Patent Publication Number: US-2005133315-A1

Title: Vehicle restraint system and method

Description:
FIELD OF THE INVENTION  
      The present invention relates generally to a vehicle restraint and a method for restraining vehicles. More particularly, the present invention relates to a wheel stop device and method for restraining trucks and trailers at a loading dock.  
     BACKGROUND OF THE INVENTION  
      Freight vehicles such as trucks and tractor trailers are often loaded and unloaded at a loading dock. Often at the loading dock, a dock leveler will be operated to form a bridge between the dock and the bed of the truck. Across this bridge, workers and material handling equipment such as fork trucks will pass to load or unload the vehicle. The bridge is formed by the dock leveler supported at one end by the bed of the vehicle and at the other end by the frame of the dock leveler. Movement of heavy loads starting and stopping on the bed of the vehicle creates forces that can cause the vehicle to move away from the loading dock. In addition, miscommunication between a dockworker inside, and a truck driver outside, can lead to the vehicle moving away from the loading dock. For example, if the vehicle were to pull away from the loading dock and leave the dock leveler unsupported at the end formerly supported by the vehicle bed, the dock leveler would fall. The unexpected movement of the trailer and subsequent fall of the dock leveler can have undesirable results for dockworkers on the dock leveler or in the trailer. As a result, it is important that vehicles not move away from the loading dock until the dock leveler and trailer has been cleared of workers and material handling equipment.  
      The need to prevent a vehicle from moving during loading and unloading operations has been addressed by a variety of different techniques. The most basic is the wheel chock, a wedge placed in front of the wheels of the truck. While simple, they are often misplaced, dislodged, or slip. Because of these deficiencies, a class of truck restraints that engage the ICC bar of the trailers has been designed and has achieved commercial success. While in most cases effective, there exist trailers with missing or damaged, or very low ICC bars, or those with rear mounted power tailgates that prevent ICC bar trailer restraints from being used effectively. Given these limitations of the ICC bar type trailer restraints, another type of truck restraint that does not rely on the ICC bar has been introduced. This type creates a barrier to the wheels of the trailer after the trailer has been positioned at the loading dock. Some of these wheel dependent systems are buried in the driveway and may be expensive to install and difficult to service. Some of these are above ground systems are configured to be driven over. Continuous driving over of the system over time can cause the systems to get damaged by vehicles while being positioned for loading and unloading. Portions of the above ground systems interfere with powered tailgates during loading and unloading.  
      Accordingly, it is desirable to provide a method and apparatus that will restrain a vehicle such as a truck or tractor trailer from moving away from a loading dock at an inappropriate time. The device should be easy to install and service, store out of the way of vehicles moving into position for loading and not interfere with powered tailgates during loading and unloading.  
     SUMMARY OF THE INVENTION  
      The foregoing needs are met, to great extent, by the present invention, wherein in one aspect an apparatus is provided that in some embodiments restrains a vehicle and prevents it from moving away from a loading dock while mounting on the drive surface and storing out of the plane of the trailer.  
      In accordance with one embodiment of the present invention, a vehicle restraint is provided. The vehicle restraint includes a track, a carriage configured to move along the track, and a wheel block pivotally mounted to the carriage to move between non-wheel blocking position where the wheel block is substantially over or under the track, and a blocking position.  
      In accordance with another embodiment of the present invention, a vehicle restraint is provided. The vehicle restraint includes means for guiding, means for carrying configured to move along the guiding means, and means for blocking a wheel carried by the carrier means, wherein the means for blocking pivots between a non-blocking position wherein the wheel block is substantially over or under the track and a blocking position adjacent to a vehicle wheel to be blocked.  
      In accordance with another embodiment of the present invention, a method of restraining a vehicle is provided. The method includes a moving a carriage along a track to a position adjacent to a wheel to be blocked, pivoting a wheel block mounted to the carriage from a position adjacent to a wheel to a position blocking the wheel.  
      There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.  
      In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.  
