NL2031022A - Combustion-Powered Fastener Driving Tool Fuel Supply Canisters and Fuel Supply Canister Valve Assemblies - Google Patents

Abstract

A valve assembly 16 for a combustion-powered fastener driving tool fuel supply canister comprising a valve stem that has a discharge end 48 and a delivery passage 56 to deliver 5 fuel in a first direction from an upstream end to the discharge end. The discharge end 48 has at least one outlet aperture 80 connected with the delivery passage configured such that when, in use, a valve stem piston of a combustion-powered fastener driving tool engages the discharge end to press valve stem in a second direction opposite to the first direction, the at least one outlet aperture is at most only partially occluded by the valve stem piston whereby 10 the fuel can flow out of the at least one outlet aperture in the first direction.

Description

Combustion-Powered Fastener Driving Tool Fuel Supply Canisters and Fuel Supply Canister Valve Assemblies Field of the Invention The invention relates to combustion-powered fastener driving tool fuel supply canisters and fuel supply canister valve assemblies.

Background to the Invention It is known to provide fastener driving tools with a striking mechanism that 1s operable to apply an impact to a fastener to drive the fastener into a substrate.

Such fastener driving tools are often referred to as nailers or nail guns, although, they are not limited to use with nails.

Some fastener driving tools generate the force that drives the striking mechanism by combusting a fuel gas.

The fuel may be supplied from a fuel supply canister that when empty is removed from the fastener driving tool to allow fitting of a replacement fuel supply canister.

A combustion-powered fastener driving tool fuel supply canister may comprise an outer container, an inner container housed within the outer container and a valve assembly secured to both the inner and outer container.

The inner container is a flexible body that contains the fuel and the space defined between the inner and outer containers contains a propellant that applies an external pressure to the inner container.

The valve assembly comprises a valve stem that when depressed allows fuel to flow from the inner container urged by the pressure applied by the propellant.

Usually, the valve stem 1s depressed automatically when the fuel supply canister is loaded into the fastener driving tool and the flow of fuel from the fuel supply canister is controlled by a valve in the tool.

EP2 767 366 discloses a combustion-powered fastener driving tool and fuel supply canister.

When the fuel supply canister is inserted into the tool, the valve stem is depressed by engagement of a discharge end face of the valve stem with a spring-loaded valve stem piston.

The valve stem has a longitudinally extending delivery passage via which fuel from the fuel supply canister is channelled to an outlet aperture provided in a side wall of the valve stem.

The outlet aperture is defined by a relatively short passage that extends perpendicular to the delivery passage between a downstream end of the delivery passage and the side wall of the valve stem. Thus, fuel exiting the fuel supply canister turns through 90 degrees while flowing along relatively narrow passages defined within the valve stem. This convoluted flow path increases the likelihood of blockages forming. Blockages may be caused by a build-up of lubricant or debris.

Summary of the Invention The invention provides a combustion-powered fastener driving tool fuel supply canister as specified in claim 1.

The invention also includes a valve assembly for a combustion-powered fastener driving tool fuel supply canister 13. The invention also includes a method of delivering fuel to an inlet of a combustion-powered fastener driving tool as specified in claim 19.

The at least one outlet aperture of the fuel supply cannister or valve assembly 1s configured such that the fuel flowing in the first direction along the delivery passage of the valve stem is able to flow out of the at least one aperture while still flowing at least substantially in the first direction. The flow of fuel does not have to make a substantial change of direction when exiting the discharge end of the valve stem or while flowing within the valve stem. Brief Description of the Drawings In order that the invention may be well understood, some examples thereof will now be described with reference to the drawings in which: Figure 1 shows a partially disassembled combustion-powered fastener driving tool fuel supply canister comprising an outer container, a fuel container bag and a valve assembly; Figure 2 is a schematic part-sectioned view of a central portion of the valve assembly of the fuel supply canister; Figure 3 is an enlarged sectioned view on line II-I of Figure 2;

