Abstract:
A wheel chock restraint system which comprises a wheel chock having a base, a plurality of teeth extending outwardly from the base, the teeth extending in a first direction, and a locking member mounted within the chock, the locking member having a plurality of locking member teeth extending from a bottom thereof, the locking member teeth extending in a second direction generally opposed to the first direction, and an arrangement for moving the locking member in a generally vertical direction.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to wheel chocks, and more particularly to a wheel chock restraint system to engage the wheel of a truck to prevent it moving away from a location. 
       BACKGROUND OF THE INVENTION 
       [0002]    Vehicles such as semi trailers are often removed from locations at undesired moments. They can be stolen from a company yard, parking lot or truck stops. This situation can also happen at a loading dock. Some reports say that more than 30 billion dollars worth of goods disappear with stolen semi trailers. Some places secure their area with fences and gates, some may also have guards to help control the security. There are no reported systems to secure a specific vehicle in those areas. 
         [0003]    Loading and unloading operations are hazardous for forklift trucks entering and exiting a truck trailer. It is imperative that a truck remain immovably docked at the loading dock to prevent moving fork lifts from falling through the space created if a truck trailer moves. 
         [0004]    There are two known types of restraint systems: ICC bar restraint systems to prevent the truck from moving away from the dock, and wheel restraint systems. However, while the first system is suitable for a majority of trailers, there are several configurations of trucks that cannot be secured by such ICC bars. Besides, ICC bars are built to absorb a rear impact with another truck and are not designed to resist a strong pulling force. In view of this fact, this system does not prevent the truck from moving away from the loading dock. The second category includes manual and mechanical chocks. Manual placement of a chock presents different problems, such as chocks which may be displaced, damaged, lost, or stolen. They also may slip on icy, oily or dusty surfaces and are often difficult to remove from their operational position because they may be wedged very tightly under the trailer&#39;s wheel. Very often, chocks are removed before the loading operation is complete, thus creating a dangerous situation where the vehicle can depart prematurely or slide away from the dock as heavy fork lifts enter the trailer. Also, docked trailers can be stolen mostly after business hours. In a lot of cases, trailers are a target for theft as they are loaded with valuables. 
         [0005]    Mechanical wheel chock systems are more effective than manual chocks. They also are not very easy to service and often have to travel a substantial distance from storage into operative position. Other mechanical chocks which are mounted on the surface may be affected by winter and become an obstacle during snow removal. They also may interfere with the tail gate of the truck or truck&#39;s undercarriage, and are inoperable with many types of vehicles. 
         [0006]    One mechanical wheel chock restraint system known in the art and which is effective is that disclosed in U.S. Pat. No. 7,032,720 the contents of which are hereby incorporated by reference. 
       SUMMARY OF THE INVENTION 
       [0007]    It is an object of the present invention to provide a wheel chock restraint system to prevent the movement of a vehicle away from a location. The location may be a loading dock or other locations such as a yard, parking lot or truck stop, wherein it is desired to lock a vehicle in a fixed location. 
         [0008]    According to one aspect of the present invention, there is provided a wheel chock restraint system comprising a wheel chock having a base, a plurality of teeth extending outwardly from the base, the teeth extending in a first direction, a locking member mounted within the chock, the locking member having a plurality of locking member teeth extending from a bottom thereof, locking member teeth extending in a second direction which is generally opposed to the first direction and means for moving the locking member in a generally vertical direction. 
         [0009]    The present invention utilizes a secondary locking member which acts in a counter direction to the primary chock. The secondary chock may be locked in position by suitable means so as to prevent movement thereof. Since it operates in a direction different than the primary chock, it provides a strong securement for the vehicle. 
         [0010]    The prime advantage of one embodiment of the present invention pertains to the use of the system as an anti-theft device. When operated by a suitable power source (e.g. electric, hydraulic, pneumatic, et cetera) it functions to prevent theft of the trailer (or other vehicle). Naturally, a second chock may be utilized to immobilize the wheel. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Having thus generally described the invention, reference will be made to the accompanying drawings illustrating an embodiment thereof, in which: 
           [0012]      FIG. 1  is a schematic side view of a wheel chock restraint system; 
           [0013]      FIG. 2  is a perspective view thereof; 
           [0014]      FIG. 3  is a side elevational view of a slightly modified wheel chock restraint system; 
           [0015]      FIG. 4  is a perspective view of a modified wheel chock restraint system according to the present invention; 
           [0016]      FIG. 5  is a sectional view taken along the lines  2 - 2  of  FIG. 4 ; and 
           [0017]      FIG. 6  is a view similar to  FIG. 5  illustrating operation of the system. 
