Abstract:
An apparatus for aligning a trailer hitch and receiver includes an elongated channel or tube defining an angle, such that when the trailer is tilted back for hitching, the upper tube is substantially vertically aligned. A rubber tipped rod extends from the lower tube and contacts the vehicle when the vehicle draws near the trailer. As the rod is pushed into the lower tube, a connecting rod drives an actuator or indicating rod upwards. A calibration tube is slid over the upper tube, and is aligned along the upper tube to expose a brightly colored painted region on the indicating rod at the point where the receiver and hitch are aligned one above the other. Alternatively, the calibration tube moves a series of switches up or down, whereby the actuator is pushed by the rod to contact the switches successively to indicate the approach to and arrival at a hitching position, by the illumination of electric lights, and or by activation of an audible signal. The calibration rod may alternatively slide on the lower tube, wherein the contact rod creates or activates electrical connections within the calibration tube. The apparatus may further be incorporated into the trailer frame, before or after manufacturing. One or more of the apparatus may be placed near the rear of the trailer to aid lateral alignment, or to gauge the distance of the trailer to an object behind the trailer, either before or after hitching.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a light weight easily deployed indicator for aligning a vehicle and a trailer while the vehicle is backing up, including indication of both lateral and longitudinal alignment. 
     BACKGROUND OF THE INVENTION 
     The difficulties in backing a vehicle to engage a trailer hitch are well known. A miscalculation on the part of the driver can result in damage to the vehicle, typically by the trailer coupling body striking the rear of the vehicle, and may also result in damage to the trailer, its contents, or injury to people or objects nearby. 
     A challenge specifically arises in aligning the ball, pintle or other hitch (“hitch”) with the trailer coupling body (“coupler”) both laterally and longitudinally. Lateral alignment requires that the coupler is centered side to side with respect to the vehicle. Longitudinal alignment requires that the coupler is the correct distance from the rear of the vehicle. 
     One device to facilitate alignment is disclosed in U.S. Pat. No. 5,669,621 to Lockwood, wherein one post and flag is disposed proximate the hitch, and another post and flag is disposed proximate the coupler. Using this device, the driver maneuvers the vehicle to bring the flags in proximity. This device, however, requires that the driver properly gauges the lateral and longitudinal alignment between flags, including the rate at which the flags are converging. As a practical matter, this is difficult for many drivers. 
     U.S. Pat. No. 6,273,448 to Cross, and U.S. Patent Publications 2005/0218626 to Kwilinski, and 2006/0220345 to Schmidt, present alternative means to gauge longitudinal alignment. Specifically, in these references the trailer hitch strikes a panel or a part of the flag post, causing either a visible or audible alarm, or movement of the flag pole, to alert the driver when the hitch is near the coupler. These methods, however, still present a danger of the hitch missing the strike zone of the device, whereby the hitch and coupler pass each other, with attendant consequences as described above. Moreover, in all of these devices, there are no indications until the hitch and coupler are very close, and thus a vehicle backing at speed may simply overshoot the target, as may occur with the device of Lockwood. 
     U.S. Pat. No. 6,851,697 to Kinnard extends a metal tape in the direction of the vehicle, whereby when the hitch and coupler are a more significant distance apart, an indicator begins to reveal their relative proximity. Kinnard additionally activates if there is lateral misalignment, as there is no longer a necessity of hitting a strike zone near the coupler. 
     In Kinnard, however, heavy, rigid materials are required, as well as a stout mounting system and bracket body which are bolted to the jack post of a trailer. Trailers without a jack post cannot accommodate the device of Kinnard. Further, there is a requirement that the jackpost be positioned sufficiently close to the forward edge of the trailer, so that the device may contact the vehicle when extended. 
     Permanently mounted devices, such as disclosed in Kinnard, may not have a need to be buoyant, as they are not likely to fall into the water. However, a device which is quickly and easily removed without tools would greatly benefit from being buoyant, if dropped into water. Kinnard, however, is not adapted to be floatable without the addition of a substantial quantity of buoyant materials. 
