. 
         [0006]    An alternative method of sealing a plastic cover to a plastic housing is achieved through a welding process such as ultrasonic welding or laser welding. However, the ultrasonic welding process requires an extra component or portion for use as the staking in the welding process, which can be pre-molded or extruded in place. The laser welding process on the other hand, requires the use of expensive equipment, which may also be labor-intensive. 
         [0007]    Accordingly, it is desirable to provide an improved seal between the housing and the cover of an actuator or latch for a vehicle latch. 
       SUMMARY OF THE INVENTION 
       [0008]    In one embodiment, a mechanical interface for securing two objects together is provided. The mechanical interface comprising: a protrusion located on a first component; a pair of cantilevered beams located on a second component, wherein the pair of cantilevered beams are forced outwardly on opposite sides of the protrusion when a tab portion of the second component is received in an opening of the first component. 
         [0009]    In another embodiment, an assembly is provided. The assembly, having: a first component having a protrusion, the protrusion extending about a periphery of the first component; a second component having a pair of cantilevered beams, the pair of cantilevered beams extending about a periphery of the second component each of the cantilevered beams being configured for interaction with the protrusion of the first component when the second component is secured to the first component, wherein each pair of cantilevered beams are forced outwardly on opposite sides of the protrusion when a plurality of tab portions of the second component are received in a respective opening of a plurality of openings of the first component. 
         [0010]    In yet another embodiment, a method of providing a mechanical interface between two objects together is provided. The method including the steps of: forcing a pair of cantilevered beams located on a second component outwardly from opposite sides of the protrusion when as a tab portion of the second component is received in an opening of a first component. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    These and/or other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
           [0012]      FIG. 1  is a perspective view of an actuator in accordance with an embodiment of the invention; 
           [0013]      FIG. 2  is a bottom view of the actuator housing in accordance with an embodiment of the invention; 
           [0014]      FIG. 3  is a cross sectional view of a portion of the actuator in  FIG. 1  along line  3 ; 
           [0015]      FIG. 3A  is a view of the mechanical seal between the actuator housing and cover in accordance with an embodiment of the present invention; and 
           [0016]      FIG. 4  is a schematic illustration of an actuator secured to a latch. 
       
    
    
       [0017]    Although the drawings represent varied embodiments and features of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to illustrate and explain exemplary embodiments the present invention. The exemplification set forth herein illustrates several aspects of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION 
       [0018]    Referring now to the FIGS., an actuator  10  is illustrated. In one embodiment, the actuator  10  is configured for use in or with a latch or vehicle latch  11 , wherein a motor of the actuator drives a worm and the worm is operatively coupled to a gear, which when driven drives components of the vehicle latch the gear is also operatively coupled to. In one embodiment, the actuator  10  has a housing or housing portion or first component  12  and a cover or cover portion or second component  14 . In one embodiment the housing  12  and cover  14  may be made out of plastic such as polypropylene in order to provide a seal between the housing  12  and the cover  14 . 
         [0019]    In the illustrated embodiment, the housing  12  has a plurality of openings  16  each of which has a complementary ledge portion or feature  18  located proximate to the opening  16  for engagement with a tab portion  20  of the cover  14 . Tab portion  20  is configured such that when cover  14  is secured to housing  12  (e.g., the cover  14  moves in the direction of arrow  22  in  FIG. 3  with respect to housing  12 ) the tab portion  20  passes by ledge portion or feature  18  internally until an end  24  of tab portion  20  contacts an end  26  of ledge portion or feature  18  such that tab portion  20  is now retained within an opening  16 . 
         [0020]    At the same time a pair of cantilevered beams  28  of the cover  14  engage a protrusion  30  of the housing  12  in order to provide a seal between the two components  12  and  14 . As discussed, above it is desirable to provide such as seal in order to protect the internal components of the actuator from moisture and/or debris. Protrusion  30  is configured to have a triangular or conical shape such that sloped surfaces  32  of protrusion  30  contact cantilevered beams  28  as the cover  14  moves in the direction of arrow  22  with respect to housing  12 . This interaction (e.g., cantilever beams  28  contacting protrusion  30 ) causes the cantilevered beams  28  to move outwardly from protrusion  30  in the direction of arrows  34  such that a good seal between cover  14  and housing  12  is provided. The seal being formed mechanically from the components of the actuator (e.g., housing  12  and cover  14 ) such that no additional components (e.g., elastomeric member) are required for a seal. It being understood that the material (e.g., plastic or other equivalent material) used for cover  14  and thus cantilevered beams  28  has resilient characteristics (e.g., capable of being deflected from an original state and then springing back towards its original state) such that the cantilevered beams  28  can move or be deflected outwardly from protrusion  30  in the direction of arrows  34  as the beams  28  contact protrusion  30  and once the cover  14  is secured to the housing  12  (e.g., tab portions  20  engage features  18 ) the resilient characteristics of the cantilevered beams  28  apply a force in a direction opposite to arrows  34  to protrusion  30  which in turn causes the reactionary force upward in the direction of arrow  36  to be generated and thus create a tight seal as ends  24  of tab portions  20  contact the surfaces  26  of features  18  and beams  28  contact protrusion  30 . 
