Patent Publication Number: US-2023159005-A1

Title: Supporting trailers

Description:
FIELD OF THE DISCLOSURE 
     The disclosure relates to a system and method for supporting detached trailers, and more particularly, to electrically extending and retracting trailer landing gear legs. 
     BACKGROUND 
     Trailer landing gear include retractable legs that keep a towable trailer upright and stable when the towing vehicle is removed. They are most commonly used with heavy trailers, such as a semi-trailer. Typically, two landing legs are positioned near the forward end and underneath the trailer, and support the trailer so that the towing vehicle can be detached, or in the case of a semi-trailer, the truck can be driven out from under the trailer. To enable the landing gear to be raised and lowered, a system of reduction gears are used so that a single person can cause the landing gear to lift the heavy weight of the trailer by turning a hand crank many times. The current trailer landing gear system used on semi-trailers is therefore time consuming and tedious for truck drivers to use, and can produce repetitive motion injuries. 
     SUMMARY 
     The disclosure relates to a system for controlling extension and retraction of trailer landing gear of a trailer, with the landing gear including a shaft which is rotated to retract and extend the landing gear. The system comprises: an electric motor having an output shaft disposed 90 degrees with respect to a longitudinal axis of the motor; a mounting plate affixable to the trailer landing gear, the motor affixable to the mounting plate, the mounting plate sized and dimensioned to position the output shaft in axial alignment and adjacent to an end of the landing gear shaft, and to position the motor outboard of the trailer landing gear; and the motor connectable to the source of electricity to rotate and cause retraction or extension of the trailer landing gear. 
     The motor can include a rotor shaft connected to a 90 degree gear set, the output shaft connected to the gear set, the 90 degree gear set releasably attachable to the motor. The system can further include an electric switch electrically connected to the source of electricity and the motor to cause the motor to rotate in a first direction, a second direction, and to stop rotation, whereby the switch can be used to control extension and retraction of the landing gear. In an embodiment, the system can further include a relay connected to the switch, the motor, and the source of electricity, the switch connected in a circuit with the relay to activate the relay to cause the motor to be electrically energized. 
     The system can also include an adapter having a first end sized and dimensioned to securely couple to the output shaft, the adapter having a second end sized and dimensioned to securely couple to the landing gear shaft. The system can also have a reinforcing plate attachable to the trailer landing gear and the mounting plate. In this regard, the reinforcing plate can be provided with openings at predetermined locations corresponding to locations of existing openings in the trailer landing gear, whereby mounting bolts can be positioned through the reinforcing plate and the trailer landing gear. 
     The mounting plate can be provided with openings at predetermined locations corresponding to locations of existing openings in the trailer landing gear, whereby mounting bolts can be positioned through the mounting plate and the trailer landing gear. Additionally, one or more mounting bolts can each be positioned through the mounting plate and the trailer landing gear and the reinforcing plate. 
     In an embodiment, the trailer landing gear is of the type including a movable leg portion and fixed leg portion. The system can include a movable limit contact affixed to the movable leg portion, and at least one fixed limit contact affixed to the fixed leg portion. The movable limit contact and the at least one fixed limit contact are mutually cooperative to limit an extent of movement of the movable leg portion and the fixed leg portion when the movable limit contact and the fixed limit contact are at least one of mutually in contact and mutually in proximity. At least one of the movable contact and the at least one fixed contact can be an electrical switch. The electrical switch can be connected to an electrical circuit operative to interrupt a supply of electrical power to the motor. Further, at least one fixed limit contact can be positioned above the movable limit contact to control retraction of the landing gear, and at least one fixed limit contact can be positioned below the movable limit contact to control extension of the landing gear. 