     It would further be advantageous to have a device which offers a soft, dampened contact, as opposed to contact by a rigid metallic tape or the like. In Kinnard, the metal tape is described as usually contacting the license plate, which does not pose as much a problem with respect to scratching or denting as the painted bodywork of a vehicle. As a practical matter, however, contact with the bodywork of the vehicle can be expected, and the device must therefore not pose a potential hazard to the vehicle&#39;s finish. 
     Another advantage would be to have a device which, in addition to other attributes, greatly facilitates visual lateral and longitudinal alignment, is of low cost, that can easily moved from one trailer to another, is quickly and easily calibrated, is sufficiently light and buoyant to float, is easier to see, and presents a minimum of risk of damage to the vehicle or trailer in use. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, a device is provided which assists in maneuvering a tow vehicle towards a towed object, rendering both longitudinal and lateral alignment guidance, whereby the towed coupling is disposed in engaging proximity to the towing hitch. 
     In one embodiment, a hitch guide includes a main body comprising a lower channel or tube reversibly attached to a trailer draw bar or coupling area, generally longitudinally aligned with the trailer. Connection may be by any of a variety of means, including magnets, brackets, hook and loop fasteners, bolts, or straps. 
     Magnets are advantageous employed in that trailer construction materials commonly include magnetically active metal, and thus attachment requires only that the main body and attached magnets are placed in proximity to the desired attachment point. Magnets may be disposed along any side of the main body, so that attachment can be made on the side or bottom of the device. 
     An engagement rod is slideably retained within the main body, and extends towards the vehicle during deployment. The engagement rod is advantageously made of a lightweight material, such as fiberglass, but may be of any suitably rigid material. The end which contacts the vehicle is advantageously constructed of, or coated with, a material which is resilient and is not likely to scratch paint of a vehicle. A fiberglass rod with a rubber tip has been found to work well. 
     The main body is bent upwards at an angle. Because the trailer coupler is typically raised above the vehicle hitch prior to connection, the trailer frame to which the lower tube is attached is typically tilted backwards. As a result, the upwards bend of the lower tube is oriented substantially vertically during use of the device. 
     A calibration channel or tube is slideably disposed in connection with and extending upwards from the main body. Together, the calibration tube and the main body form a continuous channel or tube. An actuating or indicator rod is slideably retained within the calibration tube, extending upwardly therefrom. 
     A flexible connector is connected to both the engagement rod and indicator rod, disposed within the main body and calibration channel. Accordingly, as the engagement rod is pushed or pulled within the main body, a commensurate movement is imparted to the indicator rod, extending from the calibration tube. 
     Indicator means are provided at the distal end of the indicator rod. In one embodiment, holes are provided in the calibration body, through which a contrasting color on the indicator rod becomes visible when the rod is extended upwardly. In another embodiment, colored bands, or written indicia become visible when the rod is extended upwardly. Alternatively, both indicator means may be used simultaneously. 
     In use, the device is first calibrated as follows. With the trailer hitched to the vehicle, the device is placed on the trailer draw bar or other rigid structure at the leading end of the trailer. The engagement rod is slid within the main body, so that the indicator rod is in an elevated position. The calibration tube is slid up or down until the visible indicators correspond to a finished or stop position. The calibration tube will maintain its position through frictional engagement with the main body. Tape or other means may be used to further ensure that the calibration tube is not inadvertently moved. 
     After calibration, an unhitched trailer may be hitched as follows. While maintaining the calibration tube in the same position as determined during calibration, the engagement rod is slid to extend forwards, advantageously to a full extent. Accordingly, the indicator rod descends within the calibration tube and main body. 
     The vehicle is then backed up towards the trailer at a reasonable speed. Lateral alignment is accomplished by gauging the location of the device with respect to a centerline of the vehicle, assuming the hitch is oriented at the center of the vehicle. Various means of identifying the center of the vehicle may be employed as needed, as described in the prior art, and particularly as described in U.S. Pat. No. 6,851,697 to Kinnard, incorporated by reference herein. Those means include a sticker or other marker on the rear view mirror or rear window. A marker may similarly be placed on the tailgate or other part of the vehicle. Lateral alignment can then be gauged by noting the offset of the device with respect to the marker while observing the rear view mirror, or by turning and viewing the marker and device directly. 
