Abstract:
A fastener includes a male fastener and a cooperating female fastener where the male fastener element is operated by at least one elongated deformable the wall of a compartment and an ed wall with which the male fastener is integrally connected and from which the male fastener forms a projection. For example the elongated deformable wall(s) of the compartment may be deformed by pressure in the compartment so that deformation of the deformable wall deforms the end wall and moves a free end of the projection remote from the wall of the compartment between a latching position and an unlatching position when the deformable wall is deformed.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a male, female fastening system providing an improved operating system for latching and unlatching eh fastener  
         BACKGROUND TO THE INVENTION  
         [0002]    U.S. Pat. No. 5,102,253 issued Apr. 7, 1992 to Pugltest-Conti et al. discloses a snap fit coupling or fastening system wherein fastener elements are provided on the sides of deformable compartments or at the ends of deformable arms and means are provided to directly bend the arm or sidewall on which the fastener element is mounted.  
           [0003]    The pressure at the connection formed by the male and female members of U.S. Pat. No. 5,102,253 is limited to the lowest vacuum, which can be created and thus requires the use of very flexible materials and/or very large assemblies. The hydraulic actuation system of this patent only assists in the dismantling of the connection but can&#39;t be used for the engaging of the fastener system. Furthermore the system is prone to leakage at the interface between the male and the female member of the connection. Another concern with the system of U.S. Pat. No. 5,102,253 is that it applies the actuation force to both the male and the female parts of the connection thereby deforming both. The patent is also limited to the use of snap fit design due to its limited actuation force.  
         BRIEF DESCRIPTIONS OF THE INVENTION  
         [0004]    It is an object of the invention to provide an improved fastener system.  
           [0005]    Broadly the present invention relates to a fastener system comprising a first fastener means and a second fastener means, a male fastener means on said first fastener means and said second fastener means having female fastener for coupling with said male fastener means said first fastener means having a pair of opposed elongated walls and a pair of interconnecting walls interconnecting adjacent ends of said elongated walls to define a compartment, one elongated wall of said pair of elongated walls being deformable by pressure in said compartment, said male fastener means including a projection extending from and integral with said deformable wall and one of said interconnecting end walls so that a free end of said projection remote from said deformable wall moves between a latching position and an unlatching position when said elongated deformable wall is deformed, and means for deforming said first deformable side wall.  
           [0006]    Preferably said first fastener means includes an outer housing, said outer housing being spaced from said elongated walls to provide a pair of free spaces one adjacent to said deformable elongated wall and the other adjacent to said second deformable wall into which said deformable elongated wall and said second deformable wall respectively may be deformed.  
           [0007]    Preferably the other of said pair of opposed elongated walls is also deformable and wherein said male fastener means includes a second projection extending from and integral with the other of said pair of elongated walls so that a free end of said second projection remote from said other deformable wall moves between a latching position and an unlatching position when said other elongated deformable wall is deformed, deformable wall is deformed,  
           [0008]    Preferably said means for deforming acts between said elongated deformable side wall and said second elongated deformable side wall to deform said deformable and said second deformable side walls simultaneously.  
           [0009]    Preferably said means for deforming comprises means for applying fluid under pressure into said compartment. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    Further features, objects and advantageous will be evident from the following detailed description of the invention taken in conjunction with the accompanying drawings in which  
         [0011]    [0011]FIGS. 1 and 2 are transverse cross sections through a simplified version of the fastener showing the fastener in holding (latching) and released positions respectively.  
         [0012]    [0012]FIG. 3 is a simplified isometric view of the fastener element on which the male fastener element(s) is (are) formed.  
         [0013]    [0013]FIG. 4 is a cross section through a fastener employing a single male member and shows the more important dimensions selected to provide a fastener with the desired characteristics such as holding pressure or power showing the fastener holding position.  
         [0014]    [0014]FIG. 5 is a cross section similar to that of FIG. 4 showing the fastener releasing position.  
         [0015]    [0015]FIG. 6 is a cross section similar to that of FIG. 4 showing a slightly modified version of the hinge structure of the fastener. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]    As shown in the drawings the fastener mechanism of the present invention comprises a displaceable male projecting elements that co-cooperates with a female socket  12  into which the projecting male elements are received. Two elements  10  have been shown, as that is the preferred system however only one may be used with a suitable co-operating female element or socket  12 . The following description will be directed primarily to the two-element system The co-operating male  10  and female  12  fasteners may be provided with mating undercut latching portions (not illustrated) so that they may be securely locked together.  
         [0017]    The key element in this fastener system of the present invention is the hollow module  16  defining a housing in which is contained a central compartment  18  defined on two sides by a pair of opposed elongated deformable walls  14 . The walls  14  preferably are substantially symmetrical when in non-deformed condition. Hollow expansion spaces  20  and  22  are formed in the housing  16  one positioned adjacent to and extend in the illustrated arrangement beyond both ends of the chamber  18 . These spaces preferably extend beyond the ends of the compartment  18 , but that is not essential. However it will be apparent that the length of the elongated wall  14  that can be deformed is dependent on the available space into which it may be deformed thus the length L S  and width W S  of the spaces  20  and  22  are important to the system. Generally the length Ls will be at least 80% of the length L C  (measured perpendicular to the walls  14 ) of the compartment  18  (i.e. the lengths of its adjacent wall  14 ) and preferably L S  is greater than 100% of the length L C  of the compartment  18 .  
