Method and apparatus for raising and lowering a trailer

A combination is disclosed having a trailer, telescoping support members, and a drive. The drive has a motor and a drive shaft, and the drive shaft has a first end portion affixed to a first cross member and a second end portion affixed to a second cross member. The first cross member is operably connected to means for moving the support members between raised and lowered positions. To install the drive on a trailer with a cross member, a segment of the cross member is removed and both ends of the drive shaft are affixed to portions of the remaining cross member. A kit having a drive and a template may be provided for retrofitting trailers. The template is a sheet that may be positioned on a cross member to determine locations for cuts and holes.

BACKGROUND OF THE INVENTION

The present invention relates generally to powered jacking devices and more particularly to powered landing gear for trailers.

Raising and lowering supports, such as landing gear or supports for trailers, can be a time-consuming and tiring physical task. It is known in the art to provide powered landing gear to eliminate the need for manually rotating a jacking device. The devices provide some advantages and benefits over relying simply on manual labor to provide the force needed to power jacking devices that raise and lower trailer landing gear. Still, prior attempts have met with very limited success because of a number of drawbacks. For example, prior art devices are typically complex, expensive, and difficult to install. Prior art devices have often been unreliable and are typically difficult to service, repair, or replace when problems arise. Prior art devices have often been connected to and relied upon the manual drive gearboxes of trailers, which can be undesirable for a number of reasons. For example, intermeshing a powered drive with a manual drive gearbox can make installation undesirably complex and time consuming. Further, intermeshing the powered drive with the manual drive gearbox can also impair the functionality of the manual jacking device and interfere with manual operation of the jacking device if that becomes necessary or desirable. Further still, the gearing used in different manual jacking devices can vary widely from device to device, so relying upon the gearing of different manual drive gear boxes can lead to an undesirable loss of predictability of performance. The complicated nature of the prior art devices and their methods of attachment have often made it undesirable for anyone other than a skilled technician to attempt retrofitting existing trailers with the devices.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a simple, reliable, inexpensive, powered jacking device that is easy to install and use.

It is a further object of the present invention to provide a device, kit, and method of installation of the above type that makes it easy to retrofit existing trailers.

It is a still further object of the present invention to provide a trailer that incorporates the simple, reliable, inexpensive jacking device of the present invention.

It is a still further object of the present invention to provide a device, kit, and method of installation of the above type that does not interfere with the operation of manual jacking devices.

It is a still further object of the present invention to provide a device, kit, and method of installation of the above type that does not rely upon the gearing of manual jacking devices to supply power to raise or lower supports or landing gear.

It is a still further object of the present invention to provide a kit that is inexpensive and easy to use.

It is a still further object of the present invention to provide a device, kit, and method of installation of the above type that may use a trailer's and vehicle's existing wiring system.

It is a still further object of the present invention to provide a device, kit, and method of installation of the above type that does not require a separate wiring and electrical systems.

It is a still further object of the present invention to provide a device, kit, and method of installation of the above type that is relatively small and light.

Toward the fulfillment of these and other objects and advantages, a combination is disclosed having a trailer, telescoping support members, and a drive. The drive has a motor and a drive shaft, and the drive shaft has a first end portion affixed to a first cross member and a second end portion affixed to a second cross member. The first cross member is operably connected to means for moving the support members between raised and lowered positions. To install the drive on a trailer with a cross member, a segment of the cross member is removed and both ends of the drive shaft are affixed to portions of the remaining cross member sections. A kit having a drive and a template may be provided for retrofitting trailers. The template is a sheet that may be positioned on a cross member to determine locations for cuts and holes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIG. 1, the reference numeral10refers in general to a drive of the present invention. The drive10has a motor12, drive shafts14and16, one or more gears18, and a  housing20.

The motor12is preferably a reversible electric motor and is more preferably a 6 horsepower, 12 volt DC, reversible electric motor. It is preferably capable of delivering 400 in.-lbs. output torque at 16 amps and 20 rpm, 600 in.-lbs. output torque at 25 amps and 17 rpm, and 800 in.-lbs. output torque at 32 amps and 15 rpm. The leads22and other electrical wiring are preferably a minimum of 14 gauge wiring and are more preferably 10 gauge. It is of course understood that any number of different sizes and types of motors may be used depending upon the desired characteristics.

Drive shaft14is operably connected to and extends from the motor12. A gear18is affixed to or formed into an end portion of drive shaft14. Similarly, a gear24is affixed to or formed into an intermediate portion of drive shaft16. Drive shafts14and16are aligned substantially parallel. One or more gears18operably connect drive shaft14to drive shaft16so that drive shaft16rotates at a much lower rpm rate than drive shaft14. The gears18are selected to provide a gear ratio from drive shaft14to drive shaft16that is preferably substantially within a range of from approximately 150:1 to approximately 60:1, that is more preferably substantially within a range of from approximately 125:1 to approximately 85:1, and that is most preferably approximately 105:1.