           [0018]      FIG. 7  is a view similar to  FIG. 6  of an alternative embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    Referring to the drawings in greater detail,  FIGS. 1 and 2  show a first embodiment of a wheel chock  10  attached to a wheel chock support means. A movable arm arrangement consists of a front arm  12  pivotally attached to a rear arm  14 . Rear arm  14  is pivotally attached to a loading dock  16  by means of a pivot or bracket  18 . A tension means such as an extension spring  20  is attached by one end to a bracket  18  and by another end to an upper portion of the front arm  12  by means of a cable or steel rod  22 . Bracket  18  allows the arms  12 ,  14  to be rotated left and right and up and down, and to move it into storage position, in close proximity to the dock face (not shown) when not in use. 
         [0020]    A locking member is fixed on the ground in the vicinity of the loading dock and comprises an elongated plate  26  long enough to spread at least under one axle of a truck  24  during loading operation to facilitate a proper engagement of wheel chock  10  with the plate  26 . A base portion of the chock  10  is provided with a first engagement means or teeth  28  which are adapted to cooperate with the corresponding second engagement means or stoppers  30  located on plate  26 . 
         [0021]    Once the truck  24  is backed to the dock  16 , the truck driver manually sets the chock  10  by means of a handle  32  mounted on the front arm  12  to engage the chock  10  with a wheel  34 . The spring  20  attached from the bracket  18  to the upper portion of front arm  12  by means of cable  22  assists the manipulation by the driver of the movable arms  12 ,  14 . In this case, on one hand the retention force created by engagement of teeth  28  of chock  10  and stoppers  30  of the plate  26  is directed away from the loading dock  16  and prevents the chock  10  from sliding away from the wheel  34  of the truck  24  when the truck makes attempts to depart prematurely from the dock  16 . On the another hand, arms  12 ,  14  create an engagement force directed towards the loading dock  16  and presses chock  10  against the wheel  34 . Such a combination of two forces ensures a secure positioning of truck  24  during loading and unloading. 
         [0022]    Front arm  12  is pivotally attached to the chock  10  by means of a lower joint  36  and front arm  12  is pivotally connected to rear arm  14  by means of upper joint  38 . It should be emphasized that upper joint  38  may be of any possible configurations, such as a universal joint, bracket with a pivot or any other means which facilitates effortless pivoting of both arms. The most important feature is the fact that spring  20  is attached to the upper portion of the front arm  12 . Such arrangement allows very easy manipulation of the system because the more arm A extends, the more spring  20  pulls and consequently chock  10  becomes easier to move due to the leverage effect. However, the present invention is not restricted to the use of a spring and any other tension means may be used instead to the same purpose. 
         [0023]    Bracket  18  is attached to the dock face  40  by means of an anchor plate  42 . The engagement means of the chock comprises a plurality of angled teeth  28  extending downwardly from the base portion of the chock  10 . Engagement means of the plate  26  comprises a plurality of extending upwardly stoppers  30 . It is understood that any other possible equivalents may be used for the same purpose. In use, chock  10  is preferably positioned in such a way that teeth  28  are directed away from the loading dock  16 . 
         [0024]    Chock restraint system of  FIG. 1  is also provided with different kinds of sensors which facilitate secure loading and unloading procedures. A sensor  48  is installed on the bracket  18  to detect the extending movement of the arms  12 ,  14  during placement of the chock  10  under the wheel  34 . Sensor  44  installed on the chock  10  is provided to detect the presence of the wheel  34  at the moment said wheel engages the chock. Sensor  54  may be installed on front arm  12 . When the arm is removed from storage position, sensor  48  will send a signal to illuminate a visual indicator  46  to warn the dock workers and drivers. Visual indicator  46  will be also illuminated in response to both sensors  48  and  44  to ensure that the arm A is utilized and that the wheel  34  is properly engaged. Detecting sensors could be of many different types, such as non-contact sensors (photocell), mechanical detectors with contact arm, et cetera. 
