Patent Publication Number: US-6908108-B1

Title: Roll cage

Description:
BACKGROUND 
   Substantial interest has developed in the operation and competitive racing of radio controlled, gasoline and electric powered model automobiles and trucks of relatively sophisticated design. These model trucks and automobiles use small, high performance gasoline and engines and include transmissions, radio controlled power steering mechanisms and sophisticated suspension systems. The models typically are between two and three feet in length, with proportionate width, and generally have a plastic “body” cover mounted over the operating components on the chassis of the model. Typically, the plastic body, which provides the overall esthetic appearance, of the model is mounted at the front and rear onto shock absorber towers for the front and rear wheels. 
   Gasoline and electric powered radio controlled model automobiles and trucks of the general type described above are capable of being operated at relatively high speeds, on the order of 40 MPH, or more. In addition, by utilizing relatively large wheels (compared to the size of the overall chassis), the models are designed to be operated over relatively rough, rugged, rocky terrain, if desired. When the models are raced against one another, or when they are operated over rough terrain, they occasionally roll over. When this occurs, the plastic body cover undergoes considerable stress, and often the body cover is damaged. In addition, the common mounting of the body cover to the shock absorber towers may result in breaking of the towers in a rollover, since typically they also are made of plastic. If the body cover, which is a relatively weak, lightweight component, is crushed or broken away, the operating components of the model attached to the underlying chassis also may be subjected to damage by contact with the ground in the event of a rollover. 
   The United States patent to Fahrendorff U.S. Pat. No. 3,583,095 discloses a toy vehicle which has a roll bar attached to the frame, near the rear of the vehicle. A top for the vehicle has parts which extend through portions of the underlying vehicle with tabs at the front, and then is clipped onto the roll bar at the rear. The vehicle, however, is not a radio controlled model car or truck; and the roll bar simply serves as a connecting member for attaching clips on the underside of the top to securely hold the top on the body. As mentioned in this patent, the interconnection of the top with the roll bar is maintained with sufficient force to allow the toy to be picked up solely by its top in normal play by children. The roll bar essentially is in the form of an inverted U-shaped solid, cylindrical rod. 
   The United States patent to Harrod U.S. Pat. No. 5,718,454 discloses a child&#39;s ride-on vehicle, which has an open top and which has a tubular roll bar attached across the rear of the toy around the seat. 
   It is desirable to provide a roll cage for gasoline and electric powered, radio-controlled model automobiles and trucks which is simple to manufacture and install, and which provides rollover protection for components mounted on the chassis of the model. 
   SUMMARY OF THE INVENTION 
   It is an object of this invention to provide an improved roll cage for a model car or truck. 
   It is another object of this invention to provide an improved easy to assemble roll cage for a model car or truck. 
   It is an additional object of this invention to provide an improved roll cage made of flat stock for a model car or truck. 
   It is a further object of this invention to provide an improved flat stock metal roll cage for supporting the body and protecting the operating components of a model car or truck. 
   In accordance with a preferred embodiment of the invention, a roll cage for a model car or truck having an elongated chassis carrying the operating components of the model car or truck comprises at least one elongated roll cage member configured to substantially overlie the length of the chassis over operating components on the chassis. At least one generally inverted U-shaped roll cage member is configured to substantially overlie the width of the chassis, with the bight portion of the inverted U-shaped roll cage member located over operating components on the chassis. The elongated roll cage member and the inverted U-shaped roll cage member are interconnected at the bight portion of the U-shaped roll cage member; and the roll cage is attached to the chassis of the model car or truck. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a top front perspective view of a preferred embodiment of the invention mounted on a model car; 
       FIGS. 2 ,  3 ,  4  and  5  are side views of components of the embodiment shown in  FIG. 1 ; 
       FIG. 6  is a diagrammatic perspective view of the components of  FIGS. 2 ,  3 ,  4  and  5  illustrating the manner of assembly of these components; 
       FIG. 7  is a top perspective view of the fully assembled components of  FIG. 6 ; and 
       FIGS. 8 and 9  are side views of alternative components to the ones shown in  FIGS. 2 and 3 . 