     The shaft of the landing gear can be either an input shaft connectable to a handle and connected to reduction gears or a transverse shaft not connected to reduction gears, with the motor output shaft connectable to either the input shaft or the transverse shaft. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present disclosure, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: 
         FIG.  1    depicts a prior art semi trailer; 
         FIG.  2    depicts an underside of a prior art semi trailer together with prior art trailer landing gear; 
         FIG.  3    depicts a detail of prior art landing gear; 
         FIG.  4    is a perspective view of trailer landing gear provided with a landing gear extension and retraction system of the disclosure; 
         FIG.  5    is an alternative perspective view of the system of  FIG.  4   ; 
         FIG.  6    is a detailed alternative perspective view of a portion of the system of  FIG.  4   ; 
         FIG.  7    is a detailed alternative perspective view of a portion of the system of  FIG.  4   ; 
         FIG.  8    is a perspective view of a mounting bracket in accordance with the disclosure, dismounted from the system of  FIG.  4   ; 
         FIG.  9    is a detailed perspective view of a dismounted motor and gear system of the system of  FIG.  4   ; 
         FIG.  10    is a detailed perspective view of an adapter in accordance with the disclosure, dismounted from the system of  FIG.  4   ; 
         FIG.  11    is a detailed perspective view of an opposite side of the adapter of  FIG.  10   ; 
         FIG.  12    is a perspective view of a reinforcing plate of the disclosure, dismounted from the system of  FIG.  4   ; 
         FIG.  13    is a perspective view of a movable limit contact of the disclosure, dismounted from the system of  FIG.  4   , as best seen in  FIG.  15   ; 
         FIG.  14    is a side view of the system of  FIG.  4   ; 
         FIG.  15    is a front view of the system of  FIG.  4   ; and 
         FIG.  16    is a detailed alternative perspective view of the system of  FIG.  4   , showing prior art reduction gears positioned inboard of a landing gear mounting frame. 
     
    
    
     DETAILED DESCRIPTION 
     As required, detailed embodiments are disclosed herein; however, it is to be understood that the disclosed embodiments are merely examples and that the systems and methods described below can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present subject matter in virtually any appropriately detailed structure and function. Further, the terms and phrases used herein are not intended to be limiting, but rather, to provide an understandable description of the concepts. 
     The terms “a” or “an”, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms “including” and “having,” as used herein, are defined as comprising (i.e., open language). The term “coupled,” as used herein, is defined as “connected,” although not necessarily directly, and not necessarily mechanically. 
     The disclosure provides an automated trailer landing gear system  100  for replacing or augmenting the current landing gear crank system. The system can be powered by the electrical system of the truck as connected to the trailer, and can be controlled by a switch mounted to the trailer, or by a remote control. 
     Prior art landing gear systems  50  are shown in  FIGS.  1 - 3   . In  FIG.  1   , landing gear system  50  is positioned under a forward portion of the trailer  40 , leaving space forward for the frame, wheels, and fifth wheel of a semi-truck (not shown) to pass underneath.  FIG.  2    provides a detailed view. With reference to  FIGS.  3  and  16   , a reduction gear system  52  is positioned on an outer surface of a landing gear leg  54 . 
     Additionally, an input shaft  56  is connectable to a crank handle  58 . As input shaft  56  is rotated, reduction gears  60 , for example as can be seen in  FIG.  16   , cause rotation of a transverse shaft  62 . Input shaft  56  typically extends from one landing leg set to the other landing let set, so that both legs move up or down simultaneously. 
     Further in accordance with the prior art, bevel gears  64  or the like engage a gear  78  on transverse shaft  62  to thereby translate rotation of transverse shaft  62  ninety degrees to a vertical threaded shaft  66 . As threaded shaft  66  turns, threads (not shown) engage an internal plate (not shown) mounted to a lower leg segment  70 , which causes relative motion between lower leg segment  70  and an upper leg segment  72 , which causes telescoping of the leg  54 . A mounting frame  68  connects leg  54 , and other components cooperative with leg  54 , to the trailer  40 . Typically, handle  58  is pushed in or pulled out to alternately cause the engagement of faster or slower reduction gears. Reduction gears  60  can be positioned outboard of frame  68  or inboard of frame  68 . Typically, transverse shaft  62  extends beyond reduction gears  60  to a stub  74 . In some versions of landing gear, stub  74  includes a cross-bore so that hand crank  58  can be connected directly to transverse shaft  62 . 
