Patent Publication Number: US-2007116552-A1

Title: Pressurized gas transportation system

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates to the delivery and transportation of fuels in small containers, and in particular to methods and apparatus for making such delivery and transportation efficient and less costly.  
      The pressurized gas business is a competitive nationwide industry. The pressurized gas business requires the transportation of a large number of pressurized gas cylinders. These cylinders are filled with gas before delivery to customer sites. After the gas is consumed, the empty cylinders are picked up and delivered to the gas refueling station. These empty cylinders are refilled and delivered back to customer sites. This process requires repeated loading and unloading of filled and empty gas cylinders. Since the process requires repeated cylinder loading and unloading, the process is labor intensive and expensive. Therefore, the industry is constantly examining new ways to better transport the large numbers of pressurized gas cylinders needed by its customers.  
      palletized trucking system is one conventional approach for transporting the large numbers of pressurized gas cylinders needed in the industry, e.g., in Stavlo, U.S. Pat. No. 4,542,774. This conventional palletized trucking system allows a pallet holding a plurality of gas cylinders to be loaded and unloaded from the vehicle using a forklift, as opposed to loading and unloading individual gas cylinders. This conventional palletized trucking system reduced the number of times an operator was required to handle each individual cylinder, which in turn helped reduce the occurrence of operator injuries compared to earlier cylinder handling approaches.  
      However, such palletized trucking systems are not completely satisfactory. First, each of the cylinders still had to be individually loaded and unloaded from the pallet during the delivery cycle. In this conventional palletized trucking system, the cylinders are removed from the pallet for refueling. This refueling process requires handling each cylinder twice, once when the cylinder is removed from the pallet to recharge the cylinder, and again when it is returned to the pallet fully charged for delivery to a customer. There have been attempts to remedy this disadvantage that have met with varying degrees of success, e.g., in Princiotta, U.S. Pats. Nos. 5,709,252 and 5,954,099. However, improvements to the conventional approach are desirable.  
      Second, the weight and size of the pallets required that the pallets be loaded and unloaded from the delivery vehicle using a forklift or other mechanized equipment. The need to have such equipment available for loading and unloading may result in increased capital cost for gas cylinder providers and also increased fuel usage.  
      Third, this conventional palletized approach required that a delivery driver had to load and unload individual cylinders at customer sites. This may result in increased delivery times as the delivery driver was required to physically carry and place each cylinder at the desired customer location.  
      Fourth, the amount of physical handling of the cylinder often resulted in an increased rate of injuries occurring. In the conventional palletized trucking system, each cylinder is stored in an embedded position at a zero or negative angle to the horizontal plane. A cross bar may be positioned across the cylinders to lock the cylinders in place on the pallet. To remove a cylinder from a pallet, the cylinder may be manually lifted to clear the cross bar. Whether the cylinder is being lifted for delivery or recharging, such a movement may result in injury to an operator.  
      Improvements to the conventional approaches for handling and transporting pressurized gas cylinders for delivery to customers and for other purposes are desirable.  
     SUMMARY  
      The present invention relates generally to the transportation and handling of pressurized gas cylinders. More specifically, the present invention relates to a method of handling and delivering gas cylinders where the cylinders do not need to be removed from a cylinder holding cage during the charging with a desired gas and transportation of the cylinders to a delivery location. Cylinders are only removed from the cylinder holding cage upon transportation of the cage to a delivery location.  
      The present invention further relates to a cylinder holding cage for gas cylinders. The cage includes shelves for storing gas cylinders in a generally horizontal position and a base frame within which are formed receptacles for receiving a lifting device.  
      The present invention further relates to a hand truck for moving single gas cylinders. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, the invention, its mode of construction, assembly and its operation, and many of its advantages should be readily understood and appreciated.  
       FIG. 1  is a side view of a cylinder holding cage transportation system according to the present invention.  
       FIG. 2  is an enlarged perspective view of the cylinder holding cage transportation system of  FIG. 1 .  
       FIG. 3  is a front view of a cylinder holding cage according to the present invention included in the cylinder holding cage transportation system of  FIG. 1 .  
       FIG. 4  is a front perspective view of the cylinder holding cage of  FIG. 3 , and a hand truck for moving the holding cage.  
       FIG. 5  is a front view of the cylinder holding cage of  FIG. 3 .  
       FIG. 6  is a front view of the cylinder holding cage of  FIG. 3 , with the cylinders removed from the holding cage.  
       FIG. 7  is a side view of an operator refueling cylinders within the cylinder holding cage transportation system of  FIG. 1 .  