   

   DETAILED DESCRIPTION 
   Reference now should be made to the drawing, in which the same reference numbers are used throughout the different figures to designate the same or similar components.  FIG. 1  is a top perspective view of a model car or truck chassis to which a preferred embodiment of the invention has been mounted or attached. The model car  20  of  FIG. 1  is diagrammatically illustrated; and the actual detailed physical interconnections of various parts of the model car which are not necessary for an understanding of the present invention are show only in diagrammatic form. 
   Basically, the model car  20  which is shown in  FIG. 1  is a radio-controlled (RC) gasoline or electric powered model car of a generally conventional design. The car  20  includes a chassis plate  22 , which either may be an original equipment chassis plate or one which is provided as a modification to the original model car kit. 
   As illustrated in  FIG. 1 , the chassis plate  22  has slightly upturned longitudinal edges  24  on each side of the plate  22 . Various operating components (not numbered) for the model car, including the gasoline engine, exhaust system, gasoline tank or battery, RC receiver, steering control, and other components, are mounted on top of the chassis  22 . Some of these components are represented in  FIG. 1  on the chassis  22 . These components operate in a standard manner to provide the operation of the car; and these components are not important for an understanding of the present invention directed to a roll cage. 
   To provide an orientation for the various parts, however, details of some of the car components ate diagrammatically illustrated in  FIG. 1 . The front and rear of the chassis  22  includes extensions  30  and  40  (extension  40  is shown partially broken away) for supporting combined shock absorber towers and bump-stop elements  28  and  38  on the front and rear ends of the chassis respectively. The manner in which these shock absorber towers  28  and  38  are connected to the chassis  22  is conventional; and the details are not illustrated in  FIG. 1 . 
   As diagrammatically illustrated in  FIG. 1 , independent suspension is provided for the two front wheels  32  and the two rear wheels  42 , which are shown as carried by front support members  26  and rear support members  46 , respectively. Again, it should be noted that these elements are only diagrammatically represented, and that in a typical assembly this independent suspension will involve automobile-like interconnections of pivoted wheels and axle assemblies, along with appropriate ball joints, steering tie rods and the like for the front wheels  32 , and transmission connections for the rear wheels  42  (and for a four wheel drive, the front wheels  32  as well). These details are not shown, since to do this would unnecessarily clutter the drawing with components that form no part of the present invention. The supports  26  and  46  are mounted through shock absorbers  34  in the front and  44  in the rear to the shock towers  28  and  38 , respectively, through spacers  36  (in the front) and  46  (in the rear) attached to the shock towers  28  and  38 , as diagrammatically illustrated in  FIG. 1 . 
   As shown in  FIG. 1 , a completed roll cage assembly extends over all of the components described above. This roll cage assembly includes two spaced-apart elongated roll cage members  50  and  60 , which extend generally parallel to one another longitudinally of the length of the chassis  22 , and overlie the operating components on the chassis  22  and the front and rear wheel assemblies as well. 
   These elongated longitudinally oriented roll cage members  50  and  60  are supported on a pair of generally inverted U-shaped transverse roll cage members  100  and  110 , which extend across the width of the chassis  22 , and which are spring-fit onto the upturned edges  24  on opposite sides of the chassis  22  through slots  106  and  108  on the member  100 , and slots  116  and  118  on the member  110 , as most clearly shown in  FIGS. 8 and 9 . 
   The elongated longitudinally oriented roll cage members  50  and  60  are spaced apart at their forward and remote ends by means of spacer bars  70 , six of which are illustrated in  FIG. 1 . Similar spacer bars also may be provided between the ends of the transverse roll cage members  100  and  110 , in a similar fashion; although such spacer bars have not been shown in  FIG. 1 , again to avoid cluttering of the drawing. 
   It should be noted that model cars and trucks of the type generally described above are provided with a molded plastic body or cover, which provides the esthetic appearance of the design of the car or truck. The underside of such a plastic body conforms with the upper surface of the roll cage members  50 , 60 , 100  and  110 ; so that firm support for this body (not shown) is provided throughout its length and width. Thus, in the event of a rollover, the plastic body is not crushed but is supported by the roll cage  50 , 60 , 100 , 110 . 
