Abstract:
A combination trailer crank and locking mechanism. The device includes a crank portion having a handle portion separated from a coupler portion by a generally S-shaped body portion. When the coupler portion of the device is coupled with a rotatable shaft of a retractable leg assembly of a trailer, the crank portion facilitates the raising and lowering of the trailer&#39;s legs. The device also includes a locking portion which is connected to the crank portion in a transverse orientation. When the device is connected to the rotatable shaft of the trailer by the locking portion, the crank portion will abut an underneath side of the trailer and prevent rotation of the rotatable shaft, thereby preventing a person from being able to raise and lower the retractable legs of the trailer.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 U.S.C. §119(e) of provisional application No. 60/165,001, filed Nov. 12, 1999, bearing the same title. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to a device for raising and lowering retractable support legs of a semitrailer as well as preventing the raising and lowering of the retractable legs of a semitrailer. More particularly, this invention relates to a combination trailer crank and locking mechanism. 
     Semi-trucks and trailers or tractor trailer rigs for over the road trucking to haul cargo are well known. These units generally include a truck which is selectively coupleable to a trailer. The trailer generally has wheels at a rear end and is coupled with a rear end of the truck at a forward end. The trailer generally has retractable legs located near the forward end to support the forward end of the trailer when it is not coupled with the truck. 
     As is well known in the art, the retractable legs can be raised or lowered by rotating a rotatable shaft in the leg assembly, thereby raising or lowering the forward end of the trailer. The rotatable shaft is usually turned by a generally S-shaped hand crank. In use, the user can raise the front end of the trailer by extending the legs and thereby permit the user to back the rear end of the truck underneath the front end of the trailer to facilitate coupling. When the trailer is coupled with the truck and being pulled, the legs are generally in a fully retracted position. When the user wants to uncouple the trailer from the truck, the user can then raise the front end of the trailer up and uncouple the truck. 
     Because of the nature of over the road trucking, it is often necessary for truckers to leave uncoupled trailers in public places, such as truck stops and weigh stations. While the trailers are locked to prevent theft of the contents of the trailer, the entire trailer themselves are often stolen. Once the trailers are out of public areas, the thieves can take their time in breaking into the trailers. Additionally, apart from the value of the contents of the trailer, the trailers themselves are quite valuable. When these unhooked trailers are left in public places, there is nothing to prevent thieves with their own trucks from raising the trailer up, coupling it with their truck and driving off. 
     Therefore, there is a need for a device which prevents the raising and lowering of the retractable legs of a semitrailer. Additionally, there is need for such a device which is inexpensive to make, compact, and easy to use. The present invention overcomes the drawbacks of the prior art and fills these and other needs. 
     BRIEF SUMMARY OF THE INVENTION 
     In order to overcome the above-stated problems and limitations, and to achieve the noted objects, there is provided a combination trailer crank and locking mechanism. 
     In general, the device includes a trailer crank or crank portion having a locking portion extending therefrom. The crank portion has a coupler portion separated from a handle portion by a body portion. The body portion is generally S-shaped and permits the crank portion to be used as a hand crank when the coupler portion is coupled with the rotatable shaft of the trailer. 
     The locking portion generally extends outwardly from a side of the crank portion and is preferably a short tubular member with a transverse bore. When it is desirable to use the device as a locking mechanism, the locking portion is received on the rotatable shaft of the trailer portion. In this orientation, the crank portion is generally parallel to a longitudinal axis of the trailer. A pin which couples the device to the rotatable shaft is provided with a padlock type body on one end to prevent the pin from being removed from the coupling arrangement. 
     When the device is coupled with the trailer in the locking arrangement, the ends of the crank portion prevent rotation of the rotatable shaft for very far by abutting the underneath side of the trailer. In this arrangement, a would-be thief cannot rotate the rotatable shaft the multiple number of times necessary to raise and lower the front end of the trailer the amount required to facilitate coupling and uncoupling of the trailer to a truck. Additionally, the would-be thief does not have access to and cannot gain access to the end of the rotatable shaft to attach their own crank because the padlock type pin securely locks the device onto the end of the rotatable shaft. Accordingly, because the would-be thief cannot raise and lower the front end of the trailer, the trailer cannot be coupled with a truck and can therefore not be stolen. Additionally, the user can, apart from using the device to lock the retractable legs of the trailer in a set position, use the same device to facilitate the raising and lowering of the trailer. Accordingly, the present device provides an economical, compact, easy to use and sturdy means of preventing the theft of trailers. 