       FIG. 8  is a perspective view of a single cylinder hand truck according to the present invention, positioned to remove a cylinder from the cylinder holding cage.  
       FIG. 9  is a perspective view of an alternative embodiment of a single cylinder hand truck according to the present invention with an electrical lift, the hand truck positioned to remove a cylinder from the cylinder holding cage.  
       FIG. 10  is a side perspective view of a single cylinder hand truck of  FIG. 8 , positioned to receive a cylinder from the cylinder holding cage.  
       FIG. 11  is a side perspective view of the hand truck of  FIG. 10 , with a cylinder from the cylinder holding cage positioned on the hand truck.  
       FIG. 12  is a side view of the cylinder holding cage of  FIG. 3 , showing a closer view of the shelves.  
    
    
     DETAILED DESCRIPTION  
      Before the present methods are described, it is understood that this invention is not limited to the particular methodology or apparatuses described, as these may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention which will be limited only by the appended claims.  
      It must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural reference unless the context clearly dictates otherwise. Thus, for example, reference to “a door” includes a plurality of such door, and equivalents thereof known to those skilled in the art, and so forth.  
      Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described.  
      The practice of the present invention will employ, unless otherwise indicated, conventional techniques of mechanical and electrical engineering, which are within the skill of the art.  
      Referring to  FIG. 1 , a cylinder holding cage transportation system  12  includes transportation equipment, such as truck  14  with storage compartments  16  that may house a cylinder holding cage  10 . Suitable transportation equipment may include but is not limited to a truck, railcar, plane, car or ship. Storage compartments  16  include storage compartment access doors  18 . Truck  14  may include a lifting device, such as a fork lift  20  that may be stored externally. Suitable lifting devices include but is not limited to a forklift, hand truck, crane, conveyor, or pulley system.  
      As illustrated in  FIG. 2 , truck  14  includes storage compartments  16  that house the cylinder holding cage  10 . Cylinder holding cage  10  may be loaded with one or more gas cylinders  22 . Cylinder holding cage  10  may include lift receptacles  24 . Lift receptacles  24  may include but is not limited a hand truck cut out  26 . Cylinder holding cage  10  may be unloaded from the storage compartment  16  by forklift  20  or a hand truck (not shown).  
      Referring to  FIG. 3 , cylinder holding cage  10  includes a frame  27  which includes a support base frame  28  connected to sidewalls  30 , a front face  32 , a back face  34  and a bottom face  36 . The sidewalls  30 , front face  32  and back face  34  are connected to a top face  38 . It is preferable that the combination of sidewalls  30 , front face  32 , back face  34  and top face  38  will cooperate to define a rigid structure for frame  27  of cylinder holding cage  10 . A plurality of shelves  40  extend between sidewalls  30 . Cylinders  22  are stored on shelves  40 . If needed, support bars  42  may be used to provide increased bracing between adjacent shelves  40  and also from shelves  40  to base frame  28  and top face  38  to increase the load capacity of the shelves  40 .  
      In the illustrated example of  FIG. 3 , the shelves  40  include channel bars  44 . Channel bars  44  have a positive incline, meaning that they define a generally downward angled slope from adjacent front face  32  toward back face  34 . The positive incline may also be measured moving from back face  34  towards front face  32  with the end measuring point being at an apex  46  of a curve defined by at least one of the channel bars  44 . Front face  32  defines an access end for receiving cylinders  22  within cage  10 .  
      Referring now also to  FIG. 12 , channel bars  44  include a front end  43  and a back end  45 . Apex  46  may be positioned of channel bars  44  may be located adjacent front face  32 , with front end  43  and back end  45  positioned generally level with each other. With apex  46  extending above the level of front end  43  and back  45 , two distinct ramps may be formed on channel bar  44 , including a front ramp  94  and a rear ramp  96 . Front ramp  94  may define a relatively steeper entry into one of the shelves  40  to aid in the transition of a cylinder  22  into or out of cage  10 . Rear ramp  96  may define a shallower angle to provide a positively sloped location to aid in the retention of cylinder  22  within cage  10 . Alternatively, front end  43  and back end  45  may be located at different levels with respect to each other, so that a positive angle of for shelf  40  may be defined by channel bars  44 . In such a configuration, front end  43  of channel bar  44  may include a shape to aid in the transition of a cylinder  22  into and out of cage  10 .  