Figure 4 is a perspective view of a valve stem member of the valve assembly of Figures 2 and 3; Figure 5 is a schematic cross-section view of the fuel supply canister of Figures 1 to 4 engaging a fuel entry assembly of a combustion-powered fastener driving tool; Figure 6 is a view corresponding to Figure 4 showing a modified valve stem member; Figure 7 is an end view of a valve stem of another example of a valve assembly of a fuel supply canister; Figure 8 is a section on line VII-VII in Figure 7; Figure 9 is a perspective view of another valve stem member of a valve assembly of a fuel supply cannister; and Figure 10 is a schematic illustration of a valve stem piston of a combustion-powered fastener driving tool engaging a discharge end of the valve stem member shown in Figure 9. Detailed Description In the description that follows, references to ‘top’, ‘bottom’, ‘underside’, ‘upper’, ‘lower’, ‘inner, ‘outer’ and the like are to the orientation of parts shown in the drawings and since the orientation of the parts may vary when in use, they are not to be taken as limiting.

Also, in order to better illustrate the examples, the features shown in the drawings may not be drawn in proportion.

Referring to Figure 1, a fuel supply canister 10 comprises a hollow outer container 12, a fuel container bag 14 and a valve assembly 16. The fuel container bag 14 is secured to the valve assembly 16 prior to insertion into the outer container 12. When the fuel container bag 14 is disposed in the outer container 12 and the valve assembly 16 is secured to the outer container, a sealed volume is defined between the outer container and the fuel container bag to contain a propellant.

The outer container 12 1s an elongate body comprising a side wall 18 and a bottom wall 20 disposed at one end of the side wall. The bottom wall 20 may arch inwardly to provide the outer container with additional body strength. The opposite end of the side wall 18 defines a valve opening 22 and has a beaded, or rolled, edge 24 to provide a strong seat to which the valve assembly may be secured. The outer container 12 may have an at least substantially circular cross section and may be a metal body. For example, the outer container 12 may be an aluminium or aluminium alloy body that is formed by indirect, or backwards, extrusion followed by one or more forming operations to shape the second end of the side wall 18 and the beaded edge 24. In the illustrated example, the side wall 18 curves inwardly adjacent the valve opening 22. It is to be understood that this is not essential and that the side wall 18 may be at least substantially straight and in at least some examples, the outside diameter of the outer container 12 between the bottom wall 20 and the beaded edge 24 may be at least substantially constant.

The fuel container bag 14 is made of a flexible material such as a plastics material, metal foil or the like that is impervious to the both the fuel and the propellant. The fuel container bag 14 may be formed by disposing the two generally rectangular sides 26 (only one of which is visible in the drawing) in face-to-face relation and bonding, or sealing, them together around their respective peripheries 28 to define an interior space to contain a fuel.

Inthe illustrated example, the lower end of the fuel container bag 14 is formed by a fold and the sides and upper ends are formed by the sealing a of sides 26 to one another. The upper end of the fuel container bag 14 is provided with an opening 30 for fitting to the valve assembly 16.

Referring to Figures 1 and 2, the valve assembly 16 comprises a valve cup 32, which may be made of metal. The valve cup 32 is configured to fit over the valve opening 22 and be sealingly secured to the beaded edge 24 so as to provide a sealed space between the outer container 12 and the fuel container bag 14 to contain a propellant. The valve cup 32 may comprise a dished body that defines a rim configured to fit over the beaded edge 24 and a central depression 36 (Figure 5) containing a boss 38 that projects upwardly from the base of the depression. The underside of the valve cup 32 defines a circumferentially extending groove in which an annular sealing member is housed such that when the valve cup is fitted over the beaded edge 24, the sealing member is sandwiched between the beaded edge 24 and the valve cup.