      As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view illustrating truck tires parked next to a loading dock and adjacent to a wheel blocking system in accordance with the invention. The tractor trailer normally associated with the tires is not shown in order to provide more clarity to the drawing.  
       FIG. 2  is a perspective view of the embodiment of the invention shown in  FIG. 1  where the carriage has moved out of the housing.  
       FIG. 3  is a perspective view of the embodiment of the invention of  FIG. 1  illustrating the wheel block attached to the carriage contacting the wheel.  
       FIG. 4  is a perspective view of the embodiment of the invention of  FIG. 1  illustrating the wheel block pivoting against the wheel as the carriage continues to move.  
       FIG. 5  is a perspective view illustrating the embodiment of the invention of  FIG. 1  showing the wheel block in the blocking position.  
       FIG. 6  is a perspective view of an embodiment of the invention illustrating the carriage attached to the track and the wheel block in a non-blocking position.  
       FIG. 7  is a perspective view of an embodiment of the invention illustrating the carriage attached to the track and the wheel block in a blocking position.  
       FIG. 8  is a side view of an embodiment of the invention showing the track, the carriage attached to the track and the carriage motor.  
       FIG. 9  is a partial enlarged view of the portion labeled  9  in  FIG. 8 .  
       FIG. 10  is a partial enlarged view of the area labeled  10  indicated in  FIG. 8 .  
       FIG. 11  is a partial enlarged view of the area labeled  11  indicated in  FIG. 8 .  
       FIG. 12  is a perspective view of an alternate embodiment of the invention illustrating a sensor arm attached to the carriage mounted on the track.  
       FIG. 13 . is a perspective view of an alternate embodiment of the invention illustrating the carriage mounted on the track and the wheel block in a partially engaged position.  
       FIG. 14  is a top view of an alternate embodiment of the invention illustrating the carriage mounted on the track carrying a wheel block and a sensor arm.  
       FIG. 15  is a top view of an alternate embodiment of the invention illustrating the sensor arm engaging a wheel and a wheel block in a partially engaged position with the wheel.  
       FIG. 16  is a perspective view illustrating an alternate embodiment of the invention illustrating the sensor arm in an engaging position. 
    
    
     DETAILED DESCRIPTION  
      The invention will now be described with reference to the drawing figures in which like reference numerals refer to like parts throughout. An embodiment in accordance with the present invention provides a vehicle restraining device that restrains a vehicle by blocking a wheel associated with the vehicle. Another embodiment of the present invention provides a method of restraining a vehicle by blocking a wheel associated with the vehicle.  
      A preferred embodiment of the present inventive apparatus is illustrated in  FIG. 1 . A vehicle restraint system  20  is shown next to a loading dock  22 . The vehicle restraint system  20  is mounted on a driveway  24 . Adjacent to the vehicle restraint system  20  and located on the driveway  24  are wheels  26 . The truck itself or trailer having the wheels is not shown in order to more clearly illustrate the vehicle restraint system  20  and its surrounding environment.  
      The loading dock  22  includes dock floor  28  and often includes a pit  30  in the dock floor  28 . The pit  30  is often used for mounting a dock leveler. In operation, a vehicle is backed to the loading dock  22  and is positioned with its wheels  26  positioned adjacent to the vehicle restraint system  20  as shown in  FIG. 1 . The invention may be used in applications where there is no pit or dock leveler.  
      The vehicle restraint system  20  includes a track  32  mounted onto the driveway  24 . At one end of the track  32  there is a drive system  34 . The drive system  34  includes a drive motor  36 . At the other end of the track  32  is a housing  38 . When the vehicle restraint system  20  is not in use, a carriage  40  (shown in  FIG. 2 ) is stored within the housing  38 .  