     When the vehicle is sufficiently close to the trailer, the vehicle will contact the engagement rod, and will begin to push same into the main body. Concurrently, the indicator rod rises from the calibration tube. The driver observes the indicator rod, and when the markings indicate a stop position, the driver stops the vehicle, at which point the hitch and coupler will be laterally and longitudinally aligned. The trailer tongue is then lowered onto the receiver and coupled to complete the connection. 
     In an alternative embodiment in accordance with the invention, electrical or electronic means cooperative with lights signal the proximity of the vehicle. In this embodiment, the calibration tube slides within the lower portion of the main tube. The calibration tube houses a series of electrical contacts. The engagement rod slides within the calibration tube, extendable towards the vehicle in use. Disposed about the inner, or proximal end of the engagement rod, is at least one electrical contacting surface electrically contactable with the electrical contacts inside the calibration tube, whereby at least one circuit may be formed as the engagement rod slides within the calibration tube. 
     The electrical circuits correspond to signals operative to illuminate a series of indicator lights which are indicative of the vehicle proximity. In one embodiment, the lights, for example incandescent bulbs or LED&#39;s, are disposed about the uppermost portion of the main body. The electrical circuits may form a direct connection between a power source and the lights, or may signal an electronic processor to flash or otherwise control operation of the indicator lights. 
     Calibration of an electrical embodiment in accordance with the invention is accomplished by coupling the trailer, and maintaining the engagement rod in contact with the vehicle while sliding the calibration tube forwards or backwards until the indicator lights signal that the vehicle is in position. 
     In a further embodiment in accordance with the invention, a flag mounted to a flexible post indicates correct longitudinal alignment. The flag post is mounted to extend upwardly from an upper disposed calibration tube. A pin extends from the distal end of the post, operative to enter a retaining aperture in the calibration tube. To prepare for deployment, the flag post is bent over until the pin enters the retaining aperture. The bent post applies an angular force to the pin, whereby the pin is reversibly jammed in the retaining aperture. An ejecting ramp is disposed at the upper end of the flexible connector. When deployed, the flexible connector moves the ramp upwardly to drive the pin from the retaining aperture, whereby the flag is raised by the resilience of the flag post. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present invention, 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  illustrates a hitch guide in accordance with the present invention; 
         FIG. 2  illustrates the hitch guide of  FIG. 1 , in use; 
         FIG. 3   a  illustrates an upper portion of the hitch guide of  FIG. 1 ; 
         FIG. 3   b  illustrates an indicator rod of the hitch guide of  FIG. 1 ; 
         FIG. 4   a  illustrates an alternative embodiment of an indicator mechanism, in accordance with the invention, with a flag pole retained; 
         FIG. 4   b  illustrates the embodiment of  FIG. 4   a , with a flag pole released; 
         FIG. 5  illustrates an alternative embodiment for retaining the flag pole of  FIG. 4 ; 
         FIG. 6  illustrates an illuminated embodiment in accordance with the invention; and 
         FIG. 7  illustrates an alternative illuminated embodiment in accordance with the invention; 
         FIG. 8  illustrates an alternative location for mounting a hitch guide in accordance with the invention; 
         FIG. 9  illustrates yet another alternative location for mounting a hitch guide in accordance with the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the figures in which like reference numerals refer to like elements, an exemplary hitch guide  10  in accordance with the invention is illustrated in  FIG. 1 . With reference to  FIG. 2 , in accordance with the invention, guide  10  assists in maneuvering a tow vehicle  12  towards a towed object  14 , rendering both longitudinal  16  and lateral alignment guidance, whereby the towed coupling is disposed in engaging proximity to a towing hitch  18 . 
     A ball and receiver style hitch is illustrated in  FIG. 2 , however it should be understood that the invention may be used in combination with other known forms of hitches, where it is important to gauge the relative proximity of hitch portions while moving a towing member towards a towed member. 
