Patent Publication Number: US-4092974-A

Title: Pocket camp stove

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to small gas stoves for outdoorsmen, and in particular to such a stove which is foldable into a compact, pocket-size package. 
     2. Description of the Prior Art 
     Various types of small stoves have been proposed and/or marketed for use by campers and other outdoorsmen. However, the known stove of this type do not satisfy the need for a stove which is extremely simple in construction, is easy to assemble and use, and when not in use can be collapsed and stored in a quite small pocket shape storage space. It is the primary object of this invention to provide a lightweight pocket size camp stove which fulfills this need. 
     SUMMARY OF THE INVENTION 
     The portable gas stove of this invention is basically characterized by a burner support hub member; a plurality of leg members which are connected to the hub member, each of which includes a lower foot portion restable on a support surface and an upper pan supporting portion; and a gas burning unit positionable on the support hub. The gas burner unit includes a burner head which extends upwardly from said hub to a level below the level of the pan supporting portions of the legs. A gas supply conduit is connected to the burner unit and extends therefrom to a connector which is especially adapted for connecting it to a can of gaseous fuel under pressure of a type having a depressable member controlled outlet valve built into the can. The connector includes a valve means which is operable for moving the depressable member a selected amount for both turning the gas flow on and off and regulating its flow rate. 
     According to an aspect of the invention, the connector comprises a first adapter member which is attachable to an upper portion of a can of gaseous fuel of the type described. Such member includes an upstanding, externally threaded tubular stem that, when said member is installed on a can of gaseous fuel, is generally concentric with the depressable control member of the outlet valve built into the can and such depressable control member projects upwardly into the interior of the tubular stem. The connector also includes a second member in the form of a rotatable control cap having internal threads matable with the external threads of the stem. A third member is affixed to the end of the flexible hose and includes a socket for engaging the depressable member on the can. The rotatable control cap is rotatable about the third member but is otherwise fixed in position relative to the third member. As a result of this arrangement, when the control cap is rotated in the direction causing it to screw itself onto the threads on the stem of the first member it causes the third member to be moved axially inwardly to contact and depress the depressable member. The control cap is rotatable between an off position in which the third member does not depress the depressable member enough to cause any flow of gas out from the can to a fully open position in which the depressable member is substantially fully depressed and there is a maximum flow of gas out from the can. 
     According to another aspect of the invention, each leg member is formed from a piece of wire and comprises a first end portion which is insertable into a lower socket formed for it in the hub member, and said leg member extends downwardly from said end portion to form a lower foot portion, and from said lower foot portion extends upwardly to form an upper pan supporting portion, and then extends downwardly to a second end portion which is received within an upper socket formed for it in the hub member. The two end portions of each wire leg member function as trunnions, so that the leg members can be folded between a stowage position in which all of the leg members are relatively together and an in use position in which the leg members are spaced apart and extend substantially radially outwardly from the hub member. 
     These and other features, objects and advantages of the invention will be apparent from the preferred embodiment which is illustrated in the drawing and described below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     In the drawing like element designations refer to like parts, and 
     FIG. 1 is an isometric view of an embodiment of the invention in its operative condition; 
     FIG. 2 is an isometric view of the hub member and leg assembly, showing the legs folded; 
     FIG. 3 is a fragmentary elevational view of the stove, showing one leg and the burner head in elevation and the hub member in vertical section; and 
     FIG. 4 is a vertical section view of the control valve and adapter assembly. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawing more specifically, the stove is shown to comprise a hub member 10 to which a plurality of leg members 12 are connected. Each leg member 12 includes a first end portion 14 which extends generally vertically and is insertable into a lower socket formed for it in a portion of the hub member 10. The wire forming the leg member 12 extends from end portion 14 first laterally and then downwardly to form a support foot 16, and from said support foot 16 extends upwardly and outwardly to the outward end of a generally horizontal pan support portion 18. FIG. 3 includes a broken line showing of a pan 19. The wire then extends from the inner end of the pan support portion 18 both inwardly and downwardly to a second end portion 20 which extends into a socket formed for it in the upper portion of hub member 10. The two end portions 14, 20 and the two sockets therefore are axially aligned, and serve to mount the leg member 12 for rotation between a folded position and an in use position. When they are in their in use positions the leg members 12 are substantially evenly spaced apart and extend substantially radially outwardly from the hub member 10. Hub member 10 may be formed to include a lock notch 22 which is in position to engage the wire member. However, this construction allows the leg members 12 to be easily moved angularly in position out from engagement with the notches. The wire snaps into and out from the notches. When in their folded condition, all of the leg members are relatively close together, as shown by FIG. 2. The hub member 10 is formed to include an upwardly directed recess which receives a base portion 24 of a burner unit 26. The recess also receives the inner portion of an inlet stem 28. The burner unit 26 includes a burner head 30 which is quite conventional in construction and is adapted to mix atmospheric air with a gaseous fuel to form a combustable mixture. 
