Patent Publication Number: US-2021190261-A1

Title: Camera and rifle shooting tripod with tension-controlled swivil base and bi-directional leg angle locking system

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. § 119(e)(3) as a non-provisional perfection of prior filed a U.S. application No. 62/950,666, filed Thursday, Dec. 19, 2019, and incorporates the same herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the field of rifle shooting and photography equipment and more particularly relates to a new type tripod featuring a bowl-top and leveling base system assembly with a bi-directional leg angle locking system. 
     BACKGROUND OF THE INVENTION 
     There are three basic camera and shooting type tripods. The first is the traditional “center tube” style tripod which has three legs attached to a main hub and a center tube that penetrates thru the center of the hub and upon which may be attached various types of aiming devices or heads such as ball heads, pan heads, or video heads which are used to articulate an attached object such as a camera, gun, flash unit, light, projector, level, laser, etc. The center tube or the legs are used to adjust elevation while leveling is achieved by adjusting the length of the legs. The second type is a “flat-top” tripod which also has three legs and a main hub, but instead of a center tube it has a flat surface at the top of the hub upon where which may be attached a series of articulating heads or other devices. Elevation and leveling for this type of tripod is achieved only by adjusting the lengths of the legs. Finally, a “Bowl-Top” tripod is like a flat-top tripod except that a concave hemisphere surface or “bowl” of a given radius is fabricated into the top of the main hub. A matching hemispherical disk having an equal convex hemispherical radiused surface is installed into this bowl and can behave as an adjustable sphere, allowing the inserted disk to rotate to any prescribed angle within the available range of motion of the two mating hemispherical parts. Selected heads, such as those described above, may then be attached to this disk. The bowl-top tripod has primarily been used in videography to allow a videographer to quickly level a tripod head relative the horizon when deployed on uneven ground without having to manually adjust the length of the legs. This allows an attached head to be oriented such that the pan rotation axis of the head is precisely set to a vertical azimuth, so that while panning left to right, the camera will stay parallel to the horizon—a critical requirement for producing professional video imagery and panoramic scenes. The bowl disk is generally a member of a complete apparatus commonly referred to as a “leveling base.” A traditional leveling base consists of the aforementioned mating concave bowl disk, a second concave clamp disk, and a third, handle, member. The clamp disk rides on the bottom side of the main hub, pushing against a parallel offset surface that is opposite the tripod bowl surface. The handle has a bolt which passes through an opening formed the clamp disk and in the hub bowl that then connects to a threaded hole in top bowl disk. 
     In use, once the bowl disk is adjusted, or “leveled” to the desired position, the handle is then twisted to clamp both disks against the mating surfaces of the main hub to prevent the leveling base assembly from any further movement. Once locked, all further articulation of an attached object is achieved by virtue of the functionality, if any, of the attached apparatus. Thus, the industry naming convention of it being a “leveling base”; which is that its sole function of use; is to simply “level” or position the bowl disk to a prescribed fixed orientation. 
     Furthermore, traditional tripod systems allow tripod legs to lock in the outward direction but are free to collapse in the inward direction. The free-collapsing concept is practical for quick and easy retrieval and ease of mobility. However, tripods are also now being used where both horizontal and vertical loads are being applied, as opposed to just vertical loads, so that the free collapsing feature of the legs sacrifices stability and performance. Shooting guns from tripods is extremely common practice and the tripod must react to large lateral loads under these conditions. Tripods that do not react to these loads are not ideal for use. Far too many tripods have fallen over because of the common free-collapsing leg angle design concept. Some tripods are designed with additional hardware features to prevent this from happening. These systems typically consist of a series of articulating spanners or braces attached to each leg that expand and lock into position and keep the legs spread apart and locked in place. These systems are typically positioned towards to bottom of the legs or towards their middles. 
     One feature of this invention is a departure from the traditional bowl top/leveling base tripod design in that it eliminates the need to attach an independent articulating head to achieve dynamic motion or articulation of the connected device. Where all other systems utilize a static leveling base that “locks” the bowl disk in place, this design allows the bowl disk to act as a dynamic system which can move freely and precisely by incorporating a “precision tension-controlled” handle with sufficient spring compliance to allow the bowl disk to continuously rotate in the tripod hub bowl in such a fashion as to simulate the smooth motion normally achieved by an attached photographic head device. The spring-loaded handle, combined with proper material selection, material coatings, and the use of the precisely matched top and bottom bowl disk surface, produces dynamic smooth motion that cannot be achieved by other designs. 
     The use of a highly precision tension-controlled handle system, as opposed to a typical “on/off” leveling base locking handle, also provides the ability to set a very precise tension setting on the bowl/disk assembly. Doing so allows the tension setting to be equal to the friction break/hold point such that a mounted gun or camera can be easily manipulated, without having to loosen or re-adjust the handle tension setting, and thus achieve both smooth dynamic motion as well as a locked holding position with the same tension setting. 