Drive shaft16preferably has a diameter of approximately 0.75 inches and has a length of approximately 5.4 inches. The drive shaft16has two output ends or end portions26and28. Holes30and32pass through end portions26and28of the drive shaft16. Holes30and32are aligned so that an axis of each hole is preferably perpendicular to and intersects an axis of drive shaft16. Each hole30or32preferably has a diameter of approximately 0.375 inches, and the axis of the hole is preferably approximately 0.4 inches from its respective end. The holes30and32are separated by a distance that is preferably substantially within a range of from approximately 3 inches to approximately 6 inches, that is more preferably substantially within a range of from approximately 4 inches to approximately 5 inches, and that is most preferably approximately 4.8 inches. Bushings34are provided and fit closely but rotatably over the output ends26and28. Holes36are provided in each bushing34, sized and disposed to line up with holes30and32in output ends26and28. Each bushing34has a length that is approximately 1.38 inches. The wall thickness of the bushing34is selected based upon the desired application as will be described in more detail below.

Housing20protects the drive10components and provides means for affixing the drive10to a trailer. The motor12, drive shaft14, and gears18are disposed within the housing20. At least a portion of drive shaft16, including gear24, is disposed within housing20, and portions of drive shaft16, including the end portions26and28and holes30and32, are disposed outside the housing20. Approximately 1.58 inches of the drive shaft16extends outside of the housing20on both sides of the housing. Threaded mounting holes38are disposed on the housing20, with axes of the mounting holes38disposed substantially parallel to axes of the drive shafts14and16. It is of course understood that the housing20made be made of any number of different pieces that may be fastened or affixed to one another in any number of different ways. An additional, protective outer housing (not shown) may be used to provide additional protection to the drive10and to provide additional shielding of the moving parts associated therewith. Any number of different shapes, sizes, and configurations may be used for the additional housing. The additional outer housing will typically have two openings to allow the cross member56to pass through.

FIG. 2depicts the drive10of the present invention affixed to a common configuration for a trailer support or landing gear40. The trailer42is not shown in this figure for clarity of presentation. In a typical landing gear40, one or more pairs of upper and lower support members44and46are provided. The upper support member44is affixed to the trailer42. The lower support member46is telescopically received within the upper support member44. Means48, such as a ball screw device or other suitable gear drive mechanism, are provided for raising or lowering the lower support member46between raised and lowered positions relative to the upper support member44. One or more rigid struts50may be provided, in any number of different configurations for rigidly affixing the upper support members44to the trailer42and each other for stability. A wide variety of different types and configurations of struts50may be used. In a typical, manually driven, landing gear40, a manual drive shaft52is provided and is coupled to a gear reducer box54that operably connects the manual drive shaft52to a cross member56. The cross member56is operably connected to the gear drive mechanism48for each pair of upper and lower support members44and46so that rotation of the cross member56moves the lower support members46between raised and lowered positions. The cross member56is preferably a pipe, is more preferably a pipe having an outside diameter that is substantially within a range of from approximately 1 inch to approximately 1.5 inches, and is most preferably a pipe having an outside diameter that is approximately 1.25 inches. The use of smaller drive shaft output ends26and28in combination with bushings34allows the drive10to be used in connection with a wide variety of cross members of different sizes and cross sectional configurations.

A rigid member58, such as an angle iron, is affixed to a strut50, to the trailer42, or some other suitable object that is stationary relative to the trailer42. The drive10is rigidly affixed to the angle iron58, such as by passing bolts through holes in the angle iron58and tightening them into the threaded mounting holes38. The rigid member58rigidly affixes the housing20so that it is substantially stationary relative to the trailer42and cross member56. The output ends26and28of the drive shaft16and associated bushings34are disposed inside respective sections56A and56B of the cross member56. Holes60are provided in the cross member56, the cross member holes60being aligned with holes36in the bushings34and holes30and32in the output ends26and28of the drive shaft16. Rigid members62, such as bolts, pass through and are secured within the holes60,36,30, and32in the cross member sections56A and56B, the bushings34, and the output ends26and28of the drive shaft16. The output ends26and28of the drive shaft16may be affixed to the cross member sections56A and56B at any number of locations along the length of the cross member56, so the drive10may be positioned in any number of locations. The use of the drive shaft16with two output ends26and28and the use of a plurality of threaded mounting holes38allows great flexibility in the positioning of the drive10relative to the trailer42and cross member56. For example, the motor12may be positioned above, below, in front of, or behind the cross member56. Similarly the motor12may be positioned to left or right of the gears18.

