Abstract:
A hood support for a vehicle having a hood moveable between open and closed positions is provided. The hood support includes a spring assembly disposable between the vehicle hood and another portion of the vehicle. The spring assembly is moveable into an extended position to accommodate movement of the hood into the open position and moveable into a compressed position to accommodate movement of the hood into the closed position. The hood support further includes a lock tube surrounding a portion of the spring assembly and moveable relative to the spring assembly. The lock tube is selectively actuatable between a locked position, wherein the lock tube secures the spring assembly in the extended position, and an unlocked position, wherein the spring assembly is permitted to be displaced into the compressed position.

Description:
BACKGROUND 
   Conventional heavy duty trucks have a large engine covering hood which tilts about a transverse pivot point located above the bumper to expose the engine for servicing. Although commonly made of lightweight materials, these hoods are nevertheless cumbersome to handle in part because of their heaviness and the relatively long moment arm between the center of gravity of the hood and the pivot axis. For example, the mass of the hood makes arresting its movement toward either the open or closed position a challenge. 
   A hood tilt assist mechanism is often disposed between the hood and a portion of the vehicle to slow the hood when it is moved into either the open or closed position. The hood tilt assist mechanism normally includes a counterbalancing device to control the movement of the hood, thereby assisting the user. The counterbalancing device may be an extension or compression spring, a cable, a shock-absorber, a gas spring, etc. 
   In addition to the hood tilt assist mechanism, the vehicle may also include an automatic locking device that secures the hood in the open position to prevent inadvertent closure of the hood and avoid injuring the operator. However, including a locking device separately from the hood tilt assist mechanism increases the number of assemblies within the truck. Moreover, many automatic lock designs include multiple moving parts, which increase assembly time and decreases production. Additionally, use of multiple moving parts within a lock causes the lock components to wear quickly and fail over time. 
   Thus, it is desired to provide a hood tilt assist mechanism having a simplified automatic locking system integrated therewithin. 
   SUMMARY 
   A hood support for a vehicle having a hood moveable between open and closed positions is provided. The hood support includes a spring assembly disposable between the vehicle hood and another portion of the vehicle. The spring assembly is moveable into an extended position to accommodate movement of the hood into the open position and moveable into a compressed position to accommodate movement of the hood into the closed position. The hood support further includes a lock tube surrounding a portion of the spring assembly and moveable relative to the spring assembly. The lock tube is selectively actuatable between a locked position, wherein the lock tube secures the spring assembly in the extended position, and an unlocked position, wherein the spring assembly is permitted to be displaced into the compressed position. 
   This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 

   
     DESCRIPTION OF THE DRAWINGS 
     The foregoing aspects and many of the attendant advantages of the present disclosure will become more readily appreciated by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
       FIG. 1  is an environmental view of a representative embodiment of a hood support shown in combination with a vehicle hood assembly; 
       FIG. 2  is a side planar view of the hood support of  FIG. 1  with portions removed for clarity and showing the hood support is shown in a first position; 
       FIG. 3  is a side planar view of the hood support of  FIG. 2 , showing the hood support in a second position; 
       FIG. 4  is a side planar view of the hood support of  FIG. 2 , showing the hood support in a third position; 
       FIG. 5  is a side planar view of the hood support of  FIG. 2 , showing the hood support in a fourth position; and 
       FIG. 6  is a side planar view of the hood support of  FIG. 2 , showing the hood support in a fifth position and the engine hood assembly in a closed position. 
   

   DETAILED DESCRIPTION 
   A hood support  10  constructed in accordance with one embodiment of the present disclosure is best seen by referring to  FIG. 1 . The hood support  10  is shown in combination with a heavy duty truck T having a cab C, a chassis or frame F, and a hood H. The hood H is pivotally coupled at its forward end to the frame F through a suitable hinge assembly A that is well known in the art. The hood H pivots about the hinge assembly A to move between open and closed positions. The hood support  10  is disposed between the hood H and the frame F and is adapted to control the movement of the hood H when it is moved between the open and closed positions. The hood support  10  also temporarily locks the hood H in the open position. 
   Referring now to  FIGS. 2 and 3 , the hood support  10  includes a spring assembly, or a spring strut  14  and a locking assembly  16  secured thereto. The spring strut  14  is adapted to slow the hood H as it is moved between the open and closed positions. The spring strut  14  may be any suitable off-the-shelf spring strut with the required spring rate to control the movement of the hood H between the open and closed positions. The spring strut  14  also has a suitable stroke length to position the spring strut  14  between the hood H and the frame F in both the open and closed positions. 
   The spring strut  14  includes a cylinder  22  that houses two counterbalanced springs  20  and  21 . The cylinder  22  of the spring strut  14  includes an upper end  78  ( FIG. 1 ) and a lower end  82  having an opening therein for slidably receiving a rod  18 . The rod  18  is slidably disposed within the cylinder  22  and operably coupled to each spring  20  and  21  through a piston  24  or other support member such that the springs  20  and  21  are compressible and extendible by the rod  18 . The rod  18  extends outwardly from the lower end  82  of the cylinder  22  and is received within a portion of the locking assembly  16 . The counterbalanced springs  20  and  21  extend and compress as needed to accommodate the movement of the rod  18  within the cylinder  22  and the overall extension or compression of the spring strut  14 . It should be appreciated that any other suitable spring assembly may instead be used, such as a dual direction gas spring or a compression or extension gas spring. 
   The locking assembly  16  includes a lock tube  26  that is adapted to receive the spring strut  14  therewithin. The rod  18  is received within a first tube end  30  of the lock tube  26  and extends downwardly into the lock tube  26 . The rod  18  passes through an opening in a second tube end  34  of the lock tube  26  and is thereafter received within a lower end fitting  70 . The lower end fitting  70  is adapted to pivotally mount the rod  18  to the frame F. The interior of the lock tube  26  is also of a diameter sufficiently large to receive the cylinder  22  therewithin, as shown in  FIGS. 4 and 5 . In this manner, when the spring strut  14  compresses a predetermined amount, the cylinder  22  is slidably receivable within the lock tube  26  to allow the spring strut  14  to fully compress and the hood H to close. Although the lock tube  26  is preferably cylindrical in shape, it should be appreciated that any suitable shape may be used, such as rectangular. 
   The lock tube  26  is movably secured to the spring strut  14  such that the lock tube  26  may rotate relative to the spring strut  14  when the hood H is moved between open and closed positions. Preferably, the second lock tube end  34  of the lock tube  26  is pivotally coupled to the rod  18  in any suitable manner, such as with a pin assembly  36  that passes through both the lock tube  26  and the rod  18 . The lock tube  26  may instead be pivotally coupled to the frame F in any suitable manner that allows the lock tube  26  to rotate relative to the spring strut  14 . 
   Referring to  FIG. 2 , the first tube end  30  of the lock tube  26  is angled to define an upper first tube end portion  38  and a lower first tube end portion  42 . Secured to the exterior of the lock tube  26  near the lower first tube end portion  42  of the first tube end  30  is a lock handle  46 . The lock handle  46  includes a tube mating portion  50  secured to the exterior of the lock tube  26  and a handle portion  54  extending upwardly therefrom. The tube mating portion  50  is secured to the exterior of the lock tube  26  in any suitable manner, such as by welding. The handle portion  54  extends upwardly from the lower first tube end portion  42  of the first tube end  30 . 
   The handle portion  54  includes a cylinder engaging surface  58  formed on the interior of the handle portion  54  and suitably contoured for engaging the cylinder  22  of the spring strut  14 . A magnet  62  is disposed within the upper end of the handle portion  54  and is substantially flush with the cylinder engaging surface  58 . The magnet  62  secures the cylinder  22  against the cylinder engaging surface  58  when the lock tube  26  is rotated and the lock handle  46  engages the cylinder  22  (See  FIG. 4 ). Thus, when the spring strut  14  compresses and the cylinder  22  is moved along the rod  18 , the cylinder  22  slides against the cylinder engaging surface  58 . The cylinder engaging surface  58  provides path that guides the cylinder  22  downwardly towards the lock tube  26 . 
   The handle portion  54  further includes a cam surface  66  formed at the bottom interior of the handle portion  54  that extends outwardly from the cylinder engaging surface  58  towards the lock tube  26 . The cam surface  66  is adapted to urge the cylinder  22  into the lock tube  26  as the cylinder  22  slides downwardly against the cylinder engaging surface  58 . Additionally, the cam surface  66  separates the cylinder  22  from the magnet  62  as the cylinder  22  slides downwardly to allow the cylinder  22  to be received within the lock tube  26 . 