      In operation, a trailer backs in to a loading dock  22  until the rear of the trailer is positioned against resilient bumpers mounted on the dock face. Once the vehicle wheels  26  are in position (as shown in  FIG. 2 ), an operator will actuate a controller  99  (shown if  FIG. 1 ) that is operatively connected to the vehicle restraint system  20 , to engage the vehicle restraint system  20 . The vehicle restraint system  20  will move the carriage  40  out from the housing  38 . The carriage  40  will move along the track  32 . The carriage  40  carries a wheel block  42 . The wheel block  42  is pivotally connected to the carriage  40  with a pivot pin  44 . In some embodiments of the invention, the wheel block  42  will be substantially parallel to the track  32  when the wheel block  42  is not engaged to the wheel  26 . In other embodiments of the invention, the wheel block  42  will be substantially parallel to the track  32  when the carriage  40  is located in the housing  38 , but as the carriage  40  moves out of the housing  38  the wheel block  42  will move to a non-parallel position with the track  32  (for example, about 10° off parallel) via a biasing member and will be in a position ready to engage the wheel  26 . (The position shown in  FIG. 2 ). While the embodiments shown illustrate the wheel block  42  located substantially above the track  32  when in the non-blocking position, other embodiments of the invention may include the wheel block  42  located below an elevated track  32  when in the non-blocking position.  
      In some embodiments of the invention, when the carriage  40  moves back into the housing  38 , to the stored position, the wheel block will contact the side of the housing  38  and retract to a position substantially parallel to the track  32 . In other embodiments of the invention, when the carriage  40  moves back into the housing  38  to the stored position, the wheel block will contact an independent feature such as a guide not part of the housing and retract to a position substantially parallel to the track  32 .  
       FIG. 3  illustrates the carriage  40  moving along the track  32  to a position where the wheel block  42  starts to engage the tire  26 .  
       FIG. 4  illustrates the carriage  40  continuing to move along the track  32  and the wheel block  42  continues to pivot as it is engaged with the wheel  26  to a position approaching approximately perpendicular to the track  32 .  
       FIG. 5  illustrates the blocking position of the wheel block  42 . The carriage  40  has moved along the track  32  enough to cause the wheel block  40  to pivot to its full extent against the wheel  26 . In some embodiments of the invention, the carriage  40  will continue to move along the track  32  and urge the wheel block  42  against the wheel  26 . The urging of the wheel block  42  against the wheel  26  will cause the carriage  40  to achieve a slight skew position with respect to the track  32 .  
      For example, in some embodiments of the invention, the wheel block  42  will engage the wheel  26  and swing out to a position about perpendicular with the track  32 . The carriage  40  will continue to travel down the track  32  until the wheel block  42  has moved a small angle beyond perpendicular with the track  32 . In other embodiments of the invention the wheel block  42  will block the wheel  26  while in a position other than near perpendicular with the track  32 .  
      A sensing device such as a limit switch or other suitable device will be activated when the wheel block  42  has achieved its full blocking position. The sensing device will send a signal to the controller  99  (shown in  FIG. 1 ) shutting off the drive motor  36 . The interface pressure between the wheel block  42  and the tire  26  will cause the carriage  40  to become slightly askew with respect to the track  32 . This skewed attitude between the carriage  40  and track  32  will cause friction. The friction will aid in anchoring the carriage  40  to the track and preventing the wheel  26  from moving away from the loading dock  22  during normal loading dock operations such as loading and unloading the trailer with the wheel block  42  in the engaged position as shown in  FIG. 5 . In other embodiments of the invention, the drive system  34 , which will be explained in more detail below, will also anchor the carriage  40  in position during normal loading dock operations with the wheel block  42  in the engaged position.  
       FIG. 6  is an isometric view of the track  32 , carriage  40  and wheel block  42  according to a preferred embodiment of the invention. The wheel block  42  is pivotally mounted to the carriage  40 . The wheel block  42  is attached to the carriage  40  by hinge pin  44  and pivots about an axis extending through the center of the hinge pin  44 .  
