Abstract:
A pressure contained car cannon for the launching and/or flipping of vehicles, or other large-scale props, for use in motion picture action sequences. The device consists of a car canon having a barrel, a cannon foot and a piston. By way of pneumatic pressure, force is achieved by transferring energy from the piston to the cannon foot, resulting in a push force which expels the cannon foot from the cannon barrel, launching the vehicle on its desired trajectory while keeping most all vapor and smoke contained within the barrel itself.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional application Ser. No. 62/174,112 filed Jun. 11, 2015, the disclosure(s) of which is hereby incorporated in its entirety by reference herein. 
    
    
     TECHNICAL FIELD 
     This invention relates to the process of filming cinematic sequences wherein live action vehicles or other large-scale props, are forcibly overturned for the camera. 
     BACKGROUND 
     These stunts often require the demonstration of large props, such as cars, SUV&#39;s, other vehicles, or other large scale props, traveling at high speeds, traveling through the air and flipping over. 
     Techniques for achieving cinematic special effects such as overturning a vehicle have been limited over the years. For instance, the most widely used method for inverting a vehicle, known as the black powder method, dates back to the early days of movie making. Its primitive technique can achieve positive results, however, it also carries several variables relating to both safety and effectiveness. 
     The black powder method involves attaching a cannon to the object or vehicle being overturned, placing a certain amount of black powder inside the cannon, and finally inserting a wooden or metal rod into the cannon. Once ignited, the powder emits a small explosion inside the cannon. The force created by this explosion expels the rod out of the cannon into the ground, and the resulting push force from the rod flips or overturns the vehicle. 
     Depending on the desired course of the vehicle and height of the flip, the amount of powder needed to accomplish the effect fluctuates; however, there is no definitive equation in which to determine the exact amount of force that will be generated from the amount of black powder used. Methods are indecisive at best, as it has remained over the years mostly a guessing game. These variables pose several threats to the overall success of the effect, including a significant safety risk to the crew, but especially to the stunt driver. 
     Another significant component in the black powder method is the use of wooden posts as the rod. Once detonated, the rod is expelled from the cannon shaft with unpredictable force. This is generally known as “the spit wad effect”. It is this force that ultimately launches the vehicle, however its unpredictable nature imposes a real safety threat for both crew and drivers. It is impossible to predict the course of the rod once it is ejected from the cannon shaft, and its resulting impact with the ground will often times cause a wooden rod to shatter, creating dangerous splinters which can injure those nearby. 
     Furthermore, the explosion itself causes an excessive amount of smoke and other fumes which manifest into a large cloud that trails the vehicle. It is then necessary to remove this cloud of smoke in post-production with the use of a computer, leaving a costly burden for the production. 
     No system currently exists which creates the desired effect of overturning a vehicle, or similarly large object, while not only maintaining a safe environment on set, but also with foreseeable accuracy. 
     SUMMARY OF THE INVENTION 
     The invention comprises a device created for the flipping or overturning of vehicles, or other large props, both stationary and in motion, for use in motion picture action sequences. The pressure contained car cannon of this invention consists of three major components, the cannon barrel, the cannon foot, and the piston. By way of pneumatic pressure, force is achieved by the transferring of energy from the piston to the cannon foot. The resulting push force expels the foot from the cannon barrel, thus launching the vehicle on its desired trajectory, while still keeping all vapor and smoke contained within the barrel itself. 
     The pressure contained car cannon is a self-contained system. It uses compressed gasses such as compressed air or other gasses, preferably nitrogen, as the source of its power, which is not only an effective propellant, but also allows the system to be pre-charged with accuracy up to +/−1 psi. The ability to pre-charge the compressed air or nitrogen allows an operator to know the exact amount of push force the cannon foot will inflict against the road, based on the psi charged in gas tanks prior to the effect. 
     The system also allows for operators to control the speed at which the air or nitrogen enters the cannon during implementation by use of a high pressure ball valve, thus adjusting the height and speed of the effect with great accuracy. For example, decreasing the speed of entry of the gas into the cannon will produce a slower car roll, whereas increasing the speed of gas entry can result in a car flip of extreme altitudes. 
     Furthermore, the resulting shock impact from detonation is greatly reduced by the use of compressed air or nitrogen. When using a black powder cannon, it may take less than 1/30 of a second to detonate, creating potential harm to drivers based on the resulting G force. In some cases drivers were even known for blacking out during detonation. However, the pressure controlled car cannons take more than ½ of a second to propel, significantly reducing the G force impact placed on the driver and creating a much safer environment overall. 
     Because the system is self-contained, no pressure or gas is lost during implementation. This gives the operators the added benefit of being able to analyze the effect after it has been completed. 
     This system also eliminates what is known as “the spit wad effect”, meaning the foot is not expelled with excessive velocity from the cannon. By leaving the piston inside the cannon barrel, the cannon foot itself does not turn into a projectile. The nitrogen or compressed air is kept behind the piston, by seals behind the piston, and never makes contact with the cannon foot, giving it significantly less energy once the piston has stopped moving and creating a much safer environment for crew members. 
     The piston also acts as a barrier for any gas or vapor that may be a by-product of the effect, thus eliminating the contrail previously produced during this effect and its need to be removed in post-production. 
     Every component within the pressure contained car cannon can be pre-checked and certified prior to implementation. Moreover, the entire system is entirely reusable, making it a very cost effective device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view drawing of a vehicle containing a pressure contained car cannon of this invention; 
         FIG. 2  is a front view of the vehicle with the cannon foot expelled; 
         FIG. 3  is a front view of the vehicle launched into the air; 
         FIG. 4  is a front view of the vehicle about to land on its top. 
         FIG. 5  is a perspective view of the pressure contained car cannon; 
         FIG. 6  is an exploded view of the pressure contained car cannon; 
         FIG. 7  is a perspective view of the vehicle with a portion of the top of the vehicle removed; 
         FIG. 8  is a perspective view of the valve assembly; and 
         FIG. 9  is an exploded view of the valve assembly. 
     
