Powered maneuverable and retractable trailer jack device

FIELD OF THE INVENTION

0001The present invention is in the general field of mechanical equipment, and more particularly weight bearing and transport equipment.

BACKGROUND OF THE INVENTION

0002Trailers of the type wherein the trailer tongue is supported by the towing vehicle require a jack stand to support the tongue and trailer frame in a horizontal position when not attached to a vehicle. This is performed by retractable jack stands, also referred to as “trailerjacks”, which are attached to the tongue, proximate to the trailer hitch. Trailer jacks on small single axle trailers have a foot plate or a single caster wheel mounted at the lower distal end of the jack. Larger weight capacity trailer jacks typically have a single foot plate which serves as the static support for the trailer tongue when the trailer is parked and unhitched. The smaller trailer jacks with casters are functional only to move the trailer without a load on it, or for very limited movement with a load to facilitate hooking up to a hitch. With the trailer loaded, the total weight is too great for manual movement upon the trailer main wheels and the jack caster.

0003Some attempts have been made to power trailer jack caster wheels to enable movement of a trailer when loaded. This is advantageous for maneuvering for hook-up with a hitch or maneuvering for parking. It is also advantageous to combine the functions of the jack stand with the mechanical powering of the caster or other translation devices or mechanisms.

0004Many jack stands are constructed with an external sleeve or housing, such as a steel tube, which is statically mounted to the trailer tongue. The external sleeve houses a screw jack assembly which is coupled to the stand which extends from the housing by operation of the jack. The foot plate or caster is attached to the lower distal end of the of the jack. In another trailer jack design, an external sleeve or housing carries an external gear rack which is mounted to the trailer tongue and engaged with a worm gear operable to raise and lower the jack stand relative to the trailer tongue. This design leaves the interior of the sleeve available for an additional shaft which can be used as a drive and steering shaft for a caster wheel mounted at the lower distal end of the sleeve.

0005Some of the problems with adding these mechanics to the standard trailer jack include the necessity of more complex housings and mountings. Also, the desirability of a larger wheel and tire in place of a single piece caster wheel requires a larger mounting fork, which then interferes with the retraction of the jack as required for the trailer in the traveling configuration. Satisfactory and economic engineering solutions to these challenges have not been provided.

SUMMARY OF THE INVENTION

0006The present invention provides a powered maneuverable and retractable trailer jack device for use with trailers of the type having a tongue which extends from or as part of the trailer frame for connection to a tow vehicle. The device includes ajack and a wheel-mounted tire which is powered for rotation to move a trailer by an integral drive mechanism. The jack may be internal or external to a shaft or sleeve which is attached to a trailer tongue, with a gear mechanism mounted to the shaft or sleeve. A wheel drive mechanism is generally internal to a sleeve and includes a chain-driven sprocket assembly to perform powered rotation of the wheel. The device may alternatively be pivotally mounted to a trailer tongue to retract to a stowed position. These and other aspects and alternative features are described with reference to the accompanying Figures.

DESCRIPTION OF THE DRAWINGS

0007<figref idref="DRAWINGS">FIG. 1</figref> is a perspective view of a first embodiment of a powered maneuverable and retractable trailer jack of the invention, shown in combination with the tongue portion of a trailer frame and a trailer hitch;

0008<figref idref="DRAWINGS">FIG. 2</figref> is a perspective view of another embodiment of a powered maneuverable and retractable trailer jack of the invention, shown in a retracted position and in combination with the tongue portion of a trailer frame and a trailer hitch;

0009<figref idref="DRAWINGS">FIGS. 3A and 3B</figref> are different perspective views of the first embodiment of the powered maneuverable and retractable trailer jack of the invention as depicted in <figref idref="DRAWINGS">FIG. 1</figref>, attached to the tongue portion of a trailer frame, in a retracted position (<figref idref="DRAWINGS">FIG. 3A</figref>) and in an extended position (<figref idref="DRAWINGS">FIG. 3B</figref>);

0010<figref idref="DRAWINGS">FIGS. 4A and 4B</figref> are different perspective views of the embodiment of the powered maneuverable and retractable trailer jack as depicted in <figref idref="DRAWINGS">FIG. 2</figref>, attached to the tongue portion of a trailer frame, in a retracted position (<figref idref="DRAWINGS">FIG. 4A</figref>) and in an extended position (<figref idref="DRAWINGS">FIG. 4B</figref>);

