Trailer Jack Add-On Gearbox

A removable gearbox has a plurality of gears in a housing and connected to a gear shaft and an input shaft of a trailer to allow the trailer to be raised and lowered with a battery operated drill.

BACKGROUND OF THE INVENTION

Most trailers are manufactured with one or more jacks to facilitate the raising and lowering of the front of the trailer when coupling or uncoupling with a tow vehicle (not shown). The jacks have an input shaft that is turned by a handle by the operator to raise or lower the front of the trailer. This turning of the handle by hand is difficult, requires significant effort and results in lost time and many injuries to the operator performing the work. Many trailers have to be delivered to or picked up from a spot requiring the tow vehicle to block the flow of traffic while uncoupling the trailer. The slow process of raising or lowering the front of the trailer by hand amplifies issues caused by the blocked traffic.

Thus, Applicant has invented a gearbox that can more easily lift and/or lower the front of a trailer by using a cordless drill.

SUMMARY OF THE INVENTION

According to one aspect, the present invention is directed to a removable gearbox to change a height of a trailer jack that includes a housing having a front and a back, a plurality of gears disposed within the housing, an input shaft receiver operatively connected to one of the plurality of gears, the input shaft receiver configured to receive at least a portion of an input shaft of the trailer jack therein and wherein the input shaft of the trailer is rotated to move a portion of the trailer jack up or down, at least one gear shaft extending through the front of the housing, the at least one gear shaft attached to the another of the plurality of gears and the another of the plurality of gears is operatively connected to the one of the plurality of gears; and two anti-rotation projections disposed on and extending away from the back of the housing to engage the trailer jack.

In some embodiments, the plurality of gears comprises a first gear, a second gear, a third gear, and a fourth gear and the one of the plurality of gears is the fourth gear and the another of the plurality of gears is the first gear.

In some embodiments, the input shaft of the trailer jack passes through at least one opening in the housing.

In some embodiments, there is a second gear shaft extending through the front of the housing and being connected to the third gear, the third gear operatively connected to the fourth gear.

In some embodiments, rotating the second gear shaft causes the second gear and the third gear to rotate, which in turn causes the first gear and third gear to rotate, the second gear rotates the first gear and the third gear rotates the fourth gear causing the input shaft of the trailer jack to rotate.

In some embodiments, the first gear and the third gear have a first number of teeth, the second gear has a second number of teeth, and the fourth gear has a third number of teeth, where the third number of teeth is greater than the second number of teeth, and the second number of teeth is greater than the first number of teeth.

In yet another aspect, there is a removable gearbox to change a height of a trailer jack that includes a housing having a front and back, a first gear, a second gear, a third gear and a fourth gear disposed within the housing, an input shaft receiver operatively connected to the fourth gear, the input shaft receiver configured to receive at least a portion of an input shaft of the trailer jack therein; and a first gear shaft extending through the front of the housing, the first gear shaft is attached to the first gear and rotationally engages the second gear that is operatively connected to the input shaft receiver.

In some embodiments, the second and third gear are disposed on the same gear shaft, the third gear rotationally engaging the fourth gear thereby rotating the input shaft.

In some embodiments, rotating the first gear shaft causes the first gear to rotate, which in turn causes the second gear and third gear to rotate, which in turn causes the fourth gear to rotate the input shaft of the trailer jack.

DETAILED DESCRIPTION OF THE INVENTION

Illustrated inFIG.1is one example of a trailer jack10that has one embodiment of a removable gearbox100to change a height of the trailer jack10. The trailer jack10generally has two portions10aand10bthat are movable relative to one another to raise and lower the front portion of the trailer, where the jack10is mounted. There is an input shaft12associated with the trailer jack10which, when turned, moves the front of the trailer up or down by moving the portions relative to one another

The input shaft12of the trailer jack10is removably connected to the gearbox100. By removable, Applicant means that the gearbox100is designed to be easily attached to and removed from the trailer jack10(or any conventional trailer jack) numbers of times. Thus, there are no parts that are destroyed during the removal of the gearbox100nor is there welding or other methods of securing parts together that make the gearbox100difficult to remove. It is designed to attached and unattached numerous times, e.g., hundreds if not thousands of times.