     The benefits of making the bowl disk function as a dynamic system as opposed to just acting as a leveling base, extends to no longer requiring the addition of a separate articulating device or head in order make movement changes. An added benefit of eliminating the need for a separate head or aiming system is that the entire structure can be much shorter, lighter, stronger, and stiffer. This is beneficial because now a gun, camera, or other mounted devise can attach directly to the bowl disk and not be connected to a separate head, thus eliminating the compliance and springiness that is inherent with bending moments created by offset payloads attached to a tall camera head or tripod center tube. This improved stability greatly enhances the use of the tripod system for stabilizing firearms, heavy long lens cameras, spotting scopes, etc. 
     The elimination of an added head also offers the benefit of weight reduction. For the mobile outdoor user, elimination of a separate articulating head is a tremendous benefit for keeping the size and total-carry weight of the tripod to a minimum. The center of gravity of the attached payload is also beneficially shifted, thus greatly reducing the tendency of heavy payloads to “flop over” when making movements of the payload, which is inherent in the use of certain head designs such as a “ball head”. 
     Certainly, the fact that a precision tension bowl disk system capable of dynamic motion does not preclude it from also behaving as a traditional on-off leveling base with the similar ability to attach and hold any type camera head or other device directly to the bowl disk and achieve the same capabilities. 
     This invention also utilizes a bi-directional tripod leg angle lock system that is a complete departure from the concepts used in the prior art. No tripod designs exist where the bi-directional leg angle locking function is achieved at the hub-leg hinge point in the fashion used in this invention. Outward motion leg angle lock is traditionally accomplished at the leg hinge location, but an inward lock is not. This invention achieves both an automatic closing with the usual outward lock function but also offers an optional inward locking functionality at each angle lock position, all achieved at the tripod leg hinge joint location. The benefit of having bi-directional leg angle locking function achieved at this location is that it is much easier to use and deploy, generally less expensive to manufacture and with far fewer parts, much smaller by design, lighter to carry, and it provides other enhanced performance features not available in the existing spanner type leg lock designs. One such feature is the inherent strength enhancement added to the leg hinge point hardware. The “jam nut” used to lock leg angle also forces the mating components of the leg hinge hardware to their limit of travel built into the hinge joint manufacturing clearances typically used in tripod design. These clearances, by virtue of the jam nut design, are pressed to the clearance limits thus closing all the clearance gaps and create a metal-to-metal contact of all affected components, thus creating yet an even more robust joint connection not possible with other tripod designs. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing disadvantages inherent in the known leveling base bowl-top type tripod systems, leg angle locking systems, and leg hinge joints gaps, the advantages of an improved precision tension controlled dynamic bowl type tripod with a bi-directional leg angle locking system may meet the following objectives: that it be easy to construct and implement; that it provides greater stability to a supported object, even under lateral loads; that it provides fine adjustment control to the supported object; that be able to adjust within a large arc range for maximal leveling capability; that is inherently more stable due to a lower center of gravity; that it has less compliance when reacting offset loads due to it being sorter in height; that the reduction of required elements will be smaller and lighter to carry; that the legs be lockable in both inward and outward directions; that engaging the leg angle lock system also stiffens the leg hinge joint mechanism; that said locking mechanism be simple and intuitive to use. As such, to accomplish these objectives, a new and improved tripod system may comprise a precision tension adjustable bowl support, proper material selection with dynamic sliding surfaces, and a bi-directional locking tooth interface between the legs and tripod hub. 
     The more important features of the invention have thus been outlined in order that the more detailed description that follows may be better understood and in order that the present contribution to the art may better be appreciated. Additional features of the invention will be described hereinafter and will form the subject matter of the claims that follow. 
     Many objects of this invention will appear from the following description and appended claims, reference being made to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views. 
     Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for description and should not be regarded as limiting. 
     As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of one embodiment of a tripod. 
         FIG. 2  is a top plan view of the tripod of  FIG. 1 . 
         FIG. 3  is a sectional view of the tripod of  FIG. 2 , taken along line III-Ill. 
         FIG. 4  is a partially exploded view of the tripod of  FIG. 3 , focusing on the bowl-top control system. 
         FIG. 5  is a perspective view of a fingered support cup for use in a second embodiment of the tripod of  FIG. 1 . 
         FIG. 6  is a side elevation of the fingered support cup of  FIG. 5 . 
         FIG. 7  is a sectional view of another embodiment of a tripod using the support cup of  FIG. 5 , in the same view as  FIG. 3 . 
         FIG. 8  is a partially exploded view of the tripod of  FIG. 7 . 
         FIG. 9  is a partially exploded view of the leg locking system of the tripod shown in  FIG. 3 . 