As seen inFIG. 3, the leads22of the drive10are connected to a wiring harness64. The wiring harness will typically include wiring of the desired gauge, an insulated cover, and suitable connectors. As mentioned above, the wiring is preferably a minimum of 14 gauge and is more preferably 10 gauge. The wiring harness64is spliced into the existing electrical wiring66of a trailer42so that it may be powered by the 12 volt power supply68of the tractor or towing vehicle70when the electrical wiring66of the trailer42is connected to the electrical system of the tractor70. A switch72, such as a toggle switch is included in and interconnects the wiring in the wiring harness64. The switch72may be positioned in any number of locations as desired. The switch72will typically be positioned near the landing gear40at a side of the trailer42. It is of course understood that the switch72may be positioned in any number of desired locations, including but not limited to various locations about the trailer42and about or in the tractor. Although a manual, toggle switch72is preferred, it is of course understood that any number of different controls may be used, including but not limited to electronic controls and wired or wireless controls. Although not required, to insure that the electrical wiring66of the trailer42is properly grounded, it is preferred to use a grounding device74. The grounding device74may be something as simple as a short segment of conductive wiring76with a clamp or clip78affixed to one end. An end of the wiring is affixed to a metal portion of the trailer42. After the trailer42is connected to the tractor or towing vehicle70, the clip78is temporarily affixed to a metal portion of the tractor or towing vehicle70.

To install a drive10of the present invention, such as in a retrofitting situation, a template80is preferably used (FIG. 4). The template80is a rectangular, pliant, sheet material with an adhesive82backing. First and second indicators84and86on the sheet identify first and second locations88and90for drilling holes60, and third and fourth indicators92and94on the sheet identify third and fourth locations96and98for making cuts. The first and second locations88and90are separated by a first distance that is preferably substantially within a range of from approximately 3 inches to approximately 6 inches, that is more preferably substantially within a range of from approximately 4 inches to 5 inches, and that is most preferably approximately 4.8 inches. The third and fourth locations96and98are separated by a second distance that is preferably substantially within a range of from approximately 1 inch to approximately 5 inches, that is more preferably substantially within a range of from approximately 2 inches to 4 inches, and that is most preferably approximately 2.875 inches. The first and second indicators84and86are preferably holes passing through the sheet, with the center of each hole identifying the location for drilling a hole. The third and fourth indicators92and94on the sheet are preferably lines, such as dashed lines, identifying the locations for making the cuts. It is of course understood that each indicator may take any number of different forms or combinations of forms, including but not limited to lines, dots, dashes, circles, perforations, score lines, holes, indentions, contrasts in color, shading, texture, or the like.

To perform an installation, a user determines an approximate location along the length of the cross member56for positioning the drive10, taking into account factors such as spacing considerations and the proximity of struts50or other bracing surfaces for rigidly affixing the drive10. The user places the template80on the cross member56in the desired location. The user drills through the pipe56at the first location88, creating two holes60, with the holes60aligned in opposite walls of the pipe56at that location. Similarly, the user drills through the pipe56at the second location90, creating two holes60, with the holes60aligned in opposite walls of the pipe56at that location. The holes60are sized to allow a bolt62of the desired size to pass through the holes60. The user makes cuts at the third and fourth locations96and98to remove a segment100of the cross member56disposed between the third and fourth indicators92and94. The cut pipe segment100is removed, leaving first and second pipe sections56A and56B. The template80is then removed. Although it is preferred to drill the holes60first, the holes60and cuts may be made in any order desired. It is also understood that the template80may be removed at any time desired in the process. After the cut pipe segment100is removed, one output end26of the drive shaft16, and a bushing34, are placed inside the first pipe section56A and the other output end28of the drive shaft16, and a bushing34, are placed inside the second pipe section56B. The respective holes60,36,30and32in the respective pipe sections56A and56B , bushings34, and output ends26and28of the drive shaft16are aligned, and rigid members62, such as bolts are passed through and secured within the respective holes to affix an output end portion26of the drive shaft16to one pipe section56A and to affix the other output end portion28of the drive shaft16to the other pipe section56B. The wires in the wiring harness64are affixed to the leads22of the drive10and are spliced into the electrical wiring66of the trailer42, and the switch72is affixed to the trailer42in the desired location.

If the electrical wiring of a towing vehicle70does not use wiring of the desired gauge, in an alternate embodiment, provisions may be made to wire the motor12directly to the battery68of the towing vehicle70without the need to use the existing wiring of the towing vehicle70. In this embodiment, a separate wiring harness is connected directly to the battery68. Wires of the harness may be routed to a rear portion of the towing vehicle70, where a plug or other common connector is provided. If this configuration is used, the wiring harness64connected to the drive10is not spliced into the electrical wiring66of the trailer42. Instead, one end of a harness64is connected to the drive10and the other end is provided with a mating plug or common connector for connecting to the front wiring harness. A switch72is disposed in the rear harness64and is affixed to the trailer42.