     In accordance with the disclosure, system  100  can be implemented to cooperate with the various permutations of the prior described herein. An output shaft  104  of an electric motor  102  is connected to either stub  74  or input shaft  56  to cause actuation of the landing gear when motor  102  is energized and output shaft  104  rotates. As can be seen in the figures, motor  102  is provided with a 90 degree output gear set  106 , which has an output shaft having an axis that is oriented 90 degrees with respect to both a longitudinal axis and a rotor rotational axis of the motor. Gear set  106  enables an alignment of motor  102  along a longitudinal axis of the trailer when motor  102  is installed. In this manner, motor  102  does not project beyond a periphery of the trailer; does not interfere with manual operation of the landing gear via crank  58 ; and a larger motor can be accommodated. In an embodiment, motor  102  has an integrated 90 degree output shaft. 
     A mounting plate  110  is attachable to the trailer, for example to the trailer  40  frame or to mounting frame  68 , the latter as shown in the figures. Mounting plate  110  is positioned to cause alignment of output shaft  104  with input shaft  56  or stub  74  of transverse shaft  62 , as determined in accordance with a predetermined configuration plan. Mounting plate  110  can be connected to trailer  40  or mounting frame  68  by bolts, welding, press fit, or any other manner which provides sufficient strength and reliability. Likewise, motor  102  and attached gear set  106  are attached to mounting plate  110 , for example using mounting points  112  provided with gear set  106 . In the embodiment shown, mounting plate  110  extends at a right angle from mounting frame  68 , and motor  102  is attached to hang from an underside of mounting plate  110 , on an outboard side of the landing gear. More particularly, mounting plate  110 , as shown in the figures, can be dimensioned to position motor  102  on an outer side of mounting frame  68 , where it is easiest to mount and maintain motor  102  and associated components. This mounting location additionally avoids landing gear reinforcing bars and other structure which is typically located inboard of mounting frame  68  (see e.g. prior art  FIG.  2   ). 
     An adapter  120  can be used to couple motor  102  output shaft  104  to input shaft  56  or stub  74 . A keyway  122  can be provided within a first end  128  of the adapter to mate with a corresponding key  124  on the output shaft  104 , or a corresponding keyway on output shaft  104 , into which a locking key can be inserted. Alternatively, a mating spline, a flexible coupling, or any other means of coupling output shaft  104  with adapter  120  can be provided. 
     At a second end  130  of adapter  120 , a transverse bore  126  is provided, which can be mated with input shaft  56  in a like manner as handle  58 , for example with a pin or bolt, provided a mating transverse bore is also formed through the shaft to be mated. To enable use of adapter  120  on stub  74 , which may not have a transverse bore, a bore can be drilled through stub  74  to accommodate a mounting pin, or second end  130  can be sized to fit over stub  74 , and attached through an interference fit, threading, welding, or any other method. 
     By connecting directly to transverse shaft  62 , system  100  can be attached without disassembly or replacement of the existing gear system  52 . In addition, when system  100  is connected to transverse shaft  62 , the manual crank system remains intact and usable as before. 
     In an embodiment, as can be seen in  FIG.  12   , a reinforcing plate  136  is positioned against mounting frame  68  to provide additional strength for mounting frame  68 , and in particular to strengthen an attachment of mounting plate  110 . As motor  102  is mounted a distance from mounting frame  68 , and as mounting plate  110  extends at a right angle from mounting frame  68 , a substantial bending force could be exerted upon mounting frame  68 , particularly while motor  102  is operating. Reinforcing plate  136  is attached to lie against mounting frame  68  and to clamp mounting frame  68  between mounting plate  110  and reinforcing plate  136 , to thereby counteract this bending force. Reinforcing plate  136  can be attached to mounting frame by any known means, including bolts, as shown, or by welding, adhesive, or any other means. As can be seen in  FIG.  6   , reinforcing plate  136  is advantageously also connected to mounting plate  110 , for example by bolts  138 . In addition to various mounting bolt through holes  140 , a central aperture enables passage of transverse shaft  62  and associated bearing  80 . Openings  168  in reinforcing plate  136  as well as mounting plate  110  can be positioned to correspond with existing openings in mounting frame  68 , thereby avoiding a requirement of drilling holes for mounting bolts. 
