Background Art: Owners of such automobiles as sport utility vehicles, pick- ups, and cars may elect to equip their vehicles with a forward- mounted snowplow to facilitate snow removal from a covered surface. While each type of vehicle has a different frame structure and bumper design which accommodates this frame structure, the most commonly used arrangement for attaching a snowplow blade to a vehicle involves pivotally connecting a frame extension below the front of the vehicle to an A-frame plus lift-mount assembly which support the blade. The lift- mount assembly generally comprises a hydraulic cylinder connected to one or more lift arms plus a chain or cable arrangement mounted above the vehicle frame. The lift-mount assembly serves primarily to vertically move and support the plow blade during both transportation of the blade and while actively plowing snow. Additionally, the A-frame is typically aligned with the vehicle frame below the front of the vehicle to provide proper blade alignment, and the A-frame generally includes a frame assembly supporting the blade with a latch locking assembly means used to lock the plow unit in place. A typical locking assembly, described for example in US Patent 6,363, 629, comprises a spring-loaded pin assembly with a spring biasing against the locking pin. In the locked position, the spring forces the pin through a corresponding aperture in a side gusset, thereby fixing a locking latch in place, while a lever prevents the pin from retracting out of the aperture in the gusset. When unlocked, however, the pin is retracted from the

aperture, allowing movement of the latch for engagement or disengagement of the hitch, and therefore the unit. Such detachment of the snowplow from the vehicle enables use of the vehicle for personal and/or work-oriented purposes other than snowplowing. Each latch in US Patent 6,363, 629 can have a safety lock, or preferably a single safety lock can be used, preferably in conjunction with the latch that is located on the same side of the apparatus as the lever, for operator convenience and to prevent accidental loss. Such assemblies do not, however, secure these units against theft.

A new snowplow unit is an expensive investment for a vehicle owner, both financially and in terms of installation and storage time; this is thus an investment that warrants protection. However, a snowplow, when removed from the vehicle and placed on the ground, is most vulnerable to theft because any vehicle with the appropriate coupling/mounting attachments can simply pull up to the plow, attach the unit to the vehicle, and then drive away. Additionally, even though a snowplow is in its most secure position when mounted on the vehicle, it could still theoretically be removed and stolen because neither the A- frame nor the lift-mount assembly provide a means to lock the unit securely to the assembly. Failing to have an independent means to lock the snowplow to the vehicle also increases the possibility of accidental loss of the unit.

Objects of the Invention and Industrial Applicability : Accordingly, it is a general object of the present invention to provide an apparatus, and method of use thereof, to lock a vehicle-mountable snowplow either directly onto a vehicle or in another secure and desired location.

It is an object of the present invention to provide an apparatus, and method of use thereof, to lock a vehicle- mountable snowplow either directly onto a vehicle or in another secure and desired location to prevent intentional theft or accidental dislodging of the plow.

It is a further object of the present invention to provide an apparatus, and method of use thereof, to lock a vehicle- mountable snowplow either directly onto a vehicle or in another secure and desired location which is of low cost to buy and manufacture, easy to implement, and useful with different snowplow-vehicle connection designs.

Summary of the Invention: Consequently, to achieve these and other aims and objectives, the present invention provides for a roughly J- shaped snowplow locking apparatus configured in such a way as to allow easy insertion into and extraction from the connecting pin cage of the A-frame lift-mount assembly and prevent the withdrawing of the connecting pin in the assembly, thereby precluding the insertion or removal of the plow connector and simultaneously locking the receptacle in the"closed"position.

A gripping tab is provided on the top surface of the main body of the apparatus to allow easy insertion and extraction. A covering face extends downwardly from the main body of the apparatus to cover the head of the connecting pin, thereby preventing the pin's movement out of the closed position. Holes are provided in parallel arms which extend downward from the main body of the apparatus through which a lock or chain may be inserted to contribute to the security of the mechanism. The apparatus is preferably manufactured from tempered steel; however, any salt-resistant high-strength and durable material,

such as weather-resistant plastic, may be used. Additionally, the apparatus may be so resized as to fit a wide variety of different designs of connecting pin cages, thereby preventing the removal either of a plow unit from a vehicle to which it is attached or a stored plow from being attached to an unauthorized vehicle.

Brief Description of the Drawings : FIGURES 1,2, and 3 show side, front, and top views, respectively, of the apparatus.

FIGURE 4 shows a typical snowplow unit with A-frame lift- mount assembly and a vehicle with mounting assembly attached.

FIGURE 5 shows a cross-sectional view not to scale of the connecting pin and cage mechanism into which the apparatus is inserted.

FIGURE 6 shows a top cross-sectional view not to scale of the apparatus inserted within the connecting pin cage.

FIGURE 7 shows a side view not to scale of the apparatus inserted within the connecting pin cage, secured by a lock.