The removable gearbox100has a housing102that has a front104and a back106. The housing102may be made of two mirror-image pieces. It is also possible that one of the front104and the back106is thicker than the other or that they are independent of one another. The front104has a number of openings therein. A first opening108is to receive the input shaft12and an input shaft receiver110that surrounds the input shaft12as discussed below. The second opening112is to receive a first gear shaft114and the third opening116is to receive a second gear shaft118. As can be seen inFIGS.4and5, the second opening112and the third opening116do not extend through the back106, although it is possible. However, the input shaft receiver110preferably extends through an opening120in the back106. One of skill in the art would know that the second and third openings may also extend through the back106.

The front104and the back106are attached to one another by screws122but could be attached by other methods as well.

The removable gearbox100has a plurality of gears130disposed within the housing102. SeeFIGS.6and8. A first gear132is attached to the first gear shaft114so that when the first gear shaft114is rotated, so too does the first gear132. The first gear132is operationally connected to a second gear134. That is, when the first gear132is rotated, the second gear134also rotates. As is discernable from the figures, second gear134rotates counter to the first gear132. Thus, if the first gear132is rotated in a clockwise manner, the second gear134rotates in a counter-clockwise direction, and vice-versa. It should be noted that the first gear shaft114and the second gear shaft118have openings to receive projections that engage a cut-out on the gears130as is common in the art. The engagement of the gear shafts to the gears may be done in many ways and still fall within the scope of the present invention.

The second gear134and the third gear136are both disposed on the second gear shaft118. Thus, when the second gear shaft118rotates, so too do the second gear134and the third gear136. The third gear136is operationally connected to the fourth gear138. Thus, when the third gear136rotates, so too does the fourth gear138—in counter direction. The third gear136may rotate by turning either of the first gear shaft114or the second gear shaft118.

The fourth gear138is fixed relative to the input shaft receiver110. If the fourth gear is rotated, through either of the gear shafts114,118, then the input shaft receiver110rotates causing the trailer jack10to raise or lower the trailer to which it is attached. As illustrated inFIG.7, there may be a number of spacers140and bearings142to assist in the smooth operation of the gearbox100.

The gears130may have more or fewer teeth than illustrated in the figures. The first gear132and the third gear136have ten teeth132a,136a, while the second gear134has 20 teeth134a. Finally, the fourth gear138has 55 teeth138a. Again, this could be a matter of preference, the loads to be lifted, etc. SeeFIG.11. These gears130allow the user to one gear shaft when more torque is needed and the other gear shaft with more speed and less torque.

The input shaft12from the trailer jack10has a pin14that engages an opening144on the input shaft receiver110—thereby connecting the input shaft12with the input shaft receiver110. Turning of the fourth gear138causes input shaft receiver110to rotate, which turns the input shaft12raising or lowering the trailer jack10.

Illustrated inFIG.7is the gearbox with the input shaft receiver110extending out the back as an alternative in case the input shaft12is too short or the configuration allows for this alteration.

Extending outward from the back106and away from the gearbox100are two anti-rotation projections150. The anti-rotation projections150are separated to the left and right sides of the gearbox100so that the trailer jack10can fit between the anti-rotation projections150. While these anti-rotation projections150are attached to the gearbox100with screws (such as also with the screws122or even different ones), they could be attached in any other manner or be integral with the back106. They may also take other forms, such as flat surfaces. See alsoFIGS.15-17.

A second embodiment of a removable gearbox200according to the present invention is illustrated inFIGS.9-14. In this embodiment, the size, placement of the gears, and the gear shafts have be relocated.

The removable gearbox200has a housing202that has a front204and a back206. The housing202may be made of two mirror-image pieces. It is also possible that one of the front204and the back206is thicker than the other or that they are independent of one another. The front204has a number of openings therein. A first opening208is to receive the input shaft12and an input shaft receiver210that surrounds the input shaft12as discussed below. The second opening212is to receive a first gear shaft214and the third opening216is to receive a second gear shaft218. As can be seen inFIGS.10and11, the second opening212and the third opening216do not extend through the back206, although it is possible. However, the input shaft receiver210preferably extends through an opening220in the back206. One of skill in the art would know that the second and third openings may also extend through the back206.

