Abstract:
A locking device that prevents a rooftop support device from being separated into upper and lower parts is disclosed. The locking device stops the lower base from being fully unscrewed from the upper platform. The device automatically releases to allow the lower base to be screwed back onto the upper platform.

Description:
FIELD OF THE INVENTION 
     The present invention is generally directed toward a device for preventing the upper platform of a rooftop support from disengaging from its base. 
     BACKGROUND OF THE INVENTION 
     A rooftop support, such as that disclosed in U.S. Patent Publication 2011/0192941, can be constructed of two parts, an upper platform and a lower base, which are threadably connected. 
     The height of the rooftop support is increased by rotating the lower base about its central axis. However, if the base is rotated beyond the point at which it is securely attached to the upper platform, the upper platform and load which it supports can become unstable. A heavy load could potentially topple and injure the operator of the rooftop support. 
     SUMMARY OF THE INVENTION 
     A locking device for a rooftop support is disclosed. The locking device prevents the upper platform of the rooftop support from separating from the lower platform. 
     The locking device automatically engages when the rooftop support reaches the desired maximum height. The locking device automatically disengages by simply turning the lower base back to decrease the height of the rooftop support. The locking device can also easily be disengaged to allow the upper platform to completely separate from the lower platform, if required. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages of the invention will become apparent by reference to the detailed description of preferred embodiments when considered in conjunction with the drawings: 
         FIG. 1  depicts a perspective view of the rooftop support, including the locking device. 
         FIG. 2  depicts a top plan view of the rooftop support. 
         FIG. 3  depicts a cross section view of the rooftop support as viewed along line  3 - 3  of  FIG. 2  and also showing a detail view of inset DETAIL A. 
         FIG. 4  depicts a top plan view of the lower base of the rooftop support including a detail view of inset DETAIL B. 
         FIG. 5  depicts a detail view of the locking device as the lower base is unscrewed from the upper platform. 
         FIG. 6  depicts a detail view of the locking device as the lower base is screwed in toward the upper platform. 
         FIG. 7  depicts a detail view of the locking device in a locked state. 
         FIG. 8  depicts a detail view of the locking device in an unlocked state with the release button depressed. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is presented to enable any person skilled in the art to make and use the invention. For purposes of explanation, specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required to practice the invention. Descriptions of specific applications are provided only as representative examples. Various modifications to the preferred embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the scope of the invention. The present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein. 
     Referring to the drawings,  FIG. 1  illustrates a rooftop support which includes the locking device  3 . The locking device  3  is mounted in a recessed section  4  of the upper rim of the lower base  2 . 
     As depicted in  FIG. 4 , locking device  3  is constructed of a single piece of a resilient material, such as plastic or metal. One end of locking device  3  has a lock body  11 , including a lock pin  6  which is configured to engage with slot  10  located in upper platform  1 . The opposite end  9  of locking device  3  rests in a groove  8 , which exists in one wall of recessed section  4 . 
     Locking device  3  is mounted in recessed section  4  such that lock body  11  can pivot about pivot point  5 . This mounting can be accomplished in several ways, including through the use of a bolt  13  that runs through pivot point  5 , or an extension of the locking device  3  that forms an axle  12  that is secured through a hole in lower base  2 , as can be seen in DETAIL A of  FIG. 3 . The pivot point  5  allows lock pin  6  to move both toward and away from the slot  10 . 
     Because the locking device  3  is made of a resilient material, it has both a relaxed state and a state of higher spring tension when its shape is deformed. Locking device  3  has a generally curved shape in its relaxed form, with the lock pin  6  engaged in slot  10 , as in  FIG. 5 . When the locking device  3  is not engaged, the locking device  3  is in a state of higher spring tension and takes a generally linear form. The built-up spring tension causes lock pin  6  to push against the threads of upper platform  1 . 
     When lower base  2  has not been unscrewed sufficiently from upper platform  1  to engage the locking device  3 , lock pin  6  is pressed against the grooves of the threads in upper platform  1 . As lower base  2  is unscrewed from upper platform  1 , lock pin  6  approaches the slot  10  which is located between the lower threads of upper platform  1 . As the lock pin  6  begins to pass over the slot  10 , the spring tension causes the lock pin  6  to enter the slot  10 , locking lower base  2  in place. Attempts to further unscrew lower base  2  beyond this point causes the lock body  11  and lock pin  6  to dig further into slot  10 , as illustrated in  FIG. 5 , preventing lower base  2  from being unscrewed. 
     It should be appreciated from  FIG. 6 , that the shape of lock body  11  causes the locking device  3  to automatically disengage from slot  10  if the operator attempts to screw lower base  2  back to upper platform  1  in order to decrease the height of the rooftop support. The curved surface where lock pin  6  and lock body  11  meet, combined with the flexibility of the lock body  11  to pivot about the pivot point  5 , facilitates this release. 
     This ability to disengage the lock by screwing lower base  2  back into upper platform  1  is particularly beneficial to the operator who is likely holding the object to be supported in one hand, and the rooftop support in the other hand. With both hands full, the operator would experience significant difficulties if lower base  2  completely unscrewed from the upper platform  1 . The material being supported could potentially topple on top of the operator. The lock prevents the operator from unscrewing lower base  2  too far. Because disengaging the lock is a simple matter of screwing lower base  2  back toward upper platform  1 , the operator does not need two hands to disengage the lock. 
     Locking device  3  may also optionally include release button  7  located between pivot point  5  and groove  8  as shown in  FIG. 7 . Release button  7  allows the operator to disengage the lock to completely separate lower base  2  from upper platform  1 . This feature is useful in situations where either lower base  2  or upper platform  1  need to be interchanged with another having different features or sizes. 
     As can be seen from  FIG. 8 , pressing release button  7  causes the locking device  3  to pivot about pivot point  5  such that lock body  11  and lock pin  6  move away from slot  10  in upper platform  1 , disengaging the lock. Preferably, release button  7  is shaped such that it extends far enough beyond the lip of lower base  2  to be easily pressed. However, release button  7  may just be a marked location on locking device  3  that indicates where to press to disengage lock pin  6  from slot  10  in upper platform  1 . 
     The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. The terms “a,” “an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. The term “one” or “single” may be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” may be used when a specific number of things is intended. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention. 
     The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention. It will be apparent to one of ordinary skill in the art that methods, devices, device elements, materials, procedures and techniques, other than those specifically described herein, can be applied to the practice of the invention as broadly disclosed herein without resort to undue experimentation. All art-known functional equivalents of methods, devices, device elements, materials, procedures and techniques described herein are intended to be encompassed by this invention. Whenever a range is disclosed, all subranges and individual values are intended to be encompassed. This invention is not to be limited by the embodiments disclosed, including any shown in the drawings or exemplified in the specification, which are given by way of example and not of limitation. 
     All references throughout this application, for example patent documents including issued or granted patents or equivalents, patent application publications, and non-patent literature documents or other source material, are hereby incorporated by reference herein in their entireties, as though individually incorporated by reference, to the extent each reference is at least partially not inconsistent with the disclosure in the present application (for example, a reference that is partially inconsistent is incorporated by reference except for the partially inconsistent portion of the reference).