     Further objects, features, and advantages of the present invention over the prior art will become apparent from the detailed description of the drawings which follows, when considered with the attached figures. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     The objects and features of the invention noted above are explained in more detail with reference to the drawing, in which like reference numerals denote like elements, and in which: 
     FIG. 1 is a side view of the combination crank and locking mechanism of the present invention in use on a trailer in the cranking position; 
     FIG. 2 is a perspective view of the combination crank and locking mechanism of the present invention; 
     FIG. 3 is an enlarged view of the combined trailer crank and locking mechanism of the present invention taken generally around the area of numeral  3  in FIG. 1; 
     FIG. 4 is a side view of the combined trailer crank and locking mechanism of the present invention coupled with the trailer in the cranking position; 
     FIG. 5 is a side view of the combination trailer crank and locking mechanism of the present invention attached to the trailer in the locking position; 
     FIG. 6 is a side view of the combined trailer crank and locking mechanism of the present invention attached to the trailer in the locking position and abutting the underneath side of the trailer; and 
     FIG. 7 is a top view of the combined trailer crank and locking mechanism of the present invention coupled with the trailer in the locking position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawing in detail, and initially to FIG. 2, numeral  10  generally designates the combined trailer crank and locking mechanism device of the present invention. The device  10  has a crank portion  12  and a locking portion  14 . 
     The crank portion  12  includes a body portion  16 , a coupler portion  18 , and a handle portion  20 . The body portion  16  has a first section  22 , a second section  24 , and a third section  26 . The body portion  16  also includes a first end  28  and a second end  30 . The body portion  16  is preferably an elongate cylindrical member and has been illustrated as a bent tube or pipe. The first section  22  and the third section  26  of the body portion  16  are preferably straight and are generally parallel to each other. The second section  24  connects the first section  22  to the third section  26  and has a generally S-shaped configuration. 
     The coupler portion  18  is located adjacent the first end  28  of the body portion  16  and preferably includes a clevis or a U-shaped member  32 . The clevis  32  preferably has a first leg  34  and a second leg  36  spaced apart by a central portion  38 . The legs  34 ,  36  include bores  40  for receiving a pin or bolt  42 . The bolt  42  has a first end  44  and a second end  46 . The second end  46  in the illustrated embodiment includes a stop or flange  48 . The first end  44  is adapted to receive a padlock body  50 . It should be noted that while the bolt  42  is illustrated as being straight and including the flange  48 , it is within the scope of the present invention to have the bolt  42  contain a bend near the second end  46  sufficient to prevent the pin  42  from being removed during use. 
     The handle portion  20  is located adjacent the second end  30  of the body portion  16 . The handle portion  20  may, as best illustrated in FIGS. 2 and 4, take the shape of a short piece of tubing having an inner diameter which is slightly greater than an outer diameter of the body portion  16 . Additionally, the handle portion  20  may simply be a portion of the third section  26  of the body portion  16 . Further still, the handle portion  20  may be coupled with the body portion  16  in a manner which permits the handle portion  20  to freely rotate about a portion of the body portion  16  during use. 
     The locking portion  14  is preferably a projection or tang  52  that extends from the crank portion  12 . The locking portion  14  has a proximal end  54  and a distal end  56 . The locking portion  14  is preferably a short piece of pipe or tubing which thereby provides a passage  58  there through. The locking portion  14  is preferably coupled at its proximal end  54  to the second section  24  of the crank portion  12  as illustrated in FIG.  2 . Additionally, the locking portion  14  is preferably coupled to the crank portion  12  such that the locking portion is generally perpendicular to a plane which would contain the crank portion  12 . As illustrated in FIG. 2, the locking portion  14  is preferably also coupled with the crank portion  12  in a manner in which a longitudinal axis of the tang  52  aligns radially with the body portion  16 . The locking portion  14  also includes a through bore  60  that is generally radial with respect to the tang  52 . The through bore  60  is of a diameter large enough to receive the bolt  42  but smaller than the stop  48 . 