   Connection of the plastic body to the roll cage readily may be effected by providing openings through the body which correspond to projections  72 , 74  spaced apart on the elongated roll cage members  50  and  60  and similar projections near the lower ends of the transversely located inverted U-shaped roll cage members  100  and  110 . These projections are provided with holes through them to permit body clips or locking pins to be placed through the holes above the plastic body to removably hold it in place on the roll cage. 
   The roll cage, shown assembled on the model car or truck  20  of  FIG. 1 , employs the elongated roll cage members  50  and  60  shown in  FIGS. 4 and 5 , and the transverse members  100  and  110  shown in  FIGS. 8 and 9 . An alternative to the inverted U-shaped transverse roll cage members shown in  FIGS. 8 and 9  is illustrated in  FIGS. 2 and 3 . 
   As illustrated in  FIGS. 4 and 5 , the elongated or longitudinal roll cage members  50  and  60  are of substantially identical configuration, and are designed to be spaced apart by the spacer bars  70  in the manner shown in  FIG. 1 . These roll cage members include forward down turned ends  52  and  62 , respectively, with rear down turned ends  54  and  64 , respectively, (as shown most clearly in  FIGS. 4 and 5 ), the orientation of which is illustrated in  FIG. 1 . As mentioned above, the upper edges of the roll cage members  50  and  60  are designed to closely underlie the plastic body designed to be attached to the roll cage members  50  and  60 . Obviously, for different body designs the configuration of this surface of the members  50  and  60  can be varied to accommodate different shapes of plastic bodies to be attached to the roll cage members. 
   The upwardly extending projections  72  on the member  50  and  74  on the member  60  are designed to be extended through holes or apertures in a plastic body to allow cotter pins or body clips to be inserted through the holes in these members over the body, which is then held in tight engagement with the upper surface of the elongated members  50  and  60 . The lowermost ends  53  and  55  of the member  50  and  63  and  65  of the member  60  are configured to extend downwardly adjacent to or slightly above the members  26  and  46  illustrated in  FIG. 1 . In the embodiment shown in  FIG. 1 , there is no interconnection of the ends  53 , 63 , 55  and  65  with any part of the chassis; and these components simply extend over and protect the wheel mounts and shock towers of the model. 
   As shown in  FIGS. 8 and 9 , the inverted U-shaped transverse members  100  and  110  include downwardly extending legs  102  and  104  for the member  100 , and  112  and  114  for the member  110 . These legs extend downwardly from the bight of the inverted U-shaped transverse members. Each of these members terminates, as described previously, at the lower end of the legs in angled slots  106 / 108  for the member  110 , and  116 / 118  for the member  110 . Again as described previously, these slots engage the upturned edge  24  of the chassis  22  to clamp the members  100  and  110  firmly in place on the edge of the chassis  22 . 
   As is most clear from an examination of  FIGS. 1 ,  6  and  7 , all of the components forming the roll cage  50 , 60 , 100 , 110  (and in an alternative embodiment,  80  and  90 ) are made of flat stock, preferably of metal such as steel or aluminum. The assembly of the roll cage is effected without requiring any fasteners or welding or brazing, by means of alternating mating slots  56  and  58  on the member  50 ,  66  and  68  on the member  60 . These slots are designed to be engaged with corresponding slots on the members  100  and  110 , namely the slots  101 , 105  and  111  and  115 . 
   As shown in  FIGS. 2 and 3 , an alternative configuration of the members  100  and  110  is illustrated, which is identical to the members of  FIGS. 8 and 9  with the exception of the termination at the lower ends of these members. The inverted U-shaped roll cage members  80  and  90  shown in  FIGS. 2 and 3  include downwardly depending arms  82  and  84  for the member  80  and  92  and  94  for the member  90 . These arms extend downwardly from the bight of the U-shaped cross members and terminate in hook shaped terminations  86  and  88  for the member  80  and  96  and  98  for the member  90 . Also shown in  FIGS. 2 and 3  are projections  87 , 89 , 97  and  99 , which extend through the plastic car body, described above, to allow it to be clipped into place in conjunction with the projections  72  and  74  for the members  50  and  60 . 