FIGURE 8 shows a snowplow unit with A-frame lift-mount assembly attached by chain to a location other than a vehicle.

Detailed Description of the Invention: There is depicted in FIGURES 1 through 3 an apparatus 1 designed to be inserted into the connecting pin cage of a snowplow A-frame lift-mount assembly unit, this unit in turn permitting attachment of the snowplow to a vehicle. The roughly J-shaped apparatus 1 has approximate overall dimensions of 6 inches (") length by 6"height by 2"width, and the apparatus 1 may be manufactured either from salt-resistant metal, preferably tempered steel, or from weather-resistant plastic. The apparatus 1 is formed from a rectangular main body 2, and all other parts of the apparatus 1 may either be formed directly from the appropriate surfaces of the main body 2 or otherwise attached to the main body 2.

Two arms (interchangeably labelled 3) extend perpendicularly downwardly the same length from the lateral surfaces of the main body 2, these arms 3 being parallel to each other. Drilled completely through the lateral surfaces of the two parallel arms 3 are holes 4, these holes 4 being drilled at a centerline approximately 4-1/4"down from the topmost surface of the apparatus 1. The centerline of the holes 4 forms a locus of insertion 5 into which a securing means such as a lock or chain may later be inserted.

A covering face 6 which covers approximately two-thirds the length of the front surface of the main body 2 of the apparatus 1, and which is approximately one-eighth the length of the lateral surface of the main body 2 and one-third the length of the two arms 3, extends perpendicularly downwardly from the front surface of the main body 2 of the apparatus 1.

Rising perpendicularly upwardly from the precise center of the top surface of the main body 2, and running along the whole length of the top surface of the main body 2, is a tab piece 7.

This tab piece 7 may be as much as one-third the width of the top surface of the main body 2.

Turning to FIGURE 4, the snowplow 8 is connected to a vehicle 9 by an extended A-frame lift-mount assembly unit 10.

The assembly unit 10 is attached to the vehicle 9 through the placement of a pin through the assembly's hollow connecting pin cage 11 into a complementary vehicle connecting pin acceptor unit 12, which in turn is attached to a reinforced vehicle mount unit 13. As shown in FIGURE 5, drawn along the line A-A depicted in FIGURE 4, before the apparatus 1 can be used, the connecting pin 14 is to be inserted into the connecting pin cage 11 so that the head 14a of the pin 14 is flush or nearly flush with the outer surface lla of the connecting pin cage 14, and so that the pin 14 penetrates into the pin acceptor unit 12. In this position, the pin 14 is known as in the"closed"position.

In conjunction with the top view in FIGURE 6, then, the apparatus 1 is to be aligned with the connecting pin cage 11 such that the parallel arms 3 of the apparatus 1 are fitted into

the inner surfaces of the lateral surfaces lld of the connecting pin cage, and the covering face 6 of the apparatus 1 covers or at least partly covers the head 14a of the pin 14. This placement shall prevent either accidental or intentional removal or dislodging of the pin 14 from the closed position in the cage 11, thereby keeping the snowplow unit unable to be attached to another unauthorized vehicle. As can be seen also in conjunction with FIGURE 7, when inserted into the connecting pin cage 11, the tab piece 7 of the apparatus 1 projects above the top surface llc of the connecting pin cage 11 to allow for easy removal, and the parallel arms 3 of the apparatus 1 project downward from the bottom surface lib of the connecting pin cage 11 such that the holes 4 may be readily seen and may accept a securing means.

Depending upon where the snowplow owner decides to store the snowplow unit, the owner may insert a lock 15 into the holes 4 of the apparatus 1 should the snowplow remain fitted into the lift-mount assembly unit 10, or the owner may elect to store the snowplow unit not on a vehicle but attached to a post such as a tree, pole, or other location. Thus as depicted in FIGURE 8, a chain 16 may be used to wrap around a post 17, this chain 16 then locked to provide additional security. Through attachment of the apparatus 1 to the connecting pin cage 11, then, a snowplow unit is secure from accidental dislodgement off the vehicle 9, or theft whether or not attached to a vehicle.

The apparatus is fully removable and reusable so that a snowplow owner is able to move the snowplow from location to location (and subsequently relock it) or transfer the apparatus from one snowplow unit to another of similar design. The apparatus described herein was designed and manufactured to fit the FISHER MINUTE MOUNTS snowplow frame and mount assembly.

However, while this is the exemplary design expressed herein, other snowplow manufacturers have similar connecting pin cages with slightly different dimensions that the apparatus described herein may be easily resized to fit. Thus, while the present invention has been described in connection with exemplary

embodiments thereof, it will be understood that many modifications in both design and use will be apparent to those of ordinary skill in the art, and this application is intended to cover any adaptations or variations thereof. It is therefore manifestly intended that this invention be limited only by the claims and the equivalents thereof.