     Motor  102  can be energized by electrical power that is already present throughout the trailer. A motor switch  144  controls operation of motor  102 , and has an off position, and two running positions: retract (up), and extend (down). Switch  144  can be attached to mounting frame  68 , the trailer body, or to any other location convenient for a user of system  100 . 
     Motor  102  can be configured to rotate in a first direction when a positive voltage is applied, and a second, opposite direct when reverse voltage is applied, which can be carried out by the two miming positions of switch  144 . An electrical circuit can be provided for reversing rotational direction, if required by the motor. Likewise, a reversing transmission can alternatively or additionally be provided as required or specified. Switch  144  can be connected to a relay by smaller wires, for safety and ease of mounting and positioning. 
     Switch  144  can alternatively or additionally have the form of a remote control (not shown) so that an operator can stand clear as the landing gear operates. Communication electronics for the remote control (not shown) would therefore be provided in the motor control circuit described herein. 
     Power can be provided by a battery or generator associated with the trailer, although it can be simpler to use power provided to the trailer by the towing vehicle. Trailer connectors used throughout the world typically include at least one pin/line which is electrically powered at all times, and which can provide the requisite electrical supply. Examples of such powered lines in heavy trucks in North America can be found in a typical 7-way SAE J560 specification connection between the tractor and the trailer. More particularly, this specification includes an ‘aux and ABS power’ line. In some configurations of this specification, there are alternatively ‘electric brakes’ and ‘aux power’ lines. Other configurations, including 5- and 6-way specifications, may include an ‘electric brakes’ line. All of the foregoing specifications, as well as a 4-way specification, include a ‘tail lights’ line. 
     Logically, an ‘aux power’ or other line designated for auxiliary systems would be an optimal choice, as it is not necessarily connected to safety-oriented lighting or braking systems. This is particularly important when retrofitting a trailer with a system  100  of the disclosure, as alteration of an electrical system after manufacture can introduce points of failure. A second choice would be a ‘tail lights’ line, and a last choice would be a line relating to braking, unless it is otherwise designated for auxiliary equipment. Manufacturer guidelines should be consulted, and would of course take precedence to any of the above. 
     Wires leading from the connector travel through races or other passages, usually along the underside of the trailer. An appropriate wire representing the desired line connection can be selected, and an additional wire can be spliced onto this line for supplying switch  144 , and ultimately motor  102 . Alternatively, a designated wire can be extended between switch  144  and a junction box associated with the trailer connector. 
     Where motor  102  requires a larger “startup” amount of power, a capacitor or other motor starter circuit can be provided. If motor  102  requires more power than can be provided in real time by the selected line, a battery  142  of sufficient size, and a charging circuit, can be connected to the selected line, and the battery can thereafter provide the startup power, supplemental power, or all of the power required by motor  102  during use. Between uses, the battery can “trickle charge” without taxing the electrical system of the towing vehicle. Alternatively, a solar recharging system can be used, or a recharging system associated with parts of the trailer which rotate during use, or any other regenerative system. The battery and charging circuit can be positioned in any convenient location. If the battery is a lithium or other highly efficient type battery, it can be small and easily positioned underneath the trailer or upon mounting frame  68 , or upper leg segment  72 , for example. It should be understood that switch  144 , motor  102 , wiring, and any battery system should be adapted for the voltage available, typically 12 or 24 volts, and the maximum wattage requirements. 