The valve cup 32 may be secured to the outer container 12 by crimping the periphery of the valve cup onto the beaded edge 24. This may compress the sealing member to ensure that the join between the valve assembly 16 and outer container 12 is sealed. 5 Referring to Figures 2 and 3, the valve assembly 16 further comprises a valve stem 38, a valve stem housing 40 to which the fuel container bag 14 is attached, for example via a bag mounting member (not shown), and a valve seal 42. The valve stem 38 is an elongate structure having a longitudinal axis 44. In the illustrated example, the valve stem 38 comprises a first member 46 that extends through the valve opening 22 and a second member 48 fitted to the first member 46. The first member 46 has a discharge end 48 and an enlarged upstream end, or valve stem base, 50. The valve stem base 50 defines an annular surface 52 that extends transversely with respect to the longitudinal axis 44 of the valve stem 38 and faces both the valve seal 42 and the discharge end 54 of the valve stem.

The valve stem 38 defines a delivery passage 56 that extends from an upstream end at a position adjacent the annular surface 52 to a position adjacent and spaced from the discharge end 54. The valve stem 38 further defines at least one side passage 58 extending between the upstream end of the delivery passage 56 and the outer periphery, or side wall 60, of the first member 46 of the valve stem.

Although not essential, in the illustrated example there are four side passages 58 disposed in a common plane and spaced 90° degrees apart.

The or each side passage 58 and the annular surface 52 may be disposed at least substantially perpendicular to the longitudinal axis 46 of the valve stem 40. Referring to Figure 2, the valve stem housing 40 may be a generally cylindrical body provided with a through-passage having an upstream end and a downstream end.

The downstream end comprises a relatively wide recess defining a housing 62 in which the valve seal 42 is trapped between the valve cup 32 and the valve stem housing 40. The upstream end comprises a relatively narrow inlet passage 64 leading to a valve stem chamber 66 that extends between the inlet passage and valve seal housing 62. The valve stem chamber 66 houses the valve stem base 50 and a biasing member 68. The biasing member 68 is positioned between the underside of the valve stem base 50 and an annular biasing surface 70 defined by the change in diameter between the inlet passage 64 and the valve stem chamber 66. The biasing member 68 is configured to apply a biassing force to the valve stem 38 to cause the discharge end 54 to protrude from the outer container 12 and hold the valve stem in a closed condition in which the radially outer ends of each side passage 58 are covered by the valve seal 44. A valve open condition is obtained by applying an axially directed force to the discharge end 54 of the valve stem 38 to depress the valve stem against the biasing force of the biasing member 68 and move the side passages 58 into the valve stem chamber 66 to allow fluid flow from the fuel container bag 14 into the delivery passage 56 via the valve stem chamber 66 and the side passages 58. The biasing member 68 may comprise any suitable resilient member such as, for example, a compression spring.

Still referring to Figure 2 the valve stem base 50 has an outer diameter substantially equal to that of the wall 76 of valve stem chamber 66, so that the valve stem 38 is guided by wall 76 when moving between valve open and valve closed conditions. To assist the flow of the fuel past the valve stem base 50 when the valve stem 38 is in a valve open condition, the valve stem base may be provided with one or more lengthways extending passages 78 that may extend at least substantially parallel to the longitudinal axis 44 of the valve stem 38. The passage or each passage 78 may take the form of an open channel extending from the upstream end of the valve stem base 50 to the annular surface 52. Referring to Figures 3 and 4, the discharge end 54 of the valve stem 38 may be a generally planar surface provided with at least one outlet aperture 80. Although not essential, in the illustrated example there are two outlet apertures 80. The outlet apertures 80 are flow connected with the delivery passage 56 and are disposed intermediate and spaced from the longitudinal axis 44 of the valve stem 38 and the periphery 82 of the discharge end 54. The periphery 82 may be the edge at which the discharge end meets the side wall 84 of the second member 48 of the valve stem 38. In some examples, the periphery 82 may be defined by a circumferentially extending ridge. The outlet apertures 80 may be the same size and shape and may be disposed in opposed spaced apart relationship as shown in Figure 4. The arrangement of the outlet apertures 80 leaves a land 86 in the centre of the discharge end 54 that is centred on the longitudinal axis 44 of the valve stem 38.