      Access doors  48  may be connected to front face  32 . Access doors  48  may be attached to the front face  32  by a removable hinge  50  or by other movable connections. While removable hinges are shown, it is anticipated that other removable and non-removable hinges or others movable mounting arrangements may be used within the scope of the present invention. Alternatively, access doors  48  may be permanently mounted to front face  32  or to some other portion of frame  27 . Access doors  48  may be secured with a chain  52  that extends through and locks into a pigeon hole  54 . Chain  52  may be attached to one of the access doors  48  with pigeon hole  54  attached to rigid front face  32 . It is anticipated that other door securing mechanisms may be used to secure one or both access doors  48  within the scope of the present invention.  
      Lift receptacles  24  may be attached to support base frame  28  and a lowest horizontal shelve  56 . Lift receptacles  24  may also include a hand truck cut out  26 . Conventional hand trucks for moving objects such as cage  10  may include wheels or rollers that need to be positioned closer to the load to be carried, due to the design and weight of the load and the lifting device. Alternatively, lift receptacles  24  may not include cut outs  26 , and be configured for use with fork lifts or other similar lifting devices. Cylinder holding cage  10  may be provided with a metal construction but other materials of similar strength and ruggedness may also be used.  
      As illustrated in  FIG. 4 , cylinder holding cage  10  loaded with cylinders  22  may be transported by an operator  58  using a hand truck  60 .  
      Referring to  FIG. 5 , cylinder holding cage  10  is loaded with cylinders  22 . Each cylinder  22  may have a gas level indicating device  62 , which either physically or procedurally indicates the gas level or status of cylinders  22 . Cylinders  22  may be stored between pairs of channel bars  44 , which may be configured as described above to provide a positively sloped or angled resting location for cylinders  22 . Access doors  48  may be secured by inserting chain  52  into pigeon hole  54 . Access doors  48  may be configured to permit inspection of gas level indicating device  62  without requiring doors  48  be opened.  
      An alternative embodiment cylinder holding case  100  is shown in  FIG. 6 . Cylinder holding case  100  includes shelves  140  without channel bars. Cylinder holding cage  100  may include support bars  42  and is shown with all cylinders  22  removed. Access doors  48  may be similarly secured by connecting chain  52  to pigeon hole  54 . Cylinder holding cage  100  is also shown with lift receptacles  24  including hand truck cut outs  26 . As shown, shelves  140  may also include a front end  143  and a back end  145  which are generally level with each other, and an apex  146  adjacent front face  32 . A front ramp  1   94  is defined between apex  146  and front end  143  to aid transition of cylinders  22  into and out of cage  100 . A rear ramp  196  is defined between apex  146  and rear end  145  and provides a positively angled resting location for cylinders  22 . Alternatively, front end  143  and rear end  145  maybe positioned not level with each other so that a positively angled resting location for cylinders is formed on shelf  140 . Additional shapes or features may be included adjacent front end  143  to aid transition of cylinders  22  into and out of cage  100 .  
      Referring to  FIG. 7 , truck  14  is shown with storage compartment access doors  18  in an open position. Cylinder holding cage  10  is positioned inside storage compartment  16 . Access door  48  to cylinder holding cage  10  is also in the open position. An operator  58  is filling cylinders  22  with gas using a gas delivery device  64 . Gas delivery device  64  includes but is not limited to flexible or stationary hoses or piping systems, and some type of valve, as known in the technology of gas delivery. Operator  58  fills cylinders  22  until the gas level measuring device  62  indicates that the cylinder  22  is filled to a desired level.  
      Referring to  FIG. 8 , a single cylinder hand truck  66  may include a support base frame  68  connected to a vertical support beam  70 . Support base frame  68  may include a front plate  72 , a back plate  74  and side plates  76 . Vertical support beam  70  may connect to the support base frame  68  at an off-center position. Support beam  70  may be positioned closer to back plate  74  than to front plate  72 . Support base  68  may include two front stationary wheels  78  and at least one movable rear wheel  80 . Support beam  70  may extend to and connect with a horizontal platform  82 . Horizontal platform  82  may include two horizontal beams  84  that form a channel  85  configured to hold one of the cylinders  22 . Horizontal beams  84  may have receptacles  86  that secure single cylinder hand truck  66  to cylinder holding cage  10 . Horizontal beams  84  may connect to a cylinder holding clamp  88 . Horizontal platform  82  may be raised to lowered vertically to a desired position relative to one of the cylinders  22  held within cylinder holding cage  10  by operator  58  utilizing a hand crank  90 , which may be linked with powered by a mechanical pulley system or other mechanical advantage device (not shown).  