     Referring again to  FIG. 1 , in one embodiment, a hitch guide  10  includes a main channel or main body  20  comprising a lower channel or tube  20   a  reversibly attached to a trailer draw bar  22  or coupling area, generally longitudinally aligned with trailer  14 . Connection may be by any of a variety of means, including magnets  24 , or brackets, hook and loop fasteners, bolts, or straps (not shown). The main body and other channels or tubes may be advantageously fabricated from PVC (polyvinyl chloride), wood, metal, plastic, or other suitably rigid and durable material. PVC is advantageously utilized due to its low cost, easy formability, and buoyancy. 
     Magnets  24  are advantageous employed in that trailer construction materials commonly include magnetically active metal, and thus attachment requires only that the main body and attached magnets are placed in proximity to the desired attachment point. Due to the light weight construction of a device in accordance with the invention, small, inexpensive magnets suffice for suitable connection strength. Magnets  24  may be disposed along any side of lower tube  20   a , so that attachment can be made on the side or bottom of the device. In  FIG. 1 , magnets  24  are illustrated on the bottom of lower tube  20   a , connected by adhesive or mechanical fasteners, such as pins  24   a.    
     A contact extension or engagement rod  26  is slideably retained within main body  20 , and extends towards the vehicle  12  during deployment. Engagement rod  26  is advantageously made of a lightweight material, such as fiberglass, but may be of any suitably rigid material. Tip  28 , which contacts vehicle  12 , is advantageously constructed of, or coated with, a material which is resilient and is not likely to scratch paint of a vehicle. A fiberglass rod with a rubber tip has been found to work well. 
     Main body  20  is bent upwards at an angle, and defines a first length or first end or lower tube substantially aligned to the longitudinal axis of the trailer when installed, and a second length or second end or upper tube extending upwards with respect to the first end. As can be seen in  FIG. 2 , because trailer coupler  30  is typically raised above vehicle hitch  18  prior to connection, trailer frame  22  to which main body  20  is attached is typically tilted backwards. As a result, the upwards bend of the upper tube is oriented substantially vertically during use of the device  10 . 
     In one embodiment, a calibration channel or tube  32  is slideably disposed in connection with and extending upwards from main body  20 . Together, calibration tube  32  and main body  20  form a continuous channel or tube. An actuator or indicator rod  34  is slideably retained within calibration tube  32 , extending upwardly therefrom. 
     A flexible connector  36  is connected to both engagement rod  26  and indicator rod  34 , connector  36  being disposed within main body  20  and calibration channel  32 . Accordingly, as engagement rod  26  is pushed or pulled within main body  20 , a commensurate movement is imparted to indicator rod  34 , extending upwards from calibration tube  32 . 
     Visible indicator means  38 , 40 , 42  are provided at the distal end of the indicator rod. In one embodiment, holes  42  are provided in calibration tube  32 , through which a contrasting color  44  ( FIG. 3   a , 3   b ) on indicator rod  34  becomes visible when rod  34  is extended upwardly. In another embodiment, colored bands (not shown) or written indicia  38  become visible when the rod is extended upwardly. Alternatively, both indicator means  38 , 44  may be used simultaneously, as shown. Indicator means  40  is visible at all times, and aids in visually locating the device, as well as in lateral alignment, described elsewhere herein. In addition, indicator means  40  may take the form of a buoyant device, to help ensure device  10  does not sink if dropped into water. 
     In use, device  10  is first calibrated as follows. With trailer  14  hitched to vehicle  12 , or at least hitch portions  18 , 30  longitudinally aligned, device  10  is placed on trailer draw bar  22 , or other rigid structure at the leading end of trailer  14 . Engagement rod  26  is slid within main body  20 , so that indicator rod  34  is in an elevated position. It may be necessary to move device  10  towards or away from vehicle  12  until indicator rod  34  is elevated, and tip  28  contacts vehicle  12 . Calibration tube  32  is slid up or down until visible indicators  38 , 44  correspond to a finished or stop position. Calibration tube  32  will maintain its position through frictional engagement with main body, for example through the use of one or more grommets or collars  46 . Tape or other means (not shown) may be used to further ensure that the calibration tube is not inadvertently moved. 