Referring to Figures 3 and 4, the outlet apertures 80 may be generally arcuate slots. The outlet apertures 80 may be configured to extend along an arcuate pathway on a constant radius measured from the longitudinal axis 44. The outlet apertures may be configured so that their outer sides 88 are on the same radius as the wall 88 that defines the delivery passage 56 in the second member 48 of the valve stem 38. It is to be understood that this is not essential and, in some examples, the outer sides 86 may be on a radius greater than the radius of the wall 88. Although the illustrated example has two outlet apertures, in other examples, there may be just one outlet aperture or more than two outlet apertures, for example, three or four outlet apertures. In some examples (not shown), the outlet apertures may be crescent- shaped.

Optionally, the second member 48 of the valve stem 38 may be provided with a flange 90 disposed intermediate and spaced from the discharge end 54 and the valve stem base 50. As best seen in Figure 3, the leading edge 92 of the flange 90 may be radiused or otherwise relieved, for example by a chamfer.

As shown in Figures 3 and 4, optionally the leading end of the second member 48 of the valve stem 38 may comprise a reduced diameter nose portion 94 extending from the discharge end 54 towards the valve stem base 50. The nose portion 94 may be connected with the main body of the second member 48 of the valve stem 38 by a tapering portion 96. Referring to Figure 5, in use, the fuel supply canister 10 is typically inserted into a canister chamber 100 provided in a combustion-powered fastener driving tool. The fuel supply canister 10 is pushed firmly into canister chamber 100 with the valve stem 38 leading so that the valve stem can be pressed into engagement with a fuel entry assembly 102 disposed at the inner end of the chamber 100.

The fuel entry assembly 102 comprises an inner member 104 and an outer member 106. The outer member 106 defines recessing at its downstream end that is configured to receive the upstream end of the inner member 104. At least one seal, which may comprise an O-ring 107, is provided between the inner and outer members 104, 106. The inner member 104 defines a chamber 108 that houses a valve stem piston 110 and a biasing member 112. The biasing member 112 may be a compression spring and is arranged to apply a biasing force to the valve stem piston 110 that biases the piston towards the outer member 106. The outer member 106 defines an entry port 114 through which the nose portion 94 of the valve stem 38 can be inserted into the chamber 108 to engage the valve stem piston 110. In the absence of the valve stem 38, the biasing member 112 is able to bias the valve stem piston 110 to a position in which it blocks the entry port 114 to prevent the ingress of dust and dirt.

The entry port 114 houses a sealing member 116, which may comprise an O-ring. The sealing member 116 is engaged by the side wall 84 of the valve stem 38 and forms a seal between the outer member 106 and the valve stem 38. The entry port 114 may be provided with a recess 118 to receive the flange 90 of the valve stem 38. This may assist in at least one of accurately locating the valve stem 38 with respect to the fuel entry assembly 102 and stabilising the engagement between the valve stem and the fuel entry assembly.

The reduced diameter of the nose portion 94 and the tapering portion 96 of the valve stem 40 facilitate, or make easier, the passage of the valve stem 38 through the entry port 114 and sealing member 116 to allow the discharge end 54 to enter the chamber 108 and engage the valve stem piston 110. The valve stem piston 110 has a reduced section free end which is a contact end 120 that is engaged by the discharge end 54 of the valve stem 38. In the illustrated example, the contact end 120 is radiused so as to form a hemi-sphere or dome. The outlet apertures 80 are configured so that the contact end 120 can engage the land 86 of the discharge end 54 without blocking the outlet apertures 80.