0011<figref idref="DRAWINGS">FIGS. 5A and 5B</figref> are elevation views of the embodiment of a powered maneuverable and retractable trailer jack of the invention as depicted in <figref idref="DRAWINGS">FIG. 1</figref>, shown in combination with a tongue portion of a trailer tongue of a trailer as shown in cross-section, in an extended position (<figref idref="DRAWINGS">FIG. 5A</figref>) and in a retracted position (<figref idref="DRAWINGS">FIG. 5B</figref>);

0012<figref idref="DRAWINGS">FIG. 6</figref> is an exploded perspective assembly view of the powered maneuverable and retractable trailer jack of the invention as depicted in <figref idref="DRAWINGS">FIG. 1</figref>, shown in combination with a tongue portion of a trailer tongue of a trailer;

0013<figref idref="DRAWINGS">FIG. 7A</figref> is a perspective exploded assembly view of the embodiment of a powered maneuverable and retractable trailer jack of the invention as depicted in <figref idref="DRAWINGS">FIG. 2</figref>, and <figref idref="DRAWINGS">FIG. 7B</figref> is a perspective view of the same embodiment of the powered maneuverable and retractable trailer jack of the invention in a retracted position.

0014<figref idref="DRAWINGS">FIG. 8</figref> is a perspective view of another embodiment of a powered maneuverable and retractable trailer jack in a retracted position;

0015<figref idref="DRAWINGS">FIG. 9</figref> is an assembly view of a gear drive and steering assembly of the powered maneuverable and retractable trailer jack;

0016<figref idref="DRAWINGS">FIGS. 10A, 10B</figref> and <b>10</b>C are perspective views of an alternate embodiment of a powered maneuverable and retractable trailer jack with an internal jack assembly;

0017<figref idref="DRAWINGS">FIGS. 11A, 11B</figref>, <b>11</b>C and <b>11</b>D are perspective views of an alternate embodiment of a powered maneuverable and retractable trailer jack, and

0018<figref idref="DRAWINGS">FIG. 12</figref> is a side view of an alternate embodiment of the powered maneuverable and retractable trailer jack.

DETAILED DESCRIPTION OF PREFERRED AND ALTERNATE EMBODIMENTS

0019Referring first to <figref idref="DRAWINGS">FIG. 1</figref>, a first embodiment of a powered maneuverable and retractable trailer jack of the invention is indicated generally at <b>10</b>, in combination with a trailer frame F and specifically attached to the tongue of the trailer frame F, which extends from the forward most end of the frame F to a hitch H, which is adapted to be coupled with a ball as attached to a ball mount M as shown within a receiver R of a trailer hitch assembly HA as are configured for attachment to the frame of a tow vehicle. The invention is not limited to use with these particular types of trailer frames, tongues and trailer hitches and in fact can be used in connection with any type of trailer to which the trailer jack <b>10</b> can be mounted.

0020The trailer jack <b>10</b> includes an external sleeve <b>12</b>. The sleeve <b>12</b> has an external gear rack <b>14</b> which is engaged with a drive gear mounted for rotation within a housing <b>16</b>. The housing <b>16</b> is also referred to the rack gear housing. The worm gear can be driven for rotation by a handle <b>18</b> to raise and lower the sleeve <b>12</b> vertically with respect to the trailer tongue T, as further shown in <figref idref="DRAWINGS">FIGS. 3A and 3B</figref> and in <figref idref="DRAWINGS">FIGS. 5A and 5B</figref>. The housing <b>16</b> is mounted to or made integral with a mount <b>20</b>, a lower portion of which is mounted to a top surface of the tongue T. One manner of attachment of the mount to the trailer tongue T can be by U-bolts which extend around the exterior of the trailer tongue as shown. A lower distal end <b>121</b> of the external sleeve <b>12</b> abuts the top surface of a wheel fork <b>22</b> within which is mounted a wheel <b>24</b> and tire <b>241</b>.

0021As further shown in the <figref idref="DRAWINGS">FIGS. 3A, 3B</figref>, <b>5</b>A and <b>5</b>B, the housing <b>16</b> and mount <b>20</b> are configured to position the described assembly, and in particular the wheel fork <b>22</b>, to a position lateral of the trailer tongue T such that the wheel fork <b>22</b> and attached wheel <b>24</b> can be fully retracted, to the position shown in <figref idref="DRAWINGS">FIG. 5B</figref>, wherein the wheel fork <b>22</b> and wheel <b>24</b> are laterally adjacent the trailer tongue T and the housing <b>16</b> and mount <b>20</b>. This maximizes the clearance of the wheel <b>241</b> from the ground with the trailer in the hitched-up traveling configuration.