     After calibration, an unhitched trailer may be hitched as follows. While maintaining calibration tube  32  in the same position as determined during calibration, the engagement rod is slid to extend forwards, advantageously to a full extent. Accordingly, indicator rod  34  descends within calibration tube  32  and main body  20 , and a “stop” position is no longer indicated. 
     Vehicle  12  is then backed up towards trailer  14  at a reasonable speed, decreasing prior to or immediately following contacting tip  28 , as evidenced by movement of indicator rod  34 . While backing, before contact with tip  28 , lateral alignment is accomplished by gauging the location of the device with respect to a centerline of vehicle  12 , assuming hitch part  28  is oriented at the lateral center of vehicle  12 . Various means of identifying the center of vehicle  12  may be employed as needed, as described in the prior art, and particularly as described in U.S. Pat. No. 6,851,697 to Kinnard, incorporated by reference herein. Those means include a sticker or other marker (not shown) on the rear view mirror or rear window. A marker  48  may similarly be placed in a laterally central location on tailgate  50 , or other part of the vehicle. Lateral alignment can then be gauged by noting the offset of device  10  with respect to marker  48 , while observing the rear view mirror, or by turning and viewing marker  48  and device  10  directly. 
     When vehicle  12  is sufficiently close to trailer  14 , vehicle  12  will contact engagement rod  26 , and will begin to push same into main body  20 . Concurrently, indicator rod  34  rises from calibration tube  32 . The driver observes indicator rod  34 , and when markings  42 , 38  indicate a stop position, the driver stops vehicle  12 , at which point hitch  18  and coupler  30  will be laterally and longitudinally aligned. The coupler  30  is then lowered onto receiver  18  and connected to complete the connection.  FIG. 1  illustrates a “stop” condition and indication. 
     To assemble device  10 , flexible connector  36  is fastened to either engagement rod  26  or indicator rod  34 , and the assembly is slid within main body  20 , coupled to calibration tube  32 , as far as possible. Flexible connector  36  is then pulled taught, to expose a length just sufficient for attachment to the remaining unconnected part, either engagement rod  26  or indicator rod  34 , such that after engagement, a resilience of flexible connector  36  causes the connected end to be withdrawn within main body  20  or calibration tube  32 , and thus the connection is no longer disposed exterior to main body  20 . As shown in  FIG. 1 , flexible connector  36  is attached by being threaded into a hole in each of engagement rod  26  and indicator rod  34 . Alternatively, attachment could be by any known means, such as clips, hooks, clamps, threaded connection, adhesives or the like. 
     With reference to  FIGS. 4   a ,  4   b  and  5 , in a further embodiment in accordance with the invention, flag  60  is mounted to resilient flexible flag post  62 , to indicate correct longitudinal alignment. Post  62  is mounted to extend upwardly from an upper disposed calibration tube  32   a . Catch or pin  64  extends from post  62 , in this embodiment from the distal end of post  62 , operative to enter retaining aperture  66  in calibration tube  32   a . To prepare for deployment, post  62  is bent over until pin  64  enters retaining aperture  66 . Because post  62  enters retaining aperture  66  at an angle with respect to the bore of aperture  66 , an angular force is applied by pin  64  to aperture  66 , whereby pin  64  is reversibly jammed within aperture  66 . Ejecting actuator or ramp  68  is disposed at the upper end of flexible connector  36  (not shown in  FIG. 4   a , 4   b ), and is connected thereto in a secure manner, such as the manner shown with respect to indicator rod  34  shown in  FIG. 1 . When deployed, flexible connector  36  moves ramp  68  upwardly to drive pin  64  sufficiently out of aperture  66  to overcome the friction imposed by the angular displacement of pin  64 , whereby pin  64  is released from retaining aperture  66  through the resilient force applied by post  62 , whereupon flag  60  is further raised by the resilience of the post  62  to indicate longitudinal alignment, and a stop position. 