         [0021]    In addition and in one embodiment, the two cantilevered beams  28  of the cover  14  extend completely around a periphery of the cover  14  for interaction with a corresponding protrusion  30  that extends completely around a periphery of the housing  12  such that a seal is formed by the beams  28  and protrusion  30  each of which extends completely around the perimeter or the interface of the two parts to provide a seal. Alternatively and in another embodiment, the two cantilevered beams  28  and the protrusion  30  may only extend around a portion of the periphery of the housing  12  and the cover  14  in order to provide the mechanical seal in localized areas of the housing  12  and cover  14  of the actuator  10 . Still further and in yet another alternative embodiment, the two cantilevered beams  28  and the protrusion  30  may only extend around separate portions of the periphery of the housing  12  and the cover  14  in order to provide mechanical seals (e.g., more than one) in localized areas of the actuator. 
         [0022]    In other words, and as the cover  14  is secured to housing  12 , the cantilevered beams  28  first contact protrusion  30  prior to tab portion  20  being fully seated in opening  16  (e.g., end or end portion  24  of tab portion  20  contacting end or end portion  26  of ledge or feature  18 ) such that the cantilevered beams  28  must be deflected outwardly in the direction of arrows  34  prior to tab portion  20  being fully received within opening  16  and engaging ledge or feature  18 . 
         [0023]    In addition, the interaction of protrusion  30  with cantilevered beams  28  also creates a reactionary force in the direction of arrow  36  to keep tab or tab portion  20  engaged with ledge or feature  18  of opening  16 . 
         [0024]    Another added benefit of the use of cantilevered beams  28  is that a greater amount of surface area is provided (e.g., cantilever beams contacting opposite sides of protrusion  30 ) which increases the contact area and aids in the sealing function. 
         [0025]    As such, a mechanical seal between the actuator housing and cover is provided using only the material of the mating components, in this case the housing  12  and the cover  14 , which as described above may be made out of plastic material such as polypropylene in order to seal the assembly. Although a specific example of an actuator assembly (e.g., housing and cover) is illustrated, it is understood that various embodiments of the present invention may be applicable to any type of assembly wherein a housing is configured to have a cover secured thereto with a mechanical interface such as the one described and disclosed herein wherein a mechanical seal is provided between the materials of the mating components. 
         [0026]    As described herein one exemplary embodiment of the present invention consists of creating two cantilever beams  28  that deform when the cover  14  is assembled with the housing  12 . The housing  12  has a triangular shape  30  that pushes the two cantilever beams  28  away from each other. This deformation creates a natural reaction force between the triangular shape  30  and the cantilever beams  28  and this force provides the same function as the elastomer deformation. In addition, the triangular shape  30  also increases the contact area and aids in the sealing function. 
         [0027]    In addition, it is also understood that a plurality of contact areas comprising, pairs of cantilevered beams  28  and protrusion  30 , are located around the interfacing surfaces of the cover  14  and the housing  12 . In other words, a plurality of interfaces  38  are provided to secure the cover  14  to the housing  12 , wherein the interfaces  38  comprise at least a pair of cantilevered beams  28  and a protrusion  30  as well as a tab portion  20  and ledge or feature  18  proximate to opening  16 . 
         [0028]    Various embodiments of the present invention provide cost savings to existing means for sealing and securing two components together as the number of components required to seal the cover to the housing of the actuator are eliminated. For example, the elastomeric seal is now no longer required since it is replaced with the interfaces  38  which include cantilevered beams  28  and protrusion  30 . Accordingly, an actuator with such a mechanical seal provides a competitive and cost efficient design. 
         [0029]    As used herein, the terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. In addition, it is noted that the terms “bottom” and “top” are used herein, unless otherwise noted, merely for convenience of description, and are not limited to any one position or spatial orientation. 
         [0030]    The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., includes the degree of error associated with measurement of the particular quantity). 
         [0031]    While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.