Snowmobile chassis

Abstract

Vehicle chassis with effective load sharing joints and reinforcing structure. The chassis of the invention use self piercing rivets and other fabrication techniques to improve their structural and performance characteristics. These improvements result from, among other things, effective load distribution through high-shear resistant fasteners and strengthening of structural elements with reinforcing layers.

1 . A system for constructing a vehicle comprising: 
 a. a first sheet of material;    b. a second sheet of material;    c. a third sheet of material of a different composition than at least one of the first sheet of material or second sheet of material; and    d. a self piercing rivet, the self piercing rivet attaching the first sheet of material and the second sheet of material to the third sheet of material to form a joint that allows load sharing or structural reinforcement of at least one of the first sheet of material or the second sheet of material by the third sheet of material.    
   
   
       2 . The system of  claim 1 , further comprising a fourth sheet of material of a different composition than the third sheet of material, wherein the fourth is attached to the first, second, and third sheets of material by the self piercing rivet.  
   
   
       3 . The system of  claim 1 , further comprising a fourth sheet of material of the same composition than the third sheet of material, wherein the fourth is attached to the first, second, and third sheets of material by the self piercing rivet.  
   
   
       4 . The system of  claim 1 , further comprising a second self piercing rivet that attaches the first sheet of material and the second sheet of material to the third sheet of material to reinforce the joint.  
   
   
       5 . A snowmobile comprising: 
 a. a chassis including at least two sheets of chassis material;    b. an engine supported by the chassis;    c. at least one ski supported by the chassis;    d. a steering column operatively connected to the at least one ski for steering the snowmobile;    e. an endless track supported by the chassis and being operatively connected to the engine;    f. a third sheet of material of a different composition than at least one of the sheets of chassis material; and    g. a self piercing rivet that attaches the at least two sheets of chassis material to the third sheet of material.    
   
   
       6 . The snowmobile of  claim 5 , wherein the two sheets of chassis material and the third sheet of material are formed at an angle greater than 45 degrees proximate to the rivet.  
   
   
       7 . The snowmobile of  claim 5 , wherein the third sheet of material is formed at an angle greater than 45 degrees to reinforce the chassis in two directions.  
   
   
       8 . The snowmobile of  claim 5 , wherein the third sheet of material reinforces the at least two sheets of chassis material.  
   
   
       9 . A snowmobile chassis, comprising: 
 a. first and second sheets of chassis material being formed of aluminum;    b. a third sheet of chassis material being formed to reinforce the first and second chassis sheets and of a material other than aluminum;    c. a self-piercing rivet joining together the first, second, and third sheets of material to allow load sharing and structural reinforcement of the first and second sheets of chassis material.    
   
   
       10 . The snowmobile chassis of  claim 9 , wherein the sheets of chassis material are formed at an angle greater than 45 degrees that provides reinforcement in two directions.  
   
   
       11 . A snowmobile chassis, comprising: 
 a. a suspension element;    b. a mount for attaching the suspension element to a chassis;    c. a chassis with at least two layers of overlapping chassis material and a longitudinal chassis axis    d. a self piercing rivet that attaches the mount to the chassis and fastens together the at least two layers of chassis material.    
   
   
       12 . The snowmobile chassis of  claim 11 , wherein the suspension element is oriented at a skew angle to the chassis axis.  
   
   
       13 . The snowmobile chassis of  claim 12 , further comprising a chassis element oriented generally transverse to the chassis, wherein the self piercing rivet allows a load from the suspension element to be redirected to the generally transverse chassis element.  
   
   
       14 . The snowmobile chassis of  claim 12 , further comprising a chassis element oriented generally parallel to the axis of chassis, wherein the self piercing rivet allows a load from the suspension element to be redirected to the parallel chassis element.  
   
   
       15 . The snowmobile chassis of  claim 12 , further comprising a chassis element oriented at a skew angle to the longitudinal axis of the chassis, wherein the self piercing rivet allows a load from the suspension element to be redirected to the skew chassis element.  
   
   
       16 . A snowmobile chassis, comprising: 
 a. a chassis comprising at least one layer of chassis material;    b. a heat exchanger constructed of at least two layers of material;    c. a self piercing rivet that attaches the heat exchanger to the chassis by fastening the heat exchanger to the at least one layer of chassis material.    
   
   
       17 . The snowmobile chassis of  claim 16 , wherein the heat exchanger is constructed of at least three layers of material.  
   
   
       18 . A system for attaching a tube to a chassis, comprising: 
 a. a tube having opposing, parallel sides, wherein a portion of the tube is compressed so that the sides of the tube are adjacent to each other;    b. a chassis comprising at least one sheet of material;    c. a self piercing rivet that attaches the sheet of material to the tube at the compressed portion of the tube by fastening the adjacent sides of the tube to the sheet of material.    
   
   
       19 . A method of constructing a snowmobile chassis, comprising: 
 a. fabricating a first chassis element formed of a sheet of material;    b. fabricating a second chassis element formed of a sheet of material;    c. layering the first chassis element, second chassis element, and a reinforcing sheet of material of a different composition than at least one of the chassis elements and configured to reinforce at least one of the chassis elements; and    d. fastening the two chassis elements and the reinforcing sheet of material together via a self-piercing rivet to form a joint, the joint allowing load sharing and structural reinforcement of at least one of the chassis elements.    
   
   
       20 . The method of  claim 19 , wherein the reinforcing sheet stiffens at least one of the chassis elements.  
   
   
       21 . The method of  claim 19 , further comprising the step of layering a second reinforcing sheet of material and riveting the two sheets of reinforcing material and the two chassis elements together via a self piercing rivet to form a joint.  
   
   
       22 . The method of  claim 19 , wherein the layering of the first chassis element, second chassis element, and the reinforcing sheet of material results in a joint wherein the first chassis element, second chassis element, and reinforcing sheet of material are coextensive in the proximity of the joint.