     An alternative release mechanism is shown in  FIG. 6 , wherein catch or pin  64  is replaced by lower mating clasp  70 , and ramp  68  is replaced by upper mating clasp  72  lower clasp  70  is connected to post  62 , and upper clasp  72  is disposed within calibration tube  32   a  (not shown in  FIG. 5 ). Lower clasp  70  enters aperture  66  (not shown in  FIG. 5 ), and is engaged with upper clasp  72 , by moving engagement rod  26  first inwards to admit passage of lower clasp  70 , and then outwards to engage lower clasp  70  with upper clasp  72 . As in the embodiment shown in  FIGS. 4   a , 4   b , when engagement rod  26  is pushed inwards by contact with vehicle  12 , upper clasp  72  is raised, releasing lower clasp  70 , wherein post  62  straightens through inherent resiliency, thus raising flag  60 . 
     In an alternative embodiment of a device  90  in accordance with the invention, illustrated in  FIG. 6 , electrical or electronic means cooperative with lights  92  signal the proximity of vehicle  12 . Lights  92  are advantageously LEDs or other bright, energy conserving light source, although incandescent or other light source may be effectively employed. In this embodiment, a calibration tube  82  slides within the lower portion  80   a  of main tube  80 . Calibration tube  82  is supported to slide within main body  80  by standoff  98 , which is connected to calibration tube  82  and is disposed about the interiorly disposed end of calibration tube  82 , and collar  100 , connected to the open end of lower portion  89   a . Calibration tube  82  houses a series of electrical contacts  94  which electrically communicate to interior surface  96  if calibration tube  82 . Engagement rod  86  slides within calibration tube  82 , extendable towards a vehicle in use, as described with respect to device  10  of  FIG. 1 . Disposed about the inner, or proximal end of engagement rod  86 , is at least one electrical conducting surface  102  (illustrated with stippling) electrically contactable with electrical contacts  94  inside calibration tube  82 , whereby at least one circuit may be formed as engagement rod  86  slides within calibration tube  82 . 
     A circuit is thus formed from a power supply, represented in  FIG. 6  as battery  104  or alternatively an electrical connection  106 , either supply disposed about or within device  90  in a manner known in the relevant art. In one embodiment, connection  106  is made to the electrical system of vehicle  12 , as by an interposed socket (not shown) associated with the usual hitch electrical connection, in order to supply operating power. The circuit, which may be either positive or negative ground, comprises a loop, for each indicator light  92 , from power source  104  or  106 , through light  92 , to one of contact  94 , through conducting surface  102 , to grounding conductor  106 , and finally back to power source  104  or  106 . 
     With reference to  FIG. 6 , engagement rod  86  is illustrated fully inserted within calibration tube  82 , whereby all lights would be lit, indicating a stop condition. Lights  92  may advantageously be of different colors, to provide additional information to the driver regarding longitudinal proximity. Further, indicator means  40  may also optional be illuminated, either at a stop position, or at all times. 
     In deployment, device  90  is first calibrated in a manner similar to the manner of device  10  of  FIG. 1 , in that hitch  18  and coupler  30  are first positioned longitudinally aligned, preferably oriented as they would normally be, just prior to being coupled. In the embodiment of device  90 , however, engagement rod  86  is inserted within calibration tube  82  substantially as illustrated, so that all lights are lit. Calibration tube  82  is then slid within lower portion  80   a  until tip  28  contacts the vehicle. It may be necessary to reposition device  90  so that this may be accomplished. After calibration, calibration tube  82  and engagement rod  86  remain in position by frictional engagement. Calibration tube  82  may optionally be taped or otherwise secured in a calibrated position. The location of either device  10  or device  90  may be indicated on the trailer by tape, paint, or other marking, so that calibration need not be repeated when using the same trailer and vehicle. Prior to the next use of device  90 , engagement rod  86  is fully extended, so that as vehicle  12  pushes engagement rod  86  within calibration tube  82 , lights  92  will be successively illuminated as each subsequent contact  94  is grounded through ground  106  and conducting surface  102 . 
     With further reference to  FIG. 6 , in one embodiment in accordance with the invention, upper portion  106  is optionally provided to be slideably retained upon main tube  80 , whereby the height of lights  92  and indicator  40  may be adjusted for optimal viewing from vehicle  12 . In the absence of portion  106 , lights  92  and indicator  40  are mounted upon upper portion  108  of main body  80 . 