    
    
     DETAILED DESCRIPTION 
     The drawings referring to  FIGS. 1-9  illustrate the details of the invention. 
       FIGS. 1-4  show the front of a vehicle  10  sitting on the ground and containing the pressure contained car cannon  12 , comprising a piston  14 , a barrel  16  and a canon foot  18 . Car cannon  12  is located inside of the vehicle and  FIGS. 1-4  show an opening in the front of vehicle  10  in order to see car cannon  12  in the American passenger seat area. Cannon foot  18  comprises a rod  20  and a foot  22 . 
     The gas to be used for the effect or stunt, such as air or nitrogen, is contained in one or more gas tanks, which are placed into vehicle  10  where they cannot be seen. The gas tanks are shown in  FIG. 7 . The location of the gas tanks will vary depending upon the specific needs and/or dimensions of the vehicle being used. The tanks can be modified to fit in any location in the vehicle, such as the trunk, a passenger seat, rear seat, or if necessary a seat can be removed to make space for the tanks and/or car cannon  12 . Air, nitrogen and other gasses may be used to activate the car cannon. Nitrogen is preferred and safer to compress, because it contains no oxygen. 
     Referring to  FIG. 7 , once a location for the high pressure gas tanks  81  has been determined, shown in the rear area, a high pressure tank plate  83  having clamps  82  is securely fastened, such as welding, into the location and tanks  81  are securely held by clamps  82 . Also a valve mounting plate  60  is also securely fastened, such as welding, into a location in the vehicle. Valve mounting plate  60  contains the valve system  80 , shown in  FIGS. 8 and 9  in detail. 
     Referring to  FIGS. 8 and 9 , a 12-volt battery is used by the driver to activate a low pressure air control valve  66  which actuates a linear air cylinder. Low pressure air fitting  67  connects air lines to various components. Air line  68  is flexible tubing for connecting low pressure components. High pressure air fitting (t-valve)  69  connects high pressure air lines (not shown here) to high pressure ball valve  65 . High pressure ball valve  65  provides high pressure for actuating cannon  12 . 
     Ball valve linkage arm  70  converts linear motion from linear air cylinder  66  to rotational motion to open high pressure valve  65 . Control valve  66  opens and allows gas from low pressure compressed air tanks  61  to travel into linear air cylinders  62 . These air cylinders  62  then open high pressure ball valve  65  that allow gas from the high pressure compressed air tanks  81  to flow into cannon  12 . High pressure lines  85  are attached to the top plate  33  of cannon  12  by flange mount fittings and the high pressure gas is released via the air actuated high pressure ball valve  65 . The gas pressure used may be from 200 psi to 3000 psi as needed for the effect or stunt. Bottom plate  35  of cannon  12  has a center hole to receive rod  20 . 
     The amount of gas and gas pressure sent to cannon barrel  16  for the stunt, is pre-determined by a special effects operator. The detonation of the high gas pressure to car cannon  12  is activated by the stunt driver who has a button or switch to activate a 12-volt battery. The stunt driver activates the gas detonation because the driver has to determine that all elements, such as speed and location, are in proper position. Detonation is accomplished by releasing the high pressure gas to power piston  14 , strongly pushing rod  20  down and foot  22  down out of barrel  16 . Power piston  14  remains in barrel  16 . 
     Car cannon  12  can be attached anywhere in a vehicle. Placement is based on the desired trajectory of the vehicle. For instance, if cannon  12  is placed in the rear of a vehicle, when detonated, it will cause the vehicle to flip forwards, back end leading up. If placed in the front of a vehicle, when detonated, the vehicle will flip backwards, front end leading up. If placed on either side of the vehicle, the vehicle will flip sideways to right or left side of the vehicle. Cannon  12  is attached to the inside of the vehicle  12 . It is welded to the existing vehicle chassis or roll cage. Steel roll cages are standard in most stunt vehicles. 
       FIG. 2  shows vehicle  10  leaving the ground and beginning to flip, after piston  14  transfers energy, by the high pressure compressed gas, such as nitrogen or air, as a propellant, from the piston  14  to the cannon foot  22 , which has been expelled from barrel  16  and is hitting the ground and beginning to flip vehicle  10 . Rod  20  has foot  22  at the bottom end of rod  20 . Foot  22 , being attached to rod  20  by steel bolts, is inserted into barrel  16  and rod  20  makes contact against the bottom of piston  14  but is not attached to it. The bottom of rod  20  is attached to circular foot  22 , by steel bolts  32 . Foot  22  is held in place at its base with a small piece of bailing wire (not shown). The wire attaches under the base of foot  22  and connects to the base plate  35  of the cannon  12 . Upon detonation the wire naturally snaps and is discarded, it does not affect the car flip nor the expulsion of foot  22  from cannon  12 . It is just strong enough to hold foot  22  in place long enough to be detonated. 
       FIG. 3  shows vehicle  10  forced into the air with cannon foot  22  falling away from vehicle  10  and falling to the ground, while any remaining gas is left in barrel  16  behind piston  14  which remains in the bottom of barrel  16 . 
       FIG. 4  shows vehicle  10  about to land on its top with cannon foot  22  lying on the ground and the remaining gas in cannon barrel  16  behind piston  14 . 
       FIG. 5  is a perspective view of the closed pressure contained car cannon  12 , showing cannon barrel  16  and cannon foot  22  attached to rod  20  by bolts  32  and the top flange  33  and bottom flange  35 . Multiple holes  34  are used with wires or bolts to attach car cannon  12  to a vehicle. 
       FIG. 6  shows the various parts of car cannon  12 . The chart below itemizes each numbered part of the car cannon, their part description and their part function. 
     