         [0018]    The axial ends of the spaces  20  and  22  and the axial end walls of the compartment  18  are formed by the end walls  15  and  17  of the housing  16 . The lateral ends  19  and  21  of the housing  16  may be open (see FIG. 3) so that the compartment  18  and spaces  20  and  22  are open ended. In this case an expanding mechanism such as the bladder  23  (or other means such as expanding mechanical elements) may be positioned in the compartment  18  and inflated or deflated (as schematically illustrated by the two headed arrow  25 ) to press against the opposed walls  14  and deform them when inflated and permit them to move to relaxed (straight) position when the bladder  23  is deflated. Alternatively the ends  19  and  21  of the compartment  18  may be sealed and means be provided for pumping fluid into and out of he chamber or compartment  18  to deform the walls  14  as above described. Obviously the fluid used may be any suitable fluid such as air or hydraulic fluid.  
         [0019]    As above indicated the male members  10  are connected to and form an integral part of the housing  16  and are connected to the walls  14  (via the end wall  15 ) so that deformation of the walls  14  causes the free ends of the members  10  remote from the walls  14  to move toward each other and release their connection with the female element  12 .  
         [0020]    It will be noted that the manner in which the walls are deformed is important to having the ends  30  move as required to release the connection i.e. the walls  14  are moved apart more adjacent to the center of the walls (mid length L C ) than at the axial ends of the compartment  18  (measured in the length direction depicted by the length L C . The amount of movement of the free end  30  of the male member  10  is obviously dependent on the length L M  of the male member  10 .  
         [0021]    It will be apparent that the compartment  18  and the spaces  20  and  22  may extend substantially the full axial length of the body or housing  16 .  
         [0022]    It will be apparent that the outer walls  24  and  26  of the body  16  are not deformed when the walls  14  are deformed and thus are able to provide a stable surface for the attachment to one of the parts  28  that the fasteners are to interconnect. In the illustrated arrangement the socket  12  forms part of the second part  31  with which the part  28  is to be connected  
         [0023]    Connected to the body  16  and positioned between the male members  10  is a projection  40  the space  42  between the member or projection  40  may be designed to limit the deflection of the male members  10  when they are moved to unlocked or unlatched position shown in FIG. 2 (and as will be more filly described in connection with FIGS. 4 and 5).  
         [0024]    In operation the rest position for the preferred embodiment is illustrated (closed or latched position) is shown in FIG. 1 and the released or unlatched position shown in FIG. 2 where the walls  14  have been expanded into the spaces  20  and  22 . In the FIG. 1 position maximum spacing between the ends  30  is obtained to apply pressure against the side walls  32  of the cavity  12  forming the female connector  12 . It will be apparent that the side walls  32  and the adjacent sides of the male members  10  may be formed for example with latching undercuts to provide a more positive connection or formed in any suitable manner to provide a connection of the desired characteristics.  
         [0025]    In FIGS. 4, 5 and  6  like or similar parts have been designated with like numerals to those used in FIGS.  1  to  3  followed by the letter A.  
         [0026]    As shown the cavity  18 A in the body  26 A has a width W 1  measured perpendicular to the length L C  and the space  22 A has a similar length and a width W 3  and the wall  14 A between the cavity  18 A and the space  22 A has a thickness t 1 . It will be apparent that the wall thickness t 1  and length L C  (and the material from which the wall  14 A is made) are the main factors that determine the force required to deform the wall  14 A and unlatch the connector. The dimension W 3  defines the amount the wall  14 A may be freely deformed.  
         [0027]    The amount force (per unit length measured in the direction perpendicular to the paper in FIGS. 4, 5 and  6 ) that may be applied laterally by the male member  10 A in the direction of the arrow  50  is determined primarily by the thickness t 2  of the end wall  15 ; the thickness t 3  of the end wall of chamber  18 A measured between the top of cavity or chamber  18 A and the adjacent portion of the space  42 A; the width W 1  of the chamber  18 A; width W 2  of the unsupported portion of the end wall  15 A; the width W 4  of the top of the wall  14 A where it intersects the wall  15 A and the width W 5  of the root of the male member  10 A. These dimensions may be individually selected to determine the strength of the hinge structure of the top or end wall  15 A and thus the pressure applied in the direction  50 . The dimensions t 1  and L C  play a major roll in determining the amount of pressure that must be applied within the cavity  18 A to release the fastener. The dimension W 6  may be used to determine the amount of movement the male member  10 A may make toward unlatched position (this may also be determined by W 3 ) and more important may set the maximum deflection of the top of the cavity  18 A in the direction parallel to the length L C .  
         [0028]    The configuration of the intersection of the walls  14 A and  15 A may be manipulated to influence the strength of the hinge formed by the wall  15 A. For example as shown in FIG. 6 the lay  14 A may be undercut as indicated at  60  to in effect extend the effective width W 1  and/or the end of the wall  14 A may be flared outward (thickness of wall  14 A widened at the intersection with the wall  15 A) as indicated at  62  to shorten, in this illustration, the effective width of width W 2 .  
         [0029]    It will be apparent that the outer surfaces of the male members  10  may be of any suitable shape, for example they may be formed as segments of a circle that when in relaxed condition form an interference fit with a correspondingly shaped mating socket.  
         [0030]    Having described the invention modifications will be evident to those skilled in the art without departing from the spirit of the invention as defined in the appended claims.