Abstract:
A lock for securing a lowered or non-lowered landing gear of a tractor trailer comprising two hinged interlocking halves secured by a keyed locking cylinder which has a pin intersecting apertures in flanges of the halves.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/162,127, filed Oct. 29, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to locks. More specifically, the invention is a lock for a landing gear handle of a tractor trailer, made up of two hinged parts configured to fit around the landing gear handle, and locked with a shaft-type keyed lock. 
     2. Description of Related Art 
     There is a need for a durable but relatively inexpensive lock to prevent theft of parked trailers in a drop yard or depot. Loaded trailers when left in a drop yard which uses yard trucks to move trailers about prevent the conventional use of air locks and King pin locks. The yard truck moves the trailers by lifting the trailer up with the use of hydraulic apparatus with the landing gear up or down. King pin locks are greasy and messy to use and store. 
     The related art of interest describes various locking means for hitches and landing gear of trailers, but none discloses the present invention. The related art will be discussed in the order of perceived relevance to the present invention. 
     U.S. Pat. No. 5,782,115 issued on Jul. 21, 1998, to Danny L. Judy describes an anti-theft security device for locking the dolly-leg crank arm of trailers with a unitary housing having a flattened locking bar traversing a slot in the housing and preventing the housing from being detached from the crank arm. The bar has an aperture on an end for a keyed lock from which extends a chain which wraps around the dolly leg and crank. The chain is wrapped around the crank handle, extends through two lock chain guide harness rings and ends on a welded ring on the bottom of the housing. The device is distinguishable for its external keyed lock and chain. 
     U.S. Pat. No. 5,775,139 issued on Jul. 7, 1998, to Fred J. Sellers describes a steel trailer hitch lock comprising a housing with a mounting ball on the base plate which has hinged to it two right-angled side locking plates which intermesh on top and lock with a locking pin and a cylinder lock. The trailer hitch lock is distinguishable for its limitation to locking trailer hitch balls. 
     U.S. Pat. No. 5,520,030 issued on May 28, 1996, to John e. Muldoon describes a gooseneck trailer locking apparatus is formed by a pair of elongated and telescoping members having a hitch ball and chain lock at one end for connection with the king pin of a gooseneck trailer. The other of the of the telescoping members is provided with a clevis element lockably closely surrounding the depending portion of a trailer leveling and supporting jack by a clevis arm and lock securing the clevis to the jack. The apparatus is distinguishable for its dissimilar structure. 
     U.S. Pat. No. 5,426,961 issued on Jun. 27, 1995, to Pierre Rimbaud et al. describes an anti-theft security device for trailers comprising a security lock integrated to a mechanism actuating the props of trailers. The mechanism acts mechanically by preventing the gears from meshing or by blocking a bevel gear and by disrupting the supply of electricity. The device is distinguishable for having moving mechanical elements and an electrical locking element. 
     U.S. Pat. No. 4,730,468 issued on Mar. 15, 1988, to Milton Becker describes a locking pin for a telescoping landing gear of a semi-truck trailer, which pin intersects and prevents the lower inner cylinder from retracting. The locking pin comprises a shank with a head and a cog on one end and a lock at the opposite end locked by a key. The locking pin device is distinguishable for its singular function and structure. 
     U.S. Pat. No. 5,904,342 issued on May 18, 1999, to Gregory A. Laarman describes a landing gear crank handle adapted to lock into a collapsed position, a partially extended position, and a fully extended position. The landing gear crank handle is distinguishable for being limited to a specific crank handle structure. 
     U.K. patent application Ser. No. 1,565,542 published on Aug. 23, 1977, for Ronald T. Blakelock describes a security device for a semi-trailer leg comprising a key operated lock mechanism located inside the upper leg to prevent the pinion shaft from rotating to raise or lower the lower leg. The security device is distinguishable for its internal locking mechanism. 
     None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. 
     SUMMARY OF THE INVENTION 
     The invention is a lock for securing a lowered or non-lowered landing gear of a tractor trailer comprising two hinged interlocking halves secured by a keyed locking cylinder which has a pin intersecting apertures in flanges of the halves. 
     Accordingly, it is a principal object of the invention to provide a locking device for immobilizing the landing gear of a tractor trailer whether it is extended or not to prevent theft. 
     It is another object of the invention to provide a locking device which immobilizes the landing gear of a tractor trailer even when the trailer is connected to the truck to prevent theft. 
     It is a further object of the invention to provide a locking device which houses the hinged portion of the crank handle to prevent theft. 
     Still another object of the invention is to provide a locking device which is hinged for housing the hinged portion of the crank handle and locked by a key to prevent theft. 
     It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an environmental, front elevational view of a lock installed on a tractor trailer landing gear according to the present invention. 
     FIG. 2 is a perspective view of the lock being installed. 
     FIG. 3 is a perspective view of an opened lock. 
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention illustrated in FIGS. 1,  2  and  3  is directed to a lock device  10  for preventing access to the landing gear of a tractor trailer whether it is lowered or not and whether the trailer is connected to the tractor or not. The crank handle  12  must be in a folded position relative to the dolly-leg crank arm  14  (FIG. 2) of the dolly-leg crank case. The lock housing  16  has a rectangular box configuration and is made of metal, preferably case hardened. The housing  16  consists of two mating but dissimilar halves  18  (front half element) and  20  (rear half element) joined by a metal hinge  22  having its legs welded to the inside of the housing  16  for increased tamper-proofing. 
     The rear half element  20  (FIG. 2) comprises a main rectangular wall portion  24  bounded by a stepped wall portion  26  on its right side joined by a channel  28  to a flange  30  extending out from the sidewall  32 . It should be noted that there is no wall opposite the stepped wall portion  26  on the front half element  18 . An aperture  34  is located on the flange  30  for cooperation with a locking pin (not shown) of the bar-shaped and notched locking cylinder element  36  locked by a key  38  (FIG.  3 ). 
     The front half element  18  (FIGS. 1 and 3) is designed to interfit the rear half element  20  and permit no access opening for prying open the lock device  10 . The L-shaped main wall  40  has an aperture  42  on the extended portion  44  which is aligned with aperture  34  for locking purposes. A rectangular wall portion  46  is connected by hinge  22  to the rectangular wall portion  24  of the rear half element  20 . An end wall  48  with a cutout portion  50  completes the structure of the front half element  18 . 
     The locking cylinder element  36  has a rectangular bar configuration (not shown entirely) with a notch or slot for accepting the portions of the front half and rear half elements  18 ,  20 , respectively, and to support a lock pin which would penetrate the apertures  34 ,  42 . Thus, the lock device  10  is securely attached to the crank handle  12  and the dolly-leg crank arm  14  to prevent the movement of the landing gear of a tractor- or semi-trailer. 
     It is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims.