Abstract:
A tow device is mounted between two structural members of a vehicle which share in absorbing a moment of force transmitted through the device when the vehicle is towed. One of the structural members is substantially normal to the axis about which the moment of force acts to provide resistance to structural deformation, while permitting the device to project below the vehicle body proper to prevent accidental impacting of the vehicle underbody on the road.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an automotive vehicle body construction and more specifically to a tow device thereof which features increased structural strength and which serves to protect the lowermost components of the vehicle with accidental impact against the road surface. 
     2. Description of the Prior Art 
     In a known arrangement, a hook or the like has been welded or otherwise fixedly secured to an essentially horizontal vehicle underpanel at a location above the lowermost level of the vehicle bottom. This arrangement has suffered from a number of drawbacks, such as impaired accessibility and susceptibility to buckling or other deformation upon the application of an excessive load when a cable or similar device is connected to the hook. 
     In an effort to overcome these problems it has been hitherto proposed to increase the thickness and strength of the panel to which the hook is attached and/or to add a reinforcing member to the existing panel to locally reinforce same against the aforementioned buckling. While these measures have to some extent solved the problem, they have inherently added undesirable weight and cost to the vehicle. 
     SUMMARY OF THE INVENTION 
     The present invention features a tow device disposed between and fixedly connected to two panels defining part of the vehicle structure. At least one of the panels has a wall section essentially perpendicular to the vehicle underpanel and parallel to the longitudinal axis thereof. The tow device is affixed to this wall section so that upon application of a large moment of force to the tow device, the buckling phenomenon exhibited by prior art constructions is resisted by the orientation of the wall section with respect to the axis about which the moment of force acts and by the distribution of the moment through two panels rather than through a single panel to an interconnected adjacent panel. The increased resistance to buckling under relatively large force moments permits the tow device to simultaneously perform a protective function by projecting below the lowermost portion of the vehicle body (such as the fuel tank and the exhaust pipe) to prevent impacting of the vehicle bottom on the road surface should the wheel or wheels enter pot holes or the like in the road. 
     Additional objects, advantages and novel features of the invention will be set forth in the description which follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features and advantages of the tow device according to the present invention will be more clearly appreciated from the following description taken in conjunction with the accompanying drawings in which like reference numerals designate corresponding elements, and in which 
     FIG. 1 is a view of the rear half of an automobile showing the disposition of a device according to the present invention as well as (in broken line) of the prior art arrangement; 
     FIG. 2 is a sectional view taken along section line A--A of FIG. 1; 
     FIG. 3 is a sectional view taken along section line B--B of FIG. 2; 
     FIG. 4 is a front elevation of a second embodiment of the present invention; 
     FIG. 5 is a sectional view taken along section line D--D of FIG. 4; 
     FIG. 6 is a sectional view taken along section line E--E of FIG. 4; 
     FIG. 7 is an exploded perspective view showing the second embodiment the present invention and a recess formed in the vertical panel in which the device is mounted; and 
     FIG. 8 is a sectional view of the arrangement shown in FIG. 7. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning now to the drawings and more specifically to FIGS. 1, 2 and 3, a first embodiment of the tow device of the present invention is illustrated. A vehicle 1 has a structural panel 2, which in this case defines the floor of the vehicle trunk. The structural panel 2 is reinforced by longitudinally extending structural members 4 and 5, which have substantially channel shaped cross sections. A fuel tank 6 is mounted between the structural members 4 and 5, and an exhaust pipe 7 is mounted to the vehicle adjacent the fuel tank. 
     The structural panel 2, defining the floor of the trunk (or floor panel as it will be referred to hereinafter), is formed with perpendicular wall sections 8 and 9, which mate with external body panels 10 and 11. The perpendicular wall section 9, as illustrated, is further formed with an essentially horizontal section 3 which mates with the external body panel 11 to define a spare tire well 12 or the like. As best shown in FIGS. 2 and 3, the first embodiment of the tow device 14 of the present invention is sandwiched between a downwardly depending flange 13 of the channel member 5, and the perpendicular wall section 9, and is fixedly connected to one or both by welding or the like. In the first embodiment, the tow device takes the form of a simple U-shaped bar, the ends of which are welded in an appropriately shaped recess 15 formed into either or both of said wall section 9 and said flange 13. In FIG. 3, the recess 15 is shown to be formed in the perpendicular wall section 9. 
     The second embodiment of the present invention is illustrated in FIGS. 4 to 8. This embodiment differs from the first in that the U-shaped bar 14, is initially fixed (by welding or the like) to a base plate or structural attachment member 16. The structural attachment member 16 is formed with a flat section 17 and a raised section 18. The raised section 18 is interposed between the ends of the U-shaped member 14 which are, in the illustrated embodiment, welded to both the raised and flat sections. 
     While the arrangement illustrated in FIGS. 4 to 6 could be easily attached to a flat surface of the perpendicular wall section 9, it is preferred to additionally form a recess 19 in the perpendicular wall section 9 for receiving the structural attachment member 19 therein. The attachment member 16 is formed with flanges 20 and 21 which respectively contact the inner top edge of the recess 19 and the bottom of the spare tire well 12. In the instance where the recess is not provided, it is possible to seat the the flange 20 against the inner surface of the longitudinally extending structural member 5. 
     Thus, in the second embodiment of the tow device, the U-shaped bar 14 is fixed initially to the base plate (structural attachment member) 16, and the combination is then fixed in the recess 19. In this manner, locating the tow device during production is facilitated, and outstanding structural rigidity results. A loading force on the U-shaped bar 14 acts essentially parallel to the vehicle&#39;s longitudinal axis, resulting in a force moment about an axis essentially normal thereto tending to rotate the bar and attachment member 16. Due to the construction of the attachment member 16 including the raised section 18 and the perpendicular wall section 9 including the recess 19, the structural integrity of the wall section is greatly increased, thereby preventing the wall section 9 and the structural member flange 13 from buckling even under extreme conditions of excessive loading forces. 
     Accordingly, due to its inherent resistance to deformation, the two device projects as illustrated in FIG. 1, below the lowermost level of the vehicle body (in contrast with the prior art arrangement 22 illustrated in broken lines in FIG. 1) to define a definite degree of protection of the vehicle components such as the fuel tank 6 and exhaust pipe 7, in the event the vehicle should bottom out on its suspension due to various road conditions. 
     Thus, with the disclosed embodiments of the present invention it will be appreciated that without the need for increasing the thickness and strength of material from which the members such as the structural member 5 are formed, and without the need for any additional reinforcement panels, the present invention provides sufficient structual strength and rigidity to permit the tow device to serve as both a tow device and a protective device. 
     Further, it will be appreciated that the present invention is not limited to the rear of the vehicle and can be applied to front of same with equal effect. 
     The foregoing description of the preferred embodiments of the invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.