0022The housing <b>16</b> and mount <b>20</b> can be configured in any manner which accomplishes this lateral offset of the assembly, i.e. trailer jack <b>10</b>, to maximize ground clearance in the fully retraced position. The mount <b>20</b> can alternatively be mounted directly to the housing <b>16</b> of a prefabricated retractable trailer jack, in the outboard position as shown to accomplish the lateral offset and enable full retraction.

0023As further shown in <figref idref="DRAWINGS">FIG. 6</figref>, an internal rod <b>26</b> fits within the external sleeve <b>12</b>. A lower distal end <b>261</b> of the internal rod <b>26</b> extends through the wheel fork <b>22</b> and to which is attached a drive gear <b>28</b>. The drive gear <b>28</b> is engaged with a cooperating beveled gear <b>29</b> mounted axially upon a drive shaft <b>30</b>, which is journalled to within the distal ends of the wheel fork <b>22</b>. Also mounted upon the drive shaft <b>30</b> is a drive sprocket <b>31</b>, on which is mounted a chain <b>32</b> which extends to engage with a wheel sprocket <b>33</b> mounted upon the axle <b>242</b> of wheel <b>24</b>. By this arrangement, axial rotation of the internal rod <b>26</b>, by manual or powered operation and for example by handle <b>262</b>, drives axial rotation of the wheel <b>24</b> and tire <b>241</b> to move the trailer T on its main wheels.

0024The large geared mechanical advantage from the drive gears <b>28</b>, <b>29</b> to the drive sprocket <b>31</b> and the relatively much larger wheel sprocket <b>33</b> facilitates the powered motion of the wheel <b>24</b> which bears the entire tongue weight of a loaded or unloaded trailer. The design further accommodates a relatively large wheel size and the preferred pneumatic tire <b>241</b> which further facilitates motion of a heavy load and over rough surfaces.

0025To enable turning of the wheel <b>24</b>, there is also within the external sleeve <b>12</b> an internal sleeve <b>40</b>, within which the internal rod <b>26</b> resides. The internal sleeve <b>40</b> is mounted at a lower distal end <b>41</b> to the top of the wheel fork <b>22</b>, and attached at an upper distal end <b>42</b> to a collar <b>43</b> with and a laterally extending handle <b>44</b> to turn the wheel fork and wheel <b>22</b> about the vertical axis of the internal sleeve <b>40</b>.

0026<figref idref="DRAWINGS">FIGS. 2, 4A</figref>, <b>4</b>B, <b>7</b>A and <b>7</b>B illustrate an alternate embodiment of the powered maneuverable and retractable trailer jack of the invention, indicated generally at <b>10</b>, which shares many of the components of the previously described embodiment but differs in the manner in which it is attached to the tongue trailer T. To enable the pivoting retraction as shown, the housing <b>16</b> is mounted to a pivotally mounted block <b>50</b> which rotates about a hinge pin <b>51</b> in a bracket <b>52</b> which is mounted to the trailer tongue T. In the flush position shown in <figref idref="DRAWINGS">FIG. 7A</figref>, the block <b>50</b> fits with an opposing bracket <b>53</b>, and a locking pin <b>54</b> extends through the block <b>50</b> and into the bracket <b>53</b> to lock the jack <b>10</b> in the pivotally retracted position as shown in <figref idref="DRAWINGS">FIG. 7B</figref>. The mounting of the housing <b>16</b> to the block <b>50</b> laterally offsets the jack <b>10</b> relative to the trailer tongue T so that the jack <b>10</b>, including wheel fork <b>22</b> and tire <b>241</b> is positioned adjacent to the tongue T in the fully retracted position for maximum ground clearance. As with the other embodiment, the housing may be formed integral with the blocks <b>50</b> and brackets <b>52</b>, <b>53</b>, or separately as a prefabricated component which is bolted or otherwise fastened or attached to block <b>50</b>. The lateral offset of the jack <b>10</b> to the trailer tongue T also enables full retraction of the external sleeve <b>12</b> prior to the pivoted retraction about the hinge pin <b>50</b>. The vertical adjustment of the gear rack assembly, and the steering function of the internal sleeve <b>40</b> is essentially the same as the other embodiment.

0027<figref idref="DRAWINGS">FIG. 8</figref> illustrates an alternate embodiment of a trailer jack <b>10</b> wherein the jack assembly includes a motor <b>263</b> connected for powered rotation of the internal rod <b>26</b> (as shown in <figref idref="DRAWINGS">FIG. 6</figref>) and the powered rotation of wheel <b>24</b> through the drive chain described with reference to <figref idref="DRAWINGS">FIG. 6</figref>.