       
         
               
               
               
             
           
               
                   
               
               
                 PART NO. 
                 PART DESCRIPTION 
                 PART FUNCTION 
               
               
                   
               
             
             
               
                 16 
                 BARREL - WELDED ASSEMBLY 
                 ACTS AS CYLINDER BORE. HOLDS IN AIR, 
               
               
                   
                   
                 ALLOWS PISTON TO TRAVEL THROUGH. 
               
               
                 20/22 
                 CANNON FOOT 
                 ELEMENT WHICH COMES IN CONTACT WITH 
               
               
                   
                   
                 THE GROUND. 
               
               
                 14 
                 PISTON 
                 TRANSFERS ENERGY TO CANNON FOOT. 
               
               
                   
                   
                 PREVENTS GASSES FROM ESCAPING BARREL 
               
               
                   
                   
                 POST DETONATION. 
               
               
                 51 
                 INLET STEEL BULKHEAD 
                 PORT OF ENTRY FOR COMPRESSED GASSES. 
               
               
                 50 
                 ALUMINUM GASKET PLATE 
                 ACTS AS A BARRIER OR SEAL WHICH 
               
               
                   
                   
                 PREVENTS GASSES, FROM ESCAPING THE 
               
               
                   
                   
                 BARREL. 
               
               
                 42 
                 ROD STEEL RING 
                 STOPS PISTON/PREVENTS PISTON FROM 
               
               
                   
                   
                 ESCAPING THE BARREL WHEN IT HITS THE 
               
               
                   
                   
                 END OF IT&#39;S STROKE. 
               
               
                 44 
                 ROD DELRIN RING 
                 ACTS AS SHOCK ABSORBER FOR PISTON 
               
               
                 43 
                 ROD RUBBER SEAL 
                 ACTS AS SHOCK ABSORBER FOR PISTON 
               
               
                 53 
                 ¾″-10 × 3″ GRADE 8 
                 SECURES THE INLET STEEL BULKHEAD 
               
               
                   
                 HEX BOLT 
               
               
                 40 
                 ¾″-10 × 4″ GRADE 8 
                 SECURES VARIOUS COMPONENTS. 
               