The front204and the back206are attached to one another by screws222but could be attached by other methods as well.

The removable gearbox220has a plurality of gears230disposed within the housing202. SeeFIGS.12-14. A first gear232is attached to the first gear shaft214so that when the first gear shaft214is rotated, so too does the first gear232. The first gear232is operationally connected to a second gear234. That is, when the first gear232is rotated, the second gear134also rotates. As is discernable from the figures, second gear234rotates counter to the first gear232. Thus, if the first gear232is rotated in a clockwise manner, the second gear234rotates in a counter-clockwise direction, and vice-versa. It should be noted that the first gear shaft214and the second gear shaft218have openings to receive projections that engage a cut-out on the gears230as is common in the art. The engagement of the gear shafts to the gears may be done in many ways and still fall within the scope of the present invention.

The second gear234and the third gear236are both disposed on the second gear shaft218. The third gear236is behind the second gear234inFIG.12. SeeFIGS.12and14. Thus, when the second gear shaft218rotates, so too do the second gear234and the third gear236. The third gear236is operationally connected to the fourth gear238. Thus, when the third gear236rotates, so too does the fourth gear238—in a counter direction. The third gear236may rotate by turning either of the first gear shaft214or the second gear shaft218.

The fourth gear238is fixed relative to the input shaft receiver210. If the fourth gear238is rotated, through either of the gear shafts214,218, then the input shaft receiver210rotates causing the trailer jack10to raise or lower the trailer to which it is attached, depending on which way the gear shafts are turned. As illustrated inFIG.13, there may be a number of spacers240and bearings242to assist in the smooth operation of the gearbox100.

The gears230may have more or fewer teeth than illustrated in the figures. The first gear232and the third gear136have 10 teeth232a,236a, while the second gear234has 30 teeth234a. Finally, the fourth gear238has 37 teeth238a. Again, this could be a matter of preference, the loads to be lifted, etc. SeeFIGS.11and14.

The input shaft12from the trailer jack10has a pin14that engages an opening244on the input shaft receiver210—thereby connecting the input shaft12with the input shaft receiver210. Turning of the fourth gear238causes input shaft receiver210to rotate, which turns the input shaft12raising or lowering the trailer jack10.

A bracket300to be used with the removable gearboxes (100/200) is illustrated inFIGS.15-17. The bracket300has a back member302with two extensions304extending outward from the back member302. The back member302has an opening306to align with the opening (120/220) and the input shaft receiver (110/210). The spacing between the extensions304again should be the same as the trailer jack10. The bracket300and the extensions304in particular prevent the gearbox from rotating about the input shaft receiver110/210during use. As illustrated, the bracket300can be a separate item or it could be an integral portion of the back106/206.

Another bracket350that can be used with the removable gearboxes (100/200) is illustrated inFIGS.18-21. This bracket350was designed primarily to be used with the large semi-tractor trailers as the input shaft is in a different place than for the smaller trailers. The bracket350has an upper portion352and a top surface354, in particular, that engages the trailer, and a lower portion356that slides down the back of the removable gearboxes (100/200). There are preferably three slots358and360a/360bthat cooperate with the screws and input shaft receiver. As illustrated inFIG.19, the bracket350is attached to the removable gearbox100. The screws122in the slots360a/360bengage a portion of the bracket350and hold them still relative to one another.FIG.20shows the bracket350and the removable gearbox100from the front side.

FIG.21shows the bracket350and the removable gearbox100attached to the input shaft of the trailer. The gearbox100is ready to be used with the trailer. If the removable gearbox100starts to rotate relative to the trailer, the top surface354engages the underside380of the trailer and prevents the removable gearbox100from rotating. The upper portion352may be either longer or shorter than illustrated. It is preferable that the upper portion352extend outward on both sides of the bracket350to prevent rotation of the removable gearbox100when it is either lowering or raising the trailer.