The stiffness of the biasing member 68 is selected so that it is greater than the stiffness of the biasing member 112. Thus, when the valve stem 38 is pushed into the entry port 114 it is able to displace the valve stem piston 110 from a position in which the piston closes the entry port 114 and push it into the chamber 108. Once the valve stem piston 110 has been pushed into the chamber 108 far enough to clear the entry port 114 and the valve stem 38 has entered the chamber 108 sufficiently to allow the side wall 84 to sealingly engage the sealing member 106, a position is reached at which there is sufficient resistance provided to overcome the stiffness of the valve stem biasing member 68 so that as the insertion of the fuel supply cannister 10 into the chamber 94 is completed, the valve stem 38 is effectively depressed with respect to the valve cup 32. Typically, the combustion-powered fastener tool comprises a means, such as a closure member (not shown) for holding the fuel supply canister 10 in a fully inserted position in the fuel supply canister chamber 100.

The depression of the valve stem 38 relative to the valve cup 32 moves the at least one side passage 58 out of engagement with the valve seal 42 and into the valve stem chamber 66, thereby allowing the flow of fuel from the fuel container bag 14 through the inlet passage 64 into the valve stem chamber 66 and on into the valve stem delivery passage 56 via the at least one side passage 58. The fuel flowing along the delivery passage 56 is output into the chamber 108 via the outlet apertures 80. The fuel output into the chamber 108 is able to flow past the valve stem piston 110 and exit the chamber 108 via an output passage 122. Fuel entering the output passage 122 is conducted to a combustion chamber of the combustion-powered fastener driving tool. The flow of fuel in the output passage 122 may be controlled by an electrically actuated valve, in a conventional manner. The electrically actuated valve may be a solenoid valve.

The arrangement, or configuration, of the delivery passage 56 and outlet apertures 80 is such that fuel flowing from the valve stem chamber 66 into the chamber 108 is able to follow a substantially straight-line path and there are no sharp turns or bends that may facilitate the forming of blockages or the like. As shown by Figures 2 and 3, flow of the fuel from the inlet passage 64 and out through the outlet apertures 80 will be substantially axial along the longitudinal axis 44 of the valve stem 38.

Figure 6 shows a modification to the second member 48 of the valve stem 38. Instead of a generally flat land 86 between the outlet apertures 88, the discharge end 54 may be provided with a recess 86R that is configured to receive the contact end 120 of the valve stem piston

110. The engagement of valve stem piston with the recess 86R may assist in centring and supporting the valve stem 140 during the insertion, or installation, process. In the illustrated example, the valve stem piston 110 has an at least substantially hemispherical contact end 120 and the recess 86R is a depression configured to complement the curvature of the contact end 120. It will be appreciated that in other examples, the contact end 120 may have a different shape and that the recess 86R would be configured to complement that shape. For example, the contact end 120 may be frusto-conical.

In the illustrated example, there are two symmetrically arranged outlet apertures 80. Although it may be convenient to provide two symmetrically arranged outlet apertures 80, in principle there may be just one outlet aperture of more than two. In examples in which there are more than two outlet apertures and the discharge end 54 is provided with a recess 86R, the recess may be disposed intermediate the outlet apertures, which may be disposed in equidistant spaced apart relationship on a common pitch circle.

Figures 7 and 8 show another example of a discharge end 154 of a valve stem 138. The valve stem 138 differs from the valve stem 38 in the configuration of the outlet aperture 180 and, in particular, in that it has one outlet aperture and no centrally disposed land. In this example, the outlet aperture 180 comprises a central portion 182 that is an extension of the delivery passage 156 and may have a circular cross-section having the same diameter as the delivery passage. The outlet aperture 180 further comprises at least one extension portion 184 that extends outwardly from the central portion 182. The or each extension portion 184 has a radially outer end 186 that is disposed radially inwardly and spaced from the periphery 188 of the discharge end 154 of the valve stem 138. In the illustrated example, there are two extension portions 184 disposed in opposed spaced apart relationship on opposite sides of the central portion 182.