         [0025]    Truck presence detector  50  may be installed around the dock to detect a vehicle when arriving in the vicinity of the dock face  40 . Such detector may also be of contact or non-contact (photocell) arrangement, and is preferably designed to sense when the vehicle is a few inches from the dock. Using the control panel  52 , the vehicle detector  50  can be interlocked with other sensors, such as a restraint sensor  44  or  48  and a dock leveller sensor  56 . Movement of the truck during loading and unloading operations can trigger a loud alarm  58  to make the truck drivers and fork lift operators aware of danger. A loading entrance  16  is provided with a dock seal  60 , dock bumper  62  and interior lights  64 . 
         [0026]    In operation, when the truck backs into position with loading dock  16 , wheel  34  rolls over the elongated plate  26 . Once the truck  24  is backed up to dock  16 , the truck driver will manually set the chock  10  by means of handle  32  mounted on the front arm  12  to engage with the wheel  34 . The spring  20  attached from the bracket  18  to the upper portion of the front arm  12  by cable  22  will allow easy handling. The dock leveller  56  spans the gap between the bed of the truck  24  and the floor to allow forklifts to go in and out of the truck  24 , which is backed to the dock  16  against the dock bumper  62 . 
         [0027]    The sensor  54  or sensor  44  will sense the wheel  34  to ensure a proper positioning of the chock  10 , and the detector  50  of bracket  18  will signal the use of the extendable arm A. Proper positioning of the chock  10  is facilitated by articulations of bracket  18 , upper joint  38  and lower joint  36 . The truck presence detector  50  mounted on the bracket  18  will preferably sense the truck  24  when it is approximately 4-5 inches from the dock bumper  62 . In case the truck  24  will start to move away during the loading operation, dock leveller detector  56  is interlocked with the dock leveller  27  together with the truck presence detector  50  will trigger alarm  58 . All following detectors  44 ,  48 ,  50 ,  54  and  56  are operatively connected to the control panel  52  which will illuminate lights  46  and  64  to indicate when the loading operation is safe. 
         [0028]    Chock  10  is preferably made from high tensile weather resistant galvanized steel which is many times harder than conventional steel. An all weather chock combined with a non-skid plate can provide 60,000 lbs of restraining force. 
         [0029]      FIG. 3  shows a second arrangement wherein instead of one spring there are used two springs  16   a  and  16   b.    
         [0030]    For both arrangements shown on  FIG. 1  and  FIG. 3  the attachment point of cable or rod  22  depends upon the length of the front arm  12 , weight of said arm  12  and chock  10  and the strength of the tension means. 
         [0031]    In the arrangement shown in  FIGS. 4 to 6 , there is provided a secondary restraint  70 . Secondary restraint  70  is mounted within primary wheel chock  10  and is secured at a pivot point  74 . A handle or lever  72  is utilized to move secondary chock  70  into and out of position. Thus, in  FIG. 5 , secondary chock  70  is in a disengaged position while in  FIG. 6 , it is in an engaged position. 
         [0032]    Lever  72  may be moved as indicated by the arrows in  FIGS. 5 and 6 . To move from the disengaged position of  FIG. 5  to the engaged position of  FIG. 6 , lever  72  is moved upwardly and a first arm  76 , which is pivotally connected to a second arm  80 , which in turn is connected to secondary restraint  70  will lengthen and cause teeth  82  of secondary restraint  70  to engage with the upper part of teeth  28  of primary chock  10 . 
         [0033]    Turning to the embodiment of  FIG. 7 , there is illustrated a power chock assembly which includes secondary restraint  70 . In this embodiment, a motor assembly  90  is utilized to operate secondary restraint  70 . This is advantageous with the use of the system as an anti-theft system. 
         [0034]    Motor assembly  90  can only be operated when authorized. This may include authorization by electrical signal, a key or any other suitable means including many known arrangements. Thus, greater control is maintained over the removal of chock  10 . Naturally, other than an electric motor, pneumatic, hydraulics, hand leverage, et cetera may be utilized both for the locking and unlocking motions. 
         [0035]    It will be understood that the above described embodiments are for purposes of illustration only and that changes and modifications may be made thereto without departing from the spirit and scope of the invention.