     In use, the device  10  may be used as a crank when attached in a cranking position as illustrated in FIGS. 1,  3 , and  4  or as a lock when attached in a locking position as illustrated in FIGS. 5,  6 , and  7 . In the cranking position, the device  10  is coupled to a rotatable shaft  62  which extends from a support leg assembly  64  of a trailer  66  having an underneath side  68 . The support leg assembly  64  includes at least one support leg  70  which has a fixed portion  72  and a movable portion  74  which cooperate in a telescoping fashion. The movable portion  74  of the support leg  70  is illustrated as terminating in a sand shoe  76 . 
     When the rotatable shaft  62  is rotated in a first direction, the movable portion  74  of the support leg  70  is lowered and the sand shoe  76  moves away from the underneath side  68  of the trailer  66 . This permits a user to raise a front end  78  of the trailer  66  to detach it from a semi-truck. Additionally, the support leg  70  permits the trailer to stand on its own without being coupled to a semi-truck. 
     When the rotatable shaft  62  is rotated in a second direction which is opposite the first direction, the movable portion  74  of the support leg  70  is retracted into the fixed portion  72 . This permits a user to raise the sand shoe  76  off the ground surface so the sand shoe will not contact the ground when the trailer is being pulled by the semi-truck. 
     When the device  10  is coupled with the rotatable shaft  62  in the crank position illustrated in FIGS. 1,  3 , and  4 , the user may freely raise and lower the front end  78  of trailer  66  by rotating the rotatable shaft  62  through turning or “cranking” the crank portion  12  of the device  10 . 
     After the user has coupled or uncoupled the trailer  66  to the semi-truck, the user may lock the rotatable shaft  62  in a desired position so that another person can not raise or lower the trailer  66  by moving the movable portion  74  in or out of the fixed portion  72  by attaching the device in the locking position. In this manner, the user of the device  10  can prevent theft of a trailer that is not coupled to a semi-truck by locking the support leg  70  in an extended position and/or prevent accidental damage to the support leg  70  while the trailer is pulled by locking the support leg  70  in a retracted position. 
     To switch from the cranking position illustrated in FIGS. 1,  3 , and  4  to the locking position illustrated in FIGS. 5,  6 , and  7 , the user, after positioning the sand shoe  76  the desired distance away from the underneath side  68  of the trailer  66 , first removes the pin  42  from the coupler portion  18  and the rotatable shaft  62 . Once the pin is removed, the user may rotate the device  10  until the locking portion  14  aligns with the rotatable shaft  62 . The device  10  is placed back onto the rotatable shaft  62  by way of the passage  58  receiving a portion of the rotatable shaft  52 . The pin  42  is then received in the through bore  60  such that the pin extends both through the through bore  60  and the rotatable shaft  62  thereby preventing the device from being pulled off of the rotatable shaft  62 . To prevent someone from removing the pin  42  from the trough bore  60 , the padlock body  50  is attached to the first end  44  of the pin  42 . 
     When the trailer is not attached to a semi-truck and the device  10  is coupled with the trailer  66  in its locking position, the device prevents someone from stealing the trailer in a number of ways. First, the would-be thief cannot raise or lower the front end  78  of the trailer to facilitate coupling the trailer to their semi-truck because the device  10  prevents them from attaching a crank of their own to the rotatable shaft. Second, even though the device  10  is coupled with the rotatable shaft  62 , the device limits rotation of the rotatable shaft  62 . In other words, because the crank portion  12  extends generally perpendicular from the locking portion  14 , when a would-be thief attempts to rotate the rotatable shaft  62  the crank portion  12  will abut the underneath side  68  of the trailer  66  and thereby prevent the would-be thief from rotating the rotatable shaft a full rotation. As illustrated in FIG. 6, when someone attempts to rotate the device  10  when coupled with the rotatable shaft  62  in the locking position, the coupler portion  18  contacts the underneath side  68  of the trailer and it prevents the crank portion  12  from continuing to rotate about the rotatable shaft  62 . 
     From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the invention. 
     Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative of applications of the principles of this invention, and not in a limiting sense.