In use, if the fuel supply canister 10 is provided with a valve stem 138, when the valve stem enters the chamber 108 via the entry port 114 and the discharge end 154 engages the contact end 120 of the valve stem piston 110, the tip of the contact end 120 enters the central portion

182. The engagement of the tip of the contact end 120 in the central portion 182 may assist in centring and supporting the valve stem 140 during the insertion, or installation, process. Once installed, fuel from the fuel container bag 14 may flow into the delivery passage 156 in similar fashion to that described above in connection with the valve stem 38 and, although the tip of the contact end 120 blocks the central portion 182 of the outlet aperture 180, the fuel is able to flow past the contact end 120 via the or each extension portion 184. Thus, the flow of fuel from the upstream end of the delivery passage 156, though the outlet aperture 180 and into the chamber 108 may be along at least substantially straight lines.

In some examples there may be just one extension portion 184. However, having multiple extension portions 184 may be provided improved flow characteristics. To increase the overall cross-sectional area of the extension portions 184, they may be made relatively deeper as compared with the extension portions 184 shown in Figure 7. Additionally, although for the sake of simplicity the extension portions 184 are shown as rectangular recesses with an innermost wall 190 that extends perpendicular to the longitudinal axis 144, it may be desirable to incline the innermost wall 190 with respect to the longitudinal axis 144 in order to provide a smoother flow path as indicated by the dashed lines 192 in Figure

8. It will also be understood that it is not essential that the walls defining the extension portions 184 are planar. The or each extension portion may be defined by an arcuate wall that is, optionally, inclined with respect to the longitudinal axis 144. In some examples, the centrally disposed land of a valve stem such as the valve stem 38 shown in Figures 3 and 4 to may be provided with a formation configured to receive the contact end 120 of the valve stem piston 110 to provide centring and support for the valve stem during the installation process. Figure 9 is a perspective view showing a second member 248 that may be provided in a valve assembly such as that illustrated by Figures 2 to 4 in place of the second member 48. Parts of the second member 248 the same as, or similar, to parts of the second member 48 are indicated by the same reference numeral incremented by 200 and may not be described in detail. The second member 248 differs from the second member 48 in that it has a single outlet aperture 280 that may be centred on the longitudinal axis of the valve stem. The outlet aperture 248 may be a rectangular aperture. In some examples, the rectangular aperture may be square, although, in the illustrated example it is oblong. The configuration of the rectangular outlet aperture 246 is such that when engaged by the valve stem piston 110, it is not fully occluded. Thus, fuel is still able to flow from the outlet aperture. As best seen in Figure 9, an oblong outlet aperture 280 provides the advantage that a greater area of the outlet aperture is not occluded by the valve stem piston 110, so that any restriction in the flow of fuel into the chamber 108 is reduced and the likelihood of blockage by dirt and the like is reduced. Furthermore, the flow of fuel from the upstream end of the delivery passage 256, through the outlet aperture 280 and into the chamber 108 may at least substantially be along a straight line. In the illustrated examples, the valve stem comprises two members. These members may be joined to one another, for example, by ultrasonic welding or an adhesive.

Claims (19)