         FIG. 10  is the tripod of  FIG. 3 , with the leg locking system fully disengaged. 
         FIG. 11  is the tripod of  FIG. 3 , with the leg locking system partially disengaged. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference now to the drawings, a preferred embodiment of the tripod is herein described. It should be noted that the articles “a”, “an”, and “the”, as used in this specification, include plural referents unless the content clearly dictates otherwise. 
     With reference to  FIGS. 1-4 , the tripod  100  features three legs  110  attached to a central hub  120  at arm  124 . A disk  130  resides in the central hub  120 . Precision handle  150  penetrates thru clamp disk  140  and thru springs  142  and attaches to mounting bolt  132  and interfaces with bowl disk  130  to tighten bowl disk  130  and clamp disk  140  against the central hub  120 , locking the bowl disk  130  in place. 
     As shown more specifically in  FIGS. 3 and 4 , bowl disk  130  more particularly resides within a bowl  126  fashioned in the hub body  128  and features a central mounting bolt  132  for a supported object or any adapters for such objects. Clamp disc  140  features a bowl top which interfaces with the hemispherical bottom surface of the central hub&#39;s bowl  126 . Bowl  126  features an incomplete bottom surface through which handle  150  may attach to bowl disk  130  with its bolt  152  through clamp disk  140 . For simplicity, bolt  152  may fasten into a threaded receiving end of central mounting bolt  132 . Locking nuts  154 ,  144  may be provided to help secure the bolt  152  in place. A highly compressive spring or other compliant member  142  is also provided between the handle  150  and clamp disk  140  to provide tension and separation distance between the clamp disk  140  and handle  150  when the handle is loosened or tightened. The compressive spring  142  may take any form, including but not limited to the stack of spring washers in cooperation with flat washers depicted in the figures. To adjust the bowl disk  130 , the handle  150  is loosened, increasing the spacing between clamp disk  140  and handle  150  thus decreasing the spring tension of clamp disk  140  and bowl disk  130  on to the hub  120 . Once adjusted, the handle  150  may be set to a prescribed tension setting or completely tightened to fully locked position. The presence of the compressive spring  142  allows for the clamp disk  140  and bowl disk  130  to have a minimum separation from the hub  120 , so that the static friction between them may be easily set to a precise break-away point if intended such that very small external input will allow bowl disk to move freely as commanded yet still hold an attached payload in a static position. The use of a fine pitch on bolt  152  also allows for controlled release of the handle  150  and the associated locking force between clamp disk  140  and hub  120 . The fine pitch thread also produces increased holding force on bowl disk  130 . Material selection and surface treatment of clamp disk  140  and hub  120  is essential to achieve smooth dynamic motion. A non-metallic material with a very low coefficient of friction such as nylon or DELRIN for clamp disk  140  proved to be helpful for precise, smooth, dynamic motion. 
     One alternate embodiment features an integrated clamp disk and compressive spring  146 , shown in  FIGS. 5 and 6 . The alternate clamp disk  146  features a bowl top with a multitude of fingers  148  forming its bowl. The alternate compressive spring  146  is made of a resilient material, such as metal or polymer, and may be manufactured of nylon or DELRIN. This resilience allows the fingers  148  sufficient flexibility to serve as the compliant member and provide compressive force on the bowl  126  when the handle  150  is tightened or loosened, as described in the previous embodiment. As shown in  FIGS. 7 and 8 , the single clamp disk  146  replaces both the original clamp disk  140  and compressive spring  142  in the system. 
     As seen in  FIGS. 3 and 9 , each leg  110  features a leg body  118  attached to a head  111 , possibly by a threaded interface. Adjustment tooth  112  is spring biased into a closed position. Each leg  110  is pivotably mounted  122  at its head  111  upon the central hub  120  at an arm  124  extending from the hub body  128 . The adjustment tooth  112  selectively interfaces with a plurality of teeth on the arm  124  and are preferred to be angled in a manner to allow ratcheting between the teeth. Depressing the adjustment tooth  112  against the bias spring  116  releases the tooth from its engagement and allows adjustment of the legs. However, jam nuts  114  are positioned underneath the adjustment teeth  112  and are threadingly engaged with the head  111 . When tightened, as shown in  FIG. 3 , the jam nuts  114  prevent actuation of the adjustment teeth  112  and hold the legs  110  in position rigidly against both vertical and horizontal forces. The jam nuts  114  may be loosened which will allow an adjustment tooth  112  to be depressed and free the legs for motion ( FIG. 10 ) or may be held by spring pressure against the arm  124  and allow only inward motion due to a ratcheting relationship between the teeth ( FIG. 11 ). 
     Although the present invention has been described with reference to preferred embodiments, numerous modifications and variations can be made and still the result will come within the scope of the invention. No limitation with respect to the specific embodiments disclosed herein is intended or should be inferred.