Helmet holding bag

Abstract

The present invention is a backpack with an expandable compartment designed to store a helmet. The expandable compartment front surface of the outer compartment is made of a sheet of material larger than the dimensions of the expandable compartment, so the expandable compartment may expand when full. The backpack also includes a main compartment, and a rigid surface separating the expandable compartment and the main compartment, allowing the main compartment to maintain the same volume when the expandable compartment is full. The backpack also includes a secondary compartment designed to hold a laptop computer.

What is claimed is: 
     
         1 . A backpack comprising:
 an expandable compartment, comprising a first interior volume, a first front surface, a first back surface, a first bottom surface, a first top surface, a first side surface, and a second side surface, wherein the first front surface is coupled to each of the first side surface and the second side surface, each of the first side surface and second side surface is coupled to the first back surface, and wherein the first front surface, each of the first side surface and the second side surface, and the first back surface are all coupled to both the first top surface and the first bottom surface, and wherein the first front surface, the first back surface, the first side surface, the second side surface, the first top surface, and the first bottom surface all define a first interior volume, and wherein the first front surface comprises a first position, and a second position;   a main compartment, comprising a second interior volume, a second front surface, and a second back surface, a third side surface, and a fourth side surface, wherein the second front surface is coupled to each of the third side surface and the fourth side surface, each of the third side surface and the fourth side surface is coupled to the second back surface, and wherein the second front surface, the third side surface, the fourth side surface and the second back surface are all coupled to both a second top surface and a second bottom surface, and wherein the second front surface, the second back surface, the third side surface, the fourth side surface, the second top surface, and the second bottom surface all define the second interior volume; and   wherein the first front surface of the expandable compartment comprises a sheet of material, comprising a height and a width, wherein the height of the sheet of material is greater than the height of the expandable compartment, and the width of the sheet of material is greater than the width of the expandable compartment, such that when the front surface of the expandable compartment moves from a first position to a second position, the first interior volume of the expandable compartment increases, and the second interior volume of main compartment remains the same.   
     
     
         2 . The backpack of  claim 1 , wherein the sheet of material is elastic. 
     
     
         3 . The backpack of  claim 1 , wherein the first front surface further comprises an elastic sheet coupled to the sheet of material. 
     
     
         4 . The backpack of  claim 3 , wherein the elastic sheet comprises a height and a width, wherein the height of the elastic sheet is the same as the height of the expandable compartment, and wherein the width of the elastic sheet is the same as the width of the expandable compartment. 
     
     
         5 . The backpack of  claim 1 , wherein the first back surface of the expandable compartment, and the second front surface of the main compartment are one surface. 
     
     
         6 . The backpack of  claim 5 , wherein the one surface is rigid. 
     
     
         7 . The backpack of  claim 6 , wherein the third side surface, the fourth side surface, the second top surface, and the second bottom surface of the main compartment are all rigid. 
     
     
         8 . The backpack of  claim 6 , further comprising a third compartment designed to hold a laptop. 
     
     
         9 . The backpack of  claim 6 , wherein the third compartment comprises a third front surface and a third back surface, and wherein the third front surface of the third compartment and the second back surface of the secondary compartment are the same surface, and the third back surface of the third compartment is designed to rest on a user's back. 
     
     
         10 . A backpack comprising:
 an expandable compartment, comprising an first interior volume, a first front surface, a first back surface, a first bottom surface, a first top surface, a first side surface, and a second side surface, wherein the first front surface is coupled to each of the first side surface, and the second side surface, each of the first side surface, and the second side surface is coupled to the first back surface, and wherein the first front surface, the first side surface, the second side surface, and the first back surface are all coupled to both the first top surface and the first bottom surface, and wherein the first front surface, the first back surface, the first side surface, the second side surface, the top surface, and the bottom surface all define a first interior volume, and wherein the first front surface comprises a first position, and a second position;   a main compartment, comprising a second interior volume, a second front surface, and a second back surface, a third side surface, and a fourth side surface, wherein the front surface is coupled to each of the third side surface, and the fourth side surface, each of the third side surface and the fourth side surface is coupled to the second back surface, and wherein the second front surface, the third side surface, the fourth side surface and the second back surface are all coupled to both a second top surface and a second bottom surface, and wherein the second front surface, the second back surface, the third side surface, the fourth side surface, the second top surface, and the second bottom surface all define the second interior volume;   a third compartment designed to hold a laptop; and   wherein the first back surface of the expandable compartment and the second front surface of the main compartment are one surface, and the one surface is rigid, and the first front surface of the expandable compartment comprises a sheet of material, comprising a height and a width, wherein the height of the sheet of material is greater than the height of the expandable compartment, and the width of the sheet of material is greater than the width of the expandable compartment, such that when the front surface of the expandable compartment moves from a first position to a second position, the first interior volume of the expandable compartment increases, and the second interior volume of main compartment remains the same.   
     
     
         11 . The backpack of  claim 10 , wherein the third compartment comprises a third front surface and a third back surface, wherein the third front surface of the third compartment, and the second back surface of the main compartment are one surface, and the third back surface of the main compartment is configured to rest on a user's back. 
     
     
         12 . The backpack of  claim 11 , wherein the one surface comprises plastic or metal. 
     
     
         13 . The backpack of  claim 11 , wherein the third side surface, the fourth side surface, the second top surface, and the second bottom surface of the main compartment are all rigid. 
     
     
         14 . The backpack of  claim 13 , wherein the third side surface, the third side surface, the second top surface, and the second bottom surface of the main compartment comprises metal. 
     
     
         15 . The backpack of  claim 13 , wherein the third side surface, the fourth side surface, the second top surface, and the second bottom surface of the main compartment comprise plastic. 
     
     
         16 . The backpack of  claim 10 , further comprising at least one strap coupled to the second back surface of the main compartment. 
     
     
         17 . A backpack comprising:
 an expandable compartment, comprising a first interior volume, a first front surface, a first back surface, a first bottom surface, a first top surface, a first side surface, and a second side surface, wherein the front surface is coupled to each side surface, each side surface is coupled to the back surface, and wherein the front surface, each side surface, and the back surface are all coupled to both the top surface and the bottom surface, and wherein the front surface, the back surface, the two side surface, the top surface, and the bottom surface all define an interior volume, and wherein the front surface comprises a first position, and a second position;   a main compartment, comprising an interior volume, a front surface, and a back surface, two side surfaces, wherein the front surface is coupled to each side surface, each side surface is coupled to the back surface, and wherein the front surface, each side surface, and the back surface are all coupled to both the top surface and the bottom surface, and wherein the front surface, the back surface, the two side surface, the top surface, and the bottom surface all define an interior volume;   a third compartment designed to hold a laptop, comprising a front surface and a back surface, wherein the front surface of the third compartment and the back surface of the main compartment is one surface, and the back surface of the third compartment is configured to rest on a user's back;   at least one strap coupled to the back surface of the third compartment; and   wherein the back surface of the expandable compartment and the front surface of the main compartment is one surface, and the one surface comprises metal, and the front surface of the expandable compartment comprises a sheet of material, comprising a height and a width, wherein the height of the sheet of material is greater than the height of the expandable compartment, and the width of the sheet of material is greater than the width of the expandable compartment, such that when the front surface of the expandable compartment moves from the first position to the second position, the interior volume of the expandable compartment increases, and the interior volume of main compartment remains the same.