      Once the wheel block  42  engages a tire  26  the carriage  40  will continue to move causing the wheel block  42  to pivot to a blocking position with respect to wheel  26 . In some embodiments of the invention, the carriage  40  will continue to move along the track  32  through and past the position where the wheel block  42  contacts the tire  26 , thus canting the carriage  40  with respect to the track  32 .  
      The wheel block  42  is equipped with an engaging plate  46 . The engaging plate  46  will engage the stop  48  mounted on the carriage  40  when the wheel block  42  has engaged the tire  26  and swung the wheel block  42  to a blocking position as shown in  FIG. 7 .  
      To facilitate engaging the wheel block  42  with a tire  26 , a roller  50  is provided on the end of the wheel block  42 . The roller  50  is allowed to roll about an axle  52  and is mounted on the end of the wheel block  42 . As the wheel block  42  approaches the tire  26 , the roller  50  will roll along the surface of the tire  26  as the carriage  40  moves forward and the wheel block  42  begins to swing. The roller  50  can reduce friction between the wheel block  42  and the tire  26  and aid in the wheel blocking  42  engagement with the tire  26 .  
       FIG. 7  illustrates the wheel block  42  in the blocking position. The engaging plate  46  is pressed against the stop  48 . A sensing device senses that the wheel block  42  is in the blocking position and sends a signal to the controller  99  (shown in  FIG. 1 ) which stops the drive motor  36 . The sensing device is configured to send the stopping signal to the controller  99  (shown in  FIG. 1 ) after the carriage  40  has urged the wheel block  42  against the tire  26  to the blocking position. In some embodiments of the invention, the blocking position will cause the wheel block  42  to urge against the tire  26  with some pressure. The force of the tire  26  pushing against the wheel block  42  will in some embodiments cause the carriage  40  to achieve a skewed position against the track  32 . The skewed position will create friction between the carriage  40  and the track  32  thus inhibiting the carriage  40  from moving along the track  32  as previously described.  
      In other embodiments of the invention, the drive system  34  will hold the carriage  40  in place preventing the tire  26  from moving away from the loading dock  22  during normal loading dock operations. In other embodiments of the invention, the driving system will include additional components such as a brake mechanism that will clamp the carriage  40  to the track  32  when the carriage  40  and wheel block  42  are in a blocking position. Still other embodiments of the invention will hold the carriage  40  in place using other suitable means.  
       FIG. 8  is a side view of the track  32 . The track  32  at periodic locations has track supports  54  supporting the track  32  on the driveway  24 . At one end of the track  32  is a drive system  34 . At the other end of the track  32  is the carriage  40  and the wheel block  42  in the home or rest position.  
       FIG. 9  is a detailed partial view of the area denoted as  9  in  FIG. 8 .  FIG. 9  illustrates the drive motor  36  and a carriage stop  56  mounted on the track  32 . The carriage stop  56  prevents the carriage  40  from obtaining an inappropriate position along the track  32  and perhaps damaging the drive system  34  or coming off the track  32 . Included in the drive system  36  is a chain sprocket  58 . A chain sprocket  58  drives the chain  60  which is operatively connected to the carriage  40 . The chain  60  is a continuous loop. The chain  60  is looped around the sprocket  58  at one end and around the idler pulley  62  at the other end of the track  32 . In some embodiments of the invention, the chain  60  is connected to a cable  66  (see  FIG. 11 ). The cable  66  makes up part of the loop described above and is connected to the carriage  40 . According to some embodiments of the invention, the sprocket  58  locks in position when the sensing device (previously described) sends a signal to the controller  99  (shown in  FIG. 1 ) that the wheel block  42  has achieved the blocking position. Selectively preventing the rotation of sprocket  58  through suitable means will prevent the chain  60  from moving and thus will lock the carriage  40  in place on the track  32 .  
       FIG. 10  is a partial detailed view of the portion marked as  10  in  FIG. 8 .  FIG. 10  shows the track  32  and a track support  54 . Also illustrated is a chain support  64 . The chain support  64  supports a lower portion of the chain  60  and/or cable and also may protect the chain  60  and/or cable from debris, snow, ice or other material that may foul or damage the chain  60  and/or cable. The upper portion of the chain  60  or cable is contained within the track  32 .  
