Tripods having a panhead thereon have been used for video and photographic camera support devices. Typically these pods include three legs oriented at 120 degrees and are collapsible such that when not in use the tripod may be collapsed into a small package. Normally the legs are collapsible in a telescoping fashion such that the lower leg is received in a mid leg and the lower and mid legs are telescoped into an upper leg which is mounted to a structure on which a panhead is mounted and on which in turn a camera is mounted.
Tripods are typically used to support a camera at a low or high distance off the ground which is related to the length of the telescoping legs. Two different problems are involved, one relating to supoort on no-even surfaces and the other related to what is sometimes referred to as low angle location of the camera, i.e., relatively close to the ground in which two of the three telescoping lengths of each of the legs are in a retracted position.
Generally the legs include a ground engaging foot or pad which may be a resilient pad or a spike or both. The pad is typically used on hard surfaces and the spike is used on surfaces into which the spike may at least partially imbed itself to fix the position of the tripod.
Several problems exist with the feet or foot of the prior art tripods, as follows. In one foot structure, a spike is oriented axially and fixed with respect to the associated leg. Mounted on the threaded spike is a ball element on which is mounted a pad element. The ball is threaded to mate with the threads of the spike and the pad grips the ball. In one form of operation the ball and pad are rotated towards the supporting leg such tht the spike protrudes beyond the end face of the pad to engage the surface, but at an angle which is essentially the angular orientation of the leg with respect to the surface beneath the leg. Typically in the fully radially extending orientation of the legs this is at an angel of between 20 and 30 degrees and usually about 27 to 28 degrees. The pad, however, includes and angled top surface and an equally angled bottom surface such that the inner portion of the pad which is oriented towards the center of the tripod is of a vertical dimension greater than the outer portion of the pad which is oriented outwardly of the center of the tripod. The result of this foot-pad geometry is that in certain orientations of the tripod on uneven ground, it is necessary to rotate the pad so that the inner and outer portions of each of the pads is inside and outside with respect to the center of the tripod in order for the entire bottom surface of the pad to be in contact with the supporting surface. If this manual positioning of each of the pads is not performed, then each of the pads engage the opposing support surface only along a relatively small portion of the bottom surface of the pad, i.e., the entire bottom surface of the pad is not in contact with the supporting surface. The result is that the tripod is not stable.
In another form of prior device, a ball element is mounted in the leg such that the center axis of the ball is axially aligned with the leg. The ball element in the leg supports a second ball element which is pivotable and on which is mounted a foot. No spike is present in this structure. The difficulty with this structure is that the ability of the foot and the pad mounted on the foot to rotated inwardly is limited and is much less than the outward rotation of the foot and associated pad. The result is that if it is needed for the foot and pad to rotate inwardly an amount greater than the outward rotation in order for the foot and pad to engage the supporting surface, it cannot be achieved. The other disadvantages are the absence of a spike and the inability to provide a stable structure at low angles of tripod use.
Yet another prior structure is that in which a ball element is mounted on the leg such that a pad mounted on the ball may pivot but cannot rotate with respect to the ball. In this structure, there is no spike.
Still another prior device includes a spike oriented at an angle with respect to the axis of the leg and which includes a pad. In this structure, the pad cannot be oriented angularly with respect to the spike and can only be threaded axially with respect to the spike to expose the latter.
It is apparent from the above that a need exists for an improved leg and pad structure for a tripod in which both a spike and pad are provided such that either the spike or pad may be used on even or uneven ground and either of which are operative to provide stabilizing support.
USPTO Backgrounds
USPTO Backgrounds