The invention may take the form of a kit, the kit including a drive10and template80as described above. Additional components, such as one or more wiring harnesses64and one or more switches72may also be included in the kit. It is of course understood that any number of different components and different combinations of components may be included in the kit.

In operation, when the lower support members46are in a lowered position and are supporting the trailer42in a raised position, the towing vehicle70is back into place for coupling to the trailer42. The electrical wiring66of the trailer42is connected to the electrical system of the towing vehicle70so that the motor12is powered by a 12 volt DC power source68from the towing vehicle70. The user affixes the clip78to a metal surface of the towing vehicle70to alleviate potential grounding problems. The user holds or depresses the switch72in a first position for rotation of the drive shaft16in a desired direction, which in turn rotates the cross member sections56A and56B. The rotating cross member sections56A and56B are operably connected to the gear drive mechanisms48so that the rotation of the cross member sections56A and56B raises the lower support members46from the lowered position to the raised position, thereby lowering the trailer42for coupling with the towing vehicle70. The user may start and stop the raising of the lower support members46as desired to make adjustments during the coupling of the trailer42to the towing vehicle70. The user continues the operation, until the lower support members46are raised to the desired degree. When the drive10is acting to move the lower support members46from the lowered position to the raised position, the drive10will rotate the cross member sections56A and56B at a rate that is preferably greater than or equal to approximately 8 rpm, that is more preferably greater than or equal to approximately 18 rpm, and that is most preferably greater than or equal to approximately 24 rpm.

For uncoupling the trailer42from the vehicle70, the user holds or depresses the switch72in a second direction, opposite the first direction, so that the drive shaft16rotates the cross member sections56A and56B in a direction for moving the lower support members46from a raised position to a lowered position. Until the lower support members46, or the shoes or pads forming parts thereof, contact the ground, the drive10will rotate the cross member sections56A and56B at a rate that is preferably greater than or equal to approximately 8 rpm, that is more preferably greater than or equal to approximately 18 rpm, and that is most preferably greater than or equal to approximately 24 rpm. The user may start and stop the lowering of the lower support members46as desired to make adjustments during the un-coupling of the trailer42from the towing vehicle70. Once the lower'support members46contact the ground so that the landing gear40begins to bear a load and raise a front portion of the trailer42, the rate of rotation of the cross member sections56A and56B will typically be reduced. As the lower support members46raise the front portion of the trailer42, the drive10will rotate the cross member sections56A and56B at a rate that is preferably greater than or equal to approximately 8 rpm, that is more preferably greater than or equal to approximately 12 rpm, and that is most preferably greater than or equal to approximately 18 rpm. The user continues this operation until the front portion of the trailer42has been raised to the desired level. At some point, before the towing vehicle70is moved away from the trailer42, the clip78is detached from the towing vehicle70, and the electrical system of the towing vehicle70is disconnected from the electrical wiring66of the trailer42.

Other modifications, changes and substitutions are intended in the foregoing, and in some instances, some features of the invention will be employed without a corresponding use of other features. For example, although the system is described for use in connection with landing gear40for a trailer42, it is understood that the system may be used in any number of different applications, including but not limited to providing for powered opening and closing of chutes, valves, tops, canopies, and the like. Similarly, the system may be used in connection with mobile or immobile applications. Also, although it is preferred that the motor12be powered by a 12 volt DC power source68already present on the towing vehicle70, it is understood that any number of different kinds, sizes, and types of power sources may be used and that a power source may be provided as part of the system. Similarly, the motor12may be selected so that it may also be powered by an AC power source such as may be readily available at locations where trailers42are frequently coupled and uncoupled to and from towing vehicles70. Although the output ends26and28of the drive shaft16are preferably placed inside cross member sections56A and56B and secured in place using bolts62, it is understood that any number of different ways may be used to couple the output ends26and28of the drive shaft16to the cross member sections56A and56B. Further, although it is preferred to use a template80to enhance the speed and accuracy of the installation process, a template80need not be used. Further still, the template80need not take the form of a sheet, need not be pliant, and need not have adhesive82on any or all of a surface. Further still, although many applications will involve landing gear40having two sets of upper and lower support members44and46, it is understood that in some applications other numbers of sets may be used, including one set or more. Of course, quantitative information is included by way of example and is not intended as a limitation as to the scope of the invention. Accordingly, it is appropriate that the invention be construed broadly and in a manner consistent with the scope of the invention disclosed.