      As illustrated in  FIG. 8 , operator  58  may secure single cylinder hand truck  66  to cylinder holding cage  10  utilizing receptacles  86 . This may be accomplished by opening the access door  48  and attaching receptacles  86  to shelves  40 . After this attachment is completed, one of the cylinders  22  can be transferred to single cylinder hand truck  66  utilizing channel  85  defined by horizontal beams  84 . Cylinder  22  may then be secured to single cylinder hand truck  66  using cylinder holding clamp  88 .  
      An alternative embodiment of a single cylinder hand truck  166  is shown in  FIG. 9 . In single cylinder hand truck  166 , the vertical position of horizontal platform  82  may changed by an operator (not shown) utilizing an electric motor  92  which may directly move platform  82  to different vertical positions or which may be linked to a mechanical pulley system or other mechanical advantage device (not shown).  
      As illustrated in  FIG. 10  and  11 , single cylinder hand truck  66  (or  166 ) is secured to cylinder holding cage  10 . Receptacles  86  may temporarily attach to shelves  40  to form a secure connection. A corresponding cylinder  22  may then be transferred to single cylinder hand truck  66  (or  166 ) utilizing channel  85  created by horizontal beams  84  and secured by using cylinder holding clamp  88 .  
      The present invention provides methods and apparatus for a pressurized gas cylinder delivery system, which permits rapid loading, unloading and refueling of gas cylinders. The transportation system may include transportation equipment, such as a truck, and a cylinder holding cage which may be used to deliver the cylinders.  
      cylinder handling and delivery method may be carried out using one or more cylinder holding cages positioned within a truck or other transportation equipment. First, with the truck at a cylinder refueling site, cylinders held by the cylinder holding cage may be filled or charged with gas using a gas delivery device, while the cylinders are on the truck and within the cylinder holding cage. The gas delivery device may be external to the truck. Next, the truck may be moved to one or more customer locations. At a customer location, a cylinder holding cage with full cylinders may be unloaded from the truck using a lifting device, such as a fork lift or a hand truck which directly engages the cylinder holding cage. A cylinder holding cage with empty cylinders from the customer location may then be loaded into the truck using the lifting device. Finally, the truck may return the cylinder holding cages with the empty cylinders to the cylinder refueling site. The lifting device may be carried on the truck or may be provided at the customer location.  
      In other embodiments, the cylinder holding cages are initially placed on a surface; filled with cylinders and loaded into the truck. The truck may adapted to store a forklift on the truck&#39;s exterior. Single cylinders may be delivered from the cylinder holding cage using a smaller lifting device, such as a single cylinder hand truck. The cylinders may have a gas level indicating device that indicates the amount of gas present in the cylinder. Individual cylinders may be unloaded from a cylinder holding cage at each of a plurality of customer locations before returning to the cylinder refueling site.  
      The cylinder holding cages used in the truck may have a rigid frame formed from a top face, bottom frame and sidewalls, with a plurality of shelves positioned between the top face and bottom frame and extending between the sidewalls. The cylinder holding cages may include at least one movable door allowing access to a plurality of cylinder locations defined on the shelves. Such movable doors may include but is not limited to a hinged door, sliding door or porous screen. The bottom frame may have at least one receptacle secured to the bottom frame below the first shelf. The receptacle may be adapted to allow a variety lifting devices to lift and move the cylinder holding cage. The plurality of shelves may be configured to allow the cylinders to be storage generally horizontally.  
      The hinged door may have some type of lock, including but not limited to mechanical, chemical or electrical locks, to keep the door closed and prevent removal of a cylinder from a shelf. The cylinder holding cage&#39;s shelves may have an upwardly convex surface or a plurality of channels defining ramps that may aid in holding cylinders within the shelves and to aid in the transition of cylinders into and out of the cylinder holding cage. The cylinder holding cage may have a plurality of support beams attached between the vertically sequenced shelves.  
      A cylinder holding cage and a single cylinder hand truck may used in combination to handle and transport individual pressurized gas cylinders. The single cylinder hand truck may have a base with a top, bottom and sidewalls. The base may include two front stationary wheels and at least one movable rear wheel and at least one generally vertical support beam. The vertical support beam may have a vertically movable horizontal platform with at least two horizontal beams that form a channel to hold at least one cylinder. The single cylinder hand truck may have horizontal beams, which include at least one receptacle that secures to a cylinder holding cage. The single cylinder hand truck may have at least one clamp mounted to one of the horizontal beams to secure a cylinder in place on the hand truck. Movement of the horizontal platform vertically may be by means of various mechanisms, which may include but are not limited to a mechanical pulley system or an electrical motor. The single cylinder hand truck may include a handle attached to the vertical support beam to facilitate movement of the hand truck by an operator.