0028<figref idref="DRAWINGS">FIG. 9</figref> illustrates an alternate arrangement for the powered rotation of internal rod <b>26</b> of the drive train described with reference to <figref idref="DRAWINGS">FIG. 6</figref>. A spur gear <b>60</b> is attached to the upper distal end of rod <b>26</b>. The spur gear <b>60</b> is in mesh with a beveled drive gear <b>62</b> attached to the end of handle <b>262</b> and within a housing <b>264</b> and under cover <b>265</b>. Rotation of gear <b>62</b> by handle <b>262</b> causes rotation of internal rod <b>26</b> to drive wheel <b>24</b> as described. The turning handle is mounted through a side wall of the housing <b>264</b>, and the housing <b>264</b> can be attached to the internal sleeve <b>40</b> described with reference to <figref idref="DRAWINGS">FIG. 6</figref> to enable the described turning operation by pivoting of the wheel fork <b>22</b>. To prevent unwanted rotation of the drive handle <b>262</b>, such as may occur when the trailer is on an inclined surface, a locking mechanism is incorporated into the turning handle <b>44</b>, such as in the form of a spring-biased pin <b>441</b> which fits within teeth of the spur gear <b>60</b>. The pin <b>441</b> extends from a shaft <b>442</b> mounted within a sleeve <b>443</b> which forms the handle <b>44</b> with a cover <b>444</b>. A release trigger <b>445</b> extends from the shaft <b>442</b> through sleeve <b>443</b> to disengage pin <b>441</b> from gear <b>60</b>, against the force of pin <b>446</b> and cap <b>447</b>.

0029<figref idref="DRAWINGS">FIGS. 10A-10C</figref> illustrates an alternate embodiment of a powered maneuverable and retractable trailer jack <b>10</b>, wherein the jack function is contained within the external sleeve <b>12</b>. An internal screw <b>140</b> is mounted for rotation within external sleeve <b>12</b> and internal sleeve <b>40</b>, and is threaded through a nut sleeve <b>142</b> which also fits within external sleeve <b>12</b>. The nut sleeve <b>142</b> is attached to spur gear <b>60</b> as shown, whereby rotation of gear <b>60</b> by handle <b>18</b> raises and lowers the screw <b>140</b> with respect to the nut sleeve <b>142</b> within the internal sleeve <b>40</b>. The external sleeve <b>12</b> can be mounted upon a bracket <b>70</b> which has a swivel pin <b>71</b> to allow the entire jack <b>10</b> to rotate relative to the trailer tongue T, as shown in <figref idref="DRAWINGS">FIG. 10B</figref>.

0030<figref idref="DRAWINGS">FIGS. 11A, 11B</figref>, <b>11</b>C and <b>11</b>D illustrate an alternate embodiment of a powered maneuverable and retractable trailer jack <b>10</b> in which a gear rack <b>80</b> is incorporated into the inner sleeve <b>40</b> of the jack, and threaded through a gear box <b>82</b> which is mounted on the external sleeve <b>12</b>. As shown in <figref idref="DRAWINGS">FIG. 11C</figref>, a worm <b>83</b> is mounted for rotation within gear box <b>82</b>, by meshed gears <b>84</b> and <b>85</b>, to rotate rack gear <b>86</b> upon the gear rack <b>80</b>. The outer sleeve <b>12</b> is mounted to a pivotable mount <b>70</b> as in <figref idref="DRAWINGS">FIGS. 10A-10C</figref> to enable pivoting retraction of the jack as shown in <figref idref="DRAWINGS">FIG. 11A</figref>.

0031<figref idref="DRAWINGS">FIG. 12</figref> illustrates an alternate embodiment of a powered and maneuverable trailer jack <b>10</b> mounted to a trailer tongue T by bracket <b>70</b> which as described as attached to the outer sleeve <b>12</b>. A torque arm <b>90</b> is provided to extend from a lower end of the sleeve <b>12</b>, as attached for example by a bracket <b>91</b>, to the trailer tongue T or to frame F, for example by bracket <b>92</b>. This provides greater stiffness to the trailer jack <b>10</b>, particularly in the vertical dimension and along the axis of sleeve <b>12</b>, which increases the static and dynamic load carrying capacity of the trailer jack <b>10</b>.

0032Although these particular embodiments and constructions are shown, other arrangements which perform the described functions are within the conceptual scope of the invention and claims. For example, other types of vertical jacks, including those with gears enclosed entirely within the external sleeve, and hydraulics, can be used in combination with the other operative components to accomplish the same or similar objectives. Also the described mountings can be by fasteners such as bolts or by welding or casting, or otherwise integrated or combined with the trailer tongue or hitch components.