BRIEF DESCRIPTION OF THE DRAWING
These and further features of the present invention will be better understood by reading the following Detailed Description together with the Drawing, wherein
FIG. 1 is a perspective view of one embodiment of the interlock according to the present invention as provided on an exemplary hand-held torch at an initial, interlocked stage of use;
FIG. 2 is a partial perspective view of the embodiment of FIG. 1, with the interlock de-activated;
FIG. 3 is a partial perspective view of the embodiment of FIG. 1, with the torch gas valve and ignitor activated;
FIG. 4 is an exploded view of the disposition of typical torch gas valve and ignitor elements according to the embodiment of FIG. 1; and
FIG. 4A is a further exploded view of the interlock according to the embodiment of FIG. 4.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT
The exemplary embodiment 50 of FIG. 1 according to the present invention is typically hand 40 held and operated by the thumb 42 which comes to rest on the exemplary interlock roller 64 retained by the movable top 54. The top 54 moves downward into the ignitor housing 52 when the interlock 60 tab 62 does not engage the top of the housing 52; however, as shown in FIG. 1, the tab 62 does engage the top of the ignitor housing and prevents the cap 54 from moving downward from thumb 42 or other forces, thus inhibiting the ability of the ignitor (72 of FIG. 4) within the ignitor housing from operating. Additionally, the cap 54 engages a gas valve lever (89 of FIG. 4) contained within torch head 58 to provide a flow of fuel from the fuel chamber 56 as the cap is depressed (if permitted by the location of the tab 62) and prior to the activation of the ignitor.
To operate the torch 50, the thumb (or other operating digit) is moved over the roller 64 to cause it to rotate about an axial pin 66 retained in the cap 54, either by tangential motion over the roller 64 surface, by engaging the roller 64 surface and moving the thumb in an arcuate manner 44, or a combination thereof. The result thereof is shown in FIG. 2, wherein the tab 62 is pivoted away from the surface 55 of the cap 54, with the greatest separation near the top of the ignitor housing 52, in preparation for a downward movement 46 by the thumb 42, which is now possible due to the disengagement of the tab 62 from the top of the ignitor housing 52.
As shown in FIG. 3, the top 54 is now depressed into the ignitor housing 52 while maintaining the rotation of the roller 64 providing the tab 62 to overhang the ignitor housing 52, releasing a fuel (gas) flow and providing ignition (e.g. an electric spark), resulting in the desired torch 50 flame.
A more detailed view of one embodiment of the interlock according to the present invention is shown in FIG. 4. The cap 54 is connected to the ignitor 72, which in this embodiment comprises a piezoelectric spark generator which provides a high voltage pulse on wire 73 which terminates at or near the region where the fuel (gas in this embodiment) and any other component (e.g. air, O2 etc.) needed for combustion, mix, whereupon a spark is produced which ignites the mixture to produce the flame (70, FIG. 3). The movement of the cap is typically defined by the ignitor 72 movable armature 71 which in this instance is along a vertical axis, along its length. The ignitor armature 71 is typically spring-loaded to extend out from the ignitor 72 but be receptive to compression forces which move the armature 71 into the ignitor 72 as applied to the cap 54 by a digit (e.g. thumb). At a distance along its inward travel, the armature causes the ignitor to generate the spark voltage applied to wire 73.
Simultaneously with the cap 54 movement to activate the ignitor 72, the fuel (gas) valve 80 is activated to provide a fuel flow through tubular member 84 by lever 86 having first extremities 89 engaging the cap 54 (on plate 57, FIG. 4A, attached thereto) which then pivots at 88 and causes the second extremities 85 to engage and open the fuel valve 80. In the present embodiment, the fuel valve 80 is disposed within or attached to the fuel chamber 56 or other container retained therein. The exemplary embodiment of FIG. 4 provides a fuel valve that opens by pulling along the axis 85 away from the valve 80 by engaging the tubular member 84 (with an internal spring to urge the tubular member into the valve 80 away from the movement of the second extremities 85) about a radial enlargement 86 by lever 86 second extremities 85 as the cap 54 is depressed. The present embodiment further provides an adjustment of fuel flow rate when the valve 80 is open by rotating the tubular member 84 about its axis 85 with radially attached adjusting lever 83, which typically adjust an orifice opening within the flow path of the valve 80, or as otherwise known in the art. Additionally, the valve 80 may be temporarily locked in the open position by a movable wedge, e.g. slidable in one dimension in this embodiment, to engage the second extremities 85 of the lever 86 when in the position that causes the valve 80 to be open, and may be retracted to allow the valve 80 to again be closed. Moreover, the valve 80 may be stabilized by plate 92 affixed to a housing member (not shown) with screw 93 or other fixing device. Furthermore, the movement of the cap 54 is guided by ears 94 extending outward to engage edges 95 (FIG. 3) of an aperture in head 58 of the exemplary torch embodiment 50.
A further expanded view of the interlock 60 is shown in FIG. 4A, wherein the tab 62 and roller 64 are shown as a single integrated element, which further includes a radially extending pin 65 which engages a slot (not shown) in the cap 54 to limit movement of the tab 62 away from the surface 55 (FIG. 2); movement of the tab 62 to the position where it engages the ignitor housing 52, is typically provided by merely resting against the surface 55 as urged by a spring 68 contained coaxially within the roller 64 which engages both the roller 64 and the cap 54 in the exemplary embodiment. The roller 64 is retained within the cap 54 between to appendages having apertures aligned with proper disposition of the roller 64 having spring 68 therein, adapted to receive a pin 66 therethrough. A plate 57 is attached to the cap 54 to receive the first extremities 89 of the lever 86 and provide a surface for reliable operation of the fuel valve as the cap 54 is moved downward.
Alternate embodiments envision other shapes of the roller as desired which provide the ability of the user to engage and rotate it about the pin 66 to move the tab 62 out of engagement of the housing 52. Moreover, the tab is shown extending somewhat tangentially from the roller, e.g. the tab 62 plane being offset from the axis of the pin 66, but other embodiment may include still further offset of the tab plane, or alignment thereof with the axis of the pin 66 in a manner which allows the tab 62 to disengage contact with the housing ignitor 52 or any other torch 50 structure to which the tab is interposed to inhibit movement of the ignitor, the fuel valve, or both. Further modifications or substitutions by one of ordinary skill in the art are within the scope of the present invention which is not to be limited except by the claims which follow.
Patent Application
20080044780