     It should be understood that contacts  94  may also take the form of switches, wherein it would not be necessary to ground engagement rod  86 . In this embodiment in accordance with the invention, the switch actuator (not shown), such as the roller of a microswitch, extends into the interior of calibration tube  82 , and is pushed to activate a switch by passage of engagement rod  86  within calibration tube  82 . This may be further understood with reference to  FIG. 7 , in which calibration tube  32  slides in connection an upper extending portion  108  of main body  20 . 
     With reference to  FIG. 7 , in yet another embodiment of the invention, flexible connector  36  is operative to move actuator  110  which engages at least one switch  94 , operative to successively illuminate lights  92 , in connection with wires and a power supply (not shown), as described with respect to  FIG. 6 , or as is otherwise known in the relevant art. Movement and use of calibration tube  32  operates substantially as described with respect to  FIG. 1 , however in this embodiment, switches  94  move in connection with calibration tube  32 , and thus the point of engagement with actuator  110  changes, and thus device  10  may be calibrated as described above. 
     It should be understood that, in addition to lights or visible painted indicia, a recorded spoken message or audible alarm may be used to indicate approach to a hitching position, or the attainment of a hitching position. Actuation of the audible signal is achieved by actuation of switches in the embodiments of  FIG. 6  or  7 , or by actuation of a switch (not shown) connected to calibration rod  32 , and actuated by movement of indicator rod  34 , in the embodiment of  FIG. 1 . 
     In accordance with a further embodiment of the invention, as shown in  FIG. 8 , one or more of device  10  may be placed away from the forward end of the trailer, or at the rearwards end of the trailer in particular, whereby lateral alignment is facilitated. This is particularly helpful where the trailer is low and cannot be viewed in either side mirror, or cannot be viewed in the rear view mirror. In this use, engagement rod  26  is advantageously pushed inwardly until the indicator rod  34  indicates a stop position, for maximum visibility of the device. During backing, as the trailer veers to the left or right, the indicator rod may be observed relative to a fixed point on the vehicle, such as marker  48 . Since the rearward vehicle is farther from the marker, small changes in lateral alignment will appear more pronounced. 
     In addition, when backing the trailer into a close ended area, such as a garage, or against a building or other obstruction, it is easier to observe the distance between the rear of the trailer and the obstruction. If only one device  10  is available, it may be removed and attached at the back of the trailer for backing, as illustrated in  FIG. 8 . In accordance with the invention, this is facilitated if the attachment means is by magnets  24 . 
     If there is only one device  10  available, it may be advantageous to move it to the rear of the trailer after hitching is complete, when it is desired to drive or back up the connected vehicles. If multiple devices are available, one could be used for hitching, and one or more additional devices for lateral alignment at the rear of the trailer. Device  10  may also be left in place during driving, for convenience, or for further alerting following drivers to the presence of the trailer, and in particular, a low trailer. 
     With reference to  FIG. 9 , in another embodiment in accordance with the invention, device  10  is integrated into the trailer structure, such as within the trailer draw bar  22 . Main body  20  may be replaced in whole or in part by draw bar  22 . Collar  46 , in  FIG. 9 , maintains alignment and smooth movement of engagement rod  28  within draw bar  22 , and alongside coupler  30  after emerging from draw bar  22  or trailer  14  body. This embodiment provides durability and protection for device  10 , and may be incorporated into new trailer construction as a convenience and incentive for trailer purchasers, or may be retrofitted to existing trailers. 
     In accordance with a further embodiment of the invention, main body  20  may be hinged to reduce the overall size of device  10 , to facilitate stowage. 
     All references cited herein are expressly incorporated by reference in their entirety. 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 invention and it is contemplated that these features may be used together or separately. Thus, the invention should not be limited to any particular combination of features or to a particular application of the invention. Further, it should be understood that variations and modifications within the spirit and scope of the invention might occur to those skilled in the art to which the invention 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 invention are to be included as further embodiments of the present invention.