       FIG. 11  is a detailed close-up view of the area indicated by numeral  11  in  FIG. 8 .  FIG. 11  shows the carriage  40  mounted to the track  32 . Below the track  32  is the idler pulley  62 . Around the idler pulley  62  is a cable  66  which is connected to the chain  60  shown in  FIG. 9 . Alternate embodiments of the invention include using a chain  60  as the whole loop, or using a cable  66  to comprise part of the loop as described above. The chain support  64  is shown in  FIG. 11  and provides the same protection/support function for the cable  66  as described for the chain  60 . The end of the track  32  is supported by a track support  54 .  
       FIG. 12  is an isometric view of another embodiment of the present invention. As shown in  FIG. 12 , the carriage  40  rests and travels along the track  32 . The wheel block  42  is mounted on the carriage  40  and is held substantially parallel to the track  32  when not in a blocking position. Other embodiments of the invention may not have the wheel block  42  be parallel to the track  32  when the wheel block  42  is not in the blocking position. A sensor arm  68  is mounted on the carriage  40 . The sensor arm  68  is configured to engage a tire  26 . Once the sensor arm  68  engages the tire  26  it will trigger the wheel block  42  to swing or pivot toward an operative position. At the end of the wheel block  42  is a feature  70  which is configured to engage the tire  26  and cause the wheel block  42  to pivot toward a blocking position without damaging the tire  26 . The feature  70  may be a bent portion of the wheel block  42  as shown, or a roller  50  as previously described.  
       FIG. 13  illustrates the wheel block  42  engaging the wheel  26  as the carriage  40  moves along the track  32 . The end feature  70  has engaged the tire  26  and is pivoting the wheel block  42  to the engaged position.  
       FIG. 14  is a top view of the embodiment shown in  FIGS. 12 and 13 . A sensor arm  68  is about to engage the tire  26 . The wheel block  42  is mounted on the carriage  40  and the wheel block  42  is in a substantially parallel position with respect to the track  32  when not in an engaged position.  
       FIG. 15  illustrates the sensor arm  68  engaging the tire  26 . The sensor arm  68  is starting to pivot on the carriage  40 . The pivoting action of the sensor arm  68  triggers a release mechanism operatively connected with the wheel block  42  causing the wheel block  42  to be released from its substantially parallel position to the track  32  and start to move towards a blocking position. A biasing member such as a spring pushes the wheel block  42  to a partially blocking position when the sensor arm  68  triggers the wheel block  42  release by the sensor arm  68  engaging a tire  26 .  
       FIG. 16  illustrates the sensor arm  68  attached to the carriage  40  by a sensor arm bracket  72 . Other embodiments of the invention may attach the sensor arm  68  by other suitable means.  
      In some embodiments of the invention, where a sensor arm  68  is used, the sensor arm  68  and the wheel block  42  are substantially parallel to the track  32  when the carriage  40  is in the stored position within the housing  38 . As the carriage  46  moves out of the housing  38  a biasing member such as a spring will move the sensor arm  68  to the engaging position ready to engage the tire  26  (a position extending out from the track  32 ).  
      The wheel block  42  is biased to move to an engaging position (the position shown in  FIG. 12 ). Alternatively, the wheel block  42  may remain in a non-engaging position until the sensor arm  68  triggers a release to allow a biasing member such as a spring to move the wheel block  42  to a wheel engaging position (the position shown in  FIG. 15 ).  
      When the carriage  40  is moving back to the stored position, the wheel block  42  and sensor arm  68  will contact the housing  38 . As the carriage  40  moves into the housing  38 , the contact with the housing will cause the wheel block  42  and sensor arm  68  to pivot to their stored positions (approximately parallel with the track  32  in the embodiment shown, but not necessarily parallel in all embodiments of the invention).  
      The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.