Swivel jack assembly
View Patent ↗The assembly incorporates two plates. There are annular protrusions on one plate and a matching annular groove on the other. A central bolt and washer holds the plates in engagement while permitting rotation of one plate relative to the other. The cooperating annular grooves and protrusions transfer loads between plates. Ninety degrees of rotation causes the jack assembly to rotate from the vertical stowed position to the horizontal towed position.
1. A swivel jack assembly for dispersing a load, the swivel jack assembly comprising:
a mounting bracket affixed to an elongated tubular housing of a jack;
a first plate secured to the mounting bracket, the first plate having a first inner portion and a first outer portion in the same vertical plane, and having a first aperture in the center of the first inner portion and a shallow groove forming a narrow circular ring centered around the first aperture, separating the first inner portion and the first outer portion, wherein the shallow groove is no deeper than the thickness of the first plate;
a second plate secured to a trailer tongue, the second plate having a second inner portion and a second outer portion in the same vertical plane, and having a second aperture in the center of the second inner portion and a plurality of protrusions forming a discontinuous narrow circular ring centered around the second aperture, separating the second inner portion and the second outer portion, wherein the height of the protrusions are adapted to matingly engage the shallow groove of the first plate while the first inner portion of the first plate is in planar contact with the second inner portion of the second plate and the first outer portion of the first plate is in planar contact with the second outer portion of the second plate;
a bolt passing horizontally through the first aperture in the first plate and the second aperture in the second plate, securing the first plate to the second plate, and adapted so that when the shallow groove of the first plate accepts the plurality of protrusions of the second plate and a load is applied to the swivel jack, the shallow groove bears a load at an upper arc of contact between the shallow groove and the plurality of protrusions above the bolt, and the shallow groove bearing a load at a lower arc of contact between the shallow groove and the plurality of protrusions below the bolt; and
a releasable latch for securing the jack in either an upright position or a towed position, the releasable latch comprising a pin securing the first plate to the second plate,
wherein the load is distributed between the upper arc of contact and the lower arc of contact.
2. The swivel jack assembly of claim 1 , further comprising a tube, the tubular housing telescopically receiving the tube for raising and lowering the trailer tongue.
3. The swivel jack assembly of claim 2 , further comprising a wheel on the lower end of the tubular housing for easily moving a trailer attached to the jack assembly.
4. The swivel jack assembly of claim 1 , wherein the jack is released and can be rotated into either an upright position or a towed position when releasing the releasable latch.
5. The swivel jack assembly of claim 1 , wherein the first plate rotates around the bolt with respect to the second plate so the jack can be in an engaged upright position for supporting the trailer tongue or a disengaged towed position for traveling.
6. The swivel jack assembly of claim 1 , further comprising a tube inside the elongated tubular housing which is raised and lowered by turning a handle located on the jack.