               
                   
                 HEX BOLT 
               
               
                 56 
                 ⅜″-16 × 1-¼″ GRADE 8 
                 SECURES HOSE FITTINGS WHICH ATTACH 
               
               
                   
                 HEX BOLT 
                 TO GAS LINES AND GAS TANKS. 
               
               
                 49 
                 ¾″ FLAT WASHER 
                 HELPS TO SPREAD BOLT LOAD, ALLOWS 
               
               
                   
                   
                 FOR MORE SECURITY. 
               
               
                 47 
                 ¾″-10 GRADE 8 HEX NUT 
                 SECURES BOLTS. 
               
               
                 54 
                 SPLIT FLANGE 
                 ACTS AS CLAMP WHICH HOLDS GAS 
               
               
                   
                   
                 FITTINGS IN PLACE. 
               
               
                 55 
                 318″ SPLIT LOCK WASHERS 
                 PREVENTS BOLTS FROM LOOSENING. 
               
               
                   
               
             
          
         
       
     
       FIG. 7  shows vehicle  10  with part of its top removed in order to see car cannon  12  and gas tanks  81 . The high pressure gas tanks  81  are shown in the rear area, a high pressure tank plate  83  having clamps  82  is securely fastened, such as welding, into the vehicle and tanks  81  are securely held by clamps  82 . Also a valve mounting plate  60  is also securely fastened, such as welding, into a location in the vehicle. Valve mounting plate  60  contains valve system  80 , shown in  FIGS. 8 and 9  in detail. 
       FIGS. 8 and 9  show the various parts of the valve assembly  80 . The chart below itemizes each numbered part, their description and their part function. A description of the valve operation has been described in detail above. 
     
       
         
               
               
               
             
           
               
                   
               
               
                 No. 
                 PART 
                 DESCRIPTION 
               
               
                   
               
             
             
               
                 60 
                 Valve Mounting Plate 
                 Provides a rigid base for all of the components in 
               
               
                   
                   
                 the Valve Assembly 
               
               
                 61 
                 Low Pressure Compressed 
                 Provides low pressure to Low Pressure Air 
               
               
                   
                 Air Tank 
                 Control Valve 
               
               
                 62 
                 Linear Air Cylinder 
                 Opens High Pressure Ball Valve 
               
               
                 63 
                 Cylinder Rod Clevis 
                 Connects rod of Linear Cylinder to Ball 
               
               
                   
                   
                 Valve Linkage Arm 
               
               
                 64 
                 Air Tank Clamp 
                 Fastens Low Pressure Air Tank to Mounting Plate 
               
               
                 65 
                 High Pressure Ball Valve 
                 Provides high pressure for actuating Cannon 
               
               
                 66 
                 Low Pressure Air Control Valve 
                 Actuates Linear air Cylinder when 12VDC is applied 
               
               
                 67 
                 Low Pressure Air Fitting (90°) 
                 Connects Air Lines to various components 
               
               
                 68 
                 Air Line 
                 Flexible tubing for connecting low pressure 
               
               
                   
                   
                 components 
               
               
                 69 
                 High Pressure air Fitting 
                 Connects High Pressure Air Lines (not shown 
               
               
                   
                   
                 here) to High Pressure Ball Valve 
               
               
                 70 
                 Ball Valve Linkage Arm 
                 Converts linear motion from Linear Air Cylinder to 
               
               
                   
                   
                 rotational motion to open High Pressure Ball Valve 
               
               
                 71 
                 Low Pressure Air Control Valve 
                 Fastens Low Pressure Air Control Valve to Air 
               
               
                   
                 Mount 
                 Tank Clamp 
               
               
                 72 
                 Linear Air Cylinder Pivot Plate 
                 Fastens Linear air Cylinder to Valve Mounting Plate 
               
               
                   
                   
                 and allows for slight rotation of Linear Air Cylinder 
               
               
                 73 
                 Low Pressure Air Fitting 
                 Connects Air Lines to various components 
               
               
                 74 
                 Pressure Gauge 
                 Allows for monitoring of pressure inside 
               
               
                   
                   
                 Low Pressure Compressed Air Tanks 
               
               
                 75 
                 Low Pressure Air Fitting 
                 Connects Air Lines to various components 
               
               
                   
                 (Reducer) 
               
               
                   
               
             
          
         
       
     
     This system for special effects prevents the escaping of gas/vapor and is also safer than other used systems. That is because the cannon foot is not ejected with excessive velocity from the cannon barrel. Other known systems continue exerting force on the ejected object, even after the vehicle has been flipped/launched. This can cause the ejected object to become a dangerous projectile and pose potential threats to crew members. This car cannon system prevents that by restricting the left over force in the barrel with the piston, so that the force is securely contained inside the cannon barrel. 
     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.