   Referring back to  FIG. 1 , the lower end fitting  70  pivotally secures the rod  18  to the frame F. A similar upper end fitting  74  is secured to the cylinder upper end  78  for pivotally mounting the cylinder  22  to the hood H. The upper and lower end fittings  70  and  74  may be any suitable fitting assembly adapted to pivotally secure the rod  18  to the frame F and the cylinder  22  to the hood H. With the spring strut  14  of the hood support  10  pivotally secured to the frame F and the hood H, the hood support  10  accommodates the movement of the hood H when the hood H is moved between the open and closed positions. It should be appreciated that the hood support  10  may also accommodate the hood movement with the cylinder upper end  78  pivotally secured to the frame F and the rod  18  pivotally secured to the hood H. 
     FIGS. 1-6  show the movement and operation of the hood support  10  as the hood H is moved between the open and closed positions.  FIG. 6  shows the hood H in a closed position. When the hood H is in the closed position, the spring strut  14  is compressed due to the weight of the hood H, and the cylinder  22  is received within the lock tube  26 . 
   Referring to  FIG. 1 , the hood H is opened by lifting the rear portion of the hood H and rotating the hood H in a clockwise direction about the hinge assembly A. As the hood H is lifted into the open position, the spring strut  14  extends, and the cylinder  22  moves upwardly out of the lock tube  26 . To aid the operator, the springs  20  and  21  are preferably adapted to urge the hood H at least slightly into the open position while controlling the movement of the hood H. As the hood H is being opened, the spring strut  14  pivots at the lower end fitting  70  and the upper end fitting  74  to accommodate the clockwise rotation of the hood H about the hinge assembly A. The hood H is lifted until the center of gravity of the hood H pivots about the hood assembly A and the cylinder  22  is no longer received within the lock tube  26 , thereby placing the hood H in the open position. 
   Referring to  FIG. 2 , with the hood H in the open position, the hood support  10  is disposed between the hood H and the frame F at an angle such that the lock tube  26  rotates clockwise about the pin assembly  36  due to the gravitational effects on the lock tube  26 . The lock tube  26  rotates clockwise until the interior of the lock tube  26  engages the rod  18 . As such, the lock tube  26  is positioned against the rod  18  such that the upper first tube end portion  38  is situated substantially beneath the cylinder  22 , or in a locked position. With the lock tube  26  in the locked position, the spring strut  14  cannot compress. More specifically, the upper first tube end portion  38  of the lock tube  26  prevents the cylinder  22  from sliding downwardly along the rod  18 . Accordingly, the hood H is locked in the open position, thereby preventing any accidental closure and avoiding possible injury. 
     FIG. 3  depicts the hood H being moved towards the closed position with the lock tube  26  in the locked position. This may occur if, for instance, a strong wind blows against the hood H. The hood H rotates counterclockwise until the cylinder lower end  82  engages the upper first tube end portion  38 , or the spring-engaging portion, of the lock tube  26 . With the lock tube  26  in the locked position, the cylinder  22  cannot slide along the rod  14  to allow the spring strut  14  to compress and the hood H to close. As such, the hood support  10  is maintained in the open position. 
   Referring to  FIG. 4 , to unlock the hood support  10  and close the hood H, the operator grasps the lock handle  46  and pushes the lock handle  46  and lock tube  26  toward the spring strut  14  until the cylinder engaging surface  58  and the magnet  62  engage the cylinder  22 . The magnet  62  secures the lock handle  46  to the cylinder  22 , thereby preventing the lock tube  26  from rotating clockwise back into the locked position. 
   Referring to  FIG. 5 , the weight of the hood H as well as any external downward force exerted by the operator causes the spring strut  14  to compress in a controlled manner. As the spring strut  14  compresses, the cylinder  22  travels downwardly against the cylinder engaging surface  58 . The magnet  62  maintains contact between the cylinder engaging surface  58  and the cylinder  22  such that the lock tube  26  is maintained in the unlocked position as the spring strut  14  compresses. The spring strut  14  continues to compress and the cylinder  22  continues to travel downwardly against the cylinder engaging surface  58  until the cylinder engages the cam portion  66 . 
   When the cylinder lower end  82  engages the cam portion  66  and travels downwardly along the cam surface  66 , it is urged away from the lock handle  46  and towards the lock tube  26 . The cylinder lower end  82  travels along the cam surface  66  until the cylinder  22  separates from the magnet  62 . As such, the lock handle  46  is no longer secured to the cylinder  22 , and gravity causes the lock tube  26  to rotate clockwise. However, the upper first tube end portion  38  engages the cylinder  22  as the lock tube  26  is rotating clockwise, which prevents the lock tube  26  from moving into the locked position. Thus, the spring strut  14  continues to compress and the cylinder  22  is received within the lock tube  26 . The spring strut  14  compresses until the hood H is closed, as shown in  FIG. 6 . 
   While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the present disclosure.