     A flexible fuel supply hose 32 is attached to the outer end of the inlet pipe 28. At its end opposite inlet pipe 28 the hose 32 is attached to a tubular member 34. A control knob member 36 is mounted onto hose 32 for rotation in position about member 34. However, members 34, 36 are fixed in position axially. The member 34 includes an axial central passageway which is a continuation of the passageway through hose 32. The end part of the passageway forms a socket for receiving the upper end portion 38 of a depressable control member 38 which is a portion of an outlet valve mechanism 40 built into the fuel can 42. The depressable member 38 includes an axial passageway through which the gaseous fuel flows when leaving the can 42. Opening and closing of this passageway is controlled by movement of the member 38. The valve mechanism is constructed so that the flow rate of the gaseous fuel out from can 42 is proportional to the amount of depression of control member 38. 
     The stove includes an adapter member 44 having a base portion 46 which is preferably plug fitted onto the upper portion of can 42. That is to say, it includes a lower tubular neck portion which is sized onto and frictionally engage an upper portion of the can 42. Member 44 includes an upstanding externally threaded tubular stem 48. When member 44 is positioned on can 42, the depressable control member 38 projects upwardly part way into the interior of the stem 48. Control cap 38 includes internal threads which are matable with the external threads on stem 48. As will be appreciated, rotation of the control stem 36 in the clockwise direction will cause the control cap to move axially downwardly relative to stem 48. This causes member 34 to also move axially downwardly and as it moves it depresses the valve member 38. The member 44 may be provided with indicia on its upper surface 50 for indicating an off position (in which member 38 is not depressed at all) and a fully open position (in which member 38 is fully depressed). 
     The burner is prepared for use in the following manner. The base assembly comprising the hub member 10 and the leg member 12 is removed from the storage pocket. The leg members 12 are swung apart until they snap into the notches 22. Then the several pieces of the burner assembly are attached together and the base portion of the burner assembly, and the inlet pipe 28, are set downwardly, into the recess formed in hub member 10. Next, adapter member 44 is snap fitted onto the top of the fuel can 42. Then, control cap is loosely joined with the stem 48. The camp stove is now ready to be turned on in the following manner. With the stove set up on a substantially level surface, a lighted match is held next to the burner head 30 and the control cap 36 is turned clockwise until the burner lights. The control cap 36 is then turned an additional amount while watching the flame until a substantial body of flame is present. Care must be taken to maintain the fuel can 42 spaced away from the flame and in an upright position. The heat ranges from simmer to about 1,600°F) and may be regulated by the control cap 36. 
     The stove is prepared for packing by first turning the control cap 36 counterclockwise until the flame is extinguished. Then, the stove is allowed to cool for about 5 minutes or more. In the meantime, the control cap 36 is completely removed from stem 48 and the adapter member 44 is removed from the fuel can 42. Following sufficient cooling, the burner members 24, 28, 30 are removed from the support head 10. The legs 12 are then swung inwardly together to their folded position. Then, this assembly of hub member 10 and legs 12, and the other components 18, 24, 28, 30, 32, 34, 36, 44 may be placed back into their storage packet. 
     The stove can be fueled by an 8 fluid ounce can of butane gas or the like of the type which is marketed for use in filling cigarette lighters, etc.