     Further in accordance with the disclosure, a sensor system  150  is provided for controlling an extent of retraction and extension of lower leg segments  70 . Limiting over-extension or over retraction is advantageous, particularly where motor  102  is sufficiently powerful to cause damage to components of leg  54  at the limits of travel. With reference to  FIGS.  14 - 15   , a shaft  152  is affixed to lower leg segment  70  at a shaft lower end  154 , and is optionally slidingly supported at a distance up from the lower end by a ring anchor  164  positioned upon upper leg segment  72 . A movable limit contact  158  is positioned upon shaft  152  near a shaft upper end  156 . As a result, as lower leg moves, a position of movable limit contact  158  changes with respect to upper leg segment  72 . Shaft  152  can be hollow, to enable wiring to extend from movable limit contact  158  to a transmitter or control circuit; alternatively any shape supporting member can be used. 
     A extend limit contact  160  is positioned upon upper leg segment  172  at a distance below movable limit contact  158 , the distance corresponding to an extent of extension of leg  54 . When leg  54  is fully extended, movable limit contact  156  interacts with extend limit contact  160 , which causes interruption in the electrical supply to motor  102 . Movable limit contact  158  can be positioned upon a threaded portion  166  of shaft  152 , or can otherwise be adjustably positioned upon shaft  152 , so that the limit of extension can be adjusted. In an embodiment, movable limit contact is threaded ( FIG.  13   ). 
     It should be understood that shaft  152  and movable limit contact can be affixed to upper leg  72 , and lower leg can include the one or more fixed limit contacts. 
     In one embodiment, one or both of movable limit contact  158  and extend limit contact  160  is an electrical switch, for example a momentary style of switch, and the interaction is caused by proximity or contact between the two limit contacts  156 ,  160 . Examples of switch styles include mechanical or magnetically activated. These switches can be wired to a wireless transmitter, for example located within case  162  or elsewhere, or can be wired directly back to a motor control circuit (not shown), or one or more of the switches can include a wireless transmitter. Where a wireless transmitter is used, it can communicate with the motor control circuit. Where the switches are wired, they can be electrically connected to a circuit which includes a relay operative to interrupt a supply of electricity to the motor. 
     In another embodiment, shaft  152  is raised or urged upwards by the contact of movable limit contact and extend limit contact  156 ,  160 , activating a switch or sensor associated with or within case  162  positioned at shaft lower end  154 . As examples, case  162  can include any or all of a strain gauge, mechanical switch, magnetic switch, proximity sensor, light sensor, or other sensor type. Any of the foregoing sensors or switches, whether mechanical or otherwise, can be protected within an enclosure or seal to keep out moisture or debris. 
     Setting a retract limit can be accomplished in the same manner as described for an extend limit, except that retract limit contact  160 A is positioned above movable limit contact  158 , but is otherwise activated as described with respect to the combination of limit contacts  158  and  160 . Alternatively, in one embodiment, case  162  is rigid, and interferes with upper leg  72  at a limit of retraction, and is thus sized with an appropriate height. 
     In an embodiment, the disclosure is carried out with only 6 parts, including motor  102 , 90 degree output gear set  106 , mounting plate  110 , reinforcing plate  136 , switch  144 , and adapter  120 . All of these components are positionable outboard of mounting frame  68 , greatly facilitating installation. Mounting and reinforcing plates  110 ,  136  can be provided for each model of landing gear commonly used, each including bolt hole openings  168  which correspond to existing bolt hole openings in mourning frame  68 , whereby no holes need to be drilled for installation. However, if it is necessary to drill holes, all parts are easily accessed from beside, and not under, the trailer. 
     All references cited herein are expressly incorporated by reference in their entirety. It will be appreciated by persons skilled in the art that the present disclosure is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. There are many different features to the present disclosure and it is contemplated that these features may be used together or separately. Thus, the disclosure should not be limited to any particular combination of features or to a particular application of the disclosure. Further, it should be understood that variations and modifications within the spirit and scope of the disclosure might occur to those skilled in the art to which the disclosure pertains. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present disclosure are to be included as further embodiments of the present disclosure.