S12 - Conclusions l. Fuel supply container for an internal combustion engine powered fastener driving tool, the fuel supply container comprising: a hollow container for containing fuel, the hollow container having a first end and a second end; a valve stem disposed on the first end, the valve stem having a longitudinal axis, a discharge end and a discharge passage for delivering the fuel from the hollow container to the discharge end; and a biasing member arranged to apply a biasing force to the valve stem to cause the discharge end to protrude from the first end of the hollow container, the discharge end being circumferential and having at least one outlet port connected to the dispensing passageway and wherein the at least one outlet port is located internally of the periphery and is configured so that when, in use, a free end of a valve stem piston of the internal combustion engine actuated fastener driving tool engages the discharge end to expel the valve stem internally of the hollow container against the biasing force, wherein the at least one outlet opening is at most partially closed by the valve stem piston through which the fuel can flow out of the at least one outlet opening. The fuel storage container of claim 1, wherein the at least one outlet opening is intermediately spaced from the longitudinal axis and the circumference. A fuel storage container according to claim 2, wherein the at least one opening comprises an arcuate slot and, preferably, the at least one arcuate slot extends along an arcuate path at a constant radius measured from the longitudinal axis. A fuel storage container according to claim 2 or 3, comprising two openings placed in opposing, spaced relationship. -13- A fuel storage container according to any one of the preceding claims, wherein the discharge end is provided with a recess to receive the free end of the valve stem piston, the recess being located on the longitudinal axis. The fuel storage container of claim 1, wherein the at least one outlet port comprises an outlet port having a central guide portion aligned with the longitudinal axis about, in use, the free end of the valve stem piston and at least one extension portion extending from the center guide portion. extends outwardly and has an outer end internally spaced from the periphery. A fuel storage container according to claim 6, comprising two extension portions, the extension portions being placed in opposite spaced relationship on opposite sides of the central portion. A fuel storage container according to claim 6 or 7, wherein the central guide portion has a circular cross-section and wherein one extension portion is a laterally extending rectangular recess extending from the central guide portion and wherein, preferably, the opening has a width defined by two opposing sides extending from the central guide portion and wherein the central guide portion has a diameter greater than the width. A fuel storage container according to claim 1, wherein the at least one outlet opening comprises a rectangular outlet opening and wherein, preferably, the outlet opening is elongated. The fuel supply container of claim 9, wherein the dispensing passageway has a longitudinal axis and wherein the rectangular outlet opening is centered on the longitudinal axis. 11. Fuel storage tank according to one of the preceding claims, in which the - 14 - discharge end comprises a flat surface and wherein, preferably, the discharge end is placed perpendicular to the longitudinal axis. A fuel storage container as claimed in any preceding claim wherein the valve stem comprises a first member extending through the first end of the hollow container and defining the upstream end of the dispensing passageway and a second member mating with the first member, the second element defines the discharge end. 13. A fuel tank valve assembly for an internal combustion engine power fastener driving tool, the valve assembly comprising: a valve stem disposed on the first end, the valve stem having a longitudinal axis, a discharge end, and a delivery passage for discharging the fuel to give in a first direction from an upstream end of the dispensing passage to the discharging end; and a biasing member arranged to apply a biasing force to the valve stem in the first direction, the discharge end being circumferential and having at least one outlet opening connected to the dispensing passageway and the at least one outlet opening being internal to the valve stem. circumferentially positioned and configured so that, in use, when a free end of a valve stem piston of the internal combustion engine actuated fastener driving tool engages the discharge end to push the valve stem interior of the hollow container against the biasing force, the at least one outlet opening is at most partially closed by the valve stem piston through which the fuel can flow from the at least one outlet opening at least substantially in the first direction. The valve assembly of claim 13, wherein the at least one outlet orifice is intermediate and spaced from the longitudinal axis and the circumference. The valve assembly of claim 14, comprising a plurality of outlets and - 15 - the discharge end being provided with a recess located between the outlets to receive the free end of the valve stem piston. The valve assembly of claim 13, wherein the at least one outlet port has a central guiding portion aligned with the longitudinal axis about, in use, the free end of the valve stem piston and at least one extension portion extending outwardly from the central guiding portion to an outer end thereof placed internally of the periphery. The valve assembly of claim 13, wherein the at least one outlet port has a rectangular outlet port. The valve assembly of any one of claims 13 to 17, wherein the valve stem includes a first member extending through the first end and a second member mating with the first member, the second member defining the discharge end. 19. A method of delivering fuel to an inlet of an internal combustion engine-powered fastener driving tool, the method comprising engaging a discharge end of a valve stem of an internal combustion engine-powered fastener driving tool with a valve stem piston of the internal combustion engine-powered fastener. including an internal combustion engine actuated fastener for causing the valve stem to be pushed internally of the internal combustion engine actuated fastener drive tool to open the valve stem to allow fuel to flow in a first direction to the discharge end, wherein the discharge end is provided with at least one outlet port configured such that at least one outlet port is not occluded by the valve stem piston allowing fuel to exit the at least one outlet port in the first direction.