   The roll cage assembly is effected without any fasteners, welding or brazing being necessary. As shown in  FIG. 6 , this is accomplished by slip-fitting mating slots  56 , 58 , 66 , 68  on the members  50  and  60  with slots  81 , 85  and  91 , 95  on the members  80  and  90  in the manner generally indicated in  FIG. 6 . The components are aligned as illustrated in  FIG. 6 ; and then the transverse U-shaped roll cage members  80  and  90  are rotated in the direction of the arrows shown in  FIG. 6  to inter-engage the upwardly facing slot  81  on the member  80  with the downwardly facing slot  56  on the member  50 , and the downwardly facing slot  85  on the member  80  with the upwardly facing slot  66  on the member  60 . Similarly, rotation of the transverse U-shaped member  90  is made to inter-engage the slots  95  and  58 , as shown in  FIG. 6 , and the slots  91  and  68  to form the completed roll cage assembly, as illustrated in  FIG. 7 . 
   It should be noted that the slots are formed substantially half way through the width dimensions of all of the various members  50 , 60 , 80  and  90  (and member  100  and  110 ) to provide the integrated friction-fit assembly shown in  FIG. 7 . When steel or aluminum parts are used for the material of the roll cage members, the tight fitting inter-engaged slots shown in  FIGS. 2 ,  3 ,  4 ,  5  and illustrated in the assembly drawing of  FIG. 7  cause a very rigid assembly to take place. When the spacer bars  70  described above in conjunction with  FIG. 1  are added, the assembly is quite strong. 
   With the assembled roll cage shown in  FIG. 7 , the downward projecting hook-like ends  86 , 88  and  96 , 98  may be extended through holes or apertures in the chassis  22  to then engage the edges of the chassis. Similarly, these hooks could be extended over the edge of a flat chassis  22  (not illustrated) by forcing outwardly, against spring tension, the lower ends of the members  80  and  90  to then allow them to snap back under spring tension and grip the chassis or an aperture in the edge of the chassis, depending upon how the roll cage is to be attached to such a chassis. 
     FIGS. 8 and 9 , illustrated in conjunction with  FIG. 1 , include transverse inverted U-shaped roll cage members which are similar to the members  80  and  90 , but which include a different configuration at the lower ends in the form of the slots  106  and  108  for the member  100 , and  116  and  118  for the member  110 . The slots are angled slightly upwardly from their open ends, as shown clearly in  FIGS. 8 and 9 , and allow the engagement of the slots with the angled upturned edge  24  of the chassis shown in  FIG. 1  to be effected by means of these members. 
   The interconnection of the configuration of the members  100  and  110  of  FIGS. 8 and 9  with the elongated roll cage members  50  and  60  is effected in the same manner illustrated in  FIG. 6  for the members  80  and  90 . In such a case, the upturned slot  101  on the member  100  engages the down facing slot  56  on the member  50 , and the downturned slot  105  engages the upward facing slot  66  on the member  60 . Similarly, the downward facing slot  111  engages the upward facing slot  58  on the member  50 ; and the upward facing slot  115  on the member  110  engages the downward facing slot  68  on the member  60 . The assembly then has the same appearance as that shown in  FIG. 7  incorporating the members  50 , 60 , 80  and  90 . The slots  106  and  108  on the legs  102  and  104  and the slots  116  and  118  on the legs  112  and  114  then are used to removably secure the roll cage to the chassis  22 . 
   Another alternative, which is not illustrated, for attaching the roll cage to the chassis  22  of the model is to provide the lower ends of the legs of the U-shaped transverse roll cage members, such as  80 , 90 , 100  and  110 , with a projection to extend through a hole or aperture in the chassis plate  22  for engagement with a spring clip or cotter pin located beneath the chassis. This type of interconnection, however, requires additional parts; whereas the configurations shown in  FIGS. 2 ,  3 ,  8  and  9  are held in place by the spring action of the arms of the transverse roll cage members  80 , 90 , 100  and  110 . Consequently, the embodiments shown in  FIGS. 2 ,  3 ,  8  and  9  are preferable; although a roll cage which employs additional fasteners or connecting members clearly can be used as well as the ones which have been illustrated and described above. 
   The foregoing description of the preferred embodiment of the invention is to be considered illustrative and not as limiting. Various changes and modifications will occur to those skilled in the art for performing substantially the same function, in substantially the same way, to achieve substantially the same result, without departing from the true scope of the invention as defined in the appended claims.